Post Harvest Processing

Enzyme/Zinc Chloride Pretreatment of Short- Staple Cotton Fibres for Energy Reduction during Nano-Fibrillation by Refining Process

N. Vigneshwaran1*, Vilas Karande1, G.B. Hadge1, S.T. Mhaske2 and A.K. Bharimalla1 1Nanotechnology Research Lab, Chemical and Biochemical Processing Division, Central Institute for Research on Cotton Technology, 2Department of Polymer and Surface Engineering, Institute of Chemical Technology, Matunga, Mumbai–400019, India e-mail: [email protected]

Abstract—Cellulose is a renewable, biodegradable and the most abundant biopolymer available on the Earth. Natural Cellulosic fibers are synthesized mainly in plants and cellulose constitutes 40-50% of wood, 80% of flax and 90% of cotton fibers. Microfibrils are defined as the fibers of 0.1-1.0 μm diameter, with high aspect ratio and nanofibrils are at least one dimension in nanometer scale (1-100 nm). Nanofibrils of cellulose have potential use in high efficiency filters, tissue scaffolds and as reinforcing agent in composites. In this work, we have processed short-staple cotton fibres through refining process for the production of nanofibrils. The refining process, through shear force, pumps water into the secondary layer and loosens the compactness of fibrillar structure by disrupting the hydrogen bonding. To enhance the efficiency of refining process, pretreatments using enzyme / zinc chloride were developed to open up the primary layer. Cellulase enzyme pretreatment hydrolyzed the surface molecules in cellulose while zinc chloride act as a swelling agent thereby increasing the accessibility to secondary layer. Since the refining is a continuous process with very low residence time, minimum of 30 passes were required for complete fibrillation resulting in huge energy consumption. With pretreatments, the required number of passes for nano-fibrillation reduced drastically to fifteen only. Degree of polymerization of cotton fibres (11188) significantly reduced to 8144 in the case of fibrillation without pretreatment while it was 5147 and 6949 in the case of fibrillation with enzymatic and zinc chloride pretreatments, respectively. Energy required (for 20 g of cotton fibres) for initial 5 passes for fibrillation without pretreatment and enzyme and zinc chloride pretreatments are 1.346, 0.6764 and 0.8053 MJ, respectively. In subsequent passes, no significant difference was noticed. The pretreated fibres showed more than 50% reduction in energy consumption during refining process. The refining of the cotton fibers without pretreatment required at least 30 passes to achieve a fibril diameter of 400 nm whereas still smaller size (~100nm) could be achieved only in 15 passes using enzymatic / zinc chloride pretreatments. Nanofibrils of cellulose thus produced are now being evaluated for their use as fillers in biopolymer nanocomposites for use in food packaging.

INTRODUCTION Cellulose is a renewable, biodegradable and most abundant biopolymer available in the biosphere (Lee et al., 2009) and is produced in nature at an annual rate of 1011-1012 tons (Zhao et al., 2007). Cellulose is the main constituent of the plants serving to maintain their structure. The properties of cellulose like good tensile strength, low density, biodegradability etc. leads to rising research interest. Cellulose is the structural material of the fibrous cells with high level of strength and stiffness per unit weight and has a straight carbohydrate polymer chain consisting of β-1-4 glucopyranose units and a degree of polymerization of about 10,000 (Kamel, 2007). The molecules aggregate and are present in the form of microfibrils (Hult et al., 2003). The hydroxyl (-OH) groups in the cellulose structure play a major role in governing the reactivity and physical property of the cellulose. Natural Cellulosic fibers are synthesized mainly in plants and cellulose constitutes 40-50% of wood, 80% of flax and 90% of cotton fiber. In recent years, many researchers and manufacturers use natural fibers to replace man-made fibers as reinforcement material and fillers to make environmentally safe products. Cellulose fibers can be mechanically disintegrated to the structural nanoscale fibrils (Ahola et al., 2008).

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The word fibril has been described by various researchers to describe relatively long and very thin pieces of cellulosic material. Microfibrils are defined as the fibers of cellulose of 0.1-1μm in diameter (Chakraborty et al., 2005), with corresponding minimum length of 5-50 μm and nanofibrils are at least one dimension in nanometer scale (1-100 nm). The micro/nanofibrils isolated from the natural fibers have much better mechanical properties (Cao and Tan, 2002). Therefore much attention has been given in the last decade to study how to make micro/nano fibrils and how to combine them with the different polymers to make composites. In the present study, effect of enzymatic and zinc chloride pretreatments of cellulose on fibrillation of cotton fibers by refining process have been studied. The purpose of these pretreatments is to loosen the structure of the fiber either by reducing the secondary forces such as hydrogen bonding and van der Waals forces or by swelling the fibers. Pretreatments will also be helpful in obtaining cellulose nanofibrils in an energy efficient way. Nanofibrils from cotton fiber were prepared by top down approach using the Lab-Disc Refiner. The refining is a pulping method in which the fibers are separated from the matrix by means of mechanical forces. The main objective of the process is to loosen and separate the fibers from the matrix, to break the fiber layer, to peel the fiber cell wall to some extent, and to fibrillate fibers to the desired quality.

MATERIALS AND METHODS For enzyme pretreatment; about 20 g of cotton fibers were dispersed in 2 l of acetate buffer (pH 4.8) along with 1% of cellulase enzyme and stirring was done using mechanical stirrer at 45ºC for 30 min. After this, 10 ml of 1 M NaOH solution was added into the suspension to deactivate enzyme followed by washing with distilled water. For zinc chloride pretreatment; 71.5% solution of zinc chloride in water was prepared and allowed to cool as the exothermal reaction raised the temperature. After cooling, 20 g of cotton fibers were added into it and stirred for 1 h at 35ºC. Finally, the fibres were washed four times using distilled water to remove the zinc chloride completely. Cotton fibers before pretreatment and after the enzymatic / zinc chloride pretreatments were subjected to the refining process for fibrillation in a lab disc refiner. The output (fibrillated cotton fibers) from the fibrillation zone of refiner was collected in a vessel and one such process was completed in 2 minutes and considered as one pass. The sample was passed through the refiner up to 30 passes and characterization was done after every 5 passes. The schematic of entire process is given in figure 1.

Fig. 1: Typical Process for Preparation of Cellulose Nanofibrils The nanofibrils obtained by this process were analyzed by scanning electron microscopy, atomic force microscopy, and their degree of polymerization (DP) was analyzed by viscometric method. Simultaneously, the energy consumption was analyzed using the energy meter attached with the refiner. Enzyme/Zinc Chloride Pretreatment of Short-Staple Cotton Fibres for Energy Reduction During Nano-Fibrillation 473

RESULTS AND DISCUSSION The product obtained by refining process was analyzed by scanning electron microscopy and the obtained micrographs were subjected to image analysis as given in table 1. After the SEM analysis, diameter of the cellulose fibril was measured at 15 different locations of various images and an average diameter was reported.

TABLE1: DIAMETER OF THE FIBRILLATED COTTON (IN NM ± SD) FIBERS BEFORE PRETREATMENT AND AFTER ENZYMATIC, ZINC CHLORIDE PRETREATMENTS MEASURED FROM SEM IMAGES No. of Passes Control Cotton Fibres Enzymatic Pretreated Cotton Fibres Zinc Chloride Pretreated Cotton Fibres 5 809±0.53 339±0.18 272±0.014 10 709±0.46 334±0.20 204±0.14 15 617±0.50 142±0.07 206±0.22 20 533±0.47 146±0.14 168±0.10 25 473±0.38 154±0.10 170±0.12 30 452±0.35 152±0.09 174±0.11 From table 1 it has been observed that the diameter of the fibrillated before pretreatment has been reduced to 453 nm after 30 passes from an initial diameter of 21 µm. It is also observed that the diameter of the fibrillated cotton fibers after Enzymatic and Zinc Chloride pretreatments has been reduced down to 152 and 175 nm, respectively. The cotton fibers fibrillated even after 30 passes sample without any pretreatment has an average diameter of ~ 453 nm whereas less than this was achieved after 5 passes after enzymatic and zinc chloride pretreatments. Figure 2 shows the SEM micrographs of the fibrillated cotton fibres (enzyme pretreated) after every 5 passes; ‘a’ and ‘b’ corresponds to initial fibre while the figures from ‘c’ to ‘h’ represents stage after every 5 passes.

Fig. 2: SEM Micrographs of the Fibrillated Cotton Fibers After Enzymatic Pretreatment Figure 3 shows the SEM micrographs of the fibrillated cotton fibres (zinc chloride pretreated) after every 5 passes; ‘a’ and ‘b’ corresponds to initial fibre while the figures from ‘c’ to ‘h’ represents stage after every 5 passes. Also, the swelling of fibrils due to zinc chloride treatment is clearly visible in the SEM micrographs. 474 World Cotton Research Conference on Technologies for Prosperity

Fig. 3: SEM Micrographs of the Fibrillated Cotton Fibers After Zinc Chloride Pretreatment The AFM analysis of the fibrillated fibrils after 30 passes was carried out using silicon tip in a tapping mode. After the AFM analysis, diameter of the cellulose fibril was measured by image analysis and reported in table 2.

Enzyme/Zinc Chloride Pretreatment of Short-Staple Cotton Fibres for Energy Reduction During Nano-Fibrillation 475

TABLE 2: DIAMETER OF THE FIBRILLATED COTTON FIBERS BEFORE PRETREATMENT AND AFTER ENZYMATIC, ZINC CHLORIDE PRETREATMENTS MEASURED FROM AFM IMAGES Sample Avg. Diameter (nm) Before Pretreatment 432±0.11 Enzymatic Pretreatment 98±0.02 Zinc Chloride Pretreatment 156±0.07 Degree of polymerization is defined as the number of repeating units present in a polymer. Mechanical stresses generated due to shear, impact forces has great influence on chain scission and hence on degree of polymerization. During the fibrillation process cotton fibers are subjected to the shearing and impact forces therefore chain scission as well as fibrillation takes place which was resulted in significant reduction of degree of polymerization and diameter of the cellulose fibril. Table 3 provides the information about the DP of cotton fibres at different stages of fibrillation.

TABLE 3: DEGREE OF POLYMERIZATION OF THE FIBRILLATED COTTON FIBERS BEFORE PRETREATMENT AND AFTER ENZYMATIC/ ZINC CHLORIDE PRETREATMENTS No. of Passes Control Cotton Fibres Enzymatic Pretreated Cotton Fibres Zinc Chloride Pretreated Cotton Fibres Control 11188±21.08 8062±23.41 10032±21.92 5 9183±22.55 7307±23.99 8749±22.88 10 8342±40.19 6742±24.43 8210±23.30 15 8227±23.30 6690±24.48 8128±46.70 20 8161±23.33 5526±25.40 8078±23.41 25 8111±23.37 5220±31.43 7929±23.52 30 8128±23.37 5165±25.70 6949±24.27 From table 3, it is observed that the degree of polymerization was reduced to 5165 and 6949 after enzymatic and zinc chloride pretreatments, respectively; while that of pristine fibres was 8128. The degree of polymerization reduction may be attributed to the continuous exposure of cotton fibers to the mechanical forces when subjected to the Lab disc refiner. Energy consumption during the fibrillation process is a major prohibitive factor for carrying out nanofibrillation. So, reduction in energy consumption will be a major boost for the production of nanofibrils. Table 4 shows the energy requirement for fibrillation after different pretreatments.

TABLE 4: ENERGY REQUIRED FOR FIBRILLATION OF COTTON FIBERS BEFORE PRETREATMENT AND AFTER ENZYMATIC, ZINC CHLORIDE PRETREATMENTS No of Passes Energy Required ( MJ) Before Pretreatment After Enzymatic Pretreatment After Zinc Chloride Pretreatment 5 1.346 0.6764 0.8053 10 0.8425 0.6519 0.7139 15 0.747 0.6386 0.7448 20 0.805 0.6152 0.7038 25 0.8515 0.6091 0.6516 30 0.754 0.626 0.6368 Initially more energy was required for fibrillation and as the number of passes increased less energy was required. Before pretreatment initial energy consumption was more and after the pretreatments, it reduced significantly. After 5 passes, the energy required was almost 50% less for the enzyme pretreated cotton fibres compared to that of pristine fibres.

CONCLUSION The enzymatic and zinc chloride pretreatments have significant effect on the fibrillation of the cotton fibers. The finest fibrils were obtained after fibrillation of the enzyme pretreated fibers and the diameter of the fibril was reduced to ~98 nm from an initial value of ~ 21 µm. The degree of polymerization has been significantly decreased after the fibrillation of enzyme and zinc chloride pretreated fibres. It has also observed that both enzymatic and zinc chloride pretreatments have significant effect on energy reduction and among the pretreatments, enzymatic pretreatment performs better.

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ACKNOWLEDGEMENT Financial support for this work was provided by National Agricultural Innovation Project (NAIP), Indian Council of Agricultural Research (ICAR) through a sub-project entitled Synthesis and characterization nanocellulose and its applications biodegradable polymers composites to enhance their performance properties (417101).

REFERENCES [1] Ahola, S., Salmi, J., Johansson, L.S., Laine, J. and Osterberg, M. (2008) - Model films from native cellulose nanofibrils. Preparation, swelling, and surface interactions. Biomacromolecules 9:1273-82. [2] Cao, Y. and Tan, H. (2002) - Effects of cellulase on the modification of cellulose. Carbohydrate Research 337:1291-1296. [3] Chakraborty, A., Sain, M. and Kortschot, M. (2005) - Cellulose microfibrils: A novel method of preparation using high shear refining and cryocrushing. Holzforschung 59:102-107. [4] Hult, E.L., Iversen, T. and Sugiyama, J. (2003) - Characterization of the supermolecular structure of cellulose in wood pulp fibres. Cellulose 10:103-110. [5] Kamel, S. (2007) - Nanotechnology and its applications in lignocellulosic composites, a mini review. eXPRESS Polymer Letters 1:29. [6] Lee, S.-Y., Mohan, D., Kang, I.-A., Doh, G.-H., Lee, S. and Han, S. (2009) - Nanocellulose reinforced PVA composite films: Effects of acid treatment and filler loading. Fibers and Polymers 10:77-82. [7] Zhao, H., Kwak, J.H., Conrad Zhang, Z., Brown, H.M., Arey, B.W. and Holladay, J.E. (2007) - Studying cellulose fiber structure by SEM, XRD, NMR and acid hydrolysis. Carbohydrate Polymers 68:235-241. 79

Optimal Cotton Covered Jute, Nylon and Metal Core Spun Yarns for Functional Textiles— Production and Characterization

S.K. Chattopadhyay1, A. Yadav1, V.V. Kadam1, Bindu V.1, D.L. Upadhye1, V.D. Gotmare2 and A.K. Jeengar2 1Central Institute for Research on Cotton Technology (ICAR), Matunga, Mumbai 4000–19 India 2Veermata Jijabai Technological Institute, Matunga, Mumbai–400019 India

Abstract—In the present exploration, cotton covered jute, nylon and stainless steel core spun yarns were developed using a DREF-3000 Friction Spinning machine. In the core-sheath yarn, the cotton fibres were optimally used as sheaths by just covering and twisting them around the core components. All the yarn samples were converted into suitable technical fabrics and evaluated for functional characteristics. Fabrics made from cotton-jute core yarn were used for making upholstery fabrics with aesthetic improvement in feel, cover, color and design. Since the cost of jute is much lower than cotton, the product will be cost-effective compared to 100% cotton fabric. The increased integrity and better mechanical properties of cotton-nylon core yarns were found due to a positive linear relation between the core content and the yarn breaking tenacity further reinforced by the wrapping sheath fibres. The interface produced by the cotton sheath helped anchoring the fabric with various rubber matrices without the need of any chemical adhesive treatment. The composite thus produced resulted in an optimum peel adhesion strength of 3.11 kN/m between the rubber and the fabric, and is suitable for application in beltings. The cotton-stainless steel core yarn was used to prepare flexible shielding fabrics for protection from harmful electromagnetic waves. It was found that the shielding efficiency of the fabrics could be tailored by the fabric design, and the developed shields could mitigate electromagnetic waves to the extent of 55%.

INTRODUCTION Blending natural and man-made staple fibres is well-known, and in vogue in the yarn spinning industry. The objectives of blending of two or more staple fibres are to improve functional and aesthetic quality of textiles, processing performance and economy of production. However, blending has a major limitation - continuous man-made filament cannot be processed with staple fibres. Therefore, blending techniques are mainly restricted to producing apparel textiles rather than technical textiles. Technical textiles are used for their technical performance and functional properties mostly by other user industry. It has a vast potential to grow and excel in a developing economy like India. It has shown a healthy growth of 18% from 2001 to 2008. The current technical textile consumption in India is estimated at Rs. 41,756 crores, and is expected to grow at the rate of 6-8% (without the Government intervention), but 12-15% with stimulus from the Government (Ministry of Textiles, 2010). Therefore, the thrust is on to develop high- tech and hybrid yarns for application in the manufacture of technical textiles. The Friction spinning, a fairly new technology in the domain of yarn manufacture has asserted itself as one of the most important system in technical yarn development. In the friction spinning, the fibers from the sliver after individualization are deposited by an air current into the gap between the cylinders (Brockmans 1984; Lord and Rust 1990, 1991) rotating in the same direction, wherein either one or both the friction drums are perforated having an inside suction to restrain the deposited fibers, and consolidate them (Lord et al. 1987; Karnon 1986; Salhotra et al. 1995). The DREF friction spinning technology also produces core-spun multicomponent yarns by using filaments covered by staple fibre as a sheath (Fehrer, 1987, 1989). The main aim of using core-spun yarns is to take the advantage of different properties of core and sheath components. While the core improves the yarn strength and machine productivity, the sheath fibers add to physical properties of the surface and impart softness, bulkiness and an appearance similar to staple yarns. 478 World Cotton Research Conference on Technologies for Prosperity

PRESENT STUDY A DREF-3000 friction spinning machine has been used to produce core-spun yarns. In this machine, first the core part is false-twisted by the torque generated by the rotating friction drums, and then staple fibres are deposited on it to make a sheath that covers the core. On emerging from the twisting zone, the false- twist of the core is removed and only sheath fibres get real twisted in the reverse direction. The resultant yarns have the character of an almost twistless core and helically wound sheath fibres of varying helix angles. In the present study, the core and sheath materials have been chosen looking into predetermined end-uses. Three different core yarns were produced, viz: cotton-jute, cotton-nylon and cotton-stainless steel. The staple cotton fibre used as sheath just about covers the core part. Such optimal use of cotton as sheath in a core yarn will limit the use of cotton in the yarn. This implies that, if the core fibre is cheaper than cotton, like in cotton-jute core yarn, the resultant product will be cost-effective compared to those made from 100% cotton yarns. All the yarn samples so developed in the study were converted into suitable technical fabrics and evaluated for their functional properties. A fabric made from cotton-jute core yarn was used for making dyed upholstery fabrics. The cotton-nylon core yarn was used for preparing matrices for rubber composites, the cotton-stainless steel core yarn was converted into flexible shieldings for protection against harmful electromagnetic waves.

MATERIALS AND METHODS On the DREF-3000 machine, the spinning and carding drum speeds were kept at 3000 and 5000 rpm respectively. The yarn delivery speed was 150 m/min for jute and nylon core yarns, but 120 m/min for stainless steel core yarn.

Cotton-jute Core Spun Yarn and Fabric The cotton used for the sheath of the yarn had 2.5% span length of 32.5 mm, uniformity ratio of 0.54, micronaire of 3.5, bundle strength (3.2 mm gauge) of 25.5 g/tex and breaking elongation of 5%. It was converted into a second drawn sliver of 0.18 hank (3.3 ktex), and two of the same were used simultaneously on the DREF machine. The jute yarn was of 4.8 pounds (166 tex), and made from jute fibres with fineness of 1.89 tex and bundle strength, 26.6 g/tex. A 2s Ne (295.3 tex) DREF-yarn was spun with a core to sheath ratio of 67:33. The same was converted into an upholstery fabric of plain weave with 12 ends and picks per inch (4.7 per cm), and of fabric weight of 298 g/m2 (GSM). The grey fabric was subsequently scoured, bleached, dyed with reactive dyes and softened by exhaust finishing method.

Cotton-nylon Core Spun Yarn and Fabric For production of cotton-nylon core yarn, a nylon 6 multifilament of 420 Denier, 48 monofilaments and 0 twist, with a breaking strength of 3.08 kgf and hot air shrinkage of 4.8% (at 180ºC for 15 min) was used in the core. Four cotton slivers of 0.12 hank (4.9 ktex) each were fed to the machine to supply the sheath fibres. DREF-yarns of 1.5s and 2s Ne (393.7 and 295.3 tex) were prepared by using different core to sheath ratio, viz.,12:88, 24:76, 36:64 and 48:52. This was to find out the effect of cotton sheath on the mechanical properties of the DREF-yarn. Another yarn sample of 1s Ne (590.6 tex) with core to sheath ratio of 77:23 was spun in enough quantity to convert it into a fabric of 480 GSM with mockleno weave on a sample loom. The fabric was used as matrices in single and double layers with different rubber compositions to make textile-rubber composite samples of 4.5 and 7 mm thickness respectively.

Cotton-stainless Steel Core Spun Yarn and Fabric A steel wire of 0.145 mm diameter along with 840 denier polypropylene multifilament consisting of 84 monofilaments was used in the yarn core. Cotton fibres separated from four second drawn sliver with a hank of 0.25 (2.3 ktex) each were used to supply fibres for the sheath to cover the core, and produce a core-yarn of 3s Ne (196 tex). The core to sheath ratio was 40:60. The yarn was used as a weft in a warp sett prepared from a 20s Ne (29.5 tex) normal cotton yarn. Fabric samples of plain, 2/2 twill and honeycomb weave constructions were woven with a cover factor of 20 to 22. Repeat samples were also produced for confirmation of the results. Optimal Cotton Covered Jute, Nylon and Metal Core Spun Yarns for Functional Textiles 479

Measurement of Yarn Properties The yarn diameter and the surface of DREF-yarns were studied by using an Image Analyzer (Model: MVIG 2005) and a Scanning Electron Microscope (SEM) (Model: Philips XL-30). The denier of the nylon yarn was measured according to ASTM D 1059-97 test method. The tenssile properties of yarns were measured on a Star Universal Tensile Testing Machine (UTM) following the standard testing conditions according to ASTM D 2256-02, and the shrinkage percentage of nylon according to ASTM D 2259-96. The testing speed and gauge length of testing on the UTM were 300 mm/min and 500 mm respectively. Measurement of Fabric Properties The tensile strength of the fabric was measured according to ASTM D 5035-95 with a strip size of 7.5 x 5 cm ravelled strips. Since the fabrics were to be used for technical application rather than apparels, tensile strength with wide-width method was also measured according to ASTM D 4595-95 standard. The trapezoid tear strength and the index puncture strength were measured as per ASTM D 4533-91 and ASTM D 4833-88 respectively. The IS 6490-71 standard test method was used to determine the flexural rigidity. Measurement of Fabric to Rubber Adhesion Strength The peel strength, i.e., the fabric to rubber adhesion (bond) strength was determined according to ASTM D-1876. An Instron Universal Testing Machine was calibrated and the crosshead speed was set at 50 mm/min. The strap, with a test specimen size of (25 X 100 mm) was fixed between the two grips of the UTM. As the machine started the test piece reached ‘T’ shape, and the force (kN/m) required to peel the specimen was recorded. Measurement of Electro-Magnetic Shielding Effectiveness (EMSE) Any barrier between an emitter and a receiver that decreases the strength of an electromagnetic field acts as a shield. The Electro-Magnetic Shielding Effectiveness (EMSE) is a measure that expresses quantitatively how much an electromagnetic field is attenuated because of the barrier, and is expressed as follows:

Fig. 1: EMSE Measurement Set-up

EMSE=10 log10 (Pout/Pin) (1)

EMSE in the unit of decibel (dB) is expressed as a power ratio, where Pout is the output power (watts) and Pin is the input power (watts). 480 World Cotton Research Conference on Technologies for Prosperity

An RF Network Analyzer (VNA) with a 50 Ω impedence, was used to generate EM waves in the frequency range of 300 KHZ to 3 GHZ and passed through an anechoie circular co-axial fabric holder fabricated in accordance to ASTM standard D4935-99 (ASTM, 1999). It simulates the far field shielding behaviour. The measuring set-up is shown in Figure 1. The purpose of the test is to measure quantitatively the insertion loss that results from introduction of the fabric as a shield, when the electromagnetic plane wave is applied as normal to the surface of the material. The power from the transmitter is coupled to a receiver, first without any barrier to set up a reference level, and then with the fabric shield introduced using a two-port network (Fig. 2). The ratio of the two powers gives the insertion loss (IL) from which EMSE was calculated using formula (1).

Fig. 2: Two-Port Network

RESULTS AND DISCUSSION

Cotton-jute Core Spun Yarn and Fabric The properties of the parent jute yarn vis-à-vis the cotton jute core yarn are presented in Table 1. The DREF-yarn diameter was found to increase by 64% compared to that of the parent jute yarn. The core to sheath ratio of 67:33 was verified by pulling out the sheath fibres from the core. The tenacity of DREF spun core yarn was found to reduce by 49.6%, while the breaking elongation increased by 17% compared to the parent 4.8 lbs jute yarn. This is due to unopening of the true twist in the parent jute yarn by the false-twist during friction spinning. Once out of the twisting zone, the true twist tends to return to its original state, but get partially blocked by the just laid sheath fibres. The observation of lower tenacity in cotton-jute core DREF-yarns agrees with our earlier finding (Chattopadhyay et al, 2009). The tenacity- elongation curves of the parent jute and cotton-jute core yarns from multiple spinning are shown in Figure 3.

TABLE 1: YARN PROPERTIES OF JUTE AND COTTON-JUTE YARN Sr. No. Test Parameter Jute yarn Cotton–jute Core Yarn 1 Yarn diameter (mm) 0.7 1.1 2 Yarn size (tex) 15.9 32.4 3 Breaking load (kgf) 1.51 (22.9) 1.52 (20.8) 4 Breaking elongation (%) 1.41 (16.5) 1.65 (18.1) 5 Tenacity (gm/tex) 94.9 47.0 (Figures in parenthesis indicate CV %.)

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Fig. 3: Tenacity-elongation Curve for Jute and Cotton-jute Yarn The fabric made from cotton-jute core yarn was scoured, bleached and subsequently dyed with reactive dyes using optimum recipes as determined by initial trials. First, the fabric was scoured and bleached at a temperature of 98°C for 45 minutes in a bath with 0.75% scouring agent, 1% desizing agent, 3% hydrogen peroxide, 0.3% peroxide stabilizer and 2.5% caustic soda on the weight of the fabric. The material to liquor ratio was 1:10. Next, the fabric was dyed with reactive dyes (Turquoise blue-21, Orange-3R and Red-5B) with a 2% shade depth. The fabric was finally softened by exhaust finishing at room temperature for 20 minutes with material to liquor ratio of 1:10. It has been found that the dyeing was uniform. Further, the lightfastness for cotton-jute fabric was found qualitatively better than that of the jute fabric. The inherent problem associated with jute fibres e.g., colour fading and yellowing during long storage could be masked by the cotton sheath. As jute yarn remained in tthe core covered with cotton, it has little or no chance to be exposed to direct sunlight.

Cotton-nylon Core Spun Yarn and Fabric

TABLE 2: TENSILE PROPERTIES OF DREF-3000 YARNS (1.5SNE) Multifilament Core Core Breaking Core: Yarn Yarn Breaking Yarn Work of Core Size Strength Elongation Sheath Breaking Elongation (%) Tenacity Rupture (Denier) (Kgf) (%) Ratio Strength (g/tex) (g.mm) X 105 (kgf) 420 2.6 18.7 12:88 5.5 19.0 14.0 2.6 840 5.7 18.9 24:76 7.9 23.6 20.0 4.6 1260 8.8 18.5 36:64 10.6 24.0 27.0 6.4 1680 10.7 20.0 48:52 13.1 25.3 35.6 8.7 From the analysis of data on the mechanical properties of friction spun yarns, such as yarn breaking strength, tenacity and work of rupture, it can be said that these parameters increase with increase in core denier (Table 2 and 3). The relationship between the nylon multifilament denier and the strength of two yarns, namely 1.5s and 2s Ne was found to be linear with high correlation-coefficient of 0.99 at a significance of 0.01% (P<0.001) (Fig. 4).

TABLE 3: TENSILE PROPERTIES OF DREF-3000 YARNS (2S NE) Multifilament Core Core Breaking Core: Yarn Yarn Breaking Yarn Work of Core Size Strength Elongation Sheath Breaking Elongation (%) Tenacity Rupture (Denier) (Kgf) (%) Ratio Strength (g/tex) (g.mm) X 105 (kgf) 420 2.6 18.7 12:88 4.4 19.5 14.9 1.7 840 5.7 18.9 24:76 7.2 22.1 24.2 3.9 1260 8.8 18.5 36:64 9.8 25.0 33.1 6.1 1680 10.7 20.0 48:52 11.9 24.1 40.6 7.2 482 World Cotton Research Conference on Technologies for Prosperity

Fig. 4: Relation between Yarn Core Size (Denier) and Breaking Strength Since, the strength curves of DREF-yarns follow the similar linear trend as that of the parent core- filament (plotted in the same figure), it can be inferred the strength of DREF-spun core yarn is mainly dependent on the strength of core filament yarn. However, DREF-yarn strength is also found to be higher by 11-110% compared to the parent nylon filament. It implies the sheath cotton fibres, which are wrapped crosswise over the longitudinally laid multifilaments [compare (a) and (b) in Fig. 5], are providing transverse force that binds the individual filaments and arrest their slippage during the axial loading of the yarn. The same could be corroborated from the load versus displacement plots for both the parent multifilament as well as the DREF-yarns (Fig. 6). Whereas the breakage for the multifilament yarn is found spasmodic, and therefore, associated with fibre slippage, the breaks for DREF-yarns are catastrophic in nature with nil or reduced fibre slippage. This shows improved struuctural integrity of such yarns spun on the friction spinning machine.

(a) (b) Fig. 5. a: Nylon Core Multifilament b) Cotton-nylon Core Spun Yarn

Optimal Cotton Covered Jute, Nylon and Metal Core Spun Yarns for Functional Textiles 483

(a) (b) Fig. 6. Load vs. Displacement Plot of (a) Parent Multifilament and (b) DREF-yarns The breaking elongation of DREF-yarn was found higher than the parent multifilament by 20%, which is also assigned to increased integrity of DREF-yarn caused by wrapping of sheath fibres around the core (Fig. 7). Finally, the work of rupture, that is, the energy to break a core spun DREF-yarn was found to increase with the core content at a significance of 0.01% (p<0.001) (Table 2 & 3).

Fig. 7: Relation between Yarn Core Size (Denier) and Breaking Elongation The 1s Ne (590.6 tex) produced cotton-nylon core yarn with core to sheath ratio of 77:23, had the breaking strength of 3.1 kgf, elongation of 22.5% and tenacity of 39.4 g/tex. It was woven into a mockleno fabric with 13 ends and 20 picks per inch (5.1 X 7.9 per cm) on a sample loom. The GSM of the fabric was 480. The mechanical properties of the fabric (Table 4) were found satisfactory to use the substrate as reinforcement for belting fabric. For the same, the fabric sample was composited with various rubbers, for example, natural, polychloroprene and ethylene-propylene (EPDM). The peel strength between the fabric and various types of rubbers for both warp and weft ways has been presented in Table 5.

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TABLE 4: FABRIC PROPERTIES OF COTTON-NYLON CORE SPUN YARN Sr. No. Test Parameter Value 1 Tensile strength (Ravelled strip) a. Breaking Strength (N) Warp 1931 Weft 1905 b. Elongation at break (%) Warp 36.1 Weft 37.3 2 Tensile Strength (Wide width) a. Breaking Strength in kN/m Warp 39.0 Weft 36.4 b. Elongation at break (%) Warp 37.2 Weft 37.8 3 Tear Strength (Trapezoid Tear) Peak Mean Load (N) Warp 480 Weft 430 4 Index Puncture strength Resistance (N) 620 5 Flexural rigidity (mg.cm) Warp way 15471 Weft way 164

TABLE 5: PEEL STRENGTH OF FABRICS MADE FROM CORE SPUN DREF YARN IN RUBBER COMPOSITE Sample No. Type of Rubber Peel Strength (kN/m) Average Peel Strength Warp Weft (kN/m) 1 Natural rubber (NR) 2.62 3.11 2.87 2 Polychloroprene 2.32 2.16 2.24 3 Ethylene- propylene (EPDM) 2.62 3.11 2.87 Such cotton covered nylon fabric does not require extra chemical adhesive treatment, such as Resorcinol Formaldehyde Latex (RFL), which otherwise would have been necessary if the fabric was made with only nylon fibre. Apart from general chemical affinity between rubber and cotton, it appears the cotton fibres has provided more number of binding points for the rubber because of their fibrous and irregular surface. The yarn surface was viewed under scanning electron microscope (Fig. 8). The integrated yarn made from many nylon monofilaments wrapped tightly by cotton fibres with high surface irregularity was clearly visible in the cross-sectional view (Fig. 8a). The peel strength is an important parameter that decides bonding between the rubber and the textile. It is the ability of a material to resist forces that can pull it apart and separate into two parts. It was found that resultant fabric could yield an average peel bond strength of 2.87 kN/m and seems suitable for application in beltings. The cotton covered nylon core fabric yielded good peel strength with all the rubber matrices viz., natural rubber, polycholoroprene and ethylene-propylene (EPDM).

(a) (b) Fig. 8. (a) Cross-sectional and (b) Longitudinal SEM Image of Cotton-nylon Core Yarn

Optimal Cotton Covered Jute, Nylon and Metal Core Spun Yarns for Functional Textiles 485

EMSE of Fabrics Made from Stainless Steel Core Yarn Figure 9 shows the typical variation in EMSE of a woven fabric shield when subjected to different incident frequency of the electromagnetic waves, ranging from 300 kHz to 1.6 GHz. It can be seen that EMSE value optimize at a particular frequency. Table 6 presents the optimum EMSE value and its corresponding frequency for the various fabrics developed in the present study.

Fig. 9: EMSE Plot at Different Frequencies of Electromagnetic Wave It can be seen the optimum EMSE increases with increasing pick density which is mainly assigned to increase in stainless steel content per unit area of the fabric. Further, the optimum EMSE value was found to be highest for the plain weave followed by twill and honeycomb (Table 6). As plain weaves are more opaque compared to twill and honeycomb, they offer better shielding efficiency. The developed fabric shields could mitigate Very-High Frequency (VHF) to Ultra-High Frequency (UHF) bands of electromagnetic waves by 34-55%. Further research to design improved textile shield is in progress.

TABLE 6: MAXIMUM EMSE VALUES OF VARIOUS FABRIC SAMPLES Weave Type Thread Density (Warp x Weft) Per Inch (Per cm) Cover Factor Frequency (HZ) EMSE (dB) Plain 28 x 30 (11 x 11.8) 19.7 6.15 x 108 50 Plain 28 x 32 (11 x 12.6) 20.6 6.15 x 108 55 2/2 Twill 28 x 30 (11 x 11.8) 19.7 6.38 x 108 42 2/2 Twill 28 x 34 (11 x 13.4) 21.5 6.38 x 108 52 Honeycomb 28 x 34 (11 x 13.4) 21.5 7.05 x 108 34 Honeycomb 28 x 38 (11x 15) 23.3 7.05 x 108 42

CONCLUSION We have developed and characterised optimal cotton covered jute, nylon and stainless steel core yarns spun using a DREF-3000 Friction spinning machine and their technical fabrics. The following observations are made from the present exploration: • Upholstery fabric developed from cotton covered jute core yarn is of improved feel and cover, and could be coloured with reactive dyes normally like all cotton fabrics. The inherent problem associated with jute fibres like colour fading and yellowing during prolonged storage could be masked with the covering of cotton sheath fibres. • The loss of yarn tenacity with gain in elongation in cotton-jute core yarn is attributed to the detwisting of the jute yarn by the false-twist generated in friction spinning. Though true twist tends to return once out of the torque zone, it get partially blocked by the just laid sheath fibres. • In cotton covered nylon core yarn, since the nylon is zero twisted, the above phenomenon is not observed. The increased integrity and better mechanical properties of cotton-nylon core yarns are 486 World Cotton Research Conference on Technologies for Prosperity

due to the core content contributing positively, further aided by the reinforcement of surface sheath fibres that resist fibre slippage during the yarn loading. • The mockleno woven fabric made from cotton covered nylon core yarn could be bonded with different rubbers without the need of any extra chemical adhesive treatment. • The peel adhesion strength of the fabric with the rubber was found to be 3.11 KN/m, which is enough to be used as composites for belting purposes. • It is found the Electro-Magnetic Shielding Efficiency (EMSE) value for a fabric shield typically optimises at a particular frequency of the electromagnetic wave. • EMSE increases with increasing pick density of the fabric attributed mainly because of increase in the stainless steel content. It is also the highest for the plain weave, which is more opaque than similarly woven twill and honeycomb fabric shields. • The developed fabric shields could mitigate Very-High Frequency (VHF) to Ultra-High Frequency (UHF) bands of electromagnetic waves up to 55% effectiveness.

REFERENCES [1] ASTM D 4995–99 (1999)–Standard Test Method for Measuring the Electromagnetic Shielding Effectiveness of Plane Materials. [2] Brockmans, K.J. (1984) – Friction spinning analyzed–International Textile Bulletin, Yarn forming 2: 5–23. [3] Chattopadhyay, S.K., Dey S.K., and Sreenivasan S. (2009)–Composite yarns from natural fibres for production of technical textiles – International Conference on Emerging Trends in Production Processing and Utilization of Natural Fibres – 2: 338–346. [4] Fehrer, E. (1987) – Friction spinning: The state of the art – Textile Month, 9: 115–116. [5] Fehrer, E. (1989) – Latest DREF: medium counts at 300 m/min – Textile Horizons, 2(6): 20–21. [6] Karnon I. (1986) – Friction spinning – the masterspinner –, Textile Month, 3: 34–37. [7] Lord, P.R., & Rust, J.P. (1991) - Fiber assembly in friction spinning – Journal of the Textile Institute, 82: 465–478. [8] Lord, P.R., & Rust, J.P (1991) – Variations in yarn properties caused by a series of design changes in a friction spinning machine – Textile Research Journal,. 61(11): 645. [9] Lord, P.R. & Rust, J.P. (1990) – The surface of the tail in open-end friction spinning – Journal of the Textile Institute, 81(4):, 100–103. [10] Lord, P.R., Joo, C.W., & Asbizaki, T. (1987)–The mechanics of friction spinning – Journal of the Textile Institute, 78: 234–254. [11] Ministry of Textile (Govt. of India) (2010) – National Fibre Policy 2010–11. [12] Salhotra, K.R., Behra, B.K. and Joshi, V.K. (1995) – Friction spinning: pros and cons – The Indian Texitle Journal, 105(4): 86–90. 80

The Cotton Length Analysis using the Lengthcontrol

Iwona Frydrych1, Anna Pabich1 and Jerzy Andrysiak2 1Technical University of Lodz, Faculty of Material Technologies and Textile Design, Department of Clothing Technology and Textronics, Lodz, Poland 2Textile Research Institute, Lodz, Poland E-mail: [email protected]

Abstract—Lengthcontrol is a fiber length measuring device produced by Trützschler, which can quickly give information about the distribution of fiber length, the short fiber content (SFC) and the content of fiber hooks. It can also give some suggestions of changing spinning machine's parameters to optimize its work. By using this measurement system, it is possible to measure all kinds of fibers, which length is not higher than 63 mm and which are formed in a sliver from the carding, drawing or combing processes. It can be successfully used in the inter-operational control. Just after 10 minutes (the measurement duration), it gives necessary data to assess the quality of the fiber sliver and to optimize machine work. The possibility of quick adapting parameters of the machine work to the actually processing fiber length is especially important in the case of cotton fibers, which are characterized by a big variability of length characteristics. In this work, there are compared the length results of measurements made on the Lengthcontrol with results from the AFIS. Such a comparison provides us information about the quality of the measurements on the Lengthcontrol. Keywords: Lengthcontrol, cotton, fiber length, inter-operational control

INTRODUCTION Cotton, as a natural fiber, is characterised by a significant variability of parameters, especially length parameters. The reason for this is the fact that main fiber properties (length, strength, maturity) are dependent on many factors such as soil and weather conditions, irrigation method, harvesting and ginning method etc. (Frydrych I., 2005; Wakelyn P., Chaudry R, 2010). This natural differentiation causes several problems such as adjustment machine working parameters during the processing. Apart from the well known cotton parameter measurement systems such as HVI and AFIS, there is also a new one - Lengthcontrol (TC-LCT) proposed by Trützschler (Trützschler GmbH&Co, 2006). Below results obtained from the Lengthcontrol device will be analyzed in a comparison with results of the same cotton fibers from the AFIS. The comparison was done with the AFIS system results, because both of them require the sample in the sliver form. Advanced Fiber Information System (AFIS) is a well known integrated system, which is used to obtain the fiber characteristics on the basis of measurement of single fibers separated in the air stream (Frydrych I., 2005). The AFIS-L test provides detailed information regarding important fiber properties including several length parameters (mean length by number lm(n) and by weight lm(w), upper quartile length by number, 2.5 % etc.) (Frydrych I., 2005; Wakelyn P., Chaudry R, 2010). With the AFIS use, it is possible to determine the average sample length properties, and also their variation. This system is quick, purpose oriented and reproducible measuring the raw material in the sliver form in the majority of process stages in the spinning mill. It is thus possible, based on the forecasted supervisory measures and early warning information, to practically eliminate subsequent complaints with respect to the finished product (Frydrych I., Matusiak M., 2002).

LENGTHCONTROL Lengthcontrol (TC-LCT) is a new measurement device for the use in the spinning mill. The scheme of Lengthcontrol is presented in the Fig. 1, whereas its photo in Fig.2. 488 World Cotton Research Conference on Technologies for Prosperity

Fig.1: A Scheme of the Lengthcontrol (Breuer J., 2005) It is using friendly and it doesn't have any demands on the room climate. TC-LCT is designed for the measurement of all fiber slivers up to 63 mm (but especially cotton). This device is operated only by one operator, who doesn't need to have any special qualifications. The results of measurements are available just after 10 minutes. There is no time-consuming sample preparation, because the Lengthcontrol is fed by the sliver just from the card can, draw frame or combing machine. It is fully automatic and objective, the results are not influenced by the calibration or settings.

Fig. 2: A Photo of Lengthcontrol The measurement principle is based on a modified fibrograph principle. The sliver is clamped and the fiber tuft is carefully combed at both sides. An optical sensor measures the fiber mass with a reference to the distance to the clamp, so for this reason its acting principle is more similar to the HVI.

LENGTHCONTROL PARAMETERS The results from the TC-LCT measurement can be divided into two groups: I group - basic test results (Breuer J., 2005; Breuer J., 2005a): Upper length [mm] – the value is the upper length or the 2, 5 % span length of the HVI, LCT-Length [mm] – the value is roughly equal to the mean fiber length of the AFIS, The Cotton Length Analysis using the Lengthcontrol 489

Fiber hooks [%] - the value gives a measurement of fiber parallelization. The lower the value is, the less fiber hooks in the sliver are. II group – additional results and parameters (Breuer J., 2005; Breuer J., 2005a): LCT-length x hooks [mm] – this value links the information regarding hooks and length. Fibers are only really long if the length is long and the number of hooks is low, Short fiber length [mm] – this value shows that 10 % of fibers are shorter than this length, Short fiber amount [%] - this value describes the percentage ratio of short and long fibers, Short fiber content [%] - this value indicates the fiber content at 12,7 mm fiber length, Staple gradient [%] - this value describes the ratio of short and long fibers. Just after the measurement all the parameters are displayed on the screen and, moreover, a graphical representation of the fiber length gradient is also possible. The way how the Lengthcontrol shows the results is presented in Tables 1, 2.

TABLE 1: THE BASE TEST RESULTS

TABLE 2: ADDITIONAL TEST RESULTS

For the further analysis two length parameters measured by the Lengthcontrol have been chosen: upper length (which according to the producer corresponds to the 2.5 % span length value from the HVI) and LCT-length (which is comparable to the mean fiber length from the AFIS). There will be also compared short fiber content (SFC) values.

SAMPLE PREPARATION The subject of measurement were 15 American standard cottons differed by the length. Because the Lengthcontrol can be fed only by the sliver, fifteen types of fibers had to be formed in such a structure. For this purpose, Microdust and Trash Analyzer (MDTA) (presented in the Fig. 3) from the Textile Research Institute (Lodz) was used. MDTA is a device, which can provide the cotton in the sliver form and therefore, it was used for the sample preparation for the measurements on the Lengthcontrol (Frydrych I., 2005; Wakelyn P., Chaudry R, 2010).

490 World Cotton Research Conference on Technologies for Prosperity

Fig. 3: A View of the Microdust and Trash Analyzer and the Sliver (Frydrych I.,2005)

RESULTS AND THEIR ANALYSIS For the length analysis the following length parameters from the AFIS were chosen: the mean length by weight L(w), the mean length by number L(n) and two parameters from the Lengthcontrol: LCT length i Upper length. Moreover, on the basis of obtained results Rusing the PQStat software, the statistical analysis was carried out, the correlation coefficient was determined as well as its significance for the whole population (Gniotek K., Kucharska-Kot J., 2004). The obtained measurement results from the AFIS and Lengthcontrol are set in Table 3.

TABLE 3: RESULTS OF CHOSEN COTTON LENGTH PARAMETERS FROM THE LENGTHCONTROL AND AFIS Lp. AFIS Lengthcontrol L(w) [mm] L(n) [mm] Upper Length [mm] LCT Length [mm] mean S.D. mean S.D. mean S.D. mean 1 21.4 0.3 17.4 0.4 23.42 0.7 14.98 2 21.3 0.1 16.8 0.3 23.48 0.1 15.31 3 25.6 0.2 20.8 0.3 27.52 0.3 18.90 4 24.4 0.2 20.1 0.3 27.05 1.1 21.52 5 25.1 0.3 20.2 0.4 27.53 0.2 18.46 6 19.7 0.2 15.2 0.1 22.53 0.6 13.08 7 18.8 0.2 14.1 0.3 22.88 0.5 16.09 8 28.1 0.2 24.2 0.3 29.43 0.4 23.81 9 19.9 0.3 16.1 0.4 21.28 0.8 13.94 10 26.0 0.1 21.4 0.2 27.20 0.8 18.41 11 23.5 0.2 19.0 0.3 25.91 0.7 17.11 12 25.3 0.2 20.8 0.2 27.40 0.4 19.34 13 23.6 0.2 19.1 0.3 25.91 0.2 18.54 14 24.5 0.2 20.3 0.3 26.56 0.4 19.14 15 23.6 0.4 18.5 0.4 26.17 0.4 17.66 The coefficient of linear correlation for two pairs of results from both measurement systems are presented in Table 4.

TABLE 4: THE VALUES OF LINEAR CORRELATION COEFFICIENTS FOR THE CHOSEN LENGTH PAIRS OF RESULTS FROM THE AFIS AND LENGTHCONTROL Parameter from the AFIS Parameter from the LCT Correlation Coefficient L(w) Upper length 0.97 L(n) LCT length 0.88

The Cotton Length Analysis using the Lengthcontrol 491

Fig. 4: The Relationship between Parameters L(w) and Upper Length

Fig. 5: The Relationship between Parameters L(n) and LCT Length As a result of carried out test of correlation coefficient significance for the whole cotton fiber population the following values of probability were obtained: - for parameters L(w) and Upper length – p < 0.000001, - for parameters L(n) and LCT length – p = 0.000018. Comparing these values with the assumed level of test significance α=0.05, it can be stated that in both cases there exist the linear correlation between the cotton length parameters for the whole population. In Figures 4 and 5, there are presented the mentioned above relationships between appropriate fiber length parameters and the linear regression equation is given.

SHORT FIBER CONTENT Except the length parameters the AFIS and Lengthcontrol give us also information about the short fiber content (SFC). This parameter demonstrates the percentage of fibers that are shorter than 12.7 mm. The relationship between measurements made on the AFIS and Lengthcontrol is shown in Fig. 6 (Pabich A., Frydrych I., Raczyńska M., Andrysiak J., 2010). 492 World Cotton Research Conference on Technologies for Prosperity

Fig. 6: The Values of SFC Parameters from the Lengthcontrol and AFIS In Fig. 6., there is presented a graph with three sets of points related to the SFC by number and SFC by weight from the AFIS and SFC from the Lengthcontrol. There is shown that thhe SFC results from the Lengthcontrol are the most correlated with the results of SFC by number from the AFIS. In spite of some points, where the differences are seen, the majority of results is almost equal.

CONCLUSION There were compared the results of two length parameters (Upper length and LCT length) from the Lengthcontrol with appropriate L(w) and L(n) from the AFIS, which seemed to be the most similar to the parameters from the Lengthcontrol. Additionaly, the SFC parameters from the Lengthcontrol and AFIS have been compared. On the basis of measurement and statistical result analysis it can be stated that there is a strong linear correlation between L(w) from the AFIS and Upper length from the Lengthcontrol. Presented results show that a new system of measuring the fiber length – Lengthcontrol can be a competitive method for the older ones, especially in the case of interoperation control, where the half- product of machines such as the card, draw frame or combing machine is the sliver, there is no need to make an additional operation to prepare special samples for the measurement of fiber length parameters.

ACKNOWLEDGEMENT This work is (partially) supported by Structural Founds in the frame of the project titled „Development of research infrastructure of innovative techniques and technologies of textile clothing industry” CLO – 2IN – TEX, financed by Operational Programme Innovative Economy, 2007-2013, Action 2.1.

REFERENCES [1] Breuer J., (2005), Lengthcontrol LCT – Far more than just a fiber length measuring device, Trützschler Sales Info. [2] Breuer J., (2005)a, Lengthcontrol LCT – The decisive step towards quality assurance and quality optimization, Trützschler Sales Info. [3] Frydrych I., Matusiak M, Trends of AFIS Application in Research and Industry, Fibres &Textiles for Eastern Europe vol. 10 Nr 3(39), 2002. [4] Frydrych I., (2005), Cotton – assessment systems and methods. Editor of the Technical University of Lodz, Lodz (in Polish). [5] Gniotek K.. Kucharska-Kot J. (2004), Commensurability of Measuring Instruments for Textile Science and Practice, FIBERS & TEXTILES in Eastern Europe, Vol. 12. No. 2 (46) [6] Pabich A., Frydrych I., Raczyńska M., Andrysiak J., (2010). The Lengthcontrol – a comparative analysis of cotton length parameters. TEXSCI 2010. Liberec. [7] Trützschler GmbH & Co. KG, Moenchengladbach (2006), TC-LCT fiber length measuring device, Operating instructions, Germany. [8] Wakelyn P.J., Chaudry M.R. (2010), Cotton: Technology for the 21st Century, ICAC. 81

An Innovative Bio-chemical Approach for Low Energy and Less Polluting Scouring of Cotton Textiles

P.V. Varadarajan, R.H. Balsubramanya, Nayana D. Nachane, Sheela Raj and R.R. Mahangade Central Institute for Research on Cotton Technology, Mumbai

Abstract—The Indian textile scene is dominated by small and medium scale processing units. The scenario has not undergone drastic changes even under the new economic order as witnessed in other sectors. The main requirement of the Wet processing sector is low energy and less polluting processing technique. In this direction, CIRCOT has successfully initiated and developed a new bio-chemical scouring technique for cotton goods. The new method is low energy and least polluting one. The newly developed method employs a mixed microflora developed and maintained at CIRCOT. Under this treatment the fabric is subjected to anaerobic treatment at room temperature. In the above study, 100% cotton woven fabric of low weight was employed. The fabric was subjected to anaerobic treatment at room temperature for various length of time followed by peroxide bleach and dyed with hot brand reactive dye. The fabric samples at different stages were evaluated for weight loss, whiteness index, C.V. of whiteness index, absorbency, viscosity, colour strength, fabric strength and elongation at break. All the treatments were compared with conventionally kiered and bleached fabric as control. To determine the usefulness of the fabric for apparel applications, impact of the bio-scouring process on the low stress mechanical characteristics were also investigated. The KES-FB system was employed and properties such as Tensile, Bending, Compression, Shear, Surface friction and Roughness were evaluated. Bio-scoured fabric showed better extensibility as compared to the conventional treatment. No change was observed in Bending rigidity on bioscouring treatment. An increase in fabric surface smoothness was indicated in the case of bioscoured fabric. Primary handvalues displayed an improvement in the case of bioscoured fabric as against the conventionally scoured fabric. The results of the extensive studies show that the properties of the treated fabric are on par with the conventionally processed ones. It is further observed that the colour value of the treated and dyed samples are in fact higher than the conventionally processed ones. The above process can be easily coupled to existing Hand Processing Units leading to considerable reduction of pollution load along with appreciable saving of energy.

INTRODUCTION Scouring is an important pretreatment operation in the processing of cotton and cotton blended materials.The main objective of the above operation is to remove the non-cellulosic constituents of cotton fibre which make the fibre non-absorbent posing serious technical problems in the subsequent wet processing operations. In fact, the scouring operation determines the ultimate quality of the finished product. The scouring operation consists of treating the cotton goods with 1-2% of NaOH solution at high pressure and temperature for 4-5 hours. The above operation is not only energy intensive but also leads to environmental pollution. It is estimated that scouring operation consumes about 1% of the total water used, contributes 54% of the total BOD and is responsible for 10-25% of the total pollution load of the entire textile processing operations. It is pertinent to observe here that in view of the ever widening gap between the demand and supply position of energy, serious effects are on, in almost every field of activity either to cut down the un-necessary expenditure of energy or to adopt a low energy process. In the light of the above observations it is not surprising that a number of studies1 have been initiated over the years to make scouring operation less energy intensive and more effective one. A survey of the literature shows that but for the development of a number of chemical additives2-6, and use of certain pure 494 World Cotton Research Conference on Technologies for Prosperity

enzymes7-9, the basic operation of scouring remains essentially energy intensive and polluting in nature. The present study therefore attempts a novel technique to produce a mixture of enzymes in-situ to make the scouring operation less polluting and less energy intensive. The anaerobic technique developed at CIRCOT10 for the degradation of the cellulosic waste is employed in the present study to carry out scouring operations on 100% cotton fabric. Initially, quality and characteristics of apparel fabrics were evaluated by touching and feeling by hand, leading to a subjective assessment of them. Around 1972, Kawabata, Niwa and their colleagues15-16 developed an objective evaluation system based on the precise measurements of certain mechanical and surface properties. The instruments used for these measurements was known as KES-FB system, wherein instead of feeling fabric by hand, this instrument system touch fabrics to measure their mechanical properties and surface properties under low load conditions. The mechanical property parameters are converted to assess the Handle Value of the fabric. These elementary fabric mechanical properties are generally believed to relate to important fabric characteristics such as drape, handle, tailorability, wrinkling, creasing, shape-retention properties and other aesthetic characteristics. The present study involves scouring through mixed microbial culture created in-situ followed by alkaline treatment and the impact of such novel treatment on the low stress mechanical properties of bioscoured cotton have not been studied till now.

MATERIALS AND METHODS In the above study 100% cotton woven fabric of low weight (78g/sqm) was employed. The fabric was in grey state. The required quantity of fabrics was subjected to anaerobic digestion for 10h and 20 h respectively. Microbial consortium was used to treat the fabric. The consortium comprised both aerobic and anaerobic-types. Species belonging to Bacillus and Micrococcus sp. from Gram positive group and Beijerinckia, Pseudomonas, Xanthomonas and Flavobacterium were from Gram negative group. Aspergillus, Penicillium and Mucor were from fungi and Streptomyces was the alone Actinomycete. All these were from the aerobic ones surviving under anaerobic conditions. As and when the system was disturbed, these were acting as scavengers of oxygen and setting anaerobiosis. Among anaerobic groups, species of Methanomicrobium, Desulfoto-maculum, Clostridium, Chlorobium, Ectothiorhodo-spire, Thiodictyon and Rhodospirilhim were predominant. The presence of Chlorella as green alga and Anacystis as blue green alga was found to grow profusely under anaerobic-conditions. One species of protozoan belonging to the genus Monocercononas was also present The anaerobic digestion was carried out in sealed glass jar employing a 100% mixed flora developed and maintained at CIRCOT. The digestion was carried out at room temperature of approximately 32°C. At the end of the digestion period the samples were boiled with 0.5% and 1% NaOH solutions (owf) for 15 minutes, washed and air dried. The above treated samples were bleached with peroxide employing a M:L ratio 1:20 with 3g/l peroxide,1.5 g/l Na-silicate and 1g/l NaOH (owf) at boil maintaining the pH at 10 to 11 for one hour. The bleached samples were dyed with hot brand reactive dye. One set of grey sample was subjected to conventional kiering consisting of boiling with 1% NaOH under 15lh/inch squire pressure for 4 hours followed by bleaching and dyeing. The fabric samples at different stages were evaluated11-13for weight loss, wax content.whiteness index, uniformity of whiteness index, water absorbency, viscosity, colour strength, fabric strength and elongation at break. All the treatments were compared with conventionally kiered and bleached sample as control. The reflectance measurements of all the samples were carried out using Jaypak - 4802 computerized colour matching system. From the reflectance values, colour strength, expressed as K/S values, were calculated at the wavelength of maximum absorption (X max) using the Kubelka - Munk equation. The low stress mechanical properties were measured on the Kawabata Fabric evaluation System (KES-FB) under standard conditions. The fabrics were tested on the five modules of the KES-FB system viz KES-F1 Tensile and Shear Tester, KES-FB2 Pure Bending Tester, KES-FB3 Compression Tester and KES-FB4 Surface Tester to measure the Tensile and Shear, Bending, Compression and Surface properties respectively. The fabric hand value was evaluated using the Kawabata System of equations. An Innovative Bio-chemical Approach for Low Energy and Less Polluting Scouring of Cotton Textiles 495

RESULTS AND DISCUSSION Tables l and 2 depict the comparative behavior of the fabric samples subjected to conventional and anaerobic digestion for 10h and 20h, under different experimental conditions in respect of weight loss, whiteness index, fabric strength and elongation, fluidity and, colour strength. It can be seen from the above Tables that the anaerobic digestion carried out for 10 h under different experimental conditions have in general shown lower weight loss as compared to the conventional kiering. Similar trend is observed in respect of the bleached samples too. Table 2 which depicts the trend of weight loss under 20 h anaerobic digestion also shows a similar behavior but the weight loss is higher than those of the samples subjected to 10 h digestion. It is interesting to observe an increasing trend in the whiteness index of the anaerobically kiered sample followed by boiling with 0.5% and 1% NaOH (owf) respectively. The treatment of anaerobic digestion followed by boiling with 1% NaOH confers the same whiteness index as that of the conventionally kiered ones. In respect of the samples anaerobically treated followed by alkali boiling and bleaching clearly show that with the increase in the concentration of NaOH used for boiling, the whiteness index also increases. The whiteness index of the anaerobically treated boiled with 1% NaOH and bleached samples almost compare with those of the conventionally kiered and bleached samples. Similar trend is witnessed in the case of samples subjected to 20h anaerobic digestion as depicted in Table 2. The study also showed that the extent of removal of wax through anaerobic digestion followed by 0.5% and 1% open alkali boil is as efficient as that achieved through conventional kier boil. In fact the wax content of the sample subjected to 10 h anaerobic treatment and 1 % alkali boil followed by bleaching was lesser than that of the conventionally kiered and bleached fabric. The water absorbency of the fabric is an important functional parameter. It can be seen from Table 1 that the fabric subjected to only anaerobic treatment for 10h is not absorbent but when the anaerobic treatment followed by alkali boiling makes the fabric absorbent. It is further noted that an increase in NaOH concentration employed for boiling after anaerobic treatment does not appear to have any influence on water absorbancy property. The overall results of absorbancy as shown in Table 2 indicates that the samples become more absorbent with increase in the duration of digestion. Table 1 presents an interesting picture of the behaviour of samples in respect of strength and elongation properties. In general it is observed that both the conventional and the anaerobic kiering treatments lower the fabric strength. It is evident from the Table 1 that the samples subjected to anaerobic treatment followed by alkali boiling possess an improved strength retention as compared to the conventionally kiered samples. Similar trend is observed in the case of the samples subjected to 20h anaerobic treatment as depicted in Table 2. It can also be inferred that the longer duration of anaerobic treatment leads to a lower strength retention. It is further noted that the strength reduction trend of the bleached samples differ between the treated and control samples. It is seen that the extent of strength reduction of anaerobically treated and bleached samples is much lower than conventionally kiered and bleached samples. This could possibly be attributed to the lower degradation of anaerobically treated samples as compared to the conventionally kiered samples as reflected in the fluidity values shown in the Table 1 and 2. This could possibly be attributed to the reported fibrillar agglomarisation in the case of cotton fibre samples subjected to anaerobic treatment as observed by Bhatawdekar et.al14 The ends and picks values of the treated samples indicate that a possible fabric structural differences have taken place similar to that noticed during fabric shrinkage and hence to some extent the observed higher strength retention could possibly be attributed to the changes in the ends and picks values. But the results also show that the anaerobic digestion process also appears to be less degradative as reflected in the lower fluidity values. It could therefore be safely observed that the anaerobic digestion process does confer higher strength retention as compared to the conventional kiering process. It is further noted that in all the samples whether conventionally kiered or subjected to anaerobic digestion a general strength reduction is noted subsequent to dyeing. In respect of the elongation retention, the anaerobically treated samples as shown in Table 1 show an entirely different trend to that of the conventionally kiered samples. In comparison to the conventionally kiered samples where, a general 496 World Cotton Research Conference on Technologies for Prosperity

reduction in elongation is noted,the anaerobically treated samples that are subjected to alkali boiling on the contrary show an increase in the elongation retention. Once again the observed increase in the elongation may possibly be attributed to a relatively higher shrinkage factor of the treated fabrics as compared to the conventionally kiered ones. Such anomalous behavior is not noticed in the case of samples subjected to 20h anaerobic treatment. Tables 1 and 2 also depict the whiteness index of the control and the anaerobically kiered samples. Though the whiteness index of the samples subjected to only anaerobic kiering are much lower to that of the conventionally kiered sample, the whiteness improves when the anaerobically treated samples are given an alkali boiling. It can be seen, that the whiteness index of anaerboically treated samples followed by 1 % alkali boiling is almost on par with that of the conventionally kiered samples. However, it is interesting to note that in all the cases the anaerobically treated and bleached samples show superior whiteness index values as compared to the conventionally kiered and bleached samples. It is also noted that the whiteness index of bleached samples increase when anaerobic treatment is followed by alkali boiling. In order to study the uniformity of whiteness achieved through anaerobic treatment, eight reflectance measurements were undertaken on each of the samples and the C.V. of the whiteness index was considered as a measure of the uniformity of whiteness. It can be seen from Table1 that the C.V. value of the whiteness index had shown a drop from 2.57 for conventionally kiered to 1.27 and 0.99 for the anaerobically treated alone and alkali boiled samples respectively. Though the C.V. of the sample boiled with 1% NaOH is higher still it is much lower than the conventionally kiered sample. Thus on the whole anaerobic treatment followed by alkali boiling appears to impart more uniform whiteness as compared to the conventionally kiered samples. A similar trend is observed with the bleached samples also. In order to study the response of such anaerobically treated and bleached samples to dyeing, all the samples were dyed to 2% shade employing a hot brand reactive dye. It can be seen from Table1 that the anaerobically kiered samples in general show higher K/S values as compared to the conventionally kiered samples. However,in the case of samples depicted in Table2, K/S values of treated samples are almost on par with the control. The colour characteristics of the anaerobically treated sample match with that of the conventionally kiered control sample. The L*a*b* values indicate that the anaerboically treated dyed samples have a relatively higher colour strength with a slightly higher yellowish tinge. The tensile properties of the conventionally scoured and bioscoured samples are measured using tensile tester KES-FBI. The values EMT, WT and RT of the three samples are depicted in Table 3. EMT is extensibility under a load of 500g/cm. It is a measure of fabric ability to be stretched under tensile load. Bioscoured samples B and C showed better extensibility compared to conventional kiering. The values of WT give a measure of work done during extension. WT is higher for samples B and C as compared to conventional kiering. This suggests that the bioscoured samples are easily stretchable when subjected to tensile deformation than that subjected to conventional treatment. RT is a measure of tensile resilience. This represents the recovery of the fabric from tensile deformation. Values of RT were observed to be less for bioscoured fabrics as compared to the conventionally scoured. Table3 depicts the bending properties of the conventionally scoured and bioscoured samples. The term “B” denotes the bending rigidity and “2HB” denotes the hysteresis of bending moment. The bending rigidity does not vary among the samples. Whereas, 2HB values of the bioscoured samples are lower than the conventionally scoured ones indicating lower hysteresis losses in bending deformation as compared to the conventionally kiered. In short the bioscoured ones showed better recovery from bending deformation. The compression parameters WC( compression energy),RC (compression resilience)and LC(linearity of compression )is measured using KES-FB3 Compression Tester. Conventionally kiered sample showed higher WC value indicating that the fabric is more compressable than the bioscored fabrics. Compression resilience is the percentage of the extent of recovery or regain in fabric thickness when applied force is removed. No significant difference was observed in RC values between the conventional kiered and bioscored fabrics. An Innovative Bio-chemical Approach for Low Energy and Less Polluting Scouring of Cotton Textiles 497

Surface properties of conventionally scoured and bioscoured samples are shown in Table 3.Values of MIU is a measure of the mean values of coefficient of friction between fabric surface and metallic piano modelsurface detector, whose surface is simulated to the finger surface. Sample C showed significant decrease in MIU, MMD and SMD values indicating a much smoother surface for bioscoured fabric compared to conventional kiered sample A. The increase in fabric smoothness is indicated in the value of Numeri too which is 5.93 for sample C as against 5.39 for conventional kiering. Shear tester KES-FBI was used to determine the G, 2HG and 2HG5 values of the fabric samples. These values in brief is a measure of a fabric’s ability to deform in its plane. The overall picture of Table3 which show the shear property of the samples, do not show any change in its shear property whether it is conventionally kiered or bioscoured under different conditions. The Primary Hand Values of the three samples present interesting picture. Sample C showed an improvement in fabric smoothness ( Numeri ). It also showed a marginal improvement in fabric softness and fullness ( Fukuremi ) as compared to conventional kiering. This improvement in fabric smoothness and softness resulted in a higher value for THV ( 2.89 ) for sample C as compared to the value of THV ( 2.46 ) for conventional kiering.

CONCLUSION The overall results of the above study seems to show that the anaerobic digestion followed by mild alkali boiling could offer a simple, low energy, less polluting, eco-friendly kiering technique for 100% cotton fabric. The quality of the kiered samples in terms of fabric strength, elongation whiteness index and the uniformity of the whiteness is on par with that obtained through conventional kiering process. The colour strength of treated and dyed samples is slightly higher than that of the control. In brief, the properties of the fabric subjected to biochemical technique are comparable to that obtained in conventional treatment. Impact of the bio-scouring process on the low stress mechanical characteristics such as Tensile, Bending, Shear, Surface friction and Roughness of the Bio-scoured fabrics showed better extensibility as compared to the conventional treatment. No change was observed in Bending and Shear rigidity on bioscouring treatment. An increase in fabric surface smoothness was indicated in the case of bioscoured fabric. Primary hand values displayed an improvement in the case of bioscoured fabric as against the conventionally scoured fabric. The results of the extensive studies show that the properties of the treated fabric are on par with the conventionally processed ones.

TABLE 1: FABRIC PROPERTIES OF 10 HOUR ANAEROBIC TREATMENT % % K/S Index Index Sl. No Loss% C.V. of Weight Fluidity Strength Retention Retention Whiteness Whiteness Treatment Elongation Elongation Ends/picks Absorbancy

1 0 As such - > lOmin 54.76 0.72 - 1 100 100 94/80 - 2 E0 Conv.Kier 13.2 Instant 70.81 2.57 2.2 77.4 95.5 96/90 - 3 El Con v. Kiered+B leached 13.6 Instant 85.99 1.32 6.8 73.8 89.4 99/89 - 4 E2 Conv,Kiered+Bleached+Dyed ~ Instant ~ - " 72.2 87.4 97/91 10.51 5 A0 Anaerobic Kiered 6.2 >2min 55.72 1.27 2.6 74.6 95.5 96/87 - 6 Al An.Kiered+Bleached 10.4 l-2min 79.16 0.28 3.4 89.3 124.0 98/88 - 7 A2 An. Kiered+Bleached+Dyed - Instant - - 78.2 115.4 100/87 11.77 8 A3 An.Kiered+0.5%NaOH 12.1 l-5sec 66.75 0.99 2.3 82.5 111.4 101/87 - 9 A4 An.Kiered- 12.1 l-5sec 82.60 0.61 2.9 88.9 124.0 102/90 - K).5%NaOH+Bleached 10 A5 An.Kiered+0.5%NaOH+Bleach - Instant - - - 79.4 97.2 101/90 11.35 ed+Dyed 11 A6 An.Kiered+l%NaOH boil 12.2 l-5sec 69.32 1.41 2.4 84.1 121.5 101/88 - 12 A7 An.Kiered+l%NaOH+Bleached 12.1 l-5sec 83.73 • 0.79 3.0 81.7 104.1 96/90 - 13 A8 AnKiered+1 - Instant - - - 77.0 94.7 100/90 11.24 %NaOH+Bleached+Dyed

498 World Cotton Research Conference on Technologies for Prosperity

TABLE 2: FABRIC PROPERTIES OF 20 HOUR ANAEROBIC TREATMENT % K/S Index Index Sl. No. Loss% C.V. of Weight. Fluidity Strength Retention Whiteness Whiteness Treatment Elongation Elongation Ends/ picks Absorbancy Retention %

1 0 As such - > lOmin 54.76 0.72 - 100 100 94/80 - 2 EO Conv.Kier 13.0 Instant 70.81 2.57 2.2 77.4 95.5 96/90 - 3 El Conv.Kiered+Bleached 13.6 Instant 85.99 1.32 6.8 73.8 89.4. 99/89 - 4 E2 Conv,Kiered+Bleached+D - Instant - - - 72.2 87.4 97/91 10.51 yed 5 BO Anaerobic Kiered 9.7 >2min 56.71 1.28 1.9 67.1 80.5 97/87 - 6 Bl An.Kiered+Bleached 11.0 lOsec 81.70 0.90 43 67.5 80.9 98/89 - 7 B2 An. - Instant - - - 55.6 67.9 100/88 10.27 Kiered+Bleached+Dyed 8 B3 An.Kiered+0.5%NaOH 12.4 Instant 66.42 2.04 2.1 69.4 93.1 100/90 - boil 9 B4 An.Kiered+0.5%NaOH+B 12.7 Instant 86.23 0.47 3.8 67.5 91.5 98/89 - leached 10 B5 An.Kiered+0.5%NaOH+B - Instant - - - 69.8 91.1 99/90 10.67 leached+Dy ed 11 B6 An.Kiered+l%NaOH boil 12.8 Instant 70.45 1.06 2.2 72.6 98.0 99/89 - 12 B7 An.Kiered+1 13.2 Instant 88.69 0.42 6.0 72.2 92.3 96/88 - %NaOH+Bleached 13 B8 AnKiered+1 - Instant - - - 66.7 82.9 99/90 10.38 %NaOH+Bleached+Dyed

TABLE 3: LOW STRESS MECHANICAL PROPERTIES OF TREATED SAMPLES Sr. No. Properties Sample A Sample B Sample C 1 Tensile Property EMT % 9.97 11.44 10.92 WT (g.cm/cm2) 17.96 19.28 19.31 RT % 26.87 24.74 24.18 2 Bending Property B(gf cm/cm) 0.021 0.020 0.020 2HB (gf cm/cm) 0.025 0.020 0.020 3 Surface Property MIU 0.115 0.112 0.095 NMD 0.028 0.029 0.023 SMD( micron) 7.174 7.401 4.781 4 Shear Property G (g/cm.deg) 0.56 0.55 0.56 2HG (g/cm) 1.59 1.66 1.59 2HG5(g/cm) 2.54 2.58 2.53 5 Compression Property LC 0.387 0.232 0.254 WC (g.cm/cm2 ) 0.293 0.217 0.231 RC % 56.65 52.20 53.27 T (mm) 0.558 0.646 0.656 A - Conventially kiered sample B – Anaerobic scouring and 0.5 % NaOH boil C - Anaerobic scouring and 1.0 % NaOH boil

REFERENCES [1] Harmaker, S.R.- Colourage Annual 1998, p.18. [2] Sanakari, V.D., Text Dyers & Printers, May 11, 1983. [3] Burkitt, F.H. Am. Dyest. Rep. March 1978 p.51 [4] Text. Dyers & Printers.May 1983. [5] Meyer Jim. Textile Horizon, April 1983 [6] Garrett, C.,J. Soc. Chem.& Col. 71,1955, p.83O [7] Etters, J.N. and Annis, P.A. Am. Dyest Rep., 87, No.5, 1998, p.18. [8] Etters. J.N. -colourage Annual 1998, p.87 [9] Hardin, I.R. and Kim J.-Book of Papers AATCC International Conference and Exhibition 1998, p. 319 An Innovative Bio-chemical Approach for Low Energy and Less Polluting Scouring of Cotton Textiles 499

[10] Khandeparkar. V.G., Balasubramanya, R.H. and Shaikh, A.J. -Process for the preparation of paper grade pulp from cotton plant stalk by anaerobic digestion. Ind. Pat. No. 176891, July 1993. [11] 1.S. 2349–1963.Method for determination of wettability of cotton fabrics. [12] Handbook of Methods of Tests.,CIRCOT [13] Handbook of Methods of Tests., CIRCOT [14] Bhatawdekar, S.P. Sreenivasan, S., Balasubramanya. R.H. & Paralikar, K.M., Text Res. J., 62 (5), 290–292 (1992) [15] Kawabata,S., ”The standardization and Analysis of Hand Evaluation”, 2nd ed. The Textile Machinery Society of Japan, 1980. [16] Kawabata, S., and Niwa, Masako, Fabric Performance in clothing and Clothing Manufacture, J. Textile Inst. 80, 19–50 ( 1989) 82

The Within Bale Repeatability of Standardized InstrumentS for Testing Cotton Fiber Produced in Africa

E. Lukonge1, M. Aboe2, 4, Gourlot3, J.P. Gozé3 and E. Hublé3 1Lzardi, Mwanza, Tanzania 2Association Interprofessionnelle du Coton, Parakou, Bénin 3Cirad, UPR SCA, F–34398 Montpellier, France 3Institut d'Administration des Entreprises, Montpellier, France 4Université de Haute Alsace, LPMT-EAC 7189 CNRS-UHA, Mulhouse, France

Abstract—Fiber length, fiber strength, micronaire, uniformity, reflectance and yellowness measured on standardized instrument for testing cotton (SITC) are often used on cotton bales produced in the world for trading purposes with full respect of agreed commercial tolerances in order to limit the frequency of claims. In Africa, almost no trading on SITC data is made because we lack the study of within-bale variability of the given characteristics to deduce sampling and testing protocols insuring the respect of the same agreed commercial tolerances. We then conducted this study of the within-bale variability of fiber length and its uniformity, fiber strength, micronaire, reflectance and yellowness. We took eight samples per bale within 455 cotton bales produced in 14 African countries during two crop seasons. Our representative sample is then composed of over 3600 fiber samples which were analyzed in controlled conditions by SITC in a laboratory fully respecting the international recommendations. We then achieved an estimation of the within-bale variability of cotton fiber technological characteristics in most of the African cotton producing countries. The results indicated the variability per country, per bale in some situations and it was noted that even the gins (saw and roller) have also some effects in relation to within bale variability. Keywords: cotton, fiber, within-bale variability, sampling, testing, repeatability, classification

INTRODUCTION The issue of cotton fibre characterization is important for the productivity and quality of the products obtained during processing operations such as spinning, weaving, etc. [2]. This explains why cotton classification has been based on fiber characterization. Sasser [3] and Knowlton [4] described the steps in fiber classing and testing that have gradually impacted cotton classification and worldwide trade in cotton: the most recent, hereafter referred to as “Standardized Instruments for Testing Cotton” (SITC), combines manual and visual classing in addition to a fully automated instrument testing. SITC have been increasingly used worldwide and the International Cotton Advisory Committee (ICAC) estimates that 50% of the cotton traded in the world is classed thanks to SITC, either in addition to or instead of manual and visual classing [5]. These instruments measure Micronaire, length, length uniformity, Strength and color (Reflectance and Yellowness) at least. In Africa, almost no bale is sold with instrumental result. As the within-bale variability and the sampling and measurements procedures determine the precision of bale evaluations for those characteristics, which in turn determine the risk of discrepancies exceeding commercial tolerances and ultimately litigations, United State Department of Agriculture, Agricultural Marketing Services (USDA- AMS) periodically performs variability studies in order to warrant a limited litigation risk in their given conditions. Only one publication was found focusing on the impact of the production conditions onto the within- bale variability, however without any formal treatments for production conditions [6]. The Within Bale Repeatability of Standardized Instruments for Testing Cotton Fiber Produced in Africa 501

The assumption is that the variability of SITC measurements for any given cotton bale can differ from one ginning mill to another. Indeed, equipment used, or the ginning conditions and/or the cropping system used in the supply area of the ginning mill as well as seed-cotton management practices have impacts on fiber characterizations. This question is particularly important in developing countries, in particular in the fourteen African countries that produce cotton (Benin, Burkina Faso, Cameroun, Ivory Coast, Mali, Mozambique, Senegal, Sudan, Tanzania, Chad, Togo, Uganda, Zambia, Zimbabwe) considered in this study. In these African countries, production conditions differ considerably from prevailing conditions in the USA. The cotton farms are smaller, on average 0.6 ha [7] and the cropping system is largely manual [8]. Consequently, each cotton fiber bale includes fiber produced on a larger number of farms under different field conditions and that a higher litigation risk may arise between some cotton companies from this area and their customers. In this publication, we checked the hypothesis that the application of the USA method provides results precise enough for the trading of cotton in Africa, In the opposite case, we would develop other sampling and testing modalities in order to insure that SITC methods match both the needs of SSA producers and the agreed worldwide expectations in terms of reliability, precision and the trueness of the results. In general, the within-bale variability of fiber quality depends on the agricultural production conditions and on the equipment used in the ginning mills and is affected by four main scales: 1) scale of the cotton plant, [9] [10] where fibers from different cotton bolls vary; 2) scale of the cotton field, where cropping conditions (agronomical impacts, climate, variety, cultivation practices) may differ [11, 12]; 3) scale of the supply area of the ginning mills, as seed cotton from different farms is combined before being transported to the ginning mill [13]; and 4) scale of the ginning mill and of their equipment including the management of seed cotton [14] [15]. In this publication, the main focus was on supply area of the ginning mills and ginning equipment as the main variability sources to find the level of within bale variability of the fiber characteristics as measured by SITC for the bales produced in the African countries and the most appropriate sampling and testing procedures for African countries to respect international repeatability requirements. Since nothing has been done for African cotton, it is time for African countries to adapt the USA methodology to avoid claims according to cotton quality methods and analysis procedures Therefore, through CFC/ICAC/33 project funded by the Common Fund for Commodities and the European Union, SITC tests on samples taken from the bales in the fourteen African producing countries for the two cropping seasons were done to measure the “sampling variance” due to the operational sampling conditions and testing using a SITC. MATERIAL AND METHODS Two experiments on measurement of within-bale variability were conducted in two seasons: (2008-2009 crop season 1 and 2009-2010 crop season 2). Given the large number of the ginning mills in these African countries, we chose twenty-two situations, representative of these countries, according to their seed-cotton supply areas, their ginning equipment (roller vs saw) and the presence or absence of lint cleaners. In crop season 1, 28 situations were sampled though it was half season and 35 situations were sampled during crop season 2. Some situations remained the same in both seasons to allow us to repeat the measurement in the same situations, and others were added in the second season to extend the sample of the situations. For reasons of confidentiality, all countries and situations were encoded.

Sampling Cotton Fiber for the Characterization of Fiber Properties We assumed that seed cotton transported in different trucks came from various villages, and would thus induce different levels of variability when the seed cotton differed from one village or another. In our experiment, we assumed that eighteen 225 kg bales of fibres can be produced from every seed-cotton truck. So, to insure that each sampled bale comes from a different village, we decided to select one bale out of every 20 in each situation, 502 World Cotton Research Conference on Technologies for Prosperity

Eight samples per bale from eight different layers were collected from every sampled bale. In each situation, a total of 10 bales were sampled in crop season 1 and limited to 5 bales in crop season 2. Including all selected ginning mills, the total numbers of bales and samples collected and tested were respectively 280 bales and 2239 samples in crop season 1 and 175 bales and 1400 samples in crop season 2 (Table 1).

TABLE 1: LIST OF SITUATIONS, NUMBER OF BALES AND SAMPLES TESTED Situations Crop 1Crop 2 No. of Bales No. of Samples No. of Bales No. of Samples C1G1 10 80 5 40 C1G2 10 80 C1G3 5 40 C2G1 10 80 5 40 C2G2 10 80 C2G3 10 80 C2G4 5 40 C3G1 10 80 C3G2 10 80 5 40 C3G3 10 80 C3G4 5 40 C4G1 10 80 C4G2 5 40 C4G3 5 40 C5G1 10 80 C5G2 10 79 C5G3 10 80 5 40 C5G4 5 40 C6G1 5 40 C6G2 5 40 C6G3 5 40 C7G1 5 40 C7G2 5 40 C7G3 5 40 C8G1 5 40 C8G2 5 40 C8G3 5 40 C9G1 10 80 5 40 C9G2 10 80 5 40 C9G3 10 80 5 40 C10G1 5 40 C10G2 10 80 C10G3 10 80 C10G4 5 40 C10G5 10 80 5 40 C11G1 10 80 5 40 C11G2 10 80 5 40 C11G3 10 80 C11G4 5 40 C12G1 10 80 C12G2 10 80 5 40 C12G3 10 80 5 40 C12G4 5 40 C13G1 10 80 5 40 C14G1 10 80 C14G2 10 80 C14G3 10 80 C14G4 5 40 C14G5 5 40 C14G6 5 40 Total number of bales 280 175 Total number of samples 2239 1400 Total number of situations 28 35 In crop season 1, the collection was done at the end of the ginning season, whereas in crop season 2, the collection was done in the middle of the ginning season while, ideally, the samples should be randomly selected throughout the ginning season. The Within Bale Repeatability of Standardized Instruments for Testing Cotton Fiber Produced in Africa 503

Sample Testing The six technological characteristics recommended by the CSITC Task Force of the ICAC [5] for testing; Micronaire (Mic; Micronaire unit); Upper Half Mean Length (UHML, mm); Length Uniformity Index (UI, %); Strength (Str, g/tex = 0.981 cN/tex); Reflectance (Rd, %); Yellowness (+b, Yellowness unit) were measured. For these quantitative variables assumption: when making a measurement on one sample of a bale, two additive errors are experienced: • The sampling error: the sample mean differs from the bale mean • The measurement error: due to the re-sampling of a specimen within the sample, and to the imperfection of the instruments. One bale is the result of stacking successive layers in a continuous production process leading to the assumption that within-bale variability results essentially from differences between the layers. Then we estimated the variances of the two error components with a standard two-stage sampling method. One sample from each of the eight layers was evenly distributed in each bale to be measured twice (total of two replicates). The six technological characteristics were measured centrally in a controlled laboratory using a SITC device, USTER Technologies model HVI 1000. Each replicate was carried out according to ASTM 5867 requirements [16] with one measurement of Micronaire and two measurements of the Length/ Uniformity Index, Strength, Color Rd and Yellowness. All required precautions were taken to avoid any calibration drift or, if any drift occurred, to measure it. The reference materials used for calibration were Universal Micronaire Calibration Cottons, Universal High Volume Instrument Calibration Cotton Standards for length and Strength parameters and the colour tiles delivered by the manufacturers. The reference material was also tested for every after 16 samples, and the testing conditions were recorded. All test results were grouped together in a database for statistical analysis using R software version 2.11.1 and SAS Institute software version 9.2.

Model of Exploration of the Variances We used the following model for exploring the acquired results: result = (bale fixed effect) + (layer in the bale random effect) + (replicate or measurement effect random effect) block effect [17, 18]. The indicial of this model is as: ,, , , ,, (1) Where: Y is the response variable

mi is the mean of the bale i A is the random effect of the layer j in the bale i~ 0,

Bi, k :is the effect of the block k in the bale i

Ei, j, k is the error of measurement of the replicate k of the layer j of the bale i, residual effect linked to the replicate in the layers ~ 0, , independent from A i is 1…I bales j is 1…J layers in the bale k is 1…K replicates in each layer. The two retained random effects retained as variability sources (A and E) are assumed to be independent:

corresponds to the standard deviation of the random layer effect,

corresponds to the standard deviation of the residual effect. 504 World Cotton Research Conference on Technologies for Prosperity

Our goal is to evaluate and for each retained situation and to estimate the variance error as a function of practical sampling (J’ sampled layers in a bale) and testing conditions (K’ tests per sample) or N’ if one decides to mix cotton fibers from J’ layers to analyze them all together:

or respectively (2) The full paper exactly explaining the statistical theory of this experiment is published in Textile Research Journal [1]. (3)

DEFINITION OF THE LITIGATION RISK AND CALCULATION MODALITIES In this experiment, we made all steps necessary for evaluating the litigation risk that a given tolerance (Table 2) is exceeded for each measured characteristic.

TABLE 2: TOLERANCES USED FOR CALCULATION OF THE LITIGATION RISK [16] Characteristic Commercial tolerances Micronaire +/- 0.1 unit UHML +/- 0.508 mm UI +/- 1 % STR +/- 1.5 cN/tex Rd +/- 1 % +b (Yellowness) +/- 0.5 unit For our numerical calculations, we chose a litigation risk of 10%, and the standard deviation of the difference is the commercial tolerance divided by the quintile (100-5)% of the normal distribution = 1.65. . 1.65. The standard deviation of the mean of the bale is then: (5) ..√ Three ways of decreasing the sampling variances are • Increasing the number of replicates. Then J’=1 and K’>1. This is pertinent if the contribution of the measurement error is larger than that of the between layer error. • Increasing the number of layers. Then J’ > 1 and K’ = 1. This is pertinent if the contributions of the between layer and within layer variances are well balanced. • Increasing the number of layers and replicates that are parts of the combined sample without increasing the total number of replicates. Then J’>1 and N’=1. This is pertinent when both variances are comparable in level.. Bales from the ginning mills within the bold circle will show less than 10% litigation risk with 1 layer sampled and 1 replicate. Bales from the ginning mills within the dotted ellipses will show less than 10% litigation risk with J’ layers sampled and K’ replicates. In practice, the number of layers J’ should be limited to two as it is only easy to remove samples of fiber (cutter method) from the top and bottom outside layers of the bale. Then according to the position in this chart, one can deduce the sampling and testing protocoles to e applied in the commercial classification process.

RESULTS AND DISCUSSION From results obtained on reference materials tested in the sets of samples, we did not observe any hour effect or day of testing effect in the analysis, thus proving that external conditions did not affect the technological measurements. The Within Bale Repeatability of Standardized Instruments for Testing Cotton Fiber Produced in Africa 505

Fig. 1: Example of Relationship Linking the Standard Deviation between Layers (SigmaA) vs. within Layer Standard Deviation (SigmaE)

Exploratory Analysis of the Acquired Results The contribution of the factors ‘layer’ and ‘replicate’ differed depending on the technological characteristic concerned. To illustrate these results, we display one example of the technological characteristic (Figure 2). That shows the SigmaA vs SigmaE relationship for Micronaire where the 65 situations are illustrated by a point. Many points are included in the J’=1 and K’=1 circle and more points could be included in the J’=2 and N’=J’.K’=1 ellipse than in the J’=1 and K’=2 ellipse. We concluded that, the number of layers per bale needs to be increased in the composite testing possibility. Bales from the situations inside the bold circle showed less than 10% litigation risk with 1 layer sampled and 1 replicate. Bales from the situations inside the dotted ellipse showed less than 10% litigation risk with J’ layers sampled and KK’=1 replicate in the composite testing possibility. The two extreme situations marked with arrows are those shown in the previous box plots. In all cases, the effect of the crop season (crop season 1 or 2) and the presence or absence of lint cleaner indicated some variations among the situations. There was also a problem of differences in ginning machines where the situations with roller gins were often far from the origin of the chart, we suspect a problem of seed cotton management at the ginning mill at the time (example of the point in the right uppeer corner of the Figure 2) we took our fiber samples and the saws in those gins. In the case of one sample taken from one layer with one replicate, we observed that only certain situations ensure a litigation risk lower than 10% (those inside the limit curve in bold). When all data will be available for all characteristics, we will be able to deduce the number of samples to grab per bale and the number of tests to be performedper sample in order to respect both the agreed tolerances and the lowest litigation risk as possible. However, for some situations, it appears that both SigmaA and SigmaE values are high and that some adjustments will also be necessary in the seed- cotton management from field to gin, and of fibers from the gin stand to the pressed bale. As indicated in ‘Sample testing’, we remind that one replicate corresponds to one measurement of Micronaire and two measurements of Length/ Uniformity Index, of Strength, of Color Rd and of Yellowness. 506 World Cotton Research Conference on Technologies for Prosperity

Fig. 2: Example of Micronaire: Standard Deviations between Layers (SigmaA) vs within Layer (SigmaE) for all Available Situations

Actual Limitations of the Study • In this study, we did not consider reproducibility conditions that could appear when results are different from one classing laboratory to the next. • It will be also necessary to periodically quantify the within-bale variability for each situation in order to ensure the litigation risk for any given situation. • Finally, we did limit the litigation risk to 10% for any single bale while commercial agreements and contracts generally concern lots of several bales and the General Rules of Cotton Associations; the lot litigation risk will have to be evaluated as well.

CONCLUSION The measurement of within bale variability for six technological characteristics of cotton fibers produced in fourteen cotton producing countries in Africa was done. Technological characterizations of these samples were achieved in operating conditions that ensured the repeatability of the characterizations. Within bale variance was categorized as sampling variance on one hand and as replicate variance on the other. The goal is to propose sampling and testing procedures. Using the procedures proposed based on African conditions; Africa will be able to start the instrumental classification of their cotton fibers with a sampling and a testing procedure that respects international standards and with a low litigation risk. This could also lead to improvements of seed cotton management and limit the risk of litigation. The final aim is to give confidence in SITC results to final users in Africa as well as in any other place on Earth.

ACKNOWLEDGMENT The authors wish to thank the financial contributors who made this study possible. The study was undertaken as part of project CFC/ICAC/33 Commercial Standardization of Instrument Testing of Cotton, which was funded by the Common Fund for Commodities, an intergovernmental financial institution established within the framework of the United Nations, headquartered in Amsterdam, the The Within Bale Repeatability of Standardized Instruments for Testing Cotton Fiber Produced in Africa 507

Netherlands, and by the European Union in the framework of its "All ACP Agricultural Commodities Programme” under the sponsorship of the International Cotton Advisory Committee (ICAC) Washington (USA) and implemented by the Faserinstitut Bremen (FIBRE), Germany. The authors would like to thank the personnel of the Tanzania Bureau of Standards and Tanzania Cotton Board Dar es Salaam, Tanzania on one side and the one from CERFITEX, Ségou, Mali who performed all the fiber characterizations for the present study. Finally, the authors want thank the African Cotton Companies who allowed us to take samples in their facilities for running this experiment.

DISCLAIMER This report was prepared within the project CFC/ICAC/33. The views expressed are not necessarily shared by the Common Fund for Commodities and/or the European Commission and/or the International Cotton Advisory Committee. The designation employed and the representation of material in this report do not imply the expression of any opinion whatsoever on the part of the Common Fund for Commodities and/or the European Commission or the International Cotton Advisory Committee concerning the legal status of any country, territory, city or area or its authorities, or concerning the delineation of its frontier or boundaries.

REFERENCES [1] Aboé M, Gourlot J-P, Gozé E, Hublé P And Sinoimeri A. New Findings On Within Bale Repeatability Of Standardized Instruments For Testing Cotton Measurements On Cotton Fiber Produced In West And Central Africa. Textile Research Journal (Under Press). 2011. [2] Sasser Pe And Smith Cb. High Volume Instrument Test System A Tool For Textile Manufacturing. 1984. [3] Sasser Pe And Moore Jf. A Historical Perspective Of High Volume Instrument Developments In The U. S. Itmf-Icctm. Brême1992, P. 21–5. [4] Knowlton J. International Developments In Cotton Classification. Beltwide Cotton Conferences. New Orleans, Usa: National Cotton Council Of America, 2005, P. 2254–7. [5] Icac-Secretariat. Instrument Testing Of Cotton At The Producer Level For Trading Purposes. Washington D.C., Usa2011. [6] Thibodeaux Dp, Senter H And Cui X. Within Bale Variations Of Cotton Fiber Properties. Beltwide Cotton Conferences. Nashville, Usa: National Cotton Council Of America, 2008, P. 1542. [7] Levrat R. Culture Commerciale Et Développement Rural, L'exemple Du Coton Au Nord-Cameroun Depuis 1950. Paris2010, P.292 P. [8] Levrat R. La Culture Du Coton Dans La Zone Franc. Paris, France2010, P.264 P. [9] Davidonis Gh, Johnson A, Landivar Ja And Hood Kb. The Cotton Fiber Property Variability Continuum From Motes Through Seeds. Textile Research Journal. 1999; 69: 754–9. [10] Davidonis Gh, Johnson As And Johnson Rm. Quantification Of Within-Plant And Within-Field Yield And Fiber Variability. Crop Management. 2004; Http://Ddr.Nal.Usda.Gov/Bitstream/10113/11887/1/Ind43806179.Pdf. [11] Clouvel P, Gozé E, Sequeira R, Dusserre J And Crétenet M. Variability Of Cotton Fiber Quality. New Frontiers In Cotton Research: Proceedings - Washington: Icac, 2000. 2000. [12] Meyer V.G. And Meyer Jr. Some Sources Of Variability In Boll And Fiber Properties Of Cotton (Gossypium Hirsutum L.). Crop Science. 1970; Vol. 10: Pp. 699–702 [13] Dimitrova L. And Bozhinov M. Variability Of Cotton Fiber Properties Caused By Genotype And Some Environmental Factors. Plant Science. 1988; Vol.25: N°9: 27–34. [14] Gourlot J-P. Les Tendances Dans La Standardisation Du Coton Sur Le Marché Mondial. Rôle Et Place De La Recherche Pour Le Développement Des Filières Cotonnières En Évolution En Afrique: Actes - Montpellier: Cirad, 2000. 2000, P. 113–6. [15] Usda. Cotton Ginners Handbook. Agricultural Handbook N° 503. Washington, D.C., Usa1977, P. 110. [16] D5867 A. Standard Test Methods For Measurement Of Physical Properties Of Cotton Fibers By High Volume Instruments. In: Materials Asfta, (Ed.). Annual Book Of Astm Standards. Philadelphia, Pa (Usa) 2005, P. 886–93. [17] Saporta G. Probabilité, Analyse Des Données Et Statistique. 2è Édition Ed. 2006, P.P. 1542. [18] Philippeau G. Théorie Des Plans D'expérience, Application À L'agronomie. 1989: 205.

A Vision for Technical Textiles in this Decade

A. Subramaniam Retd-Scientist, Madupra Coats, Consultant, Coimbatore, India INTRODUCTION Technical Textiles can be defined in simple term “As Textiles any other than Apparel or Furnishing Textiles”. This could be Medical Textile, Agri, Building and Geo Textiles etc.

COTTON FABRICS Woven, Non-woven, Knitted or any other manufacture items were from immemorial days for their usage in Medical and Agricultural areas. During last 20th century, Cotton through yarn and fabrics contributed substantially to Industrial / Technical Textiles in terms of Tyre cord for tyres from Egyptian cottons and from short staple Indian cotton of 1” staple (25.4mm) to produce well known Beltings of World standards for transmission and conveyor usage and fabrics for Tents to Defense and Tarpaulin for domestic purposes. But during the later part of the last Century, Synthetic and other Man-made Glass filament gradually replaced cotton due to their superior strength and desirable qualities for Technical Textiles. Still Cotton yarn was useful to cover Synthetic for adhesion purpose with Rubber for example Cotton/Nylon Beltings for conveyor. Cotton fibre and yarn are still in use without any Physical and Chemical treatment in western countries blending with Synthetics at 3 to 5% to manufacture parts for Auto Industry of Bonnet and Doors and expected to increase further by 10% during this decade.

CONTRIBUTION BY INDIAN COTTON BREEDERS During the last century, tremendous progress had been achieved by the Indian Breeders adopting new techniques in their breeding work. As a result, new varieties of cotton, such as, Shankar 4 & 6, then Varalaxmi, all in the range of long staple contributing high productivity. Later, SUVIN the highest extra long staple of 38-40mm came into production recording very high fibre strength, better than Egyptian cotton of KARNAK and MINOFI. All these Indian variety cottons served in the Apparel Industry’s requirement very well. This writer was very much involved in consuming these varieties for Sewing Thread and high quality fabrics like Poplin, spinning 100s to 120s yarn from SUVIN.

REQUIREMENT OF TECHNICAL TEXTILES The first and foremost quality requirement is fibre strength and fibre strength alone for Technical Textiles. Count range require of Technical Textiles are from 6s, 10s, 12s, 16s and 20s count maximum and do not require long staple cotton, as they are unnecessarily for their FITNESS OF PURPOSE. Hence, this writer suggest that our Breeders should concentrate in developing a short staple cotton with a maximum staple length of 1” (25.4mm) and of short duration, preferably from Rain-fed areas with high yield. Breeders should attempt fibre strength of 25 gms/tex and above. If this can be achieved by sustained effort and thrust is given on an emergency basis during this decade, then India can be Leader in developing such short staple cotton. Formers will enthusiastically welcome such high yield varieties and get a better price, as the Industry will benefit to utilize them in High Tech areas, not only at 100% level but also in components with Synthetic fibre/filament. A Vision for Technical Textiles in this Decade 509

PRESENT WORK BY THE WRITER This writer had done some development work to prove a point that a short staple of high strength cotton recording 23-25 gms/tex instead 20 gms/tex achieved today. This is done by using the by-products of long staple cotton while it is manufactured in the yarn and spinning them to Coarser count from 6s to 20s and woven into fabric. Interesting results will be shown during the World Cotton Conference to convince the Cotton Breeders that a short staple high yield fibre can revolute with high strength fibre of 23 to 25 gms / tex to the prosperity of Formers and Industrialists of Textiles. 84

Cotton Stalk: An Additional Raw Material to Board Industry

R.M. Gurjar, P.G. Patil, A.J. Shaikh and R.H. Balasubramanya Central Institute for Research on Cotton Technology, Mumbai, India

Abstract—A supply chain model comprising collection, cleaning and chipping of cotton stalks and their transportation to board manufacturing factories has been evolved. Pilot plant trials and large scale industrial trials have been conducted for making particle board and hardboard from cotton stalk. The techno-economic feasibility of manufacturing boards from cotton stalk has been demonstrated to board industry which is now convinced about its potential. In the not-very-distant future, many particle board manufacturers are likely to start using cotton stalk as an alternative raw material in place of sugarcane bagasse and hardwood. Once the industrial use of this agrowaste picks up, the farmer would be able to earn additional income from the sale of cotton stalk to the particle board manufacturers. Growth of industrial activity, rural employment generation and conservation of forest resources are other national benefits that are bound to follow.

INTRODUCTION Environmental concerns have, in recent years stimulated researches in the exploitation of renewable resources. Such researches make better economic sense when they relate to utilization of waste materials like cotton stalk. With its vast area under cotton cultivation, India is undoubtedly the largest producer of cotton stalk among world countries and stands to benefit immensely from commercial exploitation of this putative agrowaste. Profiled in this paper is CIRCOT’s saga of R & D efforts that have revealed the economic potential of cotton plant biomass abundant in many Afro-Asian countries. King cotton rules the world of textiles despite inroads made by synthetic fibres. The economy of about 90 cotton growing counties is greatly influenced by cotton. Cultivated in over 30 million ha, the annual world cotton production is about 22 million tonnes constituting 36% of the total fibre production and consumption. In recent years, India has emerged as the second largest producer of cotton next to China. The cotton production in 2009-10 in India stands at 5.1 million tonnes as against China’s 6.8 million tonnes. Other major producers are USA, Pakistan, Brazil, Uzbekistan, Turkey, Australia, Turkmenistan, Greece, Syria and Egypt. In area under cotton cultivation, India tops the world list (10.1 Mha) with China (5.4 Mha) and USA (3.1 Mha) closely following. In productivity, however, India lags behind most other countries though in recent years, there has been substantial improvement.

DISTRIBUTION OF COTTON IN INDIA

TABLE 1: COTTON CROP IN DIFFERENT STATES IN INDIA (2010-11) State Production of Cotton (In Lakh Bales) Area (Million Ha) 1 Gujarat 90.00 2.422 2 Maharashtra 62.00 3.194 3 Andhra Pradesh 53.00 1.138 4 Punjab 17.50 0.604 5 Haryana 14.00 0.483 6 Madhya Pradesh 18.00 0.630 7 Karnataka 9.00 0.402 8 Rajasthan 7.50 0.339 Table 1 (Contd.)… Cotton Stalk: An Additional Raw Material to Board Industry 511

…Table 1 Contd. 9 Tamil Nadu 5.00 0.119 10 Orissa 1.50 0.050 11 North 39.00 1.426 12 Central 170.00 6.246 13 Southern Region 67.00 1.659 14 Others 0.50 0.058 15 Loose 12.00 Total 290.00 9.436 Two leading cotton growing States in India are Gujarat and Maharashtra which respectively account for 22% and 32% of total area under cotton in the country (Table 1). The average yield is much higher in Gujarat than in Maharashtra on account of better irrigation in the former. These two States together contribute over 50% of India’s cotton crop.

CROPPING SEASON In the northern States of Punjab, Haryana and Rajasthan which are largely irrigated, cotton is harvested in the two months of October & November. Farmers in these areas cut away cotton plants even if some green bolls are still left, so as to clear the land early for the ensuing wheat crop. Stalks are removed in about a month’s time. In other regions, which are mostly rainfed, harvesting of cotton takes place from October to February. Cotton stalks are uprooted from around February–March and the process goes on till May-June since there is no pressure to vacate the field for any other crop.

LOW INCOME FROM COTTON FARMING Relatively low yield in rainfed areas has rendered cotton farming somewhat unremunerative in India. Most farmers are unable to make a living out of cotton cultivation. Ways and means to increase the returns from cotton farming, therefore, need to be explored.

RESEARCH ON BY-PRODUCT UTILISATION The diverse products available from cotton crop after the harvest of seed-cotton and ginning include seed, linters, hulls, oil and meal which are classified under the broad head “by-produce”. Cotton stalk is the other biomass available in the field after the harvest of seed-cotton. In general, there is lack of focus on judicious utilisation of cotton by-produce not only in India but also in all the Afro-Asian countries whose economies are influenced by cotton. The bulk of cotton seed is subjected to what is known as whole seed crushing for extraction of oil and cotton stalks are disposed of by burning in the field itself as otherwise they would harbour several insects and pests which would be harmful for the future crop. A small fraction of seeds is consumed as cattle feed while some of the stalks is used as domestic fuel. In whole seed crushing valuable components like linters, hulls, protein and large fractions of oil go unutilised instead of fetching the much-needed additional returns to farmers. Equally unacceptable is the burning off of cotton stalks that have in recent years proved to be of immense economic potential.

COTTON STALK It is estimated that about 25 million tonnes of cotton stalk is generated in India every year. Most of the stalk produced is treated as waste though a part of it is used as fuel by rural masses. The bulk of the stalk is burnt off in the field after the harvest of the cotton crop as pointed out earlier. Cotton stalk contains about 69% holocellulose, 27% lignin and 7% ash. In contrast to other agricultural crop residues, cotton stalk is comparable to the most common species of hardwood in respect of fibrous structure3 and hence it can be used for the manufacture of particle boards, preparation of pulp and paper, hard boards, corrugated boards & boxes, microcrystalline cellulose, cellulose derivatives and as substrate for growing edible mushrooms. 512 World Cotton Research Conference on Technologies for Prosperity

TECHNOLOGY FOR PARTICLE BOARDS FROM COTTON STALK Research work on the preparation of particle boards in CIRCOT dates back to 1979-80 when cotton stalk chips were used for the first time (Pandey and Mehta, 1979). Detailed studies have since been made to arrive at the appropriate process sequence and to identify process parameters that would ensure the required qualities for the particle board (Pandey and Mehta, 1980; Gurjar, 1994). The process involves the following steps: • Chipping of stalks to 1.5 - 2.0 cm size; • Rechipping to particles of 20 mesh size and 8 mesh size; • Mixing of chips with synthetic binder such as urea formaldehyde or phenol formaldehyde; • Preparation of a three-layered mat comprising coarser particles for the core layer and finer ones for the top and bottom layers; • Pressing the mat between heated platens of a hydraulic press for specific time and pressure. The board thus made is cooled to attain dimensional stability and then cut to the desired size. By using different chemicals and additives, the boards can be made water proof, fire proof, termite resistant, etc. These boards have been found to meet BIS specifications in respect of quality characteristics. Due to the lower cost of raw material and reduced power required for its conversion into finished product, the cost of particle board made from cotton stalk will be much lower than that of boards made from wood. The data presented in Table 2 clearly show that the particle boards from cotton stalks possess all the desirable properties to be used for internal as well as external applications such as false ceiling, partitioning, paneling, etc.

TABLE 2: PROPERTIES OF THREE-LAYERED PARTICLE BOARDS FROM COTTON STALK Sr. No. Properties Unit Flat Pressed Three-layer/ Cotton Stalk Multilayer Particle Board IS Particle Board 3087-1985 Type I Type II 1 Density Kg/m3 500 – 900 ---- 750 2 Average Moisture % 5-15 --- 11 3 Water Absorption 2 h soaking 24 h soaking % 10-20 40-80 20-40 4 Swelling Thickness % 8 12 9 5 Swelling due to surface Absorption % 6 9 6 6 Modulus of Rupture (MOR) Up to 20 mm N/mm2 15.0-12.5 11.0-11.0 17.6 Above 20 mm 7 Internal bond strength Up to 20 mm Above 20 mm N/mm2 0.45-0.40 0.3-0.3 0.51 8 Screw withdrawal strength Face Edge N 1250-850 1250-700 1400-860 9 Nail withdrawal strength N 1250 --- 1300

Process Parameters and Product Quality

TABLE 3: PROPERTIES OF PARTICLE BOARDS FROM COTTON STALKS WITH UREA FORMALDEHYDE AS BINDER Resin Content Thickness (mm) Density (kg/m3) Modulus of Rupture Water Swelling due to Surface (%) (N/mm2) Absorption (%) Absorption (%) 0 7.1 700 6.1 77 28 3 7.4 720 7.4 57 22 5 7.6 760 9.3 42 18 8 8.0 780 12.4 33 12 10 8.2 820 13.3 31 10 12 8.4 840 13.9 28 9 13.5 8.5 840 17.4 25 8 15 8.9 880 18.6 22 6 Increase in resin content results in improvement of product performance. Density of boards and modulus of rupture are found to increase while water absorption and surface swelling show progressive decline as the resin content is increased. Data in Table 3 demonstrate that by altering the process variables, it is possible to get particle boards of any desired quality. Cotton Stalk: An Additional Raw Material to Board Industry 513

Uses of Particle Boards The applications of particle boards are many. The application areas identified include door panel inserts, partitions, wall panels, pelmets, furniture items, floor and ceiling tiles, etc. for residential houses, commercial buildings, schools, hotels, theatres, etc. In recent years, particle board is being used increasingly in place of commercial plywood in the preparation of printer blocks. In all the above applications, substitute materials for particle boards are timber, commercial plywood, marine plywood and block board in general and for false ceilings in place of plaster of Paris. The advantages of particle board are many: • It is free from natural defects of wood, like tendency for warping. • It is easier to fix. For instance, the factory-made panel doors from particle board are available in a ready-to-fix form. Similarly, for wall panelling, false ceilings, table tops, etc., pre-laminated or pre-veneered particle boards can be used with advantage. • It is cheaper than substitute materials. • With proper protective surface coating and edge covering, particle board can be made termite proof and fire resistant. It can take a variety of surface finishes, like laminations, veneers, paint, varnish, polish, etc. Attractive wall paper can also be used as surface finish for particle boards. Even though the process for the preparation of particle boards from cotton stalks was developed a decade ago, it was not accepted by the boards industry for commercial adoption. Some of the important reasons being • Absence of cost effective supply chain mechanism • Absence of pilot plant facility for fine tuning of technology and demonstration • Non availability of data on techno-economic feasibility of the process. To address some of the above issues CIRCOT had submitted a project proposal to the Common Fund for Commodities (CFC), Netherlands, through the International Cotton Advisory Committee, USA for seeking financial assistance. The CFC realized the importance and potential of the project and sanctioned an amount of US$ 918,886 for undertaking the above study. Some of the important achievements made in the project are described below:

ESTIMATION OF AVAILABILITY OF COTTON STALK In Maharashtra, where cotton crop is grown mostly under rainfed conditions, stalks yield was as low as 1 to 1.5 tonnes per ha. The stalks yield from Karnataka ranged from 1 to 2.5 tonnes/ha in case of rainfed crop and up to 4 tonnes/ha from irrigated fields. The data clearly showed that the yield of cotton stalks from Maharashtra is the lowest. It was also noted that cotton type (variety/hybrid) plays a very important role besides conditions of growth. The information on State-wise availability of cotton stalks is given in Table 4. The survey revealed that in the North, the major part of cotton stalks is used as domestic fuel. However, farmers were ready to part with at least 50% the cotton stalk available with them for a payment of Rs. 400 to 500 (US $ 8 to 10 ) per tonne. In Gujarat the stalks are mostly burnt in the field itself. In Maharashtra, though farmers are using the stalks as household fuel, they were willing to sell it for as low as Rs. 300 to as high as Rs. 500 per tonne. In Karnataka, the survey showed that most of the farmers use cotton stalk as fuel. Some of them exchange the stalks for farm yard manure. They expressed their willingness to sell the stalks for a price of Rs. 500 per tone (1 US$ = Rs. 45/-)

514 World Cotton Research Conference on Technologies for Prosperity

TABLE 4: AREA UNDER CULTIVATION, PRODUCTION OF INDIAN COTTON & AVAILABILITY OF COTTON STALKS IN INDIA (2010-11) State Production of Cotton Area (Million Ha) Availability of Stalks (In Lakh Bales) (Million Tonnes) 1. Gujarat 90.00 2.422 9.69 2. Maharashtra 62.00 3.194 9.58 3. Andhra 53.00 1.138 3.41 Pradesh 17.50 0.604 3.00 4. Punjab 14.00 0.483 2.42 5. Haryana 18.00 0.630 1.89 6. Madhya 9.00 0.402 1.21 Pradesh 7.50 0.339 1.70 7. Karnataka 5.00 0.119 0.36 8. Rajasthan 1.50 0.050 0.15 9. Tamil Nadu 39.00 1.426 7.12 10. Orissa 170.00 6.246 21.16 11. North 67.00 1.659 4.98 12. Central 0.50 0.058 0.17 13. Southern 12.00 14. Region 15. Others 16. Loose

Total 290.00 9.436 33.58

COLLECTION AND CLEANING OF COTTON STALK Cotton is a seasonal crop harvested in India from October to February. Cotton stalks which are available only between December and May will require storage over several months to ensure adequate raw material supplies to board manufacturers for the entire year's production. Cotton stalks are bushy in nature and have very low bulk density. Collection and transportation are, therefore, expensive. Further, on storage in stick form, cotton stalks get degraded by insect attack. Success of cotton stalks as an industrial raw material would depend on the establishment of a sustainable supply chain to reach them to the industry. The entire cost economics of board manufacturing technology and the acceptance of cotton stalk by industry will depend to a large extent on the cost of raw material in a readily usable form made available at the factory gate. Therefore, the logistics of economic collection of cotton stalks, chipping and transportation from field to industry, and its proper storage in different forms at various centres are crucial factors that decide the economic viability of this raw material. Trials were conducted in three successive seasons to arrive at the most economic mode of cotton stalk collection in and around Nagpur where the crop is raised under rainfed conditions. In this region after the picking of seed cotton, the stalks are not cleared from the field immediately since there is no subsequent crop. The study started right from the stage of sensitizing farmers about the utility of cotton plant stalks. It is comparatively easier to uproot the stalks immediately after the picking is over since the moisture still present in the soil facilitates uprooting. A metallic device available locally helped in uprooting the stalks effortlessly as compared to manual pulling. It has been observed that as many as 7-8 labourers could clear the stalk from one hectare of land in a day of 8 hours. Although there was no significant difference between manual pulling and uprooting with the help of the mechanical device in respect of speed, the drudgery involved in bending and pulling with hands could be avoided in the latter case. In view of this, the simple mechanical device is recommended for uprooting the stalks. The stalks thus collected should be left for 4 to 5 days in the sun during which time, the leaves are shed. The boll rinds can be removed by gently beating the stalks on a wooden mallet. The cleaned stalks could then be subjected to chipping at a nearby chipping centre. Cotton Stalk: An Additional Raw Material to Board Industry 515

Three different models were attempted initially for economic collection and transportation of cotton stalks at three different locations near Nagpur: • Among the various models attempted, the most suitable model is the third model which comprises uprooting of stalk, storage, manual cleaning, chipping by use of a tractor-driven chipper at a centralized chipping centre not farther than 5 km from the field and transportation of chips to the factory within 50 km distance by a truck. • Transporting cotton stalks beyond 5 km before chipping and beyond 50 km after chipping so as to make it available in an appropriate form to the industry would not be an economically feasible endeavour. • On an average, the cost of cleaned and chipped stalks to be made available at the factory gate situated within 50 km from the production centre (farm) would workout to about Rs.1500-2000 (US $ 30.0 – 40.0) per tonne of the raw material with 10% of moisture.

COST OF READY-TO-USE COTTON STALK CHIPS Using the large volume of data on collection, chipping and transportation of cotton stalks, it has been possible to work out the economics of each of these operations. From this analysis the cost of cotton stalk chips made available at the particle board factory has been arrived at. Details are given in Tables 5 and 6. The raw material cost for particle board manufacture from cotton stalk thus works out to Rs. 1960 (US $ 39.2) per tonne of the ready-to-use material.

TABLE 5: COST OF COLLECTION AND CHIPPING OF COTTON STALKS Operations Cost Per Tonne Rupees US$ Uprooting and cleaning 500 10.0 Chipping 230 4.6 Tractor hiring 360 7.2 Total 1090 21.8

TABLE 6: TOTAL COST OF READY-TO-USE COTTON STALK CHIPS DELIVERED AT FACTORY SITE Operation Cost Per Tonne Rupees US$ Labour charges for uprooting, cleaning and 1090 21.8 chipping Transportation charges 320 6.4 Loading and unloading charges 50 1.0 Raw material cost 500 10.0 Total 1960 39.2

TRANSPORTATION OF STALKS AND CHIPS A critical study of the logistics of cotton stalk collection, chipping and transportation has revealed the following facts: • Transporting chipped cotton stalk is more economical than transporting the stalk as such. • It would be appropriate to employ bullock carts and tractor trolleys to carry cotton stalk to the chipping centre and use lorries to deliver the chips at the factory. • Transporting distance plays a major role in deciding the effective cost of the raw material. • Fifty kilometers should be considered as the maximum permissible distance for economic transportation of chipped material.

Storage Trials In order to find out the shelf life of cotton stalks, a large quantity of the unchipped material was stored in the open, on a stone platform. Similarly, two lots of chipped cotton stalks packed in gunny bags were 516 World Cotton Research Conference on Technologies for Prosperity

also stacked, one lot in the open and the other inside a godown. Observations were made every month for colour and insect attack, and chemical analysis was done once in a month to find out the changes if any in chemical composition (Table 7). The following facts emerged from this trial: • Insect attack is rampant in unchipped stalks kept in shade or in the open. • No significant change in the chemical composition occurs in the case of chips stored in godown. • Chipped stalks are not susceptible to insect attack. • A marginal reduction in holocellulose content is noticeable in chips stored in the open.

TABLE 7: DATA FROM CHEMICAL ANALYSIS OF STORED COTTON STALK CHIPS Sl. No. Month Moisture (%) Lignin (%) Holo Cellulose (%) Ether Extractives (%) A B A B A B A B 1 July 14.2 16.0 26.6 25.4 82.1 77.1 7.1 7.2 2 August 14.0 15.9 26.1 25.0 81.4 76.4 7.0 7.1 3 September 12.0 11.9 26.0 24.8 81.2 75.7 7.0 7.2 4 October 11.2 12.9 25.9 24.5 81.1 75.4 6.5 6.8 5 November 11.8 11.4 25.8 24.2 80.9 75.2 6.8 7.1 6 December 11.1 11.2 25.5 24.1 80.7 75.2 6.7 6.5 7 January 11.3 11.4 25.2 24.1 80.5 75.1 6.7 6.8 8 February 11.3 11.4 25.5 24.7 81.1 75.0 6.5 6.3 9 March 11.2 11.4 25.5 24.6 80.9 74.7 6.9 4.5 10 April 11.0 11.1 25.6 24.5 80.5 75.1 6.6 6.4 11 May 10.1 11.5 25.3 24.7 80.4 74.9 6.5 6.4 12 June 13.2 14.1 25.2 24.4 81.0 74.8 6.4 6.3 A: Stored in shed; B: Stored in the open

A MODEL COTTON STALK SUPPLY CHAIN FOR A 20 TPD PARTICLE BOARD PLANT It is known that for producing 1 tonne of boards, about 1.5 tonnes of chips are required. Therefore for running a 20 TPD particle board plant, 30 tonnes of chips would be required each day. Our studies have shown that it is possible to get about 1.5 tonnes of ready-to-use chips from one hectare land around Nagpur. Hence if a factory is to run only on cotton stalks it is necessary to get the material from 6000 ha of farm land which will provide 9000 tonnes of chips for board production in a 20 TPD plant working for 300 days in a year.

Storage CIRCOT study has shown that cotton stalks are normally uprooted in Nagpur area when the plant is almost dry (devoid of leaves). If such plants are uprooted and left in the field for three days and manually cleaned to remove the boll rinds before being subjected to chipping, the chipped material would be left with a moisture of around 12%. During transportation to the factory, the percentage of moisture stabilizes at about 10%. Considering that the chips have to be stored in the factory premises for at least one month, about 900 tonnes are to be stacked in its premises and the rest to be stored in 9 decentralised places by groups of farmers (say in 9 villages connected well with transport services).

Chipping Stations It has been estimated that about ten chipping stations are required to be set up. Each chipping station must be provided with one tractor-driven mobile chipper (outsourcing). Each chipper has an output rate of about 500 kg/h and can provide about 3-4 tonnes per day and in a month it is possible to generate about 90-120 tonnes of chips. Each chipping station will have to store about 1000 tonnes of chips. These chips will be stored in three stockpiles of 3 metres height and each pile is to be covered by polythene sheets to prevent spoilage during rainy season. The stock piles will be adequately separated from one other so as to facilitate loading of chips in trucks. Cotton Stalk: An Additional Raw Material to Board Industry 517

The bulk density of cotton stalk chips is about 0.14 g/cc. The average area occupied by a 3-metre high stockpile would be around 70 m2. The space required in each chipping centre would, therefore, be around ¼ of an acre.

Cotton Stalk Collection for Each Chipping Station As said earlier, about 1000 tonnes of chips are to be generated and stored in each chipping centre. For this, stalks must be collected from 600-700 hectares of land. Based on earlier trials at CIRCOT, four labourers can uproot and collect stalks from one acre in a day. This means, 10 persons are required to uproot the stalk available in 1 hectare. This also means that 10 persons would get employment for one week, only for uprooting. The same number of persons are required for cleaning the material as well. Chipping will employ four persons daily for one month.

Supply of Cotton Stalk Chips The chips will have to be transported to the factory under the direct supervision of the factory itself to ensure that supply takes place at the required rate.

ESTABLISHMENT OF 1 TPD PILOT PLANT One-tonne-per-day (1 TPD) pilot plant was commissioned for preparation of particle boards. Accordingly a pilot plant of indigenous design was procured and installed at the Ginning Training Centre of CIRCOT at Nagpur (India). The layout of the pilot plant is shown in Fig. 5 while the process sequence is illustrated in the flow-chart in Fig. 6. The pilot plant comprises an array of several machines : • Hammer Mill • Drum Chipper • Rechipper • Rotary Dryer • Glue Blender • Mat Former • Pre Press (cold) • Hydraulic Hot Press • Cutting Machine • Sanding Machine

Fig. 5: Layout of Pilot Plant 518 World Cotton Research Conference on Technologies for Prosperity

The component machines except the last two are linked by conveyors that transfer the material from one stage to the next till the boards are formed.

Pilot Plant at GTC Nagpur

Fig. 6: Flow-Chart of Particle Board Pilot Plant

Fig. 7

Material Balance After optimizing the process parameters on the pilot plant, regular production trials were undertaken and boards of various thicknesses, densities, etc. were made. On the basis of these production trials and the systematic data thus collected, a material balance for preparation of particle board from cotton stalks was worked out, as shown in the following chart. Material Balance for the Preparation of Particle Boards from Cotton Plant Stalks Cotton Stalk: An Additional Raw Material to Board Industry 519

Fig. 8 The most significant facts that emerge from the chart are the following: • One tonne of cleaned cotton stalk chips with 10% moisture yields 0.7 tonne of plain boards with 6% moisture. • To prepare 1 tonne of plain boards with 6% moisture, about 1.4 tonnes of cleaned cotton stalk chips with 10% moisture are required.

Fig. 9: Particle Boards Produced on Pilot Plant

COMMERCIAL TRIALS CIRCOT’s particle board technology subjected to refinement on the pilot plant was tried on an industrial scale in large board manufacturing units. In the first instance, about 30 tonnes of ready-to-use cotton stalk chips were supplied to M/s Ecoboard Industries Ltd. at Velapur near Pandharpur in central India followed by a second lot of 50 tonnes. The chips were delivered from Nagpur, and boards of 13.5’ x 6’ size were prepared with different thicknesses (9 mm, 12 mm & 18 mm) and surface finishes. Laminated boards thus manufactured were used for making different furniture items and also for panelling some rooms in CIRCOT, Mumbai, GTC of CIRCOT, Nagpur, DOCD, Mumbai and ICAR Headquarters, New Delhi. Tests results shown in Table 8 indicate that it is possible to prepare good quality boards in the existing industry without any modification. 520 World Cotton Research Conference on Technologies for Prosperity

TABLE 8: PROPERTIES OF COTTON STALK BOARDS MADE IN INDUSTRIAL TRIALS Properties Interior Grade Boards BIS Specification 12 mm 18 mm Density (kg/m3) 713.1 699 500-900 Modulus of Rupure (N/mm2) 15.4 12.0 11.0 Tensile Strength (N/mm2) 0.9 0.5 0.3 Water Absorption (%) 2 hours 20.4 56 40 Water Absorption (%) 24 hours 42.2 95 80 Screw Withdrawal (N)Face 1762 1610 1250

TECHNO-ECONOMIC FEASIBILITY OF PARTICLE BOARD PLANTS The technical feasibility of particle board manufacture from cotton stalk was examined on the basis of industrial trials conducted at M/s Eco-board Industries Pvt. Ltd., Pune and Archid Ply Industries, Mysore. In both the industries, the trials were successful and good quality boards suitable for lamination were manufactured. No technical problems were encountered during the processing and no changes or modifications in the existing plant were found necessary. For an examination of the economic viability of cotton stalk as raw material for particle board manufacture, a 30-tonne trial was undertaken at M/s Eco-board Industries Pvt. Ltd., Pune having installed capacity of 200 tonnes/day but running at 60% capacity utilization. In these trial boards of 9 mm, 12 mm and 18 mm were prepared. The data in Table would substantiate the fact that particle board production from cotton stalks in an established board manufacturing unit is indeed an economically viable proposition. Thickness Density (g/cc) Production Cost Per sq. ft. Selling Price Per sq. ft. Profitability % Rs. US $ Rs. US $ 9 mm 0.73 13.94 0.28 17.1 0.34 22. 7 12 mm 0.72 15.00 0.30 18.63 0.37 24.2 18 mm 0.72 19.25 0.38 24.53 0.49 27.4

COST ESTIMATION FOR A PARTICLE BOARD PLANT OF 10 TPD CAPACITY On the basis of extensive information gathered from wide ranging R & D efforts under the project, it has been possible to work out the profitability of particle board plants. For a 10 TPD plant the capital investment comprising land, buildings and plant & machinery will work out to over Rs. 58 million (US $ 1.16 million) while the production cost after duly considering depreciation, interest on investment etc would be around Rs. 38.76 million (US $ 0.78 million). The cost of production per tonne of particle board would be about Rs. 12,920 (US $ 258). At current selling price levels for particle boards, the return on investment will work out to about 19%. Details are given below in tabular form.

Production Highlights Production capacity: 10 TPD (384 boards of 8’x4’x12 mm), Raw material used:15 TPD of cleaned chips/day No. of days of production in a year : 300 No. of shifts per day: 3 Total production in a year: 3000 tonnes

TABLE 9: PROJECT COST AND PRODUCTION COST IN CASE OF A 10 TPD PLANT A Capital Investment Rs. (Million) US $ 1. Land & Building Land : about 1 hectare 2.50 50000 Building : (Area : About 10,000 sq.ft., raw material storage) 4.50 90000 2. Plant and Equipment 42.20 844000 Table 9 (Contd.)… Cotton Stalk: An Additional Raw Material to Board Industry 521

…Table 9 Contd. 3. Auxiliary and service Equipments, Margin money for working capital 90.00 180000 Total Project Cost 58.20 1164000 B Cost of Production 1. Raw Material & Utility 20.50 410000 2. Labour & Supervision 3.51 70200 3. Repairs , Maintenance & Overheads 2.80 56000 (I) Total Manufacturing Cost 26.81 536200 (II) General Expenses 1.75 35000 (III) Depreciation & Interest 10.20 204000 Total cost of production B (I+II+III) 38.76 775200 Cost of production per tonne of board Rs.12,920 258

TABLE 10: PROFITABILITY OF A 10 TPD PARTICLE BOARD PLANT Rs. (Million) US $ 1. Gross Annual Income 49.77 995400 2. Annual Cost of Production 38.76 775200 3. Annual Return (2-3) 11.01 220200 4. Return on Investment (ROI) 19% 19% *Selling price per unit (8’x4’x12 mm) @ Rs. 13.5 per sq. ft. = Rs. 432.00 (US $ 8.64)

COST ESTIMATION FOR A PARTICLE BOARD PLANT OF 20 TPD CAPACITY A similar exercise has been done in respect of a 20 TPD plant for which the capital investment including cost of land, buildings and plant & machinery works out to over Rs. 75 million (US $ 1.50 million). The production cost, after taking into consideration depreciation, interest on investment etc., works out to about Rs. 74.60 million (US $ 1.49 million). The production cost per tone of particle board would be about Rs. 12430 (US $ 249). The return on investment would be about 33.5% which is significantly higher than for a 10 TPD plant. Details are shown in tabular form.

Production Highlights Production capacity: 20 TPD (770 boards of 8’x4’x12 mm) Raw material used: 29 TPD of cleaned chips/day No of days of production in a year: 300 No. of shifts per day: 3 Total production in a year: 6000 tonnes

TABLE 11: PROJECT COST AND PRODUCTION COST IN CASE OF A 20 TPD PLANT A Capital Investment Rs. (Million) US $ 1. Land & Building Land : about 1 hectare 2.50 50000 Building: 25,000 sq.ft. 9.05 181000 2. Plant and Equipment 50.00 1000000 3. Auxiliary and service Equipment 2.50 50000 4. Margin money for working capital, pre-operative expenses, 11.17 223400 contingency etc. Total Project Cost 75.22 1504400 B Cost of Production (80% capacity utilization) 1. Raw Material & Utility 41.50 830000 2. Labour & Supervision 5.50 110000 3. Repairs & Maintenance 2.70 54000 4. Plant overheads 1.00 20000 (I) Total Manufacturing Cost 50.70 1014000 (II) General Expenses 3.10 62000 (III) Depreciation & Interest 20.80 416000 Total cost of production B (I+II+III) 74.60 1492000 Cost of production per tonne board Rs. 12430 249

522 World Cotton Research Conference on Technologies for Prosperity

TABLE 12: PROFITABILITY OF A 20 TPD PARTICLE BOARD PLANT Rs. (Million) US$ 1. Gross Annual Income 99.79 1995800 2. Annual Cost of Production 74.60 1492000 3. Annual Return (2-3) 25.19 503800 4. Return on Investment (ROI) 33.5% 33.5% *Selling price per unit (8’x4’x12 mm) @ Rs. 13.5 per sq. ft. : Rs. 432.00 (US $ 8.64)

CONCLUSIONS FROM THE TECHNO-ECONOMIC STUDY • A particle board plant with an installed capacity of 10 tonnes per day and involving a capital investment of about Rs. 60 million (US $1.6 million) can ensure a profitability of about 20% with cotton stalk used as the raw material. • A plant with a higher capacity of 20 TPD can bring higher returns of up to 33%. • For sustainable supply of raw material, an agency should be identified for organizing collection and chipping of cotton stalks and delivering the chips at the particle board factory. • Existing particle board plants manufacturing boards from hardwood, bagasse, etc. can use cotton stalk as an additional raw material.

POST PROJECT SCENARIO The successful completion of the project in 2009 encouraged many farmers, entrepreneurs and board industries particularly in Maharashtra and Gujarat to collect stalks for use in board making. a) M/s. Godavari Particle Board Palnt (10 TPD) near Nanded in Maharashtra have been using cotton stalks for the preparation of particle boards. They are preparing blended boards also (cotton stalks and bagasse). They are able to collect about 500-1000 tonnes of cotton stalks through an organized collection mechanism. This exercise provided employment specifically to landless labourers. About 100 farmers are involved daily in collection, chipping and transportation. b) A 100 TPD particle board plant based on cotton stalks was commissioned in 2009 by M/s. Rushil Decor Ltd. In Dhrangadhra village in Surendranagar District, Gujarat. Their annual requirement of cotton stalks is 50,000 tonnes. They have identified six cotton stalk collection centres, each centre covering an area of 8000 ha to 25,000 ha in a distance of about 15-20 km. They identified contractors, panchayat representatives, self help women groups and Rural Development Agencies to undertake this job. This plant with innovation collection mechanism generated 4,00,000 man days employment annually benefitting 1000 farmers and 5,000 landless labourers. c) Based on CIRCOT technology, CIRCOT in collaboration with MITCON consultancy services prepared a bankable project proposal for setting up of a 10 TPD particle board manufacturing plant from 100% cotton stalk at Washim, Maharashtra. Ministry of Social Welfare, Govt of Maharashtra sanctioned a loan of 680 lakhs to Tulsai Magasvargiy Audyogik Sahakari Sanstha (TMASS), Washim. The construction of the plant is in progress and expected to be over by June, 2011. About 100 farmers will be involved in the procurement and supply of cotton stalks and about 150 persons will be involved in direct and indirect employment. d) M/s. Bajaj Steel Industries, Nagpur have already started procuring cotton stalks by mechanically uprooting, baling and transporting the baled stalks to the centralized chipping centres. Their interest is to supply the stalks as a fuel to boilers. e) Many NGO’s in and around Akola, Jalgaon and other places in Maharashtra have started collecting cotton stalks and supply to many user industries. f) Apart from this, M/s. Aurobindo Laminations in Nagpur are using cotton stalks in making particle boards.

Cotton Stalk: An Additional Raw Material to Board Industry 523

ACKNOWLEDGEMENT The authors are grateful to: 1. CFC, Netherlands for the financial assistance. 2. ICAC, USA for constant help, guidance, supervision and encouragement. 3. ICAR, for providing all the infrastructural facilities for effective monitoring , guidance and permission to participate in the meeting and presentation of data. 4. To all my project colleagues, specially to Dr. S. Sreenivasan, Former, Director, CIRCOT for constant and continuous support and guidance. 5. To. M/s. Eco-Boards, M/s. Jolly Boards, M/s. Archid Ply and other industries for permitting to undertake commercial trials.

REFERENCES [1] Balasubramanya R. H., Shaikh A. J., Paralikar K. M. and Sundaram V., Spoilage of Cotton Stalks During Storage and Suggestions for its Prevention, J. Indian Society for Cotton Improvement, 15:34-39, (1990). [2] Sundaram .V., Balasubramanya R. H., Shaikh A. J., Bhatta I. G. and Sitaram M. S., Utilisation of Cotton Stalks, J. Indian Society for Cotton Improvement, 14(1):94-99 (1989). [3] Pandey S. N. and Shaikh A. J., A study on Chemical Composition of Cotton Plant Stalk of Different Species, Indian Pulp and Paper, 41: 10-13 (1986). [4] Pandey S. N. & Mehta A. K., Industrial Utilisation of Agril. Products : Cotton Plant Stalk, Research and Industry, 24(2):75, (1979). [5] Pandey S. N. & Mehta A. K., Particle Boards from Cotton Stalks, Research and Industry, 25:67-70, (1980). [6] Gurjar R. M., Cotton Stalk Particle Boards – A Timber Substitute, Research and Industry, 39(9):153-155, (1994). [7] Mahanta D., Particle Board and Hardboard from Cotton Stalk, Indian Chemical Manufacturer, 22(8):15-21, 1984. [8] Guler C. & Ozen R., Some Properties of Particleboards made from Cotton Stalks (Gossypium hirsitum L.), European Journal of Wood and Wood Products, 62(1), 40-43, March, 2004. [9] Negi J. S. and Chawla J. S., Composite Boards from Cotton Stalks, Research and Industry, 40(12):267-271, (1995). [10] Narayanamurti D., Fibre Boards from Indian Timbers, Indian Forester, 86(1): 5-15, (1960). [11] Pandey S. N., Das R. N. and Day A., Particle Board from Jute & Its Lamination – A new Process, Research and Industry, 35:227-229, (1990). [12] Negi J. S., Utilisation of Lantana camera – Laminated composite Boards, Research and Industry, 31(1):22, (1994). [13] Fadl N. A. and Sefain M., Hardboard from Retted Rice Straw and Cotton Stalk, Research and Industry, 28(8):95, (1983-84). [14] Balasubramanya R. H., Shaikh A. J. and Sreenivasan S., Cotton Crop and Industry Waste , in Environment and Agriculture Edited by Chadha K. L. and Swaminathan M. S., Malhotra Publishing House, New Delhi: 2008. [15] Khandeparkar, V. G., Balasubramanya, R. H. and Shaikh, A. J. (1993), A Process for the Preparation of Paper Grade Pulp from Cotton Plant Stalk by Anaerobic Digestion. (Indian Patent No. 176891, July, 1993). [16] Fadl N. A., Sefain Z. and Rekha M., Hardening of Cotton Stalk Hardboards, Indian Pulp and Paper, 33(2):3, August (1978). [17] Fadl N. A., Heikal S. O., El-Shinnawy and Moussa, M. A., Hardboard from Cooked Rice Straw Blended with Cotton Stalks, Indian Pulp and Paper, 35(1):19-22, (1980). [18] Pandey, S. N. and Shaikh, A. J., Utilisation of Cotton Plant Stalks for Production of Pulp and Paper, Biol. Wastes, 21, 63- 70, (1987). [19] Shaikh, A. J., Blending of Cotton Stalk Pulp with Bagasse Pulp for Paper Making, Biol. Wastes, 31, 37-43, (1990). [20] Pandey S. N., Ghosh I. N. & Day A., Utilisation of Non-wood Fibrous Ra material for Pulp, Paper and Board, Research and Industry, 40(12):285-288, (1995). [21] Pandey S. N. and Shaikh A. J., Production of Various Grades of Paper from Cotton Plant Stalk, Indian Pulp and Paper, 40: 14-18 (1985). [22] Balasubramanya, R. H., (1981), An Edible Mushroom Crop on Cotton Stalks, J. Indian Soc. Cotton Improv., 6, 104-105. [23] Balasubramanya R. H. and Khandeparkar V. G., Mushroom Crop on Spent Cotton Stalks, Indian Society for Cotton Improvement J., 14:85-86, (1989). 85

Differential Speed Setting Facility for Roller and Beater in Gins for Higher Ginning Rates

S.B. Jadhav and K.R.K. Iyer Former Senior Scientist and Former Director, CIRCOT, Mumbai, India

Abstract—In the present-day double roller (DR) gin, being used in many cotton-growing countries of the world, the rollers rotate with a speed of about 90 rpm while the reciprocating knives (beaters) make about 1000 oscillations per minute. Studies at CIRCOT have shown that different speed combinations of the rollers and the beaters can produce spectacular changes in ginning rate (kg/hr) in cottons of different staple classes. In the conventional DR gin, differential speed variation is not possible because both rollers and beaters are operated by the same drive mechanism. As a result, when the rollers are made to rotate faster, the beaters too would get faster making more number of oscillations. In the modified DR gin designed at CIRCOT, two independent drives are provided for the rollers and the beaters whereby differential speed adjustment is rendered possible. It has been shown that higher roller speeds such as 110 to 160 rpm coupled with a beater speed of 1000 oscillations per minute can increase the ginning rate by 50-140 per cent. The increase is found to be more in the case of cottons of longer staple lengths. Interestingly, higher rates of processing do not cause fibre damage. The new gin design holds promise for a substantial reduction in processing cost.

INTRODUCTION Ginning rate in the double roller (DR) gins is far lower than that in the saw gin1. Though slower, the DR gin is gentler to the fibre and preserves the quality of lint as compared to saw gin2. The Indian ginning industry processes 85% of cotton with roller gin3 whereas in the world as a whole roller ginning accounts for only 15%. However, the slow ginning rate of the roller gin has made it expensive to maintain and operate. In this gin, the roller and beater are driven with a single drive such that the ratio of the beater frequency to roller speed remains fixed. There is no provision for altering this ratio, which researches have revealed, 4-6 controls the efficiency of the process while ginning different varieties of cotton. Attempts to increase the ginning rate have been made by Gallium and Armojo7 and Chellamani et al8 . These researchers used rotary knife system instead of oscillating knife for beating the seeds to separate them from the fibre. The present exercise was aimed at designing an improved version of the double roller gin by providing separate drives for the roller and the beater to increase the ginning rate. This provision is not available in any of the existing commercial models of DR gin.

THE REDESIGNED GIN The gear box in the DR gin was suitably redesigned and installed on the gin stand. The modification allows independent drives for the roller and the beater whereby any desired speed of the roller and beater is possible. The redesigned gin is known as variable speed (VS) gin. The machine employed for modification was a commercial Platt’s DR gin. The modified gin retains all the machine elements of the DR gin except the gear box. In the conventional DR gin the gears controlling the motion of the roller and beater are linked to a single shaft and thus have fixed angular frequency, (generally in the ratio of 1:10). In the VS gin there are two independent shafts, one for the roller and the other to effect the reciprocating motion of the beater by means of a crank, each provided by a different motor. The machine diagram of VS gin is shown in Fig.1.

Differential Speed Setting Facility for Roller and Beater in Gins for Higher Ginning Rates 525

Fig. 1: Modified DR Gin [G-Gear Box, W-Gear Wheel, P-Pul-Ley R-Roller, M-Moving Knife, O-Beater Shaft, F-Fixed Knife, and C-Conecting Arm]

Machine Specifications The motor that drives the roller rotates with the speed of 1420 rpm and is fitted with a step pulley. The diameter of the step pulley varies in steps of 7.5, 6.0 and 4.5 inch while the diameter of the roller driver pulley connecting the gear box is kept at 6 inch. This pulley drives the rollers with the speeds of 160,130 and 110 rpm. The other motor, which drives the beater assembly, is also fitted with the step pulley having diameters of 6 and 4.5 inch. The beater driver with a pulley of 9 inch diameter thus oscillates the beater with frequencies of 1000 and 750 opm. In conventional DR gin, roller speed is 95 rpm and beater oscillates with 950 opm. This combination was kept as the control for all the eight cottons in the present experiment. The sliding weights, which exert force on the roller, were kept at 30 inch away from the fulcrum of the lever at a pre-determined position for maintaining constant pressure between roller and fixed knives. The overlap width between fixed knives and moving knives was varied between 9 mm to 11 mm to suit the varieties processed in the tests.

Procedure Experiments were conducted with the variable speed (VS) gin to determine the optimum roller speed and beater frequency in relation to various characteristics of seed cotton being ginned. The staple length, short fibre content in the resultant lint, incidence of neps, seed coat fragments, and ginning percentage have been considered in the optimization study. The experiment was carried out in the following steps. The first experiment was conducted with a constant beater frequency of 1000 opm successively coupled with roller speeds of 160, 130, and 110 rpm. The results are designated as S1, S.2 & S3 respectively in Table 1 as well as Table 3. For the reduced speeds of 130 & 110 rpm the V-belt was shifted to the appropriate pulley fixed on the motor shaft. In all experiments, 10 kg of seed cotton from each variety was processed thrice at each combination of roller and beater speeds. The second set of tests was conducted with the beater frequency of 750 opm for the same three roller speeds (160,130, &110 rpm) using another pulley combination for the beater drive. Here too the results are designated as S1, S2 & S3 in Table 2 as well as in Table 4. The third and final set of test was conducted on the same ginning machhine operated with the manufacturer’s recommended speed of roller (95 rpm) and oscillation frequency (950 opm) of the beater. This set of tests was used as the control while critically analyzing the results. The data are designated as “C” in all the four Tables. Tables 1 and 2 summarize results of experiments together with other performance data while Tables 3 & 4 show important fibre properties of lint processed in various trials. Fibre tests were done on HVI and AFIS machines. Three tests were carried out for each of the control and treated samples, and the average of three values for each quality parameter was recorded. All the tests were conducted at standard conditions of humidity and temperature (65 + 2% RH & 27 + 20 C ) 526 World Cotton Research Conference on Technologies for Prosperity

RESULTS AND DISCUSSION Influence of Machine Parameters on Lint Out-turn Two important machine parameters that influence the ginning rate and lint quality in ginning are the speed of the roller and the frequency of the oscillating beater. The effect of the roller speed and the beater frequency on ginning rate (GOT) and related parameters will be clear from data in Tables 1 and 2.

TABLE 1: GINNING OUT-TURN AT DIFFERENT ROLLER SPEEDS WITH A BEATER FREQUENCY OF 1000 OPM Variety Treatment Ginning Rate Lint Out- turn Ginning % Increase in % Increase in Kg/hr Kg/hr (%) Ginning Rate Lint Out-turn G Cot DHy 7 S1 180 72 33.7 71.0 80.0 S2 180 72 33.8 71.0 80.0 S3 180 72 33.6 71.0 80.0 C 105 40 34.0 - - K.2 SI 163 60 35.9 103.7 106.8 S2 143 45 35.7 78.7 55.1 S3 100 38 35.9 25.0 31.0 C 80 29 36.0 - - Jayadhar S1 254 82 31.8 69.3 60 .7 S2 171 60 31.6 14.0 17.6 S3 240 73 31.8 60.0 43.1 C 150 51 32.0 - - H.8 S1 170 60 35.0 73.4 71.4 S2 189 69 35.8 92.8 97.1 S3 160 52 35.8 63.3 48.5 C 98 35 35.0 - - JKHy.1 S1 200 65 35.4 94.1 75.6 S2 138 53 35.5 33.1 43.2 S3 137 53 35.4 33.0 43.2 C 103 37 35.6 - - G Cot 10 S1 160 58 32.6 66.7 61.1 S2 100 36 32.4 4.1 0.0 S3 112 41 32.8 16.6 13.8 C 96 36 33.0 - - DHB.105 S1 166 60 35.6 44.3 50.0 S2 175 62 35.2 52.5 55.0 S3 172 62 35.5 49.5 55.0 C 115 40 35.8 - - DCH.32 S1 220 72 33.3 158.8 140.0 S2 151 58 33.2 77.6 76.6 S3 167 53 33.5 96.4 93.0 C 85 30 33.5 - - Sl: 160:1000, S2: 130:1000, S3: 110:1000 and C: 95:950

TABLE 2: GINNING PERFORMANCE AT DIFFERENT ROLLER SPEEDS WITH A BEATER FREQUENCY OF 750 OPM Cotton Treatment Ginning Rate Lint Out- turn Ginning % Increase % Increase Kg/hr Kg/hr (%) In Ginning Rate in Lint Out-turn S1 145 57 33.7 38.0 42.5 G Cot Hy.7 S2 140 56 33.9 33.3 40.0 S3 120 48 33.6 14.3 20.0 C 105 40 34.0 - - SI 109 42 35.9 45.3 44.8 K.2 S2 82 35 35.7 9.3 20,6 S3 82 31 35.9 9.3 6.8 C 75 29 36.0 - - S1 180 66 31.8 20.0 29.4 Jayadhar S2 160 58 31.6 6.7 13.7 S3 164 57 31.8 9.3 15.7 C 150 51 31.0 - - Table 2 (Contd.)… Differential Speed Setting Facility for Roller and Beater in Gins for Higher Ginning Rates 527

…Table 2 Contd. S1 120 46 35.0 22.4 31.4 H.8 S2 116 45 35.8 18.4 28.5 S3 113 45 35.8 15.3 28.5 C 98 35 35.0 - - S1 130 52 35.4 44.4 36.8 JKHy.1 S2 100 41 35.5 11.1 7.8 S3 100 41 35.4 11.1 7.8 C 90 38 35.6 - - G Cot 10 S1 113 40 35.6 17.7 111 S2 105 37 35.4 9.4 2.8 S3 105 38 33.8 9.4 5.5 C 96 36 33.0 - - S1 125 50 35.6 8.6 25.0 DHB.105 S2 124 50 35.2 7.8 25.0 S3 120 48 35.5 4.3 20.0 C 115 40 35.8 - - S1 150 48 33.3 80.7 60.0 DCH.32 S2 150 48 33.2 80.7 60.0 S3 120 46 33.5 44.6 53.3 C 83 30 33.5

TABLE 3: QUALITY PARAMETERS OF LINT AT DIFFERENT ROLLER SPEEDS WITH A BEATER FREQUENCY OF 1000 OPM Cotton Treatment 2.5% Span Short Fibre Mic (10-6g/in) Mat. Fibre Strength Neps/g SCF/g Length (mm) % Ratio g/tex G Cot DHy S1 22.3 13.5 52 0.89 20.8 95 11 7 S2 23.3 13.4 5.3 0.90 21.6 128 20 S3 23.2 14.1 5.3 0.87 194 139 27 C 20.8 11.1 5.3 0.87 21.5 118 16 K.2 S1 24.4 20.0 4.3 0.79 20.8 261 48 S2 24.2 19.7 4.2 0.83 20.4 250 55 S3 22.6 18.3 4.2 0.79 22.5 280 40 C 23.8 15.2 4.0 0.77 21.6 243 44 Jayadhar S1 24.7 15.0 4.3 0.90 19.1 193 19 S2 23.3 15.8 4.4 0.88 16.1 182 16 S3 22.7 13.7 4.3 0.89 15.7 195 18 C 24.7 10.7 4.4 0.91 15.4 161 16 H.8 S1 25.5 14.1 4.4 0.79 22.5 156 17 S2 25.3 13.7 4.4 0.94 20.8 115 11 S3 24.7 15.0 4.5 0.89 22.5 92 15 C 25.8 10.3 4.5 0.86 22.8 91 12 JKHy.1 S1 28.2 15.6 3.8 0.80 23,7 185 24 S2 26.1 18.5 3.6 0.79 21,6 192 31 S3 25.6 10.9 3.7 0.78 23.6 157 17 C 25.5 12.7 3.7 0.86 23.6 144 26 G.Cot 10 S1 25.6 13.9 4.3 0.86 20.9 167 48 S2 24.8 14.7 4.4 0.85 19.9 138 38 S3 25.0 13.4 4.0 0.89 17.9 155 51 C 26,4 10.2 4.3 0.86 18.9 124 24 DHB.105 S1 28.8 9.9 2.9 0.87 23.5 185 22 S2 27,4 13.4 3.2 0.80 21.6 170 23 S3 27.0 16.6 3.3 0.87 19.9 175 21 C 27.9 10.0 3.4 0.78 20,8 159 15 DCH.32 S1 32.7 13.6 2.9 0.78 25.5 212 19 S2 31.8 13.1 3.2 0.78 21.6 190 18 S3 30.9 12.3 3.3 0.77 21.4 200 19 C 33.1 7.5 3.4 0.77 21.5 170 16

528 World Cotton Research Conference on Technologies for Prosperity

TABLE 4: QUALITY PARAMETERS OF LINT AT DIFFERENT ROLLER SPEEDS WITH A BEATER FREQUENCY OF 750/MIN Cotton Treatment 2.5% Span Short Mic Mat. Fibre Neps/g SCF/g Length Fibre % (10-6g/in) ratio Strength (mm) g/tex G Cot DHy.10 S1 22.8 7.8 5.0 0.93 21.0 121 14 S2 22.7 13.5 4.9 0.91 21.0 147 19 S3 23.2 11.1 5.5 0.94 21.6 165 30 C 20.8 11.1 5.3 0.97 21.5 118 16 K.2 S1 25.8 11.5 4.1 0.87 22.4 205 35 S2 23.1 18.9 3.9 0.78 19.2 305 50 S3 23.2 18.9 3.4 0.78 19.9 410 50 C 23.8 15.2 4.0. 0.79 21.6 243 44 Jayadhar S1 24.4 9.8 4.3 0,89 19.6 140 12 S2 24.5 11.5 4.8 0.88 19.9 229 13 S3 24.4 13.6 4.1 0.87 18.4 202 23 C 24.7 6.7 4.4 0.91 15.4 161 11 H.8 S1 24.0 16.9 3.4 0.79 18.3 135 35 S2 25.2 15.2 4.1 0.84 22.9 137 15 S3 25.3 12.7 4.3 0.84 20.8 138 17 C 25.8 10.3 4.5 0.86 22.8 91 12 JKHy.1 S1 27.3 13.6 3.3 0.79 24.8 196 42 S2 24.5 17.9 3.2 0.75 24.7 259 38 S3 26.4 10.6 3.2 0.81 24.4 326 48 C 25.5 14.4 3.7 0.86 23.6 144 26 G Cot 10 S1 25.2 14.8 3.5 0.80 23,7 116 27 S2 23.7 13.6 3,2 0.78 25.2 171 17 S3 23.6 16.9 3.0 0.82 22.4 194 31 C 26.4 12.4 4.0 0.86 18.9. 124 24 DHB.105 S1 27.7 12..9 3.1 0,75 21.5 179 30 S2 28.3 12.1 2.7 0.75 24.8 164 21 S3 27/6 14.7 2.6 0.75 22.9 200 41 C 27.9 10.0 3.4 0,78 20.8 159 15 DCH.32 S1 35.4 11.4 2.8 0,79 28.2 202 18 S2 33.4 12.6 2.8 0.77 27.1 190 17 S3 33,3 9.8 2.5 0.78 23.8 200 16 C 33.1 7.5 2.9 0.77 21.5 170 16 From Table 1 it will be clear that the ginning rate and the lint out-turn in almost all the experiments with changed speed ratios are much higher than with the normal (control) speed of roller and beater. Among the three roller speed ratios (S1-160: 1000, S2-130: 1000 & S3-110: 1000), the highest ratio (160:1000) gave the maximum ginning rate in all the cottons. The maximum increase in ginning out-turn for the longest staple cotton DCH.32 was observed to be 158.8%. The increase in the lint out-turn ranges from 50% for DHB.105 to a maximum of 140% for DCH.32. The speed ratio of 130:1000 gave the highest ginning out-turn for medium staple like G.Cot.DHy.7 (80%) followed by DHB.105 (55%) Table 5 gives the increases in ginning rate and lint out-turn averaged for for all the eight cottons tested.The averages are found to be the highest for a roller speed of 160 rpkm coupled with the beater frequency of 1000 opm. The numerical difference between percentage increase in ginning rate and lint out –turn for a given variety is dictated by its ginning percentage.

TABLE 5: AVERAGE INCREASE IN THE GINNING RATE AND LINT OUT-TURN OVER THE CONTROL Sr. No Speed Ratio % Increase in Ginning Rate % Increase in Lint Out-Turn Experiment-1 1 S1 (160: 1000) 84.8 80 2 S2 (130:1000) 52.5 49.8 3 S3 (110:1000) 51.5 50.8 Experiment-2 1 S1 (160:750) 27.4 29.7 2 S2 (130:750) 20.3 22.5 3 S3 (110:750) 12.1 13.2 It is well known that for a given variety with an average staple length of say, 24 mm,, there would be some fibres with a length of 30 mm. The tips of such fibres are most likely to be picked up and gripped first. Other shorter fibres are entangled with them and are dragged forward near the ginning point along with the seed and then get ginned. The different speeds have given different out-turns for cottons and the reasons for the same are discussed. Differential Speed Setting Facility for Roller and Beater in Gins for Higher Ginning Rates 529

The rollers employed in the conventional double roller gin are of 16.5 cm diameter rotating at a speed of (n) 95 rpm such that the surface speed (V= ω n d/2) lies between 48 and 50 m/min. The beater oscillates with a frequency of 950 opm. Since the beater oscillates symmetrically with respect to the edge of the fixed knife, one half of the time is utilized for feeding seed-cotton and the other half is for ginning. Since the beater frequency is 950 opm, during the feeding interval of 1/30 sec, the rollers move a distance of 26 mm. If it is assumed that during the feeding interval, the probability of a fibre of average length being picked up by the roller is p (0

Since the feeding time per gin cycle (tf) is half of this time t

tf =0.03 sec.

The total movement of the roller during the time tf is 125.6 x 0.03 =3.768cms =37.7mm. Similarly for 130, 110 and 95 rpm of roller speeds the corresponding movement of the roller during the same time would be 30.6, 25.9 and 22.3 mm. respectively. The time needed by a fibre on a seed to be caught between the roller and the knife-edge is a statistical parameter and can be taken as

p x t f where p stands for the probability factor. At the roller speed of 160 rpm, the fibres of average length (p x .37.7 mm) are caught between the roller and the knife-edge and for them ginning starts in the first cycle itself. Thus for ginning long and extra long cottons the highest speed of 160 rpm is justified and is expected to yield higher lint out-turn than by employing the lower speeds. It may be noted that the experiments performed with a roller speed of 130 rpm always results in higher yield for medium staple cottons where the staple length varies between 24 and 30 mm. It is thus concluded that the higher speed has a positive impact on the probability factor. 530 World Cotton Research Conference on Technologies for Prosperity

Most of the Indian cottons are of medium staple category and for them a roller speed of 130 rpm coupled with a beater frequency of 1000 opm is found to be optimum for high lint yield. The same condition cannot be taken for long staple cottons. In such cases, even if the grip is strong enough to prevent fibreslippage, the seed may fail to get ginned in the first cycle. Nevertheless, it will utilize subsequent cycles to get ginned. This would mean that ginning will be delayed and the out-turn will be lower. The other experiment with the same roller speeds combined with the lower oscillation frequency of the beater (750 opm) also gives comparatively higher output (Table 2) than in the control experiment with higher beater frequency (1000 opm). In this case, the feeding rate of seed cotton is more but the beater frequency is less, thereby decreasing the ginning rate.

CONCLUSION The VS Gin is an excellent replacement for the conventional DR gin presently being employed in Indian ginning industry. It has the flexibility to permit optimization of settings to increase the productivity for all types of cotton, short, medium and long staples. For efficient ginning of cotton, the fibre must be dragged toward the ginning point i.e. at the edge of the fixed knife. This can be achieved by setting different roller speeds relative to staple length of cotton under the ginning process. At the recommended speed for the roller, the oscillating beater separates the seed from the fibre with minimum number of strokes, at the same time increasing the ginning out-turn and preserving fibre length, which is the most important quality parameter of the lint. The following are the salient features of the performance of the VS. Gin: • In most cottons the ginning out-turn has recorded increase, ranging from 60% to 100% over the production possible with the old model gin. • The roller speed of 160 rpm combined with an oscillation frequency 1000 cycles per minute for the beater is the best for ginning extra-long Indian cottons. • For medium staple cottons in the length range of 24-28 mm, a roller speed of 130 rpm in combination with 1000 oscillations per minute for the beater is the most appropriate. • The combination of 110 rpm for the roller and 1000 cycles per minute for the beater is ideal for the cottons having length 20 to 23 mm. • Important fibre parameters such as 2.5% span length, fibre tenacity and other characters are preserved.

ACKNOWLEDGEMENT The authors are grateful to Dr. A. J. Shaikh, Director CIRCOT for according permission to present this paper at WCRC-5.

REFERENCES [1] Comparative Performance of Different Types of Gins, A report submitted by CTRL, ATIRA & AIFCOSPIN to IDA/IBRD, Sponsored by NCDC, India (1984). [2] Sundaram, V., "Contribution of Cotton Technological Research Laboratory to the Improvement of Cotton Ginning in India", CTRL Publication, New Series, No. 144 (1980). [3] Chaudhary, M Rafiq, "Harvesting and Ginning of Cotton in the World", Proceedings of Beltwide Cotton Conferences, Vol.2 of 2 pp 1617-1619 (1997). [4] Johnson, F., Mayfield, W., Lalor, W. F. and Hughes, S. F. "Ginning Developments", Textile Asia, 23(10), 49-52(1992). [5] Vizia, N.C. and Iyer K.R.K.; "Ginning Research in India and Future Prospects", National Seminar, Mumbai (1999).. [6] Nanjundayya, C. and Iyengar, R. L. N., “A Resume of Various Investigations Carried Out on the Ginning Of Indian Cottons”, Tech. Bull. Series, B No.50, Tech. Laboratory, Matunga, Bombay (Oct 1955). [7] Gillium, M. W. and Armojo, C.B., American Society for Agriculture Engineers, Vol.43 (4) 809-817 (2000). [8] Chellamani, K.P. Parthasarathy, N. and Jaikumar, V., "Design and Development of High Production Gin and Lint Cleaner", Asian textile Journal, (June 2000). 86

Influence of Quality Attributes of Individual Bales on Yarn Quality

R.P. Nachane CIRCOT, Mumbai, India

Abstract—Cotton being a commercial crop of great economic importance, there exists a value chain in the sense that the seed cotton is converted into lint and through the yarn and fabric route into garments and made ups for both internal consumption and export. However, in this conventional value chain there are several weak as well as missing links. The crucial unit operation involved in the value chain is ginning, i.e., conversion of seed cotton into lint, is still considered to be one of the weakest links characterized by excessive use of energy, low productivity, absence of cleaning and lack of facilities for quality assessment of the lint that this sector produces. Even though the Spinning Industry in India is modernized, it mainly depends upon the ginning industry for raw material. Cotton bales prepared in ginning industry are not individually tagged with fibre characteristics. Therefore, spinning units are procuring cotton bales on the basis of fiber characteristic values got from random sampling of bales. This special study has been carried out to find out the effect of segregation of bales, mainly based on fineness, after tagging of individual bales according to fibre properties, on the yarns so produced. Results indicate that for high micronaire of above 4.5 for a given variety grown in one location, no statistically significant differences in yarn properties are observed. However, for yarns produced from finer cottons of less than four micronaire, many of the yarn properties are highly influenced by the fineness. It is therefore recommended that individual bale tagging with segregation of bales based on fineness can result in better quality yarns, leading to better quality fabrics and garments.

INTRODUCTION The Indian Textile Industry uses about 60% cotton as its raw material, unlike the global textile industry that has a 40:60 mix of cotton and manmade fibres. There has been a phenomenal increase in cotton production in India in recent years. Cotton being a commercial crop, there exists a value chain in the sense that seed cotton is converted into lint and through the yarn and fabric route into garments and made-up for both internal consumption and export. However, in the conventional value chain there exist a few missing as well as weak links. Ginning is considered to be one of the weakest links characterized by excessive use of energy, presence of contaminants & trash and lack of facilities for quality assessment of individual bales. Although spinning sector is performing better with modern facilities, weaving/knitting sector still needs to improve in quality and product up gradation to meet the international standards. Further, processing such as preparatory chemical treatments of yarns and fabrics, eco-friendliness, energy use efficiency, and its treatment are factors that need immediate attention. In the handloom sector, workers are exposed to harmful chemicals and environment is also vitiated with chemical effluents in rural areas. Some of these weak links have been addressed under a World Bank funded project entitled, “A Value Chain for Cotton Fibre, Seed and Stalk: An Innovation For Higher Economic Returns to Farmers and Allied Stake Holder” sanctioned by National Agricultural Innovation Project (NAIP) under Component 2 in consortium mode with Central Institute for Research on Cotton Technology (CIRCOT), Mumbai as lead centre and Central Institute for Cotton Research (CICR), Nagpur & Super Spinning Mill Ltd., Coimbatore, as consortium partners. This value chain is shown in the figure below. As regards status of research and technology in the production system, although cost and resource conservation technologies like IPM, IRM and INM have been perfected at the field level and demonstrated in several farms across the country, their benefits have not percolated to small scale growers. Also, quality seeds and inputs have remained scarce to these farmers. It is felt that an “Integrated Cultivation” approach by bringing together small holding farmers and ensuring quality inputs 532 World Cotton Research Conference on Technologies for Prosperity

at competitive price would not only bring down the cost of cultivation but also result in better quality cotton with low levels of contaminants.

CIRCOT’s Cotton Value Chain

Cotton Cl ean Cotton Bales with Ginning Production picking Fi bre Quality

Collection of Delintering of seeds Stalks & Chipping & separation to Hull Ya rn Pro duction & Kernel

Oil recovery Bio‐scouring & Linters from Kernel Dyeing with Natural Dyes

Supply to Hu ll s Co tto n seed Fabric Weav ing board Edible Bio‐ oil, seed production home making Oyster enrichment & meal & , garment fu rnishing & factory & Mushroom cattle feed edible making & Marketing Utilisation trial protein marketing

CICR with its expertise on production technologies executed this job in the current project and CIRCOT did the post harvest on-farm and off-farm management to produce clean seed cotton. For this, certified cotton seeds, fertilizers, pesticides, etc., were procured for farmers of the adopted villages near Nagpur, Coimbatore and Sirsa by CICR. Sowing and related activities were taken up along with crop growth monitoring in the farmer’s fields under supervision of CICR scientists. The integrated production technologies developed by CICR, were adopted for raising medium, long and extra-long cottons in the adopted villages. Details about cotton produced are as given below: Adopted Villages Area in Number of Quality of Seed General Sowing Period Acres Farmers Nandura & Loni villages at Nagpur 60 30 Bunny Bt In the month of June Vadapaddur village at Coimbatore 92 110 RCHB 708 Bt In the month of August Nejadela Kalan & Jhopra villages at Sirsa 82.75 34 Bioseed -6488 BG I In the month of April Kapas produced by these farmers was procured by CIRCOT under the project and was ginned in modern ginning factories in the respective area and pressed into bales. While pressing into bale, representative fibre samples were collected and evaluated using HVI. The fibre attributes so obtained were assigned to these individual bales. In the work presented here, these bales were segregated using fibre fineness and spun into yarns separately for each segregated group. Influence of fibre properties on yarn parameters is studied and reported here.

LABELING OF BALES WITH FIBRE QUALITY In this project, individual bales were tagged with their fibre properties. For spinning purpose bales were segregated in groups based on their fineness expressed as micronaire value. Yarn was manufactured in different lots from these segregated bales. This particular exercise has been carried out to study effect on yarn properties after segregation of bales based on fibre properties of the same variety of cotton.

STATISTICAL METHOD USED When yarn is manufactured from different lots of cotton bales identified on the basis of micronaire value two sources of variation may exist in yarn properties. • Between group variation, and Influence of Quality Attributes of Individual Bales on Yarn Quality 533

• Within group variation In this case each group of bales segregated on the basis of micronaire value is identified with particular code. From the lot of each code, equal numbers of yarn cones were drawn at random by using random number table. This type of sampling is called as

Representative or Stratified Sampling Number of samples to be tested was decided on the basis of coefficient of variation percentage and 95% confidence interval for the mean value. To determine whether significant variation exists or not among the yarns prepared from different groups, we decided to carry out analysis of variance (ANOVA). It is essentially an arithmetic process for portioning total sum of squares into components associated with recognized sources of variation. It has been used to advantage in all fields of research where data are measured quantitatively. In analysis of variance one finds the ratio F of two variances to be compared. In the present case variation in yarn properties among the group of bales and variation in yarn properties within the group of bales is analyzed.

The calculated F value is compared with the tabular F value for N1 and N2 degrees of freedom to decide whether to accept the null hypothesis of no difference between population means or the alternative hypothesis of a difference. The interpretation of F depends upon the particular problem, but good general rule is a) If the calculated value of F is less than the 5% probability level in tabular value, then the difference is not statistically significant. b) If the calculated value of F falls between the 5% and the 1% probability level tabular value, then there is some evidence of a difference but that this evidence by no means is conclusive. c) If the calculated value of F is greater than the 1% probability level tabular value then a real difference certainly exists.

Degrees of freedom N2 is based on total number of observations and N1 is based on total number groups. Degrees of freedom refers to independent comparison available in estimating variances.

RESULTS AND DISCUSSION Results are presented and analysed below centre wise.

Sirsa At Sirsa, Haryana Bioseed-6488 BG was used. Total 285 quintals of kapas was procured. After ginning 63 cotton bales were prepared.

TABLE 1: AVERAGE FIBRE PROPERTIES OF BALES 2.5% SL (mm) UR% Micronaire (g/inch) Tenacity (g/tex) 29.0 45 4.9 22.6 Yarn was spun to 24s count in five different groups as shown below. Each lot consisted of about eight bales amounting to approximately one and a half tonne. From each lot five yarn cones were drawn at random to test yarn properties.

TABLE 2: GROUP OF BALES SEGREGATION BASED ON MICRONAIRE A B C D E 4.7 4.8 4.9 5.0 4.7 – 5.0

534 World Cotton Research Conference on Technologies for Prosperity

TABLE 3: YARN TEST RESULTS (LEA TEST AV.) Group Count Strength CSP A 23.7 102.5 2431 B 24.1 97.2 2334 C 23.9 100.0 2388 D 23.6 106.5 2511 E 23.7 102.3 2417 Grand 23.8 101.7 2416

TABLE 4: SINGLE YARN STRENGTH TEST RESULTS Group Breaking Strength Tenacity Elongation % A 353.5 14.2 5.2 B 348.7 14.2 5.3 C 344.7 14.0 5.3 D 349.5 14.0 5.5 E 353.2 14.1 5.2 Grand 349.9 14.1 5.3

TABLE 5: USTER EVENNESS TEST RESULTS Group U% Thin Thick Neps A 13.0 20 348 253 B 13.3 19 363 294 C 12.8 15 332 261 D 12.4 11 250 209 E 12.6 13 287 216 Grand 12.6 16 316 346 F Values Within and Between (Combined)

TABLE 6: WITHIN TOTAL 25 READINGS AND BETWEEN 5 SETS OF MICRONAIRE VALUES Mic. X Lea Mic. X Mic. X Mic. X Single Mic. X Mic X Mic. X Mic. X Mic. X Mic. X Count Lea CSP Thread Str Elongation Tenacity U% thin thick neps Strength % places Places 1.14 1.99 2.21 0.23 1.23 0.2 4.05 1.44 3.39 2.23

• For D.F. N1 = 4 and N2 = 20 • F value at 5% level of significance = 2.71 • F value at 1% level of significance = 4.10 • Result indicates that there is no significant difference for yarn properties between groups for 24s count yarn after bale segregation based on fineness.

Nagpur At Nagpur, Maharashtra, Bunny Bt was used. Total 349 quintal of kapas was procured. After ginning 67 cotton bales were made ready.

TABLE 6: AVERAGE FIBRE PROPERTIES OF BALES 2.5% SL (mm) UR (%) Micronaire (g/inch) Tenacity (g/tex) 30.5 46 3.2 24.4 Yarn was spun to 30s count combed in five different groups as shown below. Each group consisted of about eight bales amounting to approximately 1.5 tonne. From each lot twenty two yarn cones were drawn in random to test yarn properties.

TABLE 7: GROUP OF BALES SEGREGATION BASED ON MICRONAIRE A B C D E 3.1 3.2 3.3 3.1-3.6 Mix

Influence of Quality Attributes of Individual Bales on Yarn Quality 535

TABLE 8: YARN TEST RESULTS (LEA TEST AV.) Group Count Strength CSP A 29.9 94.8 2836 B 30.4 91.3 2775 C 29.8 93.2 2775 D 29.7 94.4 2801 E 29.4 97.2 2858 Grand 29.9 94.2 2809

TABLE 9: SINGLE YARN STRENGTH TEST RESULTS Group Breaking Strength Tenacity Elongation % A 326.6 6.5 16.5 B 321.5 6.9 16.5 C 323.1 6.6 16.5 D 319 6.4 16.2 E 335.2 6.4 16.8 Grand 325.1 6.6 16.5

TABLE 10: USTER EVENNESS TEST RESULTS Group U% Thin Thick Neps A 11.5 6 167 298 B 11.9 9 226 330 C 12.2 11 330 571 D 12 9 256 425 E 12 5 220 407 Grand 11.9 8 240 426 F Values Within and Between (Combined)

TABLE 11: WITHIN TOTAL 110 READINGS AND BETWEEN 5 SETS OF MICRONAIRE VALUES Mic. X Lea Mic. X Lea Mic. X Mic. X Single Mic. X Mic X MicX Mic. X Mic. X Mic. X Count Strength CSP Thread STR Elongation Tenacity U% Thin Thick NEPS % places Places 7.69 8.68 4.63 4.23 2.8 1.56 8.86 7.33 19.5 19.22

• For D.F. N1 = 4 and N2 = 105 • F value at 5% level of significance = 2.45 • F value at 1% level of significance = 3.48 • Results indicate that there is significant difference between groups for 30s count yarn after bale segregation in the case of Lea Count, Lea and Single Thread Strength, Evenness of yarn and Thin places. Difference in case of Thick place and Neps is highly significant. For single yarn tenacity and breaking elongation there is no significant difference.

Coimbatore At Coimbatore, Tamilnadu, RCBH-708 Bt was used. Total 687 quintal of kapas was procured. After ginning cotton 142 bales were ready.

TABLE 12: AVERAGE FIBRE PROPERTIES OF BALES OF COIMBATORE COTTON 2.5% SL (mm) UR (%) Micronaire (g/inch) Tenacity (g/tex) 28.3 48 4.5 21.5 Yarn was spun to 80s count in seven different groups as shown below. Each group consisted of about eight bales amounting to approximately one and a half tonne. From each lot twenty yarn cones were drawn at random to test yarn properties.

536 World Cotton Research Conference on Technologies for Prosperity

TABLE 13: BALE SEGREGATION BASED ON MICRONAIRE A B C D E F G 3.2-3.6 3.6 3.7-3.8 3.4-3.8 2.9-3.0 3.1-3.2 2.9-3.2

TABLE 13: YARN TEST RESULTS (LEA TEST AV.) Group Count Strength CSP A 81.1 39.8 3228 B 81.7 36.6 2988 C 81.6 37.9 3091 D 81.2 37.9 3073 E 80.8 40.1 3238 F 81 39.8 3225 G 80.9 40 3237 Grand 81.2 38.9 3154

TABLE 14: SINGLE YARN STRENGTH TEST RESULTS Group Breaking Strength Tenacity Elongation % A 147.5 5.5 20.3 B 136.3 5.1 18.8 C 138.9 5.2 19.2 D 140.0 5.1 19.2 E 143.9 5.8 19.7 F 144.3 5.9 19.8 G 144.4 6.0 19.4 Grand 142.2 5.5 19.5

TABLE 15: USTER EVENNESS TEST RESULTS Group U% Thin Thick Neps A 11.7 30 84 262 B 12.9 88 198 415 C 12.7 80 169 373 D 12.6 69 154 301 E 12.1 48 147 367 F 12.0 35 136 313 G 12.0 38 135 310 Grand 12.3 55 146 334 F Values within and between (Combined)

TABLE 16: WITHIN TOTAL 140 READINGS AND BETWEEN 7 SETS OF MICRONAIRE VALUES Mic. X Lea Mic. X Lea Mic. X Mic. X Mic. X Mic X Mic. X Mic. X thin Mic. X Mic. X Count Strength CSP Single Elongation Tenacity U% places thick places neps Thread Str % 1.31 17.41 23.44 8.8 18.75 4.33 31.83 17.68 21.02 7.68

• For D.F.N1 = 6 and N2 = 133 • F-table value at 5% level of significance = 2.17 • F-table value at 1% level of significance = 2.96 • Results indicate that there is highly significant difference between groups for 30s count yarn after bale segregation in case of Lea Strength, Lea CSP, Single thread strength and elongation, and all the evenness properties of yarn. Even for tenacity of single yarn, difference is significant.

CONCLUSION Statistical analysis of results indicates that bale segregation based on fibre properties has significant effect on properties of yarn spun from cotton of fine and extra fine characteristics. It does not seem to have significant effect on the properties yarn spun from coarse cotton. It is therefore recommended that individual bale tagging with segregation of bales based on fineness can result in better quality yarns, leading to better quality fabrics and garments, particularly for cotton from varieties giving medium and fine fibres. 87

Development of an Automatic Roller Grooving Machine for Making Helical Grooves on Rollers Used in Roller Ginning Machines

T.S. Manojkumar1 V.G. Arude2 and S.K. Shukla2 1Programme Co-ordinator, KVK, CPCRI, Kasargod, (India) 2Scientist (Sr. Scale), Ginning Training Centre, Central Institute for Research on Cotton Technology, Amaravati Road, P.O. Wadi, Nagpur-440 023 (India) E-mail: [email protected]

Abstract—Double roller gins are the most popular ginning machines used in India. The rollers used in double roller gins become smooth due to friction between the roller and knife during continuous operation. Helical grooves are made on the rollers after every 16 to 20 working hours to make the roller surface rough to facilitate the lint to adhere to the roller at a faster rate. In the present practice of manual grooving with hacksaw, the depth, breadth and spacing of the grooves are not uniform and is a laborious process requiring an hour to groove roller. This results in lower productivity of ginning machines and damages the roller affecting its durability. To overcome these problems an automatic roller grooving machine was developed to make helical grooves on the roller. It consists of main frame, head stock, tail stock and a cutter assembly mounted on a movable trolley. The rotary motion of the roller and forward motion of the trolley was synchronized together with suitable drive mechanism. The rotary motion of the saw blade cutter was achieved with the appropriate mechanism. With this mechanism roller completes the revolution of 270o and the cutter assembly moves forward by the length of the roller. A mechanism consisting of a screw shaft and handle arrangement is used for adjusting the depth of groove. A mechanism consisting of a chuck on a spindle with an indexing arrangement is developed for making consecutive helical grooves at a specified distance parallel to each other. The rotary cutter saw blade was mounted at an angle of 170 to the roller axis on a vertical plane. The machine was successfully tested and its performance was found to be satisfactory. The machine can groove the roller in ten minutes with 18 equally spaced grooves of uniform depth and breadth of 2 mm with accuracy. The re-grooving on the same impression after reduced roller diameter was also successfully carried out. The automatic roller grooving machine can successfully replace the existing manual method of grooving and will avoid the drudgery involved in this operation.

INTRODUCTION Ginning machines are devices which separates mechanically the fibres and seed of the seed cotton. Roller gins are the most popular ginning machines used in India. Normally four types of roller gins, namely laboratory model gins, single roller (SR) gins, double roller (DR) gins, and rotary knife gins are used for ginning. The roller gins work on the principle of Ma-carthy's gin. Ginneries are presently using different materials for rollers viz., chrome composite leather, newspapers, walrus leather, rubber-canvas composite material, cotton woven fabrics, etc. Among these materials the chrome composite leather is the most widely used roller material. The roller of a given length is made of chrome composite leather washers, which are compressed at a pressure of about 14 kg/cm2 on a steel shaft. The shape of steel shaft inside the discs can be square, rectangular, pentagonal, etc. The washers are made of partly finished chrome tanned leather sheet, each 0.75 to 1.25 mm in thickness, which are glued together. Each washer consists of 10 to 20 numbers of leather flaps. The sheet is finally cut with the help of a die in circular shapes to make the washers. Individual washers are perfectly stitched with single cotton thread. Each washer is about 13 to 19 mm in thickness. The ginning roller is made by inserting required number of washers over a steel shaft. By applying optimum pressure on the inserted washers, the washers are compressed together, which forms a ginning roller. This roller is finished on a lathe machine and grooved. The surface of the chrome composite leather roller gets polished very fast while running. During the continuous operation of the DR gin, due to friction between the roller and knife, the rollers become smooth and the surface of leather roller needs to be roughened by cutting grooves to get optimum ginning output. Due to this the ginning out put of the machine drops continuously with running time. To 538 World Cotton Research Conference on Technologies for Prosperity

overcome this, the chrome leather roller is required to be removed from the machine and then the surface is roughened by cutting grooves. The surface of the roller is given a smooth finish and helical grooves of 2 mm width and depth are to be cut on it such that the spacing between the consecutive grooves is uniform throughout the length of the roller. The purpose of the groove is two-fold namely, they prevent abortive seeds and motes from sticking under the knife; and they provide place for the fibres to enter readily under the knife, assuring a constant flow of fibres over the roller, there by increasing the production. The helix makes a half to three –fourth revolution about the length of the roller. Rollers should be grooved every day before the start of the ginning or once in every 16 –20 working hours. The grooving of the rollers is necessary to increase the rough surface for the lint to adhere to the roller at a faster rate. The grooves should not be appreciably wide or distinctly V-shaped. This process is very labour intensive job and in India is done preferably manually using saws. For carrying out grooving the roller is mounted on a stand. Two men pull a saw in a reciprocating manner by standing on either side of the roller. The roller has to be rotated by hand while cutting to give a helical groove. Rotating the roller with hand while cutting is not at all uniform and hence the successive grooves cut on the roller are never parallel to each other and sometimes overlap each other. Since it is a manual operation, the uniformity in depth and width of groove can not be maintained. Some ginneries use marble cutting tool and grooving is done by rotating the roller with one hand while moving the motor along with the tool on the other hand on the surface of the roller in a helical direction. This operation is very dangerous as the motor has to be held in hand with the cutting tool rotating at very high rpm and may cause serious injury to the operator. The risk of getting electric shock also is very high which makes the grooving very risky job. In this operation also the grooves made are never parallel to each other and the depth of grooving is also varying which causes damage to the fibre during ginning. Some ginneries also use conventional grooving machines in which the roller has to be rotated by hand as well as the trolley carrying the cutting tool has to be moved in the forward direction by hand. Due to these manual operations, operator does not have any control on the forward speed and the angle of rotation of the roller which results in grooves with non uniform spacing. Also the non uniform grooving has a adverse effect on the fibre and seed quality and on the production capacity of the machines. There should not be any damage to the properties of the ginned lint and quality of seed obtained while processing in gins. Besides, maintaining the seed quality and ginning percentage, preservation of fibre properties viz. 2.5% span length, length uniformity ratio, micronaire value, tenacity are equally important for cotton. To overcome these difficulties an auto-grooving machine has been developed to make helical grooves with precise depth control and with uniform spacing between two grooves.

MATERIALS AND METHODS An auto groovier machine has been designed. The 2D and 3D drawings of the designed machine were prepared in high end software. A prototype of an autogroover machine has been developed and fabricated at Ginning Training Centre of Central Institute for Research on Cotton Technology (CIRCOT), Nagpur.

Design and Fabrication Autogroover consist of main frame, head stock, tail stock and a cutter assembly mounted on a movable trolley developed for making helical grooves on leather rollers. The rotary motion of the roller and forward motion of the trolley was synchronized together with suitable drive mechanism. The rotary motion of the saw blade cutter was achieved with the appropriate mechanism to cut precise groove on the roller. The machine is provided with an indexing mechanism for making consecutive helical grooves at a specified distance parallel to each other on the roller. Adjustments viz. change of angle of helical grove, number of grooves, distance between successive grooves, depth and width of groove, speed of roller, cutting blade and trolley could be made easily for carrying out smooth grooving of the roller. Development of an Automatic Roller Grooving Machine for Making Helical Grooves on Rollers Used in Roller Ginning 539

Base Frame The roller grooving machine base frame was designed to 2.4 m length, 0.6 m width and 0.66 m height with channel section frame of 100 x 50 mm. The frame was supported at the four corners by four legs made of the same section with the total height of the frame at 0.66 m. The head stock and tail stock were mounted on either end of the frame to hold the roller firmly in a horizontal direction parallel to the length of the frame. Two rails were provided on the top of the frame to move a cutting blade assembly consisting of a cutting tool with driving motor from one end to the other. Accurate machining was done to obtain the geometric centre of chuck fixed on the headstock and revolving centre of the tailstock concentric in one line. The rails for guiding the movement of the trolley was made with 50mm square bar fixed on the top of the main frame on either sides.

TABLE 1: SPECIFICATIONS OF THE AUTOGROOVER MACHINE S.N. Particulars Values 1 Cutter blade diameter (mm) 100 2 Cutter blade thickness (mm) 1.5 3 Cutter blade speed (rpm) 1400 4 Power required to drive cutter blade (HP) 1 5 Power required to drive the roller and trolley (HP) 1 6 Trolley size (mm x mm) 600 x 350 7 Number of groves 18 8 Overall size of the machine (m x mm x mm) 2000 x 600 x 660

Head Stock The head stock consisted of a cast iron box having size, 270 mm length, 300 mm width and 350mm height. The opposite faces were bored and fitted with a spindle having 50 mm diameter and 500 mm length. On the inner side of the spindle a 150 mm true chuck was fitted to hold the roller. On the outer side of the spindle a bevel gear was mounted on bush bearing which could be rotated independent of the chuck. The spindle and the bevel gear are locked together by an indexing mechanism. This consists of an arm fixed on the spindle perpendicular to it and having a spring loaded nail which locks it to a hole made on the bevel gear. At the same radius a total of eighteen holes are made at 200 angles apart. The bevel gear was attached to a pinion gear which is mounted on a shaft fitted vertically on the on the base frame. The movement of the chuck and the cutter assembly are synchronized for uniform forward and backward motion.

Tail Stock Screw type tail stock was made with 50 mm screw shaft and 4 TP threading attached to a square nut connected to the top sliding block. The forward and backward movement was obtained by rotating a handle attached to the screw. The roller was secured between the chuck and the tail stock horizontally for grooving by moving the tail stock towards the chuck by rotating a handle provided on the screw attached to the tailstock. Gripping of the roller is provided by tightening the chuck on the head stock.

Cutter Assembly A 600 mm X 350 mm horizontal trolley was fabricated with 45 x 45 x 5 mm L section material and mounted on 4 pulleys to slide on the rails provided on the main frame. A rotary saw blade and motor assembly was mounted assembly was mounted on a sliding spindle mounted on the trolley. This assembly could be lifted or lowered to adjust the depth of groove by rotating a wheel attached to a gear box on which a spindle is mounted. The rotary saw cutter was fixed at an angle of 17o to the direction of forward movement of the trolley. . The cutter blade was positioned exactly above the centre line of the roller. This trolley was synchronized with the rotation of the chuck. 540 World Cotton Research Conference on Technologies for Prosperity

Fig. 1: Schematic Diagram of Autogroover Machine (Front Elevation)

Fig. 2: Schematic Diagram of Autogroover Machine (Top View)

RESULTS AND DISCUSSION The performance of the autogroover machine was evaluated and the capacity, power requirement and energy consumption of the machine was studied. The machine performance was compared with the manual method of grooving. The precision and accuracy of the grooving was also noticed. The roller was mounted horizontally between chuck and revolving centre. The cutting circular saw was adjusted to just touch the roller by bringing the tool post carrier near to the chuck. Then the cutter saw was rotated by starting the motor and was slowly brought down by rotating the handle attached to the spindle of the gear box mounted on tool post carrier. By this method the depth of cut was suitably adjusted to 2 mm. Then the trolley was moved forward by starting the motor for drive assembly. As the Development of an Automatic Roller Grooving Machine for Making Helical Grooves on Rollers Used in Roller Ginning 541

trolley with cutter saw moves forward, the roller rotates in clockwise direction as it is attached to the same shaft through a pinion and a bevel gear mechanism. This way the synchronization between the forward movement of the trolley and clockwise rotation of the roller was made in such a way that when the saw cutter moves from the head stock end to the tail stock end, the roller makes a rotation of 2700. A helical groove was made on the surface of the roller when the trolley was moved forward. The indexing for making further grooves was done manually by adjusting the pin on the head stock spindle to lock with the successive holes on the bevel gear which aligns the roller de-linking from the trolley movement. A total of eighteen grooves were thus made on the roller.

Performance Evaluation The developed machine was successfully tested at Ginning Training Centre of Central Institute for Research on Cotton Technology (CIRCOT), Nagpur. The chrome composite leather rollers used in cotton ginneries were used for the trials. Roller was mounted on the autogroover machine and grooving was carried out. The necessary adjustments of indexing mechanism and the cutter assembly were carried out before starting the machine. The performance of the machine was found to be satisfactorily. The precise and accurate helical grooves were made on the roller with the help the machine. The equally spaced grooves of uniform depth and breadth of 2 mm were cut with precision and accuracy. The successive grooves at the designed spacing between two grooves were also carried out. The uniform spacing between the two successive grooves throughout the length of the roller was noticed. The re-grooving on the same impression after reduced roller diameter was also successfully carried out. The actual time required for cutting a grove was found to be 30 seconds which includes the time required for forward and return movement of the trolley. The total time required for grooving the complete roller with 18 grooves was found to be 10 minutes. Six rollers were grooved with the autogroover machine in an hour.

Fig. 3: Pictorial View of Autogroover Machine Grooving on the similar roller was carried out with conventional manual method by a saw pulled by two men. Manually it takes an hour to groove the complete roller with 18 grooves. The depth, width and spacing of the grooves were not uniform throughout the length of the roller. Non uniform spacing and improper depth and width of the groves adversely affect the fibre quality and the ginning output. The autogroover machine can successfully replace the existing manual method of grooving and will avoid the drudgery involved in this operation.

542 World Cotton Research Conference on Technologies for Prosperity

Fig. 4: Pictorial View of Manual Grooving of Leather Roller

CONCLUSION 1. Autogroover machine was designed and developed to make helical grooves on the roller used in cotton ginneries. The rotary motion of the roller and forward motion of the trolley was synchronized together with suitable drive mechanism. The rotary motion of the saw blade cutter was achieved with the appropriate mechanism. 2. The machine was successfully tested and its performance was found to be satisfactorily. The machine was found to groove the roller in ten minutes with 18 grooves on it. The equally spaced grooves of uniform depth and breadth of 2 mm were cut with precision and accuracy. 3. The re-grooving on the same impression after reduced roller diameter was also successfully carried out. 4. The autogroover machine can successfully replace the existing manual method of grooving and will avoid the drudgery involved in this operation.

REFERENCES [1] Antony, W.S., 1990. Performance characteristics of cotton ginning machinery Transactions of the ASAE, Vol. 33(4): 1089- 1097. [2] Arude V. G, 2004. Roller replacement for DR gins at appropriate time: A surer way to preserve quality and earn more. CIRCOT ginning bulletin, Vol (4) Issue (1): 2-3. [3] Arude V. G., Shukla S.K., Patil P.G., 2004. Effect of leather roller wear on ginning output in roller gins. Journal of the Indian Society for Cotton Improvement. Vol. 29 No.2: 106-115. [4] Arude V. G., Shukla S.K., Manojkumar T. S., 2008. Cotton Ginning: Technology, Trouble shooting and Maintenance. A book published by CIRCOT, (ICAR) Mumbai. PP: 1-240. [5] Lal, M.B., 2001. Role of TMC in the production of trash and contamination free cotton in India, Paper presented in National seminar on “Relevance of Ginning in the Production of trash free cotton” held at GTC of CIRCOT, Nagpur. Book of papers: 3-8. [6] Sharma, M.K., 1999. Current Scenario of Ginning Industry. Paper presented in International seminar on “Cotton and its utilisation in the 21st century” held at CIRCOT, Mumbai, Book of papers: 161-168.

The Effect of Quarantine Treatments on the Physical Properties of Cotton Fibres and Their Subsequent Textile Processing Performance

M.H.J. Van, Der Sluijs1, F. Berthold2 and V. Bulone3 1CSIRO Materials Science and Engineering, Geelong, Australia 2Innventia AB, Stockholm, Sweden 3Royal Institute of Technology (KTH), School of Biotechnology and Swedish Centre for Biomimetic Fibre Engineering, Stockholm, Sweden

Despite its declining market share of the world fibre market, cotton still remains an important fibre, not only for the textile and clothing industry but also as a valuable source of income to a large number of countries. Cotton is currently grown in over 60 countries worldwide, with around 31% exported annually for processing in textile mills. With this comes the risk of exotic pests and diseases entering a country which can seriously affect its unique environment and native flora and fauna. Quarantine thus plays a critical role to ensure that a country remains free from serious pests, weeds and diseases present in other parts of the world. Most countries that import cotton fibre insist on a phytosanitary certificate which may require that bales of cotton are treated to ensure that the consignment is free of live insects, soil and other debris. The quarantine treatments used are generally chemical (fumigation) and in some instances radiation (gamma irradiation). This paper examines the effects of these various quarantine treatments on the physical properties of cotton fibres and the subsequent effect on textile processing performance.

METHODS AND MATERIALS Standard Upland cotton and Extra Long Staple (ELS) cotton were used to determine the effect of the various quarantine treatments on the physical properties of cotton fibre. Commercially grown Australian Upland saw ginned (Sicala V2R) as well as ELS roller ginned (Pima A8) cotton grown during the 2006/07 season under commercial growing conditions and machine harvested were used for this study. The Sicala V2R cotton was grown at Trangie in the Macintyre Valley of New South Wales (NSW) and the Pima A8 was grown at Moree in the Gwydir Valley of NSW. Samples were gathered from various parts of the bales and sent for fibre testing.

FIBRE TESTING Fibre testing was carried out on the cotton fibre to determine an initial profile for comparison and is described as untreated (NT). Bale (raw fibre) samples were conditioned under standard conditions of 20°C +/-2°C and 65% +/-3% relative humidity for 24 hours as per ISO 139. The samples were then tested on an Uster Technologies 1000 High Volume Instrument (HVI), as per American Society for Testing and Materials Standard (ASTM) D5867, for Micronaire, staple length, length uniformity, staple strength and elongation (Table 1). The visual grade, based on colour (colour grade) and visible trash (leaf grade) of the fibre was determined by classification of cotton according to the United States Department of Agriculture (USDA) established standard grade boxes. Fibre fineness was determined using the CSIRO Cottonscan™ instrument, which determines fibre fineness (linear density) by measuring the length of fibre in an accurately weighed specimen of fibre snippets. Combined with an independently measured Micronaire value from the HVI, the average fibre maturity was also calculated using Lord’s empirical relationship between Micronaire, maturity ratio and fineness (Table 2). 544 World Cotton Research Conference on Technologies for Prosperity

Bale samples were also tested for nep, seed-coat neps (SCN) and short fibre content (SFC) by an Uster Technologies Advanced Fibre Information System (AFIS PRO), as per ASTM D5866 (Table 3).

QUARANTINE TREATMENTS In order to determine the effects of the various quarantine treatments on the physical fibre properties, samples were treated as per the standard methods prescribed by the Australian Quarantine and Inspection Services. Samples of cotton were subjected to irradiation and fumigation at Steritech Pty Ltd in Melbourne, Victoria. For irradiation, samples were gamma irradiated at various dosages (21, 29, 57 and 74 kGy) using the radioactive isotope Cobalt 60. Samples for fumigation were exposed to ethylene oxide (ET) at a rate of 1200g/m³ for 5 hours at a minimum temperature of 50°C. Samples subjected to fumigation by methyl bromide (MB) were treated at ISS Australia in Sydney, New South Wales, at a rate of 32g/m³ for 24 hours. Following treatment all the samples were retested on the same instruments and under the same conditions to determine their physical properties, as described earlier.

PHYSICAL ANALYSIS Physical analysis was also conducted on samples both before and after quarantine treatment in order to explain any changes in the mechanical properties of the cotton fibre. Cotton fibres (only NT and 74 kGy) (2nm Chromium coated) were imaged using a Hitachi S4300 scanning electron microscope (SEM), to detect any physical changes. Cotton samples (only NT and 21, 29, 57 & 74 kGy) were prepared for molecular weight determination of cellulose as described by Evtuguin et al. (2003). Samples (1 g) of cotton fibres from each irradiated line and the corresponding untreated controls were extracted for six hours in toluene/ethanol (2/1) using a Soxhlet extractor. Husks and impurities were removed and 200 mg of the remaining material was transferred to a beaker and mixed with 10 ml of a 10% peracetic acid solution whose pH had been preliminarily adjusted to 4.8 with NaOH. The reaction was performed for 30 minutes at 75°C and the solution cooled on ice and filtered. The cotton samples were then washed three times with 100 ml deionised water and once with 100 ml acetone/ethanol (1/1). The samples were then air dried at ambient temperature. Size-exclusion chromatography (SEC), a proven and effective technique for measuring molecular weights (MW) of cellulose, was then performed on 15 mg of each dried cellulose sample treated with peracetic acid. Cellulose was swollen in water and solvent exchanged three times with dry N, N- dimethylacetamide (DMAc) before the addition of 2.1 ml of an 8% LiCl/DMAc solution. Ethylisocyanate (0.22 ml) was then added to the mixture to fully dissolve the cellulose during 5 days incubation at room temperature. The cellulose solutions were then analysed by SEC using a 2690 Separation Module, equipped with 4 x Mini-Mix-A (20µm; 4.6 x 250 mm) columns, as described by Berthold et al. (2004).

TEXTILE PERFORMANCE In this part of the study we determined what the effects are of the various quarantine treatments (only NT, 21, 29, 57 & 74 kGy) on the textile processing performance and quality of the Upland and ELS cotton.

Moisture Regain Moisture regain was tested according to ASTM 1576. Samples were wet out in water with small amount of wetting agent, squeezed out and left to dry under standard laboratory conditions for 2 weeks prior to testing.

The Effect of Quarantine Treatments on the Physical Properties of Cotton Fibres 545

Dyeing Ten grams of each sample was put into a dyeing basket and placed in an Ahiba Turbomat dyeing machine. Samples were then scoured and dyed with Cibacron red LS6G (1%) reactive dye using a standard recipe. Upon completion, the samples were removed, hydro extracted (using a centrifuge to remove excess water) and air dried. Each sample was then put in the viewport of a Gretag Macbeth Color Eye 7000A spectrophotometer. Each sample was measured 5 times and the readings averaged.

Yarn Production In order to determine textile performance of the cotton samples, a hybrid system was used which consists of a re-furbished ‘Shirley’ miniature spinning plant manufactured by the Platt Company in the UK. This system consists of using the miniature card and draw frame to produce slivers, which are then transferred to a full-scale spinning system for further processing through a further draw frame passage and the production of roving, prior to spinning, as described by van der Sluijs et al. (2009). Draft and twist was optimized for each sample to deliver a 30 Ne carded yarn with a twist factor of αe 3.7 (792 turns per meter). One yarn bobbin per irradiation dosage was tested for quality parameters Spun yarns were conditioned under standard conditions of 20°C +/-2°C and 65% +/-3% RH for 24 hours and tested for linear density (count) as per Australian Standard (AS) 2001.2.23, twist as per AS 2001.2.14, evenness, hairiness and imperfections using an Uster Technologies 4-SX evenness tester as per ASTM D1425. Tensile properties were determined using the Uster Technologies Tensorapid 3, as per ISO 2062:2009.

Fabric Production and Dyeing After yarn testing, the left over yarns were waxed and wound but not cleared using a Schlafhorst 238RM winder. Wound yarns were then knitted on a Lawson Hemphill 25.4cm “10inch” F.A.K. circular knitting machine, using a cover factor of 1.37 to produce a fabric weight of 153 g/m2. The dyed fabric was conditioned under standard conditions of 20°C +/-2°C and 65% +/-3% RH for 24 hours and tested for mass per unit area by AS 2001.2.13, for bursting strength as per ISO 13938- 2:1999 and abrasion resistance using the Martindale instrument as per AS2001.2.25-06.

RESULTS AND DISCUSSION

Physical Results By any measure, the fibre properties of the two cottons used in this study can be considered as good quality and above the Australian base grade1. As expected, the ELS cotton had much higher bundle tenacity and was inherently finer than the Upland cotton (Table 2), which would have positively affected the bundle tenacity result.

1* TABLE 1: FIBRE RESULTS BY THE HVI 1000 AND VISUAL GRADE Variety Tenacity Elongation Length SFI UI Micronaire Visual g/tex % Inch % % µg/Inch Grade Upland 29.8 6.1 1.161 9.1 82 4.08 11~3 ELS 44.5 6.4 1.358 5.9 86 4.01 1 1Calibrated using HVI ICC Upland and Pima Calibration Cottons * Average of 10 tests

2 TABLE 2: FINENESS BY COTTONSCAN™ AND CALCULATED MATURITY RESULTS Variety Fineness (MTEX) Maturity Ratio Upland 187 0.71 ELS 167 0.75 2Average of 5 Tests

1Australian Upland base grade quality is staple length > 1.130 inch, strength > 29 g/tex and Micronaire in the range of 3.5-4.9. ELS base grade quality is staple length > 1.350 inch, strength > 44 g/tex and Micronaire in the range of 3.5-4.1. 546 World Cotton Research Conference on Technologies for Prosperity

3 TABLE 3: NEP, SEED-COAT NEP AND SFC RESULTS BY THE AFIS PRO Variety Neps/ gram SCN/ gram SFC(w)% Upland 326 21 8.9 ELS 167 10 2.9 3Average of 5 Tests The average results after the various quarantine treatments are shown in Figures 1 to 3, expressed with y-error bars of one standard deviation, giving an indication of the variation. The fumigation treatments by either MB or ET had little or no significant effect on the physical properties of the cotton fibre. However gamma irradiation, even at the lower dosages, has an effect on the physical properties of the fibre, with these effects becoming more apparent and significant as the dosage strength increased. In the case of Upland cotton, the strength of the fibre reduced significantly after gamma irradiation of 21 kGy, with the fibre strength significantly reducing with each dosage. Corresponding with the decrease in fibre strength was a gradual, but significant decrease in fibre elongation with each dosage. In the case of the ELS cotton, the strength was affected more significantly than for the Upland cotton, reducing by almost 5 g/tex (11%) from 44.5 g/tex to 39.4 g/tex after gamma irradiation of 21 kGy. With each subsequent radiation dosage, the fibre strength was significantly affected. This decrease in fibre strength corresponded with a gradual but significant decrease in fibre elongation, although the elongation did increase at a dosage of 21 and 74 kGy. Notwithstanding this anomaly, there was a significant decrease in elongation with a dosage of 29 kGy and 57 kGy. The extent of the decrease in fibre strength and elongation due to the various quarantine treatments is graphically illustrated in Figures 1 and 2.

Fig. 1: Effect of Quarantine Treatments on Fibre Strength

Fig. 2: Effect of Quarantine Treatments on Fibre Elongation The Effect of Quarantine Treatments on the Physical Properties of Cotton Fibres 547

For both the Upland and ELS cotton, Micronaire, maturity, fibre fineness and nep content values were not affected by gamma irradiation. Fibre length was also not significantly affected; however, the short fibre index (SFI)2 increased significantly at the 29 kGy dosage, gradually increasing with subsequent higher dosages. This trend was also noted in the short fibre content %, by weight, as determined by the AFIS PRO. This in turn also had an effect on length uniformity which also tended to decrease at the 29 kGy dosage, with Upland cotton decreasing from 82 to 80% and the ELS cotton decreasing from 86% to 83% with subsequent higher dosages. There was a slight impact on the colour of the Upland cotton, although the effect was minimal as the colour deteriorated from Good Middling White (11~3) to Good Middling Light Spotted (12~1) to Spotted Good Middling (13~3) cotton as the gamma irradiation dosages increased. There was no impact on the colour of the cotton as Pima cotton is naturally creamier than Upland cotton and gamma irradiation did not seem to make any difference to the colour. The extent of the increase in SFI due to the various quarantine treatments is graphically illustrated in Figure 3.

Fig. 3: Effect of Quarantine Treatments on Short Fibre Index %

STRUCTURAL ANALYSIS OF IRRADIATED COTTON SAMPLES In order to determine the reason for the significant changes in the physical fibre properties after gamma irradiation, the samples were analysed by a range of techniques including SEM, and SEC molecular weight determination. As can be seen by the SEM images shown in Figure 4, no significant differences to the surface of the fibres were found between the untreated and treated samples.

2 The proportion by mass of fibres shorter than one half inch, measured by the HVI. 548 World Cotton Research Conference on Technologies for Prosperity

Fig. 4: Representative SEM Images of Untreated (Left) and 74 kGy Irradiated (Right) Cotton: Top Upland; Bottom ELS Cotton

DETERMINATION OF CELLULOSE MOLECULAR WEIGHT The estimated Molecular weight (MW) of the non irradiated cellulose samples was 106 Da for the ELS cotton, while the Upland cotton exhibited a significantly lower apparent MW (7 x 105 Da) (Figure 5).

Fig. 5: Estimated Molecular Weight of Cellulose from Untreated and Gamma Irradiated Cotton Fibre These MW correspond to a degree of polymerization (DP) of ca 6200 for the ELS and 4300 for the Upland cotton. This difference may reflect genetic variation or different growth conditions, although such parameters have never been reported to affect the MW of cellulose from different cotton lines. Thus, the actual reason for the observed differences remains unclear. The observed apparent MW dropped for all lines from their original value (106 or 7 x 105 Da) to ca 2.5 - 3 x 105 Da under a dose of 21 kGy. Higher irradiation doses were accompanied by a continued decrease in MW, but the observed decrease was more progressive than that observed between the non irradiated samples and those exposed to 21 kGy. The apparent MW of all cellulose samples decreased from 2.5 - 3 x 105 Da to 105 Da when exposed to a total irradiation dose of 74 kGy. These results suggest that a 21 kGy irradiation dose provokes the breakage of cellulose chains at the most sensitive points probably representing domains of lower crystallinity in the fibrillar structures, while higher doses are required to further decrease the size of cellulose chains from the more crystalline domains of the fibres. The decrease in molecular size is most likely responsible for the observed alteration of the mechanical properties of the cotton fibres upon irradiation. Similar to our data, samples from wood have been shown to exhibit a decreased molecular weight upon increasing irradiation doses compared to the untreated samples, while the degree of crystallinity of the cellulose fibres is not significantly modified upon irradiation (Aoki et al. 1977).

The Effect of Quarantine Treatments on the Physical Properties of Cotton Fibres 549

TEXTILE PERFORMANCE

Moisture Regain Figure 6 shows the moisture regain of the untreated and treated fibre samples. It is interesting to note that fumigation with either MB or ET has a significant effect on the moisture regain of both the Upland and ELS cotton fibre. Irradiation with a 21 kGy dosage gives similar results with the moisture regain steadily decreasing as the dosage increases to 57 kGy, after which the moisture regain does not significantly change.

Fig. 6: Moisture Regain of Upland and ELS Cotton Fibre at Various Quarantine Treatments

Dyeing Figure 7 shows a photograph of the untreated and treated fibre samples after dyeing. The differences in shade and hence dye uptake is clearly visible. As the irradiation dosages increase, the dye uptake decreases and hence the shade of the samples decrease.

Fig. 7: Dye Uptake of Untreated and Treated Cotton Fibre at Various Quarantine Treatments 550 World Cotton Research Conference on Technologies for Prosperity

Each sample was then put in the viewport of a Gretag Macbeth Color Eye 7000A spectrophotometer. Each sample was measured 5 times and the readings averaged. The appearance of dyed fibre samples were measured using the CIELAB colour scale, using L (lightness), a (redness) and b (blueness). Differences between the samples were assessed in terms of delta E (∆E), which it the total colour difference from the untreated fibre samples and takes into account differences in L, a and b. Delta E values near or greateer than one between the untreated and treated samples were deemed as being significant on the basis of the monochromatic nature of the dyed samples.

TABLE 4: FIBRE APPEARANCE REPORTED IN LIGHTNESS (L), REDNESS (A), BLUENESS (B), AND ∆E Upland L* a* b* ∆E NT 49.05 54.19 20.16 0 MB -4.34 -0.47 0.26 2.0 ET -2.20 -0.61 -0.53 1.07 21 -3.38 -3.97 -4.05 2.9 29 1.27 -3.86 -4.55 2.7 57 1.77 -4.85 -5.13 3.2 74 5.74 -7.71 -6.95 5.1 ELS L* a* b* ∆E NT 48.10 52.51 20.08 0 MB 1.35 0.36 -3.17 0.78 ET -1.27 1.23 1.68 1.13 21 4.52 -1.75 -3.17 2.8 29 3.71 -3.36 -3.59 2.8 57 7.46 -5.95 -6.09 5.1 74 7.88 -7.83 -7.04 5.8

Yarn Results There were no significant differences in the evenness and imperfection values between the untreated and treated fibre samples. However, as can be seen in Figure 8, the yarn strength significantly decreases as the irradiation dosage strength increases, with the results typically following the fibre strength and elongation results. The yarn strength, for both the Upland and ELS cotton yarns, did not reduce significantly from the NT cotton and the 21 kGy irradiated cotton. However, there was a significant reduction in yarn strength with an irradiation dosage of 29 kGy, which would make the Upland cotton yarn impossible to process into fabric by the weaving and also the knitting processes. With an irradiation dosage of 57 and 74 kGy the yarn strength decreased even further to below 10 cN/tex. In the case of the ELS cotton, the yarn strength reduced to 18.7cN/tex, which would make processing of fabric on high speed weaving impossible. The yarn strength was further reduced to 14.8 cN/tex with irradiation dosages of 57 kGy and 74 kGy.

Fig. 8: Yarn Strength of Untreated and Treated Cotton The Effect of Quarantine Treatments on the Physical Properties of Cotton Fibres 551

As can be seen in Figure 9, this decrease in yarn strength coincided with a gradual decrease in yarn elongation. As was the case with the yarn strength, there was no significant difference in yarn elongation between NT, Upland and ELS cotton and the 21 kGy irradiated cotton. There was however a significant reduction in yarn elongation between NT Upland and ELS cotton and the 29 kGy irradiated cotton. In the case of the Upland cotton, the yarn elongation at 57 kGy was similar to the results of the 29 kGy dosage and a dosage of 74 kGy almost reduced the yarn elongation by half when compared to NT cotton (6.6% to 3.7%). In the case of the ELS cotton, the yarn elongation continued to steadily drop with each dosage.

Fig. 9: Yarn Elongation of Untreated and Treated Cotton

Fabric Results As can be seen in Figure 10, the fabric bursting strength significantly decreases as the dosage strength increases, indicating that the fabric strength decreases as the irradiation dosages increases, typically following the yarn strength results in Figure 1. Fabrics became significantly weaker with each higher irradiation dosage. Foor both the Upland and ELS cotton, there was a significant decrease in fabric strength with a dosage of 21 kGy. The fabric strength continues to decrease with the higher dosages but, although significant, the reduction in strength was not as large as between the NT and the 21 kGy dosage.

Fig. 10: Fabric Bursting Strength of the Untreated (NT) and Treated Cotton The abrasion resistance was determined only for NT and 74 kGy irradiated fabrics. The results show that abrasion resistance of both the Upland and ELS cotton was significantly affected, both failing at 5- 6000 rubs as compared to NT cotton failing at ~ 50 000 rubs.

CONCLUSION The fumigation treatments by either ethylene oxide or methyl bromide had little or no significant effect on the physical properties of the cotton fibre. However gamma irradiation, even at the lower dosages, did have an effect on the physical properties of the fibre, with these effects becoming more apparent and 552 World Cotton Research Conference on Technologies for Prosperity

significant as the dosage strength increased. Our results show that the physical fibre properties of the cotton such as; strength, elongation, length uniformity, short fibre and to a lesser extent length and colour are affected by gamma irradiation. Moisture regain and dye uptake were also significantly affected. In addition, there were differences between the Upland and ELS cotton varieties. Analysis by various microscopy methods revealed no noticeable surface damage. However, the apparent molecular weight of the cellulose present in cotton fibre decreased even at low gamma irradiation dosage (21 kGy), irrespective of variety. The decrease in molecular size is in all likelihood responsible for the changes in the physical properties of the cotton fibers upon irradiation. From a textile processing performance point of view, yarn results show that the various irradiation dosages did not have a significant impact on the evenness and imperfection values. However, gamma irradiation had a significant effect on the yarn strength and elongation results of both the Upland and ELS cotton, with the results typically following the fibre strength and elongation results. The fabric results also show that gamma irradiation does have a significant effect on fabric strength and abrasion resistance for both the Upland and ELS cotton, with the results typically following the yarn strength results. The salient message from this study is that if any cotton lint needs to be treated by quarantine one must insist on chemical (fumigation) by either ethylene oxide or methyl bromide as gamma irradiation, even at low dosages, severely damages the physical properties of cotton lint. These physical damages can cause major issues if the cotton lint is to be used to either calibrate fibre testing instruments, to benchmark various cottons or for commercial processing.

ACKNOWLEDGEMENT The authors gratefully acknowledge the financial support of the Cotton Research and Development Corporation and CSIRO Materials Science and Engineering. They also acknowledge the assistance of Jeff Church, Colin Veitch and Bernadette Lipson in compiling this report. The support of Steritech and the Auscott Classing facility is also acknowledged. The authors also acknowledge the assistance of Fred Horne, Mark Freijah, Phil Henry, Lisa O’ Brien, Peter Herwig and Colin Brackley for processing the fibre through to fabric as well as Susan Miller and Liz Coles for testing the samples.

REFERENCES [1] Aoki, T., Norimoto, M. and Yamada. T., (1977) ‘Some Physical Properties of Wood and Cellulose Irradiated with Gamma Rays’. Wood Res. 62, pg 19–28F. [2] Berhold, F., Gustavsson, K., Berggren, R., Sjöholm, E. and Lindström, M., (2004) ‘Dissolution of Softwood Kraft Pulps by Direct derivatization in Lithium Chloride/ N, N-Dimetylacetamide’. J. Appl. Polym. Sci., 94: 424–431 [3] Evtuguin, D.V. Tomas, J.L. Silva, A.M.S and Neto, C.P. (2003) ‘Characterization of an acetylated heteroxylane from Eucalyptus globulus Labill’. Carbohydr. Res. 338: 597–604. [4] Lord, E., (1956) ‘Airflow through plugs of textile fibres. Part II. The Micronaire Test of Cotton’. J. Text. Inst. 47: T16 – T47 [5] International Cotton Advisory Committee, (2010) ‘Cotton: World Statistics’. [6] Van Der Sluijs, M.H.J, Long, R. and Gordon, S., (2009) ‘An Alternative Miniature Cotton Spinning System’, Beltwide Cotton Conference, pg 1446–1452 89

The Impact of Cotton Fibre Maturity on Dye Uptake & Low Stress Mechanical Properties of the Fabric

S. Venkatakrishnan and R.P. Nachane CIRCOT, Coimbatore

Abstract—In the Present study True Maturity has been evaluated in Premier ART-2, after testing with reference standard Maturity Samples, supplied by the instrument manufacturer, whose maturity values measured and labeled using Image processing technology from the renowned FASER INSTITUT, Bremen, Germany and the line of best fit for Maturity values has been observed in ART-2 and the linear regressed line is 99%, which indicates the measurement principle is an excellent way of measuring Maturity. Further In the present study, in order to know the impact of cotton fibre Maturity on Dye uptake and low stress mechanical properties, two groups of cotton samples has been collected (long staple with 33mm and extra long staple with 36mm), from different growth areas in order to have broad ranges of Maturity.The above groups of cotton is tested in PREMIER ART 2 instrument for True Maturity. Yarn and knitted samples were produced from each cotton sample and all the process parameters for producing such samples were kept constant. The k/s value of grey and dyed fabrics produced from different growth regions of cotton sample dye differently due to the differences in Maturity. The knitted fabric produced from the yarn, spun from high matured cotton showed higher compressional recovery, tensile resilience and smoother surface compared to the fabric produced from the yarn spun from low matured cotton samples.

OBJECTIVES This research paper deal with the newly introduced fibre parameter called “True Maturity” measurement from PREMIER ART 2 Cotton Fibre Testing Instrument. The objective of the research paper is to find out • Traceability and co relation of True Maturity measurement. • Repeatability of the instrument • Usefulness of TRUE MATURITY from PREMIER ART 2 on dye uptake and low stress mechanical properties.

MATERIALS AND METHODS

Traceability The 4 reference materials used are namely RSM 1, 2,3 and 4 having the maturity values measured and labeled using Image processing technology from the renowned FASER INSTITUT, Bremen, Germany and supplied by the instrument manufacturer. These materials cover the wide range of maturity values from 0.72 to 1.06

Repeatability of the Instrument The reference materials from FASER INSTITUT, Germany (namely RSM 1, 2,3 and 4) were tested in PREMIER ART 2 for True Maturity measurement on various days to ascertain the REPEATABILITY of the instrument.

554 World Cotton Research Conference on Technologies for Prosperity

Usefulness of True Maturity from Premier Art 2 on Dye Uptake and Low Stress Mechanical Properties In order to find out the impact of True Maturity values on fabric properties, two groups of samples were prepared. First group containing 4 cottons of long staple variety with staple length of about 33mm and second group containing 2 cottons of extra long staple variety with staple length of about 36mm. All cottons were taken from different growth areas which cover a wide range of maturity values. The above groups of cottons were tested in PREMIER ART 2 for True Maturity values. Yarn and knitted samples were produced from each cotton sample and all the process parameters for producing such samples were kept constant. The differences in k/s value between samples of each group were analysed. Also the low stress mechanical properties of each cotton sample were tested using KAWABATA evaluation system.

IMPORTANCE OF MATURITY The world wide expansion of cotton market has opened up wider possibilities for the spinning Mills to select cotton and it helped in reducing cost and improving quality and at the same time this situation has also imposed new challenges for the cotton buyers. Earlier cotton purchase was restricted to well established varieties and growing regions, so by controlling micronaire of the cotton, the dyeing and finishing problems were controlled to some extent. In recent years, there were lot of dyeing related problems witnessed and is evident from the rejection of 100% cotton knitted fabrics and it easily wipe out any savings in raw material costs obtained by purchasing different varieties / hybrids of cotton from several growth regions within the country. Unfortunately cotton with similar Micronaire that have procured from different growing regions and seed varieties/ hybrids, dye differently mainly due to the differences in Maturity of the fibre. Earlier studies reported that, the presence of excessive immature fibres in a sample is undesirable as this causes excessive waste in processing, lapping of fibres on rollers, lowering of appearance grade due to formation of neps, uneven dyeing, etc (1,2,3). In 100 % cotton, the cause of “Fabric Barre” is associated with raw material, yarn count, twist variation and hairiness arises during the preparation process in the spinning Mill. The following pie chart shows the % influence of each parameter in relation to the dyeing defects particularly “Fabric Barrre”.

The Fibre Properties that have major influence in the causes of “barre” are Fineness, Maturity and Fluorescence. Therefore it is essential for the Spinning Mill to control the above mentioned fibre properties in the lay down to get consistent dyeing and finishing of knitted fabric. Many Mills have some type of system to categorize the cotton bales in an effort to control the average Micronaire, and this is not enough to control to eliminate the “Barre”, especially in Knitted Fabric. Micronaire can be used successfully to control “Barre”, if the cotton being processed is from same variety and growth regions, but generally it never happens in a Mill. If many cotton varieties or growing areas are being mixed together, then additional testing and Maturity information is necessary. The Impact of Cotton Fibre Maturity on Dye Uptake & Low Stress Mechanical 555

Maturity: Literally, cotton fibre maturity is defined based on the cell wall thickness of the fibre. If the fibre wall is thicker and the hollow portion called lumen is very thin, then the fibre is called as Matured Fibre. On contrary, if the fibre wall is very thin and the hollow portion is very large then the fibre is treated as Immatured Fibre. Any fibre lying between these two limits can be treated as Half Matured.

COTTON FIBRE MATURITY–MEASUREMENT METHODOLOGIES The following are the most important methodologies available at present for measuring cotton fibre maturity.

Direct Method of Measurement • Caustic soda swelling method • Polarized light method • Image based cross section measurement Direct measurement involve direct estimation of cotton maturity, In case of sodium hydroxide swelling technique, the cotton fibres are immersed in NaOH and the appearance of fibres are analysed. Ribbon like fibres and convoluted fibres are treated as Immatured fibres and rod like fibres are treated as Matured fibres. In India, three methods have been recognized as standard for the determination of Maturity using of cotton fibres by Caustic soda technique (4). Method I is followed at CIRCOT. Method II is based on the ASTM (5) and Method III on the British standards (6) In case of Polarized light technique, the classification of Maturity is made depending upon the interference colours produced by the fibres (7, 8). Image based maturity is the globally accepted methodology of measuring maturity since it is most accurate and free from human errors. In image based maturity measurement, the cross section of the fibre is analysed to determine Maturity values. The cross- section of a cotton fibre contains measurable information directly related to to fibre Maturity. Much research has been conducted using the image analysis technology to measure cotton Maturity and other parameters from cotton fibre cross-sections (9, 10, and 11).

Indirect Method of Measurement Double compression methods used in High Volume Instruments manufactured by reputed firms are one of the indirect methods of measuring maturity. In spite of the importance of maturity, there is no direct or indirect measurement method that is both fast and reliable. The lack of standards of reference for maturity has made it impossible to calibrate the existing instruments (airflow instruments with double compression), further it can’t be refined without the reference standard for Maturity. In the present study, the PREMIER ART-2, Instrument has been tested with reference samples supplied by the instrument manufacturer, whose maturity values are determined by image analysis technology at Bremen Institute.

TRACEABILITY AND REPEATABILITY PREMIER ART 2 cotton testing instrument was tested using the following, four different Reference standard maturity cotton samples.

TABLE 1: MICRONAIRE AND MATURITY COMBINATION OF REFERENCE STANDARD COTTON SAMPLE High Maturity RSM 3 RSM 4 Maturity: 0.95 Maturity: 1.06 Micronaire: 3.20 Micronaire: 4.02 Low Maturity RSM 1 RSM 2 Maturity: 0.72 Maturity: 0.81 Micronaire: 2.76 Micronaire: 3.48 Low Micronaire High Micronaire 556 World Cotton Research Conference on Technologies for Prosperity

Maturity Testing has been carried out using the four reference standard cotton supplied by instrument manufacturer and the line of best fit for MR values measured in PREMIER ART 2 is shown in Fig.1. The correlation coefficient (R) is 0.9909, which indicates the measurement principle is an excellent way of measuring maturity. To determine the between days repeatability, 10 readings were taken from each sample in a subset of the reference standard cottons and calculated the Mean and standard deviation for 5 days. It appeared that SD is lower for higher Maturity samples. The reference sample RSM-1 and RSM-2 showed a standard deviation of 0.02 between readings, where as RSM-3 and RSM-4 showed a standard deviation of 0.01(shown in Fig.2) The following Figures show the correlation of True Maturity values forr cottons measured in PREMIER ART 2 and their standard values measured using image analysis technology.

Fig. 2

Fig. 3

DETAILS OF MATERIALS USED In the present study, in order to know the influence of maturity on finished fabric, we have collected two groups of cotton samples (long staple with 33mm and extra long staple with 36mm), from different growth areas in order to have broad ranges of maturity.The above groups of cottons is tested in PREMIER ART 2 instrument for True Maturity. Samples are tested by two operators separately and each operator carried out 10 tests and the average of two results given by the operator will be taken and reported in Table-1, given below: The Impact of Cotton Fibre Maturity on Dye Uptake & Low Stress Mechanical 557

TABLE 1: MEASURED FIBRE PROPERTIES OF LONG AND EXTRA LONG STAPLE COTTON USED IN THE PRESENT STUDY Group Sample ID 2.5% Span Length Micronnaire True Maturity Long Staple X 32 to 33 mm 2.9 0.77 Y 2.9 0.82 Extra Long Staple A 36 to 38 mm 3.5 0.87 B 3.5 0.78 C 3.7 0.79 D 3.7 0.83

KNITTING AND DYEING X and Y samples having a Mic value of 2.9 and having two different maturity values are spun separately for 40s Ne using a miniature spinning system. Yarn samples from each group were knitted with a cover factor of 1.32 and tightness factor of 15.4 on a standard knitting machine. Fibre, Yarn and knitted fabrics obtained from these two samples of this group are scoured and then dyed with reactive dye with 0.5% shade. Colour measurements were taken on grey and dyed fabric using D65 source at 100 observers in a standard colour measuring instrument. The grey fabrics obtained from X and Y samples are tested for low stress mechanical properties viz. compression, tensile and shear properties in KAWABATA evaluation system. In the second group of extra long staple cotton, four different samples A, B, C and D having different Micronaire and Maturity values, are spun separately for 60s Ne using a miniature spinning system. Yarn samples are knitted with a cover factor of 1.32 and tightness factor of 15.4 on a standard knitting machine. Fibre, Yarn and knitted fabrics obtained are then scoured and dyed with reactive dyes at 0.5% shade. Colour measurements were taken for grey and dyed fabrics using D65 source at 100 observers in a standard colour measuring instrument.

RESULTS AND DISCUSSIONS

Influence of Fibre Maturity on the K/ S Value of Dyed Fabric Made from “X” and “Y” Cotton Samples

Fig. 3a: K/S Vs. Wave Length for Sample X and Sample Y at Grey Stage Fig. 3b: K/S Vs. Wave Length for Sample X and Sample Y at Dyed Stage

In the present study, it has been observed that there is a difference in dye uptake and shade variation between X and Y samples even though the Micronnaire values are same. The only difference between the samples is that the X and Y samples are prepared from cotton having different True Maturity values. The K/S values of grey and dyed fabrics are shown in Figure 3 and 4. The shift in K/S value is mainly due to the difference in maturity values. So it is essential for a mill to control and maintain the maturity for each lot to control shade variations apart from micronaire.

558 World Cotton Research Conference on Technologies for Prosperity

Influence of Fibre Maturity on the Low Stress Mechanical Properties of the Grey Fabric Made from “X” and “Y” Cotton Samples The Low stress mechanical properties evaluated in KAWABATA system are shown in Table-2, and It has been clearly observed that, there is a 17 % increase in compression recovery of the fabric Y made from high matured fibre compared to fabric X, which is made from low matured fibre. The fabric made from high matured fibre “Y” showed higher flexibility than the fabric made from low matured fibres “X”. The fabric Y exhibited much smoother surface than the fabric X as is evident from the higher rating of Numeri (6.06). This was a result of lower values of geometrical roughness SMD (4.76) and the variation in the coefficient of friction MMD. No significant difference was observed in the fullness (Fukurami) between the two fabrics. The fabric Y showed higher extensibility EMT (24.2%) and higher resiliency (41.3%) to tensile deformation compared to fabric X. By virtue of higher Numeri and lower Koshi, the overall rating of fabric Y as knitted inner wear garment was higher than fabric X.

TABLE 2: LOW STRESS MECHANICAL PROPERTIES OF FABRICS X AND Y MEASURED IN KAWABATA EVALUATION SYSTEM KAWABATA property Fabric X Fabric Y Compression Recovery (RC %) 44.91 52.54 Extensibility (EMT %) 21.88 24.20 Tensile Resiliency (RT %) 36.99 41.34 Geometrical roughness (SMD) in μm 10.33 4.76 Coefficient of friction (MMD) 0.02 0.01 Koshi 6.23 5.39 Numeri 4.21 6.06 Fukurami 5.72 5.50 Total Hand Value 3.24 3.39

Influence of Fibre Maturity on the K/S Value of Dyed Fabric Made from Extra Long Staple Cotton “A”,“B”, “C” & “D” Samples Similar difference has been observed in dye uptake and shade variation among the extra long staple samples A, B, C and D. The K/S values of grey and dyed fabrics of A&B, A&C, A&D, B&C, B&D, C&D are shown separately in Figure 4.

Fig. 4 (Contd.)… The Impact of Cotton Fibre Maturity on Dye Uptake & Low Stress Mechanical 559

…Fig. 4 Contd.

Fig. 4: K/S vs. Wave Length Graph for Samples A, B, C and D by Comparing between each Other The wide difference in True Maturity value of cotton (0.09) in the samples “A”& “B” and (0.08) for the samples “A” & “C” are highly reflected in the K/S value. In “B”& “C” samples, there is not much difference in True Maturity value even though there is a slight difference in Micronnaire and we don’t find any significant difference in K/S values. It clearly indicates that dye uptake depends more on the True Maturity of cotton than Micronaire. In case of C & D Samples, It has been clearly observed that there is no difference in k/s values of grey and dyed fabric, since micronaire and maturity are controlled within the limit. 560 World Cotton Research Conference on Technologies for Prosperity

CONCLUSION • The True Maturity measurement obtained from PREMIER ART 2 are traceable to image analysis based maturity values measured at internationally recognized FASER INSTITUT located at Bremen, Germany. The Repeatability of True Maturity measurement verified and is within the acceptable limit. • Cotton with similar Micronaire,which are produced from different growing regions and seed varieties/ hybrids have varying dye uptake mainly due to the differences in Maturity of the fibre. Such Maturity variations reflected clearly in True Maturity values measured by the instrument. • Knitted Samples produced from different maturity values show clearly the dye uptake differences. Such differences correlate well with the True Maturity values provided by the ART 2 Fibre testing instrument and also, the low stress mechanical properties measured in KAWABATA evaluation system clearly correlates well with the True Maturity values of those samples. • Yarn spun from high matured cotton can be preferred to produce wrinkle free fabric and garments, as is evident from the low stress mechanical properties. • It is essential for a Spinning Mill, to control and maintain the maturity of cotton in each lay down to control shade variations in the finished fabric apart from micronaire.

ACKNOWLEDGEMENT Thanks are due to Mr.M.Sampath Kumaar, Research Assistant, CIRCOT, Coimbatore, for evaluating the fibre properties in ART-2 instrument.

REFERENCES [1] Gulati, A.N., and Ahmad, N., J.Text. Inst., 26, T26191935) [2] Gulati, A.N., Indian Text. J., 60,65,140(1949) [3] Smith, B., Text.Res.J., 61, 137 (1991) [4] “IS 236-1968: Determination of CottonFibre Maturity ( by sodium hydroxide swelling method)” ISI Hand book of Textile Testing, Bureau of Indian Standards, New Delhi, 1982 Edn., P.86 [5] “ASTM Designation: D 1442–93. Standard Test Method for Maturity of Cotton Fibres (Sodium hydroxide Swelling and Polarized Light Procedures)” 1998 Annual Book of ASTM standards, Vol.07.01., p 377. [6] BS 3085–1968: Determination of Cotton Fibre Maturity (Estimation by Classifications of Fibres swollen in Sodium hydroxide Solution)”, BS Handbook, No.11, Methods of Tests for Textiles, British Standards Institution, London, 1974 Edn.,p.2/44. [7] Schwarz, E.R. and Hotte, G.H., Text. Res. J., 5, 370(1935) [8] Schwarz, E.R., and Shapiro, L., Rayon Textile Monthly, 19, 371, 421, 480, 570(1938) [9] Thibodeaux, D.P and evans, J.P., Cotton fibre Maturity by Image Analysis, Textile Res.J., 56, 130–139, 1986 [10] Xu, B., Pourdeyhimi, B. and Sobus, J., Fibre cross-sectional shape Analysis Using Imaging Techniques, Textile Research Journal, 63, 717–730,1993 [11] Xu, B. and Ting, Y., Fibre Image Analysis, Part I: Fibre Image Enhancement, J. of Textile Institute, 87, 274–283, 1996. 90

Exploration of Residual Hazardous Compounds on Cotton Fibers

Syed Zameer Ul Hassan and Jiri Militky Dept. of Textile Materials, Technical University of Liberec, Czech Republic

Abstract—A new method based on measurement of bio-electrical signals caused by enzymatic inhibition of acetylcholinesterase (AChE) has been performed in this study for the detection of organophosphorous pesticides and carbamates being the strong inhibitor of AChE and prevents its normal function of the rapid removal of acetylcholine (Ach). Biosensor Toxicity Analyzer (BTA) equipped with electrochemical sensors was used for the testing and enzyme activity was determined by acetylthiocholine chloride (ATCCl) as enzyme substrate. The monitoring of changes in bio- electrical signals caused by the interaction of biological substances and residues were evaluated. Two samples of cotton Giza 86 from Egypt of the crop 2009/2010 were analyzed. One of them was the classical conventional cotton and the other was organic cotton without utilizing the synthetic pesticides. Cryogenic homogenization was carried out for sample pretreatment and Soxhlet extraction method (SOX) was used with two different solvents; hexane and dichloromethane for both of the samples, respectively. The resulted extracts were concentrated and then injected in the BTA and the results were also compared with Gas Chromatography equipped with mass spectrometry (GC-MS). Keywords: Acetylcholinesterase, Acetylcholine, Acetylthiocholine chloride, Biosensor Toxicity Analyzer, Cryogenic homogenization, Soxhlet extraction method, Gas Chromatography.

INTRODUCTION Cotton is the most important natural textile fiber in the world, used to produce apparel, home furnishings and industrial products (Philip J. Wakelyn, 2007). Cotton has always been a major part of the textile industry and today provides almost 38% of the world textile consumption, second only to polyester, which recently took the lead (MYERS, 1999). Cotton production is highly technical and difficult because of pest pressures and environment, e.g. drought, temperature and soil nutritional conditions. The total area dedicated to cotton production accounts approximately 2.4% of arable land globally and cotton accounts for an estimated 16% of the world’s pesticide consumption (Blackburn R.S, 2009). Pesticides are widely used for the control of weeds, diseases, and pests all over the world, mainly since after Second World War, with the discovery of some organic compounds with good insecticide or herbicide activity. At present, around 2.5 million tons of pesticides are used annually and the number of registered active substances is higher than 500 (Turiel Esther, 2008). Excessive use of pesticides causes severe environmental degradation and research efforts are being made all over the world to find alternatives for these harmful chemicals (El-Nagar, 2004). Humans can be exposed to pesticides by direct or indirect means. Direct or primary exposure normally occurs during the application of these compounds and indirect or secondary exposure can take place through the environment or the ingestion of food (Turiel Esther, 2008). This is why development of natural biological methods of insect control was initiated. Cotton grown without the use of any synthetically compounded chemicals (i.e. pesticides, fertilizers, defoliants, etc.) is considered as ‘‘organic’’ cotton. It is produced under a system of production and processing that seeks to maintain soil fertility and the ecological environment of the crop (S. Gordon, 2007). Pesticides are toxic compounds that may cause adverse effects on the human and the environment. Benzoylureas, carbamates, organophosphorous compounds, pyrethroids, sulfonylureas and triazines are the most important groups (Alder Lutz, 2006). Organophosphorous pesticides (OP) are a class of compounds that includes derivatives of phosphoric, phosphorous, thiono-phosphoric, and thion-thiolo phosporic acids esterified with methyl or ethyl and different alcohol groups (Muccio, A.D, 2006). Organophosphorous (OP) compounds are among the most toxic substances and are thus commonly used as pesticides, insecticides and chemical warfare agents (Deo, 2005). The organophosphates and 562 World Cotton Research Conference on Technologies for Prosperity carbamates are powerful inhibitors of acetylcholinesterase (Naggar, 2009). They can irreversibly inhibit acetylcholinesterase (AChE) which is essential for the function of the central nervous system (Hu, 2010), resulting in the buildup of the neurotransmitter acetylcholine which interferes with muscular responses and in vital organs produce serious symptoms and eventually death (Mulchandani Ashok, 2001). Inhibition of AChE by any xenobiotic compound is used as a tool for assessment of toxicity of some pesticides such as organophosphates and carbamates (ML Hannam, 2008). As the pesticide residue is a potentially serious hazard to human health, the control and detection of pesticide residue plays a very important role in minimizing risk. Many methods have been developed in the last few years for the detection of organophosphorous pesticides. The most widely used methods are gas chromatography (GC), high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), immune assay and fluorescence (Hu, 2010). However, these techniques, which are time consuming, expensive and require highly trained personnel, are available only in sophisticated laboratories (Mulchandani Priti, 1999). Biosensors based on the inhibition of acetylcholine esterase (AChE) have been widely used for the detection of OP compounds. (Deo, 2005). Electro analytical sensors and biosensors provide an exciting and achievable opportunity to perform biomedical, environmental, food and industrial analysis away from a centralized laboratory due to their advantages such as high selectivity and specificity, rapid response, low cost of fabrication, possibility of miniaturization and easy to integrate in automatic devices (Buerk, 1993). Electrochemical biosensors for measurement of these pesticides are based on the inhibition of AChE and the inhibition degree is proportional to the pesticide concentration. (Arvinte Adina, 2006). In this paper, we report another method for the determination of Oganophosphorus and carbamates pesticides based on acetylcholinesterase inhibition using AC1.W2.R1/ACCHE sensors with the help of Biosensor Toxicity Analyzer (BTA). Compared with other kinds of electrochemical AChE biosensors, this method is simple, fast and more sensitive for pesticide determination with much lower detection limit.

PRINCIPLE OF BTA The target for many insecticides is an enzyme called acetylcholinesterase (AChE) (José L, 2008). Acetylcholinesterase’s (AChE) biological role is the termination of impulse transmissions at cholinergic synapses within the nervous system of the insects and mammals by rapid hydrolysis of the neurotransmitter acetylcholine. Pesticides block the catalytic activity of the active center, thus acting as inhibitors of AChE. This results in the accumulation of acetylcholine in the synaptic membrane, which blocks the nerves to process the signals properly (Mulchandani Ashok, 2011).

Fig. 1: Biosensor Toxicity Analyzer With Microflow Unit Exploration of Residual Hazardous Compounds on Cotton Fibers 563

Biosensor toxicity analyzer (BTA) works on the above mentioned principle and monitors the activity of the inhibition of AChE with the help of sensors which are equipped with an enzymatic membrane of AChE enzyme which is immobilized. It consists of two major parts, one of which is the Microflow unit and the other is Bioanalyzer. The microflow unit has the capillary arrangement which allows precise and constant flow of the liquid onto the active surface of the AChE sensor for a high level of repeatability and sensitivity in the measurements. The module has an integrated chamber in which the sensor can easily be placed or replaced (Fig 1).

EXPERIMENTAL Materials Two samples of Egyptian cotton variety namely Giza 86 (G86) were collected from the cultivation season 2009/2010. This variety is one of the most long staple Egyptian cotton exports. One of them was the classical conventional cotton and the other was organic cotton without utilizing the synthetic pesticides.

Reagents and Apparatus HPLC grades Hexane and dichloromethane solvents were used for the extraction procedure. Anhydrous and granular sodium sulfate was used as dehydrating agent throughout the extraction process. Glass wool was used as supporting material in soxhlet extraction after cleaned with acetone. A round flask (250ml) with soxhlet and condenser glassware was used to conduct the soxhlet extraction. MOPSO sodium salt was used for the preparation of buffer solution in BTA, where as Acetylthiocholine chloride (ATCCl) as enzyme substrate and Neostigmine methyl sulfate as enzyme inhibitor. AC1.W2.R1/ACCHE Sensors were used for the monitoring of AChE inhibition. Gas Chromatograph in an analytical system was equipped with a temperature programming capability, splitless injector, and capillary column MS-VF-5. It is equipped with an automatic sample injector. The operating condition of the gas chromatograph analytical system were adjusted as mentioned: Helium carrier gas with a flow rate of 1.0 ml/min, injector temperature 280 0C, column temperature 280 0C, started at 80 0C and increased for the first 08 min with the rate 10 0C/ min and after this initial phase with the rate 4 0C/ min, holding time 10 min and FID detector temperature 120 0C. All the above experiments were done at the Technical University of Liberec, University of Pardubice and Bvt technologies, Czech Republic.

Sample Preparation The determination of pesticides in samples at low concentrations is always a challenge. The main aim of any extraction process is the isolation of analytes of interest from the selected sample by using an appropriate extracting phase. The development of an appropriate sample preparation procedure involving extraction, enrichment, and cleanup steps becomes mandatory to obtain a final extract concentrated on target analytes (Turiel Esther, 2008). It is always necessary to carry out some pretreatments to get a homogeneous and representative subsample. Even if the sample is apparently homogeneous, that is, an aqueous sample, it will be at least necessary to perform a filtration step to remove suspended particles, which could affect the final determination of target analytes. However, solid samples need to be more extensively pretreated to get a homogeneous subsample (José L, 2008).

Cryogenic Homogenization It is necessary for the determination of the residual pesticides in cotton samples to turn the sample into finely chopped or ground powder. This grinding procedure should be done carefully to avoid heat generation (El-Nagar, 2004). 564 World Cotton Research Conference on Technologies for Prosperity

(a) (b) (c) Fig. 2(a): Raw Cotton (b) Freezer Mill (c) Homogenized Sample Both samples of classical conventional cotton and organic cotton are arranged around the inside of a pre-chilled Teflon mill in the form of pallets which contains a concentric Teflon ring and Teflon puck in liquid nitrogen surrounding. Each sample is milled for approximately 10 minutes with an interval of 2 min for grinding and 1 min for cooling. After the milling the resulting powder is sampled. The raw cotton samples which had been transferred to a clean Teflon bag and sealed were held overnight in liquid nitrogen vapor. Only 2 - 3 gm of the raw cotton would fit into the mill at a time and grind successfully. After each successful homogenization, the resulting powder was pooled in another clean Teflon bag. Fig 2 shows the different steps for the cryogenic homogenization. Once the entire sample was homogenized and blended, the powder was sampled, cleaned and stored for analysis.

Soxhlet Extraction (SOX) Soxhlet Extraction method was used for the extraction from both of the samples. Two different solvents hexane and dichloromethane were used for each of the sample. A total of 0.5 gm homogenized sample was transferred to the soxhlet thimble in between two layers of dehydrated sodium sulfate over a glass wool layeer. The thimble was placed in the extraction apparatus charged with 230 ml of both the solvents, separately. Samples were extracted for overnight. The extract then concentrated by turbo evaporator and stored for further analysis. At the end of the extraction process we have four extracts i.e. classical conventional cotton with hexane & dichloromethane and organic cotton with hexane & dichloromethane.

RESULTS AND DISCUSSION All the above mentioned four extracts were injected in BTA and then analyzed in Gas chromatography. For the convenience we will describe the results with respect to the solvent used for the extraction process.

Hexane

Fig. 3: Classical Cotton Sample with Hexane Exploration of Residual Hazardous Compounds on Cotton Fibers 565

Both the samples of classical cotton and organic cotton were tested on BTA. After putting the sensor in the slot and starting the pump, the buffer solution is added in the microflow unit. After some stabilization the sample is added and then the inhibitor, neostigmine methyl sulfate, is added in the solution to compare the inhibition of the sample with the standard inhibitor. The resultant graphs of the whole activity are shown in Fig 3 and Fig 4 for classical cotton and organic cotton, respectively.

Fig. 4: Organic Cotton Sample with Hexane It can be seen in the above graphs that there is response on the addition of the samples. We measure this response (∆I) and also the relative inhibition (Ri), which is calculated to quantify inhibiting effect of an inhibitor to the enzyme. Inhibiting effect is proportional to the slope of current time dependence after inhibitor or sample addition. The calculated values are shown in Table 1.

Dichloromethane The same procedure as mentioned in the case of the solvent hexane is repeated for the second solvent i.e. dichloromethane and the resultant graphs are shown in Fig. 5 and Fig. 6. It is quite visible in these graphs that there is a clear response on the addition of both the samples which can be compared with the slope of the standard inhibitor.

Fig. 5: Classical Cotton Sample with Dichloromethane 566 World Cotton Research Conference on Technologies for Prosperity

Fig. 6: Organic Cotton Sample with Dichloromethane Following is the description of response and relative inhibition for both the samples. It can be seen that although both classical and organic cotton samples show the change in the intensity of the current but the organic cotton sample shows more response and more inhibition with each solvent.

TABLE 1: RESPONSE AND RELATIVE INHIBITION FOR CLASSICAL AND ORGANIC COTTON Solvents Classical conventional cotton Organic cotton Response [∆I(nA)] Relative Inhibition [Ri] Response [∆I(nA)] Relative Inhibition [Ri] Hexane 1.416 -0.0002855 6.527 -0.0000745 Dichloromethane 3.208 -0.0004602 3.524 -0.0003441 Following are the chromatogram of both the samples with hexane and dichloromethane obtained by gas chromatography. Fig 7 shows the comparison of classical (red) and organic cotton sample (green) with the solvent hexane and Fig 8 shows the comparison of classical (red) and organic cotton sample (green) with the solvent dichloromethane.

Fig. 7: Comparison of Classical and Organic Sample with Hexane

Fig. 8: Comparison of Classical and Organic Sample with Dichloromethane Exploration of Residual Hazardous Compounds on Cotton Fibers 567

Although there are chemical compounds and pesticides detected such as 4,4- DDT, 4,4-DDE but organophosphorous and carbamates pesticides and their derivatives are not detected in all the four extracts.

CONCLUSION This study demonstrates a method based on AChE inhibition. Contrary to other sophisticated methods, this is an easier, faster and cheaper method. It is a method that offers to different investigators an easy way to detect the presence of organophosphorous pesticide. Further research must be needed to verify the usefulness of the method presented here for the screening of pesticides on some more varieties of cotton of different regions.

ACKNOWLEDGMENT The Authors would like to thank Dr. Jan Krejci, CEO of Bvt Technologies, for his support. This work was supported under Student Grant Scheme (SGS) by Technical University of Liberec, Czech Republic.

REFERENCES [1] Alder, L. (2006). RESIDUE ANALYSIS OF 500 HIGH PRIORITY PESTICIDES: BETTER BY GC – MS OR LC – MS/MS? Wiley InterScience , 25, 838 – 865. [2] ARVINTE, A. (2006). DEVELOPMENT OF A PESTICIDES BIOSENSOR USING CARBON-BASED ELECTRODE SYSTEMS. In L.S. Chirila, & L.S. Chirila (Ed.), Chemicals as Intentional and Accidental Global Environmental Threats (pp. 337–343). Springer. [3] Blackburn, R.S. (2009). LIFE CYCLE AND ENVIRONMENTAL IMPACT. In L. GROSE (Ed.), Sustainable Cotton Production. Cambridge : Woodhead Publishing Limited. [4] Buerk, D.G. (1993). Biosensors: Theory and Applications. USA: Technomic Publishing Company,Inc. [5] Deo, R.P. (2005). Determination of organophosphate pesticides at a carbon nanotube/organophosphorus hydrolase electrochemical biosensor. Analytica Chimica Acta , 530, 185–189. [6] El-Nagar, K. (2004). Extraction of Residual Chlorinated Pesticides from Cotton Matrix. Journal of Textile and Apparel, Technology and Management , 04 (02). [7] Hu, H. (2010). A novel chemiluminescence assay of organophosphorous pesticide quinalphos residue in vegetable with luminol detection. Chemistry Central Journal. [8] José L. Tadeo. (2008). Pesticides : Classi ﬁcation and Properties. In J.L. Tadeo (Ed.), Analysis of Pesticides in Food and Environmental Samples. USA: CRC Press. [9] ML, H. (2008 ). Characterisation of esterases as potential biomarkers of pesticide exposure in the lugworm Arenicola marina (Annelida: Polychaeta). Environmental Pollution , 152, 342–350. [10] Muccio, A.D. (2006). Determination of Organophosphorus Pesticide Residues in Vegetable Oils by Single-Step Multicartridge Extraction and Cleanup and by Gas Chromatography With Flame Photometric Detector. In A.G. José L. Martínez Vidal (Ed.), Pesticide Protocols. New Jersey , USA: Humana Press Inc. [11] Mulchandani, A. (2001). Biosensors for direct determination of organophosphate pesticides. Biosensors & Bioelectronics , 16, 225–230. [12] Mulchandani, A. (2011). Microbial Biosensors for Organophosphate Pesticides. Applied Biochemistry and Biotechnology . [13] Mulchandani, P. (1999). Biosensor for direct determination of organophosphate nerve agents. 1. Potentiometric enzyme electrode. Biosensors & Bioelectronics , 14, 77–85. [14] MYERS, D. (1999). ORGANIC COTTON. In D. MYERS (Ed.), ORGANIC COTTON. LONDON: Intermediate Technology Publications Limited. [15] Naggar, A. E.-R. (2009). Clinical findings and cholineste rase levels in children of organ ophosphate s and carbamates poisoning. Eur J Pediatr , 168, 951–956. [16] Philip J. Wakelyn, N.R. (Ed.). (2007). Handbook of Fiber Chemistry. CRC Press Taylor & Francis Group. [17] S. Gordon, Y.-L. (Ed.). (2007). Cotton: Science and Technology. Cambridge: WoodHead Publishing Ltd. [18] Turiel, E. (2008). Sample Handling of Pesticides in Food and Environmental Samples. In J.L. Tadeo (Ed.), Analysis of Pesticides in Food and Environmental Samples. USA: CRC Press. 91

Studies on Composition of Oil and Fatty Acid in Bt and Non Bt Cotton (G. hirsutum)

Harijan Nagappa1 and Khadi B.M.2 1Asst. Professor (GPB), ARS, Hanumanamatti, UAS, Dharwad 2Dean (PG Studies), UAS, Dharwad

Abstract—Cotton has pride place among cash crops from earliest times. Cotton though mainly grown for fibre is also ranked as major oilseed crop in the international market. Cotton seed oil can be used for edible purpose after refining. Cotton seed oil is premium quality oil and it has no cholesterol and is vegetable oil. On an average, oil content of Bt hybrids (17.43%) were on par with non Bt hybrids (17.4 %) The Bt hybrids viz., JKCH-2245, K-5038, RCH-2, NCEN-3R, JK-Ishwar and JKCH-266 showed numerically superior over non Bt hybrids. On an average, unsaturated fatty acid of Bt and non Bt hybrids was on par with each other. The Bt hybrids viz., JKCH-2245, K-5038, RCH-2, JKCH-22, NCEN-3R and RCH-138 recorded more than 4 per cent of unsaturated fatty acid higher than non Bt hybrids, while JK-Ishwar, JKCH-1050, JKCH-66 and K-5316 non Bt hybrids had unsaturated fatty acid more than 4 per cent higher than their respective Bt versions. The myristic acid in Bt hybrids was numerically superior over non Bt hybrids which helps to increase the keeping quality of oil. The mean of 35 Bt hybrids had monounsaturated oil on par with mean of respective non Bt hybrids. JKCH-2245 Bt, K-5038, RCH-2, JKCK-22, NCEN-3R and RCH-138 were significantly superior over non Bt hybrids. Considering polyunsaturated fatty acids, JKCH-2245 and JK-Ishwar Bt hybrids were numerically superior over non-Bt hybrids. From current investigations it can be concluded that there is no significant difference in oil percentage and fatty acid composition in Bt cotton hybrids when compared to their non Bt versions.

INTRODUCTION Cotton though mainly grown for fibre is also ranked as major oil seed crop in the international market. Out of the four major products i.e., meal, hull, oil and lint, oil is the most important. Besides commercial importance in the leather industry it is also used as a lubricant. Cotton seed oil can also be used for edible purpose after refining. Cotton seed oil is premium quality as it has no cholesterol, transfree and highly stable with low flavor reversion vegetable oil. The cotton seed oil has neutral flavor, strong shelf life, low fryer turnover and extremely versatile. It is a good source of essential fatty acids (70% unsaturated, 26% saturated) and good source of vitamin E. Cotton seed oil has a fatty acid profile that makes acceptable as healthful oil and very useful as cooking and frying oil (Boghara etal, 1985). Evaluation of different Bt and non Bt cotton genotypes for seed oil and both acid profile has been carried out and presented in the paper.

MATERIAL AND METHODS A gas chromatograph, model GC – 2010 (Shimadzu, Kyoto, Japan) was used to separate methyl esters. The fatty acid methyl ester was identified by a comparison of retention time to standard methyl ester fatty acid mixtures (Sigma, Aldrich). Concentration of each fatty acid was recorded by normalization of peak areas as per cent of particular fatty acid. Phenotyping for fatty acid composition was done using Near Infrared Spectroscopy (NIRS). Eight fatty acids viz., Palmitic acid (16:0), Stearic acid (18:0), Oleic acid (18:1), Linoleic acid (18:2), Arachidic acid (20:0), Cyclopropanid (1:1), Behenic acid (22:0), and Myristic acid (14:0) were studied in 35 Bt and non Bt counterpart cotton hybrids.

Studies on Composition of Oil and Fatty Acid in Bt and Non Bt Cotton (G. hirsutum) 569

RESULTS AND DISCUSSION Cotton seed oil is the most unsaturated oil, among others include safflower, corn, soybean, rapeseed and sunflower seed oil. Cotton seed oil has a 2:1 ratio of poly unsaturated to saturated fatty acids and generally consists of 70 per cent unsaturated fatty acid including 18 per cent mono unsaturated (oleic) and 52 per cent poly unsaturated (linoleic) and 26 per cent saturated (palmatic and stearic ) oils. The fatty acid composition of cotton seed oil is determined by fatty acids viz., palmatic, oleic and linoleic acid. The myristic and stearic acid contribute to minor constituent in oil but play major role in keeping quality of oil and linoleic acid is very important in view of the health of heart. Comparison between Bt and non Bt cotton hybrids for fatty acid related traits has been presented in Table. On an average oil content of Bt was (17.43%) and non Bt was (17.40%). The results revealed that Bt gene did not affect the seed oil content. The range of saturated fatty acid varied from 31.89 (K-5038) to 40.98 per cent (K-5316) in Bt hybrids while in non Bt hybrids it ranged from 33.96 (SBCH-302) to 39.72 per cent (Ankur.651). On an average Bt hybrids (36.25%) showed slightly less content of saturated fatty acids than non Bt hybrids (36.90%). Most of the Bt hybrid showed lesser saturated fatty acid than non Bt hybrids except SBCH- 302, JK-Ishwar, JKCH-1050, SBCH-311, KDCHH-9810, JKCH-266, K-5316 and JKCH-99 cotton hybrids. The mean of unsaturated fatty acid of Bt hybrids (59.71%), was on par with non Bt hybrids (59.15%). The unsaturated fatty acid of Bt hybrids ranged between 56.30 (K-5316) and 63.40 per cent (K-5038), while non Bt hybrids varied from 56.70 (VICH-111) to 63.21 per cent (SBCH-302). The highest unsaturated fatty acids observed in K-5038 (63.40%) followed by RCH-2 (62.37%) and SBCH- 302 (62.12%) in Bt cotton hybrids. The non Bt hybrid SBCH-302 (63.21%) showed highest unsaturated fatty acids followed by JKCH-1050 (62.36%) RCH-144 and RCH-118 (61.00%). On an average around, 13.23 per cent more myristic acid was noticed in Bt hybrids (1.42%) than their non Bt hybrids (1.28%). However some of the Bt hybrids viz., K-5038, RCH-2, JKCH-1947, RCH- 134, Ankur-651, NCEN-3R, PCH-2171, PCH-2270, RCH-138 and RCH-377 showed 20 per cent higher myristic acid than their corresponding non Bt hybrids. Conversely non BT hybrids, JKCH-266(29.17%), JK-Ishwer (21.85%) and K-5316(21.80%) had more than 20 per cent higher myristic acid than their Bt versions. Brein and Wakelyn (2005) also observed one per cent myristic acid in seed cotton oil. The mean stearic acid content of Bt and non Bt hybrids was 3.88 and 3.98 per cent, respectively. The range of stearic acid varied from 3.15(K-5038Bt) to 4.49 per cent (JK-Ishwar Bt) in Bt hybrids, while in non Bt hybrids, the range was 3.33 (JKCH-266, JKCH-1050) to 4.48 per cent (Ankur-651). The non-Bt hybrids viz., PCH-2171, NCEN-3R, JKCH-1947, RCH-2, KDCHH-441 and K-5038 exhibited more stearic acid content than their counter part Bt hybrids. However, Pelin GUNC ERGONUL, Bulent ERGONUL, (2008) reported 2.89 per cent of stearic acid in cotton seed oil, Brien (2004) and Berrien and Wokelyn (2005) observed 3 per cent of stearic acid in cotton seed oil. The range of palmatic acid content was found between 28.74 (K-5038Bt) and 36.46 per cent (K- 5316Bt) per cent. The overall mean of Bt hybrids (32.37 %) and non Bt hybrids (32.92 %) did not differ much. Sharma et al (2009) observed 19.10 to 29.10 per cent range of palmatic acid Pelin GUNC ERGONUL, Bulent ERGONUL (2008) reported 23.03 per cent of palmatic acid in cotton seed oil. Mean of oleic acid (18:1) content in Bt cotton hybrids was 12.99 per cent, while in non Bt hybrids it was 12.22 per cent. The oleic acid ranged from 10.11 (K-5316) to 16.03 per cent (K-5038) in Bt hybrids while in non Bt hybrids, it ranged from 10.45 (VICH-5) to15.76 per cent (SBCH-302). Most of Bt versions showed statistically as well as numerically superior over non Bt versions for oleic acid except SBCH-302,JK-Ishwar, RCH-144, JKCH-1050, PCH-2270, NCEN-2R, RCH-118, JKCH-266, K-5316, Jk-Durga and JK-Gowri. 570 World Cotton Research Conference on Technologies for Prosperity

TABLE 1: OIL CONTENT AND FATTY ACID COMPOSITION IN BT AND NON-BT COTTON HYBRIDS

Genotypes Oil Content (%) Bt NBt % over Bt NBt % over Myristic (14:0) (%) Palmitic (16:0) (%) Stearic (18:0) (%) Bt NBt % Differ- Saturated Saturated NBt Unsaurated Unsaurated NBt Bt NBt % Bt NBt % Bt NBt % ence Fatty fatty Fatty Fatty Differ- Differ- Differ- acid Acid Acid Acid ence ence ence JKCH-2245 19.20 18.15 5.79 34.76 36.26 -4.14 61.90 59.18 4.60 1.69 1.41 19.86 31.30 32.55 -3.84 3.46 3.71 -6.74 SBCH-302 17.85 18.90 -5.56 35.15 33.96 3.50 62.12 63.21 -1.72 1.41 1.66 -15.06 31.51 30.60 2.97 3.64 3.36 8.33 K-5038 19.25 16.65 15.62 31.89 38.03 -16.1563.40 60.03 5.61 1.74 1.20 45.00 28.74 33.95 -15.35 3.15 4.08 -22.79 KDCHH-441 18.25 17.10 6.73 34.35 37.09 -7.39 61.64 60.13 2.51 1.47 1.46 0.68 30.93 33.03 -6.36 3.42 4.06 -15.76 JK-Indtra 18.85 18.65 1.07 34.21 36.33 -5.84 61.59 59.66 3.23 1.76 1.54 14.29 30.53 32.54 -6.18 3.68 3.79 -2.90 RCH-2 17.75 17.10 3.80 33.46 39.19 -14.6262.37 59.13 5.48 1.73 1.14 51.75 29.97 34.81 -13.90 3.49 4.38 -20.32 JK-Ishwar 18.00 17.15 4.96 39.53 36.93 7.04 57.60 60.35 -4.56 1.18 1.51 -21.8535.04 32.91 6.47 4.49 4.02 11.69 JKCH-1947 15.80 17.10 -7.60 35.82 38.28 -6.43 61.24 58.79 4.17 1.66 1.15 44.35 32.12 33.97 -5.45 3.70 4.31 -14.15 RCH-134 16.95 18.05 -6.09 37.52 37.92 -1.05 60.32 59.24 1.82 1.59 1.27 25.20 33.51 33.77 -0.77 4.01 4.15 -3.37 JKCH-22 16.85 19.15 -12.01 36.88 38.44 -4.06 60.95 58.31 4.53 1.60 1.09 46.79 32.85 34.23 -4.03 4.03 4.21 -4.28 Ankur-651 17.95 17.85 0.56 37.56 39.72 -5.44 60.10 58.26 3.16 1.34 0.97 38.14 33.45 35.24 -5.08 4.11 4.48 -8.26 RCH-144 17.55 14.40 21.88 35.65 35.78 -0.36 60.32 61.00 -1.11 1.43 1.58 -9.49 31.86 32.03 -0.53 3.79 3.75 1.07 JKCH-1050 17.00 17.45 -2.58 37.75 34.44 9.61 59.51 62.36 -4.57 1.43 1.66 -13.86 33.76 31.11 8.52 3.99 3.33 19.82 SBCH-311 17.10 16.80 1.79 39.49 38.32 3.05 58.52 58.17 0.60 1.25 1.21 3.31 35.06 34.18 2.57 4.43 4.14 7.00 PCH-2270 17.45 19.50 -10.51 37.76 38.46 -1.82 59.14 60.15 -1.68 1.36 1.15 18.26 33.71 34.22 -1.49 4.05 4.24 -4.48 NCEN-3R 16.75 16.40 2.13 35.88 39.31 -8.73 61.53 58.40 5.36 1.69 1.05 60.95 32.11 34.91 -8.02 3.77 4.40 -14.32 KDCHH-9810 18.25 18.60 -1.88 36.18 35.49 1.94 58.27 58.78 -0.87 1.34 1.27 5.51 32.22 31.79 1.35 3.96 3.70 7.03 NCEN-2R 17.25 17.35 -0.58 35.91 35.97 -0.17 58.92 59.53 -1.02 1.27 1.42 -10.56 32.06 32.11 -0.16 3.85 3.86 -0.26 RCH-118 18.10 18.35 -1.36 34.70 35.00 -0.86 60.93 61.00 -0.11 1.52 1.59 -4.40 31.08 31.19 -0.35 3.62 3.81 -4.99 JKCH-266 18.45 15.05 22.59 38.39 34.42 11.53 57.62 60.30 -4.44 1.02 1.44 -29.1734.36 31.09 10.52 4.03 3.33 21.02 Dhruva 17.95 17.00 5.59 37.45 37.51 -0.16 57.45 57.91 -0.79 1.13 1.14 -0.88 33.09 33.39 -0.90 4.36 4.12 5.83 K-5316 18.05 18.05 0.00 40.98 34.69 18.13 56.30 59.15 -4.82 1.04 1.33 -21.80 36.46 30.57 19.27 4.52 4.12 9.71 KDCHH-9632 17.10 16.60 3.01 35.17 37.64 -6.56 59.96 57.83 3.68 1.32 1.16 13.79 31.42 33.50 -6.21 3.75 4.14 -9.42 JK-Varun 13.75 17.55 -21.65 36.60 36.85 -0.68 58.57 58.75 -0.31 1.18 1.11 6.31 32.68 32.99 -0.94 3.92 3.86 1.55 PCH-2171 17.55 17.65 -0.57 34.66 37.91 -8.57 60.70 58.91 3.04 1.62 1.14 42.11 31.23 34.05 -8.28 3.43 3.86 -11.14 RCH-20 17.25 16.35 5.50 36.21 37.37 -3.10 59.82 58.92 1.53 1.57 1.25 25.60 32.15 33.20 -3.16 4.06 4.17 -2.64 JK-Durga 15.20 15.60 -2.56 37.03 37.67 -1.70 57.94 57.88 0.10 1.13 1.15 -1.74 33.04 33.47 -1.28 3.99 4.20 -5.00 JKCH-99 17.90 17.85 0.28 35.33 34.97 1.03 58.61 59.49 -1.48 1.39 1.33 4.51 31.59 31.26 1.06 3.74 3.71 0.81 RCH-138 17.45 18.15 -3.86 35.21 36.55 -3.67 60.90 58.47 4.16 1.64 1.10 49.09 31.42 32.71 -3.94 3.79 3.84 -1.30 JKCH-1945 16.10 16.70 -3.59 34.52 34.60 -0.23 59.85 59.17 1.15 1.72 1.43 20.28 31.09 30.95 0.45 3.43 3.65 -6.03 JK-Gowri 17.05 17.80 -4.21 37.17 37.33 -0.43 57.83 58.18 -0.60 1.32 1.32 0.00 33.16 33.30 -0.42 4.01 4.03 -0.50 RCH-377 17.85 16.55 7.85 36.91 38.00 -2.87 59.07 57.81 2.18 1.33 1.10 20.91 32.91 33.91 -2.95 4.00 4.09 -2.20 VICH-111 17.40 17.60 -1.14 36.49 37.23 -1.99 58.12 56.70 2.50 1.27 1.14 11.40 32.52 33.20 -2.05 3.97 4.03 -1.49 VICH-5 16.80 17.50 -4.00 35.82 36.08 -0.72 58.54 57.41 1.97 1.23 1.10 11.82 31.76 31.85 -0.28 4.06 4.23 -4.02 VICH-9 18.00 18.30 -1.64 36.28 37.64 -3.61 58.17 57.85 0.55 1.21 1.08 12.04 32.24 33.63 -4.13 4.04 4.01 0.75 Mean 17.43 17.40 0.51 36.25 36.90 -1.59 59.71 59.15 0.95 1.42 1.28 13.23 32.37 32.92 -1.51 3.88 3.98 -2.05 Std. Dev. 1.06 1.68 1.54 0.21 1.41 0.30 TABLE 2

Genotypes Oleic (18:1) (%) Linoleic (18:2) (%) Arachidic (20:0) (%) Behanic (22:0) (%) CPA (1:1) (%) Bt NBt % Differ- Bt NBt % Differ- Bt NBt % Differ- Bt NBt % Differ- Bt NBt % Differ- ence ence ence ence ence JKCH-2245 14.86 12.43 19.55 47.04 46.75 0.62 0.92 0.99 -7.07 1.02 1.11 -8.11 1.08 1.14 -5.26 SBCH-302 14.58 15.76 -7.49 47.54 47.45 0.19 0.91 0.87 4.60 1.12 0.98 14.29 1.11 1.07 3.74 K-5038 16.03 12.70 26.22 47.37 47.33 0.08 0.87 1.01 -13.86 1.10 1.14 -3.51 1.03 1.15 -10.43 KDCHH-441 14.55 13.38 8.74 47.09 46.75 0.73 0.90 1.01 -10.89 1.04 1.09 -4.59 1.05 1.13 -7.08 JK-Indtra 14.75 12.85 14.79 46.84 46.81 0.06 0.95 0.99 -4.04 1.02 1.01 0.99 1.04 1.11 -6.31 RCH-2 15.14 11.94 26.80 47.23 47.19 0.08 0.92 1.05 -12.38 1.00 1.05 -4.76 1.04 1.17 -11.11 JK-Ishwar 11.31 13.45 -15.91 46.29 46.90 -1.30 1.08 0.99 9.09 1.09 1.02 6.86 1.17 1.14 2.63 JKCH-1947 14.82 11.57 28.09 46.42 47.22 -1.69 0.96 1.06 -9.43 1.06 1.12 -5.36 1.11 1.15 -3.48 RCH-134 13.73 12.64 8.62 46.59 46.60 -0.02 1.05 1.00 5.00 1.17 1.05 11.43 1.23 1.16 6.03 JKCH-22 14.29 11.35 25.90 46.66 46.96 -0.64 1.03 1.01 1.98 1.27 1.12 13.39 1.22 1.17 4.27 Ankur-651 13.05 10.79 20.95 47.05 47.47 -0.88 0.96 1.01 -4.95 1.07 1.16 -7.76 1.16 1.18 -1.69 RCH-144 13.32 14.32 -6.98 47.00 46.68 0.69 0.96 0.94 2.13 1.09 1.07 1.87 1.05 1.13 -7.08 JKCH-1050 13.19 13.78 -4.28 46.32 48.58 -4.65 0.99 0.94 5.32 1.12 1.00 12.00 1.17 0.99 18.18 SBCH-311 12.44 11.73 6.05 46.08 46.44 -0.78 1.05 0.99 6.06 1.22 1.16 5.17 1.22 1.16 5.17 PCH-2270 12.28 12.73 -3.53 46.86 47.42 -1.18 1.03 0.99 4.04 1.14 1.15 -0.87 1.18 1.14 3.51 NCEN-3R 14.10 11.04 27.72 47.43 47.36 0.15 0.98 1.01 -2.97 1.14 1.18 -3.39 1.07 1.17 -8.55 KDCHH-9810 12.07 12.06 0.08 46.20 46.72 -1.11 1.00 0.93 7.53 1.11 1.04 6.73 1.15 1.12 2.68 NCEN-2R 12.28 12.89 -4.73 46.64 46.64 0.00 0.97 1.00 -3.00 1.13 1.15 -1.74 1.16 1.17 -0.85 RCH-118 13.40 14.34 -6.56 47.53 46.66 1.86 0.93 1.03 -9.71 1.05 1.30 -19.23 1.09 1.19 -8.40 JKCH-266 10.75 13.02 -17.43 46.87 47.28 -0.87 0.97 0.91 6.59 1.14 1.01 12.87 1.16 1.04 11.54 Dhruva 11.01 11.07 -0.54 46.44 46.84 -0.85 1.07 1.06 0.94 1.28 1.22 4.92 1.22 1.21 0.83 K-5316 10.11 12.26 -17.54 46.19 46.89 -1.49 1.11 1.05 5.71 1.23 1.21 1.65 1.20 1.21 -0.83 KDCHH-9632 12.64 11.07 14.18 47.32 46.76 1.20 0.93 1.08 -13.89 1.07 1.16 -7.76 1.12 1.19 -5.88 JK-Varun 12.02 11.11 8.19 46.55 47.64 -2.29 0.98 1.00 -2.00 1.12 1.12 0.00 1.17 1.14 2.63 PCH-2171 13.88 12.02 15.47 46.82 46.89 -0.15 0.96 0.95 1.05 1.08 1.04 3.85 1.10 1.12 -1.79 RCH-20 13.59 12.58 8.03 46.23 46.34 -0.24 1.05 0.98 7.14 1.35 1.13 19.47 1.26 1.17 7.69 JK-Durga 11.35 12.06 -5.89 46.59 45.82 1.68 1.07 1.06 0.94 1.19 1.26 -5.56 1.21 1.23 -1.63 JKCH-99 12.26 12.41 -1.21 46.35 47.08 -1.55 0.97 0.95 2.11 1.10 1.10 0.00 1.19 1.12 6.25 RCH-138 14.40 11.38 26.54 46.50 47.09 -1.25 1.00 0.99 1.01 1.34 1.13 18.58 1.21 1.13 7.08 JKCH-1945 13.29 12.29 8.14 46.56 46.88 -0.68 0.97 0.99 -2.02 1.08 1.13 -4.42 1.14 1.14 0.00 JK-Gowri 11.91 12.02 -0.92 45.92 46.16 -0.52 1.05 1.07 -1.87 1.14 1.13 0.88 1.22 1.22 0.00 RCH-377 12.75 10.91 16.87 46.32 46.90 -1.24 0.97 1.01 -3.96 1.12 1.12 0.00 1.13 1.15 -1.74 VICH-111 11.33 10.59 6.99 46.79 46.11 1.47 1.05 1.07 -1.87 1.13 1.16 -2.59 1.17 1.22 -4.10 VICH-5 11.67 10.45 11.67 46.87 46.96 -0.19 1.02 1.05 -2.86 1.12 1.18 -5.08 1.18 1.20 -1.67 VICH-9 11.59 10.87 6.62 46.58 46.98 -0.85 0.97 1.02 -4.90 1.18 1.14 3.51 1.19 1.19 0.00 Mean 12.99 12.22 6.95 46.72 46.93 -0.45 0.99 1.00 -1.16 1.13 1.12 1.54 1.15 1.15 -0.16 Std. Dev. 1.36 0.47 0.05 0.07 0.05

Studies on Composition of Oil and Fatty Acid in Bt and Non Bt Cotton (G. hirsutum) 571

On an average, linoleic acid (18:2) in Bt and non Bt hybrid was 46.72 and 46.93 per cent, respectively. It ranged from 46.11 (VCH-111) to 48.58 per cent (JKCH-1050) in non Bt hybrids while Bt hybrids varied from 46.08 (SBCH-311) to 47.54 per cent (SBCH-302). However, Pelin GUNC ERGONUL, Bulent ERGONUL, (2008) reported 56.01 per cent of linoleic acid and Brein and Wakelyn (2005) and Brien (2004)observed 52 per cent in cotton seed oil. On an average arachidic acid content of Bt and non Bt hybrids was 0.99 and 1 per cent respectively. The mean behanic acid (22:0) in Bt hybrids was 1.13 per cent and non Bt hybrids was 1.12 per cent. Similarly cycloproponide acid content of Bt hybrids was 1.15 per cent and non Bt hybrids was 1.15 per cent. So, the content of arachidic acid, behanic acid and cycloproponide acid did not much get influenced by Bt gene. As many as 20 Bt hybrids had more than 60 per cent of unsaturated fatty acids. The hybrids viz., K- 5038(63.4%), SBCH-302 (63.2%) and JKCH-1050 (62.36%) non Bt, hybrids showed statistically higher unsaturated fatty acids than RCH-2 Bt cotton hybrid (62.37%).

CONCLUSION From the current investigations it can be concluded that there was no significant changes seen for oil percentage and fatty acid composition in the Bt hybrids when compared to their non Bt versions. It also appears that the presence of the Bt gene does not affect the oil content and its profile.

REFERENCES [1] Brien, R.D., 2004, Fats and Oils: Formulating and Processing for Applications, pp. 1–567. [2] Brein, R.D. and Walkelyn, P.J., 2005, Cotton seed oil: An oil for transfer options. Inform. Nov. 2005, 16(11): 667–679. [3] Boghara, D.G., Mehta, N.P. and Pethani, K.V., 1985, “Genetic studies on oil content in upland cotton gossypium hirsutum L.”, Gujrat Agric. Univ. Res. J., 10(2). 1–4. [4] Pelin GUNC ERGONUL, Bulent ERGONUL, 2008. Changes in fatty acid profiles and omega fatty acid contents of selected vegetable oil during refining process. Electronic Journal of Environmental, Agricultural and Food Chemistry, 7 (13), 2008. [2655–2660]. [5] Sharma, D.H., Dharminder Pathaki, A.K., Atwal and Sangha, M.K., 2009, Genetic variation for some chemical and biochemical characteristics in cotton seed oil, Cotton Res. Dev., 23(1): 1–7. 92

The Properties of the Naturally-Pigmented Cotton Cultivated in Nakornsawan Field Crop Research Center Thailand

Piyanut Jingjit1 and Parinya Seebunruang2 1Faculty of Engineering, Rajamangala University of Technology Thanyaburi, Thailand 2Nakornsawan Field Crop Research Center, Thailand E-mail: [email protected]

Abstract—Two types of naturally pigmented cotton fibers studied in this research were green cotton and brown cotton. Both fibers were grown, picked, and ginned in the Nakornsawan Field Crop Research Center, Thailand. When these cotton fibers were observed under optical microscope, the green fibers showed green colour substances scattered throughout the tissue of the fibers and the brown fibers showed brown color substances concentrated mainly in the center of the fibers. The fiber colour of the green and brown fibers were not uniform, some fiber are apparently darker than others. Due to the fineness, length and strength of the green fibers, the fibers were able to be spun, with OE spinning machine, into fine yarn (no. 24). For the brown fibers, the fibers were found to be coarser, shorter and weaker and they were only suitable for spun into medium or coarse yarn. The percentage of fiber loss during spinning process were high, the green fiber 32% and the brown fiber 41.4%, these were partly because of their short fiber index which were higher than standard. The obtained yarns were used to produce knitted fabrics on a circular knitting machine using single jersey construction. The color of the obtained fabrics was found to be uniform all through the fabrics. The fabrics were tested for light fastness, and the light fastness level of the fabric produced from the green fibers was 3-4 and for the fabric produced from brown fiber was 6-7.

INTRODUCTION The naturally pigmented cotton fibers in this study were selected from limited hues of naturally coloured cotton cultivated in Thailand. The naturally coloured cotton had been developed and cropped scatteringly in some areas mostly in the northern and north-eastern regions of the country, in which they still obscure conserved and maintained theirs provincial handicraft and souvenir markets. These pigmented cottons had long been struggled to survive, partly as theirs short staple which made them harder to spin and weave with high speed advanced technology machineries than new developed long stapled white cottons. Therefore, the naturally coloured cottons cultivated in the country were almost entirely for hand-spun yarns and traditional woven fabrics as shown in figure 1 and 2. Despite the fact that there were advantages of the naturally coloured cotton, they never overcome the major advantage of the dyed cotton as its boundless colour varieties.

Fig. 1: Yarn Spinning by Hand Fig. 2: Weaving Fabric by Traditional Shutter Loom

The Properties of the Naturally-Pigmented Cotton Cultivated in Nakornsawan Field Crop Research Center Thailand 573

The fibers selected for this research were naturally coloured cotton in shades of brown and green, cultivated in 2010 in the Nakornsawan Field Crop Research Center. The fibers were harvested by hand and separated the fibers from the seeds by small cotton gin at the research center. The fibers then kept in opaque packaging, as the light might effects shade of the fibers, during transporting to spinning factory where they would be tested with HVI Spectrum fiber testing instrument. After the fibers had been tested, they were respectively produced into yarns with open-end spinning machine and then knitted into fabrics with circular knitting machine as shown in figure 3 and 4.

Fig. 3: Brown Cotton Spinning by OE Machine Fig. 4: Fabric Knitted by Circular Knitting Machine Considering the test results - the fineness, length and strength, the naturally green cotton fiber was able to be spun into relatively finer yarn (no. 24) than the brown cotton, which was coarser, shorter and weaker than the green cotton, so the brown cotton was only applicable for producing medium or coarser yarns which in this trial the number 20. The yarns were knitted into a green cotton fabric and a brown cotton fabric with basic single jersey construction. The knitted fabrics were check for the fabric counts and weights. The average fabric count for the brown fabric were 44.4 course per inch and 29.4 wale per inch with average fabric weight of 184.64 gram/m2 and the green fabric were 42.6 course per inch and 31.8 wale per inch with weight of 151.82 gram/m2.

THE FIBER PROPERTIES

Microscopic Examination The fibers were observed and examined under optical microscope for their general and distinctive appearances - as shown in figure 5. The green fibers showed green colour substances scattered unevenly but thoroughly the tissue of the fibers. One the other hand, the brown fibers showed brown colour substances concentrated mainly only in the inner center of the fibers. The both fibers showed marked distinct colour from the ordinary white cotton. However, the colours of the green and brown fibers were not consistent - some fibers were apparently darker than others and the colour hues and shades were different in each fiber. Under the same magnification, it appeared that the brown fibers were coarser and rounder with higher degree of cell wall thickness than the green ones.

574 World Cotton Research Conference on Technologies for Prosperity

a) The Green Cotton Fiber b) The Brown Cotton Fiber Fig. 5: Photomicrograph Showing the Cross-Sectional and Longitudinal Views of the Naturally Coloured Cottons

Manufacturing Quality Parameters The fibers were measured influential quality parameters for yarn and fabric manufacturing processes and trades with HVI Spectrum fiber testing instrument. Spinning Consistency Indeex (SCI) The average spinning consistency index of the green fiber was 146 - indicating that the fiber had favourable spinning potential. On the contrary, the brown fiber had only 42 which considered as very low average spinning consistency index. Therefore, the overall fiber spinnability of the green fiber was greater than the brown one. Micronaire The average micronaire of the green fiber was 2.23 - meaning that the fiber was very fine which either because of very small perimeter and mature or medium perimeter and immature. On the other hand, the brown fiber had 6.00 which considered as very coarse fiber because of its large in perimeter with different degrees of maturity. Hence, the green fiber and the brown fiber were in the opposite ends of the micronaire range. Maturity Index The maturity index indicates the degree of cell wall thickness within a cotton sample. The maturity index ranges from below 0.07 (uncommon) to above 0.95 (very mature). The green cotton had average maturity index at 0.80 which indicated slightly immature and the brown cotton had average maturity index at 0.93 which indicated mature state. Upper Half Mean Length (UHML) Fiber length affects yarn strength, yarn evenness, and the efficiency of the spinning process. The fineness of the yarn which can be successfully produced from given fibers is also influenced by the length of the fiber. The general commercial length range for cotton was between below 0.99 inch (short) to above 1.26 inch (extra long). The upper half mean length of the green cotton was 1.127 inch which was within the range of long fiber. In the contrary the length of the brown cotton was 0.868 inch which was within the range of short fiber. The Properties of the Naturally-Pigmented Cotton Cultivated in Nakornsawan Field Crop Research Center Thailand 575

Uniformity Index The uniformity index means the distribution of length of fibers in the test sample expressing in percentage. The degree of uniformity index of the green fiber was 82.9 implying that the fiber was within the range of medium. In the contrary, the brown cotton was in the range of very low with index at 76.1. Therefore, the green cotton was likely to produce higher quality yarn than the yarn produced from the brown cotton. Short Fiber Index The short fiber index indicates the amount of fibers (by weight) that are less than 0.5 inch in length, expressing in percentage. The short fiber index of the tested fibers should not exceed 8.0% but both of them - the green cotton and the brown cotton - were 9.8% and 13.6% respectively, denoted that the quality of the both fibers were likely to be depreciated and to have high percentage of fiber lose during yarn production, which conformed to the calculation of the percentage of fiber loss during the actual spinning processes - the green fiber 32% and the brown fiber 41.4. Strength The fiber strength, expresses as breaking tenacity, considered to be one of the most crucial factor in determining potential strength of yarn, reports in grams-force per tex, and range from 33 and above (very strong) to 20 and below (very weak). The strengths of the green and brown cottons were 30.7 gram/tex (strong) and 24.1 gram/tex (weak), respectively. Elongation The elongation of the fiber is the distance of the fiber extended before break, expressing in percentage. The percentage of fiber elongation ranges from 5 and below (very low) to 7.6 and above (very high). The average percentage of fiber elongations of the green and brown cottons were 7.6% (very high) and 7.1% (high) respectively.

Moisture There is no commercial moisture regain assessment value for raw cotton required in general cotton fiber trade, as the wax layer intact to the fiber barricades liquid water to enter the fiber make it difficult to achieve standard moisture content value of 8.5% which, otherwise, easier to achieve by processed cotton fibers. The values of moisture in the test sample of the raw green and brown cottons were 5.8% and 5.9% respectively. Trash Count, Trash Area, and Trash Grade The contamination in the raw cotton fiber is all waste and its removal aggravates cost. The green cotton had average trash count of 52, trash area of 0.77%, and trash grade 6, while the brown cotton had average of trash count of 38, trash area of 0.45%, and trash grade 4.

THE FABRIC PROPERTIES

Microscopic Examination The greige fabrics knitted from the green and brown cotton fibers were observed under stereo microscope for their general and distinctive appearances - as shown in figure 6. Considered with similar fabric construction, the greige green and brown fabrics showed distinctive colours from the ordinary greige white cotton fabric. 576 World Cotton Research Conference on Technologies for Prosperity

a) b) c)

Fig. 6: Photomicrograph Showing Greige Cotton Fabrics a) White Cotton b) Naturally Green Colour Cotton, and c) Naturally Brown Colour Cotton

Colour Fastness to Light The greige fabrics were tested to determine the resistance of the colour to the action of an artificial light source representative of natural daylight (D65), standard test method ISO 105-B02: Colour fastness to artificial light: Xenon arc fading lamp test. The light fastness level of the fabric produced from the green fibers was 3-4 and for the fabric produced from brown fiber was 6-7, indicated that the green fabric fade much quicker than the brown fabric when exposed to light.

CONCLUSION The two types of naturally pigmented cotton fibers studied in this research had distinctive appearance, characteristic, and properties form the common white cotton fibers and also different from each other. The green colour cotton fiber was likely to be produced into the better quality yarn than the brown colour cotton fiber considering the spinning consistency index, fineness, length, strength, and elongation. However, the most disadvantage of the green cotton fiber was its light fastness which was slightly inadequate for textile products to be exposed to sunlight and possibly fading quickly if it was hung dry outdoor. Therefore, the application for the green fiber was limited. On the other hand, the yarn production parameters of the brown fiber seems to be deficient but its magnificent light fastness properties made it be applicable to wider range of products than the green one.

ACKNOWLEDGEMENT This work was supported by the Thailand Textile Institute, and any attempt at any level cannot be satisfactorily completed without the contribution and collaboration of the Nakornsawan Field Crop Research Center, KongKiat Textile Co., Ltd., and Thanuluk Public Company Ltd.

REFERENCES [1] Morton, W.E. and Hearle, J.W.S. (2008) Physical properties of Textile Fibres. Fourth edition, Cambridge, the Textile Institute. [2] Myer, Dorothy. And Stolton, Sue. (1999) Organic Cotton: From Field to Final Product. London, Intermediate Technology Publications Ltd. [3] Saville, B.P. (1999) Physical Testing of Textiles. Cambridge, the Textile Institute. [4] Fan, Qinguo. (2005) Chemical Testing of Textiles. Cambridge, the Textile Institute. [5] Smith, C. Wayne. And Cothren, J. Tom. (1999) Cotton: Origin, History, Technology, and Production. John Wiley & Son Inc. [6] Lewin, Menachem. And Pearce, Eli M. (1998) Handbook of Fiber Chemistry. New York, Marcel Dekker Inc. [7] Wakelyn, P.J. and Gordon, M.B. (1995) Cotton, naturally, Textile Horizons, Volume 15, no 1, pp 36-38.