Contents
Preface xi
Acknowledgements xiii
Conclusion xv
1. Introduction to textile dyes 1
1.1 Introduction 1
1.2 Manipulating the color and application of dyes 3
1.3 Classification of colorants 7
2. Direct dyes 15
2.1 Introduction 15
2.2 Classification of direct dyes 18
2.3 Application of direct dyes 19
2.4 After-treatment of direct dyed material 20
2.5 Chemical structure of direct dyes 21
2.6 Manufacturing of direct dyes 23
2.7 Identification of direct dyed material 24
2.8 Identification of direct dye powder 25
2.9 Stripping of direct dye from the dyed fabric 25
3. Azoic dyes (Naphthol dyes) 26
3.1 Introduction 26
3.2 Stages of Naphthol dyeing 27
3.3 Advantages of Naphthol dyeing 29
3.4 Disadvantages of Naphthol dyeing 29
3.5 Azo coupling components (Naphthols) 31
3.6 Bases 32
3.7 General dyeing procedure of Naphthol dyes 33
3.8 Dyeing methods 34
4. Sulphur dyes 37
4.1 Introduction 37
4.2 Classification 39
4.3 Application 40
4.4 After treatments 41
4.5 Common problems encountered and remedies 42
4.6 Manufacturing of sulphur dyes 43
4.7 Properties of sulphur dyes 44
4.8 Types of sulphur dyes 45
4.9 Application of sulphur dyes 45
4.10 Dyeing of liquid sulphur black 49
4.11 Main properties of liquid sulphur dyes 52
4.12 Use of spent dye bath in dyeing 53
4.13 Identification of sulphur-dyed material 53
4.14 Identification of sulphur dye powder 53
4.15 Stripping of Sulphur dye from the dyed fabric 53
5. Vat dyes 55
5.1 Introduction 55
5.2 Classification of vat dyes 63
5.7 Classification of vat dyes 64
5.3 Vat dye application methods 65
5.4 Precautions in vat dyeing 66
5.5 Manufacturing of vat dyes 68
5.6 Properties of vat dyes 69
5.7 Problems with anthraquinone dyes 69
5.8 Vat dyes dyeing process 70
5.9 Stripping of vat dyes 71
5.10 Shade rehandling methods 71
6. Chrome dyes (Mordant dyes) 74
6.1 Introduction 74
6.2 What are chrome dyes? 75
6.3 Classification of chrome dyes 75
6.4 Application methods 76
6.5 Properties of mordant dyes 80
6.6 Mechanism of dyeing 81
6.7 Application of mordant dyes 81
6.8 What are the risks with chrome dyes? 83
6.9 Replacement of chrome dyes – Why? 83
7. Metal-complex dyes 85
7.1 Introduction 85
7.2 Classification of metal-complex dyes 86
7.3 Classification of metal-complex dyes 89
7.4 Features of metal-complex dyes 90
7.5 Types of metal-complex dyes 90
7.6 Manufacturing of metal-complex dyes 91
7.7 Application of metal-complex dyes 93
7.8 Dyeing with metal-complex (1: 1) acid dyes 93
7.9 Dyeing with metal-complex 1:2 acid dyes 94
7.10 Stripping of metal-complex dyes 96
8. Acid dyes 97
8.1 Introduction 97
8.2 Chemical structure of acid dyes 99
8.3 Manufacturing of acid dyes 105
8.4 Different types of acid dyes 106
8.5 Mechanism of dyeing with acid dyes 109
8.6 Identification of acid dyes 112
8.7 Stripping of acid dyes 112
9. Basic dyes 113
9.1 Introduction 113
9.2 Manufacturing of basic dyes 120
9.3 Properties of basic dyes 120
9.4 Dyeing of acrylic with basic dyes 121
9.5 Advantages of basic dyes 122
9.6 Limitations of basic dyes 122
9.7 Modified basic dyes 122
9.8 Key advantages over conventional basic dyes 122
9.9 Limitations of basic dye 122
9.10 Modified basic dye 123
9.11 Application of the basic dyes 123
9.12 Stripping of basic dyes 124
10. Indigo dyes 125
10.1 Introduction 125
10.2 Cultivation of indigo dyes 130
10.3 Processing of indigo dyes 130
10.4 For natural indigo dye 131
10.5 For synthetic production of indigo dye 132
10.6 Synthetic indigo dye 134
10.7 Pre-reduced indigo 135
10.8 Natural indigo versus synthetic indigo 135
10.9 Properties of indigo dyes 135
10.10 Dyeing processes 136
10.11 Advantages of rope dyeing against slasher dyeing 137
10.12 Indigo dyeing process flow 137
10.13 What’s ring dyeing? 138
10.14 Manufacturing of indigo dyes 139
10.15 Manufacturing process of Denim 140
11. Pigment dyes 145
11.1 Introduction 145
11.2 Development of synthetic pigments 146
11.3 New sources for historic pigments 147
11.4 Manufacturing and industrial standards 150
11.5 Differences between dyes and pigments 152
11.6 Basic dyes 156
11.7 Fat-soluble dyes 156
11.8 Metal-complex dyes 156
11.9 Dyes for wood coating 156
12. Disperse dyes 160
12.1 Introduction 160
12.2 Characteristics of disperse dyes 162
12.3 Classification of disperse dyes 163
12.4 Properties of disperse dyes 166
12.5 Classification of disperse dyes 167
12.6 Manufacturing of disperse dyes 168
12.7 Application methods of disperse dyes 169
12.8 Dyeing mechanism of disperse dye 169
12.9 Effect of various conditions on disperse dyeing 170
12.10 Carrier dyeing method 170
12.11 High temperature dyeing method 171
12.12 Dyeing of polyester fabric in thermasol dyeing method 172
12.13 New developments in disperse dyes 173
12.14 Stripping of disperse dyes 173
13. Reactive dyes 175
13.1 Introduction 175
13.2 Components of reactive dyes 176
13.3 Types of reactive dyes 177
13.4 Dyeing methods 178
13.5 Reactive dyes categorized by functional group 180
13.6 Classification of reactive dyes (with example) 182
13.7 Advantages of the reactive dyes 183
13.8 Dyeing cycle and important factors/phases in reactive dyeing 183
13.9 Types of reactive dyes 183
13.10 Uses of reactive dyes 184
13.11 Trade names of reactive dyes 184
13.12 Properties of reactive dyes 184
13.13 General structure of reactive dyes 185
13.14 Chemical structure of reactive dyes 185
13.15 Classification of reactive dyes 186
13.16 Manufacturing of reactive dyes 187
13.17 Identification of reactive dyes 189
13.18 Dyeing mechanism of reactive dye 189
13.19 Stripping of reactive dye 190
13.20 Different methods of reactive dye application 191
13.21 Testing of reactive dyes 192
13.22 Current trends in reactive dyes and their application 193
13.23 Future trends in reactive dyes 193
13.24 Reactive dyes for wool 194
Preface
During our college days we used to read a book on “Chemistry of Dyes,” written by Prof Dr Venkatraman. That was into many volumes and very big in size. It was a Bible for students studying Dyestuff Chemistry. But the students found it very difficult to understand. Then Dr Shenai wrote little simplified books on dyes and application. We read those books in our college time. But all these books became very academic. When we entered the textile industry the scenario was different. The practices adopted in dyes units and textile companies were very different.
Till then nobody from the industry wrote any book on dyes and textiles. So I have put my 30-year shop floor experience into the book which I have titled “Textile Dyes.”
Each chapter is simplified into the major class of dyes. I have dealt with the history, manufacturing, properties, identification, stripping, testing and application of dyes.
It is written in a very simple language and in a lucid manner. The book will be helpful to textile students, research students, supervisors working in the dyes and textile industries.
For the last 2 years, the prices of H Acid were so high that the prices of Reactive Dyes went skyrocketing. Every person in the industry was worried for H Acid. I found that time everybody came to know about H Acid. How crucial raw material or dye intermediate it was for the dyes industry. But they didn’t know the role of H Acid in manufacturing of reactive dyes. This book deals about the manufacturing process.
This will be helpful both to the dyes industry as well as textile industry.
N. N. Mahapatra