Indian Journal of Fibre & Textile Research

VOLUME 26 NUMBER 4 DECEMBER 2001

CONTENTS Influence of some process parameters on the properties of polyester jet-spun yarns 349 G K Tyagi & Dhirendra Sharma

Assessment of tensile properties of cotton yarns 354 Abhijit Majumdar

Objective measurement of structural parameters of rotor-spun yarns 358 Arindam Basu

A comparative study of MTS and equivalent MJS yarns 366 K R Salhotra, S M Ishtiaque & Akshay Kumar

Prediction of micro-spun yarn lea CSP using artificial neural networks 372 N Shanmugam, S K Chattopadhyay , M V Vivekanandan & H V Sreenivasamurthy

Influence of fibre finish on characteristics of polyester jet-spun yarns in relation to total draft and spinning speed 378 S Dhamija, G K Tyagi , R Munshi & K R Salhotra Core coverage in DREF-III friction-spun yarns 387 R Chattopadhyay , K R Salhotra, S Dhamija & R C D Kaushik

Influence of spin finish and opening roller speed on the mechanical properties of polyester OE rotor yarns produced with different draw-off nozzles 392 G K Tyagi , Rakesh Jindal & K R Salhotra Relationship between tensile properties of fibres and nonwoven fabrics 398 P C Patel & V K Kothari Opto-electronic measurement of spinning tension 403 B K BEHERA, S SUBRAMANIAN & ASHISH GARG Effect of specimen size and strain rate on the tensile properties of heat-sealed and needle-punched nonwoven fabrics 409 P C Patel & V K Kothari

Physico-mechanical properties of fabrics prepared from blends of sulphonated jute fibre with natural and synthetic fibres 414 Mohammed Ali, A Jabber Mian, M Nurul Islam, Md Rabiul Awual, Syed Fazal- E-Karim & A M Sarwaruddin Chowdhury

A novel technique of cotton dyeing with reactive dyes at neutral pH 418 S D Bhattacharya & B J Agarwal

Improving the dyeability of natural colorants on cotton by cationization 425 Seong-il Eom, Dong-yoon Shin & Kee-jong Yoon

Physico-chemical study of dyed wool: Part — Bougainvillaea as wool colourant with mixed mordant 432 J P Mathur & C S Bhandari Conference Report

Fifty-seventh All India Textile Conference 438

Book Review

Textile testing: Fibre, yarn and fabric 441 by A Basu; reviewed by A R Garde

Annual Index 443 Indian Journal of Fibre & Textile Research Vol. 26, December 2001, pp. 349-353

Influence of some process parameters on the properties of polyester jet-spun yarns

G K Tyagi and Dhirendra Sharma The influence of fibre denier, ribbon width, main draft and yarn linear density on the properties of polyester jet-spun yarns has been studied by using factorial design. It is observed that the ribbon width has a direct effect on the tensile properties of MJS yarns, depending on the fibre and yarn linear densities. The use of higher main draft substantially improves the tensile properties but adversely affects the evenness, rigidity and hairiness.

Keywords : Air-jet spinning, Flexural rigidity, Main draft, Polyester yarn, Ribbon width

Indian Journal of Fibre & Textile Research Vol 26, December 2001, pp. 354-357

Assessment of tensile properties of cotton yarns

Abhijit Majumdar The influence of rate of extension on the tensile properties of cotton yarns has been studied. The relationship between different tensile parameters of cotton yarns obtained from Uster Tensorapid-3 and Uster Tensojet has been developed. It is observed that the results obtained from these two tensile testers show very good correlation. The average strength-time coefficient and breaking extension-time coefficient of cotton yarns of varying count have also been derived using the formula proposed by Meredith. The absolute value of both the time coefficients decreases with the increase in yarn fineness beyond 50s.

Keywords: Breaking extension, Cotton, Tenacity, Uster Tensorapid-3, Uster Tensojet, Work of rupture

Indian Journal of Fibre & Textile Research Vol. 26, December 2001, pp. 358-365

Objective measurement of structural parameters of rotor-spun yarns

Arindam Basu An intensive study has been carried out to define the structure of rotor-spun yarns objectively and to find out the contribution of structural parameters to yarn properties. It is observed that the measured twist of rotor-spun yarn is correlated poorly with yarn tenacity, count strength product (CSP) and elongation-at-break. The structural parameters of the yarn are highly correlated with yarn tenacity, extension, CSP and hairiness. The addition of twist enhances the correlation in some cases. Keywords: Cotton, Count strength product, Elongation-at-break, Hairiness, Ring-spun yarn, Rotor-spun yarn, Wrapper fibre, Yarn tenacity Indian Journal of Fibre & Textile Research Vol. 26, December 2001, pp. 366-371

A comparative study of MTS and equivalent MJS yarns

K R Salhotra, S M Ishtiaque and Akshay Kumar

Murata twin-spun (MTS) yarns have been compared with equivalent Murata jet-spun (MJS) yarns at different ply twist levels both in S and Z directions. It is observed that the doubling increases the tenacity, breaking extension and flexural rigidity of both the yarns. MTS yarns are stronger and less rigid than the equivalent MJS yarns. The percentage increase in tenacity, breaking extension, and flexural rigidity is more in MTS doubled yarns. The subjective assessment of fabric handle shows that MTS yarn fabrics are softer than MJS yarn fabrics before and after finishing treatment. Finished fabrics are softer than grey and bleached fabrics for both types of yarns. Keywords: Air-jet spinning, Fabric handle, Murata jet-spun yarn, Murata twin-spun yarn, Plying, Polyester/viscose yarn

Prediction of micro-spun yarn lea CSP using artificial neural networks

N Shanmugam, S K Chattopadhyay , M V Vivekanandan and H V Sreenivasamurthy A back-propagation artificial neural network has been used to develop a model relating to cotton fibre properties and micro- spun yarn lea CSP. Fibre properties such as span length, bundle strength, fineness, breaking elongation, uniformity ratio and percentage of mature fibres have been studied. It is observed that a neural network architecture having five hidden neurons in one hidden layer and an epoch size of 12 gives better prediction. The predictions are more accurate than those obtained from regression models. The mean absolute error of neural network model is found to be 60% lower than those of the regression models. Keywords: Artificial neural network, Back-propagation neural network, Fibre quality index, Lea CSP, Microspinning

Influence of fibre finish on characteristics of polyester jet-spun yarns in relation to total draft and spinning speed

S Dhamija, G K Tyagi, R Munshi and K R Salhotra

The influence of level of fibre finish in relation to total draft and spinning speed on characteristics of polyester MJS yarns has been studied. It is observed that different levels of fibre finish exhibit different trends at different drafts. A higher level of fibre finish significantly increases the tensile properties but adversely affects the flexural rigidity. Both yarn hairiness and abrasion resistance show an initial improvement followed by deterioration with the increase in fibre finish. Within the spinning speed of 150- 210 m/min, the yarn evenness characteristics generally deteriorate with the increase in spinning speed, whereas the yarn tensile properties improve. The flexural rigidity shows a minimum at a spinning speed of 150 m/min. The influence of total draft on tenacity, breaking extension, abrasion resistance, flexural rigidity and hairiness is similar to that of spinning speed.

Keywords : Air-jet spinning, Fibre finish, Polyester yarn, Spinning speed Indian Journal of Fibre & Textile Research Vol. 26, December 2001, pp. 387-391

Core coverage in DREF-III friction-spun yarns

R Chattopadhyay, K R Salhotra, S Dhamija and R C D Kaushik The appearance of DREF-III friction-spun core yarns has been studied subjectively in respect of the coverage of core by the sheath fibres. It is observed that the core coverage increases with the increase in sheath component, irrespective of the form of core. However, it is not possible to hide the core completely even with a very high sheath content of 85%.

Keywords : Core coverage, Core-spun yarn, DREF-III spun yarn, Friction spinning, Polyester/viscose yarn

Influence of spin finish and opening roller speed on the mechanical properties of polyester OE rotor yarns produced with different draw-off nozzles

G K Tyagi, Rakesh Jindal and K R Salhotra The effect of spin finish level, opening roller speed and types of draw-off nozzle on the mechanical properties of the polyester OE rotor yarns has been studied. It is observed that the higher level of spin finish and notched nozzle offer considerable advantage in rotor spinning in respect of yarn tensile properties. The opening roller speed has the greatest influence on yarn breaking strength, breaking extension, work of rupture and abrasion resistance. All these properties deteriorate to different degree, depending upon the level of spin finish. Twist efficiency is higher with a higher level of spin finish, higher opening roller speed and a notched nozzle.

Keywords: Draw-off nozzle, Fibre friction, Opening roller speed, Polyester yarn, Spin finish, Twist efficiency

Relationship between tensile properties of fibres and nonwoven fabrics

P C Patel and V K Kothari The stress-strain behaviour of spunbonded needle-punched fabric, spunbonded heat-sealed fabric and staple fibre needle- punched fabric has been studied using wide-width tensile test method. The stress-strain behaviour of constituent fibres of these fabrics has also been studied and the structural parameters of nonwoven fabrics evaluated as these are the main two factors which influence the mechanical properties of nonwoven fabrics. The fibre network theory has been used to predict the stress-strain behaviour of fabric using the fibre data and structural parameters of nonwoven fabrics. It is observed that there is good agreement between theoretical and experimental values in case of heat-sealed spunbonded nonwoven fabric. In case of needle-punched fabrics, the stress-strain curve of the staple fibre fabric shows major deviation from the experimental curve while the stress-strain curves for spunbonded needle-punched fabrics show substantial deviation from the experimental curves. The slippage of fibres is a dominating factor in the deformation of needle-punched nonwoven fabrics in general and staple fibre fabrics in particular and hence both the modulus and breaking stress are found to be much lower than the theoretical values. The structure of nonwoven fabrics is the most important factor affecting the tensile behaviour of these fabrics.

Keywords: Heat-sealed fabric, Needle-punched fabric, Nonwoven fabric, Stress-strain behaviour, Tensile properties

Indian Journal of Fibre & Textile Research Vol. 26, December 2001, pp. 403-408 Opto-electronic measurement of spinning tension

B K Behera, S Subramanian and Ashish Garg A non-contact measurement of spinning tension based on opto-electronic principle has been discussed. The relationship between spinning tension and various yarn properties has also been studied to examine the authenticity of the proposed opto- electronic method. The results show that the value of spinning tension obtained by the tensometer correlates well with that obtained by the opto-electronic method. The proposed method is quick, reliable and more practical. Keywords: Cotton, Image processing, Opto-electronic principle, Polyester/viscose yarn, Spinning tension

Effect of specimen size and strain rate on the tensile properties of heat-sealed and needle-punched nonwoven fabrics

P C Patel and V K Kothari The tensile behaviour of heat-sealed and needle-punched spunbonded nonwoven fabrics has been evaluated by conventional narrow-strip and wide-width test methods using a wide range of strain rates. The tensile properties of these fabrics are influenced by the specimen size and strain rate, depending on the fabric structure. The initial modulus obtained from narrow-strip test is found to be significantly lower as compared to that obtained from wide-width test of needle-punched nonwoven fabrics, while the specimen width has very little effect on the initial modulus in case of heat-sealed nonwoven fabrics. The breaking stress of narrow-strip samples is always lower than that of the wide-width samples, irrespective of structure type. The effect of strain rate on breaking extension is marginal in case of needle-punched fabrics but significant in case of heat-sealed fabrics. The fabric structure influences the tensile behaviour of both heat-sealed and needle-punched nonwoven fabrics in general and at slow strain rates in particular.

Keywords: Heat-sealed nonwoven fabric, Needle-punched nonwoven fabric, Strain rate, Tensile properties

Physico-mechanical properties of fabrics prepared from blends of sulphonated jute fibre with natural and synthetic fibres

Mohammed Ali, A Jabber Mian, M Nurul Islam, Md Rabiul Awual, Syed Fazal-E-Karim and A M Sarwaruddin Chowdhury The plain woven fabrics have been prepared from the blends of sulphonated jute fibre with natural and synthetic fibres, and their geometrical, physico-mechanical and drapping properties studied. It is observed that the blended fibre fabrics show improved textile properties, almost similar to those of the cotton fabrics.

Keywords: Drape coefficient, Jute fibre, Sulphonation, Tensile strength

A novel technique of cotton dyeing with reactive dyes at neutral pH

S D Bhattacharya and B J Agarwal Cotton fabric was treated with optimum concentrations of polyacrylamide and epichlorohydrin, dried, cured and then studied for morphological changes occurred due to the treatment. The modified fabric was then dyed with selected commercial reactive dyes under neutral pH in the absence of electrolyte by different dyeing sequences. The dyeability and fastness properties of the modified and dyed samples were assessed and then compared with those of the conventionally dyed sample. It was observed that the simultaneous polyacrylamide-epichlorohydrin treatment and dyeing enhances the dyeability of cotton at neutral pH with a series of commercial reactive dyes. The probable mechanism for dye fixation on polymer treated fabric has been proposed.

Keywords : Cotton, Dyeing, Epichlorohydrin, Polyacrylamide, Reactive dye

Improving the dyeability of natural colorants on cotton by cationization

Seong-il Eom, Dong-yoon Shin and Kee-jong Yoon Cotton fabric was cationized with several cationizing reagents before dyeing with natural colorants (Redwood, Gromwell, Cochineal, Goldthread and Amur cork tree) for improving its dyeability. The K/S value of cationized cotton fabric dyed with Redwood and Cochineal was higher than that of untreated one. In case of Gromwell, though the K/S value of the cationized fabric was higher than that of untreated one, the fabric showed poor levelness. Cationization of cotton had no effect on the dyeability of Goldthread and Amur cork tree. It is observed that when the concentration of NaOH exceeds beyond a certain level, NaOH hydrolyzes the cationizing agent and the K/S values of dyed materials decrease. The optimum concentrations of NaOH in cationization have been determined for dyeings with different natural colorants.

Keywords: Cationization, Cotton, Dyeing, Natural colorants

Physico-chemical study of dyed wool: Part IBougainvillaea as wool colourant with mixed mordant

J P Mathur and C S Bhandari The extract of red petaloid bracts of bougainvillaea has been used as wool colourant with mixed mordants and the physico- chemical properties of the dyed samples studied. The petaloid bracts when treated with water at 97.5°C for nearly 20 min yield 7.43% of bougainvillaea (BV) colourant. The optimum conditions for dyeing of wool have been determined as pH 4.5, BV concentration 0.06 g per gram of wool, temperature 97.5°C, and time 45 min. It is observed that the use of lanthanum (III) as first mordant and chromium (VI) as second mordant reduces the quantity of Cr (VI) in the spent dye bath and causes less damage to the wool fibre in comparison to the dyed yarn mordanted with Cr (VI) alone. This binary mixed-mordant dyeing also reduces the environmental pollution caused due to the discharge of toxic chromium ion in the effluent.

Keywords: Bougainvillaea petaloid, Dyeing, Wool