ABSTRACT MANDAL, SONALI. Colorant

ABSTRACT

MANDAL, SONALI. Colorant Database for Cationized Cotton. (Under the direction of Dr. Peter J. Hauser.)

The use of cationized cotton is currently one of the sustainable methods of dyeing cotton with anionic dyes like fiber-reactive and direct dyes. It enables the dyeing of cotton without the use of salt and with higher dye exhaustion. During the dyeing phase of wet processing, the effluent load is reduced considerably with good fastness properties. However, even with all these benefits the use of cationized cotton lacks acceptance in the industry. The most commonly used cationization agent is 3-chloro-2- hydroxypropyltrimethylammonium chloride (CHPTAC). Several studies reported appearance of change in hue in samples dyed with cationized cotton. This problem potentially restricts the use of current primary databases in predicting dye recipes when using cationized cotton. Hence it is necessary to develop new primaries for cationized cotton.

In this study, a colorant database was developed for 23 reactive dyes of various classes and manufacturing companies. These dyes were selected on the basis of their current use in industry as primary colorants for developing shades. Two treatment levels of CHPTAC were applied on cotton and samples were dyed at various % shades. It was observed that cationized cotton primaries gave better match to the standard than conventional primaries on cationized cotton.

by Sonali Mandal

A thesis submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirement for the degree of Master of Science

Textile Chemistry

Raleigh, North Carolina

2013

APPROVED BY:

Dr. David Hinks Dr. George Hodge

Dr. Peter J. Hauser Chair of Advisory Committee

DEDICATION

This work is dedicated to my father, my mother, my brother, my family and my friends.

BIOGRAPHY

Sonali Mandal, daughter of Uttam Kumar Mandal and Sulekha Mandal, was born on

September 28, 1989 in Mumbai, India. She has a younger brother Abhishek Mandal. She graduated from Fr. Agnels Multipurpose School & Junior College in 2007. She obtained her Bachelor of Technology degree in Fiber and Textile Processing Technology from the

Institute of Chemical Technology (previously known as University Department of

Chemical Technology), Mumbai in 2011. She will receive her Master of Science degree in Textile Chemistry in 2013 and will remain at North Carolina State University to pursue her Doctor of Philosophy degree in Fiber and Polymer Science.

iii

ACKNOWLEDGMENTS

I want to thank Dr. Peter J. Hauser for his patience, time and guidance during the research and writing this thesis. Also, I want to thank Dr. David Hinks and Dr. George

Hodge for their general advice and guidance. A special thanks to Mr. Jeffery Krauss, the dyeing and finishing pilot lab manager for always being available and for helping me perform the experiments in the lab. This research would not have been possible without the financial support of Cotton Incorporated. I want to thank all the staff at

Cotton Incorporated, especially Mary Ankeny. I want to also thank my family especially my parents for encouraging me to pursue my graduate studies in the USA and providing constant support throughout my education.

TABLE OF CONTENTS

LIST OF TABLES ...... vii

LIST OF FIGURES ...... x

1. Introduction ...... 1

2. Literature Review ...... 3

2.1 Cotton Fibers ...... 3

2.2 Coloration of Cotton ...... 4

2.2.1 Vat Dyes ...... 4

2.2.2 Sulfur Dyes ...... 5

2.2.3 Pigments ...... 5

2.2.4 Natural Dyes ...... 6

2.2.6 Direct Dyes ...... 6

2.2.7 Reactive Dyes ...... 7

2.3 Chemistry of Reactive Dyes ...... 7

2.4 Environment issues related to Reactive dyes ...... 13

2.5 Cationization of Cotton with CHPTAC ...... 15

2.6 Colorant primaries and color matching ...... 20

2.7 Need for new primaries ...... 27

3. Experimental ...... 28

3.1 Materials ...... 28

3.2 Equipment ...... 31

3.3 Pretreatment Procedure ...... 31

3.4 Cationization Procedure ...... 32

3.5 Dyeing Procedures ...... 32

3.6 Evaluation Procedures ...... 41

3.7 Colorant Database Evaluation ...... 42

4. Results and Discussion ...... 43

4.1 Dyed Cationized cotton samples ...... 43

4.2 Comparison of K/S values ...... 44

4.3 Comparison of L*, a* and b* values ...... 68

4.4 Repeatability in dyeing cationized cotton ...... 80

4.5 Comparison of dye bath exhaustion ...... 83

4.6 Comparison of fastness test ratings ...... 85

4.7 Color matching using conventional and cationized primaries ...... 94

5. Conclusions ...... 106

6. Recommendations for Future Work ...... 108

References ...... 109

LIST OF TABLES

Table 1: List of Chemical and Auxiliaries ...... 29

Table 2: List of Dyes ...... 30

Table 3: Concentration of Glauber’s salt and Soda Ash used in Dyeing Samples ...... 33

Table 4: Conventional Dyeing Procedure for Novacron Dyes...... 35

Table 5: Conventional Dyeing Procedure for Remazol Dyes...... 36

Table 6: Conventional Dyeing Procedure for Drimaren K Dyes...... 37

Table 7: Conventional Dyeing Procedure for Drimaren CL Dyes...... 38

Table 8: Conventional Dyeing Procedure for Drimaren X Dyes...... 39

Table 9: Dyeing Procedure for Cationized Cotton samples...... 40

Table 10: K/Ssum values for Reactive Yellow 143 ...... 45

Table 11: K/Ssum values for Reactive Yellow 206 ...... 46

Table 12: K/Ssum values for Reactive Yellow 168 ...... 47

Table 13: K/Ssum values for Reactive Red 238 ...... 48

Table 14: K/Ssum values for Reactive Red 266 ...... 49

Table 15: K/Ssum values for Reactive Blue 235 ...... 50

Table 16: K/Ssum values for Reactive Blue 268 ...... 51

Table 17: K/Ssum values for Novacron Super Black R ...... 52

Table 18: K/Ssum values for Novacron Super Black G ...... 53

Table 19: K/Ssum values for Remazol Golden Yellow RGB ...... 54

Table 20: K/Ssum values for Remazol Red RGB ...... 55

vii

Table 21: K/Ssum values for Reactive Blue 250 ...... 56

Table 22: K/Ssum values for Reactive Blue 21 ...... 57

Table 23: K/Ssum values for Reactive Yellow 125 ...... 58

Table 24: K/Ssum values for Reactive Red 147 ...... 59

Table 25: K/Ssum values for Reactive Blue 209 ...... 60

Table 26: K/Ssum values for Reactive Yellow 176 ...... 61

Table 27: K/Ssum values for Reactive Red 197 ...... 62

Table 28: K/Ssum values for Reactive Black 5 ...... 63

Table 29: K/Ssum values for Reactive Orange 70 ...... 64

Table 30: K/Ssum values for Reactive Red 243 ...... 65

Table 31: K/Ssum values for Reactive Blue 52 ...... 66

Table 32: K/Ssum values for Reactive Blue 214 ...... 67

Table 33: L*, a*, b* values of CD, C25 and C50 samples ...... 69

Table 34: Repeatability in Dyeing Cationized Cotton on 50 g/L CHPTAC fabric ...... 81

Table 35: Wash Fastness Test Results ...... 85

Table 36: Crock Fastness Test Results ...... 89

Table 37: Recipes for dyeing the standards (targets)...... 95

Table 38: Auxiliaries for Dyeing the Standards ...... 96

Table 39: Dyeing Procedure for the Standards...... 96

Table 40: Recipes for Dyeing Green Thumb Shades ...... 98

Table 41: Recipes for Dyeing Stained Wood Shades ...... 99

viii

Table 42: Recipes for Dyeing Solar Wind Shades ...... 100

Table 43: Recipes of Dyeing Heavy-Hearted Shades ...... 101

Table 44: Recipes for Dyeing Green Thumb Shades with Remazol Dyes ...... 103

Table 45: Recipes for Dyeing Stained Wood Shades with Remazol Dyes ...... 104

Table 46: Recipes of Dyeing Heavy-Hearted Shades with Remazol Dyes ...... 105

LIST OF FIGURES

Figure 1: Chemical Structure of Cotton ...... 3

Figure 2: Reactive Dye features ...... 8

Figure 3: Fiber-reactive groups in commercial reactive dyes. [7] ...... 10

Figure 4: Reactions of DCT reactive dyes ...... 12

Figure 5: Reactions of VS reactive dyes ...... 13

Figure 6: Dyeing of Cationized Cotton ...... 16

Figure 7: Synthesis of CHPTAC ...... 17

Figure 8: Reactions of CHPTAC ...... 18

Figure 9: CIELAB Color Space ...... 22

Figure 10: Plot of K/S vs dye concentration for a sample [35] ...... 26

Figure 11: Plot of K/Ssum vs. % Shade for Reactive Yellow 143 ...... 45

Figure 12: Plot of K/Ssum vs. % Shade for Reactive Yellow 206 ...... 46

Figure 13: Plot of K/Ssum vs. % Shade for Reactive Yellow 168 ...... 47

Figure 14: Plot of K/Ssum vs. % Shade for Reactive Red 238 ...... 48

Figure 15: Plot of K/Ssum vs. % Shade for Reactive Red 266 ...... 49

Figure 16: Plot of K/Ssum vs. % Shade for Reactive Blue 235 ...... 50

Figure 17: Plot of K/Ssum vs. % Shade for Reactive Blue 268 ...... 51

Figure 18: Plot of K/Ssum vs. % Shade for Novacron Super Black R ...... 52

Figure 19: Plot of K/Ssum vs. % Shade for Novacron Super Black G ...... 53

Figure 20: Plot of K/Ssum vs. % Shade for Remazol Golden Yellow RGB ...... 54

Figure 21: Plot of K/Ssum vs. % Shade for Remazol Red RGB ...... 55

Figure 22: Plot of K/Ssum vs. % Shade for Reactive Blue 250 ...... 56

Figure 23: Plot of K/Ssum vs. % Shade for Reactive Blue 21 ...... 57

Figure 24: Plot of K/Ssum vs. % Shade for Reactive Yellow 125 ...... 58

Figure 25: Plot of K/Ssum vs. % Shade for Reactive Red 147 ...... 59

Figure 26: Plot of K/Ssum vs. % Shade for Reactive Blue 209 ...... 60

Figure 27: Plot of K/Ssum vs. % Shade for Reactive Yellow 176 ...... 61

Figure 28: Plot of K/Ssum vs. % Shade for Reactive Red 197 ...... 62

Figure 29: Plot of K/Ssum vs. % Shade for Reactive Black 5 ...... 63

Figure 30: Plot of K/Ssum vs. % Shade for Reactive Orange 70 ...... 64

Figure 31: Plot of K/Ssum vs. % Shade for Reactive Red 243 ...... 65

Figure 32: Plot of K/Ssum vs. % Shade for Reactive Blue 52 ...... 66

Figure 33: Plot of K/Ssum vs. % Shade for Reactive Blue 214 ...... 67

Figure 34: Dye exhaustion for Reactive Yellow 176 ...... 83

Figure 35: Dye Exhaustion for Reactive Red 197 ...... 84

Figure 36: Dye Exhaustion for Reactive Black 5 ...... 84

1. Introduction

Clothing is regarded as one of the basic necessities for human beings and the textile industry holds a significant share in global trade in manufactured goods. A research by the Secretariat of the Seoul International Color Expo reveals that 84.7% respondents think color as an important factor while choosing products [1]. The coloration of textile goods thus acts as an important process in the textile industry.

Cotton is the most important natural fiber in the world due to its incomparable properties. The textile dyeing and finishing sector is known to consume large amounts of water and chemicals. Many efforts are being made to develop ecofriendly dyeing processes with lesser consumption of dyes and auxiliaries. The process of treating the effluent from the textile industry is an important step so as the make the effluent safe for discharging into water streams. However, these treatments are expensive and are not always viable since a typical textile effluent contains various types of dyes, metals, surfactants and other auxiliaries. Also, treating the effluent does not reduce the usage of the dyes and chemicals.

Cotton is mainly dyed with reactive dyes which require large amounts of salt to increase the dye affinity. However, the salt does not get exhausted and remains in the bath along with unexhausted and hydrolyzed dye. Also, in order to get rid of the hydrolyzed dye from the fiber, post dyeing scouring and multiple rinsing stages are required which consume significant amounts of water and energy. An alternative

solution to these problems is the use of cationized cotton. Cotton is treated with a cationic agent to attract the anionic dye molecules. The use of cationized cotton eliminates the need of salt, scouring and multiple rinsing processes. Also, with an appropriate level of treatment lesser amount of dye is needed to obtain shades comparable to conventionally dyed cotton samples.

In this present work, cotton fabric was cationized using 3-chloro-2- hydroxyproplytrimethylammonium chloride and was then dyed with fiber reactive dyes. The dye exhaustion and the final shade obtained on cationized cotton are different compared to conventional cotton dyeing which the existing primaries cannot be used for color matching on cationized cotton [2, 3]. Specifically, the work has focused on creating new colorant primaries for cationized.

2. Literature Review

2.1 Cotton Fibers

Cotton is the most abundant fiber available in nature consisting of 88-96% cellulose [4]. Cotton possesses unique properties such as softness, comfort and breathability which make it the most popular among natural fibers [5]. The factors that affect the properties of cotton are color, impurities, molecular weight, fiber length, uniformity of length etc. The leading producers of cotton in the world are

China, USA, India, Pakistan and Brazil [6].

Figure 1: Chemical Structure of Cotton

Cellulose, a polymer of glucose formed by condensation polymerization of β-D- glucopyranose joined by 1, 4-glucosidic bonds, is the basic building block for cotton as shown in Figure 1 [7]. The primary alcohol group in the cellulose is the most

reactive and participates in the cellulosic reactions. Currently, cotton constitutes about 50% of the annual textile fiber production [8].

2.2 Coloration of Cotton

2.2.1 Vat Dyes

Vat dyes are one of the oldest types of dyes used for dyeing of cotton. Indigo is the most popular vat dye used for dyeing blue denim [9]. Vat dyes are water insoluble and hence needs to be reduced chemically to their leuco water-soluble forms for application on cotton. The process of reduction of vat dyes is known as vatting in which the dye reacts with a reducing agent and a base. The most commonly used reducing agent is sodium hydrosulphite which is stable in the presence of an alkali. After the leuco form of the vat dye has been applied on the fiber it needs to reoxidized to its original form using atmospheric oxygen or mild oxidizing agents like sodium per borate or hydrogen peroxide. This class of dye possesses excellent fastness properties however they are costly and have less range of hues [2, 10].

2.2.2 Sulfur Dyes

Sulfur dyes are similar to vat dyes which are used for dyeing cotton [6]. They contain sulfur linkages in their structure however the exact molecular chemistry is still unknown [7, 11]. Currently, one of the most important sulfur dyes is C.I.

Sulphur Black 1[9]. Similar to vat dyes, sulfur dyes are also water insoluble and need to be converted into their leuco forms in presence of a reducing agent and an alkali. The combination of sodium sulphide as reducing agent along with sodium hydroxide is traditionally used for solubilizing these dyes [7]. After the dye is applied on the cotton substrate it needs to be reoxidized either by atmospheric oxygen or with mild oxidizing agents like hydrogen peroxide [12]. Sodium sulphide remains in the effluent which can undergo acidification to produce hydrogen sulphide, a harmful chemical [7]. Hence this effluent needs to be treated before releasing into water streams.

2.2.3 Pigments

Pigments possess color rending properties and are insoluble in the medium of application. Since they cannot penetrate inside the fiber, they need to be fixed on the surface of the fiber by using a polymeric adhesive binding agent [12]. The fastness of the substrates colored with pigments depends on the mechanical properties of the binder [13]. The application of pigment on cotton is laborious and also stains the printing equipment which needs to be cleaned thoroughly. The pigment-binder

system influences the properties of the cotton substrate by imparting stiffness and possesses moderate to poor fastness ratings [13].

2.2.4 Natural Dyes

Natural dyes are those colorants that have natural source of origin like plants, invertebrates, minerals etc. [14]. Indigo is possibly the oldest and the most important among all the naturally occurring dyes [15]. The process of extraction of the natural dyes from their raw materials is a tedious work. Natural dyes are expensive due to low color yields and limited source of raw materials. Most natural dyes do not have affinity for cotton and hence are bonded using a mordant which acts are a chemical bridge between the dye and fiber thus improving their fastness properties [14]. They possess poor light fastness on cotton due to its hygroscopic nature [16]. The dye undergoes photochemical oxidation in presence of moisture leading to poor light fastness [17]. Hence, the fastness of the dye depends on the binding strength of the mordant.

2.2.6 Direct Dyes

Direct or substantive dyes have very high affinity for cellulosic fibers due to their narrow and flat molecular structure [12]. The straight structure of these dyes often contains one or more azo groups that are held to cellulose by secondary bonds like hydrogen bonding. These dyes are inexpensive and easy to apply and high

exhaustion rates can be achieved by adding salt or increasing the dyeing temperature [11]. However, they do not possess good wash and light fastness properties. The wash fastness can be improved by treating with a dye fixing agent that increases the molecular weight of the dye already absorbed in the fiber.

2.2.7 Reactive Dyes

Reactive dyes are the class of dyes which are capable of forming strong and stable covalent bonds with cellulose [12]. Reactive dyes are widely chosen for dyeing cotton because of their wide range of brilliant shades, multiple methods of application and good fastness properties. However, some reactive dyes have poor light and chlorine fastness. The method of dyeing regular cotton with reactive dyes follows three steps: exhaustion, fixation and washing-off. Glauber’s salt, sodium sulfate, is used for the exhaustion of reactive dyes and the washing-off step consumes large quantities of water. Due to these reasons the application of reactive dyes exhibits significant environmentally impact.

2.3 Chemistry of Reactive Dyes

Rattee and Stephen in ICI England first developed the fiber reactive dyes in 1955 and the dyes were commercialized in 1956 [7]. The reactive dyes have structure similar to acid or direct dyes and additionally have a reactive group which reacts with ionized hydroxyl groups of cellulose in the cotton fiber.

C R

B L

Figure 2: Reactive Dye features

(C = Chromophore, S = Solubilizing group, B = Bridging group, R = Reactive group,

L = Leaving group) [18]

A typical reactive dye will contain a chromophore, solubilizing groups, a bridging group, a reactive group and leaving groups as shown in Figure 2. Each of these features influences the dyeing and the fastness properties of the dye. The chromophore is the color imparting group of the dye. The solubilizing groups make the dye molecule water soluble. The bridging group connects the chromophore to the reactive group of the dye. The reactive group contains leaving groups which are replaced during the dyeing process. The most common reactive groups can be classified into halogenic cyclic azine derivatives and sulfatoethylsufone type

reactive dyes. The different types of reactive dyes commercially available are shown in Figure 3.

Dichlorotriazine (DCT) Monochlorotriazine (MCT)

Monofluorotriazine (MFT) Trichloropryimidine (TCP)

Difluorochloropyrimidine (DFCP) Dichloroquinoxaline (DCQ)

Nicotinyltriazine (NT) Vinylsulphone (VS)

Figure 3: Fiber-reactive groups in commercial reactive dyes. [7]

The dye fixation occurs in presence of alkali in which the reactive group of the dye reacts with hydroxyl groups of the cellulose. However, the dye may undergo hydrolysis with hydroxide in water. This hydrolyzed dye is incapable of forming bonds with the cellulose and reduces the wet fastness properties if these hydrolyzed dyes are not removed fully during the washing. Multiple soaping and rinsing steps are required after the dyeing process in order to remove these hydrolyzed dyes. The reactions of dichlorotriazine and vinylsulphone types of reactive dyes are shown in

Figures 4 and 5.

Cell-OH -OH

Figure 4: Reactions of DCT reactive dyes

Cell-OH -OH

Figure 5: Reactions of VS reactive dyes

2.4 Environment issues related to Reactive dyes

The process of dyeing cotton with most reactive dyes requires large amounts of salt (electrolyte) for exhaustion as well as alkali for fixation. In order to remove the hydrolyzed dye formed during the fixation, scouring and multiple rinsing steps are required. Hence, the large volume of effluent produced typically contains high concentrations of salt and alkali which pollute the environment if not treated.

The hydroxyl groups present in the cotton ionize in contact with water thus producing negative charges [19]. Reactive dyes are anionic in nature and thus get repelled by the negative charges on the cotton fiber. Thus salt is added in the bath in

order to reduce these negative charges and increasing the affinity of the dye for the fiber. For high exhaustion of the dye, large quantities of salt are required (40-100 g/L) [20]. However, these salts remain unexhausted and are added to the effluent.

The process of removal of salt from the effluent adds to the cost of production.

Even after using high concentrations of salt, complete exhaustion of the dyestuff cannot be achieved, only 60-65% gets utilized in normal dyeing systems [21]. These unexhausted dyes remain in the bath along with the hydrolyzed dye. Processes like chemical oxidation destroy the chromophore of the dye but may ultimately produce even more toxic compounds than the original dye [22]. A process that can consume less amount of dye and has high dye exhaustion can be a solution to this problem.

In order to achieve good fastness properties, it is important to remove the hydrolyzed dye from the dyed cotton substrate. Studies show that, rinsing steps consume approximately 80% of water, 90% of energy and 70% of time required in the complete dyeing process [23]. Water is consumed for rinsing after the dyeing cycle, scouring process and final rinsing step to remove the hydrolyzed dye. Also, these stages make the entire dyeing process time consuming, thereby reducing the capacity of the dyeing and finishing plant and increasing cost.

Irrespective of these drawbacks, reactive dyes are preferred over other dyes for dyeing cotton due to overall fastness and wide range of hues. Many technologies have been suggested to overcome the environmental problems associated with reactive dyes. However, many of these lack practicality.

2.5 Cationization of Cotton with CHPTAC

The use of cationized cotton is a sustainable method of dyeing cotton. It is possible to achieve 100% dye exhaustion with less dye, energy and time than conventional dyeing application methods through the use of cationized cotton [24].

It is possible to dye cotton with the use of salt and obtain high dye exhaustion and comparable or better color fastness [19]. Cationized cotton can be obtained by reacting cotton with a cationizing agent. This treatment imparts positive charges on the cotton fiber which eliminate the anionic dye repulsive forces as illustrated in

Figure 6. Hence, it is possible to dye cationized cotton without the use of salt.

Cotton Fiber

Cationizing Agent

Dye-SO3

Dye-SO3 Dye-SO3 Dye-SO3

Figure 6: Dyeing of Cationized Cotton

3-chloro-2-hydroxyproplytrimethylammonium chloride (CHPTAC) is a cationizing agent that can be used to produce cationized cotton.

CHPTAC is formed by the reaction of epichlorohydrin and trimethylamine hydrochloride as shown in Figure 7.

Figure 7: Synthesis of CHPTAC

CHPTAC in alkaline conditions forms EPTAC which further reacts with cellulose to form ether linkages as shown in Figure 8. However, EPTAC can also undergo hydrolysis in alkaline conditions to form an unreactive diol compound.

CHPTAC EPTAC

EPTAC Cationized Cotton

EPTAC Diol

Figure 8: Reactions of CHPTAC

CHPTAC can be applied to cotton by various methods like cold pad-batch, pad steam, pad bake and exhaust; however, the cold pad-batch is the most efficient method for the cationization treatment [3, 18]. The fixation efficiency is observed to decrease with increasing liquor ratio and temperature because EPTAC hydrolysis reaction is more favorable with higher concentrations of water and higher

temperature. A higher fixation of the cationizing agent on cotton can be obtained by using additives like sodium lauryl sulfate, triethanol amine, ethylene diamine tetraacetic acid etc in the exhaust method as they tend to complex with CHPTAC thus reducing the hydrolysis reaction [25].

It has been also observed that the fixation of the cationizing reagent on mercerized cotton is nearly double that of unmercerized cotton [3]. By use of cationized cotton it is possible to obtain higher color yields with direct, acid and reactive dyes [26]. The dye molecular structure has an important role when applied on cationized cotton as it is seen that the color yield differs for different dye chemistry [27]. The use of cationized cotton is not limited to cotton dyeing.

Cationized cotton can also be printed using acid, direct and reactive dyes. The printed cationized cotton samples have higher color yield, similar or better fastness properties and shorter processing cycles compared to untreated cotton [28-32].

Since direct, acid and reactive fiber dyes have high affinity for cationized cotton it can be used for removal of the dyes from the textile effluents just by cationizing waste cotton fibers. It is almost possible to remove the dyes completely from the effluent and meet the EPA standard with lower cost compared to other waste water treatment techniques [33].

One of the drawbacks of cationic cotton treatment with CHPTAC is the reduction of whiteness index of the treated fabric compared to the untreated bleached fabric

[3]. Although CHPTAC is fairly nontoxic however, EPTAC is a carcinogen and highly

irritant with is a product of the reaction of CHPTAC with sodium hydroxide [7].

Hence, it is recommended to mix the two chemicals directly in the pad trough just before the padding process in order to minimize the risk of occupational exposure.

2.6 Colorant primaries and color matching

The relationship between supplier and customer is very important in the current textile market. However, many times there are differences in the judgment of color matching if it is solely based on a human observer [34]. Hence, it is important to measure color differences on color measuring instruments. A spectrophotometer measures the reflectance of a sample across the visible spectrum. Reflectance is the ratio of reflected light and incident light. A spectral analyzer measures the reflected light and splits into its spectral components [35]. In dyeing textile goods, dyes are mixed in different proportions to obtain a color and this is called subtractive mixing.

In subtractive mixing, red, yellow and blue are the primaries when used in different proportions to obtain a color. The tristimulus values (X, Y, and Z) are the three primaries required to produce a color [36]. The chromaticity coordinates (x, y, and z) are given by:

Equation 2.1

Equation 2.2

Equation 2.3

Since x + y + z=1, it possible to plot these chromaticity coordinates on a two dimensional plot with x and y as axes called the chromaticity diagram which consists of [35]. It is possible to calculate the value of X and Z from x, y, and Y.

If a sample is viewed under a specific light source, the amount of light reflected at each wavelength can be given by Eλ * Rλ, where Eλ is the amount of light emitted and

Rλ is the amount of light reflected at each wavelength. The reflected light can be matched using the mixture of the three primaries X, Y and Z using the formula [35]:

Eλ Rλ [λ] ≡ Eλ Rλ xˉλ [X] + Eλ Rλ yˉλ [Y] + Eλ Rλ zˉλ [Z] Equation 2.4

The total amount of energy reflected is the sum of Eλ * Rλ over the visible spectrum of λ 380 to 760 nm. Similarly, the light reflected from a sample can be given by

Σ Eλ Rλ xˉλ + Σ Eλ Rλ yˉλ + Σ Eλ Rλ zˉλ Equation 2.5

From equations 2.4 and 2.5

X = Σ Eλ Rλ xˉλ Y = Σ Eλ Rλ yˉλ Z = Σ Eλ Rλ zˉλ

Since, Eλ, R, xˉλ ,yˉλ , zˉλ are known, it is possible to calculate the tristimulus values for a particular sample.

The CIELAB color space is a three dimensional system is based on three color values

[35]:

Figure 9: CIELAB Color Space

L*: lightness or black to white contribution a*: red to green contribution b*: yellow to blue contribution

The color difference is calculated from the ΔE*ab numeric value which is calculated by the equation:

ΔE*ab = √ Equation 2.6

Where,

ΔL*, Δa* and Δb* are the difference in the L*, a* and b* values between the sample and the reference color.

Color difference can also be expressed in terms of lightness difference ΔL*, chroma difference ΔC* and hue difference ΔH*.

The CMC color difference formula is given as

ΔE CMC = √ Equation 2.7

l and c are tolerance parameters for weighting of the lightness and hue differences and for textile coloration, normally l = 2 and c = 1.

* SL = for L S ≥ 16 else SL = 0.511

SC = + 0.638

SH = SC (f T +1 – f)

f = √ and

T = 0.38 + |0.4 Cos (35°+ hab,S)|

In the hue angle domain 164°≤ hab,S ≤ 345°, the equation

T = 0.56 + |0.2 Cos (168° + hab,S)| is valid.

The subscript S refers to the sample color.

The ΔE CMC value helps to decide how close the sample matches the reference standard. The recipe prediction and color matching process has the following stages: calibration of colorants, measurement of the standard, recipe computation and recipe correction.

From the Kubelka-Munk theory the function K/S is given by the equation:

K/S = (c1K1+ c2K2+ c3K3+…..+Ks)/Ss Equation 2.8

Where, c: concentrations of colorants

K: absorption coefficients

S: scattering coefficients

Subscript s identifies substrate and subscripts 1, 2, 3…. identify the individual colorants.

Kubelka-Munk theory assumes that the colorant on a substrate reflects and scatters light and the light loss through the edges is neglected [35, 36]. It also assumes uniform distribution of dyes and pigments throughout the sample and absence of interaction between them. Hence, the K/S function leads to non-linearity at high dye concentration with low reflectance values.

To calibrate the colorants, the textile substrate is dyed at different concentrations of each individual dye and read in the spectrophotometer to obtain a reflectance at each interval of the wavelength as a function of dye concentration.

The relationship between K/S and reflectance is given by:

f (R) or K/S = (1-R∞)2/2 R∞, Equation 2.9

Where,

R∞: reflectance of light of a given wavelength by a sample of infinite thickness.

Although the relationship between reflectance and dye concentration is nonlinear, the relationship between K/S and dye concentration is near linear for most dye-fiber systems within a defined range as shown in Figure 10. The reflectance spectrum of the reference standard and the substrate can be measured using a reflectance spectrophotometer. From the K/S and the reflectance values of

the standard at each wavelength it is possible to calculate the amounts of primaries needed to obtain the particular shade. In the color matching software, a series of algorithms are executed to predict the dye recipe with the lowest ΔE CMC value. The error in color matching process can be reduced by reading the standard and the sample in the same mode with larger aperture for the spectrophotometer. However, if the sample does not match the standard close enough, a correction can be applied to the existing recipe. The correction is calculated on the basis of the color value difference between the standard and the predicted recipe [36]. The algorithm iteration then corrects the recipe depending on the deviation of the current recipe from the reference standard.

Figure 10: Plot of K/S vs dye concentration for a sample [35]

2.7 Need for new primaries

Dyed cationized cotton samples have higher amounts of dye compared to traditionally dyed samples [37]. However, changes in the (redness-greenness) a*,

(yellowness-blueness) b* and (Chroma) C* and (hue) h values between the treated and untreated samples have also been reported [38]. A study on color assessment of cationized cotton reveals that apart from lower L* values, dyed cationized cotton samples showed a different trend in C* values [39]. The C* tends to level off with increasing concentration of dye on the cotton samples. However, it was also seen that the behavior of red dye on cationized cotton was unusual and different than the rest of the dyes on cationized cotton. This will limit the application of cationized cotton in the industry due to the change in appearance of shade. Also, the recipes used for dyeing untreated cotton would not be applicable for cationized cotton.

Hence, it is necessary to develop new primaries for cationized cotton to overcome this limitation.

3. Experimental

3.1 Materials

Cotton Inc. supplied greige plain woven fabric rolls of 16kgs each which were used throughout the experiment. In all, 23 reactive dyes were used along with other chemicals and auxiliaries as listed in Tables 1 and 2.

Table 1: List of Chemical and Auxiliaries

Sr. No Name Use Supplier

1. CR-2000 (65%) CHPTAC Dow Chemicals

(Cationizing agent)

2. Sodium Hydroxide (50%) NaOH Brenntag

(Alkali)

3. Sodium sulfate Glauber’s Salt Brenntag

(Electrolyte)

4. Sodium Carbonate Soda Ash Brenntag

(Alkali)

5. Carboxymethyl cellulose (size 8) CMC Rohm & Haas

(Leveling agent)

6. Primasol NB NL Wetting Agent BASF

7. Hydrogen peroxide (35%) H2O2 (Bleaching) Brenntag

8. ApolloScour SRDS Surfactant Apollo

Chemicals

9. Acetic Acid (99.85%) Acid Brenntag

10. Citric Acid Acid Brenntag

Table 2: List of Dyes

Sr. Product Name C.I. Name Supplier

1. Novacron Yellow F-4G Reactive Yellow 143 Huntsman

2. Novacron Yellow FN-2R Reactive Yellow 206 Huntsman

3. Novacron Yellow C-R Reactive Yellow 168 Huntsman

4. Novacron Red FN-R Reactive Red 238 Huntsman

5. Novacron Red FN-3G Reactive Red 266 Huntsman

6. Novacron Blue FN-R Reactive Blue 235 Huntsman

7. Novacron Brilliant Blue FN-G Reactive Blue 268 Huntsman

8. Novacron Super Black R - Huntsman

9. Novacron Super Black G - Huntsman

10. Remazol Golden Yellow RGB - Dystar

11. Remazol Red RGB - Dystar

12. Remazol Navy RGB (150%) Reactive Blue 250 Dystar

13. Remazol Turquoise G-A Reactive Blue 21 Dystar

14. Drimaren Yellow K-2R Reactive Yellow 125 Clariant

15. Drimaren Red K-4BL Reactive Red 147 Clariant

16. Drimaren Blue K-2RL Reactive Blue 209 Clariant

17. Drimaren Yellow CL-2R Reactive Yellow 176 Clariant

18. Drimaren Red CL-5B Reactive Red 197 Clariant

Table 2 Continued

19. Drimaren Navy CL-R Reactive Black 5 Clariant

20. Drimaren Yellow X-4RN Reactive Orange 70 Clariant

21. Drimaren Red X-6BN Reactive Red 243 Clariant

22. Drimaren Blue X-3LR Reactive Blue 52 Clariant

23. Drimaren Navy X-GN Reactive Blue 214 Clariant

3.2 Equipment

The greige fabric was desized in the laboratory scale Thies jet machine. The

uncationized cotton samples were dyed by the conventional method in Ahiba

Texomat Machine. The cationized cotton samples were dyed in Ahiba Nuance

machine. The samples were measured on an X-rite Colorimeter spectrophotometer

using the Color iContol Software.

3.3 Pretreatment Procedure

Warp size identification on the greige fabric was carried out using the spot test

[40]. The warp size was identified to be polyvinyl alcohol. The fabric was desized

and scoured using 2 g/L of wetting agent and 2 g/L soda ash at 100°C for 2 hrs. The

fabric was then bleached using 6 g/L of H2O2 and 3 g/L of NaOH for 2hrs at 95°C.

After the bleaching process, the fabric was rinsed and neutralized with 0.5 g/L of

acetic acid to obtain a pH of 5-6. A material to liquor ratio of 1:20 was maintained during the entire process. The fabric was finally dried.

3.4 Cationization Procedure

Cationization of cotton was carried out using a cold pad batch procedure. Two rolls of the bleached fabric were cationized with 25 g/L and 50 g/L CHPTAC treatment. CHPTAC and NaOH were mixed in the ratio of 1: 0.6 and the fabric was padded with this liquor and batched on rollers for 24hrs. After this treatment, the fabric was rinsed and neutralized with 0.5 g/L citric acid and dried.

3.5 Dyeing Procedures

Each sample approximately weighed 20g and liquor to material ratio of 20:1 was maintained for all the dyeing procedures. The uncationized cotton samples (CD samples) were dyed by the conventional method at 0.25, 1.0 and 4.0 % depth on the weight of fiber along with the dye manufacturer recommended amount of Glauber’s salt and soda ash for all the dyes as shown in Table 3.

Table 3: Concentration of Glauber’s salt and Soda Ash used in Dyeing Samples

Novacron ( Yellow, Red, Blue) dyes

% Shade 0.25 0.5 1 2 4

Glauber’s salt (g/L) 30 40 50 60 80

Soda Ash (g/L) 8 10 12 14 18

Novacron (Black) dyes

% Shade 0.5 1 2 4 8

Glauber’s salt (g/L) 40 50 60 80 100

Soda Ash (g/L) 10 12 14 18 18

Remazol dyes

% Shade 0.25 0.5 1 2 4

Glauber’s salt (g/L) 25 30 40 50 65

Soda Ash (g/L) 5 6 8 10.4 14

Drimaren K dyes

% Shade 0.25 0.5 1 2 4

Glauber’s salt (g/L) 20 30 40 60 80

Soda Ash (g/L) 10 10 15 25 40

Table 3 Continued

Drimaren CL dyes

% Shade 0.25 0.5 1 2 4

Glauber’s salt (g/L) 40 60 65 70 80

Soda Ash (g/L) 5 10 15 18 20

Drimaren X dyes

% Shade 0.25 0.5 1 2 4

Glauber’s salt (g/L) 20 30 40 60 80

Soda Ash (g/L) 5 8 10 15 20

The cationized cotton samples of 25 g/L (C25 samples) and 50 g/L (C50 samples) were dyed at 0.25, 0.5, 1.0, 2.0 and 4.0 % shades with the recommended amount of soda ash (Table 3) and without the use of salt.

For Novacron super Black R and Novacron Super Black G 0.5, 2, 8 % shades were dyed conventionally while the cationized cotton samples were dyed at 0.5, 1, 2, 4 and 8 % shades. 1 g/L of CMC was used as a leveling agent while dyeing cationized cotton with the reactive dyes [2]. The dyeing procedures are listed in Tables 4-9.

Table 4: Conventional Dyeing Procedure for Novacron Dyes.

Step Procedure

1 Heat the dyeing bath to 60°C and add the calculated amount of salt and

water.

2 Add the fabric and run the machine for 5 minutes at 60°C.

3 Add the dye and run the machine for 5 minutes at 60°C.

4 Add soda ash and continue to run the machine for 40 minutes (45minutes

for blacks) at 60°C.

5 Cool to 50°C and discard the bath.

6 Rinse the samples with hot water at 70°C and then with cold water at

room temperature.

7 Neutralize the samples using 0.5 g/L acetic acid for 5 minutes and discard

the bath.

8 Add 1 g/L of surfactant and scour the samples for 10 minutes at 95°C.

9 Rinse the samples with cold water.

10 Extract fabric and dry.

Table 5: Conventional Dyeing Procedure for Remazol Dyes.

Step Procedure

1 Add the calculated amount of salt and water at room temperature.

2 Add the wet fabric and continue to run for 5 minutes.

3 Add the dye and run for 5 minutes.

4 Add 1/3rd the calculated amount of soda ash and run for 10 minutes.

5 Heat the bath to 60°C at 1°C/min (1.8°F/min) and continue to dye at 60°C

for 10 minutes.

6 Add the 2/3rd amount of soda ash and continue to dye at 60°C for 20

minutes.

7 Cool to 50°C and discard the bath.

8 Rinse the samples with hot water at 70°C and then with cold water at

room temperature.

9 Neutralize the samples using 0.5 g/L acetic acid for 5 minutes and discard

the bath.

10 Add 1 g/L of surfactant and scour the samples for 10 minutes at 95°C.

11 Rinse the samples with cold water.

12 Extract fabric and dry.

Table 6: Conventional Dyeing Procedure for Drimaren K Dyes.

Step Procedure

1 Add the calculated amount of salt and water at room temperature.

2 Add the wet fabric and run for 5 minutes.

3 Add the dye and run for 10 minutes.

4 Add soda ash and run for 10 minutes.

5 Heat the bath to 60°C at 1°C/min (1.8°F/min) and continue dyeing for 40

minutes at 60°C.

6 Cool to 50°C and discard the bath.

7 Rinse the samples with hot water at 70°C and then with cold water at

room temperature.

8 Neutralize the samples using 0.5 g/L acetic acid for 5 minutes and discard

the bath.

9 Add 1 g/L of surfactant and scour the samples for 10 minutes at 95°C.

10 Rinse the samples with cold water.

11 Extract fabric and dry.

Table 7: Conventional Dyeing Procedure for Drimaren CL Dyes.

Step Procedure

1 Add the calculated amount salt and water at room temperature.

2 Add wet fabric in the bath and run for 5 minutes.

3 Heat to 60°C @ 1°C/min (1.8°F/min)

4 Add the dye and run for 10 minutes at 60°C.

5 Add soda ash and continue to dye for 40 minutes at 60°C.

6 Cool to 50°C and discard the bath.

7 Rinse the samples with hot water at 70°C and then with cold water at

room temperature.

8 Neutralize the samples using 0.5 g/L acetic acid for 5 minutes and discard

the bath.

9 Add 1 g/L of surfactant and scour the samples for 10 minutes at 95°C.

10 Rinse the samples with cold water.

11 Extract fabric and dry.

Table 8: Conventional Dyeing Procedure for Drimaren X Dyes.

Step Procedure

1 Add the calculated amount salt and water at room temperature.

2 Add wet fabric in the bath and run for 5 minutes.

3 Heat to 95°C @ 1°C/min (1.8°F/min)

4 Add the dye and run for 10 minutes at 95°C.

5 Add soda ash and continue to dye for 40 minutes at 95°C.

6 Cool to 50°C and discard the bath.

7 Rinse the samples with hot water at 70°C and then with cold water at

room temperature.

8 Neutralize the samples using 0.5 g/L acetic acid for 5 minutes and discard

the bath.

9 Add 1 g/L of surfactant and scour the samples for 10 minutes at 95°C.

10 Rinse the samples with cold water.

11 Extract fabric and dry.

Table 9: Dyeing Procedure for Cationized Cotton samples.

Step Procedure

1 Add the calculated amount of water, dye, soda ash and CMC in the beaker.

2 Add the wet fabric and seal the beaker.

3 Heat the chamber to 60°C (95°C for Drimaren X dyes) at 2°C/min.

4 Continue dyeing for 40 minutes (45 minutes for Novacron black dyes) at

60°C.

5 Cool to 40°C and discard the bath.

6 Rinse the samples with hot water at 70°C and then with cold water at

room temperature.

7 Neutralize the samples using 0.5 g/L acetic acid for 5 minutes and discard

the bath.

8 Rinse the samples with cold water.

9 Extract fabric and dry.

3.6 Evaluation Procedures

K/Ssum of all the samples was measured where,

K/Ssum = sum of the K/S values over the wavelength from 360 to 750nm.

Spectrophotometer reading conditions:

- Reflectance mode

- Specular condition Included

- Port Diameter = 25 mm

- UV energy Excluded

- Average of 4 readings

- Across the visible spectrum of 360 to 750 nm at 10nm intervals

The formula used for calculating the dye bath exhaustion is:

% E = 1 – (AAD / ABD) X 100, where

AAD = sum of absorbance of the dye bath after the dyeing cycle over the wavelengths

360 to 750 nm.

ABD = sum of absorbance of the dye bath before the dyeing cycle over the wavelength

360 to 750 nm.

AATCC Test method 61-2A was followed to carry out Wash fastness tests [41].

AATCC Test method 8 was followed to carry out crocking fastness tests [41].

3.7 Colorant Database Evaluation

Reflectance spectra of CD, C25 and C50 samples dyed using different concentrations of each colorant were measured on the spectrophotometer and a new colorant database was created. To formulate a recipe, the standard and the substrate were read on the spectrophotometer and the three colorants to be used as primaries were selected. The software predicted the starting recipes using the conventional and cationized primaries which were then dyed on the cationized cotton and were compared to the standard on the basis of the ΔE CMC value. The recipe correction was applied to the samples dyed with Remazol dyes in which the samples dyed with the predicted recipe was read on the spectrophotometer and the software calculated the correction to be applied to the existing recipe.

4. Results and Discussion

4.1 Dyed Cationized cotton samples

Cationized cotton contains positive charges which attracts the anionic reactive dyes thus eliminating the use of salt. However, it is seen that dyed cationized cotton samples tend to have leveling problems. The reason for unlevel dyeing is due to the strong attraction between the cationic sites on the fiber and the anionic dye which increases the strike of the dye as soon as it comes in contact with fabric. Hence, carboxymethyl cellulose (CMC) is commonly used as a leveling agent while dyeing cationized cotton with anionic dyes. CMC is a negatively charged polymer with acts as a competitor to the anionic dye for the cationic sites thus reducing the strike of the dye [7].

The samples obtained by dyeing 25 g/L CHPTAC fabric were level for all % shades and dyes by visual inspection. However, the 0.25 and 0.5% shades for 50 g/L

CHPTAC samples were unlevel for all the dyes. 50 g/L CHPTAC samples had more cationic sites available than dye available from the 0.25 and 0.5% shades. Due to this, even 1 g/L of CMC was not effective to control the high strike of dye and thus leading to patchy dyed samples.

4.2 Comparison of K/S values

K/Ssum values for all the samples are reported in Tables 10-32 and the plots of

K/Ssum vs. % shade are reported in Figures 11-33. The K/Ssum has been reported for all the samples in order to incorporate the change in λmax due to change in hue for the dyed cationized cotton samples. It can be clearly seen from these plots and tables that the C50 samples have higher K/Ssum compared to the conventionally dyed samples. More amounts of dye are present on C50 samples than on the CD samples.

The K/Ssum values for C25 samples are slightly higher or comparable to CD samples up to 1% shades after which C25 samples have lesser K/Ssum values. C25 samples have lesser number of cationic sites hence, when more amount of dye is added in the bath there are not enough cationic sites available for the dye to get exhausted and thus C25 samples have lesser amount of dye on the fabric for % shades greater than 1%.

The C25 samples achieve an early plateau region due to lesser color yield at higher % shades compared to CD and C50 samples. The pattern of plot of K/Ssum vs.

% shade is different of each dye. For some dyes the difference in the color yield between C50 and CD samples is very high and for some dyes this difference is less.

However, the color yield for C50 samples remains higher for all the dyes compared to the CD and C25 samples. Hence, lesser amount of dye is required to achieve a similar shade on cationized cotton compared to untreated cotton.

Table 10: K/Ssum values for Reactive Yellow 143

Reactive Yellow 143

%Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 6.8 430 13.1 430 31.5 430

0.5 24.1 430 47.7 430

1 23.3 430 37.1 430 86.6 430

2 62.1 430 127.9 430

4 88.4 430 93.4 430 161.8 430

Reactive Yellow 143 180.0 160.0 140.0

120.0

100.0 CD 80.0 K/Ssum C25 60.0 C50 40.0 20.0 0.0 0 1 2 3 4 5 % Shade

Figure 11: Plot of K/Ssum vs. % Shade for Reactive Yellow 143

Table 11: K/Ssum values for Reactive Yellow 206

Reactive Yellow 206

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 28.0 435 31.2 430 42.1 430

0.5 48.7 430 77.9 430

1 86.8 435 75.9 430 137.5 430

2 109.7 430 206.7 435

4 228.6 435 151.0 430 268.0 435

Reactive Yellow 206 300.0

250.0

200.0

150.0 CD

K/Ssum C25 100.0 C50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 12: Plot of K/Ssum vs. % Shade for Reactive Yellow 206

Table 12: K/Ssum values for Reactive Yellow 168

Reactive Yellow 168

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 20.0 415 27.0 415 38.8 415

0.5 42.9 415 70.1 415

1 67.5 415 70.6 415 117.9 415

2 133.3 415 180.4 415

4 200.4 415 162.2 415 241.7 420

Reactive Yellow 168 300.0

250.0

200.0

150.0 CD

K/Ssum C25 100.0 C50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 13: Plot of K/Ssum vs. % Shade for Reactive Yellow 168

Table 13: K/Ssum values for Reactive Red 238

Reactive Red 238

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 19.3 550 21.8 550 39.4 550

0.5 35.5 550 75.7 550

1 61.8 550 56.8 550 132.8 550

2 87.7 550 183.9 550

4 183.9 550 120.4 550 251.7 525

Reactive Red 238 300.0

250.0

200.0

150.0 CD

K/Ssum C25 100.0 C50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 14: Plot of K/Ssum vs. % Shade for Reactive Red 238

Table 14: K/Ssum values for Reactive Red 266

Reactive Red 266

%Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 45.9 525 48.8 525 71.5 525

0.5 76.8 525 144.3 520

1 154.6 520 126.6 525 212.4 520

2 190 520 298.1 515

4 311.2 515 243.9 520 364.5 515

Reactive Red 266 400.0

350.0

300.0

250.0

200.0 CD

K/Ssum 150.0 C25 C50 100.0

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 15: Plot of K/Ssum vs. % Shade for Reactive Red 266

Table 15: K/Ssum values for Reactive Blue 235

Reactive Blue 235

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 28.0 625 28.3 625 43.2 625

0.5 52.2 620 75.2 625

1 90.9 625 81.4 620 141.6 625

2 129.9 620 215.3 625

4 279.3 620 192.4 620 315.8 620

Reactive Blue 235 350.0

300.0

250.0

200.0 CD 150.0 K/Ssum C25

100.0 C50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 16: Plot of K/Ssum vs. % Shade for Reactive Blue 235

Table 16: K/Ssum values for Reactive Blue 268

Reactive Blue 268

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 38.8 635 36.1 635 73.3 640

0.5 61.8 635 148.1 640

1 131.2 635 103.1 645 233.4 640

2 162.1 640 325.8 640

4 318.7 635 219.3 635 416.5 640

Reactive Blue 268 450.0 400.0 350.0

300.0

250.0 CD 200.0 K/Ssum C25 150.0 C50 100.0 50.0 0.0 0 1 2 3 4 5 % Shade

Figure 17: Plot of K/Ssum vs. % Shade for Reactive Blue 268

Table 17: K/Ssum values for Novacron Super Black R

Novacron Super Black R

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.5 90.5 590 100.3 575 184.4 605

1 176.1 570 334.7 585

2 325.1 600 266.5 575 469.8 580

4 402.0 580 626.3 565

8 654.9 565 527.8 580 735.0 560

Novacron Super Black R 800.0

700.0

600.0

500.0

400.0 CD

K/Ssum 300.0 C25 C50 200.0

100.0

0.0 0 2 4 6 8 10 % Shade

Figure 18: Plot of K/Ssum vs. % Shade for Novacron Super Black R

Table 18: K/Ssum values for Novacron Super Black G

Novacron Super Black G

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.5 94.0 605 99.8 605 198.6 605

1 157.5 605 319.8 605

2 331.6 605 261.7 605 475.7 610

4 382.7 605 631.2 610

8 677.7 605 475.6 605 715.5 610

Novacron Super Black G 800.0

700.0

600.0

500.0

400.0 CD

K/Ssum 300.0 C25 C50 200.0

100.0

0.0 0 2 4 6 8 10 % Shade

Figure 19: Plot of K/Ssum vs. % Shade for Novacron Super Black G

Table 19: K/Ssum values for Remazol Golden Yellow RGB

Remazol Golden Yellow RGB

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 15.9 430 17 430 33.6 430

0.5 32.8 430 61.3 430

1 51.6 430 44.7 430 100.1 430

2 70.1 430 166.6 430

4 171.2 425 105.3 430 230.6 425

Remazol Golden Yellow RGB 250.0

200.0

150.0 CD

K/Ssum 100.0 C 25 C 50 50.0

0.0 0 1 2 3 4 5 % Shade

Figure 20: Plot of K/Ssum vs. % Shade for Remazol Golden Yellow RGB

Table 20: K/Ssum values for Remazol Red RGB

Remazol Red RGB

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 18.3 535 21.8 535 43.0 535

0.5 31.6 535 82.9 530

1 61.9 535 51.4 535 121.6 530

2 84 535 191.7 530

4 196.3 530 133.4 535 254.4 525

Remazol Red RGB 300.0

250.0

200.0

150.0 CD

K/Ssum C 25 100.0 C 50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 21: Plot of K/Ssum vs. % Shade for Remazol Red RGB

Table 21: K/Ssum values for Reactive Blue 250

Reactive Blue 250

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 29.1 615 35.9 615 47.1 615

0.5 55.3 615 103.7 615

1 103.9 615 98.3 615 185.4 615

2 167.8 610 302.5 610

4 355.4 610 271 610 441.8 610

Reactive Blue 250 500.0 450.0 400.0 350.0

300.0 250.0 CD

K/Ssum 200.0 C 25 150.0 C 50 100.0 50.0 0.0 0 1 2 3 4 5 % Shade

Figure 22: Plot of K/Ssum vs. % Shade for Reactive Blue 250

Table 22: K/Ssum values for Reactive Blue 21

Reactive Blue 21

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 13.8 675 17.1 675 29.0 675

0.5 28.8 675 60.8 675

1 43.3 675 52.1 675 124.0 675

2 71.9 675 203.7 675

4 150.8 675 118.7 675 295.6 675

Reactive Blue 21 350.0

300.0

250.0

200.0 CD 150.0 K/Ssum C 25 100.0 C 50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 23: Plot of K/Ssum vs. % Shade for Reactive Blue 21

Table 23: K/Ssum values for Reactive Yellow 125

Reactive Yellow 125

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 24.5 420 37.9 420 41.4 425

0.5 48.7 420 85.2 425

1 85.9 420 85.2 415 143.9 425

2 144.5 420 234.8 420

4 229.9 420 196.7 415 293.4 420

Reactive Yellow 125 350.0

300.0

250.0

200.0 CD 150.0 K/Ssum C25

100.0 C 50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 24: Plot of K/Ssum vs. % Shade for Reactive Yellow 125

Table 24: K/Ssum values for Reactive Red 147

Reactive Red 147

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 17.1 550 18.9 545 32.3 550

0.5 32.5 550 66.2 550

1 58.0 550 45 545 110.3 550

2 86.4 545 185.4 550

4 192.1 550 142.8 545 245.5 550

Reactive Red 147 300.0

250.0

200.0

150.0 CD

K/Ssum C25 100.0 C 50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 25: Plot of K/Ssum vs. % Shade for Reactive Red 147

Table 25: K/Ssum values for Reactive Blue 209

Reactive Blue 209

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 21.8 630 27.7 630 35.5 630

0.5 48.3 625 64.2 630

1 78.1 630 82.5 625 139.1 630

2 133.6 625 239.9 630

4 254.4 625 229.2 625 363.0 625

Reactive Blue 209 400.0

350.0

300.0

250.0

200.0 CD

K/Ssum 150.0 C 25 C 50 100.0

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 26: Plot of K/Ssum vs. % Shade for Reactive Blue 209

Table 26: K/Ssum values for Reactive Yellow 176

Reactive Yellow 176

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 19.8 435 24.1 425 50.7 435

0.5 40.7 425 85.8 435

1 64.7 435 64.2 425 134.2 435

2 96.4 430 194.5 430

4 156.3 435 131.0 430 250.5 430

Reactive Yellow 176 300.0

250.0

200.0

150.0 CD

K/Ssum C25 100.0 C 50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 27: Plot of K/Ssum vs. % Shade for Reactive Yellow 176

Table 27: K/Ssum values for Reactive Red 197

Reactive Red 197

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 18.6 550 20.6 550 34.0 550

0.5 35.9 550 67.0 550

1 69.2 550 55.2 550 123.2 550

2 94.5 550 184.5 550

4 192.0 550 138.4 550 251.2 550

Reactive Red 197 300.0

250.0

200.0

150.0 CD

K/Ssum C 25 100.0 C 50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 28: Plot of K/Ssum vs. % Shade for Reactive Red 197

Table 28: K/Ssum values for Reactive Black 5

Reactive Black 5

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 46.1 605 45.9 605 102.1 605

0.5 87.2 605 172.6 605

1 172.1 605 144.3 605 277.0 610

2 247.1 605 405.2 605

4 482.7 610 371.1 605 542.2 580

Reactive Black 5 600.0

500.0

400.0

300.0 CD

K/Ssum C 25 200.0 C 50

100.0

0.0 0 1 2 3 4 5 % Shade

Figure 29: Plot of K/Ssum vs. % Shade for Reactive Black 5

Table 29: K/Ssum values for Reactive Orange 70

Reactive Orange 70

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 19.4 440 22.5 425 34.1 435

0.5 37.4 430 68.9 435

1 72.0 435 62.8 430 113.3 435

2 103.1 425 188.9 435

4 217.6 435 161.7 425 265.9 435

Reactive Orange 70 300.0

250.0

200.0

150.0 CD

K/Ssum C 25 100.0 C 50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 30: Plot of K/Ssum vs. % Shade for Reactive Orange 70

Table 30: K/Ssum values for Reactive Red 243

Reactive Red 243

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 18.4 555 28.9 555 42.5 555

0.5 47.8 555 80.7 555

1 64.4 555 77.2 555 133.0 555

2 121.4 555 209.0 555

4 226.9 555 179.1 555 282.2 555

Reactive Red 243 300.0

250.0

200.0

150.0 CD

K/Ssum C 25 100.0 C 50

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 31: Plot of K/Ssum vs. % Shade for Reactive Red 243

Table 31: K/Ssum values for Reactive Blue 52

Reactive Blue 52

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 16.6 630 34.3 630 43.2 630

0.5 50.2 630 80.0 630

1 65.2 630 63 630 135.4 630

2 101.7 630 229.3 630

4 236.3 630 150.3 625 342.7 630

Reactive Blue 52 400.0

350.0

300.0

250.0 CD 200.0 C 25 K/Ssum 150.0 C 50 100.0

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 32: Plot of K/Ssum vs. % Shade for Reactive Blue 52

Table 32: K/Ssum values for Reactive Blue 214

Reactive Blue 214

% Shade K/S CD λ max CD K/S C25 λ max C25 K/S C50 λ max C50

0.25 22.2 620 28.3 615 53.6 615

0.5 49 615 100.5 615

1 79.0 615 86.4 615 159.2 615

2 164.5 615 254.3 610

4 294.7 615 253 615 366.9 610

Reactive Blue 214 400.0

350.0

300.0

250.0

200.0 CD

K/Ssum 150.0 C 25 C 50 100.0

50.0

0.0 0 1 2 3 4 5 % Shade

Figure 33: Plot of K/Ssum vs. % Shade for Reactive Blue 214

4.3 Comparison of L*, a* and b* values

Table 33 compares the L*, a* and b* values for all the samples. For a particular dye and shade, the L*, a* and b* values are different for C50 and C25 samples when compared to the corresponding CD samples. For instance, considering the Reactive

Red 266 dye at 4% shade, for the CD sample L*= 38.4, a*= 54.12, b*= 26.28, for the

C25 sample L*= 42.43, a*= 57.41, b*= 27.02 and for C50 sample L*= 39.07, a*=

56.04, b*= 31.72. The C25 sample above is lighter, redder and bluer while the C50 sample is darker, greener and yellower compared to the CD sample. These differences are observed for all the shades and dyes. This restricts the use of the recipes from existing conventional primaries on cationized cotton since the shades obtained on cationized cotton will be different than that on untreated cotton. Also, it is noticed that the difference in the appearance of the hues is greater with red dyes.

Table 33: L*, a*, b* values of CD, C25 and C50 samples

Dye % Shade Sample L* a* b*

CD 93.42 -7.26 44.48

0.25 C25 91.25 -7.25 54.61

C50 89.01 -7.09 69.49

CD 91.01 -6.05 67.38 Reactive Yellow 143 1 C25 88.63 -5.25 73.67

C50 85.2 -2.39 85.4

CD 87.31 -0.93 90.36

4 C25 85.46 -0.49 88.48

C50 82.9 4.36 95.58

CD 82.63 17.3 58.12

0.25 C25 81.56 15.9 58.48

C50 80.27 17.45 63.25

CD 75.19 29.57 73.7 Reactive Yellow 206 1 C25 75.03 24.3 69.31

C50 71.7 31.5 77.33

CD 66.87 41.5 79.93

4 C25 68.42 30.34 73.49

C50 64.39 42.06 78.52

Table 33 Continued

CD 86.64 8.56 53.54

0.25 C25 84.6 9.04 56.61

C50 83.6 11.55 64.45

CD 80.22 19.12 72.59 Reactive Yellow 168 1 C25 78.46 18.14 69.69

C50 76.04 22.95 78.61

CD 72 30.89 83.87

4 C25 71 26.38 76.79

C50 67.3 32.76 79.96

CD 65.06 42.07 -7.96

0.25 C25 63.53 45.83 -8.37

C50 57.54 53.57 -7.56

CD 51.48 53.46 -5.96 Reactive Red 238 1 C25 53.08 55.28 -6.1

C50 45.14 60.6 0.58

CD 39.83 57.1 0.92

4 C25 44.99 58.53 -1.74

C50 38.28 58.65 7.8

Table 33 Continued

CD 59.12 50.32 12.76

0.25 C25 59.19 52.08 14.21

C50 56.84 56.55 19.15

CD 46.3 56.15 21.6 Reactive Red 266 1 C25 49.75 57.86 22.45

C50 45.62 58.66 28.93

CD 38.4 54.12 26.28

4 C25 42.43 57.41 27.02

C50 39.07 56.04 31.72

CD 60.09 -3.76 -23.12

0.25 C25 59.86 -4.54 -23.45

C50 54.45 -3.55 -29.18

CD 43.65 -2.27 -28.82 Reactive Blue 235 1 C25 45.13 -3.2 -27.57

C50 37.59 0.58 -32.35

CD 27.93 2.78 -28.8

4 C25 33.14 -0.63 -28.35

C50 26.18 3.78 -28.45

Table 33 Continued

CD 59.85 -10.69 -33.24

0.25 C25 60.78 -11.68 -31.88

C50 54.69 -14.35 -36.98

CD 44.45 -6.7 -39.77 Reactive Blue 268 1 C25 48.98 -10.59 -36.67

C50 38.15 -4.89 -40.95

CD 31.13 2.18 -40.29

4 C25 37.21 -3.4 -38.52

C50 27.64 2.55 -37.46

CD 41.22 1.05 -4.5

0.5 C25 39.45 3.17 -3.68

C50 30.86 0.2 -6.71

Novacron super CD 23.73 1.78 -2.88

Black R 2 C25 25.98 3.25 -3

C50 19.58 2.01 -2.16

CD 16.5 1.25 -1.11

8 C25 18.22 1.95 -2.36

C50 15.51 1.79 -0.49

Table 33 Continued

CD 41.61 -3.97 -2.96

0.5 C25 40.78 -3.84 -1.82

C50 30.7 -4.16 -4.46

CD 24.2 -2.42 -2.14 Novacron super 2 C25 27.22 -2.77 -1.74 Black G C50 20.03 -1.36 -1.39

CD 16.44 -0.05 -0.82

8 C25 19.85 -1.73 -2.57

C50 15.94 0.29 -0.42

CD 85.1 12 48.4

0.25 C25 84.34 10.95 48.7

C50 81.66 16.24 61.59

Remazol Golden CD 77.54 22.72 65.31

Yellow RGB 1 C25 77.84 20.04 61.82

C50 73.97 27.4 75.07

CD 68.17 34.22 76.89

4 C25 70.68 28.2 70.63

C50 64.57 37.35 76.35

Table 33 Continued

CD 65.97 42.81 -5.67

0.25 C25 63.93 44.89 -5.96

C50 57.2 54.52 -5.55

CD 52.48 54.96 -2.81 Remazol Red RGB 1 C25 54.31 53.05 -3.82

C50 46.16 59.42 1.26

CD 40.65 58.67 5.12

4 C25 44.61 58.79 1.71

C50 38.17 57.47 9.1

CD 59.45 -10.14 -14.56

0.25 C25 56.33 -10.71 -16.1

C50 52.94 -12.03 -18.4

CD 41.4 -10.83 -17.64 Reactive Blue 250 1 C25 42.03 -10.76 -17.95

C50 33.23 -9.36 -18.53

CD 24.02 -5.95 -14.32

4 C25 27.75 -7.64 -16.21

C50 20.99 -4.08 -12.32

Table 33 Continued

CD 81.34 -22.82 -13.33

0.25 C25 80.39 -24.57 -11.93

C50 76.97 -28.38 -17.06

CD 71.25 -29.08 -21 Reactive Blue 21 1 C25 70.88 -31.62 -17.95

C50 63.22 -36.17 -25.65

CD 58.2 -33.56 -27.01

4 C25 62.25 -36.27 -19.07

C50 50.02 -34.12 -28.09

CD 85.25 11.61 57.84

0.25 C25 82.2 14.26 62.99

C50 81.59 17.35 66.35

CD 78.46 23.79 77.17 Reactive Yellow 125 1 C25 78.44 20.59 75.8

C50 74.32 30.39 82.73

CD 71.39 34.79 86.51

4 C25 71.28 29.79 82.59

C50 66.6 40.7 83.39

Table 33 Continued

CD 67.36 44.89 -6.4

0.25 C25 65.29 43.81 -8.34

C50 60.89 53.5 -6.97

CD 54.63 58.17 -3.06 Reactive Red 147 1 C25 56.06 54.03 -6.91

C50 48.83 62.76 0.33

CD 43.25 63.05 6.28

4 C25 44.16 60.35 -0.28

C50 40.96 62.17 9.77

CD 63.78 -4.27 -22.82

0.25 C25 60.44 -4.04 -23.78

C50 57.3 -3.23 -27.19

CD 46.2 -2.39 -29.3 Reactive blue 209 1 C25 45.26 -1.89 -29.47

C50 38.43 0.64 -33.6

CD 29.6 2.95 -30.64

4 C25 30.98 2.1 -30.4

C50 24.61 5.62 -29.45

Table 33 Continued

CD 84.78 13.08 52.91

0.25 C25 83.64 11.51 54.54

C50 80.23 19.22 69.06

CD 77.6 24.65 70.41 Reactive Yellow 176 1 C25 77.03 21.22 67.92

C50 72.04 29.58 77.47

CD 70.59 34.8 78.54

4 C25 70.2 28.89 73.11

C50 64.64 38.48 77.29

CD 65.75 44.97 -7.72

0.25 C25 64.28 44.95 -8.14

C50 59.05 51.88 -9.59

CD 51.83 58.4 -4.18 Reactive Red 197 1 C25 53.5 54.92 -5.79

C50 45.4 58.84 -2.08

CD 41.71 61.25 4.04

4 C25 44.06 59.41 -0.26

C50 37.84 56.66 6.78

Table 33 Continued

CD 51.84 -7.13 -15.39

0.25 C25 51.76 -7 -15.38

C50 40.02 -5.76 -19.55

CD 32.84 -5.78 -16.89 Reactive Black 5 1 C25 35.31 -6.55 -16.62

C50 26.14 -3.15 -15.92

CD 19.28 -1.35 -10.67

4 C25 22.59 -3.3 -12.98

C50 17.99 -0.64 -8.8

CD 84.39 14.23 51.82

0.25 C25 83.04 12.45 51.91

C50 81.83 17.26 61.98

CD 76.39 27.24 71.46 Reactive Orange 70 1 C25 75.74 21.73 65.47

C50 73.62 30.08 77.15

CD 67.05 39.76 79.49

4 C25 65.01 28.3 68.82

C50 64.02 40 77.82

Table 33 Continued

CD 64.87 43.54 -11.12

0.25 C25 59.58 47.13 -10.51

C50 56.61 55.47 -9.35

CD 50.95 55.53 -8.06 Reactive Red 243 1 C25 48.36 55.22 -8.49

C50 45.26 62.28 -1.29

CD 37.76 57.81 2.37

4 C25 38.64 55.72 -4.18

C50 36.99 58.95 8.62

CD 67.54 -4.27 -19.24

0.25 C25 57.85 -3.82 -22.37

C50 55.17 -4.02 -27.69

CD 49.2 -3.76 -26.04 Reactive Blue 52 1 C25 49.31 -3.33 -24.71

C50 38.76 -0.37 -30.71

CD 31 1.18 -28.42

4 C25 37.01 -1.14 -27.43

C50 25.63 3.99 -27.76

Table 33 Continued

CD 63.26 -10.04 -14.31

0.25 C25 59.59 -9.51 -15.43

C50 50.4 -9.77 -19.79

CD 45.37 -10.48 -17.95 Reactive Blue 214 1 C25 43.92 -9.9 -17.89

C50 34.68 -7.44 -19.7

CD 26.43 -6.15 -15.44

4 C25 29.27 -8.02 -16.28

C50 23.05 -3.78 -14.78

4.4 Repeatability in dyeing cationized cotton

In order to create a database for cationized cotton it was necessary to check if the dyed cationized cotton samples were repeatable. For this test, fifteen samples were dyed again for Reactive Yellow 176, Reactive Red 197 and Reactive Black 5 at

0.25, 0.5, 1, 2 and 4 % shades for 50 g/L CHPTAC and this new set of samples (Set 2) was then compared to the previously dyed samples (Set 1). The results are summarized in table 34. From the results, fourteen of the fifteen samples dyes matched each other with ΔE CMC values less than one. Some samples were as close

with a ΔE CMC value of 0.08. Thus it can be concluded that the shades on cationized cotton samples are consistent, reproducible and repeatable.

Table 34: Repeatability in Dyeing Cationized Cotton on 50 g/L CHPTAC fabric

Name Set L* a* b* ΔE CMC Passed/Failed

Reactive Yellow 1 80.23 19.22 69.06 0.72 Passed 176 (0.25%) 2 80.73 18.69 67.03

Reactive Yellow 1 76.05 26.42 74.94 0.65 Passed 176 (0.5%) 2 76.61 25.37 74.35

Reactive Yellow 1 72.04 29.58 77.47 0.47 Passed 176 (1%) 2 72.26 31.36 78

Reactive Yellow 1 68.19 35.6 78.58 0.18 Passed 176 (2%) 2 68.36 35.34 78.12

Reactive Yellow 1 64.64 38.48 77.29 0.29 Passed 176 (4%) 2 64.49 38 76.56

Reactive Red 197 1 59.05 51.88 -9.59 1.26 Failed (0.25%) 2 57.26 54.34 -9.08

Reactive Red 197 1 51.86 57.3 -6.8 0.08 Passed (0.5%) 2 51.89 57.51 -6.78

Table 34 Continued

Reactive Red 197 1 45.4 58.84 -2.08 0.58 Passed (1%) 2 46.33 58.52 -2.72

Reactive Red 197 1 41.1 58.02 2.26 0.55 Passed (2%) 2 41.79 57.88 1.48

Reactive Red 197 1 37.84 56.66 6.78 0.5 Passed (4%) 2 38.48 56.98 6.2

Reactive Black 5 1 40.02 -5.76 -19.55 0.56 Passed (0.25%) 2 40.4 -5.9 -20.4

Reactive Black 5 1 32.62 -4.76 -18.37 0.34 Passed (0.5%) 2 32.4 -4.74 -18.84

Reactive Black 5 1 26.14 -3.15 -15.92 0.67 Passed (1%) 2 26.66 -3.41 -16.72

Reactive Black 5 1 21.3 -1.85 -12.42 0.76 Passed (2%) 2 21.65 -1.93 -13.34

Reactive Black 5 1 17.99 -0.64 -8.8 0.88 Passed (4%)

4.5 Comparison of dye bath exhaustion

Figure 31-33 compares the dye bath exhaustion for Reactive Yellow 176,

Reactive Red 197 and Reactive Black 5 dyes. The dye bath exhaustion for C50 samples is constantly high for all the shades and dyes compared to the corresponding CD samples. The amount of dye left after the dyeing cycle for C50 samples is negligible compared to CD samples. The dye bath exhaustion for C25 is high initially but falls with increasing amount of dye as lesser amount of dye gets exhausted due to limited number of cationic sites. Hence, with appropriate level of cationic treatment it is possible to achieve complete dye exhaustion.

Reactive Yellow 176 100 94.2 90 85.4 85.7 81.3 78.6 80 CD 70.9 68.1 70 60.1 60 C50 50.5 50 40 C25

30 % % exhausionDye 20 10 0 0.25 1 4 % Shade

Figure 34: Dye exhaustion for Reactive Yellow 176

Reactive Red 197 120

95.6 92.9 100 88.8 83.2 84.6 80 75.2 72.9 CD 61.7 60 52.6 C50 C25

40 % % exhausionDye 20

0 0.25 1 4 % Shade

Figure 35: Dye Exhaustion for Reactive Red 197

Reactive Black 5 95.01 100 92.8 91.3 90 85.9 82.9 80 75.2 65.9 70 62.7 CD 60 50.9 50 C50 40 C25

30 %exhausion Dye 20 10 0 0.25 1 4 % Shade

Figure 36: Dye Exhaustion for Reactive Black 5

4.6 Comparison of fastness test ratings

From Tables 35 and 36 it can be seen that the fastness ratings for wash and crocking are best for the C25 samples. The ratings for C50 samples are comparable or slightly less than CD samples, probably because C50 samples contain more dye.

The cationized cotton samples were not scoured after the dye process in spite of which they have better ratings than conventionally dyed and scoured samples.

Table 35: Wash Fastness Test Results

Dye % Shade CD C25 C50

0.25 5 5 5

Reactive Yellow 143 1 4.5 5 4.5

4 4.5 4.5 4.5

0.25 5 5 5 Reactive Yellow 206 1 4.5 4.5 4.5

4 4 4.5 4

0.25 5 5 5 Reactive Yellow 168 1 5 5 5

4 4.5 5 4.5

Table 35 Continued

0.25 5 5 5 Reactive Red 238 1 4.5 5 4.5

4 3.5 4 4

0.25 4.5 5 5 Reactive Red 266 1 3.5 4.5 4

4 3 4 3.5

0.25 5 5 5 Reactive Blue 235 1 4.5 5 4.5

4 3.5 4.5 4

0.25 5 5 5 Reactive Blue 268 1 4.5 5 4.5

4 3.5 4.5 4

0.5 4.5 5 4.5

Novacron Super Black R 2 4 4.5 4

8 3 4 3

0.5 4.5 5 4.5

Novacron Super Black G 2 3.5 4.5 4

8 3 4 3

Table 35 Continued

0.25 5 5 5 Remazol Golden Yellow 1 4.5 5 5 RGB 4 4 4.5 4

0.25 4.5 5 5

Remazol Red RGB 1 3.5 5 4.5

4 3 4 3.5

0.25 4.5 5 4.5 Reactive Blue 250 1 4 4.5 4

4 3 4.5 3

0.25 5 5 5 Reactive Blue 21 1 4 4.5 4

4 3 4.5 3.5

0.25 5 5 5 Reactive Yellow 125 1 5 5 5

4 4 5 4.5

0.25 5 5 5 Reactive Red 147 1 4 4.5 4

4 3 4 3.5

Table 35 Continued

0.25 5 5 5 Reactive blue 209 1 4.5 5 4.5

4 3.5 4.5 4

0.25 5 5 5 Reactive Yellow 176 1 4.5 5 5

4 4 4.5 4.5

0.25 5 5 5 Reactive Red 197 1 5 5 5

4 4.5 4.5 4.5

0.25 4.5 5 5 Reactive Black 5 1 4.5 5 4.5

4 4 4.5 4.5

0.25 5 5 5 Reactive Orange 70 1 5 5 5

4 4 4.5 4

0.25 5 5 5 Reactive Red 243 1 4 5 4.5

4 3 4 3.5

Table 35 Continued

0.25 4.5 5 5 Reactive Blue 52 1 4 5 4.5

4 3 4 3.5

0.25 4.5 5 5 Reactive Blue 214 1 4.5 4.5 4

4 3.5 4 3.5

Table 36: Crock Fastness Test Results

Dye % Shade CD C25 C50

Dry Wet Dry Wet Dry Wet

0.25 5 5 5 5 5 4.5

Reactive Yellow 143 1 4.5 4 5 4.5 4.5 4

4 3.5 3 4.5 4.5 4 3.5

0.25 4.5 4.5 5 5 5 4.5 Reactive Yellow 206 1 3.5 3 4.5 4.5 4.5 4

4 2.5 2 4.5 4 4 3

Table 36 Continued

0.25 4.5 4.5 5 5 4.5 4.5 Reactive Yellow 168 1 4 3 4.5 4 4 3.5

4 3 2.5 4.5 4 3.5 3

0.25 5 4.5 5 5 5 5 Reactive Red 238 1 4 3.5 5 4.5 4 4

4 3 3 4.5 4.5 3.5 3

0.25 4 4 5 5 4.5 4.5 Reactive Red 266 1 3.5 3 4.5 4 4 3.5

4 2 2 4 4 3.5 3

0.25 5 5 5 5 5 5 Reactive Blue 235 1 4.5 4 5 4.5 4.5 4

4 3.5 3 4.5 4 4 3

0.25 4.5 4.5 5 5 5 4.5 Reactive Blue 268 1 4 3.5 4.5 4.5 4 4

4 3 3 4 4 3.5 3

0.5 4.5 4 5 5 4.5 4.5 Novacron super Black 2 3.5 3 4.5 4 4 3.5 R 8 2.5 2.5 4 4 3.5 3

Table 36 Continued

0.5 4.5 4 5 5 4.5 4.5 Novacron super Black 2 3.5 3 4.5 4 4 3.5 G 8 2.5 2 4 3.5 3 2.5

0.25 5 5 5 5 5 5 Remazol Golden 1 4.5 4 5 4.5 4.5 4.5 Yellow RGB 4 3.5 3.5 4 4 4 3.5

0.25 4.5 4.5 5 5 5 4.5

Remazol Red RGB 1 4 3.5 5 4.5 4 4

4 3 3 4 4 3.5 3

0.25 5 5 5 5 5 5 Reactive Blue 250 1 4.5 4.5 5 5 4.5 4

4 3.5 3 4.5 4 4 3.5

0.25 5 5 5 5 5 5 Reactive Blue 21 1 4.5 4.5 5 5 4.5 4

4 3.5 3 4.5 4 4 3.5

0.25 5 4.5 5 5 5 4.5 Reactive Yellow 125 1 4 3.5 5 4.5 4.5 4

4 3 2.5 4 4 3 3

Table 36 Continued

0.25 5 5 5 5 5 5 Reactive Red 147 1 4 3.5 4.5 4 4.5 4

4 2.5 2 4 3.5 3 2.5

0.25 5 5 5 5 5 4.5 Reactive blue 209 1 4 3.5 5 4.5 4 3.5

4 3 3 4 4 3.5 3

0.25 5 5 5 5 5 4.5 Reactive Yellow 176 1 4.5 4.5 5 4.5 4 4

4 3.5 3.5 4.5 4 4 3.5

0.25 5 4.5 5 5 4.5 4.5 Reactive Red 197 1 4 4 5 4 3.5 3.5

4 3 2.5 4.5 3.5 3 3

0.25 5 4.5 5 5 4.5 4.5 Reactive Black 5 1 4 4 5 4.5 4 3.5

4 3 3 4.5 4 3.5 3

0.25 5 5 5 5 5 5 Reactive Orange 70 1 4.5 4 5 4.5 4.5 4

4 3 3 4.5 4.5 3.5 3

Table 36 Continued

0.25 5 5 5 5 5 4.5 Reactive Red 243 1 4.5 4.5 5 5 4.5 4

4 3 2.5 4.5 4 4 3.5

0.25 5 5 5 5 5 5 Reactive Blue 52 1 4.5 4 5 5 4.5 4

4 4 3.5 4.5 4.5 4 3.5

0.25 5 5 5 5 5 4.5 Reactive Blue 214 1 4.5 4 4.5 4.5 4.5 3.5

4 3.5 3 4.5 4 3.5 3

4.7 Color matching using conventional and cationized primaries

After creating the colorant databases it was necessary to evaluate the performance of the newly developed cationized cotton primaries and compare them to the traditional conventional primaries. In Table 37, four standards (targets),

Green Thumb (GT), Solar Wind (SW), Stained Wood (ST) and Heavy-Hearted (HH) were selected for color matching and their reflectance spectra were measured.

Two recipes, one from the cationized primaries and the other from conventional primaries were obtained and both were dyed on cationized cotton. The evaluation was based on the ΔECMC values i.e. which set of primaries gave a closer match to the target. Green Thumb, Solar Wind and Stained Wood samples were dyed on 25 g/L

CHPTAC treated fabric and its primaries because C50 primaries would need less dye which would lead to patchy dyed samples. Heavy-Hearted samples were dyed using

50 g/L CHPTAC treated fabric and its primaries as the calculated amount of dye required to dye was much less than CD primaries and uniform dyed samples were obtained.

Table 37: Recipes for dyeing the standards (targets)

Shades Green Thumb Stained Wood Solar Wind Heavy-hearted

Remazol G. 0.56 1 ------2.12 Yellow RGB

Remazol Red 0.15 0.67 ------2.80 RGB

Reactive Blue 1.00 ------21

Reactive Blue ------0.39 ------0.28 250 (150%)

Reactive ------0.31 ------Yellow 168

Reactive Red ------0.052 ------266

Reactive Blue ------0.065 ------235

Total 1.71 2.06 0.427 5.2

L* 57.22 45.39 62.34 36.04

a* -11.57 8.58 6.63 28.08

b* 10.95 6.02 19.29 10.12

Table 38: Auxiliaries for Dyeing the Standards

Auxiliaries Green Stained Heavy- Solar

(g/L) Thumb Wood Hearted Wind

Marsperse 6000 1.5 1.5 1.5 1.5

Sodium Sulfate 30 30 60 30

Soda Ash 20% 8 10 18 8

Table 39: Dyeing Procedure for the Standards.

Shade Procedure

Prepare dyes @ 150°F. Add dye, Marsperse® 6000 and sodium

Green Thumb sulfate. Ramp to 175°F @ 3°F/min. Hold 30 min. Add sodium

Stained Wood carbonate (in two portions) over 15 min. Hold 45 min. Drop.

Heavy-Hearted Rinse warm and soap-off 10 min. @ 200°F with 1.0 g/L

Marsperse® 6000. Cold rinse, extract and dry.

Prepare dye at 150°F. Add dye, aux chemicals (except soda ash)

and salt. Heat to 100°F. Hold 35 minutes. Ramp to 140°F @

4°F/min. Hold 30 min. Add soda ash (in two portions) over 15 Solar Wind minutes. Hold 30 minutes. Drop. Rinse warm and soap 10

minutes @200°F with 1.0 g/L Marsperse 6000. Rinse cold,

extract and dry.

From Table 40-43, Green Thumb shades were dyed using Reactive Yellow 125,

Reactive Red 147 and Reactive Blue 209, Stained Wood shades were dyed using

Reactive Yellow 176, Reactive Red 197 and Reactive Black 5, Heavy-Hearted shades were dyed using Reactive Orange 70, Reactive Red 243 and Reactive Blue 52 and

Solar Wind shades were dyed with Reactive Yellow 168, Reactive Red 266 and

Reactive Blue 235. The results were obtained by dyeing cationized cotton with recipes obtained using C25 or C50 primaries (sample 1) and CD primaries (sample

2) on cationized cotton and no further correction was applied to these samples as this was an attempt to compare the performance of the primaries to obtain a closer match and not to actually match the shade. From the ΔECMC values it can be concluded that the new cationized samples gave a closer match to the target than the conventional primaries. For the Green Thumb shade, a close match was obtained in the first attempt itself whereas for the other shades the samples dyed with cationized primaries gave much better results compared to conventional primaries.

The new primaries calculated the amounts of dye based on the shade obtained by the individual dyes on the cationized cotton thus taking into account of the appearance in change of hue.

Table 40: Recipes for Dyeing Green Thumb Shades

Green Thumb Sample 1 Sample 2

Fabric Treatment 25 g/L CHPTAC 25 g/L CHPTAC

Primaries Cationized primaries Traditional primaries

Reactive Yellow 125 0.2611 0.3128

Reactive Red 147 0.0065 0.0063

Reactive Blue 209 0.4507 0.4946

Total dye % 0.7183 0.8137

DL* 0.36 L -0.47 D

Da* -0.71 G -1.19 G

Db* -0.31 B -1.97 B

ΔE CMC 0.68 2.06

Table 41: Recipes for Dyeing Stained Wood Shades

Stained Wood Sample 1 Sample 2

Fabric Treatment 25 g/L CHPTAC 25 g/L CHPTAC

Primaries Cationized primaries Traditional primaries

Reactive Yellow 176 0.3313 0.38

Reactive Red 197 0.2636 0.2735

Reactive Black 5 0.156 0.1575

Total dye % 0.7509 0.811

ΔL* 3.60 L 3.04 L

Δa* -2.52 G -1.89 G

Δb* -1.39 B 5.57 Y

ΔE CMC 2.96 8.33

Table 42: Recipes for Dyeing Solar Wind Shades

Solar Wind Sample 1 Sample 2

Fabric Treatment 25 g/L CHPTAC 25 g/L CHPTAC

Primaries Cationized primaries Traditional primaries

Reactive Yellow 168 0.2241 0.1885

Reactive Red 266 0.0351 0.0506

Reactive Blue 235 0.0557 0.0854

Total dye % 0.3149 0.3245

ΔL* 0.43 L -2.36 D

Δa* -0.93 G 0.06 R

Δb* 0.16 Y -5.53 B

ΔE CMC 1.2 4.22

100

Table 43: Recipes of Dyeing Heavy-Hearted Shades

Heavy-hearted Sample 1 Sample 2

Fabric Treatment 50 g/L CHPTAC 50 g/L CHPTAC

Primaries Cationized primaries Traditional primaries

Reactive Orange 70 0.4987 0.7264

Reactive Red 243 0.5566 1.3987

Reactive Blue 52 0.1214 0.3058

Total dye % 1.1767 2.4309

ΔL* 1.89 L -4.18 D

Δa* -1.51G -7.08 G

Δb* -2.31 B -2.31 B

ΔE CMC 2.09 4.7

101

Color match for the Green Thumb, Stained Wood and Heavy-Hearted was also attempted using Remazol Golden Yellow RGB, Remazol Red RGB and Reactive Blue

21 and the results are summarized in Tables 44-46. The recipes obtained from these primaries on cationized cotton (sample1) could not give a close match to the target. The process was repeated by applying correction by reading the sample dyed with predicted recipe and the correction was calculated by the software. The corrections were applied to the recipes (sample 2) however there was not enough improvement. Remazol Golden Yellow RGB is a mixture of a yellow and red dye and

Remazol Red RGB is a mixture of red and blue dye. Hence, the probable reason for not attaining a closer match could be that due to the presence for more than three dyes in the dye bath, it complicates the prediction of the shade obtained by these mixtures of dyes as the cationized cotton may have preferential affinity for a certain dye. This can be seen from Table 44 that even after reducing the concentration of the Remazol Red RGB dye in bath in the second attempt the sample appears redder may be due to a preferential affinity toward the red dye present in Remazol Golden

Yellow RGB. This can be regarded as one of the drawbacks for color matching on cationized cotton.

102

Table 44: Recipes for Dyeing Green Thumb Shades with Remazol Dyes

Green Thumb Sample 1 Sample 2 Sample 3

Fabric 25 g/L CHPTAC 25 g/L CHPTAC 25 g/L CHPTAC Treatment

Traditional Primaries Cationized primaries Cationized primaries primaries

Remazol G. 0.2941 0.2941 0.3164 Yellow RGB

Remazol Red 0.0991 0.0824 0.0921 RGB

Reactive Blue 0.7445 0.7968 0.8628 21

Total dye % 1.1377 1.1733 1.2713

ΔL* 2.49 L 0.57 L -2.31 D

Δa* 1.83 R 2.25 R -1.04 G

Δb* 0.58 Y 0.32 Y 0.98 Y

ΔE CMC 1.95 1.89 1.38

103

Table 45: Recipes for Dyeing Stained Wood Shades with Remazol Dyes

Stained Wood Sample 1 Sample 2 Sample 3

Fabric 25 g/L CHPTAC 25 g/L CHPTAC 25 g/L CHPTAC Treatment

Cationized Cationized Traditional Primaries primaries primaries primaries

Remazol G. 0.426 0.509 0.45 Yellow RGB

Remazol Red 0.2804 0.276 0.3217 RGB

Reactive Blue 0.186 0.196 0.2371 250 (150%)

Total dye % 0.8924 0.981 1.0088

ΔL* 5.29 L 3.78 L 3.31 L

Δa* -2.55 G -2.13 G -1.98 G

Δb* 3.00 Y 2.88 Y 2.57 Y

ΔE CMC 6.55 5.75 5.21

104

Table 46: Recipes of Dyeing Heavy-Hearted Shades with Remazol Dyes

Heavy-hearted Sample 1 Sample 2 Sample 3

Fabric 50 g/L CHPTAC 50 g/L CHPTAC 50 g/L CHPTAC Treatment

Traditional Primaries Cationized primaries Cationized primaries primaries

Remazol G. 0.4896 0.4896 1.1409 Yellow RGB

Remazol Red 0.5864 0.4358 1.6095 RGB

Reactive Blue 0.1175 0.114 0.1879 250 (150%)

Total dye % 1.1935 1.0394 2.9383

ΔL* 1.18 L 1.80 L -4.19 D

Δa* 0.90 R -1.69 G 1.29 R

Δb* -3.04 B -2.66 B 0.51 Y

ΔE CMC 2.75 2.31 2.42

105

5. Conclusions

The use of cationized cotton can overcome the existing environmental problems pertaining to conventional dyeing of cotton with reactive dyes. It is possible to successfully dye cotton without the use of salt with shorter dyeing cycles and obtain higher color yields. An appropriate concentration of CMC needs to be used depending on the concentration of CHPTAC on the fabric to obtain uniformly dyed samples. As the concentration of CHPTAC increases the dye exhaustion also increases thus reducing the effluent load. However, it is difficult to obtain uniform dyeing with high concentrations of CHPTAC and low concentrations of dye. This problem can be overcome by increasing the concentration of CMC in the bath.

It is seen that the behavior of each dye is different on cationized cotton. The exhaustion pattern for each dye varies and cationized cotton may have higher affinity for certain dyes. From this behavior it can be concluded that the dye molecular structure plays an important role when dyeing cationized cotton. Certain dyes undergo changes in hue when dyed on cationized cotton which makes it difficult using the existing color matching recipes on cationized cotton. Thus it was necessary to create a separate database for cationized cotton. The dyeing of cationized cotton proved to be repeatable and the color attributes remain consistent. The fastness properties of the cationized cotton dyed samples are better or comparable to the conventionally dyed samples. Hence, the scouring and rinsing

106

stages can be eliminated by which significant amounts of water, time and energy can be saved.

The newly developed cationized cotton primaries gave better color matching results (i.e. smaller color difference between the standard and the trial) compared to conventional primaries. However, the desired results could not be obtained in case of dye baths containing more than three dye components. The amount of dye calculated using C50 primaries is much less compared to the amount calculated from conventional primaries. The amount of dye calculated using C25 primaries is comparable to the conventional primaries since the extent to which dyes get exhausted in both is nearly same. The C25 primaries can be used for lighter shades while the C50 primaries can be used for darker shades.

107

6. Recommendations for Future Work

These studies show that cationized cotton can be successfully dyed without the use of salt. The change in the appearance of shades can be account for by creating new primaries for cationized cotton. As discussed earlier, the behavior of each dye is different on cationized cotton. It is necessary to study the interaction between different dye structures and cationized cotton.

For higher concentrations of CHPTAC and less amount of dye, active cationic sites may be left on the fabric which can undergo cross staining while laundering with other fabrics. After the dyeing stage, the process of capping can block the unoccupied cationic site and prevent it from picking up loose dye during laundering.

A relationship between the cationization treatment and amount of dye is needed to calculate the exact amount of cationized agent can be applied just enough to exhaust all the dye present in the bath and also obtain uniform dyeing by using appropriate amount of leveling agent. A mathematical model needs to be developed that will allow to optimize the cationization level for a specific dye formula.

For this current work to be successful it is also necessary to carry out color matching on bulk scale and test for consistency and uniform dyeing.

108

REFERENCES

1. Morton, Jill. Why Color Matters [WWW page]. URL

http://www.colorcom.com/research/why-color-matters

2. Farrell, Matthew J. “Sustainable Cotton Dyeing.” PhD’s Thesis, North Carolina

State University at Raleigh, 2011.

3. Tabba, Adham, “cationization of Cotton with 2, 3-

Epoxypropyltrimethylammonium Chloride.” Master’s Thesis, North Carolina

State University at Raleigh, 2000.

4. Bashar, M M. and Khan, M A. “An Overview on Surface Modification of Cotton

Fiber for Apparel Use.” Journal of Polymers and the Environment. 21. (2013):

181-190.

5. Textile Fibers, Dyes, Finished and Processes. H. L. Needles. U.S.A.: Noyes

Publications, 1986.

6. Chemistry of Textiles Fibers. R. R. Mather and R.H. Wardman. Cambridge: The

Royal Society of Chemistry, 2011.

7. Basic Principles of Textile Coloration. Arthur D Broadbent. England: Society of

Dyers and Colourists, 2001.

8. Hashem, Mohamed M. “Development of a One‐Stage Process for Pretreatment

and Cationisation of Cotton Fabric.” Coloration Technology. 122. (2006): 135‐

144.

109

9. Industrial dyes: Chemistry, Properties, Applications. Ed. Klaus Hunger.

Weinheim; [Cambridge]: Wiley-VCH, 2003.

10. Gillingham, Estelle L., et al. “Co‐application of Hydroxyalkyl Dyes and

Polyphosphonic Acids to Cotton to Achieve Dye‐Fibre Covalent Bonding.”

Coloration Technology. 117. (2001): 318‐322.

11. Dyeing and Chemical Technology of Textile Fibers. E. R. Trotman. Fourth ed.

London: Charles Griffin & Co. Ltd, 1970.

12. Textile Fibers, Dyes, Finishes and Processes. Ed. Howard L. Needles. New Jersey:

Noyes Publications, 1986.

13. Warburton Jr. C. E. “Crockfastness of Polyacrylate Textile Pigment-Printing

Binders: Effect of Binder Mechanical Properties and Adhesion to Fabric.” The

Journal of Adhesion. 7(2). (1975): 109-119.

14. Vankar, Padma S. “Chemistry of Natural Dyes.” Resonance. 5(10). (2000): 73-80.

15. Colorants for Non-Textile Applications. Ed. H.S. Freeman and A.T. Peters.

Elsevier Science B.V., 2000.

16. Taylor, G. W. “Natural dyes in Textile Applications.” Journal of Society of Dyers

and Colourists. 16(1). (1986): 53-61.

17. Gulrajani, M. L., et al. “Colour Gamut of Natural Dyes on Cotton Yarns” Coloration

Technology. 117. (2001): 225-228.

110

18. Farrell, Matthew J. “Color Matching and Utilization of Teegafix High Efficiency

Fiber Reactive dyes in a Production Setting.” Master’s Thesis, North Carolina

State University at Raleigh, 2007.

19. Montazer, M., et al. “Salt Free Reactive Dyeing of Cationized Cotton.” Journal of

Fibers and Polymers. 8(6). (2007): 608-612.

20. Zhang, Shufen, et al. “Pretreatment of Cotton with Poly(vinylamine chloride) for

Salt-free Dyeing with Reactive Dyes” Coloration Technology. 121. (2005): 193-

197.

21. Kannan, M. S. S., et al. “Influence of Cationization of Cotton on Reactive Dyeing.”

Journal of Textile and Apparel Technology and Management. 5(2). (2006): 1-16.

22. Cook, Fred L. “Salt Requirements Put Pressure on Wet Processing Plants.” Textile

World. 144(8). (1994): 83‐86.

23. Bradbury, Mike, et al. “Smart Rinsing: A Step Change in Reactive Dye Application

Technology”. Journal of the Society of Dyers and Colourists. 116. (2000): 144-

147.

24. Thiry, Maria. “Color It Greener.” AATCC Review. May/June 2010, p34.

25. Hashem, Mohamed, et al. “Reaction Efficiency for Cellulose Cationization Using

3‐Chloro‐2‐Hydroxypropyl Trimethyl Ammonium Chloride.” Textile Research

Journal. 73(11). (2003): 1017‐1023.

111

26. Hauser, Peter J. and Adham H. Tabba. “Improving the Environmental and

Economic Aspects of Cotton Dyeing Using a Cationized Cotton.” Coloration

Technology. 117. (2001): 282‐288.

27. Hauser, Peter J. and Adham H. Tabba. “Dyeing Cationized Cotton with Fiber

Reactive Dyes: Effect of Reactive Chemistries.” AATCC Review. May 2002.

28. Hauser, Peter J. and Mehmet Kanik. “Printing of Cationized Cotton with Acid

Dyes.” AATCC Review. March 2003.

29. Kanik, Mehmet and Peter J. Hauser. “Printing of Cationized Cotton with Reactive

Dyes.” Coloration Technology. 118. (2002): 300‐306.

30. Kanik, Mehmet and Peter J. Hauser. “Ink‐jet Printing of Cationized Cotton Using

Reactive Inks.” Coloration Technology. 119. (2003): 230‐234.

31. Kanik, Mehmet, et al. “Effect of Cationization on Inkjet Printing Properties of

Cotton Fabrics.” AATCC Review. June 2004.

32. Kanik, Mehmet and Peter J. Hauser. “Printing Cationized Cotton with Direct

Dyes.” Textile Research Journal. 74(1). (2004): 43‐50.

33. Karnik, Poonam, “Use of Cationized Cotton for Textile Effluent Color Reduction.”

Master’s Thesis, North Carolina State University at Raleigh, 2002.

34. Steen, Daniel, et al. “Defining a Practical Method of Ascertaining Textile Color

Acceptability.” Color Research & Application. 27(6). (2002): 391-398.

35. Color Physics for Industry. Ed. Roderick McDonald. Second ed. England: Society

of Dyers and Colourists, 1997.

112

36. Industrial Color Physics. Georg A. Klein. New York: Springer, 2010.

37. Chattopadhyay, D. P., et al. “Salt-free Reactive Dyeing of Cotton.” International

Journal of Clothing Science and Technology. 19(2). (2007): 99-108.

38. Wei, Ma, et al. “Preparation of Cationic Cotton with two-bath Pad-bake Process

and its Application in Salt-free Dyeing.” Carbohydrate Polymers. 78(3). (2009):

602-608.

39. Cannon, Kristin M. and Peter J Hauser. “Color Assessment of Cationized Cotton

Dyed with Fiber Reactive Dyes.” AATCC Review. May 2003.

40. Livengood, Charels D., “Spot tests for Identification of Warp Sizes on Fabrics.”

AATCC warp sizing handbook, 1995.

41. Technical Manual of the American Association of Textile Chemists and Colorists.

Research Triangle Park, North Carolina, USA: 2009.

113