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An Investigation into the
Development of Environmentally
Friendly Pigment Colouration
A thesis submitted to the University of Manchester for the degree of
Doctor of Philosophy (PhD)
in the Faculty of Engineering and Physical Sciences
2013
Qingqing Cao
School of Materials
Contents
1
Contents
Contents 1
List of Figures 6
List of Tables 13
Glossary of Terms 16
Abstract 17
Declaration 18
Copyright Statement 19
Acknowledgements 20
Chapter 1 Textile Colouration 21
1.1 Definition 21
1.2 History 21
1.3 Classification 23
1.3.1 Textile printing 23
1.3.2 Textile dyeing 24
1.4 Textile colouration of cotton 25
1.4.1 Cotton fibres 25
1.4.2 Colourants for cotton 27
1.5 Textile colouration for polyester 30
1.5.1 Polyester 30
1.5.1.1 Poly (ethylene terephthalate) Fibres 32
1.5.1.2 Poly (lactic acid) Fibres 32
1.5.2 Dyeing polyester 33
1.6 Machinery 34
1.6.1 Dyeing machinery 34
1.6.1.1 Dyeing in the loose fibre form 35
1.6.1.2 Dyeing yarn 35
1.6.1.3 Dyeing fabrics 36
1.6.1.4 Continuous dyeing equipment 39
1.6.2 Printing machinery 40
1.7 References 42
Contents
2
Chapter 2 Pigment Colouration 46
2.1 Definition and overview 46
2.2 History 46
2.3 Pigments 47
2.3.1 Definition 47
2.3.2 History 47
2.3.3 Dyes and pigments 48
2.3.4 Classification of pigments 50
2.3.4.1 Organic pigments 50
2.3.4.2 Water-soluble dyes 54
2.3.4.3 Inorganic pigments 54
2.4 Binder system 55
2.5 Softeners 56
2.6 Other Auxiliaries 58
2.7 Pigment Application System 60
2.7.1 Print System 60
2.7.2 Padding System 60
2.7.3 Exhaust Dyeing System 61
2.7.4 Modification of Pigment Application System 61
2.7.4.1 Cationization 61
2.7.4.2 Plasma Treatment 62
2.7.4.3 Fluorocarbon Treatment of dyed fabrics 64
2.8 Advantages and Disadvantages of Pigment Colouration 66
2.9 Aims and Objectives of Research 67
2.10 References 68
Chapter 3 Instrumental Techniques 73
3.1 Introduction 73
3.2 Physical Testing 73
3.2.1 Colour fastness 73
3.2.1.1 Rub fastness 74
3.2.1.2 Wash fastness 75
3.2.2 Colour Strength 76
3.2.3 Martindale Abrasion Test 77
3.2.4 KES-F System 77
3.2.5 Oil and Water Repellency Measurements 80
3.3 Analytical Methods 82
3.3.1 Scanning Electron Microscopy (SEM) 82
Contents
3
3.3.2 X-ray Photoelectron Spectroscopy (XPS) 83
3.3.3 Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) 84
3.4 References 85
Chapter 4 Investigation of Basic Binder System 87
4.1 Introduction 87
4.2 Experimental 88
4.2.1 Materials 88
4.2.2 Dyeing System 89
4.2.3 Matrix OSD System 89
4.2.4 Modified Matrix OSD System 90
4.2.5 Matrix OSD without Softener 90
4.3 Results and Discussion 91
4.3.1 Matrix OSD System 91
4.3.2 Modified Matrix OSD System 94
4.3.2.1 Treatment on Cotton 94
4.3.2.2 Treatment on PET and Polycotton 106
4.3.3 Effect of Curing Time on the Performance of the Matrix OSD System 107
4.3.4 Performance of Matrix OSD without Softener System 109
4.4 Conclusions 112
4.5 References 113
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and
Surface Modification on the Performance of Matrix OSD Treatments 115
5.1 Introduction 115
5.2 Experimental Work 117
5.2.1 Materials 117
5.2.2 Pigment Dyeing System 117
5.2.3 Fabric Pretreatment by Cationic Fixing Agent 117
5.2.4 Crosslinker Treatment 118
5.2.5 UVO treatment 119
5.3 Results and Discussion 120
5.3.1 Effect of Cationization Treatment 120
5.3.2 Effect of Crosslinkers 122
5.3.2.1 Effect of Nanolink 122
5.3.2.2 Effect of Citric Acid 123
5.3.2.3 Effect of Knittex MLF New 126
5.3.2.4 Effect of Citric Acid and Knittex MLF New 128
5.3.2.5 Effect of DMDHEU Pre-Treatment 131
5.3.3 Effect of UVO Treatment 132
Contents
4
5.4 Conclusions 139
5.5 References 140
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix
OSD Treated Fabric Performance 141
6.1 Introduction 141
6.2 Experimental Work 142
6.2.1 Materials 142
6.2.2 Dyeing System 142
6.2.3 Fluorocarbon Treatment 143
6.2.3.1 Scotchguard FC3548 143
6.2.3.2 Shield F-01 with Shield Extender FCD 143
6.2.3.3 Shield FRN6 144
6.2.3.4 P2i 144
6.2.3.5 Oleophobol 7713 with Hydrophobol XAN 144
6.2.3.6 Rucoguard LAD and Oleophobol 7713 145
6.3 Results and Discussion 146
6.3.1 Effect of Scotchguard FC3548 146
6.3.2 Shield F-01 with Shield extender FCD 154
6.3.2.1 Treatments on Cotton 154
6.3.2.2 Fluorocarbon Treatments on Polycotton Fabric 159
6.3.3 Shield FRN6 161
6.3.4 Effect of P2i dry plasma polymerisation treatments on pigment dyed
fabric fastness and liquid repellency performance 169
6.3.5 Effect of Oleophobol on repellency performance 175
6.3.6 Water/Oil Repellency Performance 178
6.3.6.1 Fluorocarbon Application to Undyed Cotton Fabric 178
6.3.6.2 Matrix OSD System with No Softener 179
6.3.6.3 Rucoguard LAD and Oleophobol 7713 180
6.4 Conclusions 181
6.5 References 182
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD
Treated Cotton Fabric 183
7.1 Introduction 183
7.2 Experimental work 184
7.2.1 Materials 184
7.2.2 Dyeing System 184
7.2.3 Plasma Treatment 184
7.2.3.1 Plasma pre-treatment 184
Contents
5
7.2.3.2 Plasma after-treatment 185
7.3 Results and Discussion 185
7.3.1 Effect of Pre-treatment 185
7.3.2 Effect of Plasma After- treatment on the Fastness of Pigment Dyed
Fabrics 187
7.4 Conclusions 194
7.5 References 195
Chapter 8 Surface Analysis 197
8.1 XPS Analysis of Blue Pigment-dyed Cotton Treated with Fluorocarbons 197
8.2 ToF-SIMS Analysis of Blue Pigment-dyed Cotton Treated with Fluorocarbon
Finishes 211
8.2.1 ECE Detergent with Phosphates 211
8.2.2 Matrix OSD Binder Applied to Cotton Fabric 214
8.2.3 P2i Process 3 Treatment 222
8.2.4 FRN6 Treatment 230
8.2.5 F-01 Treatment 237
8.3 Conclusions 244
8.4 References 245
Chapter 9 Conclusions and Future Work 246
9.1 Summary and Conclusions 246
9.2 Future Work 250
Counted words: 45,037
List of Figures
6
List of Figures
Figure 1.1 Scanning electron micrograph of cotton fibres 26
Figure 1.2 Morphology of the cotton fibre [17] 26
Figure 1.3 Cellulose polymer 27
Figure 1.4 Chemical synthesis of PET 32
Figure 1.5 Winch dyeing machine 37
Figure 1.6 Jig dyeing machine 37
Figure 1.7 Beam dyeing machine 38
Figure 1.8 Jet dyeing machine 39
Figure 1.9 Continuous dyeing equipment 40
Figure 2.1 CI Pigment Red 1 Para Red 51
Figure 2.2 Copper phthalocyanine 52
Figure 2.3 CI Pigment Violet 19 53
Figure 2.4 Brilliant sulfoflavine FF (yellow) 53
Figure 3.1 AATCC crockmeter 74
Figure 3.2 Grey scale assessment for staining 75
Figure 3.3 Grey scale for assessing colour change 76
Figure 3.4 Schematic of a typical SEM 83
Figure 4.1 Effect of varying the concentration of the formulation applied to cotton
fabric on the KES-F bending stiffness, B 93
Figure 4.4 Effect of varying the concentration of the formulation applied to cotton
fabric on the KES-F bending stiffness, B 97
Figure 4.5 Effect of varying the concentration of the formulation applied to cotton
fabric on the KES-F shear stiffness, G 98
Figure 4.6 Effect of varying the concentration of the formulation applied to cotton
fabric on shear hysteresis at 5o, 2HG5 98
Figure 4.7 SEM micrographs of untreated cotton 99
Figure 4.8 SEM micrographs of 9 g/L binder covered cotton 99
Figure 4.9 SEM micrographs of 90g/L binder covered cotton 100
Figure 4.10 SEM micrographs of 135 g/L binder covered cotton 100
Figure 4.11 SEM micrographs of yellow dyed cotton at a stock formulation
concentration of 10g/L 101
Figure 4.12 SEM micrographs of yellow dyed cotton at a stock formulation
concentration of 100 g/L 101
Figure 4.13 SEM micrographs of yellow dyed cotton at a stock formulation
concentration of 150g/L 102
Figure 4.14 SEM micrographs of red dyed cotton at a stock formulation concentration
of 10g/L 102
Figure 4.15 SEM micrographs of red dyed cotton at a stock formulation concentration
List of Figures
7
of 100g/L 103
Figure 4.16 SEM micrographs of red dyed cotton at a stock formulation concentration
of 150g/L 103
Figure 4.17 SEM images of blue dyed cotton at stock formulation conc.10g/L 104
Figure 4.18 SEM micrographs of blue dyed cotton at a stock formulation
concentration of 100g/L 104
Figure 4.19 SEM micrographs of blue dyed cotton at a stock formulation
concentration 150g/L 105
Figure 4.20 SEM micrographs of abraded red dyed cotton 105
Figure 4.21 Effect of softener incorporated into binder system on the bending stiffness,
B, of pigment dyed cotton fabric 111
Figure 4.22 Effect of softener incorporated into binder system on the shear stiffness,
G, of pigment dyed cotton fabric 111
Figure 4.23 Effect of softener incorporated into binder system on the shear hysteresis
at 5o, 2HG5, of pigment dyed cotton fabric 112
Figure 5.1 Effect of varying the cationic fixing agent concentration on the colour
strength of pigment dyed cotton fabric 122
Figure 5.2 Effect of UVO exposure on the colour strength of pigment dyed cotton
fabric 134
Figure 5.3 SEM micrographs of 5 minutes-UVO treated red dyed cotton at 10g/L
stock formulation concentration 135
Figure 5.4 SEM micrographs of 10 minutes-UVO treated red dyed cotton at 10g/L
stock formulation concentration 135
Figure 5.5 SEM micrographs of 15 minutes-UVO treated red dyed cotton at 10g/L
stock formulation concentration 136
Figure 5.6 SEM micrographs of 5 minutes-UVO treated red dyed cotton at 100g/L
stock formulation concentration 136
Figure 5.7 SEM micrographs of 10 minutes-UVO treated red dyed cotton at 100g/L
stock formulation concentration 137
Figure 5.8 SEM micrographs of 15 minutes-UVO treated red dyed cotton at 100g/L
stock formulation concentration 137
Figure 5.9 SEM micrographs of 5 minutes-UVO treated red dyed cotton at 150g/L
stock formulation concentration 138
Figure 5.10 SEM micrographs of 10 minutes-UVO treated red dyed cotton at 150g/L
stock formulation concentration 138
Figure 5.11 SEM micrographs of 15 minutes-UVO treated red dyed cotton at 150g/L
stock formulation concentration 139
Figure 6.1 Effect of varying FC3548 concentration on the colour strength of
increasing concentrations of pigment formulation applied to cotton fabric 150
Figure 6.2 Effect of varying FC3548 concentration on the colour strength of pigment
dyed cotton fabrics 150
Figure 6.3 SEM micrographs of 5g/L FC3548 treated red-dyed cotton at a stock
List of Figures
8
formulation concentration of 10g/L 151
Figure 6.4 SEM micrographs of 10g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 10g/L 151
Figure 6.5 SEM micrographs of 30g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 10g/L 151
Figure 6.6 SEM micrographs of 50g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 10g/L 151
Figure 6.7 SEM micrographs of 5g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 100g/L 152
Figure 6.8 SEM micrographs of 10g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 100g/L 152
Figure 6.9 SEM micrographs of 30g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 100g/L 152
Figure 6.10 SEM micrographs of 50g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 100g/L 152
Figure 6.11 SEM micrographs of 5g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 150g/L 153
Figure 6.12 SEM micrographs of 10g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 150g/L 153
Figure 6.13 SEM micrographs of 30g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 150g/L 153
Figure 6.14 SEM micrographs of 50g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 150g/L 153
Figure 6.15 Effect of varying F-01 concentration on the colour strength of pigment
dyed cotton fabrics 156
Figure 6.16 SEM micrographs of 20g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 10g/L 157
Figure 6.17 SEM micrographs of 40g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 10g/L 157
Figure 6.18 SEM micrographs of 60g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 10g/L 157
Figure 6.19 SEM micrographs of 20g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 100g/L 157
Figure 6.20 SEM micrographs of 40g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 100g/L 158
Figure 6.21 SEM micrographs of 60g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 100g/L 158
Figure 6.22 SEM micrographs of 20g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 150g/L 158
Figure 6.23 SEM micrographs of 40g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 150g/L 158
Figure 6.24 SEM micrographs of 60g/L F-01 treated red-dyed cotton at a stock
List of Figures
9
formulation concentration of 150g/L 159
Figure 6.25 Effect of varying F-01 concentration on the colour strength of pigment
dyed polycotton fabrics 161
Figure 6.26 Effect of varying FRN6 concentration on the colour strength of pigment
dyed cotton fabric 165
Figure 6.27 Effect of varying FRN6 concentration on the bending stiffness of red
pigment dyed cotton fabric 165
Figure 6.28 Effect of varying FRN6 concentration on the shear stiffness of red
pigment dyed cotton fabric 166
Figure 6.29 Effect of varying FRN6 concentration on the shear hysteresis, 2HG5, of
red pigment dyed cotton fabric 166
Figure 6.30 SEM micrographs of 30g/L F6 treated red-dyed cotton at a stock
formulation concentration of 10g/L 167
Figure 6.31 SEM micrographs of 45g/L F6 treated red-dyed cotton at a stock
formulation concentration of 10g/L 167
Figure 6.32 SEM micrographs of 60g/L F6 treated red-dyed cotton at a stock
formulation concentration of 10g/L 167
Figure 6.33 SEM micrographs of 30g/L F6 treated red-dyed cotton at a stock
formulation concentration of 100g/L 167
Figure 6.34 SEM micrographs of 45g/L F6 treated red-dyed cotton at a stock
formulation concentration of 100g/L 168
Figure 6.35 SEM micrographs of 60g/L F6 treated red-dyed cotton at a stock
formulation concentration of 100g/L 168
Figure 6.36 SEM micrographs of 30g/L F6 treated red-dyed cotton at a stock
formulation concentration of 150g/L 168
Figure 6.37 SEM micrographs of 45g/L F6 treated red-dyed cotton at a stock
formulation concentration of 150g/L 168
Figure 6.38 SEM micrographs of 60g/L F6 treated red-dyed cotton at a stock
formulation concentration of 150g/L 169
Figure 6.39 Effect of varying P2i treatment on the colour strength of blue pigment
dyed cotton fabric 171
Figure 6.40 Effect of varying P2i treatment on the bending stiffness blue pigment
dyed cotton fabric 172
Figure 6.41 Effect of varying P2i treatment on the shear stiffness of blue pigment
dyed cotton fabric 172
Figure 6.42 Effect of varying P2i treatment on the shear hysteresis, 2HG5, of blue
pigment dyed cotton fabric 173
Figure 6.43 SEM micrographs of P2i process 1 treated blue-dyed cotton at a stock
formulation concentration of 10g/L 173
Figure 6.44 SEM micrographs of P2i process 2 treated blue-dyed cotton at a stock
formulation concentration of 10g/L 173
Figure 6.45 SEM micrographs of P2i process 3 treated blue-dyed cotton at a stock
List of Figures
10
formulation concentration 10g/L 174
Figure 6.46 SEM micrographs of P2i process 1 treated blue-dyed cotton at a stock
formulation concentration of 100g/L 174
Figure 6.47 SEM micrographs of P2i process 2 treated blue-dyed cotton at a stock
formulation concentration of 100g/L 174
Figure 6.48 SEM micrographs of P2i process 3 treated blue-dyed cotton at a stock
formulation concentration of 100g/L 174
Figure 6.49 SEM micrographs of P2i process 1 treated blue-dyed cotton at a stock
formulation concentration of 150g/L 175
Figure 6.50 SEM micrographs of P2i process 2 treated blue-dyed cotton at a stock
formulation concentration of 150g/L 175
Figure 6.51 SEM micrographs of P2i process 3 treated blue-dyed cotton at a stock
formulation concentration of 150g/L 175
Figure 6.52 Effect of varying Oleophobol concentration on the colour strength of blue
pigment dyed cotton fabric (λmax=610nm) 177
Figure 7.1 Effect of plasma pre-treatment on colour strength (λmax=610nm) 187
Figure 8.1 C (1s) XP spectrum of untreated cotton fabric 200
Figure 8.2 C (1s) XP spectrum of 10g/L blue dyed cotton fabric 200
Figure 8.3 C (1s) XP spectrum of 100g/L blue dyed cotton fabric 200
Figure 8.4 C (1s) XP spectrum of 150g/L blue dyed cotton fabric 201
Figure 8.5 C (1s) XP spectrum of 10g/L blue dyed cotton fabric treated with 40g/L
F-01 201
Figure 8.6 C (1s) XP spectrum of 100g/L blue dyed cotton fabric treated with 40g/L
F-01 201
Figure 8.7 C (1s) XP spectrum of 150g/L blue dyed cotton fabric treated with 40g/L
F-01 202
Figure 8.8 C (1s) XP spectrum of 10g/L blue dyed cotton fabric treated with 60g/L
F-01 202
Figure 8.9 C (1s) XP spectrum of 100g/L blue dyed cotton fabric treated with 60g/L
F-01 202
Figure 8.10 C (1s) XP spectrum of 150g/L blue dyed cotton fabric treated with 60g/L
F-01 203
Figure 8.11 C (1s) XP spectrum of washed 150g/L blue dyed cotton fabric treated with
60g/L F-01 203
Figure 8.12 C (1s) XP spectrum of washed & heat pressed 150g/L blue dyed cotton
fabric treated with 60g/L F-01 203
Figure 8.13 C (1s) XP spectrum of 10g/L blue dyed cotton fabric treated with 45g/L
FRN6 204
Figure 8.14 C (1s) XP spectrum of 100g/L blue dyed cotton fabric treated with 45g/L
FRN6 204
Figure 8.15 C (1s) XP spectrum of 150g/L blue dyed cotton fabric treated with 45g/L
FRN6 204
List of Figures
11
Figure 8.16 C (1s) XP spectrum of 10g/L blue dyed cotton fabric treated with 60g/L
FRN6 205
Figure 8.17 C (1s) XP spectrum of 100g/L blue dyed cotton fabric treated with 60g/L
FRN6 205
Figure 8.18 C (1s) XP spectrum of 150g/L blue dyed cotton fabric treated with 60g/L
FRN6 205
Figure 8.19 C (1s) XP spectrum of washed 150g/L blue dyed cotton fabric treated with
60g/L FRN6 206
Figure 8.20 C (1s) XP spectrum of washed & heat pressed 150g/L blue dyed cotton
fabric treated with 60g/L FRN6 206
Figure 8.21 C (1s) XP spectrum of 10 g/L blue dyed cotton treated with P2i Process 1
207
Figure 8.22 C (1s) XP spectrum of 100g/L blue dyed cotton treated with P2i Process 1
207
Figure 8.23 C (1s) XP spectrum of 150g/L blue dyed cotton treated with P2i Process 1
208
Figure 8.24 C (1s) XP spectrum of 10 g/L blue dyed cotton treated with P2i Process 2
208
Figure 8.25 C (1s) XP spectrum of 100g/L blue dyed cotton treated with P2i Process 2
208
Figure 8.26 C (1s) XP spectrum of 150g/L blue dyed cotton treated with P2i Process 2
209
Figure 8.27 C (1s) XP spectrum of 10 g/L blue dyed cotton treated with P2i Process 3
209
Figure 8.28 C (1s) XP spectrum of 100g/L blue dyed cotton treated with P2i Process 3
209
Figure 8.29 C (1s) XP spectrum of 150g/L blue dyed cotton treated with P2i Process 3
210
Figure 8.30 C (1s) XP spectrum of washed 150g/L blue dyed cotton treated with P2i
Process 3 210
Figure 8.31 C (1s) XP spectrum of washed & heat pressed 150g/L blue dyed cotton
treated with P2i Process 3 210
Figure 8.32 Typical composition of the linear alkyl benzene sulphonates (LAS) 211
Figure 8.33 (a)-(d) ToF-SIMS positive ion spectra of ECE detergent powder 213
Figure 8.34 (a)-(c) ToF-SIMS negative ion spectra of ECE detergent powder 214
Figure 8.35 Cellulose-specific 214
Figure 8.36 ToF-SIMS spectra of untreated cotton fabric 215
Figure 8.37 (a)-(e) ToF-SIMS positive ion spectra of Matrix OSD binder applied to
cotton fabric 218
Figure 8.38 (a)-(c) ToF-SIMS negative ion spectra of Matrix OSD binder applied to
cotton fabric 219
Figure 8.39 The intensity of the more hydrophobic LAS 220
List of Figures
12
Figure 8.40 (a)-(e) ToF-SIMS positive ion spectra of ISO CO6 washed cotton fabric
with applied Matrix OSD Binder 221
Figure 8.41 (a)-(c) ToF-SIMS negative ion spectra of ISO CO6 washed cotton fabric
with applied Matrix OSD Binder 222
Figure 8.42 (a)-(c) ToF-SIMS positive ion spectra of P2i Process 3 treated cotton
fabric with applied Matrix OSD 225
Figure 8.43 (a)-(c) ToF-SIMS negative ion spectra of P2i Process 3 treated cotton
fabric with applied Matrix OSD 226
Figure 8.44 (a)-(e) ToF-SIMS positive ion spectra of ISO CO6 washed P2i Process 3
treated cotton fabric with applied Matrix OSD 227
Figure 8.45 (a)-(c) ToF-SIMS negative ion spectra of ISO CO6 washed P2i Process 3
treated cotton fabric with applied Matrix OSD 228
Figure 8.46 (a)-(c) ToF-SIMS positive ion spectra of washed and heat pressed P2i
Process 3 treated cotton fabric with applied Matrix OSD 229
Figure 8.47 (a)-(c) ToF-SIMS negative ion spectra of washed and heat pressed P2i
Process 3 treated cotton fabric with applied Matrix OSD 230
Figure 8.48 (a)-(d) ToF-SIMS positive spectra of 60g/L FRN6 treated cotton fabric
with applied Matrix OSD 232
Figure 8.49 (a)-(c) ToF-SIMS negative spectra of 60g/L FRN6 treated cotton fabric
with applied Matrix OSD 233
Figure 8.50 (a)-(c) ToF-SIMS positive ion spectra of ISO CO6 washed 60g/L FRN6
treated cotton fabric with applied Matrix OSD 234
Figure 8.51 (a)-(c) ToF-SIMS negative ion spectra of ISO CO6 washed 60g/L FRN6
treated cotton fabric with applied Matrix OSD 235
Figure 8.52 (a)-(c) ToF-SIMS positive ion spectra of washed & heat pressed 60g/L
FRN6 treated cotton fabric with applied Matrix OSD 236
Figure 8.53 (a)-(c) ToF-SIMS negative ion spectra of washed & heat pressed 60g/L
FRN6 treated cotton fabric with applied Matrix OSD 237
Figure 8.54 (a)-(c) ToF-SIMS positive spectra of 60g/L F-01 treated cotton fabric with
applied Matrix OSD 239
Figure 8.55 (a)-(c) ToF-SIMS spectra of 60g/L F-01 treated cotton fabric with applied
Matrix OSD 240
Figure 8.56 (a)-(c) ToF-SIMS positive ion spectra of ISO CO6 washed 60g/L F-01
treated cotton fabric with applied Matrix OSD 241
Figure 8.57 (a)-(c) ToF-SIMS negative ion spectra of ISO CO6 washed 60g/L F-01
treated cotton fabric with applied Matrix OSD 242
Figure 8.58 (a)-(c) ToF-SIMS positive ion spectra of washed & heat pressed 60g/L
F-01 treated cotton fabric with applied Matrix OSD 243
Figure 8.59 (a)-(c) ToF-SIMS negative ion spectra of washed & heat pressed 60g/L
F-01 treated cotton fabric with applied Matrix OSD 244
List of Tables
13
List of Tables
Table 1.1 Physical & chemical properties of polyester fibres 31
Table 2.1 A comparison of the general characteristics of dyes and pigments 49
Table 3.1 Test intervals for abrasion testing 77
Table 3.2 Parameters measured in the Kawabata Evaluation System 79
Table 3.3 Range of test liquids with decreasing surface tension for the oil-repellency
test 81
Table 3.4 Range of test liquids employed with decreasing surface tension 81
Table 4.1 Concentration of stock formulations 90
Table 4.2 Concentration of stock formulation 90
Table 4.3 Effect of varying the concentration of the formulation applied to cotton
fabric on the wet/dry rub fastness 92
Table 4.4 Effect of varying the concentration of the formulation applied to cotton
fabric on the colour strength 92
Table 4.5 Effect of varying the concentration of the formulation applied to cotton
fabric on the rub and wash fastness 96
Table 4.6 Effect of varying the concentration of the formulation applied to cotton
fabric on the colour strength 96
Table 4.7 Effect of varying the concentration of the formulation applied to cotton
fabric on the Martindale flat abrasion 97
Table 4.8 Effect of varying the concentration of the pigment formulation applied to
cotton, PET and polycotton fabrics on the fastness 106
Table 4.9 Effect of varying the concentration of the pigment formulation applied to
cotton, PET and polycotton fabrics on the colour strength 106
Table 4.10 Effect of different curing times on the fastness of yellow pigment dyed
cotton fabric 107
Table 4.11 Effect of different curing times on the fastness of red pigment dyed cotton
fabric 108
Table 4.12 Effect of different curing times on the fastness of blue pigment dyed cotton
fabric 109
Table 4.13 Effect of varying concentration of formulation applied to cotton fabric on
rub and wash fastness 110
Table 4.14 Effect of varying concentration of formulation applied to cotton fabric on
colour strength 110
Table 5.1 Effect of varying the cationic fixing agent concentration on the fastness of
pigment dyed cotton fabric 121
Table 5.2 Effect of 2% o.w.f. application of Nanolink on the fastness properties of of
pigment dyed cotton fabric 123
Table 5.3 Effect of citric acid pre-treatment of cotton on the fastness of the yellow
pigment dyed fabric 124
List of Tables
14
Table 5.4 Effect of citric acid pre-treatment of cotton on the fastness of the red
pigment dyed fabric 125
Table 5.5 Effect of citric acid pre-treatment of cotton on the fastness of the blue
pigment dyed fabric 126
Table 5.6 Effect of the application of Knittex MLF New pre-treatment to cotton on the
fastness of pigment dyed fabric 127
Table 5.7 Effect of incorporating Knittex MLF New into the pigment dyeing
formulation applied to cotton fabric on colour fastness 128
Table 5.8 Effect of pre-treatment with citric acid and Knittex MLF New on the
fastness performance of yellow pigment dyed cotton fabric 129
Table 5.9 Effect of pre-treatment with citric acid and Knittex MLF New on the
fastness performance of red pigment dyed cotton fabric 130
Table 5.10 Effect of pre-treatment with citric acid and Knittex MLF New on the
fastness performance of blue pigment dyed cotton fabric 131
Table 5.11 Effect of 100g/L DMDHEU pre-treatment on the fastness performance of
pigment dyed cotton fabric 132
Table 5.12 Effect of UVO treatment on the fastness performance of pigment dyed
cotton fabric 133
Table 6.1 Concentration of Shield F-01aftertreating system 144
Table 6.2 Effect of varying FC3548 concentration within the pigment dyeing
formulation on the fastness of coloured cotton fabric 148
Table 6.3 Effect of varying FC3548 concentration on the fastness performance of red
pigment dyed cotton fabric 149
Table 6.4 Effect of FC3548 concentration on the Martindale Flat Abrasion
performance of pigment dyed cotton fabrics 149
Table 6.5 Effect of varying F-01 concentration on the fastness of pigment dyed cotton
fabrics 155
Table 6.6 Effect of varying F-01 concentration on the water and oil repellency of
pigment dyed cotton fabrics 156
Table 6.7 Effect of varying F-01 concentration on the fastness of pigment dyed
polycotton fabrics 160
Table 6.8 Effect of varying FRN6 concentration on the fastness performance of
pigment dyed cotton fabric 163
Table 6.9 Effect of varying FRN6 concentration on the flat abrasion of pigment dyed
cotton fabric 164
Table 6.10 Effect of varying FRN6 concentration on the water and oil repellency of
red pigment dyed cotton fabric 164
Table 6.11 Effect of varying P2i treatment on the fastness of blue pigment dyed cotton
fabric 170
Table 6.12 Effect of varying P2i treatment on the water and oil repellency of blue
pigment dyed cotton fabric 171
Table 6.13 Effect of varying Oleophobol concentration on the fastness of blue
List of Tables
15
pigment dyed cotton fabric 176
Table 6.14 Effect of varying Oleophobol concentration on the water and oil repellency
of blue pigment dyed cotton fabric 177
Table 6.15 Water and oil repellency of cotton fabric treated with fluorocarbons and
subsequently washed and heat pressed 178
Table 6.16 Abrasion resistance on cotton fabric treated by fluorocarbons 179
Table 6.17 Water and oil repellency of red pigment dyed cotton treated with F-01 and
FRN6 fluorocarbon finishes 180
Table 6.18 Water and oil repellency of plain untreated cotton and red pigment dyed
cotton treated by Rucoguard LAD and Oleophobol 7713 by exhaustion and padding
applications 181
Table 7.1 Plasma treatment conditions 185
Table 7.2 Effect of plasma pre-treatment on colour fastness 186
Table 7.3 Effect of plasma after-treatment on heat cured yellow pigment dyed fabric
fastness 189
Table 7.4 Effect of plasma after-treatment on heat cured red pigment dyed fabric
fastness 190
Table 7.5 Effect of plasma after-treatment on heat cured blue pigment dyed fabric
fastness 191
Table 7.6 Effect of plasma after-treatment on uncured yellow pigment dyed fabric,
followed by heat curing, fastness 192
Table 7.7 Effect of plasma after-treatment on uncured red pigment dyed fabric,
followed by heat curing, fastness 193
Table 7.8 Effect of plasma after-treatment on uncured blue pigment dyed fabric,
followed by heat curing, fastness 194
Table 8.1 XPS surface elemental composition of blue pigment dyed cotton fabric
treated with fluorocarbons 199
Table 8.2 ToF-SIMS Fatty alcohol ethoxylates ion assignments 212
Table 8.3 Polyacrylate positive ion assignments 216
Table 8.4 Poly(acrylate) negative ion assignments 217
Table 8.5 PDMS (-[(CH3)2SiO]n-) ion assignments 217
Table 8.6 Positive fluorocarbon species 224
Table 8.7 Negative fluorocarbon species 224
Glossary of Terms
16
Glossary of Terms
Polyethylene terephthalate PET
Polylactic acid PLA
Kawabata Evaluation System KES
Scanning Electron Microscopy SEM
X-ray Photoelectron Spectroscopy XPS
Time-of-Flight Secondary Ion Mass Spectrometry ToF-SIMS
Dimethylol Dihydroxy Ethylene Urea DMDHEU
Ultraviolet/ozone UVO
Abstract
17
Abstract
University of Manchester
Qingqing Cao
Doctor of Philosophy (PhD)
An investigation of environmentally friendly pigment colouration
12th
, February 2013
This research has investigated the modification of cotton fabric and pigment dyeing
system in order to improve the colouration properties, such as rub fastness, wash
fastness, colour strength and fabric handle of the textile material. It involved four
different approaches based on pre-cationization of the fabric, incorporation of
crosslinkers into the binder formulation, UVO pre-treatment of the fabric, and wet
fluorocarbon treatment and dry plasma polymerisation treatments.
It has been reported that the Matrix OSD pigment dyeing system offers benefits in
terms of processing cost and environmental impact and from the initial studies it was
apparent that while dry rub fastness, mechanical rigidity and washing performance
were generally acceptable the wet rub fastness of the printed fabrics presented a
technical challenge. Therefore in this study the colour wet rub fastness was regarded
as the main performance indicator to be targeted and improved. Cationizing the
cotton fabrics prior to pigment dyeing improved the wet rub fastness performance of
the Matrix OSD dyeing system, while the other fastness properties were in general
unchanged. Similarly crosslinking treatments enhanced the colour fastness
performance, due to the improvement of the bonding between the binder and fabrics.
The crosslinking/crease resist pre-treatment offers better performance than the
combined application method in terms of improving the wet rub fastness. Surface
modification of textile materials is able to modify the textile wettability, adhesion,
dyeability and handle and therefore has been studied with a view to improving the
durability of the surface pigment dyed coating. However in this study the benefits of
a UV/Ozone (UVO) pre-treatment previously observed for other long liquor fabric
dyeing studies of textiles was not observed and it was established that the pigment
dyeing performance was reduced after the sensitised photo-oxidation treatment. The
investigation demonstrated that the fluorocarbon treatments had a beneficial effect
on colour wash fastness and wet rub fastness, while dry rub fastness was marginally
reduced at higher fluorocarbon application levels. Different fluorocarbons were
examined in this study, and the aftertreatment with Shield F-01 and Shield extender
FCD offered the best results. A range of plasma pre-treatments prior to pigment
dyeing were also examined but only a marginal benefit on the colour fastness
properties and to some extent slightly decreased dry rub fastness was observed. In
contrast the plasma after-treatments, using both argon (Ar) and nitrogen (N2)
atmospheres, improved the fastness, particularly wet fastness, particularly when the
binder heat curing process was before plasma after-treatment.
Declaration
18
Declaration
No portion of this work has been submitted in support of any application for another
degree or qualification of this or any other University or other institution of learning.
Qingqing Cao
Copyright Statement
19
Copyright Statement
Copyright in text of this thesis rests with the Author. Copies (by any process)
either in full, or of extracts, may be made only in accordance with instructions
given by the Author and lodged in the John Rylands University Library of
Manchester. Details may be obtained from the librarian. This page must form part
of any such copies made. Further copies (by any process) of copies made in
accordance with such instructions may not be made without the permission (in
writing) of the Author.
The ownership of any intellectual property rights which may be described in this
thesis is vested in the University of Manchester, subject to any prior agreement to
the contrary, and may not be made available for use by third parties without the
written permission of the University, which will prescribe the terms and
conditions of any such agreement.
Further information on the conditions under which disclosures and exploitation
may take place is available from the Head of School of Materials.
Acknowledgements
20
Acknowledgements
I would like to thank my supervisors Professor C. M. Carr and Dr M. Rigout for
their valuable advice, guidance and encouragement during my study.
I am very grateful to the support of Mr. Phil Cohen and Mr. David Kenyon for their
really helpful suggestions and patience. I would also thank Ms Xiangli Zhong for
her excellent SEM training session and suggestions in the SEM analysis. I would
like give special thanks to Ms Alison Harvey for the KES handle properties and XPS
studies which required great patience.
I would like to thank my parents. I would give my greatest gratitude for my mother’s
support, encouragement and love. I would thank all my friends in Manchester for all
those lovely memories.
Chapter 1 Textile Colouration
21
Chapter 1 Textile Colouration
1.1 Definition
Textile colouration mainly involves textile printing, textile dyeing and mass
pigmentation of synthetic filaments during melt spinning [1]. Dyeing and printing of
textile materials typically relies on the transfer of dye chromophoric molecules from
the application medium, such as aqueous dye solutions or print pastes, and diffusion
of the colourant into the fibres [1, 2]. In contrast pigments can be bound to the fabric
structure by a polymeric binder, in pigment print or dyeing, or incorporated inside
the filament during mass pigmentation.
Textile printing is a process to pattern a fabric by applying colourant (dyes or
pigments) and other auxiliary chemicals, usually in a repeated structure [3]. Textile
dyeing, unlike textile printing, refers to the colouration of the entire fabric, while
printing is just a particular area patterning and normally a one-sided effect. Dyeing
can be described as the process of applying a comparatively permanent colour to
fibre, yarn or fabric by immersing in a bath of dye [4]. Dyeing is double-side
coloured while printing is usually one-side coloured.
1.2 History
The textile industry is considered as one of the largest global industries, and if all
aspects of the diverse textile supply chain are taken into account, it is recognised that
the textile industry involves more people and more assets than most other
manufacturing industries. At the same time, the textile industry is also one of the
oldest industries [5]. Archaeological evidence indicates that fine quality textiles were
produced thousands of years ago, long before the oldest preserved written documents
first mentioned them. The ancient history of textile fibres and fabrics has been shown
Chapter 1 Textile Colouration
22
by such archaeological discoveries as spinning whorls, distaffs, loom weights, and
fragments of fabrics found in the Swiss lake regions and Egyptian tombs [5].
As an integral part of the textile aesthetics and functionality, colouration is as old as
textiles themselves. The origins of textile dyeing are uncertain, but some coloured
fabrics which were dyed yellow, a colour obtained from the safflower plant, were
discovered in ancient Egyptian tombs from about 3500 BC [2, 6]. Until 1856, all dyes
were made from natural materials, mainly animal and vegetable sources, with a few
minerals being used for special colours. Then in 1856 Sir William Henry Perkin, when
trying to create artificial quinine from coal tar, happened to produce the first synthetic
dyestuff, a purple basic dye, mauveine. Nowadays almost all commercial dyes are
manufactured synthetically with the synthetic derivatives being superior in most
performance aspects when compared to natural dyes [5].
It is likely that the ancient dyeing originated from India [2, 6] where at that time,
soaking fabric in aqueous natural colourant plant extracts was the primary dyeing
method. Consequently, the range of colours was limited, the hue was dull and the
products invariably had poor wash fastness and light fastness [7]. In the
mid-seventeenth century, because of the development of systematic quality control in
the French dyeing industry, textile dyeing gained a new momentum which during the
eighteenth and early nineteenth centuries provided a greater understanding and
associated scientific methodology. This new enlightened and better informed
approach has continued with general advancements in the broader scientific field [8].
As an important component of overall garment appearance, the influence and
development of textile printing has played a critical role in the history of clothes and
their aesthetics. In ancient times, natural substances like charcoal and coloured earths
(ochres) were used as printing paste with oils and fats, and applied as a kind of paste
Chapter 1 Textile Colouration
23
with people’s hands to decorate their body, caves and containers [9]. The origin of
earliest textile printing has not yet been established, but it is likely it originated from
China, India, Egypt or the East. Unfortunately, the sole early examples of printed
textiles have only survived on account of the dryness of the Egyptian environment
while in other climates have degraded quickly. In reviewing the various printing
processes, there are three stages that may be distinguished in the historical
development of textile printing. The first stage is simple hand printing of dyestuffs to
form the design pattern, or alternatively painting on a fabric first with a special resist
chemical, which can form a barrier to the dyestuff, and then dyeing the whole fabric
apart from the “protected” areas (resist printing). The second stage consists of a wide
range of techniques for the purpose of taking the artist’s original artwork and
reproducing it more rapidly. In this stage, the dyeing processes are manual and
semi-automatic, such as the surface (block), intaglio and screen methods. The most
advanced stage involves an enormous increase in the degree to which mechanisation
is utilised, such as the fully automatic screen printing and ink jet printing [10].
1.3 Classification
1.3.1 Textile printing
There is no classification system for textile printing. However, it can be broadly
categorised into four different styles: direct, discharge, resist and mordant style. Of
these, the last two processes are the oldest [3].
The principle of direct printing is to print directly onto the white or pre-dyed fabric.
Therefore, the printed pattern is usually much deeper in colour than the background.
It is the most common method in the textile industry, especially in terms of pigment
printing. It does not require any pre-treatment or application of mordant to the fabric
and fixation is achieved just by steaming or dry baking [11].
Chapter 1 Textile Colouration
24
Secondly, the discharge style is a process involving dye destruction which replaces
the original colour by a white or coloured pattern. Therefore in this process it is
necessary to dye the fabric first and then apply the discharge paste on specified area,
pre-determined for the design [9]. There are several factors that are necessary to
consider when patterning: the type of dyes needed to colour the background, the
discharging agent to choose in the illuminating areas, the associated print auxiliaries
and their effect on the final print, and finally the type of thickener required to control
the discharge chemicals and dyes [11].
Thirdly, the resist style produces a visual effect which is almost the same as in the
discharge style. Consequently, it can be difficult to distinguish them. However, the
printing process of resist style is opposite to the discharge style. The motif is printed
on the fabric with the resist agent, which may be composed of rice paste, clay or
some type of wax prior to colouration. In this way, the colour is just dyed on the area
not covered by resist agent [9]. Either a white resist or a coloured resist can be
achieved in this style.
Lastly, the mordant style is different from the resist style because here, the colour
adheres only to the area where the mordant has been applied. For the colourants
which are obtained from animals and vegetables, a fixing agent (mordant) needs to
be used in conjunction with colourant. Once the fabric was dyed, only the area to
which mordant was applied area formed an insoluble colour after fixation, whereas
the non- mordanted parts were washed clear and clean in water [3].
1.3.2 Textile dyeing
Textile material colouration can be achieved in a number of different ways, and
classifications can be made mainly by the categories of dye used [7, 12]:
Chapter 1 Textile Colouration
25
In direct dyeing the dye in the aqueous solution in contact with the material is
gradually absorbed into the fabrics due to its inherent substantivity for the fibre. This
type of dyeing includes the following dyes: acid dyes, direct dyes, basic dyes,
reactive dyes, and disperse dyes.
Alternatively, dyeing can be achieved with a soluble derivative of the dye, which
forms an insoluble pigment within the fibres following the appropriate treatment
after dyeing. This category encompasses: vat dyes and sulphur dyes. Moreover the
water soluble uncoloured precursors can be adsorbed into the fibre and for the
insoluble dye stuff in situ, i.e. the azoics.
Lastly, pigmentation is a process whereby pigment is bound to the surface of the
fibres through the use of an appropriate binder or by mass pigmentation in synthetic
fibres [7, 12].
All of these methods, except the last, require that the fibres, at some stage, absorb
the dye or an appropriate precursor from a dyeing solution. This absorption process
is essentially reversible. However, pigmentation and covalent bonding of the
reactive dye with appropriate functionalities, such as hydroxyls in the fibre are
irreversible processes [7].
1.4 Textile colouration of cotton
1.4.1 Cotton fibres
Cotton fibres are related to mallows, hollyhocks, and hibiscus, and all kinds of the
mallow family (Malvaceae) [13]. The word cotton is derived from Arabic, Qutun or
Qoton, which refers to a “plant found in a conquered land”. It is the purest
cellulose-based plant in nature [14]. Representing one of the most useful natural
Chapter 1 Textile Colouration
26
fibres, cotton production occupied 42.8% of the whole world fibre production [15].
The complex structure of cotton fibres only becomes apparent when observed under
an optical or electron microscope. The cotton fibre has a flat ribbon-like structure
with occasional convolutions along its length, as shown in Figure 1.1. These prevent
parallel fibres from sliding off each other, thus imparting the strength of the yarns
when they are spun together [2].
Figure 1.1 Scanning electron micrograph of cotton fibres
The morphology of the cotton fibre can be differentiated into four parts: the cuticle,
the primary wall, the secondary wall and the lumen, Figure 1.2 [16].
Figure 1.2 Morphology of the cotton fibre [17]
Chapter 1 Textile Colouration
27
The cuticle covers the primary wall with a waxy film which is composed of fats,
waxes and pectin. It is degraded and more or less removed during scouring and
bleaching processes in order to improve the water-absorbent properties [18]. The
majority of the fibre (about 90%) is formed by the secondary wall, which essentially
consists of three layers. The first two, which are next to the primary wall, consist of
entwined cellulosic fibrils of varying pitch. In some cotton fibres, there is also a thin
third layer which consists of mineral salts and proteins [19]. The lumen is the central
vacuole which is used by the growing fibre to provide nutrients and deposit cellular
wastes. Due to the evaporation of the sap, the components dry out and impart the
colour of the cotton fibre. The lumen then collapses and imparts to the cotton fibre
its characteristic ‘kidney bean’ shape [17].
Linear cellulose polymer is the major component of the cotton fibre, typically 65-70%
crystalline and 30-35% amorphous, with cellobiose consisting of two glucose units,
the repeating unit of the cotton cellulose polymer [14]. The degree of polymerization
of cotton cellulose ranges from 6,000 to 10,000.
Figure 1.3 Cellulose polymer
1.4.2 Colourants for cotton
Cotton fabric can be coloured using a relatively large range of colourant classes
including pigments, direct, reactive, sulphur, azoic and vat dyes [17]. Each class has
its own performance and application advantages and disadvantages. However, a key
factor in the success of the colouration process is to ensure that the fabric has been
well-prepared for the purpose of removing surface impurities, ensuring uniform
Chapter 1 Textile Colouration
28
uptake of the dye, good dye penetration into the fibre and avoiding any non-uniform
faults. Most of the deficiencies in the cotton fabric preparation will become more
apparent after dyeing and printing and cause commercial problems. The essential
desizing, scouring and bleaching operations are applied to the cotton fabrics to
remove the impurities [17]. Mercerisation is also considered as a useful treatment to
achieve fabric colouration uniformity and obtain a deeper shade by increasing the
uptake of dye [17].
Pigment printing is suitable for most types of fabric compositions, so accordingly it
is a very common colourant in textile dyeing and printing. Pigments are used in two
ways to colour fabrics. For colouring cotton, they are used together with binding
polymers to achieve a localised surface colouration, but also to some extent in so
called “pigment dyeing” where all areas of the fabric are treated [12].
Direct dyes are soluble anionic dyes which have substantivity for cellulosic fibres,
and are mostly applied from an aqueous dye bath with an electrolyte such as sodium
chloride [17]. They consist of an aromatic structure which contains one chromogen,
an auxochrome and typically several solubilizing groups. Direct dyes were the
earliest dyes to dye cellulosic fibres directly with no pre-treatment of the fibres with
a mordant, hence their description as “direct” dyes. The major groups of the direct
dyes are disazo and trisazo derivatives [20]. As one of the most easily applied dyes
for cotton, direct dyes are widely used as ‘fashion’ dyes where high performance is
not demanded. The cost of direct dyes is relatively low and the spectral range of
colours is relatively large. Their fastness properties, however, are in general low, in
particular the wet fastness. Nevertheless the fastness properties of direct dyes can be
improved by the diazotisation of the dye, crease resist treatment of the direct dyed
fabric, after coppering of the dyed substrate and a cationic fixing agent
aftertreatment of the direct dyed fabric [17].
Chapter 1 Textile Colouration
29
Reactive dyes are different from other dye application classes in that they can react
chemically with cellulosic fibres by forming covalent bonds. In order to facilitate
and maximise the covalent bonding alkali is commonly added to the aqueous
processing media. The amount of reactive dye, which can exhaust into the cotton
fibres, is related to their substantivity. They are not required to have low solubility in
water to achieve great fastness but rather need to be highly substantive to the
cellulosic fibres. Therefore, reactive dyes can be designed to be relatively small,
simple molecules. In fact, their relatively low molecule weight is often beneficial, in
order to achieve good penetration and uniformity within the fibres before chemical
reaction [19]. However despite “chemical engineering” the reactive dye 50% of the
cost of dyeing is still spent on washing off unfixed dye and effluent treatment.
Reactive dyes provide a comprehensive range of colours with good brightness,
excellent wash fastness, stability to peroxide bleach and moderate to very good light
fastness. However reactive dyes are comparatively expensive dyes [17].
Vat dyes are mainly divided into two chromophore categories, the anthraquinonoid
dyes and the indigoid dyes, with both offering a wide range of molecular structures
[19]. Vat dyeing is the process where a water insoluble aromatic keto-substituted
colourant is reduced by alkali and a reductive agent to form a water soluble leuco
compound which is substantive to cellulose. This reduced product will penetrate into
the fibre, and it is then re-oxidised back to the original insoluble form. Two or more
keto (C=O) groups, which are separated by a conjugated system of double bonds,
typically occur in the dye. There are highly condensed aromatic ring systems in most
of the anthraquinone derivatives. Indigo is a relatively poor performance dye and its
substantivity to cellulose is lower than other dyes but nevertheless due to its
widespread use in fashion garments is still widely used.
Similar to vat dyes, sulphur dyes are low solubility dyes which are applied as water
Chapter 1 Textile Colouration
30
soluble reduced leuco compounds under alkali conditions. In this case during the
dyeing process only sodium sulphide is incorporated to act as both an alkali and
reducing agent. Sulphur dyes are similarly widely used in view of the fact that they
provide a combination of a comparatively simple method to dye cellulosic coupled
with good-to-excellent wash and light fastness at a low cost. Their price is lower
than vat dyes, and they are usually used to impart deep colour shades to cotton.
Typically the shades are confined to black, mauves, olives, Bordeaux and reddish
browns [21]. The main drawbacks of sulphur dyes are their spectral limitation to dull
colours, and their relatively poor light fastness and stability to peroxide in pastel
shades [20].
1.5 Textile colouration for polyester
1.5.1 Polyester
As opposed to cotton as a natural fibre, polyester is an important class of synthetic
fibres. Polyethylene terephthalate and cellulose acetates are the most important
polyesters from a commercial point of view, with polyethylene terephthalate (PET)
being the most widely used fibre in the manufacturing of textile products because of
its good performance properties. However, PET is derived from fossil fuel for its
raw materials, which are the main cause of greenhouse emissions and in addition the
disposal of synthetic fibres creates carbon dioxide after incineration. It is the carbon
dioxide emissions which contribute significantly to global warming. Environmental
concerns call for materials which are developed from renewable resources and in the
textile sector biodegradable polyesters such as Poly (lactic acid) (PLA) are regarded
as potentially significant in addressing these concerns [22].
Generally, good physical and chemical properties are required for textile fibres
during processing and in domestic end-use. Physical properties are principally
Chapter 1 Textile Colouration
31
concerned with the mechanical aspects, which include tensile, tear and bursting
strength while chemical properties reflect the stability of fibres during processing
and during their use, in particular the thermal and hydrolytic processes. Table 1.1
details the physical and chemical properties of several kinds of polyester fibres [23].
Polyesters are produced with raw materials from various sources, for example, the
first polyester, acetate rayon, was manufactured from the acetylation of cellulose and
although still produced, their output has decreased.
Table 1.1 The physical and chemical properties of polyester fibres
Property PET PCDT 2o Acetate 3
o Acetate PLA
Chemical
class Aromatic
Aromatic-
Aliphatic
Modified-
carbohydrate
Modified-
carbohydrate Aliphatic
Specific
gravity 1.39 1.23 1.30 1.32 1.25
Tenacity
(gm/d) 2.4 ~ 7.0 2.5~3.5 1.1~1.3 1.2~1.4 2.0 ~ 6.0
Elastic
Recovery
(5% strain)
65% ---- 45 – 65 % 50 – 65 % 93%
Glass
Transition
Temperature
(Tg) ℃
125 ---- ----- ----- 55~60
Melting
Temperature
(™) ℃
255 290 232 300 130 ~
175
LOI (%) 20 ~ 22 ---- ---- ---- 26 ~ 35
Refractive
Index 1.54 ---- ---- ----
1.35 ~
1.45
Moisture
Regain (%) 0.2 ~ 0.4 0.4 6.5 4.5 0.4 ~ 0.6
UV
Resistance Fair ---- ---- ---- Excellent
Alkali
Resistance Good Good
Little effect up
to pH 9.5
Attacked by
strong alkalies Poor
Acid
Resistance Good Good
Strong acids
decompose
Strong acids
decompose Fair
Chapter 1 Textile Colouration
32
1.5.1.1 Poly (ethylene terephthalate) Fibres
PET fibres are produced for the varying requirements of textile applications, such as
mono-filament, multi-filament, staple fibre and tow in a wide range of counts and
staple lengths. These fibres are available in bright, semi-dull and dull lustres and
usually produced in circular cross-section. Crimped and textured yarns can also be
also made since PET is a thermoplastic [23, 24].
Poly (ethylene terephthalate) is created by the condensation polymerization of
ethylene glycol and terephthalic acid or dimethyl terephthalate, Figure 1.4. When the
polymerization has achieved a certain polymer length, the polymer is extruded into an
endless ribbon and then cut into small pieces. After being melted in an inert
atmosphere at 260℃, these chips are extruded into continuous filaments which are
stretched to about five times their original length in order to achieve the required
mechanical strength [23, 24].
Figure 1.4 Chemical synthesis of PET
1.5.1.2 Poly (lactic acid) Fibres
Polylactic acid (PLA) is the first melt-spun fibre where the raw material is obtained
from sustainable resources and is a rigid thermoplastic aliphatic polymer [25]. PLA
molecules have a helical structure, the reversed carbonyl functional groups, and it can
be semi-crystalline or completely amorphous, depending on the stereo-purity of the
polymer backbone [26].
Chapter 1 Textile Colouration
33
PLA mostly behaves like PET, but also performs similarly to the polyolefin
polypropylene (PP). Therefore PLA usage can cover a wide range of applications
due to its ability to be modified by stress and heat, impact modified, filled,
copolymerized, and processed in most polymer processing equipment. It can be
manufactured into transparent films, fibres and injection bottles. PLA can also be
used as an excellent material relating to food contact and related packaging
applications [27].
1.5.2 Dyeing polyester
Since polyester fibres are hydrophobic and do not swell in water, penetration by
water and water-soluble dyes is difficult. Against this background, the development
of disperse dyes was a logical solution to the colouration of polyester fibre. Disperse
dyes are typically non-ionic, sparingly soluble in water even at a very high
temperature of 130℃ and held in aqueous dispersion by surface-active agents [2,
28]. These types of dyes exhibit good light fastness, variable heat fastness and good
wash fastness [20]. Polyester fibres are essentially undyeable below 70-80℃, and
accordingly atmospheric dyeing below 100℃ can only be achieved using carriers [2,
18]. The other alternative is to dye polyester at temperatures above 100℃ using
pressurised vessels. Temperatures as high as 140℃ are used and results in the
amorphous molecular structure of polyester becoming more “open and mobile” and
the diffusion of dye into the fibre is faster and commercially acceptable [2].
When polyester is dyed by disperse dyes, some of the dye is deposited on the
fibre/fabric surfaces. It is essential to remove these residual dyes otherwise the washing
and rubbing fastness of the dyed fabric could be decreased and cross-staining could
increase during laundering. Normal washing or soaping is not strong enough to remove
the surface deposits due to the “insolubility” of disperse dyes. Accordingly a reduction
clear, based on an alkaline reductive treatment, is commercially utilised [29, 30].
Chapter 1 Textile Colouration
34
Sodium dithionite and sodium hydroxide are the most widely used reducing agent.
Some of recently introduced commercial disperse dyes do not require a reductive
environment. They are termed as “Alkali clearable” since alkaline scouring conditions
are sufficient to remove them [7, 31, 32].
In addition to using disperse dyes colouration of polyester can be achieved
incorporating pigments in the mass pigmentation process during fibre extrusion.
Typically the pigments are dispersed in the molten polymer immediately prior to its
extrusion. The pigments which are used for this process must be stable even under
the high temperatures employed in extrusion (about 230℃) [19].
1.6 Machinery
1.6.1 Dyeing machinery
A wide range of machines are available for the dyeing of textile fabrics due to the
fact that textile materials can be dyed at different stages of manufacture, and can be
processed batchwise, semi-continuously and continuously. The dyeing process can
be applied at the loose fibre, tow, yarn, fabric or garment stages. The choice of at
which stage of manufacture to dye, depends on various factors, undoubtedly the
most important of which are cost and fashion considerations. In recent years, late
stage dyeing has increased enormously in order to avoid over-production of
unpopular colours and to respond quickly to repeat orders of those which are more
popular for those manufacturers [19].
The essential aim of the dyeing process is to transfer the dye molecules from the dye
solution into the fibre in a uniform and efficient approach. The rate of dye taken up
by the fibre is increased by the movement of the dye liquor around the fibres [19].
There are three main processing or mechanical principles usually employed for
Chapter 1 Textile Colouration
35
dyeing textiles: (a) the dye liquor is moved and the textile is stationary; (b) the
textile is moved and the dye liquor has no mechanical movement; (c) both the dye
liquor and the textile move or mechanical agitated [33]. During the dyeing process,
three distinctive stages can be identified: (a) transfer of dye from the bulk solution to
the fibre surface; (b) adsorption of dye onto the fibre surface; (c) diffusion of dye
from the surface in to the fibre [19].
1.6.1.1 Dyeing in the loose fibre form
The main advantage of dyeing textile in loose fibre form is the ease of circulation of
the dye solution through the fibres and the fact that any unlevelness in dyeing can be
randomised during the following carding and spinning procedures. The method has
conventionally been employed more for dyeing wool than cotton or synthetic fibres,
especially the application of acid milling dyes due to their relatively poor migration
properties. However, even in the dyeing of wool, the extent of loose stock dyeing
has been reduced in recent years [19].
The most common types of this kind of machine holds the textile materials in a
tapering pan with perforated inward sloping sides, or in a perforated cage. After the
fibres are gradually packed into the pan, they are wetted and compressed by
screwing down a solid plate which is laid on the fibrous top [7]. Another type of
machine is the radial flow type where the fibres are held in a cage of about 150cm
diameter, with perforated sides and a central perforated column.
1.6.1.2 Dyeing yarn
Yarns can be dyed in two different forms: hank and package. Hank dyeing has
always been carried out on yarns which are inherently bulky in nature, while
package dyeing is used for thinner yarns [19]. Nowadays, most yarns are dyed as
packages, which are wrapped around a series of hollow, perforated vertical spindles
Chapter 1 Textile Colouration
36
set around the circular vessel containing the dye liquor. The whole system is
generally in a cylindrical vessel with a round bottom and lid. Appropriate pumps
drive dye liquor, which is reversed from time to time, up through the hollow spindle
and through the wool packages [2].
1.6.1.3 Dyeing fabrics
A variety of machine types are available for dyeing fabrics and the choice of
machine used depends on the nature of the fibre (e.g. wool, cotton, polyester, etc.)
and the structure of the fabric. At the same time, the quantity of cloth to be dyed will
decide whether a batch or continuous process is employed [19].
Winch dyeing machine
The winch or beck dyeing machine, which is quite simple compared to other dyeing
machines, and is able to function in other wet processing such as scouring, bleaching,
dyeing, washing-off and softening. It is the oldest kind of equipment used for dyeing
fabric [2]. A length of fabric with the ends sewn together forms a continuous rope
and the rope passes through the dyebath driven by two elevated reels and follows to
fall back into the bath. The jockey or fly roller, shown in Figure 1.5, is free-running
to act as a support for the rope while it is pulled forward. The winch reel, over which
the rope of fabric is looped over, is driven and controls the rate of rope
transportation and the amount of pleating where the rope accumulates below and
behind the winch. The fabric rope is held on the winch due to its own weight and
friction that can be improved by covering the winch roller with polypropylene or
polyester tape. Once the fabric drops into the dyebath, it turns fold over and the
pleating and opening action keeps the dye liquor flowing through the fabric [2, 7].
Chapter 1 Textile Colouration
37
Figure 1.5 Winch dyeing machine
Jig dyeing machine
The jig or jigger dyeing machine is one of the oldest types of machine which can
dye a variety of materials in open width, Figure 1.6. It is particularly suited for
fabrics such as satins and taffetas that are readily creased. The open-width fabric is
moved from one roller through the dye liquor at the bottom of the machine and then
onto another roller on the other side. The direction of movement is automatically
reversed when all the fabric has passed through the bath. The dyeing duration is
controlled by the number of passages, which is called ends, through the dye liquor.
Dyeing always consist of an even number of ends in order to ensure uniformity [2,
7].
Figure 1.6 Jig dyeing machine
Chapter 1 Textile Colouration
38
Beam dyeing machine
In theory, beam dyeing is similar to yarn package dyeing but with a single large
package used instead, Figure 1.7. Beam dyeing involves winding fabric onto a
perforated beam and pumping dye liquor through the beam and through the fabric
layers [7]. The machines are usually pressure vessels, which can be operated at high
temperatures. The largest vessels can be 4.5 metres and the internal diameter is
nearly 2 metres, and can accommodate beams with approximate 7000 metres of
fabric [19].
Figure 1.7 Beam dyeing machine
Jet dyeing machine
Jet dyeing machines based on the principles of winch dyeing, were gradually
developed from the 1960s, Figure 1.8. In this kind of machine, the fabric rope is
moved by the high-speed dye liquor injection and the fabric folds around the
machine before passing through the jet to start another cycle. 200-250 m/minute is
the usual fabric speed, but higher speeds can be achieved. A typical complete cycle
of the rope takes about one minute [7, 19].
Chapter 1 Textile Colouration
39
Figure 1.8 Jet dyeing machine
1.6.1.4 Continuous dyeing equipment
The major types of fabrics which are dyed continuously are either 100% cotton or a
blend of cotton/polyester and cotton/viscose. For dyeing cotton or the cotton
component in blends, reactives, vats, sulphurs and directs are usually used, whilst
disperse dyes are used for the polyester. In the dyeing process of blends, the dyes
can be applied either together, when they must be compatible with each other and
with the particular auxiliaries in the dyebath, or separately [19]. Continuous dyeing
of fabrics basically involves padding, drying and fixation, Figure 1.9.
Padding
The fabric is first immersed in the dye solution or dispersion and then passed in
open width through a padding mangle nip to squeeze out the excess dye liquor [2].
The aim of this stage is to mechanically impregnate the fabric with dye and
appropriate dyebath auxiliaries, so uniformity in this process is vital [7]. The
duration of immersion of the fabric in the liquor, the time of contact with the nip
rollers and the pressure that those rollers exert on the cloth are all the aspects
Chapter 1 Textile Colouration
40
affecting the uniformity of the distribution of any chemicals in the padded fabric
[19].
Drying and fixation
After the padding operation, in order to avoid unwanted migration of the dye, it is
required to dry the fabric in a controlled manner. Firstly the fabric is pre-dried,
which involves passing the fabric through a bank of infra-red heaters to remove
about 50% of the water. Then all moisture is removed by a conventional drying
machine, such as cylinder cans [19]. The disperse dye is transferred from the cotton
fibre surface into the polyester by sublimation of the dye during the thermosol
process. A steamer is utilized for the continuous fixation of vat, sulphur, reactive and
direct dyes on cotton, especially in blends with polyester. The padded fabrics pass
through a zone which fills with saturated air-free steam for about 20-60s [7].
Figure 1.9 Continuous dyeing equipment
1.6.2 Printing machinery
There are five major methods to print a fabric: the block, roller, screen, heat transfer
and ink-jet printing systems. Only the heat transfer method is distinctly different
because this printing is transferred from a designed and coloured paper while the
other methods are printed through a print paste medium [19]. Block printing,
Chapter 1 Textile Colouration
41
conventional roller printing and hand-screen printing were the three earliest methods
used, and the ink-jet printing method is a relatively new innovation [33].
Block printing
Block printing usually includes applying the printing paste to the designed surface of
wooden blocks to make an impression on the fabrics, and the process is repeated
with varying design blocks and colours until the pattern is complete. However, today
in commercial textile printing operations, this method is rarely used [19, 33].
Roller printing
Roller printing machines underwent few major changes since the first of these
machines was introduced in the 1780’s. They are extremely durable because the
cylindrical print rollers are copper, in which the design is etched. There are separate
rollers for printing each colour. The fabric passes around a large cylinder which is a
pressure bowl covered by a thick layer, the lapping. A blanket and backing cloth
travel around the lapping under the fabric and provide a resilient backing and
flexible support [2, 19]. The printing paste is shifted from a reservoir or trough onto
the surface of the engraved rolls, and a steel doctor blade completely removes the
colourant on smooth areas of the roller. Under pressure, colour is transferred from
the engraved rolls to the fabric surface.
Screen printing
Screen printing has grown from a specialized, labour-intensive art (hand printing or
silk screening on long tables) to a highly mechanized process, using flat and rotary
screen printing machines. Screen printing is a process in which the printing paste is
transferred to the fabric through a stencil or screen which is usually made of silk,
polyester, polyamide or nickel mesh. For the traditional hand screen printing, the
fabric is rolled out and fixed in place on long tables (up to 100 yards in length)
Chapter 1 Textile Colouration
42
which are covered by waterproof covers. Then the screen is placed on the surface of
the fabric and the printing paste is drawn across the screen in a transverse direction
to the fabric length with a rubber squeegee blade. Different screens are used for
different colours. In rotary screen printing, movement of the screen produces the
dynamic pressure which is “neutralised” by the penetration resistance of the fabric
and flow resistance of the screen [33].
Heat transfer printing
In this kind of printing, a designed and coloured paper is prepared before printing
the fabric. The colourants used on paper are volatile disperse dyes that are capable of
being sublimed at elevated temperature. When the paper is heated and held in
contact with the fabric, the dye is transferred to the textile fabric in the vapour phase
[9].
Ink-jet printing
This type of printing has been developing rapidly in recent years following its
primary use for the colouration of paper and documents, and has been adapted to
print on textiles. This type of printing is illustrated by a non-contact method that
emits drops of ink on the surface of the substrate to be printed, and at the same time
affords high print quality art and high speeds. There are two important types of
ink-jet printers, which are the continuous type characterised by high speed and cost
and the drop-on-demand (DOD) or impulse jet printer [33].
1.7 References
1. Johnson, A. E., The Theory of Coloration of Textiles. 2nd. ed. 1989,
Bradford: Society of Dyers and Colourists.
2. Ingamells, W., Colour for Textiles: A User's Handbook, 1993, Bradford:
Society of Dyers and Colourists. vii,179p.
Chapter 1 Textile Colouration
43
3. Storey, J., The Thames and Hudson Manual of Textile Printing. Rev. edn.
1992, New York, N.Y.: Thames and Hudson. p.192.
4. Cegarra, J., Puente, P., and Valldeperas, J., The Dyeing of Textile Materials:
The Scientific Bases and the Techniques of Application, 1992, Biella:
Textilia. p.703.
5. Joseph, M. L., Introductory Textile Science, 5th ed. 1986, New York; London:
Holt, Rinehart and Winston. xv, p.432.
6. Hall, A. J., A Handbook of Textile Dyeing and Printing, 1955, London:
National Trade Press. vii, p.216.
7. Broadbent, A. D., Basic Principles of Textile Coloration, 2001, Bradford:
Society of Dyers and Colourists. xiv, p.578.
8. Waring, D. R. and Hallas, G., The Chemistry and Application of Dyes, 1990:
Plenum. p.414.
9. Miles, L. W. C., Textile Printing. Rev. 2nd edn. 2003, Bradford: Society of
Dyers and Colourists. X, p.339.
10. Dhariwal, J., An Investigation into the Effect of Pigment Printing on Fabric
Handle, 1996, MSc Thesis, UMIST.
11. Wells, K., Fabric Dyeing & Printing, 1997, London: Conran Octopus. p.192.
12. Carr, C. M., Chemistry of the Textiles Industry, 1995, London: Blackie
Academic & Professional. xiii, p.361.
13. Kassenbe, P., Bilateral Structure of Cotton Fibers as Revealed by Enzymatic
Degradation, Textile Research Journal, 1970. 40 (4), p.330.
14. Joseph, M. L., Joseph's Introductory Textile Science. 6th edn., 1992, Fort
Worth: Harcourt Brace Jovanovich College Publishers. xiv, p.417.
15. Society of Dyers and Colourists and A.A.T.C.C, Colour Index. 3d edn., 1971,
Bradford.
16. Cockett, S. R. and Hilton, K. A., Dyeing of Cellulosic Fibres and Related
Processes, 1961, London: Leonard Hill, p. 417.
Chapter 1 Textile Colouration
44
17. Shore, J., Cellulosics Dyeing, 1995, Bradford: Society of Dyers and
Colourists. ix, p.408.
18. James, W., Practical Textile Chemistry: with Special Reference to the
Structure, Properties and Processing of Wool, 1955: National Trade P. p.259.
19. Christie, R. M., Mather, R. R., and Wardman, R. H., The Chemistry of
Colour Application, 2000, Oxford: Blackwell Science. viii, p.288.
20. Rivlin, J., The Dyeing of Textile Fibers: Theory and Practice, 1992,
Philadelphia: J. Rivlin. xiii, p.220.
21. Parfitt, M., Investigation into the Surface Chemistry of Cotton Fibres, PhD
Thesis, UMIST, 2001.
22. Blackburn, R. S., Biodegradable and Sustainable Fibres, 2005, Cambridge:
Woodhead. xxii, p.546.
23. Cook, J. G., Handbook of Textile Fibres. 5th ed. Edn. 1984, Shildon:
Merrow.
24. McIntyre, J., Synthetic Fibres: Nylon, Polyester, Acrylic, Polyolefin, 2005,
CRC Press.
25. Drumright, R. E., Gruber, P. R., and Henton, D. E., Polylactic Acid
Technology, Advanced Materials, 2000, 12(23): p.1841-1846.
26. Hoogsteen, W., Crystal Structure, Conformation and Morphology of
Solution-spun Poly(L-lactide) Fibers, Macromolecules, 1990, 23(2):
p.634-642.
27. Schmack, G., Biodegradable Fibers of Poly(L-lactide) Produced by
High-speed Melt Spinning and Spin Drawing, Journal of Applied Polymer
Science, 1999, 73(14): p.2785-2797.
28. Bogle, M., Textile Dyes, Finishes and Auxiliaries. Rev. edn. Garland Library
of Textile Science and Technology, v 11977, New York: Garland Pub. xiii,
p.166.
Chapter 1 Textile Colouration
45
29. Nunn, D., The Dyeing of Synthetic Polymer and Acetate Fibres, 1979, Dyers
Co. Publications Trust.
30. Moncrieff, R. W., Man-made Fibres, 1975: Newnes-Butterworths London.
31. Aspland, J., Vat Dyes and Their Application. Textile Chem. Color, 1992.
24(1): p.22-24.
32. Provost, J. R. and Connor, H. G., The Printing of Polyester/Cellulose
Blends‐A New Approach. Journal of the Society of Dyers and Colourists,
1987. 103(12): p.437-442.
33. Vigo, T. L., Textile Processing and Properties : Preparation, Dyeing,
Finishing and Performance, 1994, Amsterdam ; London: Elsevier. xvii,
p.479.
Chapter 2 Pigment Colouration
46
Chapter 2 Pigment Colouration
2.1 Definition and overview
Colouration of textiles can be achieved by using a pigment through printing or mass
pigmentation. Unlike dyes which are absorbed into the fibre, pigments due to their
insolubility and their lack of affinity for fibre, when printed, are usually in the form
of dispersions and mixed into the print paste or dyeing solution containing binders,
thickeners and other auxiliaries [1]. Therefore, pigment printing is a physical process,
in which there is no reaction between pigment and fabric. After the printing, drying
and curing processes, unlike other textile colouration processes there is no necessity
for after-washing, which reduces costs and eliminates associated pollution [2, 3].
Pigment dyeing and printing as a part of the wider textile colouration sector is
becoming increasingly popular and important. When printed the print paste includes
thickeners while for pigment dyeing system the thickener is omitted. Further,
pigment dyeing can be subdivided into pigment exhaustion dyeing and pigment pad
dyeing. The early method of pigment dyeing proved to be unsuccessful because of
low exhaustion and poor uniformity, but later alternative auxiliaries were introduced
to improve the pigment dyeing quality [4]. Although of lesser significance today
than pigment printing, pigment dyeing still offers significant potential.
2.2 History
About 30,000 years ago, Palaeolithic man discovered the use of pigments for
decoration and was undoubtedly the easiest and earliest application method for
colouring fabrics. Some of the pigments used were earth pigments, for example,
natural iron oxides and carbon black from soot although early prints tended to be
stiff and easily faded [5]. Millennia later the period following the Second World War
Chapter 2 Pigment Colouration
47
was characterized by a concerted period of focused further development of pigment
colourants. However prior to the war in 1937, the first modern pigment printing
system, the Aridye system, was introduced by the Interchemical Corporation, but
there were so many limitations that it was not widely adopted [6, 7]. However
progressively there was a dramatic growth in the use of pigment printing, especially
from the 1960s onward when aqueous dispersions of film-forming binders
composed of self-crosslinking copolymers became established [7]. Subsequently
pigments gradually achieved a dominant position in the textile printing sector with
now more than 50% of all textile prints being pigment-based [1].
2.3 Pigments
2.3.1 Definition
Pigments are particles which are not soluble in typical liquid media which is in
obvious contrast to dyes [3, 8]. However they can be mechanically dispersed in a
specific medium to improve its colour or light-scattering properties [9]. For
pigmentary purposes, the range of particle sizes from very fine colloidal particles
(~0.01μm) to relatively coarse particles (~100.0μm) [10].
2.3.2 History
Discoveries by archaeologists indicate that earth pigments were the earliest
colourants used to decorate both people and their possessions. Earth pigments were
probably first recognized simply because their colours stood out when hard lumps of
rock were examined. Such rocks were smashed and the desirable colour was
extracted. The coloured rocks were then ground to fine powder and blown onto the
painting surface by a hollow tube, or mixed with fatty materials to form a kind of
natural paint which was applied with the fingers or a reed. Some of the prehistoric
cave paintings were based on this methodology and examples are widely distributed
Chapter 2 Pigment Colouration
48
around the world due to their high resistance to decomposition by heat, light and
weather. Indeed, without these excellent properties, pigments would not have
survived the many centuries.
Pigments have also been derived from natural colouring matter in many plants and
even in some animals. For example both the red pigment madder and the blue indigo
are extracted from plants, while cochineal and lac lake are derived from insects, the
much-prized Tyrian purple is obtained from certain shellfish, and finally sepia is
obtained from cuttlefish [11].
The era following the Second World War was the golden age for the development of
pigments. The manufacture of inorganic pigments began in the 19th
century, while
the production of organic pigments has always been a part of the dyestuff industry
since pigments became a secondary product of dyestuff manufacturing. Indeed
typically new chromophoric colourant systems were often first used as a pigment
[12].
2.3.3 Dyes and pigments
Colour may be introduced into manufactured objects, such as textiles and plastics, or
into a range of colour application media, such as paints and printing inks, for a
variety of reasons. Yet in most occasions, the ultimate purpose is to decorate and
improve the attractiveness of a product and enhance its market appeal [13]. Colours
are related to the region of the electromagnetic spectrum which can be recognised by
human eyes, that is, the range between 400nm and 700nm in which light is absorbed
at different wavelengths [14]. The resultant colour is generally achieved by the
individual colourants or as a combination of dyes or pigments. The term colourant is
commonly used to encompass both types of colouring materials [13].
Chapter 2 Pigment Colouration
49
Dyes and pigments are both commonly produced by the manufacturers as coloured
powders, and they may often be chemically quite similar. However, they are
specifically different in their properties and particularly in the way they are used.
Dyes and pigments are typically distinguished on the basis of their solubility
properties. Essentially, dyes are soluble, whilst pigments are insoluble. A
comparison of the general characteristics of dyes and pigments is presented in Table
2.1 [13].
Table 2.1 A comparison of the general characteristics of dyes and pigments [13]
Property Dyes Pigments
Solubility
Required to have solubility or
capable of solubilisation mainly
in water
Required to resist dissolution in
any solvents
Traditional
applications Textiles, leather, paper Paints, printing inks, plastics
Method of
application
Applied to textile fibres from an
aqueous dyebath solution
Dispersed into a liquid medium
which subsequently solidifies
Main chemical
types
Organic only: azo, carbonyl and
arylcarbonium ion etc.
Organic types: azo, carbonyl and
phthalocyanine; inorganic types
Application
classification
For textile applications, the
subdivision into dye application
classes is important
Pigments are multi-purpose
objects and application class is
relatively unimportant
Colour
properties Full range of coloured species
Include coloured, white and
metallic species
A further difference between dyes and pigments is that while dye molecules are
intended to be attracted strongly to the polymer molecules which constitute the
textile fibre, pigment molecules are not required to present such affinity for their
medium. Pigment molecules are, nevertheless, required to be attracted strongly to
one another in their solid crystal lattice structure in order to resist dissolution in
solvents [13].
Chapter 2 Pigment Colouration
50
2.3.4 Classification of pigments
The range of pigments can be divided into three main series according to their
chemical constitution and form of preparation for use: organic pigments
(approximately 60% of the total number of pigment products), water insoluble dyes
(approximately 20% of the total number of pigment products) and inorganic
pigments (approximately 20% of the total number of pigment products) [11].
Generally, organic pigments are characterised by high colour strength and brightness
and variable in the range of fastness properties which they offer. The properties of
pigments temporarily converted into soluble dyes are the same as the organic
pigment due to their organic nature and the reversible nature. Inorganic pigments
generally provide excellent resistance to heat, light, weathering, solvents and some
chemical attack. In these aspects, they have technical advantage over most organic
pigments although they suffer from the disadvantage of considerably lower intensity
and brightness of the colour compared with organic pigments. Additionally
inorganic pigments are usually significantly cheaper than organic-based materials
[13].
2.3.4.1 Organic pigments
Organic pigments are typically non-ionic colourants based various chemical
chromophoric classes [11, 12]. Organic pigments are usually brighter, purer, and
richer in colour than comparable inorganic pigments [10]. They can be treated with a
suitable surfactant and milled in order to reduce and optimise the particle size
(typically 0.03-0.5µm) and improve colour strength/yield [11]. The coloured organic
pigments are mostly used in the form of printing inks, followed by paints and
plastics. They are commonly used to print postage stamps and currency notes, and
different coloured organic pigments can be used to identify and differentiate cable
coatings, gas conduits, electric switches, yellow school buses and so on for safety
reasons [15].
Chapter 2 Pigment Colouration
51
Approximately 25% (by weight) of the organic colourant production is comprised of
organic pigments and this share of pigments compared with dyes is increasing. The
classification of organic pigments can be defined as either classical or high
performance pigments. Classical organic pigments mainly consist of azo pigments
and phthalocyanines, which are relatively inexpensive products and used extensively
in a large range of printing ink, plastics and paint applications. High performance
pigments are able to provide greater technical performance, usually at higher cost
and are more sophisticated in nature [13]. Some of the major organic pigments are
discussed in the following sections.
Azo pigments
Of the organic pigments azo compounds are considered as the largest group,
regardless of the number of different chemical structures or of the total production
volume. Normally azo chromophores are synthesised by diazotising a primary
aromatic amine, and then coupling this to a second component, usually a derivative
of beta naphthol, acetoacetanilide or pyrazolone. The commercial colour range
encompasses the yellows, oranges and reds [11]. Typical azo pigment structure, CI
Pigment Red 1 Para Red, is shown in Figure 2.1.
Figure 2.1 CI Pigment Red 1 Para Red
Phthalocyanine pigments
As the first new chromogenic type to be introduced into the field of organic pigment
Chapter 2 Pigment Colouration
52
chemistry, the development of phthalocyanine is interesting both technically and
scientifically. Before this discovery, making dyes insoluble and synthesizing new
insoluble azo compounds were the two approaches to develop all organic pigments
[11]. An important constituent in the phthalocyanine range of pigments is copper
phthalocyanine which provides almost all the important blue and green pigments.
Incorporating copper creates a pigment of outstanding resistance, strength and
brilliance of colour [16]. It is widely used in most pigment applications due to its
brilliant blue colour and its excellent fastness to light, heat, solvent, acids and alkalis.
Moreover, despite its structural complexity, copper phthalocyanine has a relatively
low price, Figure 2.2 [13].
Figure 2.2 Copper phthalocyanine
Quinacridone pigments
Quinacridone pigments are generally known generally as linear trans-quinacridones.
The linear trans-quinacridones are infusible or high-melting solids, insoluble in
normal solvents, non-bleeding/migrating and fairly heat resistant as pigments. In
addition, they are chemical resistant to both alkali and acid although their alkali
resistance is not suitable to use directly on concrete or glazed cement-asbestos
Chapter 2 Pigment Colouration
53
powders. They have good light fastness, particularly in light tints [11].
Figure 2.3 CI Pigment Violet 19
Fluorescent pigments
Fluorescent pigments are derived from fluorescent dyes which are soluble in certain
polymeric resins. A resin coloured in this manner is based on fluorescent pigment
powder, which is dispersed into the media in the same way as other pigments. The
overall impact is that the paints, printing inks and plastics into which fluorescent
pigments have been combined have very vivid bright colours which attract the eye
[11].
Figure 2.4 Brilliant sulfoflavine FF (yellow)
Chapter 2 Pigment Colouration
54
2.3.4.2 Water-soluble dyes
Water-soluble dyes are converted into insoluble dyes by means of various
precipitation techniques. Traditional dyes can be insolubilized by precipitation by
reacting with phosphomolybdic or phosphotungstic acids, or alternatively copper
hexacyanoferrate. These complexes show higher light fastness than their parent
basic dyes or a traditional tannate mordant. Although reducing in importance soluble
dyes can be converted into pigments by precipitation using an inert substrate such as
alumina hydrate [11].
Vat dyes, although they may be intended as pigments in view of their aqueous
insolubility, are typically used as dyes. When they are prepared for dyeing, their
particle size is a significant technical element which influences their rate of
reduction. When vat dyes function as pigments, particle size be even more
important.
2.3.4.3 Inorganic pigments
Inorganic pigments exist as the coloured natural minerals commonly used to
embellish ceramics, glass and many other artefacts [11]. Some of them are
single-component particles, such as oxides, hydroxides or sulphides, while others
are mixed-phase pigments, which contain mixed crystals of oxides or sulphides,
which are distinct from pigments that are pure physical mixtures.
This kind of pigment crystallises as a stable oxide lattice and the colour occurs by
reason of the incorporation of coloured metal cations in a variety of valency states
[17]. Some inorganic pigments are still in use commercially, and they can be
classified further as non-coloured pigments (hiding white pigments, non-hiding
white pigments, black pigments and metallic pigments) and coloured pigments [13].
Chapter 2 Pigment Colouration
55
Inorganic pigments play a special role in pigment chemistry for several reasons.
Some of them are relevant to culture heritage and history. For example, the colours
of oil paintings in the art galleries around the world were, until the industrial
revolution, produced entirely from mixtures of inorganic pigments obtained from
natural sources which are so-called earth pigments. Another reason why inorganic
pigments are so important is that there are no white organic pigments. White
pigments are fundamental to provide opacity to the paints and printing inks which
are used on metal, wood, paper, textile fabrics and plastic films. White inorganic
pigments are also applied to provide opacity to synthetic fibres and plastics
produced by moulding and extrusion processes [11].
2.4 Binder system
Since pigments have no affinity for the fibres/fabric, the polymeric binder plays an
important role in linking the pigment and fabric and influences the colour durability,
including wet, dry and washing fastness [18]. Pigment binders are polymer latexes
which are formed by selecting monomers which contribute specific properties to the
binder. The process, combining monomers together to form polymer, is called
polymerisation, and in pigment colouration it is called emulsion polymerisation [19].
There are several advantages offered by the emulsion polymerisation process, but
most of the polymer advantageous properties are due to the high molecular weight
improving the physical properties. An aqueous dispersion is the most common form
of binder, in which 40%-45% binder solids are incorporated into water [1, 7, 20].
The droplets are similar sizes with those of the pigment particles, at most, less than
0.5 microns in diameter.
After evaporation of the solvent or other dispersion medium on heating, the particles
coalesce together to form a thin coherent coating, the film, which is several micron
thick, enclosing the pigment particles and adhering to the fibre [7]. The binder film
Chapter 2 Pigment Colouration
56
is a three-dimensional structure with the first and second dimensions being more
important than the third [1]. A binder must be compatible with the pigment
application and have other characteristics to improve the colouring impact of the
pigment [21]. A “good” binder typically has following properties:
The binder film is tenacious and elastic;
The binder film should be colourless and transparent in order to present the
pigment hue efficiently;
The binder film should exhibit good flexing resistance, abrasion resistance,
chemical resistance and light resistance.
Binders are usually produced from synthetic polymers, but also natural wood resin,
wax, linseed or safflower oils and chitosan have been examined in order to
incorporate their biodegradability [22]. Following industrial trials chitosan has been
identified as the best choice and such ecologically friendly binders are already used
in production [22].
2.5 Softeners
Aside from appearance, the handle of the textile is also a very important quality
indicator for most manufacturers and customers. Accordingly, almost all apparel and
home furnishing textiles are treated with softeners [23]. During laundering there is
strong mechanical agitation giving rise to fabric deformation and harshening of the
fabric handle. Subsequent drying, particularly line drying sets this effect imparting
an uncomfortable hand. Similarly prior to domestic processing the binder utilised in
pigment printing and dyeing produces a stiffening of the fabric handle. In contrast
the use of low solubility alkali soaps in scouring processes resulted in incomplete
removal of the soap and the residual soap on the fibre imparted a softer feel and
generally a better handle to the fabric [24].
Chapter 2 Pigment Colouration
57
A softener can be defined as “an auxiliary that imparts a pleasant handle and
smoothness when applied to textiles” [25, 26]. The softening effect is not only
evident in the handle property but also produces easier ironing, sewing and other
operations in which friction affects the performance. Most softeners are composed
of molecules with both a hydrophobic and hydrophilic constituent. According to
their ionic nature and structures, softeners can be subdivided into three types:
cationic, anionic or non-ionic [27].
As the most important softeners, cationic softeners are most widely used and
achieve the best results. Their cationic character is typically based on a positive
charged quaternary ammonium ion [24, 28]. Since most textile materials possess a
negative charge when immersed in water, cationic softeners are electrostatically
attracted to the fabric surface. They usually are applied by exhaustion methods.
However, there are some problems due to the positive charge, such as when they
react with anionic dyes creating problems such as shade changes and colour
bleeding. Because of their interaction with anionic detergents, their wash fastness is
usually limited but can be improved by incorporating reactive functionalities into the
softener that can react with the fibre [24].
Anionic softeners with a negative charge are composed of hydrophobes linked to
anionic groups as carboxylates, carboxymethyls, sulphates, sulphonates or even
phosphates [28]. Anionic surfactants can be used as softening agents, wetting agents
and detergents, because they give a good handle after a domestic wash. They are
generally applied by padding due to the low affinity for most of the fibres.
Non-ionic softeners contain the similar hydrophobe chains to the anionic type, but
the hydrophobes are ethoxylated, R-(OCH2CH2)x-OH. Non-ionic softeners are
Chapter 2 Pigment Colouration
58
applied by padding method because they have little affinity for the textile fibres and
can be co-applied with other ionic or non-ionic textile chemicals/auxiliaries.
In addition, silicone softeners are based on a siloxane backbone, Si-O. They can be
emulsified in water and then pad applied onto the fabric, since they do not have a
high affinity for the fibre. Three types of silicones can be distinguished.
Polydimethylsiloxanes, which offer flexibility due to the elastic polymer backbone,
lacks affinity for the fabric and they tend to be removed during washing. They are
held to the substrate through weak intermolecular forces. In order to get better wash
fastness polydimethylsiloxanes with reactive groups were developed which can react
as a crosslinking agent and so gives elastomeric structures between the siloxane
chains. A further development of the siloxanes are the amino-functional type silicone
softeners which exhibit a slight cationic character due the NH group, especially in
acidic media, and exhibit higher affinity for the negatively charged fibre. However,
the primary and secondary amino groups can introduce yellowing during subsequent
processing and teriary derivatives need to be used [24].
2.6 Other Auxiliaries
Crosslinking agents
A crosslinker may also be incorporated into the binder formulation in order to
enhance the fastness of coloured fabrics [29]. However, an excess of the crosslinker
may result in an unacceptably stiff handle. The crosslinking process is typically a
condensation reaction involving formaldehyde-based derivatives which eliminate
water, and are required when the binder has no self-crosslinking groups, just reactive
groups for bonding to the substrate. When crosslinkers are applied to cellulosic
fibres, chemical bonds will also be formed between the binder and fabrics. A
crosslinker should be selected on the basis of optimised temperature, pH and curing
time. In addition the reactivity of the crosslinker needs to be considered in order to
Chapter 2 Pigment Colouration
59
ensure premature reaction does not occur in the print/dye paste leading to damage in
the subsequent film formed by the binder particles, or even cause the print paste or
dye solution to gel [7].
Thickeners
In pigment printing it is necessary to incorporate a thickener in order to achieve the
correct viscosity in locating the print motif correctly and preventing diffusion. In
pigment dyeing no such thickener is necessary. The thickener is usually a long chain
acrylic acid-based polymer, although both natural and synthetic thickeners are
commonly used [1]. It increases the viscosity of the paste so as to achieve sharp
well-defined patterning and uniform coverage. Water-soluble thickening agents are
macro-molecular substances, which may form a hard film which will cause a stiff
handle and would reduce the benefit of eliminating the washing off process in
pigment printing. Accordingly some of the polymer binder may provide the
thickening role as well as the pigment binding structure [7, 30].
Wetting agent
A further formulation additive is the wetting agent which expels air from the textile
assembly contained in the aqueous processing bath to lower the fibre/fabric surface
tension. This process increases spreading of the formulation and improves the
uniformity of the surface film. In continuous dyeing, a wetting agent is usually
added to pad liquors [22]. Typically the wetting agents are non-ionic or anionic in
nature although non-ionic surfactants have proved to be best wetting agents in
commercial practise and experimental tests [31].
Hand-modifiers
Hand-modifiers are mostly necessary in pigment colouration. Two types of hand
modifiers can be distinguished. The first chemical hand-modifier is the softeners
Chapter 2 Pigment Colouration
60
based on cationic, non-ionic and silicone chemistries [22]. These softeners can lower
surface friction, decrease stiffness and enhance rub fastness [1]. They will make the
binder film more flexible and impart a considerably softer hand [22]. Crosslinking
agents are again chemical in nature and increase fabric stiffness but also improve the
mechanical performance [1]. Handle modification can be achieved by the
mechanical processing (physical processing) as well, such as calendaring, pressing,
raising /cropping and shearing.
2.7 Pigment Application System
2.7.1 Print System
The pigment printing systems can be applied by textile printing machines which are
discussed in 1.6.2. Successful pigment printing systems are based on three equally
significant components: pigment dispersions; binders and crosslinking agents; and
thickeners and auxiliary agents giving the required rheology [1]. The printed sample
is passed through a drying section (usually a hot air oven) and then collected by
folding flat or winding up on a rolling device. The dyed fabric is then sent through
another heat stenter to cure the binder system and achieve polymerization of the
resin. The curing step is often incorporated with the drying step or it can be
combined with a post cure procedure [21]. Environmental impact gains even more
importance when preparing pigment printing paste. In particular toxicological
aspects lead to the development of paste in which hazardous substances are reduced.
Further development has led to biodegradable printing pastes, such as binders made
of chitosan and vegetable natural pigments [22].
2.7.2 Padding System
The padding system is just same as the machines used in continuous dyeing, as
discussed in 1.6.1.4. It essentially consists of a padding process and a drying/fixing
Chapter 2 Pigment Colouration
61
process. Only a few ingredients are needed in a conventional pigment pad bath: the
pigment dispersion, the binder dispersion, the anti-migration agent, the wetting
agent and, for some acrylic binders, ammonia. Occasionally some defoamer may be
used.
Most problems occurring in pigment padding can be attributed to just a few reasons:
the fabric preparation, the mix (mixing procedure, agitation/stirring, straining,
incompatibility), the binder (amount, type, buildup), the pigment (amount, type,
buildup), migration on drying (anti-migrant and equipment), the auxiliary chemicals
and the curing conditions [5].
2.7.3 Exhaust Dyeing System
Exhaust dyeing of pigments is commonly used in garment dyeing and is applied by
using a modified commercial laundry machine. The exhaust system application
mainly consists of four stages: fabric cationization, pigment exhaustion, binder
exhaustion and drying [21].
The overall result is very similar to that achieved when pigment padding fabrics, but
the application methodology is substantially different. Since the pre-treatment and
after-treatment chemicals (the particle fixative and the binder) are proprietary, the
precise mechanism of the process is uncertain [5].
2.7.4 Modification of Pigment Application System
2.7.4.1 Cationization
Cellulose fibres, when immersed in water, exhibit a negative zeta potential and most
of the dye classes suitable for cotton are anionic in nature. Accordingly there is
electrostatic repulsion between cellulose fibres and dye molecules, which results in
Chapter 2 Pigment Colouration
62
low colour yield [32]. Pre-treatment with a cationic fixing agent should improve the
colour strength and fastness due to the changed charge. Chemically cationized
cotton is usually produced by etherification cotton with a tertiary amino or more
often quaternary ammonium cationizing reagents. They can be reacted with cellulose
fibres under a variety of application conditions, such as exhaust, pad-batch,
pad-bake, pad-steam, jig-exhaust, jet-exhaust, etc. [33].
2.7.4.2 Plasma Treatment
Conventional wet pre-treatment processes of textiles are usually energy consuming
processes. Plasma modification of textiles minimises water, chemicals, and electrical
energy. Ecological and economical constrictions which are imposed on the textile
industry, to an increasing extent, encourage the development of environmentally
friendly and economic finishing processes. Large quantities of savings are achievable
since the plasma process does not produce large volumes of waste, effluent or toxic
byproducts [34].
So far, the required surface modification of the fibre is mainly achieved by wet
chemical processes. An appropriate option to conventional techniques is through the
pre-treatment of textile fibres with low temperature glow discharge plasma in air
[34]. The plasma treatment of textiles is attractive because that it is a clean, dry
technology, which dispenses with water or an organic solvent as a processing
medium. In some cases, plasma treatments can impart properties to textiles which
are otherwise unobtainable through wet processes. Plasma treatments of textiles
modify their surface character without affecting their bulk properties. The depth of
the surface treatment is <100nm. The topography of the textile surface is modified,
and its chemical properties may also be altered [27]. Improvements to the textile’s
properties may include increasing fibre wettability, fibre failure stress and strain,
improving shrink resistance and reducing fabric surface resistivity [35, 36]. This
Chapter 2 Pigment Colouration
63
depends on whether greater chemical affinity or inertness has been conferred on the
textile surfaces. Other properties which could be improved are adhesion,
biocompatibility, resistance to wear and tear, rate and depth of dyeing, cleaning of
fibre surfaces, and desizing [27].
The oxidation of the surface of a material, the generation of radicals, and the etching
of the surface are the general reactions which can be achieved by plasma. When
special monomer gases are used, a plasma-induced deposition polymerization may
occur. For the treatment of textiles, this action means that hydrophilization and
hydrophobization may be accomplished; furthermore, both the surface chemistry and
the surface topography could be influenced to result in improved adhesion or
repellency properties as well as the introduction of functional groups to the surface.
Plasma treatment has to be controlled carefully to minimise the damaging action of
the plasma onto the substrate [37].
Two main approaches of plasma treatments applied to the surface modification of
textiles are depositing or non-depositing plasmas. With the depositing plasmas, the
plasma is generally applied by using saturated and unsaturated gases such as fluoro-
and hydro-carbons or vapours (monomers) such as acetone, methanol, allylamine and
acrylic acid. Several reactive etching (Ar, He, O2, N2, F2) or non-polymerisable gases
(H2O, NH3) are utilised in the non-depositing plasmas [38].
Many studies on plasma surface modification of cotton have been undertaken, using
glow-discharge technology at low pressure as well as barrier discharge and corona
treatments at atmospheric pressure. In both conditions, active particles such as
radicals, ions, electrons and photons are generated. When they are under reduced
pressure, these particles have a much larger free path length as compared with the
process at atmospheric pressure. Subsequently, the treatment at atmospheric pressure
Chapter 2 Pigment Colouration
64
generally occurs in a narrow slit, while the treatment at low pressure is performed in a
reactor with a volume adapted to the size of the samples [39, 40].
Research on air and oxygen plasma treatments of cotton fibres have been studied for
many years, with parameters such as discharge power, treatment time and nature and
flow rate of the gas investigated. The chemical effect of the treatments on the cotton
fibres was evaluated via a range of different methods. In many experiments, it was
found that the plasma treatments resulted in surface erosion of the cotton fibres, which
caused a weight loss, accompanied by an increase in carboxyl group and carbonyl
group contents. The growth in carboxyl group concentration led to a more wettable
fibre and the increase of the rate of fabric vertical wicking. It was also shown that the
fabric yellowness is greater with the increase of treatment time. Several studies have
proved that exposure of the cotton fibres to fluorinated gas plasmas leads to a
decrease of water absorption or wettability. Fluorocarbon gas plasmas can modify
surface properties by means of either surface treatment or polymerisation and
deposition of a thin film [39, 41, 42].
2.7.4.3 Fluorocarbon Treatment of dyed fabrics
Fluorochemicals are defined as a man-made, organic fluorine containing compounds
in which most hydrogen atoms are replaced with fluorine. The first syntheses of
fluorochemicals, which are extremely chemically reactive, were conducted in 1886
by Moisson, who harnessed the most electronegative element in nature. The
electrons in fluorine atom are held close to the nucleus with the chemical bond
length between fluorine and carbon being relatively short, which causes the
chemical structure of fluorocarbons to be very compact. Therefore, in perfluorinated
carbon systems, the small fluorine atoms will cover and impart a shielding action to
the carbon-carbon bond [37].
Chapter 2 Pigment Colouration
65
The shielding action has an immense impact on the unique properties of
fluorocarbons and especially of perfluorinated carbon systems. Fluorochemical
products offer some advantageous properties, such as high thermal stability, high
chemical stability, insolubility, and extremely low surface tension. Hence, the use of
fluorochemicals is not limited only to the applications of textile materials, but also
spreads to many other diverse fields. They offer great benefit as a protective agent
against water, stain, and soil for leather, carpet, and paper [37].
A variety of fluorocarbon compounds and polymers can be used to achieve water as
well as oil and stain repellent effects on textiles. If only water repellency is required,
fluorocarbon chain lengths as short as two are adequate [14]. The repellency of
fluorocarbon finishes depends on the structures of the fluorocarbon section, the
non-fluororinated section of the molecule, the orientation of the fluorocarbon tail,
the distribution and the amount of the fluorocarbon moiety on fibres, and the
composition and geometry of the fabric [43].
The fluorochemicals are normally applied by standard finishing processes and
application and must be uniformly distributed so that they penetrate well into the
fabrics. They are applicable both as emulsion and solvent-based solutions. The most
widely used emulsions for fabrics and carpets are of the cationic type, while solvent
solutions are less common. Chemical additives, such as softeners, builders, flame
retardants, or chemical agents for static and bacteria control, could be added in
fabric treating processes. The co-application of these chemicals may have some
influence on final performance properties of the fluorochemical. One typical
example is that there should be no silicones on fabrics or carpets prior to the
fluorochemical treatment because traces of silicone can eliminate the oil repellent
characteristics of the treated fabrics. Silicones can dissolve in oil and reduce the
surface tension of treated fabrics, therefore allowing the oil to adhere to the fabric
Chapter 2 Pigment Colouration
66
[37].
There are three methods to treat the fabric by using fluorochemical products:
conventional padding, spraying, and foam application. Before the fluorochemical
treatment, it is necessary to ensure that the fabric is clean and its pH range is 5-7.
Every application method has the same post-processes involving drying and heat
curing operations. All aqueous fluorochemical-based finishes are required to be
oriented correctly in order to form an efficient repellent surface and produce the
bonding of chemical agents on fabrics. The drying process should be immediately
followed after chemical treating by exposing the treated samples to an elevated
temperature and typical drying machines are the forced-air oven type. Curing is
usually performed at 150-190℃, for a period of 2-10 minutes [37].
There are many diverse applications for fluorocarbons due to their versatility.
Because of their outstanding chemical and thermal stability, they can be used as
durable lubricants, corrosion protective coatings for metals, non-flammable plastics,
and fluorine elastomers in the rubber industry and as heat transfer fluids in
refrigeration technology. As a benefit of their non-miscibility, fluorocarbons are
treated as substitution products, and as protective agents against water, oil and soil in
the paper, leather and textile industries. Due to their effective wetting capacity, they
can be applied as fire fighting agents and wetting agents in electro-plating,
electronics and textile industries [44, 45].
2.8 Advantages and Disadvantages of Pigment Colouration
The advantages are:
Pigment colouration is the simplest colouring process as it just consists of
printing/dyeing, drying and fixation. Therefore it is a very economical process,
due to the elimination of all wet after-treatments;
Chapter 2 Pigment Colouration
67
The pigment technique can be applied to most substrates, including glass fibre,
imitation synthetic leather and PVC, at light to medium depth;
The spectral range of pigments is extensive, and the colours are bright;
Pigment printing presents the fewest problems for the printer in printing various
fabric blends;
Some special colouration effects can only be achieved using pigments. Also
pigment colouration can greatly decrease the influence of background colour,
such as printing a white pattern on deep shade fabric;
Good light fastness and colour fastness properties can be achieved with the
appropriate print/dyeing formulation;
In the colouration process, pigmentation offers lower labour and equipment
demands while keeping high production reliability;
If pigments are over-printed, the lower layer has almost no effect and the top
layer determines the colour [1, 5].
The disadvantages are:
The application of chemicals, like binders and crosslinkers can cause increased
stiffness and present handle issues;
The colour fastness, especially the wet rub fastness is poor. For medium or deep
shade pigment coloured fabric, which is made from polyester, wool or acrylic
fibres, the degree of colour fastness is ideally only suitable for products that will
not be subjected to a great quality of wear;
Although pigmented samples resist a certain degree of dry cleaning, the
problem of fading after cleaning is still present [1, 5].
2.9 Aims and Objectives of Research
The current research work was undertaken keeping in mind the growing interest in
environmentally friendly textile colouration. As the simplest colouring process
Chapter 2 Pigment Colouration
68
pigment colouration just consists of printing/dyeing, drying and fixation. Therefore it
is a very economical and environmentally friendly process, due to the elimination of
all wet after-treatments. There have been many studies in pigment printing area while
the use of pigment dyeing becomes increasingly popular recently due to the concern
of environmental and energy problems. This study aimed at modifying the pigment
dyeing system with a view to improving fastness, in particular improving the wet rub
fastness.
Chapter three details the methodology and standards that were followed in undertaking
the processing research and the subsequent characterisation. Chapter four discusses the
performance of Matrix OSD pigment dyeing system and the standard dyeing system
for this study was chosen. Chapter five deals with the cotton fabric surface
modification and the incorporation of crosslinkers into the binder formulation. The
cationization reagent and ultraviolet/ozone were pretreated on cotton fabrics to
improve the dyeability. Chapter six describes the fluorocarbon treatment in the
pigment dyeing system including plasma polymerized fluorocarbon treatment.
Chapter seven discussed the effects of plasma polymerisation treatments before and
after pigment dyeing. Scanning Electron Microscopy (SEM) analysis was used to
study the changes in the surface morphology of the pigment dyed cotton fibres,
especially for samples before and after rubbing. In addition X-ray Photoelectron
Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry
(ToF-SIMS) analysis allowed the surface chemistry of the pigment dyed cotton
fabrics to be probed in Chapter eight.
2.10 References
1. Miles, L. W. C, Textile Printing. Rev. 2nd edn, 2003, Bradford: Society of
Dyers and Colourists. x, p.339.
Chapter 2 Pigment Colouration
69
2. Kramrisch, B., Pigment Printing and Dyeing of Cotton. American Dyestuff
Reporter, 1986, 75(2): p.13.
3. Humphries, A., Muff, J. R., and Seddon, R., Aqueous System for Pigment
Printing. Colourage, 1985. 32(5): p.15-27.
4. Kass, M., Application of Pigment to Textiles. J. Soc. Dyers Col, 1958.
5. Aspland, J. R., Textile Dyeing and Coloration, 1997, Triangle Park, N.C.:
American Association of Textile Chemists and Colorists. p.410.
6. American Association of Textile Chemists and Colorists. Committee RA80
Printing Technology., Pigment printing handbook, 1995, Research Triangle
Park, N.C.: Committee RA-80 Printing Technology, American Association of
Textile Chemists and Colorists, iii, p.151.
7. Schwindt, W., and Faulhaber, G., The Development of Pigment Printing
Over the Last 50 Years. Review of Progress in Coloration and Related Topics,
1984, 14(1): p.166-175.
8. Printing of Pigments and Special Effects. Cotton Incorporated Technical
Bulletin, 2007, ISP(1017): p.1-14.
9. Denton, M. J., and Daniels, P. N., Textile Terms and Definitions. 11th edn.
2002, Manchester, UK: Textile Institute. ix, p.407.
10. Patton, T. C., Pigment Handbook, 1973, New York,: Wiley.
11. Shore, J., Colorants. 2nd edn. 2002, Bradford: Society of Dyers and
Colourists. ix, p.469.
12. Zollinger, H., Color Chemistry: Syntheses, Properties, and Applications of
Organic Dyes and Pigments. 2nd rev. edn. 1991, Weinheim ; Cambridge:
VCH. xvi, p.496.
13. Christie, R. M., Mather, R. R., and Wardman, R. H., The Chemistry of
Colour Application, 2000, Oxford: Blackwell Science. viii, p.288.
14. Vigo, T. L., Textile Processing and Properties: Preparation, Dyeing,
Finishing and Performance, 1994, Amsterdam ; London: Elsevier. xvii,
Chapter 2 Pigment Colouration
70
p.479.
15. Hao, Z. M. and Iqbal, A., Some Aspects of Organic Pigments. Chemical
Society Reviews, 1997. 26(3): p.203-213.
16. Smith, F. M., An Introduction to Organic Pigments. Journal of the Society of
Dyers and Colourists, 1962, 78(5): p.222-231.
17. Schwarz, S. and Endriss, H., Inorganic Colour Pigments and Effect Pigments
Technical and Environmental Aspects. Review of Progress in Coloration and
Related Topics, 1995, 25(1): p.6-17.
18. Whistenant, J., Pigments in Textile Printing. Pigment Printing Handbook,
1995, p.45.
19. Hammonds, A. G., Introduction to Binders. Pigment Printing Handbook,
1995, p.57.
20. Patel, D. C., Synthetic Binders for Pigment Printing. Textile Printing 1997.
21. Binders for Textile Applications. Cotton Incorporated Technical Bulletin,
2004, ISP(1008): p.1-16.
22. Lacasse, K. and Baumann, W., Textile Chemicals : Environmental Data and
Facts, 2004, Berlin ; London: Springer. xxvi, p.1180.
23. Schindler, W. D. and Hauser, P. J., Chemical finishing of textiles, Cambridge:
Woodhead in association with The Textile Institute ; Boca Raton. x, p.213.
24. Karypidis, M. I., Effect of Softening Agents on the Wear of Textiles, 2000,
PhD Thesis, Manchester: UMIST.
25. Arunyadej, S., Investigation into the Performance of A Fluorocarbon Finish
on Cotton Fabric, 1997, MSc Thesis, UMIST.
26. Anilin, B., Manual: Textile Finishing, 1973, Ludwigshafen: BASF AG.
27. Wei, Q., Surface Modification of Textiles, 2009, Cambridge: Woodhead Pub.
xx, p.337.
28. Shore, J., Colorants and Auxiliaries, Vol 2., 2nd edn. Society of Dyers and
Colourists.
Chapter 2 Pigment Colouration
71
29. Thompson, D., Pigment Printing Auxiliaries. Pigment Printing Handbook,
1995, p.97.
30. Schwindt, W., New Thickening Agents and New Possibilities for Pigment
Printing. Textilveredlung, 1969, 4(9): p.698.
31. Nettles, J. E., Handbook of Chemical Specialties: Textile Fiber Processing,
Preparation, and Bleaching, 1983, New York: Wiley. xviii, p.467.
32. Fang, K. J., Pigment Dyeing of Polyamide-Epichlorohydrin Cationized
Cotton Fabrics. Journal of Applied Polymer Science, 2010, 118(5):
p.2736-2742.
33. Wang, L. L., Preparation of Cationic Cotton with Two-bath Pad-bake Process
and Its Application in Salt-free Dyeing. Carbohydrate Polymers, 2009, 78(3):
p.602-608.
34. Karmakar, S. R., Chemical Technology in the Pre-treatment Processes of
Textiles, 1999, Amsterdam.
35. Cook, J. G., Handbook of Textile Fibres: By J. Gordon Cook, 1968: Merrow
Publishing Company.
36. McIntyre, J., Synthetic Fibres: Nylon, Polyester, Acrylic, Polyolefin, 2005,
CRC Press.
37. Arunyadej, S., Investigation into the Performance of A Flurocarbon Finish on
Cotton Fabric, 1997, MSc Thesis, Manchester: UMIST.
38. Drumright, R. E., Gruber, P. R., and D. E. Henton, Polylactic Acid
Technology. Advanced Materials, 2000, 12(23): p.1841-1846.
39. Shishoo, R., Plasma Technologies for Textiles, 2007, Cambridge: Woodhead
Pub.
40. Hua, Z., Mechanisms of Oxygen- and Argon-RF-plasma-induced Surface
Chemistry of Cellulose. Plasmas and Polymers, 1997, 2(3): p.199-224.
41. Özdogan, E., A New Approach for Dyeability of Cotton Fabrics by Different
Plasma Polymerisation Methods. Coloration Technology, 2002, 118(3):
Chapter 2 Pigment Colouration
72
p.100-103.
42. Malek, R. M. A. and Holme, I., The Effect of Plasma Treatment on Some
Properties of Cotton. Iranian Polymer Journal, 2003, 12(4): p.271-280.
43. Lewin, M. E. and Sello, S. B., Handbook of Fiber Science and Technology,
1984, New York: M. Dekker.
44. Grayson, M. E. and Eckroth, D. E., Encyclopedia of Chemical Technology,
Index to Volumes 1-24 and Supplement. 3rd edn . 1984, John Wiley & Sons.
45. Shekarriz, S., An Investigation into the Modification of Cotton Fibres to
Improve Crease Resist and Repellency Properties, 1999, PhD Thesis,
UMIST.
Chapter 3 Instrumental Techniques
73
Chapter 3 Instrumental Techniques
3.1 Introduction
This chapter discusses the methodology and standards which were followed in
undertaking the processing research and the subsequent characterisation. In this study
dyed fabrics were analysed in terms of colour fastness, colour strength, “handle”,
surface analysis (X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight
Secondary Ion Mass Spectrometry (ToF-SIMS)) and appearance (Scanning Electron
Microscopy (SEM). There are various standards available for the testing of textiles, such
as ISO (International Standards Organization), AATCC (American Association of
Textile Chemists and Colorists) and B.S. (British Standards).
3.2 Physical Testing
3.2.1 Colour fastness
The definition of colour fastness, proposed by the American Association of Textile
Chemists and Colourists, is as follows: ‘The resistance of a material to change in
any of its colour characteristic, to transfer its colourants to adjacent materials, or
both, as a result of the exposure of the material to any environment that might be
encountered during the processing, testing, storage, or use of the material’ [1].
Colour changes of the test specimen and staining of undyed adjacent fabrics are two
aspects of the colour fastness assessment. There are two standard grey scales used to
assess change, colour change grey scales and the degree of cross-staining grey scales
[2].
Chapter 3 Instrumental Techniques
74
3.2.1.1 Rub fastness
In this study, Rub fastness of the cotton fabric was performed in accordance with
ISO 105-X16: 2002 standard. The AATCC crockmeter, Figure 3.1, was used as the
rubbing fastness tester. Prior to testing, the crock squares and specimens were
conditioned for at least 24 hours in an atmosphere of 21±1℃ and 65±2% RH. The
specimen was then placed on the base of the crockmeter resting flat and the crock
square covered the end of the finger as presented in Figure 3.1. For the wet rub
fastness, the crock squares need to be wetted at a wet pick-up about 65±5%. The
finger was lowered onto the test specimen and moved 10 complete turns. The white
crock squares were evaluated in comparison to the Grey Scale for Staining, shown in
Figure 3.2. The dry and wet rub fastness was rated at 9 levels: 5, 4/5, 4, 3/4, 3, 2/3, 2,
1/2, 1 [3].
Figure 3.1 AATCC crockmeter
Chapter 3 Instrumental Techniques
75
Figure 3.2 Grey scale assessment for staining
3.2.1.2 Wash fastness
The fastness to laundering of pigment dyed fabrics was determined according to the
ISO 105-C06: 2002 test method. A fabric sample, 100±2mm x 40±2mm, was stapled
to a piece of the same size multifibre adjacent fabric.
The wash liquor was prepared by dissolving 4 g/L of SDC ECE detergent (phosphate
based) and 1 g/L sodium perborate tetrahydrate in 1 litre distilled water and stirred at
60°C. There was 50mls of detergent solution and 25 steel balls added in each steel
container. The Roaches Washtec P machine was set at 60°C for 30 minutes. The
samples were then removed, rinsed in distilled water and air-dried. The change in
colour of the specimen and the staining of the adjacent fabric were assessed using the
Grey Scale for Staining and the Grey Scale for Colour Changing, Figure 3.3. The
wash fastness was rated at 9 levels similar to the rub fastness testing [4].
Chapter 3 Instrumental Techniques
76
Figure 3.3 Grey scale for assessing colour change
3.2.2 Colour Strength
The strength of colourant can be measured in terms of the Kubelka-Munk (K/S)
value which has been derived from the Kubelka-Munk function (R) [5].
K/Sλ =(1 − R∞)
2
2R∞
Where R∞ = reflectance of light of a particular wavelength from a sample of infinite
thickness. Colour strength by a single wavelength method was measured at a
specified wavelength (λ) of maximum absorption using the above equation where K
is the absorption coefficient and S is scattering coefficient. Reflection of the samples
was measured from 400-700nm at intervals of 20nm [5]. In this study by measuring
reflectance (R) with a DataColor 500i spectrophotometer, K/S can be determined.
The samples (folded four times) were held on the spectrophotometer measuring port.
The spectrophotometer was calibrated under white, black and green standards with
the following settings: USVP, 10˚Standard Observer, UV/Specular excluded.
Chapter 3 Instrumental Techniques
77
3.2.3 Martindale Abrasion Test
The Martindale abrasion test was performed according to BS 569091:1991. The
standard crossbred worsted abradant material used in the test was replaced at the
beginning of each new test. The samples to be tested were conditioned in a standard
atmosphere, with a relative humidity of 65±2% R.H. and a temperature of 20±2℃,
for at least 24 hours before testing. For each sample, four circular pieces were cut
with a 38 mm diameter using a press cutter. Each individual piece was mounted in a
sample holder on the abrasion machine with a circular 38 mm diameter piece of
polyurethane foam and placed behind the sample as backing. Each of the sample
holders was fastened on the moving plate under a load of 12 kPa and fabrics were
abraded under a cyclic planar motion. Samples were examined at suitable intervals,
shown in Table 3.1, using a low power stereomicroscope to ascertain whether two
yarns were broken while sample pieces were still on sample holders. The mean
values of the rubs for the four pieces of each fabric were not recorded until the
second yarn breakdown [6].
Table 3.1 Test intervals for abrasion testing
Test series
Number of rubs (N) at
which specimen
breakdown occurs
Test interval
(rubs)
A N ≤ 5000 Every 1000
B 5000 < N ≤ 20000 Every 2000
C 20000 < N ≤ 40000 Every 5000
D N > 40000 Every 10000
3.2.4 KES-F System
Fabric handle is a subjective judgement for each person according to touch and feel.
There are descriptive adjectives and hand feeling terms, such as smooth, rough, stiff,
Chapter 3 Instrumental Techniques
78
soft and so on, used to describe this assessment [2, 7]. So, it is generally agreed that
the subjective assessment of handle is the transmission of information from finger
stimuli to human perception. Before the Kawabata system, fabric handle was
evaluated by skilled experts who had training to judge the quality with their hands,
but with the average consumer the results vary from person to person and
predictability and sensitivity were accordingly more variable.
The Kawabata Evaluation System (KES) measures the fabric’s mechanical and
surface properties at low load levels typical of normal handling and end-user
applications. The system has been used to predict performance in garment
manufacture and to develop optimal finishing routines in order to maximise the
quality of the final garment fabric.
In this research, the 20 x 20 cm fabrics were conditioned for 24 hours at 20ºC and 65%
R.H. prior to testing. The selected KES-F shear and bending mechanical property
values presented were the average of five measurements. However the full set of
KES parameters that can be measured are listed in Table 3.2.
Chapter 3 Instrumental Techniques
79
Table 3.2 Parameters measured in the Kawabata Evaluation System
Parameter Symbol Units
Tensile Properties
Extensibility EM %
Linearity of Load-Extension Curve LT -
Tensile Energy WT g.cm/cm2
Tensile Resilience RT %
Bending Properties
Bending Stiffness B g.cm2/cm
Bending Hysteresis 2HB g.cm/cm
Shear Properties
Shear Stiffness G g/cm.deg
Shear Hysteresis at 0.5o 2HG g/cm
Shear Hysteresis at 5o 2HG5 g/cm
Surface Properties
Coefficient of Friction MIU -
Mean Variation of MIU MMD -
Geometrical Roughness SMD μm
Compression Properties
Linearity of Pressure-Thickness curve LC -
Compression Energy WC g.cm/cm2
Compression Resilience RC %
Miscellaneous
Thickness T mm
Weight W mg/cm2
Chapter 3 Instrumental Techniques
80
Bending stiffness (B) relates to the ability of a fabric to be distorted by bending. It is
generally a function of fabric weight and thickness but can also reflect the effect of
chemical processing and/or finishing routines. Bending stiffness is particularly
important in the tailoring area for lightweight fabrics. It is difficult to sew a very
supple fabric which means that its bending stiffness is low, whereas a firm fabric can
be more manageable in sewing and offer a flat seam. However, lower bending
stiffness provides a higher total hand value and better flexibility/drapability.
Shear properties in association with bending stiffness can provide an indication of
the fabric drapability. Assessment of this property gives a measure of the resistance
to rotating movement of warp and weft yarns within a fabric. Certain chemical
treatments like the application of fabric softeners can moderate the fabric shear
stiffness property by lubricating the yarns and reducing the inter-yarn friction. They
are measured with a maximum shear angle of ±8˚. Lower values of shear stiffness
(G) would cause more difficulty in laying and handling because of the fabric
distortion and garment appearance would be worse. Shear hysteresis at 5˚ shear
angle (2HG5) is the measurement of energy loss during shear deformation. Mostly
this energy loss is caused by inter-yarn friction at crossing points. Higher shear
hysteresis indicates that more recovery forces would be required to overcome fabric
internal friction. Smaller 2HG5 values impart comfort, softness, drape, and garment
appearance. However, too low 2HG5 values could cause a reduction in fabric
sewability due to fabric high elastic behaviour in shear distortion [8].
3.2.5 Oil and Water Repellency Measurements
Several test methods are available to measure fabric wetting resistance to selected
liquids. In this study, the 3M oil and water repellency tests were chosen because of
the portability and simplicity of the instrumentation and test procedure. It is
applicable to any fabrics which are with or without a liquid resistant or liquid
Chapter 3 Instrumental Techniques
81
repellent treatment [9].
In 3M test, the degree of water repellency ranges from W to 10W, while the degree
of oil repellency ranges from 1 to 8. If totally without repellency, it is marked
‘failed’. The liquids used in the water repellency test include water, water/isopropyl
alcohol mixtures and isopropyl alcohol. In oil repellency testing, the test liquids are
liquid-phase paraffin, n-hexadecane, n-dodecane, n-decane, n-octane, and n-heptane.
Different test liquids offer varying degrees of repellency and associated surface
tension as shown in Tables 3.3 and 3.4 [9].
Table 3.3 Range of test liquids with decreasing surface tension for the oil-repellency
test [10]
Oil-Repellency Test Liquid Surface Tension
(mNm-1
at 25℃)
1 Nujol oil 31.2
2 65/35 nujol/n-hexadecane 28.7
3 n-hexadecane 27.1
4 n-tetradecane 26.1
5 n-dodecane 25.1
6 n-decane 23.5
7 n-octane 21.3
8 n-heptane 19.6
Table 3.4 Range of test liquids employed with decreasing surface tension [11]
Test Liquid Composition of Test Liquid %
W 100 Water
W1 90/10 Water/Isopropyl Alcohol
W2 80/20 Water/Isopropyl Alcohol
W3 70/30 Water/Isopropyl Alcohol
W4 60/40 Water/Isopropyl Alcohol
W5 50/50 Water/Isopropyl Alcohol
W6 40/60 Water/Isopropyl Alcohol
W7 30/70 Water/Isopropyl Alcohol
W8 20/80 Water/Isopropyl Alcohol
W9 10/90 Water/Isopropyl Alcohol
W10 100 Isopropyl Alcohol
Chapter 3 Instrumental Techniques
82
According to the 3M test procedure, a drop of test liquids is placed on several
locations of the fabric surface. Then the observations of wetting and contact angle
are made. The degree of water and oil repellency is determined, after the observation
period of 10 seconds for water repellency and 30 seconds for oil repellency, by
recording the highest numbered test liquid which does not wet the fabric surface [6].
3.3 Analytical Methods
3.3.1 Scanning Electron Microscopy (SEM)
The scanning electron microscope images the specimen’s surface by focusing an
electron beam onto the materials surface and collecting the reflected electrons from
the surface to form an image. It can achieve high magnification with excellent depth
of focus coupled to a simple sample preparation operation. Since most textile fibres
are usually non-conductive they have to be coated with a thin conducting film to
reduce the probability of ‘charging’ effect. Normally a 2 – 20nm coating should be
carefully applied, since an extremely thick coating may hide surface details [12].
Scanning Electron Microscopy is based on the interaction between a beam of
electrons and the solid surface onto which it collides. Figure 3.4 shows a simplified
schematic diagram of an SEM [13].
The electron gun is a thin, pointed filament of wire, which is electrically heated and
then emits electrons from its tip which are collected and focused. The energy and
direction of these electrons are controlled by the applied voltage between the filament
(forming the cathode) and an annular metal plate (the anode) which is placed under
the filament [13]. When the high-energy electron beam impinges the surface of fabrics,
a range of interactions occur leading to particle or radiation emissions. The image
Chapter 3 Instrumental Techniques
83
detector collects the backscattered and low-energy (secondary) electrons in forming
the image [12].
Figure 3.4 Schematic of a typical SEM [13]
In this study, a Hitachi S-3000N Scanning Electron Microscope was used and after
attaching the samples on the sample holder, a gold coating was applied using a Gold
Sputter-Etch unit. The SEM analysis was performed with working voltage 5kV, a
working distance around 9.5mm and a magnification of 2000 times.
3.3.2 X-ray Photoelectron Spectroscopy (XPS)
Of all the surface chemical analysis techniques, X-ray photoelectron spectroscopy
(XPS) is the most widely used characterization tool. XPS can be also called Electron
Spectroscopy for Chemical Analysis (ESCA) [14]. The breadth of obtained
information and its flexibility in examining a wide range of materials are the reasons
why XPS is popular as a surface analysis technique [15]. The XPS technique
involves bombarding the surface with X-rays and determining the binding energy
Chapter 3 Instrumental Techniques
84
(BE) of the emitted photoelectrons ejected from the outer depth 3-5nm of the tested
sample. The photoelectron BE value allows the emitting atom to be identified and its
oxidation state and chemical environment established. Quantitative information
about the elements can be also provided by XPS technique.
XP spectra were obtained from a Kratos Axis spectrometer. The textile samples were
attached on the spectrometer probe with double sided adhesive tape and analysed
with Al Kα radiation (1486.6eV). The spectrometer pressure was 4x10-8
torr. Wide
survey spectra were recorded at a pass energy of 100eV in order to determine the
surface chemical composition. High resolution spectra were recorded with a pass
energy of 20eV and all BE values were calculated in relation to the C(1s)
photoelectron peak at 285.0eV [6]. Charge compensation for the samples was
achieved using a 4–7eV beam at a flood current of ~0.1 mA, with an electrically
ground 90% transmission nickel mesh screen. All samples were analyzed in
duplicate and the data was analyzed using CASA XPS software.
The XPS spectrum contains peaks, which can be associated with the various
elements (except H and He) present in the outer 3-5 nm of the tested fabric. The
amount of each element is related to the area under these spectral peaks. Therefore,
the atomic compositions of each element detected can be determined by measuring
the peak areas and correcting using the photo-ionisation cross-section values [16].
3.3.3 Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS)
ToF-SIMS is a technique which can analyse surface chemistry with great precision
and sensitivity and is particularly useful for characterising organic species at
surfaces. In operation, the surface of a sample is bombarded by energetic particles,
usually ions, and the masses of the sputtered secondary ions from the surface are
characterised accordingly [17]. Both molecular and elemental details can be
Chapter 3 Instrumental Techniques
85
provided. In addition, ToF-SIMS offers better surface sensitivity for fabric samples
with a sampling depth is approximately 1-2nm, while that of XPS is approximately
3-10nm [18]. The high mass resolution is a characteristic of ToF-SIMS, which
allows accurate mass analysis for clear identification of empirical formulae of
unknown materials.
In this research, pigment dyed, fluorocarbon treated, washed and washed and heat
pressed samples were analysed by CERAM, Stoke, UK. The operation involves
sputtering the sample with a pulsed beam of bismuth primary ions (Bin+ where n =
1-3). Elemental and molecular fragment ions formed at the surface were
mass-analysed and mass spectra were obtained. Positive and negative ion spectra
were acquired from an area of ~500µm x 500µm in the mass range 0-2000.
3.4 References
1. Colorfastness of Cotton Textiles. Cotton Incorporated Technical Bulletin,
2002.
2. Saville, B. P., Physical Testing of Textiles, 1999, Cambridge, England:
Woodhead Publishing.
3. Rivlin, J., The Dyeing of Textile Fibers: Theory and Practice, 1992,
Philadelphia: J. Rivlin. xiii, p.220.
4. British Standards Institution, Textiles. Tests for Colour Fastness. Colour
Fastness to Domestic and Commercial Laundering, 2010, BSI.
5. Tayyebkhan, A., Colour Physics, 1996, Oil and Colour Chemists
Association.
6. Shekarriz, S., An Investigation into the Modification of Cotton Fibres to
Improve Crease Resist and Repellency Properties, PhD Thesis, 1999,
UMIST.
Chapter 3 Instrumental Techniques
86
7. Collier, B. J. and Epps, H. H., Textile Testing and Analysis, 1998, Upper
Saddle River, NJ: Prentice Hall. xx, p.374.
8. Dhariwal, J., An Investigation into the Effect of Pigment Printing on Fabric
Handle, 1996, Manchester: UMIST.
9. Carr, C. M., Chemistry of the Textiles Industry, 1995, London: Blackie
Academic & Professional. xiii, p.361.
10. Data, M. T., Test Method - Water Repellency Test II - Water/Alcohol Drop
Test, 1996.
11. Data, M. T., Test Methods - Oil Repellency I, 1996.
12. Greaves, P. H., Saville, B. P., and Royal Microscopical Society (Great
Britain), Microscopy of Textile Fibres. Microscopy Handbooks, 1995,
Oxford: BIOS Scientific in association with the Royal Microscopical Society.
xii, p.92.
13. Love, U. P. G., Scanning Electron Microscopy, in Centre for Electron Optical
Studies, 1999, University of Bath: UK. p.10.
14. Vigo, T. L., Textile Processing and Properties: Preparation, Dyeing,
Finishing, and Performance. Textile science and technology, 1994,
Amsterdam Netherlands ; New York: Elsevier. xvii, p.479.
15. Zeng, F., Investigation into the Colouration of Polypropylene, 2002, PhD
Thesis, UMIST.
16. Özdogan, E., A New Approach for Dyeability of Cotton Fabrics by Different
Plasma Polymerisation Methods. Coloration Technology, 2002, 118(3):
p.100-103.
17. Vickerman, J. C. and Briggs, D., ToF-SIMS: Surface Analysis by Mass
Spectrometry, 2001, Chichester: IM; Manchester: SurfaceSpectra.
18. Höcker, H., Plasma Treatment of Textile Fibers. Pure and Applied Chemistry,
2002. 74(3): p.423-427.
Chapter 4 Investigation of Basic Binder System
87
Chapter 4 Investigation of Basic Binder
System
4.1 Introduction
As discussed in 2.4, the binder plays an important role as a key element in the
performance of the pigment colouration. It affects colour fastness, fabric handle, and
colour strength [1]. Thus, before providing further insight into pigment colouration,
it is necessary to first elaborate on the binder system. As the earliest textile printing
method, pigment printing is the most important technology which has been applied
for many years. There have been many investigations in this area but with the use of
pigment dyeing becoming increasingly popular recently due to the concern of
environmental and energy problems papers in this area have also appeared [2-7].
Therefore in order to reduce wastage and contribute to cost-effectiveness, pigment
dyeing may become one of the best choices for textile dyeing. The main limitation
of pigment colouration, however, is the relatively poorer colour performance, in
particular the low wet rub fastness and harsher handle [8-10].
This study investigates pigment dyeing and specifically two types of binders, Matrix
OSD and Matrix OSD without softener, manufactured by Beyond Surface
Technologies. Matrix OSD is a formulation containing a silicone-based softener and
binder. Matrix OSD is the only binder used in this research as it is specifically
marketed as offering environmentally beneficial performance. Also Matrix OSD
without softener was assessed due to potential non-compatibility with fluorocarbon
treatments, Chapter 6, and in order to assess the effect of the softener on the binder
properties. According to the supporting company information for Matrix OSD, it can
be used together with most products commonly encountered in high-grade finishing.
Thus it is suitable for the pre- or after-treatment of fabrics.
Chapter 4 Investigation of Basic Binder System
88
Mercerized and bleached cotton fabric was used in the initial studies and bleached
cotton fabric was used subsequently. Mercerization involves the modification of
cotton yarn or fabric by swelling when immersed in a concentrated aqueous solution
of caustic soda [11, 12]. In theory, the beneficial effects of cotton mercerization
include: increased tensile strength, softness, lustre (if mercerized under tension),
improved affinity for dyes, dyeability of immature fibres and higher water sorption
[11].
4.2 Experimental
4.2.1 Materials
Fabrics 100% bleached, mercerized plain weave cotton fabric, 135g/m2,
was supplied by Phoenix Calico, Stockport.
100% bleached plain woven cotton fabric, 191.5g/m2, was also
supplied by Whaleys, UK.
Pigments Helizarin EE-BBT was supplied by BASF, UK.
Lyosperse red 2BN LIQ and Lyosperse yellow MR LIQ were
supplied by Huntsman, UK.
Neoprint Green-LBS, Black-LBAC and Blue-LBS were supplied
by Beyond Surface Technologies, Switzerland.
Minerprint Blue B was supplied by Quality Colours, UK.
Binders Matrix OSD was supplied by Beyond Surface Technologies,
Switzerland.
Matrix OSD, without softener, was supplied by Beyond Surface
Technologies, Switzerland.
Wetting agent Alcopol 070 was supplied by Huntsman, UK.
Chapter 4 Investigation of Basic Binder System
89
4.2.2 Dyeing System
Distribution of the pigment over the “wettable” textile during pigment dyeing is first
and foremost a function of the application machine technology. In this study, the
padding system was chosen as the main application system. Normally, pigment
dyeing is performed in several steps, in particular the three stages are: pad bath
preparation; padding; drying and curing [13].
A 2-roll horizontal padder, Werner Mathis HF, was used throughout the study with the
wet pick up controlled by pneumatic pressure transmission at the nip. The pigment
dyeing solution filled the nip through which the fabrics passed during immersion and
subsequent squeezing. The fabric was evenly padded to avoid non-uniformity, with
the padding speed and wet pick up being 2m/minute and 80%, respectively.
The Benz stenter, JT/M 500, was used for thermal treatments of textile materials
throughout the study. It can be used for drying and stabilizing surface materials, fixing
of dyes, and offers the possibility of continuous processes with pre-padding on the
padder. The samples were pinned on the frame evenly and the process of drying
controlled, in case of the migration of pigment solution introducing non-uniformity.
For the pigment dyeing system, the temperature is 110℃ for 3 minutes in the drying
process and 180℃ for 1 minute during the fixation period.
4.2.3 Matrix OSD System
The 100ml stock formulation consisted of 90mls Matrix OSD binder and 10mls
pigment colourant. Five different stock formulations were made containing the red,
yellow, black, blue and green pigments. For each colour, three different
concentrations were prepared contained 10g/L, 50g/L and 100g/L stock formulation,
Chapter 4 Investigation of Basic Binder System
90
listed in Table 4.1. The cotton fabrics were padded at 80% wet pick up (w.p.u.), then
dried at 110℃ for 3 minutes, and cured 1 minute at 180℃.
Table 4.1 Concentration of stock formulations
Red Yellow Blue
Formulation Conc. g/L 10 50 100 10 50 100 10 50 100
Black Green
Formulation Conc. g/L 10 50 100 10 50 100
4.2.4 Modified Matrix OSD System
Following the preliminary studies in 4.2.3 the Matrix OSD 100ml stock formulation
consisting of 90ml Matrix OSD and 10ml pigment colourant was prepared using the
red, yellow and blue pigments at 10g/L, 100g/L and 150g/L, representing light,
medium and heavy shades, Table 4.2. In the dyeing solution, 1g/L wetting agent was
added to improve the wettability of fabrics. Three different fabrics were treated
using this formulation set, cotton, poly/cotton (55/45) and polyester (PET). They
were padded twice at 80% wet pick up (w.p.u.), then dried at 110℃ for 3 minutes,
and cured 1 minute at 180℃.
Table 4.2 Concentration of stock formulation
Red Yellow Blue
Formulation Conc. g/L 10 100 150 10 100 150 10 100 150
4.2.5 Matrix OSD without Softener
The formulation composition was the same as the modified Matrix OSD system, the
only difference being the use of the binder, which does not contain any silicone
softener. The application process and formulation concentration was exactly the
same as in the modified matrix OSD system.
Chapter 4 Investigation of Basic Binder System
91
4.3 Results and Discussion
4.3.1 Matrix OSD System
The main indicators of the performance of the binder/colourant system, the rub
fastness, wash fastness, colour strength and fabric handle were tested for the Matrix
OSD system. From the results presented in Table 4.3, it can be seen that the different
pigment colourants in each concentration level show the similar fastness results
except wet rub fastness. It is apparent that wash fastness and dry rub fastness remain
at a high level, whereas wet rub fastness was relatively poorer. Interestingly, the
results of lighter colours are visible better than those of darker coloured fabrics,
indicating wet rub fastness performance was affected by the depth of colour. The
colour strength (Table 4.4) of the dyed fabrics increased with the higher levels of
stock formulation concentration.
Figures 4.1-4.3 show the effect of varying the concentration of formulation applied
to cotton fabric on bending stiffness, shear stiffness and shear hysteresis,
respectively, indicating that the bending stiffness increased as the stock formulation
concentration was raised. The handle properties of the fabric samples with lighter
colours were in general “softer” than those the heavier shades, with the trends for
each colour similar. The bending stiffness of the plain cotton fabric was higher than
the 10g/L dyed samples. This was caused by the “relaxing” aqueous treatment and
the softener in the binder formulation at low application levels reducing the
stiffening action of the binder. The shear stiffness shows the same trend as bending
stiffness although again the increases were relatively small. The shear stiffness of
the untreated cotton was lower than those fabrics with concentrations of 50g/L and
100g/L, but higher than those fabrics treated with 10g/L formulation. Examination
of the shear hysteresis at 5o values indicated variable behaviour with any increases
in interyarn surprisingly small. 2HG5 has been identified as the KES-F parameter
Chapter 4 Investigation of Basic Binder System
92
most sensitive to fabric softness with any lubrication by softeners of fibre surfaces
being reflected in lower interyarn friction.
Table 4.3 Effect of varying the concentration of the formulation applied to cotton
fabric on the wet/dry rub fastness
Formulation
Conc. g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow
10 4/5 4 5 5
50 5 3 5 5
100 5 3 4/5 5
Red
10 5 4 5 5
50 4/5 3/4 5 5
100 4/5 3 4/5 5
Green
10 4/5 3 4/5 5
50 4/5 2/3 4/5 5
100 4/5 2/3 5 5
Blue
10 4/5 3 4/5 5
50 4 2/3 5 5
100 4 2/3 5 5
Black
10 5 3/4 4/5 5
50 4 2/3 4/5 5
100 4/5 2/3 4/5 5
Table 4.4 Effect of varying the concentration of the formulation applied to cotton
fabric on the colour strength
Formulation Conc. g/L λmax (nm) (K/S) λmax
Yellow
10 430 0.87
50 440 3.81
100 440 6.31
Red
10 570 0.56
50 570 2.31
100 570 4.4
Green
10 640 0.67
50 640 2.86
100 640 5.35
Blue
10 610 0.88
50 610 3.05
100 610 5.26
Black
10 400 0.95
50 400 2.92
100 400 5.08
Chapter 4 Investigation of Basic Binder System
93
0 10 20 30 40 50 60 70 80 90 100 110
0.15
0.20
0.25
0.30
0.35
Ben
din
g S
tiff
nes
s (g
.cm
2/c
m)
Formulation Conc. (g/l)
Red
Yellow
Blue
Green
Black
Figure 4.1 Effect of varying the concentration of the formulation applied to cotton
fabric on the KES-F bending stiffness, B
0 10 20 30 40 50 60 70 80 90 100 110
2.0
2.2
2.4
2.6
2.8
3.0
3.2
Sh
ear
Sti
ffn
ess
(g.c
m/d
eg)
Formulation Conc. (g/l)
Red
Yellow
Blue
Green
Black
Figure 4.2 Effect of varying the concentration of the formulation applied to cotton
fabric on the KES-F shear stiffness, G
Chapter 4 Investigation of Basic Binder System
94
0 10 20 30 40 50 60 70 80 90 100 110
7
8
9
10
11
Sh
ear
Hy
ster
esis
(g
/cm
)
Formulation Conc. (g/l)
Red
Yellow
Blue
Green
Black
Figure 4.3 Effect of varying the concentration of the formulation applied to cotton
fabric on the KES-F shear hysteresis at 5o, 2HG5
4.3.2 Modified Matrix OSD System
4.3.2.1 Treatment on Cotton
In subsequent studies a higher concentration of the stock formulation, 150g/L, was
used to achieve a better understanding of the matrix OSD system. A wetting agent
was also added in order to achieve treatment uniformity. Although the concentration
of formulation was increased to a relatively high concentration of 150g/L, it is
shown in Table 4.5 that dry rub fastness and wash fastness were maintained at an
acceptable performance level of 4/5 to 5. The wet rub fastness was relatively poor at
the higher concentration and becomes worse with the increase of depth. The reason
why colour strength was different for the same colour at the same concentration to
the previous dyeing applications was probably due to different pigments were used.
Chapter 4 Investigation of Basic Binder System
95
From Figures 4.1-4.3, the main trend of each handle property for different colours
was almost the same, so in this section only blue dyed samples are shown as Figures
4.4-4.6. The numerical values are slightly different from those observed in Figure
4.1-4.3, due to the change of cotton fabric quality. However, the main trends were
still observed.
Figure 4.7(a)-(c) show the SEM micrograph images of untreated cotton fabric that
had been dry and wet rubbed, and it is evident that the wet-rubbed damage is more
obvious than in the dry-rubbed materials due to the water swelling the fibre and
increasing its propensity to wet fibrillation and reducing interface adhesion.
Figures 4.8-4.10 illustrate the SEM micrographs of fabrics treated with the modified
Matrix OSD system without pigment. The binder concentrations are 9g/L, 90g/L and
135g/L, which was the same as the binder concentration in the formulation.
Compared with the micrographs of the untreated cotton, it was apparent that there
was polymer binder deposited on the surface of fibres and at the 9g/L binder
concentration application threadlike interfibre bonding was observed. While at
90g/L and 135g/L application levels the spaces between fibres are filled by binder,
suggesting that the film on the fabrics becomes thicker and covers the fabrics more
uniformly and interfibre interstices.
The micrographs of the dyed modified matrix OSD dyeing system indicated that
although this binder film is beneficial for cotton surface protection, the colour loss
increased, especially under the wet rub conditions and at the higher concentrations.
The SEM micrographs of the wet-rubbed areas, Figures 4.11-4.19, show that when
the formulation concentration increased, the condition of the fabric surface was
increasingly disrupted but that the effect of the pigment type was not significant.
Red and yellow pigment dyed samples were tested with the Martindale abrasion
Chapter 4 Investigation of Basic Binder System
96
tester, as shown in Table 4.7. The number of rubs, when two yarns were broken, is
almost the same for red and yellow pigment dyed samples. Higher formulation
concentrations increased the number of rubs to break, indicating the fabrics were
being “protected” by the polymer overlayer. When the formulation concentration
was 10g/L, the number of rub cycles was slightly lower than the untreated cotton,
maybe because the binder layer was not thick enough to avoid cotton damage during
high temperature fixation and as it peels away it removes the cotton subsurface as
well. The SEM of abraded fabrics was also observed, Figure 4.20, and again
reflected the same behaviour flat abrasion performance.
Table 4.5 Effect of varying the concentration of the formulation applied to cotton
fabric on the rub and wash fastness
Formulation
Conc. g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow
10 5 4 5 5
100 5 2/3 5 5
150 4/5 2/3 4/5 5
Red
10 4/5 3/4 5 5
100 4/5 2/3 4/5 5
150 4/5 2 4/5 5
Blue
10 4/5 3 5 5
100 4/5 2/3 4/5 5
150 4/5 2 4/5 4/5
Table 4.6 Effect of varying the concentration of the formulation applied to cotton
fabric on the colour strength
Formulation Conc. g/L λmax (nm) K/S
Yellow
10 430 1.08
100 440 5.98
150 440 7.76
Red
10 570 0.68
100 570 5.17
150 570 6.25
Blue
10 620 0.78
100 610 6.49
150 610 8.18
Chapter 4 Investigation of Basic Binder System
97
Table 4.7 Effect of varying the concentration of the formulation applied to cotton
fabric on the Martindale flat abrasion
Formulation Conc. g/L Rubs
(1 Yarn broken)
Rubs
(2 yarns broken)
Yellow
10 12000 12125
100 14025 15375
150 23000 25000
Red
10 10000 10750
100 16500 17750
150 25500 26000
Untreated cotton 0 12500 14000
0 20 40 60 80 100 120 140 160
0.10
0.15
0.20
Ben
din
g S
tiff
nes
s (g
.cm
2/c
m)
Formulation Conc. (g/l)
Figure 4.4 Effect of varying the concentration of the formulation applied to cotton
fabric on the KES-F bending stiffness, B
Chapter 4 Investigation of Basic Binder System
98
0 20 40 60 80 100 120 140 160
1.5
2.0
2.5
3.0
3.5
4.0
Sh
ear
Sti
ffn
ess
(g/c
m·d
eg)
Formulation Conc. (g/l)
Figure 4.5 Effect of varying the concentration of the formulation applied to cotton
fabric on the KES-F shear stiffness, G
0 20 40 60 80 100 120 140 160
5
6
7
8
9
Sh
ear
Hy
ster
esis
(g
/cm
)
Formulation Conc. (g/l)
Figure 4.6 Effect of varying the concentration of the formulation applied to cotton
fabric on shear hysteresis at 5o, 2HG5
Chapter 4 Investigation of Basic Binder System
99
(a) Plain cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.7 SEM micrographs of untreated cotton
(a) Binder covered cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.8 SEM micrographs of 9 g/L binder covered cotton
Chapter 4 Investigation of Basic Binder System
100
(a) Binder covered cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.9 SEM micrographs of 90g/L binder covered cotton
(a) Binder covered cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.10 SEM micrographs of 135 g/L binder covered cotton
Chapter 4 Investigation of Basic Binder System
101
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.11 SEM micrographs of yellow dyed cotton at a stock formulation
concentration of 10g/L
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.12 SEM micrographs of yellow dyed cotton at a stock formulation
concentration of 100 g/L
Chapter 4 Investigation of Basic Binder System
102
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.13 SEM micrographs of yellow dyed cotton at a stock formulation
concentration of 150g/L
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.14 SEM micrographs of red dyed cotton at a stock formulation
concentration of 10g/L
Chapter 4 Investigation of Basic Binder System
103
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.15 SEM micrographs of red dyed cotton at a stock formulation
concentration of 100g/L
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.16 SEM micrographs of red dyed cotton at a stock formulation
concentration of 150g/L
Chapter 4 Investigation of Basic Binder System
104
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.17 SEM images of blue dyed cotton at stock formulation conc.10g/L
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.18 SEM micrographs of blue dyed cotton at a stock formulation
concentration of 100g/L
Chapter 4 Investigation of Basic Binder System
105
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 4.19 SEM micrographs of blue dyed cotton at a stock formulation
concentration 150g/L
(a) 10g/L
(b) 100g/L (c) 150g/L
Figure 4.20 SEM micrographs of abraded red dyed cotton
Chapter 4 Investigation of Basic Binder System
106
4.3.2.2 Treatment on PET and Polycotton
Examination of Tables 4.8 and 4.9 indicates the fastness results of cotton, PET and
poly/cotton red pigment Matrix OSD (with softener) dyed fabrics where the dyed
cotton and PET fabrics offer similar performances. Interestingly the poly/cotton
fabric showed better wet fastness than the comparable cotton and polyester fabrics
but the colour strength of pigment dyed cotton fabrics was significantly higher than
the poly/cotton and polyester fabrics, Table 4.9. This effect may be due to the greater
amount of the colourant/binder formulation bonding to the cotton fabric or more
likely an optical effect related to fabric or fibre structure.
Table 4.8 Effect of varying the concentration of the pigment formulation applied to
cotton, PET and polycotton fabrics on the fastness
Formulation Conc.
g/L
Rub fastness Wash fastness
Dry Wet Colour Change Staining
Cotton
Red 10 4/5 3/4 5 5
Red 100 4/5 2/3 4/5 5
Red 150 4/5 2 4/5 5
PET
Red 10 4 3/4 4/5 5
Red 100 4 2/3 4/5 5
Red 150 4/5 2 4 4/5
Polycotton
Red 10 4/5 4/5 5 5
Red 100 4/5 3 5 5
Red 150 4/5 3/4 5 5
Table 4.9 Effect of varying the concentration of the pigment formulation applied to
cotton, PET and polycotton fabrics on the colour strength
Formulation Conc. g/L λmax K/S
Cotton
Red 10 570 0.68
Red 100 570 5.17
Red 150 570 6.25
PET
Red 10 570 0.46
Red 100 570 2.44
Red 150 570 3.64
Polycotton
Red 10 570 0.44
Red 100 570 3.51
Red 150 570 5.14
Chapter 4 Investigation of Basic Binder System
107
4.3.3 Effect of Curing Time on the Performance of the Matrix OSD
System
Although one minute was the recommended curing period for the Matrix OSD
system, a longer period of time was evaluated to establish the optimal cure
conditions. However, it was apparent an increase of the curing time offered no
benefits for dry rub fastness and wash fastness, Tables 4.10-4.12. In contrast for the
wet rub fastness performances there were some marginal benefits for the pale shades,
in terms of extending the curing time to 2-3 minutes. However it is likely when the
additional energy increase is considered, one minute may well be the “best” curing
time in accordance with the Matrix OSD recommendations.
Table 4.10 Effect of different curing times on the fastness of yellow pigment dyed
cotton fabric
Formulation
Conc. g/L
Curing time
min
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow 10
1 5 4 5 5
1.5 5 4 5 5
2 5 4/5 5 5
3 5 4/5 5 5
4 5 4 5 5
5 4/5 4 5 5
7 5 4 5 5
Yellow 100
1 5 2/3 5 5
1.5 4/5 3 4/5 5
2 5 3 5 5
3 5 3 5 5
4 4/5 3/4 4/5 5
5 4/5 3/4 4/5 5
7 5 3/4 4/5 5
Yellow 150
1 4/5 2/3 4/5 5
1.5 4/5 2/3 4 5
2 5 3 5 5
3 5 3 5 5
4 4/5 2/3 4/5 5
5 4/5 3 4/5 5
7 5 4 4/5 5
Chapter 4 Investigation of Basic Binder System
108
Table 4.11 Effect of different curing times on the fastness of red pigment dyed cotton
fabric
Formulation
Conc. g/L
Curing time
min
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Red 10
1 4/5 3/4 5 5
1.5 4/5 3/4 4/5 5
2 4/5 3/4 4/5 5
3 4/5 3/4 4/5 5
4 4/5 4 4/5 5
5 4/5 4 4/5 4/5
7 4/5 4 4/5 4/5
Red 100
1 4/5 2/3 4/5 5
1.5 4/5 2 4/5 4/5
2 4/5 2/3 4/5 5
3 4/5 2 4/5 5
4 4/5 3 4/5 5
5 4/5 2/3 4/5 5
7 4/5 2/3 4/5 5
Red 150
1 4/5 2 4/5 5
1.5 4/5 2/3 4 4/5
2 4/5 2 4/5 5
3 4/5 2/3 4/5 5
4 4/5 2/3 4/5 5
5 5 2/3 4/5 5
7 4/5 2/3 4/5 5
Chapter 4 Investigation of Basic Binder System
109
Table 4.12 Effect of different curing times on the fastness of blue pigment dyed cotton
fabric
4.3.4 Performance of Matrix OSD without Softener System
In this system, the effect of varying pigment formulation concentration was the same
as in the standard matrix OSD system where colour strength increased with pigment
concentration, Table 4.14. However the absence of the silicone softener appears to
have resulted in a decrease in colour strength which may be due to the interaction of
the light with the “reflective” surface silicone layer. Similarly when KES-F fabric
handle parameters were compared, the binder with softener appears to be less stiff,
Figures 4.21-4.23, due the lubricating effect of the silicone softener. However the
Formulation
Conc. g/L
Curing time
min
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Blue 10
1 4/5 3 5 5
1.5 4/5 3/4 4 5
2 4/5 4 4/5 5
3 4/5 4 4/5 5
4 4/5 4 4 5
5 4/5 4 4/5 5
7 4/5 4/5 4/5 5
Blue 100
1 4/5 2/3 4/5 5
1.5 4 2/3 4 4/5
2 4/5 2 4/5 4/5
3 4/5 2/3 4/5 4/5
4 4/5 2/3 4/5 4/5
5 4/5 3 4/5 4/5
7 4/5 3 4/5 5
Blue 150
1 4/5 2 4/5 5
1.5 4/5 2 4 4/5
2 4/5 2/3 4 4/5
3 4/5 2/3 4 4/5
4 5 2 4/5 5
5 4/5 3 4/5 5
7 4/5 3 4/5 5
Chapter 4 Investigation of Basic Binder System
110
reduction in stiffness becomes less obvious as the binder concentration was
increased and interfibre bonding increased.
Examination of the rub and wash fastness data, Table 4.13, indicated that in general
the presence of the softener had a beneficial effect on dry and wet abrasion and wash
fastness. These beneficial effects can be related to the lubricating effect of the
silicone in reducing dry and wet abrasion effects.
Table 4.13 Effect of varying concentration of formulation applied to cotton fabric on
rub and wash fastness
Formulation
Conc. g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow
10 4/5 4 5 5
100 4/5 3 5 5
150 4/5 3 5 5
Red
10 4/5 3 4/5 5
100 4/5 3 4 4/5
150 4/5 2/3 4 4/5
Blue
10 4/5 3 4 5
100 4 2 3/4 5
150 4 2 3/4 4/5
Table 4.14 Effect of varying concentration of formulation applied to cotton fabric on
colour strength
Formulation Conc. g/L λmax K/S
Yellow
10 430 0.90
100 440 4.50
150 440 5.59
Red
10 570 0.62
100 570 4.46
150 570 5.29
Blue
10 620 0.63
100 620 3.85
150 610 6.32
Chapter 4 Investigation of Basic Binder System
111
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160
0.1
0.2
0.3
0.4
Ben
din
g S
tiff
nes
s (g
.cm
2/c
m)
Formulation Conc. (g/l)
without softener
with softener
Figure 4.21 Effect of softener incorporated into binder system on the bending
stiffness, B, of pigment dyed cotton fabric
0 20 40 60 80 100 120 140 160
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Shea
r S
tiff
nes
s (g
/cm
¡¤deg
)
Formulation Conc. (g/l)
without softener
with softener
Figure 4.22 Effect of softener incorporated into binder system on the shear stiffness,
G, of pigment dyed cotton fabric
Chapter 4 Investigation of Basic Binder System
112
0 20 40 60 80 100 120 140 160
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
Shea
r H
yst
eres
is (
g/c
m)
Formulation Conc. (g/l)
without softener
with softener
Figure 4.23 Effect of softener incorporated into binder system on the shear hysteresis
at 5o, 2HG5, of pigment dyed cotton fabric
4.4 Conclusions
Matrix OSD pigment dyeing was reported to offer benefits in terms of processing
cost and environmental impact. From initial studies it is apparent that while dry rub
fastness, mechanical rigidity and washing performance are generally acceptable wet
rub fastness presents a technical challenge. On increasing the pigment incorporated
into the surface binder film colour strength increased but fastness properties
decreased and reflect the integrity of the film being compromised by the higher
pigment concentrations.
The pigment dyeability of the cellulosic fabric was better than the 100% polyester
synthetic fabric and poly/cotton blend. However, the blend fabric offers better
fastness than the individual 100% fabrics and further work in this area should be
Chapter 4 Investigation of Basic Binder System
113
undertaken.
SEM analyses demonstrated the presence of the polymer binder on the fibre surface
and between the fibres at higher application levels. The “protective effect” of the
binder on the cotton fibre/fabric in increasing the number of cycles to failure in the
Martindale Flat Abrasion test was due to this polymer binder overlayer. However,
with the increase of formulation concentration, more pigment was present on the
fabric surface and accordingly caused more colour loss during dry and wet rubbing.
However the presence of these colourants did not affect the fabric integrity/strength
but rather were a visual effect.
The recommended curing time for the Matrix OSD system was one minute and was
recommended as the optimal balance of end-fabric performance and processing
costs. However results in this study indicated marginally enhanced fastness can be
achieved by increasing the cure temperature to 2-3 minutes.
The presence of silicone softener in the binder formulation was found to offer
benefits in terms of colour strength, handle and fastness. These effects were most
likely due to the surface film increasing specular reflectance and lubrication at the
materials interface.
4.5 References
1. Binders for Textile Applications. Cotton Incorporated Technical Bulletin,
2004, ISP(1008): p.1-16.
2. Giesen, V. and Eisenlohr, R., Pigment Printing. Review of Progress in
Coloration and Related Topics, 1994, 24(1): p.26-30.
3. Humphries, A., Muff, J. R., and Seddon, R., Aqueous System for Pigment
Printing, Colourage, 1985, 32(5): p.15-27.
Chapter 4 Investigation of Basic Binder System
114
4. Bridge, C., Pigment Developments for the Printing Inks for the 90s. Journal
of the Oil & Colour Chemists Association, 1990, 73(7): p.282-284.
5. Khanna, S. R., Pigment Color Printing in Aqueous Phase, Colourage, 1992,
39(3): p.13-16.
6. Friedman, E. A., An Introduction to Phosphate Binders, Kidney International.
Supplement, 2005(96): p.2-6.
7. Wu, Q., Process and Auxiliary of Pigment Pad Dyeing. Dyeing and Finishing,
2007(12): p.3.
8. Yao, D., Surface Modification of Ultra-fine Pigment and Its Dyeing
Performance, Dyeing and Finishing, 2011(4): p.5.
9. Meng, C., An, G., and Cao, Y., Discussion on Pigment Dyeing of Modified
Cotton Fabric, Textile Auxiliaries, 2011, 28(1): p.4.
10. Yang, Y. and Xu, L., Optimization Process for Pad Dyeing of Cotton. Dyeing
and Finishing, 2009(18): p.4.
11. Wei, Q., Surface Modification of Textiles, 2009, Cambridge: Woodhead Pub.
xx, p.337.
12. Vigo, T. L., Textile Processing and Properties : Preparation, Dyeing,
Finishing and Performance, 1994, Amsterdam ; London: Elsevier. xvii,
p.479.
13. Hammonds, A. G., Introduction to Binders. Pigment Printing Handbook,
1995, p.57.
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
115
Chapter 5 Investigation into the Effect of
Crosslinkers, Cationisation and Surface
Modification on the Performance of Matrix
OSD Treatments
5.1 Introduction
The purpose of the cationic pre-treatment of cotton was to determine whether
improved dyeability with the pigment binder system could be achieved by
introducing positively charged sites onto the cotton surface. Previous studies have
investigated the effect of cationizing cotton on the colouration of cotton with direct
dyes, acid dyes, reactive dyes, and pigment with improvements in colour yield and
colour fastness reported [1, 2]. For pigment dyeing, modification of the pigment
dyeing system to achieve better results has been studied through the use of
fastness-improving reagents and of nanoscale pigment dispersion [3, 4]. In this
investigation, cotton has been modified using a cationic reagent Cibafix ECO which
is proprietary polyethylene polyamine manufactured and supplied by Ciba Specialty
Chemicals. It is also free from formaldehyde and zinc, and used in the dyeing
industry as a wet fastness modifier to improve dyeing [5]. Wang and Zhang have
recently evaluated Cibafix ECO as a means to improve pigment printing (not
pigment dyeing), and reported that the rub fastness improved and was only
acceptable when the fastness-improving reagent was applied [3].
The binder film which links fabrics and pigment is formed during the dry heat fixing
process which usually consists of dry heat and a change in pH value, bringing about
either self-crosslinking or reaction with other suitable crosslinking agents [2]. In this
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
116
chapter, four crosslinkers (Nanolink, citric acid, Dimethylol Dihydroxy Ethylene
Urea (DMDHEU) and Knittex MLF NEW) were used in the binder system.
Although Matrix OSD is a self-crosslinking binder, these preliminary studies were
undertaken to explore the effect of external crosslinkers in this binder system and if
possible further benefits could be identified.
In this chapter, fabrics were also pretreated by ultraviolet/ozone (UVO) with the
view to specifically modifying the surface interface as distinct from the bulk
modifications which would also affect the surface. UVO treatments were originally
considered as a surface cleaning method which was used to modify the surface
chemistry and improve the wetting characteristics of natural and synthetic polymers
[6, 7]. It functions through the combined effects of UV light and ozone produced in
situ from a gas phase photo-dissociation of molecular oxygen. Previous studies have
indicated the efficacy of UVO treatments in removing surface hydrophobes from
wool and other material surfaces, imparting wettability and improving dyeability
and shrink resistance [8, 9].
Much research has been conducted on the dyeing of cotton has focused on changing
the bulk and surface chemistry, through related processing such as dyeing, bleaching,
and washing. However, in most of the relative dyeing studies, the colourants used
were dyes, not pigments.
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
117
5.2 Experimental Work
5.2.1 Materials
Fabrics 100% bleached plain woven cotton fabric, 191.5g/m2, was also
supplied by Whaleys, UK.
Pigments Lyosperse red 2BN LIQ was supplied by Huntsman, UK.
Lyosperse yellow MR LIQ was supplied by Huntsman, UK.
Minerprint blue B, was supplied by Quality Colours, UK.
Binders Matrix OSD was supplied by Beyond Surface Technologies,
Switzerland.
Wetting agent Alcopol 070 was supplied by Huntsman, UK.
Crossliners Nanolink was supplied by Devan-PPT Chemicals, UK.
Citric acid was purchased from Aldrich Chemicals, UK.
DMDHEU was kindly supplied by Huntsman, UK.
Knittex MLF NEW was supplied by Huntsman, UK.
5.2.2 Pigment Dyeing System
The standard Matrix OSD dyeing system, discussed in 4.2.4 was used as the pigment
dyeing system in this project component.
5.2.3 Fabric Pretreatment by Cationic Fixing Agent
Before applying the pigment dyeing solution onto the cotton fabric, the cationic
fixing agent Cibafix ECO was applied as a pre-treatment to the fabrics at
concentrations of 0.5%, 1% and 2% on the weight of fabric (owf) by an exhaustion
method at 40℃ for 30 minutes with a liquor to fabric ratio of 20:1. After rinsing in
water and air-drying, the treated fabrics were then pigment-dyed under standard
conditions.
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
118
5.2.4 Crosslinker Treatment
Nanolink
Cotton fabrics were pre-treated with 2.0% o.w.f. Nanolink by exhaustion from a
treatment bath at pH5, adjusted with acetic acid, and the exhaustion bath
temperature was heated from 20℃ to 40℃ for 10 minutes. After rinsing in water
the fabrics were air-dried, and then pigment-dyed under standard conditions (in
4.2.4).
Citric Acid
Two different kinds of citric acid applications were evaluated, as a pre-treatment and
incorporation of the citric acid into the treatment formulation.
a. The cotton fabrics were padded at 80% w.p.u., with the concentrations of 1g/L,
3g/L, 5g/L, 10g/L, 20g/L, 40g/L, 60g/L, 100g/L and 140g/L citric acid solutions
with the same amount of sodium hypophosphite incorporated. The fabrics were
dried at 100℃ for 3 minutes and then heat cured at 180℃ for 90 seconds. The
fabrics were rinsed in water and were then air-dried, followed by standard
pigment-dyeing (in 4.2.4).
b. Citric acid was incorporated with the pigment dyeing solution at the same
concentration as stated in previous method and pigment dyed under standard
conditions (in 4.2.4).
Knittex MLF New
Two different kinds of Knittex MLF New applications were performed, either as a
pre-treatment and incorporated into the pigment dyeing formulation.
a. The cotton fabrics were pre-treated with either 40g/L or 60g/L Knittex MLF
New by padding 80% w.p.u., drying at 100℃ for 3 minutes and then heat
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
119
curing at 180℃ for 90 seconds. The fabric samples were then pigment dyed
under standard conditions.
b. Knittex MLF New, 40-60 g/L, was combined with the pigment dyeing solution
and then pigment dyed as reported earlier.
Citric Acid with Knittex MLF New
The cotton fabrics were pre-treated with a citric acid and Knittex MLF New
combination, which was padded at 80% w.p.u. at the concentration of 40g/L and
60g/L, dried at 100℃ for 3 minutes, heat cured at 180℃ for 90 seconds and then
pigment dyed.
DMDHEU
The cotton fabrics were pre-treated with 100g/L DMDHEU and 10g/L magnesium
chloride, padded at 80% w.p.u., dried at 100℃ for 3 minutes, heat cured at 180℃
for 90 seconds. Following water rinsing and air drying the fabric samples were
pigment-dyed.
5.2.5 UVO treatment
Before fabric samples were dyed with the standard Matrix OSD system, the cotton
fabrics were pre-treated by UVO for 5, 10 and 15 minutes on each face of the fabric.
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
120
5.3 Results and Discussion
5.3.1 Effect of Cationization Treatment
Cationization of the cotton fabrics improved the wet rub fastness for the yellow
pigment dyed fabrics but offered almost no effect on the dry rub fastness, Table 5.1.
However surprisingly for the red and blue pigment dyed fabrics the cationic fixing
agent had relatively little effect on the fastness properties. Interestingly, cationization
treatment caused more change of colour after washing when 0.5% and 1% cationic
fixing agent were applied. When 2% cationic fixing agent was applied, the change of
colour after washing was better than with 0.5% and 1% cationic fixing agent, however,
the results are still lower than the control reference samples. It may be because the
temperature, at which Cibafix ECO can improve wash fastness, is identified as 50℃
in the Ciba technical data sheet, but the washing temperature used in this study was
60℃.
The colour strength K/S of the pigment dyed fabrics appeared to increase with
increasing application levels of the cationic reagent to the cotton, Figure 5.1. This
may be related to increased exhaustion of the pigment dyeing formulation onto the
positively charged fabric.
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
121
Table 5.1 Effect of varying the cationic fixing agent concentration on the fastness of
pigment dyed cotton fabric
Formulation
Conc. g/L
Cationic fixing
agent %
Rub Fastness Wash Fastness
Dry Wet Colour change Staining
Yellow 10
0 5 4 5 5
0.5 4/5 4 4/5 5
1 4/5 4 4/5 4/5
2 4/5 4/5 5 5
Yellow 100
0 5 2/3 5 5
0.5 4/5 3/4 4/5 4/5
1 4/5 4 5 4/5
2 4/5 4 5 4/5
Yellow 150
0 4/5 2/3 4/5 5
0.5 4/5 3/4 4/5 4/5
1 4/5 3 5 4/5
2 4/5 3/4 4/5 4/5
Red 10
0 4/5 3/4 5 5
0.5 4 3 4/5 5
1 4 3 4/5 4/5
2 4/5 4 4/5 5
Red 100
0 4/5 2/3 4/5 5
0.5 4 2 3/4 4
1 4/5 2 3/4 4/5
2 4/5 2/3 4 4/5
Red 150
0 4/5 2 4/5 5
0.5 4 2 3/4 4
1 4 2/3 4 4/5
2 4/5 2/3 4 4/5
Blue 10
0 4/5 3 5 5
0.5 4 3 4 5
1 4 3 4/5 4/5
2 3/4 3 4/5 5
Blue 100
0 4/5 2/3 4/5 5
0.5 4 2 3/4 4/5
1 4 2/3 3/4 4/5
2 4 2/3 4 4/5
Blue 150
0 4/5 2 4/5 4/5
0.5 4 2 3/4 4/5
1 4 2/3 4 4/5
2 4 2/3 4/5 4/5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
122
Figure 5.1 Effect of varying the cationic fixing agent concentration on the colour
strength of pigment dyed cotton fabric
5.3.2 Effect of Crosslinkers
5.3.2.1 Effect of Nanolink
Nanolink is reported by Devan-PPT to function effectively as a covalent linking
agent and increase surface adhesion between coatings and the fibre substrate.
However it is apparent that Nanolink imparts no beneficial effects on dry rub
fastness and may even slightly decrease performance for darker colours, Table 5.2.
However, the Nanolink pre-treatment clearly improved the wet rub fastness for all
colours and shades, especially for the yellow pigment shades. Wash fastness is rated
as excellent similar to the standard control samples.
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
123
Table 5.2 Effect of 2% o.w.f. application of Nanolink on the fastness properties of of
pigment dyed cotton fabric
a- treated
b- reference control
5.3.2.2 Effect of Citric Acid
When citric acid was incorporated into the pigment dyeing system, insoluble
precipitates substrates appeared in the solution. Heating the solution and changing
the addition order into the aqueous formulation were assessed, but the deposits still
formed. Therefore, only pre-treatment of the fabric with citric acid was examined.
As can be seen from the data in Table 5.3-5.5, when the fabrics were pre-treated
with citric acid, the wet rub fastness was improved, especially for the light colours.
In contrast the dry rub fastness and wash fastness remained relatively unchanged but
still at commercially acceptable performance levels. The wet rub fastness
performance levels at the 5g/L concentration and most likely functions by reducing
the swelling of crosslinked cotton interface and maintaining coating adhesion. The
samples were also pre-treated with citric acid at 40g/L, 60g/L, 100g/L and 140g/L,
but the results showed no additional benefit. The results at 40g/L and 60g/L will be
presented in Table 5.3-5.5 to compare with Knittex MLF New treatments.
Formulation
Conc. g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
a b a b a b a b
Yellow
10 5 5 4/5 4 5 5 5 5
100 4/5 5 4 2/3 5 5 5 5
150 4/5 4/5 4 2/3 5 4/5 5 5
Red
10 4/5 4/5 3/4 3/4 5 5 5 5
100 4/5 4/5 3 2/3 4/5 4/5 5 5
150 4/5 4/5 2/3 2 5 4/5 5 5
Blue
10 4/5 4/5 3/4 3 4/5 5 5 5
100 4 4/5 3/4 2/3 5 4/5 5 5
150 4 4/5 3 2 5 4/5 5 5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
124
Table 5.3 Effect of citric acid pre-treatment of cotton on the fastness of the yellow
pigment dyed fabric
Formulation
Conc. g/L
Citric acid
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow 10
0 5 4 5 5
1 5 4 5 5
3 5 4/5 5 5
5 4/5 4/5 4/5 5
10 4/5 4/5 4/5 5
20 4/5 4/5 4/5 5
Yellow 100
0 5 2/3 5 5
1 5 2/3 4/5 5
3 5 3/4 4/5 5
5 5 4 4/5 5
10 4/5 3/4 4/5 5
20 4/5 4 4/5 5
Yellow 150
0 4/5 2/3 4/5 5
1 4/5 2 4/5 5
3 5 3 4/5 5
5 4/5 4 4/5 5
10 4/5 3/4 4/5 5
20 4/5 3 4/5 5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
125
Table 5.4 Effect of citric acid pre-treatment of cotton on the fastness of the red
pigment dyed fabric
Formulation
Conc. g/L
Citric acid
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Red 10
0 4/5 3/4 5 5
1 4/5 3/4 4/5 5
3 4/5 4 4/5 5
5 4/5 4 4/5 5
10 4/5 4 4/5 5
20 4/5 4 4/5 5
Red 100
0 4/5 2/3 4/5 5
1 4/5 3 4/5 4/5
3 4/5 3/4 4/5 4/5
5 4/5 3/4 4/5 4/5
10 4/5 2/3 4/5 5
20 4/5 3 4/5 5
Red 150
0 4/5 2/3 4/5 5
1 4/5 2/3 4 4/5
3 4/5 3 4/5 4/5
5 4/5 3 4/5 4/5
10 4/5 2/3 4/5 4/5
20 4/5 2/3 4/5 5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
126
Table 5.5 Effect of citric acid pre-treatment of cotton on the fastness of the blue
pigment dyed fabric
5.3.2.3 Effect of Knittex MLF New
The effect of pre-treatment of the pigment dyed cotton fabric with Knittex MLF
New, Table 5.6, was to significantly improve the wet rub fastness at both low and
high pigment levels while the dry rub fastness and wash fastness remain
commercially acceptable. Increasing the application concentration from 40g/L to
60g/L had little benefits, so 40g/L was selected for further work.
After identifying the benefit of Knittex MLF New pre-treatment, the effect of a
combined pigment dyeing treatment incorporating Knittex MLF New was also
Formulation
Conc. g/L
Citric acid
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Blue 10
0 4/5 3 5 5
1 4/5 4 4/5 5
3 4/5 4 4/5 5
5 4/5 4 4/5 4/5
10 4/5 4 4/5 4/5
20 4/5 3/4 4/5 4/5
Blue 100
0 4/5 2/3 4/5 5
1 4/5 3 4/5 4/5
3 4/5 3 4/5 4/5
5 4/5 3 4/5 4/5
10 4/5 3 4/5 4/5
20 4/5 3 4/5 4/5
Blue 150
0 4/5 2 4/5 5
1 4/5 2/3 4 4/5
3 4/5 3 4 4/5
5 4/5 2/3 4 4/5
10 4/5 2/3 4 4/5
20 4 2/3 4 4/5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
127
assessed. However the improvement in the wet rub fastness performance results was
not as good as the pre-treated fabrics, Table 5.7. Samples probably due to the
increased wet swelling and lower cohesion between the coating and the fibre
interface. Nevertheless it was still beneficial for wet rub fastness particularly for the
light pale shade, especially at the concentration of 40g/L.
Table 5.6 Effect of the application of Knittex MLF New pre-treatment to cotton on
the fastness of pigment dyed fabric
Formulation
Conc. g/L
Knittex
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow 10
0 5 4 5 5
40 5 4/5 4/5 5
60 5 4/5 4/5 5
Yellow 100
0 5 2/3 5 5
40 4/5 4 4/5 5
60 4/5 3/4 4/5 5
Yellow 150
0 4/5 2/3 4/5 5
40 4/5 4 4/5 5
60 4/5 4 4/5 5
Red 10
0 4/5 3/4 5 5
40 4/5 4 4/5 5
60 4/5 4 4/5 5
Red 100
0 4/5 2/3 4/5 5
40 4/5 3/4 4/5 5
60 4/5 3 4/5 5
Red 150
0 4/5 2 4/5 5
40 4/5 3/4 4/5 5
60 4/5 4 4/5 5
Blue 10
0 4/5 3 5 5
40 4/5 4 4/5 5
60 4/5 3/4 4/5 4/5
Blue 100
0 4/5 2/3 4/5 5
40 4/5 3/4 4/5 5
60 4/5 4 4/5 5
Blue 150
0 4/5 2 4/5 5
40 4/5 4 4/5 5
60 4/5 3/4 4/5 5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
128
Table 5.7 Effect of incorporating Knittex MLF New into the pigment dyeing
formulation applied to cotton fabric on colour fastness
5.3.2.4 Effect of Citric Acid and Knittex MLF New
The effect on pigment dyeing fastness by pre-treating the cotton fabric with a
combination of citric acid and Knittex MLF New and treating with a combination
mixture of Knittex MLF New and citric acid at 40g/L and 60g/L, shown in Tables
Formulation
Conc. g/L
Knittex
g/L
Rub Fastness Wash Fastness
Dry Wet Colour change Staining
Yellow 10
0 5 4 5 5
40 5 5 5 5
60 5 4/5 4/5 5
Yellow 100
0 5 2/3 5 5
40 5 4 4/5 5
60 5 3 4/5 5
Yellow 150
0 4/5 2/3 4/5 5
40 4/5 3 4/5 5
60 5 3/4 4/5 5
Red 10
0 4/5 3/4 5 5
40 5 4/5 4/5 5
60 5 4/5 4/5 5
Red 100
0 4/5 2/3 4/5 5
40 4/5 2 4/5 5
60 4/5 2/3 4/5 5
Red 150
0 4/5 2 4/5 5
40 4/5 3 4/5 5
60 4/5 3 4/5 5
Blue 10
0 4/5 3 5 5
40 4/5 4 4/5 5
60 4/5 4 4/5 5
Blue 100
0 4/5 2/3 4/5 5
40 4 3 4/5 5
60 4 2 4/5 5
Blue 150
0 4/5 2 4/5 5
40 4 3/4 4/5 5
60 4/5 2/3 4/5 5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
129
5.8-5.10. The obvious drawback of pre-treating with the mixture of citric acid and
Knittex MLF New was observed in the wet rub fastness and dry rub fastness
performances, where lower fastness than the control fabrics in almost all colours and
shades was demonstrated. The addition of citric acid offers almost no benefit for
fastness, while Knittex MLF New imparts significant improvement on wet rub
fastness. As mentioned in Section 5.3.2.3, 40g/L Knittex MLF New shows the better
application concentration.
Table 5.8 Effect of pre-treatment with citric acid and Knittex MLF New on the
fastness performance of yellow pigment dyed cotton fabric
Formulation
Conc. g/L
Citric acid
g/L
Knittex
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow 10
0 0 5 4 5 5
40 0 5 4/5 5 5
60 0 5 4/5 5 5
0 40 5 4/5 4/5 5
0
40
60
60
40
60
5
4/5
4/5
4/5
4
3/4
4/5
5
4/5
5
5
5
Yellow 100
0 0 5 2/3 5 5
40 0 4/5 2/3 4/5 5
60 0 4/5 2/3 4/5 5
0 40 4/5 4 4/5 5
0
40
60
60
40
60
4/5
4/5
4
3/4
2/3
1/2
4/5
4/5
4/5
5
5
5
Yellow 150
0 0 4/5 2/3 4/5 5
40 0 4/5 2 4/5 5
60 0 4/5 2 4/5 5
0 40 4/5 4 4/5 5
0
40
60
60
40
60
4/5
4
4/5
4
1/2
1/2
4/5
4/5
4/5
5
5
5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
130
Table 5.9 Effect of pre-treatment with citric acid and Knittex MLF New on the
fastness performance of red pigment dyed cotton fabric
Formulation
Conc. g/L
Citric acid
g/L
Knittex
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Red 10
0 0 4/5 3/4 5 5
40 0 4/5 4 5 5
60 0 4/5 4 5 5
0 40 4/5 4 4/5 5
0
40
60
60
40
60
4/5
4/5
4
4
4
3
4/5
5
4/5
5
5
5
Red 100
0 0 4/5 2/3 4/5 5
40 0 4/5 2/3 4/5 5
60 0 4/5 2/3 4/5 5
0 40 4/5 3/4 4/5 5
0
40
60
60
40
60
4/5
4
4
3
2
1/2
4/5
4/5
4/5
5
4/5
4/5
Red 150
0 0 4/5 2 4/5 5
40 0 4/5 2 4/5 5
60 0 4/5 2 4/5 5
0 40 4/5 3/4 4/5 5
0
40
60
60
40
60
4/5
4
4
4
2/3
1/2
4/5
4/5
4/5
5
4/5
4/5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
131
Table 5.10 Effect of pre-treatment with citric acid and Knittex MLF New on the
fastness performance of blue pigment dyed cotton fabric
5.3.2.5 Effect of DMDHEU Pre-Treatment
Table 5.11 presents that the fastness results of cotton fabrics pre-treated with 100g/L
DMDHEU. The data indicates that the DMDHEU modification to the cotton fabric
has a lesser benefit than the Knittex MLF New for the wet rub fastness while dry rub
fastness and wash fastness still remain good. It is likely the difference was due to the
greater crosslinking and embrittlement of the fibre.
Formulation
Conc. g/L
Citric acid
g/L
Knittex
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Blue 10
0 0 4/5 3 5 5
40 0 4/5 3/4 4/5 5
60 0 4/5 3/4 4/5 5
0 40 4/5 4 4/5 5
0
40
60
60
40
60
4/5
4/5
4
3/4
4
4
4/5
5
4/5
4/5
4/5
5
Blue 100
0 0 4/5 2/3 4/5 5
40 0 4 2/3 4/5 5
60 0 4 2/3 4/5 5
0 40 4/5 3/4 4/5 5
0
40
60
60
40
60
4/5
3/4
3
4
2
2
4/5
4/5
4/5
5
4/5
4/5
Blue 150
0 0 4/5 2 4/5 5
40 0 4 2/3 4/5 5
60 0 4 2/3 4/5 5
0 40 4/5 4 4/5 5
0
40
60
60
40
60
4/5
3/4
4
3/4
1/2
2
4/5
4
4
5
4/5
4/5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
132
Table 5.11 Effect of 100g/L DMDHEU pre-treatment on the fastness performance of
pigment dyed cotton fabric
a- Treated by DMDHEU
b- Reference
5.3.3 Effect of UVO Treatment
In previous studies UVO treatment has been used to modify the fabric surface and
improve dyeability and the effectiveness of polymer coating, however in this study
of pigment dyed cotton, the results indicate that UVO treatment imparts relatively
lower fastness performance than the original untreated cotton fabrics. There is a
clear reduction in wet rub fastness and the wash fastness is also adversely affected
by the UVO pre-treatment. The worst colour changing results are observed with the
darkest colours and is probably related to the change in adhesion properties
following surface oxidation. However the cross-staining values are unaffected
indicating the removed colour has little affinity for the test fabrics. Figure 5.2
illustrates that the colour was changed after UVO treatment, probably due to the
yellowness imparted by the treatment.
Formulation Conc.
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
a b a b a b a b
Yellow
10 5 4/5 4/5 3/4 5 5 5 5
100 4/5 4/5 3 2/3 5 4/5 5 5
150 4/5 4/5 2/3 2 4/5 4/5 4/5 5
Red
10 4/5 5 4 4 4/5 5 5 5
100 4/5 5 2/3 2/3 4/5 5 5 5
150 4/5 4/5 2/3 2/3 4/5 4/5 5 5
Blue
10 4/5 4/5 3/4 3 4/5 5 5 5
100 4/5 4/5 3 2/3 4/5 4/5 5 5
150 4 4/5 2/3 2 4/5 4/5 5 5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
133
Table 5.12 Effect of UVO treatment on the fastness performance of pigment dyed
cotton fabric
Formulation Conc.
g/L
Time in UVO
min
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow 10
0 5 4 5 5
5 4/5 3 3/4 5
10 4/5 3 3/4 5
15 4/5 3 3 5
Yellow 100
0 5 2/3 5 5
5 4/5 2/3 3 5
10 4/5 2 3 5
15 4/5 2 2/3 5
Yellow 150
0 4/5 2/3 4/5 5
5 4/5 2/3 3/4 5
10 4/5 2 3/4 5
15 4/5 1/2 3 5
Red 10
0 4/5 3/4 5 5
5 4/5 3 3/4 5
10 4/5 3 3/4 4/5
15 4/5 3 3 5
Red 100
0 4/5 2/3 4/5 5
5 4/5 2 3/4 4
10 4/5 2 3 4/5
15 4/5 2/3 2/3 4/5
Red 150
0 4/5 2 4/5 5
5 4/5 2 4 4/5
10 4 2 2/3 4/5
15 4 2 2/3 4/5
Blue 10
0 4/5 3 5 5
5 4/5 3 2/3 4/5
10 4/5 2/3 2/3 4/5
15 4 2/3 2 4/5
Blue 100
0 4/5 2/3 4/5 5
5 4 1/2 2/3 4/5
10 4 1/2 2 4/5
15 4 1/2 1/2 4/5
Blue 150
0 4/5 2 4/5 4/5
5 4 2 3 5
10 4 2 2 5
15 4 1/2 1/2 4/5
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
134
Figure 5.2 Effect of UVO exposure on the colour strength of pigment dyed cotton
fabric
From the SEM analyses of the abraded standard pigment dyed cotton Section 4.3.2,
the presence of the colourants was not the reason for surface degradation. Therefore
in this study discussion, only the red pigment dyed samples were examined. After
UVO treatment, the degradation showed the same behaviour as the pigment
dyed-only fabric samples, i.e. when the concentration of formulation rises, there was
more binder evident on the fabric. Comparing the dry-rubbed areas with the
wet-rubbed areas, it was apparent that the wet-rubbed areas were damaged more.
The effect of increasing UVO treatment time on rubbing damage is illustrated in
Figures 5.3-5.11. At the concentration levels of 100g/L and 150g/L, the damage
appearance was more obvious with the increase of UVO treatment time.
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
135
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.3 SEM micrographs of 5 minutes-UVO treated red dyed cotton at 10g/L
stock formulation concentration
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.4 SEM micrographs of 10 minutes-UVO treated red dyed cotton at 10g/L
stock formulation concentration
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
136
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.5 SEM micrographs of 15 minutes-UVO treated red dyed cotton at 10g/L
stock formulation concentration
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.6 SEM micrographs of 5 minutes-UVO treated red dyed cotton at 100g/L
stock formulation concentration
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
137
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.7 SEM micrographs of 10 minutes-UVO treated red dyed cotton at 100g/L
stock formulation concentration
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.8 SEM micrographs of 15 minutes-UVO treated red dyed cotton at 100g/L
stock formulation concentration
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
138
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.9 SEM micrographs of 5 minutes-UVO treated red dyed cotton at 150g/L
stock formulation concentration
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.10 SEM micrographs of 10 minutes-UVO treated red dyed cotton at 150g/L
stock formulation concentration
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
139
(a) Dyed cotton
(b) Dry-rubbed (c) Wet-rubbed
Figure 5.11 SEM micrographs of 15 minutes-UVO treated red dyed cotton at 150g/L
stock formulation concentration
5.4 Conclusions
Cationizing the cotton fabrics prior to pigment dyeing improved the wet rub fastness
performance of the Matrix OSD dyeing system, but the other fastness properties
were in general unchanged.
It was apparent from the results of the crosslinker studies, that the colour fastness
was influenced by the crosslinking treatment which improved the link between
binder and fabrics. The pre-treatment approach appears more suitable to the
crosslinker application than the combined application method to improving the wet
rub fastness. Moreover, the crosslinker has almost no effect on wash fastness which
always remains at an acceptable performance level with most crosslinkers. In
comparison the Knittex MLF New pre-treatment at 40g/L offered the best option to
improve the colour fastness.
Chapter 5 Investigation into the Effect of Crosslinkers, Cationisation and Surface Modification on the Performance
of Matrix OSD Treatments
140
Unlike the benefits of UVO pre-treatment previously observed for other fabric
dyeing studies, in this study it was established that the pigment dyeing performance
was reduced after the sensitised photo-oxidation treatment. The reason for this
worsening of performance is unclear but it is perhaps due to changed fibre surface
chemistry not encouraging binding to the pigment dyeing system.
5.5 References
1. Lu, Y. and C. Q. Yang, Fabric Yellowing Caused by Citric Acid as a
Crosslinking Agent for Cotton, Textile Research Journal, 1999, 69(9):
p.685-690.
2. Waris, M., Effect of Crosslinking in Textile Pigment Printing and
Enhancement of Fastness Properties. Journal of the Chemical Society of
Pakistan, 2009, 31(1): p.145-150.
3. Wang, C. X. and Y. H. Zhang, Effect of Cationic Pre-treatment on Modified
Pigment Printing of Cotton. Materials Research Innovations, 2007, 11(1):
p.27-30.
4. Fang, K. J., Dyeing of Cationised Cotton Using Nanoscale Pigment
Dispersions. Coloration Technology, 2005, 121(6): p.325-328.
5. Bogle, M., Textile Dyes, Finishes, and Auxiliaries. Revised edn. 1977, New
York ; London, Garland Publishing. xiii, p.168.
6. Carr, C. M., Chemistry of the Textiles Industry, 1995, London: Blackie
Academic & Professional. xiii, p. 361.
7. Fritz, A. and Cant, J., Consumer Textiles, 1986, Melbourne: OUP.
8. Parfitt, M., Investigation into the Surface Chemistry of Cotton Fibres,
UMIST PhD Thesis, 2001.
9. Shao, J., Hawkyard, C. J., and Carr, C. M., Investigation into the Effect of
UV/ozone Treatments on the Dyeability and Printability of Wool, Journal of
the Society of Dyers and Colourists, 1997, 113(4): p.126-130.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
141
Chapter 6 Investigation into the Effect of
Flurocarbon Treatments on Matrix OSD
Treated Fabric Performance
6.1 Introduction
Fluorine-based finishing agents are an important class of effect chemicals used in
textiles because they can provide combined water and oil repellency without
impairing the air permeability or modifying the handle of textiles [1]. The benefit of
fluorocarbon finishes in imparting water and oil repellency to textile fabrics has
been studied previously but more recently new research has focused on plasma
polymerized fluorocarbon films [2-5]. However there are few studies relating colour
properties to fluorocarbon treatment, especially for pigment colouration.
In this chapter, the performance of fluorocarbon treatments on fabrics treated with
Matrix OSD system was investigated. Five different fluorocarbon treatments were
applied to the cotton fabrics either by pre-mixing with the pigment dyeing system or
as an after-treatment. Rub fastness, wash fastness, colour strength, abrasion
resistance, water/oil repellency, SEM and handle properties were examined in order
to establish the effects of fluorocarbon treatment on the pigment dyeing system. In
addition the Matrix OSD without softener, discussed in Chapter 4, was also assessed
in order to compare the water and oil repellency with that of the Matrix OSD system
with softener. The aim was to study the possible deleterious effect of the silicone
softener in the Matrix OSD binder on the fluorocarbon oil repellency treatment.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
142
6.2 Experimental Work
6.2.1 Materials
Fabrics 100% bleached plain cotton fabric, 191.5g/m2, was supplied by
Whaleys, Bradford, UK.
45/55 plain woven polycotton, 125 g/m2, were supplied by
Phoenix Calico, Stalybridge, UK.
Pigments Lyosperse red 2BN LIQ was supplied by Huntsman, UK.
Lyosperse yellow MR LIQ was supplied by Huntsman, UK.
Minerprint Blue B was supplied by Quality Colours, UK.
Binders Matrix OSD was supplied by Beyond Surface Technologies,
Switzerland.
Matrix OSD, without softener, was supplied by Beyond Surface
Technologies, Switzerland.
Wetting agent Alcopol 070 was supplied by Huntsman, UK.
Fluorocarbon
and related
chemicals
Scotchguard FC3548 was supplied by 3M, UK.
Shield F-01, Shield FRN-6 and Shield Extender FCD were
supplied by Beyond Surface Technologies, Switzerland.
Oleophobol 7713 and Hydrophobol XAN were supplied by
Huntsman, UK.
Rucoguard LAD was supplied by Rudolf Chemicals, UK.
6.2.2 Dyeing System
The modified Matrix OSD system discussed in Chapter 4 was used as the pigment
dyeing system in this study.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
143
6.2.3 Fluorocarbon Treatment
The cotton fabrics were treated by five different fluorocarbons:
Scotchguard FC3548;
Shield F-01 with Shield Extender FCD;
Shield FRN-6;
P2i fluorocarbon plasma polymerisation process;
Oleophobol 7713 with Hydrophobol XAN.
6.2.3.1 Scotchguard FC3548
The fabrics were treated by FC3548 by two different methods, incorporation into
dyeing formulation and as an after-treatment.
a. FC3548 was incorporated with pigment dyeing solution at a concentration of
5g/L, 10g/L, 30g/L and 50g/L. The subsequent dyeing procedure followed the
standard pigment dyeing system;
b. The pigment-dyed samples were after-treated by FC3548 at the same
concentrations as stated in Method a. The pigment-dyed samples were padded
with the FC3548 solution, squeezed to 80% w.p.u., dried at 110℃ for 3 minutes
and then cured at 180℃ for 1 minute.
6.2.3.2 Shield F-01 with Shield Extender FCD
Both pigment-dyed cotton and polycotton samples were after-treated by Shield F-01
with Shield extender FCD. Before Shield F-01 and Shield extender FCD were added
into the bath, the pH of the bath was adjusted to between 4.0 and 5.0 by acetic acid.
The concentrations of applied chemicals are presented in Table 6.1. The
pigment-dyed samples were padded with the treating solution at 80% w.p.u., dried at
110℃ for 3 minutes and cured at 170℃ for 1 minute.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
144
Table 6.1 Concentration of Shield F-01aftertreating system
Shield F-01 Conc.
g/L
Shield Extender FCD Conc.
g/L
Wetting agent Conc.
g/L
a 20 8 1
b 40 8 1
c 60 8 1
6.2.3.3 Shield FRN6
The pigment-dyed samples were after-treated by Shield FRN6 at 30g/L, 45g/L and
60g/L. The padding bath pH was adjusted between 4.0 and 5.0 by acetic acid.
Wetting agent was added at the concentration of 2g/L. The samples were padded
with the FRN6 solution at 80% w.p.u., dried at 110℃ for 3minutes and then cured
at 170℃ for 40 seconds.
6.2.3.4 P2i
The pigment-dyed samples were after-treated by P2i under three conditions:.
Process 1: ½monomer, flow 40 mTorr, Pw 40min;
Process 2: ½monomer, flow 40 mTorr, Pw 70min;
Process 3: Standard Process.
6.2.3.5 Oleophobol 7713 with Hydrophobol XAN
The fabrics were treated with the Oleophobol 7713 and Hydrophobol XAN
combination either by incorporation into the pigment dyeing formulation or as
after-treatment:
a. Oleophobol 7713 and Hydrophobol XAN were added into the pigment dyeing
solution. The concentrations of Oleophobol 7713 applied were 40g/L and 60g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
145
while the concentration of Hydrophobol XAN was 10g/L. Before they were
added into the dyeing solution, the bath pH was adjusted first to 5-7 by acetic
acid and the cotton fabrics were treated by the standard pigment dyeing system
process;
b. Alternatively after pigment dyeing, the samples were after-treated by
Oleophobol 7713 and Hydrophobol XAN at the same concentrations as stated in
Method a. The formulation pH was adjusted to between 5.0 and 7.0 using acetic
acid. After the bath was prepared, the pigment-dyed samples were padded at 80%
w.p.u., dried at 110℃ for 3 minutes and then cured at 170℃ for 90 second.
6.2.3.6 Rucoguard LAD and Oleophobol 7713
The plain cotton and red pigment dyed samples were treated with 7% owf
Rucoguard LAD and 8% owf Oleophobol 7713 with a liquor-to-goods ratio of 10:1
by exhaustion and padding method. The bath pH was adjusted to 4-5 by the addition
of acetic acid. The red samples were dyed by both Matrix OSD system and Matrix
OSD without softener system.
a. The plain cotton and red pigment dyed samples were treated with treating
solution at 20℃ for 20 minutes. Then the temperature was raised from 20℃ to
40℃ for another 20 minutes and kept at 40℃ for 20 minutes. After that, the
treated samples were dried at 110℃ for 90 seconds and cured at 160℃ for 1
minute.
b. The plain cotton and red pigment dyed samples were padded at 80% wet pick up,
dried at 110℃ for 90 seconds and cured at 160℃ for 1 minute.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
146
6.3 Results and Discussion
6.3.1 Effect of Scotchguard FC3548
Table 6.2 presents the fastness results of the combined Scotchguard FC3548/Matrix
OSD treated cotton fabric. Comparing the control 0g/L FC3548 treated fabric with
the combined FC3548 formulations indicates there was a clear beneficial effect on
the wet rub fastness while dry rub fastness and wash fastness remained relatively
unchanged. At the high concentrations of FC3548 the dry rub fastness was decreased,
especially for medium and dark colours (red and blue). Similarly although the
increasing concentration of FC3548 improved the wet rub fastness, it was reduced at
the highest application level, 50g/L. Therefore, the optimal treatment concentration
was 30g/L FC3548 and reflected the surface frictional properties of the film and its
cohesion and durability.
The effect of applying the fluorocarbon FC3548 on the fabric colour strength is
variable, Figure 6.1. The co-application of FC3548 improved colour yield at light
and dark colours (yellow and blue), whilst it decreased K/S at medium colour
strength (red). The nature of variability is uncertain but overall the colour change is
not perceived as a “problem”.
Table 6.3 presents the fastness results of red pigment dyed fabrics, which were
after-treated by FC3548. It is apparent that the Scotchguard FC3548 after-treatment
is beneficial in improving the wet and dry fastness performance and the optimal
application level would be 5g/L FC3548. In comparison to the pre-mixing
application, which offers “best” performance at 30g/L, the after-treatment method
appears to offer the better protection. Figure 6.2 illustrates the colour strength of the
control fabrics and red pigment dyed samples after-treated by FC3548. There
appears to be little colour change following the after-treatment.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
147
Table 6.4 presents the abrasion results for fabrics treated both by incorporating the
fluorocarbon into the pigment dyeing formulation and aftertreating the dyed fabrics
with fluorocarbon. The use of FC3548 decreased the number of rub cycles to two
yarns broken, the abrasion resistance reducing with the increase of the fluorocarbon
concentration. The number of rub cycles to failure for these two treatment methods
are almost the same.
Figures 6.3-6.14 shows the SEM micrographs of pigment red-dyed fabrics
aftertreated with FC3548 at increasing concentrations. It is evident that the
wet-rubbed areas are damaged more than dry-rubbed area which is the same as
observed with the micrographs of the control samples shown in Figures 4.14-4.16.
The effect of FC3548 was hardly observed from these micrographs, however,
compared with the reference images, Figure 4.14-4.16, the rubbed damage is less
and the surface is smoother, especially for wet rub fastness. This may be caused by
the repellent function imparted by FC3548.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
148
Table 6.2 Effect of varying FC3548 concentration within the pigment dyeing
formulation on the fastness of coloured cotton fabric
Formulation
Conc. g/L
FC3548
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow 10
0 5 4 5 5
5 4/5 4/5 5 5
10 4/5 4/5 5 5
30 4/5 4/5 5 5
50 4/5 4/5 5 5
Yellow 100
0 5 2/3 5 5
5 4/5 3 5 5
10 4/5 4 5 5
30 4/5 4/5 5 5
50 4 4 5 5
Yellow 150
0 4/5 2/3 4/5 5
5 4/5 3/4 5 5
10 4/5 4 5 5
30 4/5 4/5 5 5
50 4 4 5 5
Red 10
0 4/5 3/4 5 5
5 4/5 4/5 5 5
10 4/5 4/5 5 5
30 4/5 4/5 5 5
50 4 4/5 4/5 5
Red 100
0 4/5 2/3 4/5 5
5 4/5 4 5 5
10 3/4 3/4 4/5 4/5
30 4 4 5 5
50 3/4 3 4/5 5
Red 150
0 4/5 2 4/5 5
5 4/5 3/4 4/5 5
10 4 4 4/5 4/5
30 4 4 4/5 5
50 3 3 5 5
Blue 10
0 4/5 3 5 5
5 4/5 4/5 4/5 5
10 5 4/5 4/5 5
30 4 4/5 5 5
50 3/4 4 5 5
Blue 100
0 4/5 2/3 4/5 5
5 4/5 3 4/5 5
10 4/5 3/4 4/5 4/5
30 4/5 4 4/5 5
50 3 2/3 4 4/5
Blue 150
0 4/5 2 4/5 5
5 4 3/4 4/5 4/5
10 4 3 4/5 5
30 4 3/4 4/5 5
50 3 2 4 4/5
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
149
Table 6.3 Effect of varying FC3548 concentration on the fastness performance of red
pigment dyed cotton fabric
Table 6.4 Effect of FC3548 concentration on the Martindale Flat Abrasion
performance of pigment dyed cotton fabrics
Formulation Conc.
g/L
FC3548
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Red 10
0 4/5 3/4 5 5
5 4/5 4/5 5 5
10 4/5 4/5 4/5 5
30 4/5 4/5 5 5
50 4/5 4/5 5 5
Red 100
0 4/5 2/3 4/5 5
5 4/5 4 4/5 4/5
10 4/5 4 4/5 4/5
30 4/5 4/5 4/5 5
50 4 4 4/5 4/5
Red 150
0 4/5 2 4/5 5
5 4/5 3/4 4/5 4/5
10 4/5 3/4 4/5 4/5
30 4/5 3/4 4/5 5
50 4/5 3 4/5 4/5
Formulation Conc.
g/L
FC3548
g/L
Rubs
Incorporation Aftertreatment
Red 10
0 13500
5 11000 14500
10 12000 13500
30 8000 9000
50 8500 9000
Red 100
0 16500
5 11000 10500
10 9000 9000
30 9250 9000
50 10000 11000
Red 150
0 17850
5 10500 10000
10 12000 11000
30 10000 10000
50 8000 8000
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
150
Figure 6.1 Effect of varying FC3548 concentration on the colour strength of
increasing concentrations of pigment formulation applied to cotton fabric
Figure 6.2 Effect of varying FC3548 concentration on the colour strength of pigment
dyed cotton fabrics
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
151
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.3 SEM micrographs of 5g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.4 SEM micrographs of 10g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.5 SEM micrographs of 30g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.6 SEM micrographs of 50g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 10g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
152
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.7 SEM micrographs of 5g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.8 SEM micrographs of 10g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.9 SEM micrographs of 30g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.10 SEM micrographs of 50g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 100g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
153
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.11 SEM micrographs of 5g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 150g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.12 SEM micrographs of 10g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 150g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.13 SEM micrographs of 30g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 150g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.14 SEM micrographs of 50g/L FC3548 treated red-dyed cotton at a stock
formulation concentration of 150g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
154
6.3.2 Shield F-01 with Shield extender FCD
6.3.2.1 Treatments on Cotton
Table 6.5 shows the comparative fastness results of samples after-treated by F-01
and the control fabrics where the beneficial effects of the fluorocarbon are obvious
on the fabric’s wet rub fastness. However, increasing F-01 concentration does not
always improve wet rub fastness and when the F-01 concentration reached 60g/L,
rub fastness decreased, particularly for dark colours (blue). Even so, the wet rub
fastness was still better than the control fabrics. Although the fastness of the 20g/L
F-01 treated fabric was slightly lower than those of 40g/L samples for heavy shades,
20g/L probably still offers the best choice for application conditions due to the
consideration of cost.
The effect of the F-01 fluorocarbon aftertreatment on the fabric colour strength is
illustrated in Figure 6.15 and it is evident that in general the K/S value is marginally
increased. The colour difference may be a result of F-01 and extender surface film
altering the light interface interaction or less likely non-uniformity in application
during pigment dyeing.
The water and oil repellency of the pigment dyed fabrics treated with F-01 are
presented in Table 6.6 and indicate the water repellency remains fixed at W5, while
oil repellency has improved from OF at 20g/L to 3 at 60g/L. Nevertheless the
repellency performance is not particularly good and maybe related to the softener in
Matrix OSD.
Figures 6.16-6.24 show SEM micrographs of red-dyed fabrics aftertreated with F-01
at increasing concentrations. The micrographs indicate the wet-rubbed areas are
damaged more than dry-rubbed areas and the F-01 has a significant effect on the
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
155
visual abrasion damage with the rubbed damage less and the surface is smoother,
especially for wet rub fastness. This may be caused by the F-01 repellent finish
overlayer protecting the surface interface.
Table 6.5 Effect of varying F-01 concentration on the fastness of pigment dyed cotton
fabrics
Formulation Conc. g/L
F-01 g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow 10
0 5 4 5 5
20 4/5 4/5 5 5
40 4/5 4/5 5 5
60 4/5 4/5 5 5
Yellow 100
0 5 2/3 5 5
20 4/5 4/5 5 5
40 4 4/5 5 5
60 4/5 4/5 5 5
Yellow 150
0 4/5 2/3 4/5 5
20 4/5 4 5 5
40 4/5 4/5 4/5 5
60 4/5 4 5 5
Red 10
0 4/5 3/4 5 5
20 4/5 4/5 5 5
40 4/5 4/5 5 5
60 4/5 4/5 5 5
Red 100
0 4/5 2/3 4/5 5
20 4/5 4 5 5
40 4/5 4/5 5 5
60 4/5 4 5 5
Red 150
0 4/5 2 4/5 5
20 4/5 4/5 4/5 5
40 4 4/5 5 5
60 4 4 5 5
Blue 10
0 4/5 3 5 5
20 4/5 4/5 4/5 5
40 4/5 4/5 5 5
60 4/5 4/5 5 5
Blue 100
0 4/5 2/3 4/5 5
20 4/5 4 4/5 5
40 4 4 5 5
60 4/5 3/4 5 5
Blue 150
0 4/5 2 4/5 5
20 4/5 4 4/5 5
40 4/5 4/5 5 5
60 4/5 3 5 5
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
156
Table 6.6 Effect of varying F-01 concentration on the water and oil repellency of
pigment dyed cotton fabrics
Figure 6.15 Effect of varying F-01 concentration on the colour strength of pigment
dyed cotton fabrics
Formulation Conc. g/L F-01 g/L Water repellency Oil repellency
Yellow 10
20
W5 OF
Yellow 100 W5 OF
Yellow 150 W5 OF
Red 10
40
W5 2
Red 100 W5 2
Red 150 W5 2
Blue 10
60
W5 3
Blue 100 W5 3
Blue 150 W5 3
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
157
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.16 SEM micrographs of 20g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.17 SEM micrographs of 40g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.18 SEM micrographs of 60g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.19 SEM micrographs of 20g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 100g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
158
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.20 SEM micrographs of 40g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.21 SEM micrographs of 60g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.22 SEM micrographs of 20g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 150g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.23 SEM micrographs of 40g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 150g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
159
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.24 SEM micrographs of 60g/L F-01 treated red-dyed cotton at a stock
formulation concentration of 150g/L
6.3.2.2 Fluorocarbon Treatments on Polycotton Fabric
Polyester/cotton (Polycotton) fabric is the most common textile fabric blend and was
evaluated in this study in order to determine if the pigment dyeing system
functioned similarly on blends and whether fluorocarbon treatment could have a
similarly beneficial effect on blend performance. The fastness results of the
polycotton control fabric (F-01 concentration is 0g/L) and F-01 treated samples are
presented in Table 6.7, and indicated the performance of the control polycotton
fabrics are better than those observed for 100% cotton fabric. The wet rub fastness
was higher, while the dry rub fastness and wash fastness were maintained at an
excellent level. After the pigment dyed polycotton samples were treated with F-01,
the wet rub fastness significantly improved, the best application level being 20g/L.
Further as shown in Figure 6.25, it was apparent that a similar improvement in K/S
was observed, especially for blue-dyed samples, with increasing fluorocarbon
application.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
160
Table 6.7 Effect of varying F-01 concentration on the fastness of pigment dyed
polycotton fabrics
Formulation Conc.
g/L
F-01
g/L
Rub Fastness Wash Fastness
Dry Wet Colour Change Staining
Yellow 10
0 4/5 4/5 5 5
20 4/5 4/5 5 5
40 4/5 4/5 5 5
60 4/5 5 5 5
Yellow 100
0 4/5 4/5 5 5
20 4/5 4/5 5 5
40 4/5 4/5 5 5
60 4/5 4/5 5 5
Yellow 150
0 4/5 4/5 5 5
20 4/5 4/5 5 5
40 4 4/5 5 5
60 4/5 4/5 5 5
Red 10
0 4/5 4/5 5 5
20 4/5 4/5 5 5
40 4/5 4/5 5 5
60 4/5 4/5 5 5
Red 100
0 4/5 3 5 5
20 4/5 4 5 5
40 4 4/5 5 5
60 4 4/5 5 5
Red 150
0 4/5 3/4 5 5
20 4/5 4 5 5
40 4/5 4/5 5 5
60 4/5 4 5 5
Blue 10
0 4/5 4 5 5
20 4/5 4/5 5 5
40 4/5 4/5 5 5
60 4/5 4/5 5 5
Blue 100
0 4 3 4/5 5
20 4/5 4 5 5
40 4 4/5 5 5
60 4 4 4/5 5
Blue 150
0 4 3/4 4/5 5
20 4/5 4/5 5 5
40 4 4/5 5 5
60 4 4 4/5 5
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
161
Figure 6.25 Effect of varying F-01 concentration on the colour strength of pigment
dyed polycotton fabrics
6.3.3 Shield FRN6
Table 6.8 presents the fastness results of fabrics treated with Shield-FRN6 and the
control fabrics. The benefits of FRN6 after-treatment are clear on wet rub fastness,
however, increasing the FRN6 concentration did not increase the fastness further.
The optimal concentration therefore appears to be ~30g/L. The colour strength of the
fabrics treated by FRN6 appeared to be little different to the control fabrics, Figure
6.26.
As can be seen from Table 6.9, the flat abrasion resistance of the pigment dyed
fabrics was reduced after the application of FRN6 probably due to the reducing
fibre/fabric coating cohesion. Although increasing FRN6 concentration improved
abrasion resistance, the number of rub cycles to failure are still lower than these of
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
162
control fabrics.
Figures 6.27-6.29 present the selected KES-F results of the mechanical properties of
the blue pigment-dyed fabrics treated by FRN6. The results indicate that increasing
the pigment binder concentration from 10g/L to 150g/L increased the fabric rigidity
and that the subsequent fluorocarbon addition further increased fabric stiffness.
Table 6.10 illustrates the water and oil repellency results of the pigment dyed fabrics
after-treated by FRN6 fluorocarbon. It is clear that the repellency property is only
related to the FRN6 concentration, not the pigment formulation concentration. The
observed repellency performance is similar to F-01 treated fabrics in Section 6.3.2.1.
Water repellency is at the W5 level at all concentrations, while oil repellency is just
1 to 2 similar to the F-01 treatment. These repellency results are not adequate, and
may be caused by the softener in Matrix OSD binder.
Figures 6.30-6.38 show SEM micrographs of the blue-pigment dyed fabrics
after-treated by FRN6 at different concentrations and indicated the wet-rubbed areas
are more disrupted than the dry-rubbed areas. Compared with the images of the
control samples, the rubbing damage in the fluorocarbon treated material is lower
and the surface is smoother, this is especially obvious in the wet-rubbed fabric
micrograph. However, the level of damage increased with the increase of FRN6
concentration, suggesting the 30g/L application level was the best in terms of the
fastness performance. The FRN6 protected the fabric surface probably due to
lubrication of the interface.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
163
Table 6.8 Effect of varying FRN6 concentration on the fastness performance of
pigment dyed cotton fabric
Formulation Conc.
g/L
F6
g/L
Rub fastness Wash fastness
Dry Wet Colour change Staining
Yellow 10
0 5 4 5 5
30 4/5 4/5 5 5
45 4/5 4/5 5 5
60 4/5 4/5 5 5
Yellow 100
0 5 2/3 5 5
30 4/5 4 5 5
45 4/5 4 5 5
60 4/5 4/5 5 5
Yellow 150
0 4/5 2/3 4/5 5
30 4/5 4/5 5 5
45 4/5 4 4/5 5
60 4/5 3/4 5 5
Red 10
0 4/5 3/4 5 5
30 4/5 4/5 5 5
45 4/5 4/5 5 5
60 4/5 4/5 5 5
Red 100
0 4/5 2/3 4/5 5
30 4/5 3/4 4/5 5
45 4/5 4 4/5 5
60 4/5 3 5 5
Red 150
0 4/5 2 4/5 5
30 4/5 4 5 5
45 4/5 3/4 4/5 5
60 4/5 3/4 5 5
Blue 10
0 4/5 3 5 5
30 4/5 4/5 5 5
45 4/5 4/5 5 5
60 4/5 4 5 5
Blue 100
0 4/5 2/3 4/5 5
30 4/5 4 5 5
45 4/5 3/4 4/5 5
60 4/5 3 5 5
Blue 150
0 4/5 2 4/5 4/5
30 4/5 3/4 5 5
45 4 3 4/5 5
60 4/5 2/3 5 5
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
164
Table 6.9 Effect of varying FRN6 concentration on the flat abrasion of pigment dyed
cotton fabric
Table 6.10 Effect of varying FRN6 concentration on the water and oil repellency of
red pigment dyed cotton fabric
Formulation Conc. g/L F6 g/L Rubs
Red 10
0 13500
30 10250
45 10250
60 12500
Red 100
0 16500
30 12000
45 14500
60 15500
Red 150
0 17850
30 15000
45 15500
60 15750
Formulation Con. g/L F6 g/L Water repellency Oil repellency
10
30
W5 1
100 W5 1
150 W5 1
10
45
W5 2
100 W5 2
150 W5 2
10
60
W5 2
100 W5 2
150 W5 2
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
165
Figure 6.26 Effect of varying FRN6 concentration on the colour strength of pigment
dyed cotton fabric
Figure 6.27 Effect of varying FRN6 concentration on the bending stiffness of red
pigment dyed cotton fabric
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
166
Figure 6.28 Effect of varying FRN6 concentration on the shear stiffness of red
pigment dyed cotton fabric
Figure 6.29 Effect of varying FRN6 concentration on the shear hysteresis, 2HG5, of
red pigment dyed cotton fabric
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
167
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.30 SEM micrographs of 30g/L F6 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.31 SEM micrographs of 45g/L F6 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.32 SEM micrographs of 60g/L F6 treated red-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.33 SEM micrographs of 30g/L F6 treated red-dyed cotton at a stock
formulation concentration of 100g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
168
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.34 SEM micrographs of 45g/L F6 treated red-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.35 SEM micrographs of 60g/L F6 treated red-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.36 SEM micrographs of 30g/L F6 treated red-dyed cotton at a stock
formulation concentration of 150g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.37 SEM micrographs of 45g/L F6 treated red-dyed cotton at a stock
formulation concentration of 150g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
169
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.38 SEM micrographs of 60g/L F6 treated red-dyed cotton at a stock
formulation concentration of 150g/L
6.3.4 Effect of P2i dry plasma polymerisation treatments on pigment
dyed fabric fastness and liquid repellency performance
The P2i plasma polymerisation treatment improved the fabric fastness properties,
but not as significantly as samples treated by F-01 and FRN6, Table 6.11. In addition
the standard process, designated number 3, decreased the dry rub fastness,
particularly for medium and dark shades. Process 2 achieved better results than
process 1, but the differences were not large. The dry plasma polymerisation will
only deposit a 100-200nm thick layer while aqueous treatment will deposit a much
thicker layer so aiding in the observed wet and dry fastness improvements.
As shown in Figure 6.39, the colour strength almost stays at the same level as the
control samples.
Water and oil repellency results are presented in Table 6.12 and indicate before P2i
treatment, fabric water and oil repellency are all failed, however post-P2i treatment
repellency was imparted. Process 3 showed a greater effect than the other two
processes for water repellency while oil repellency levels are the same. After ISO
CO6 washing, both water and oil repellency were decreased and for water repellency,
the initial advantages of process 3 were not observed anymore. The reason for this
behaviour is not certain. After heat pressing, water repellency still was W5 but the
oil repellency recovered to the original value of 7, except for process 1 which
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
170
increased but not to the original value. Overall the water and oil repellency of the
P2i treatments are better than those of the fabrics treated by the aqueous F-01 and F6
treatments.
In contrast to the aqueous fluorocarbon treatments the fabric handle properties of P2i
treated fabrics, as determined by the KES-F analysis indicated the fabric rigidity was
reduced, Figures 6.40-6.42. The reduction in stiffness was due most likely to the
lubricating effect of the thin fluorocarbon surface layer.
Figures 6.43-6.51 illustrate the SEM analyses of the blue pigment-dyed fabrics
after-treated by P2i under different conditions. No obvious surface film was
apparent on the cotton fibres but it is evident that the wet-rubbed areas were more
disrupted than the dry-rubbed areas. Comparison between the control samples, and
the P2i treated materials indicated relatively little difference in the abrasion
behaviour. In addition, in comparison with the aqueous fluorocarbon treatments, the
rubbing damage was more obvious which correlated with the poorer observed rub
fastness.
Table 6.11 Effect of varying P2i treatment on the fastness of blue pigment dyed cotton
fabric
Formulation conc.
g/L P2i process
Rub fastness Wash fastness
Dry Wet Colour change Staining
10
Control 4/5 3 5 5
1 4/5 4 5 5
2 4/5 4 5 5
3 4/5 4 5 5
100
Control 4/5 2/3 4/5 5
1 4/5 3 4/5 5
2 4/5 3/4 4/5 5
3 3 3/4 4/5 5
150
Control 4/5 2 4/5 5
1 4/5 2/3 4/5 5
2 4/5 3 4/5 5
3 3/4 3/4 4/5 5
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
171
Table 6.12 Effect of varying P2i treatment on the water and oil repellency of blue
pigment dyed cotton fabric
a- P2i treated samples b- P2i treated/washed samples c- P2i treated/washed/heat pressed samples
*Heat pressed for 20s, washed by the ISO CO6 method
Figure 6.39 Effect of varying P2i treatment on the colour strength of blue pigment
dyed cotton fabric
Formulation
conc. g/L
P2i
process
Water repellency Oil repellency
a b c a b c
10
Control WF OF
1 W7 W5 W5 7 3 7
2 W9 W5 W5 7 4 7
3 W10 W6 W5 7 6 7
100
Control WF OF
1 W7 W5 W5 7 3 6
2 W8 W5 W5 7 4 7
3 W10 W5 W5 7 4 7
150
Control WF OF
1 W6 W5 W5 7 3 5
2 W7 W5 W5 7 4 7
3 W8 W5 W5 7 4 7
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
172
Figure 6.40 Effect of varying P2i treatment on the bending stiffness blue pigment
dyed cotton fabric
Figure 6.41 Effect of varying P2i treatment on the shear stiffness of blue pigment
dyed cotton fabric
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
173
Figure 6.42 Effect of varying P2i treatment on the shear hysteresis, 2HG5, of blue
pigment dyed cotton fabric
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.43 SEM micrographs of P2i process 1 treated blue-dyed cotton at a stock
formulation concentration of 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.44 SEM micrographs of P2i process 2 treated blue-dyed cotton at a stock
formulation concentration of 10g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
174
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.45 SEM micrographs of P2i process 3 treated blue-dyed cotton at a stock
formulation concentration 10g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.46 SEM micrographs of P2i process 1 treated blue-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.47 SEM micrographs of P2i process 2 treated blue-dyed cotton at a stock
formulation concentration of 100g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.48 SEM micrographs of P2i process 3 treated blue-dyed cotton at a stock
formulation concentration of 100g/L
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
175
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.49 SEM micrographs of P2i process 1 treated blue-dyed cotton at a stock
formulation concentration of 150g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.50 SEM micrographs of P2i process 2 treated blue-dyed cotton at a stock
formulation concentration of 150g/L
(a) Dyed cotton (b) Dry-rubbed (c) Wet-rubbed
Figure 6.51 SEM micrographs of P2i process 3 treated blue-dyed cotton at a stock
formulation concentration of 150g/L
6.3.5 Effect of Oleophobol on repellency performance
Examination of the performance of the Oleophobol treated fabrics indicated there is
relatively little difference between the two application methods for the fluorocarbons,
Tables 6.13-6.14 and Figure 6.52. Nevertheless it was apparent that there was a
small decrease in the dry rub fastness with increasing Oleophobol concentration
application, whilst the wet rub fastness increased at the 40g/L application level.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
176
Wash fastness remained excellent.
Interestingly there were some beneficial effects in colour strength with fluorocarbon
addition, Figure 6.52, although the improvement was reduced at 60g/L.
Table 6.14 indicated the water repellency was W5 for both pre-mixing and
after-treatment methods, while oil repellency is better when Oleophobol was mixed
into the pigment dyeing system possibly due to better orientation at the fibre surface.
In the wider context the repellency results were almost the same as those of F-01
and FRN6 treatments.
Table 6.13 Effect of varying Oleophobol concentration on the fastness of blue
pigment dyed cotton fabric
Treatment Formulation
Conc. g/L
Oleophobol
Conc. g/L
Rub Fastness Wash Fastness
Dry Wet Colour
Change Staining
Pre
-mixing
Blue 10
0 4/5 3 5 5
40 4/5 4 5 5
60 4 4/5 5 5
Blue 100
0 4/5 2/3 4/5 5
40 4 4 5 5
60 3/4 3/4 5 5
Blue 150
0 4/5 2 4/5 4/5
40 3/4 4/5 5 5
60 4 4 5 5
After
-treating
Blue 10
0 4/5 3 5 5
40 4 4/5 5 5
60 4/5 4/5 5 5
Blue 100
0 4/5 2/3 4/5 5
40 4 4 5 5
60 3/4 4 5 5
Blue 150
0 4/5 2 4/5 4/5
40 4 4 5 5
60 3/4 4 5 5
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
177
Table 6.14 Effect of varying Oleophobol concentration on the water and oil repellency
of blue pigment dyed cotton fabric
Treatment Formulation
Con. g/L
Oleophobol
Con. g/L
Water
Repellency
Oil
Repellency
Pre
-mixing
Blue 10
0 WF OF
40 W5 4
60 W5 4
Blue 100
0 WF OF
40 W5 4
60 W5 4
Blue 150
0 WF OF
40 W5 4
60 W5 4
After
-treating
Blue 10
0 WF OF
40 W5 2
60 W5 2
Blue 100
0 WF OF
40 W5 2
60 W5 2
Blue 150
0 WF OF
40 W5 2
60 W5 2
Figure 6.52 Effect of varying Oleophobol concentration on the colour strength of
blue pigment dyed cotton fabric (λmax=610nm)
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
178
6.3.6 Water/Oil Repellency Performance
6.3.6.1 Fluorocarbon Application to Undyed Cotton Fabric
Tables 6.15 and 6.16 show the results of the undyed cotton fabric treated with
fluorocarbons: Shield F-01 with Shield extender FCD; Shield FRN6; Oleophobol
7713 with Hydrophobol XAN. Surprisingly the ISO CO6 washing process had no
effect on water repellency, while it does reduce the oil repellency. However, oil
repellency is mainly recovered after heat pressing due to molecular re-orientation.
In general, the application of surface fluorocarbons improved flat abrasion resistance,
although the increased application levels tend to result in lesser improvements. For
F-01 and FRN6 treatment, the rub cycles to failure decreased with the increasing
fluorocarbon concentration, while in contrast the effect of increasing Oleophobol
concentration was higher abrasion resistance. Comparing the FRN6 results with
those following pigment dyeing, indicated non-pigment dyed materials had better
abrasion resistance, possibly due to better lubrication at the cellulosic interface.
Table 6.15 Water and oil repellency of cotton fabric treated with fluorocarbons and
subsequently washed and heat pressed
Fluorocarbon Concentration
g/L
Water repellency Oil repellency
a b c a b c
F-01
20 W5 W5 W5 2 OF 2
40 W5 W5 W5 4 OF 3
60 W5 W5 W5 4 OF 3
FRN6
30 W5 W5 W5 2 OF 2
45 W5 W5 W5 2 1 2
60 W5 W5 W5 3 OF 2
Oleophobol 40 W5 W5 W5 3 OF 3
60 W5 W5 W5 4 1 4
a- Fluorocarbon treated
b- Fluorocarbon treated and washed
c- Fluorocarbon treated, washed and heat pressed
OF- No oil repellency
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
179
Table 6.16 Abrasion resistance on cotton fabric treated by fluorocarbons
Fluorocarbon Concentration
g/L Rubs
Untreated cotton 0 14000
F-01
20 21500
40 19000
60 17000
FRN6
30 19000
45 16000
60 16000
Oleophobol 40 20000
60 24250
6.3.6.2 Matrix OSD System with No Softener
The comparison of the water and oil repellency of the red pigment dyed fabrics
treated by fluorocarbons, Table 6.17, indicated there was no repellency improvement
with the binder containing no silicone softener. Indeed the fabric water repellency
was relatively lower than the pigment dyeing system including softener.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
180
Table 6.17 Water and oil repellency of red pigment dyed cotton treated with F-01 and
FRN6 fluorocarbon finishes
Fluorocarbon
Conc. g/L
Formulation Conc.
g/L Water repellency Oil repellency
F-01
20
10 4 1
100 4 1
150 4 1
40
10 4 2
100 4 2
150 4 2
60
10 4 2
100 4 2
150 4 2
FRN6
30
10 4 2
100 4 2
150 4 2
45
10 4 2
100 4 2
150 4 2
60
10 4 3
100 4 3
150 4 3
6.3.6.3 Rucoguard LAD and Oleophobol 7713
In order to establish the effect of incorporating the softener into the Matrix OSD and
identify possible alternative better application conditions to improve the repellency
of the pigment dyeing system, exhaustion and padding application conditions were
examined for fluorocarbon finishes, Table 6.18. From the results it was apparent that
the exhaustion method was better for water and oil repellency performance. Though
it is uncertain why the fabric’s oil repellency was so poor for the padding application.
The Matrix OSD binder with softener offered decreased repellency properties.
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
181
Table 6.18 Water and oil repellency of plain untreated cotton and red pigment dyed
cotton treated by Rucoguard LAD and Oleophobol 7713 by exhaustion and padding
applications
Treatment methods Treated fabrics Water
repellency Oil repellency
Exhausting
Plain untreated cotton W8 5
R100* (with softener) W4 3
R100* (without softener) W8 5
Padding
Plain untreated cotton W0 OF
R100* (with softener) W4 OF
R100* (without softener) W4 OF
*R100 – Samples dyed by 100g/L red pigment dyeing formulation.
6.4 Conclusions
In general the effect of applying fluorocarbons to the pigment dyed fabrics had a
beneficial effect on wash fastness and wet rub fastness, while dry rub fastness was
marginally reduced at higher application levels. Comparing the fastness results on
samples treated by different fluorocarbons, the best conditions were found when the
dyed samples were after-treated by Shield F-01 with Shield extender FCD at 20g/L.
At this F-01 concentration, rub fastness and wash fastness were all at an excellent
level, above rating 4. Similarly with the polycotton fabric the benefits of F-01
treatment were apparent, particularly at the 20g/L application level. Although the dry
P2i plasma treatment cannot achieve the fastness results as the aqueous fluorocarbon
treatments, it still imparted improved water/oil repellency and fabric handle.
SEM analysis of the fabric damage due to the wet and dry rubbing indicated wet
abrasion was more damaging but that there was less damage in the samples treated
with the F-01 fluorocarbon.
When the fluorocarbon treatment was combined with the pigment dyeing systems,
Chapter 6 Investigation into the Effect of Flurocarbon Treatments on Matrix OSD Treated Fabric Performance
182
there was a deleterious effect on abrasion resistance and a reduced performance was
observed. However, in contrast when fluorocarbon was directly applied onto undyed
cotton fabrics, the abrasion resistance was improved, the Oleophobol treatment
giving the best result at the concentration of 60g/L.
Water and oil repellency of treated undyed cotton fabrics were the same as those on
coloured cotton. The only experiment which shows there was adverse effect related
to softener in the binder was the exhaustion application method with Oleophobol
7713 and Rucoguard LAD.
6.5 References
1. Celik, N., Icoglu, H. I., and Erdal, P., Effect of the Particle Size of
Fluorocarbon-based Finishing Agents on Fastness and Color Properties of
100% Cotton Knitted Fabric, Journal of the Textile Institute, 2011, 102(6):
p.483-490.
2. Grajeck, E. J. and Petersen, W. H., Oil and Water Repellent Fluorochemical
Finishes for Cotton, Textile Research Journal, 1962, 32(4): p.320-331.
3. Rijke, A. M., The Liquid Repellency of a Number of Fluorochemical
Finished Cotton Fabrics, Journal of Colloid Science, 1965, 20(3): p.205-216.
4. Vaswani, S., Koskinen, J., and Hess, D. W., Surface Modification of Paper
and Cellulose by Plasma-assisted Deposition of Fluorocarbon Films. Surface
& Coatings Technology, 2005, 195(2-3): p.121-129.
5. Von Gradowski, M., ToF-SIMS Characterisation of Ultra-thin Fluorinated
Carbon Plasma Polymer Films, Surface & Coatings Technology, 2005,
200(1-4): p.334-340.
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
183
Chapter 7 Investigation into the Effect of
Plasma Treatment on Matrix OSD Treated
Cotton Fabric
7.1 Introduction
Plasma techniques are attractive for several reasons in that they allow selective
modification of the substrate surface and the hydrophilic/hydrophobic nature of the
surface can be engineered by selecting the appropriate gas [1]. In modern textile
industry, selective removal of surface hydrophobic layers, enhancement of the
hydrophilicity and production of cotton with improved bleachability and dyeability
is increasingly important. Plasma-related techniques have been gradually used more
owing to their low impact on the environment and targeted surface modification.
Plasma research has also been focused on improving wettability, water repellency,
anti-soiling, soil release, printing, dyeing and some other finishing treatments of
textile fibres and fabrics [2-5]. In most of these studies, low-pressure plasma has
been mainly considered, but the plasma operation at low pressure is relatively
expensive, slower and can create technical difficulties. In recent years, treatments
using atmospheric pressure plasma jet were developed in order to offer process
flexibility and to create homogeneous plasma at low temperature [6-8].
In this chapter, helium, oxygen, nitrogen and argon were used as the plasma treating
gases. The samples treated were under the atmospheric pressure before and after
pigment dyeing. There is currently little research on the use of plasma system on
pigment dyeing systems. In this study, the interaction between the pigment dyeing
system and plasma treatments was studied.
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
184
7.2 Experimental work
7.2.1 Materials
Fabrics 100% bleached plain cotton fabric, 191.5g/m2, was supplied by
Whaleys, Bradford, UK.
Pigments Lyosperse red 2BN LIQ was supplied by Huntsman, UK.
Lyosperse yellow MR LIQ was supplied by Huntsman, UK.
Minerprint Blue B was supplied by Quality Colours, UK.
Binders Matrix OSD was supplied by Beyond Surface Technologies,
Switzerland.
Wetting agent Alcopol 070 was supplied by Huntsman, UK.
7.2.2 Dyeing System
The modified Matrix OSD system discussed in 4.2.4 was used as the pigment dyeing
system.
7.2.3 Plasma Treatment
7.2.3.1 Plasma pre-treatment
The undyed and pigment dyed cotton fabrics were treated under atmospheric
pressure using three different plasma gases at Enercon using a Plasma4™
atmospheric plasma surface treatment system:
a. 100% Helium;
b. 80% Helium with 20% oxygen, O2;
c. 80% Helium with 20% nitrogen, N2.
During the treatment, the line speed was 10m/min and power level was 1kW. After
plasma treating, the fabrics were blue- pigment- dyed following standard
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
185
procedures.
7.2.3.2 Plasma after-treatment
The cotton fabrics were pigment-dyed first and then divided into two parts. Half of
the fabrics were cured after the drying process and another half had no heat curing
procedure. These fabrics were then plasma treated under six different conditions on
both sides of cotton fabrics. The treatment conditions are illustrated in Table 7.1.
After plasma treatment, the uncured fabrics were cured under the normal conditions
for pigment dyeing system.
Table 7.1 Plasma treatment conditions
a b c d e f
Gas N2 Ar N2 Ar N2 Ar
Line
speed
(m/min)
10 10 10 10 7 7
Power
level
(kW)
0.5 0.5 1 1 1.1 1.1
Watt
density
90W/m2/
min
90W/m2/
min
180W/m2/
min
180W/m2/
min
285W/m2/
min
285W/m2/
min
7.3 Results and Discussion
7.3.1 Effect of Pre-treatment
The fastness results of the samples pre-treated with He/O2/N2 gases and the control
fabrics are shown in Table 7.2. Due to this plasma process preferentially only
treating one side of the cotton fabric, the rub fastness was tested for both sides: the
face and the reverse/back. Examination of the results indicated the dry rub fastness
decreased while the wet rub fastness was improved, although both changes were just
half scale. Interestingly, the back rub fastness was worse than the face side. In
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
186
addition after washing, the colour changed more after plasma treatment, but was still
not a significant change.
As can be seen in Figure 7.1, the colour strength was improved after treatment with
all plasma gases, although there was no clear trend.
Table 7.2 Effect of plasma pre-treatment on colour fastness
Formulation
Conc. g/L Gas
Rub Fastness Wash Fastness
Dry Wet Colour
Change Staining
face back face back
Blue10
Reference 4/5 3 4/5 5
He 4/5 4 3 2/3 4/5 5
He+O2 4 4 3 3 4/5 5
He+N2 4/5 4/5 4 4 4/5 5
Blue100
Reference 4/5 2/3 4/5 5
He 4/5 4 3 2/3 4 5
He+O2 4 3/4 2/3 2/3 4 5
He+N2 4 3/4 3 2/3 4 5
Blue150
Reference 4/5 2 4/5 5
He 4 3/4 3 3 4 5
He+O2 4 3/4 2/3 2/3 4 5
He+N2 4 4 2/3 2/3 4 5
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
187
Figure 7.1 Effect of plasma pre-treatment on colour strength (λmax=610nm)
7.3.2 Effect of Plasma After-treatment on the Fastness of Pigment
Dyed Fabrics
Tables 7.3-7.5 present the fastness results of heat cured pigment dyed fabrics with
plasma gas aftertreatment. It is evident that plasma treatment maintained the
excellent wash fastness and rub fastness was also either maintained or improved. In
particular the wet rub fastness was significantly improved. The plasma treatments
under the conditions of 0.5kW Ar, 1.0kW Ar and 1.0kW N2 achieved almost the
same effect but the 0.5kW Ar conditions were selected as the best condition based
on cost.
Further plasma after-treatments examined the effect of plasma treatment before the
final heat curing procedure of pigment dyeing, Tables 7.6-7.8. Similar to the
previous analysis the wash fastness and dry rub fastness remained almost unchanged
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
188
after plasma treatment. In contrast the wet rub fastness again was improved with the
1.0kW N2 plasma atmosphere offering the best treatment conditions. Comparing the
results of curing before plasma treatment and afterwards, the treatment with 1kW N2
(curing after plasma) achieved the better results.
The effect of plasma treatments on polymers is to create free radicals which can
either crosslink or react with oxygen or other reactive gases present [9, 10]. In this
study the effect of the argon and nitrogen plasma treatments was to increase rub
fastness which is probably due to creating a crosslinked outer surface layer that is
more resistant to abrasion and improves colour fastness. Similarly in plasma
treatment before heat curing the effect again was to increase rub fastness which is
probably due to creating a crosslinked outer surface layer that is more resistant to
abrasion and improves colour fastness. Previous studies examining the effect of
plasma processing on DMDHEU/acrylic acid treated cotton was to increase
crosslinking and improve crease recovery performance [11].
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
189
Table 7.3 Effect of plasma after-treatment on heat cured yellow pigment dyed fabric
fastness
Formulation
Conc. g/L Plasma treatment
Rub fastness Wash fastness
Dry Wet Colour Change Staining
Yellow 10
None 5 4 5 5
0.5kW Ar 5 4/5 5 5
0.5kW N2 4/5 4/5 5 5
1.0kW Ar 5 4/5 5 5
1.0kW N2 4/5 4/5 5 5
1.1kW Ar 4/5 4/5 5 5
1.1kW N2 4/5 4/5 5 5
Yellow 100
None 5 2/3 5 5
0.5kW Ar 4/5 3/4 4/5 5
0.5kW N2 4/5 3/4 5 5
1.0kW Ar 5 3/4 5 5
1.0kW N2 4/5 3/4 4/5 5
1.1kW Ar 4/5 3 5 5
1.1kW N2 4/5 3/4 5 5
Yellow 150
None 4/5 2/3 4/5 5
0.5kW Ar 4/5 3 4/5 5
0.5kW N2 4/5 2/3 5 5
1.0kW Ar 4/5 3/4 4/5 4/5
1.0kW N2 4/5 3/4 4/5 5
1.1kW Ar 4/5 3 5 5
1.1kW N2 4/5 2/3 5 5
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
190
Table 7.4 Effect of plasma after-treatment on heat cured red pigment dyed fabric
fastness
Formulation
Conc. g/L Plasma treatment
Rub fastness Wash fastness
Dry Wet Colour Change Staining
Red 10
None 4/5 3/4 5 5
0.5kW Ar 5 4/5 5 5
0.5kW N2 4/5 4/5 5 5
1.0kW Ar 5 4 5 5
1.0kW N2 4/5 4 5 5
1.1kW Ar 4/5 4/5 5 5
1.1kW N2 4/5 4/5 5 5
Red 100
None 4/5 2/3 4/5 5
0.5kW Ar 4/5 3/4 4/5 5
0.5kW N2 4/5 3 4/5 5
1.0kW Ar 5 3 4/5 4/5
1.0kW N2 4/5 3 4/5 4/5
1.1kW Ar 4/5 2/3 4/5 4/5
1.1kW N2 4/5 3 4/5 5
Red 150
None 4/5 2 4/5 5
0.5kW Ar 4/5 3 4/5 5
0.5kW N2 4/5 3 4/5 5
1.0kW Ar 4/5 3 4/5 4/5
1.0kW N2 4/5 3 4/5 4/5
1.1kW Ar 4/5 2/3 4/5 4/5
1.1kW N2 4/5 3 4/5 5
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
191
Table 7.5 Effect of plasma after-treatment on heat cured blue pigment dyed fabric
fastness
Formulation
Conc. g/L Plasma treatment
Rub fastness Wash fastness
Dry Wet Colour Change Staining
Blue 10
None 4/5 3 5 5
0.5kW Ar 4/5 4/5 5 5
0.5kW N2 4/5 4 5 5
1.0kW Ar 4/5 4 5 5
1.0kW N2 4/5 4 5 5
1.1kW Ar 4/5 4 5 5
1.1kW N2 4/5 4 5 5
Blue 100
None 4/5 2/3 4/5 5
0.5kW Ar 4/5 3 5 5
0.5kW N2 4/5 2/3 4/5 5
1.0kW Ar 4/5 3/4 4/5 5
1.0kW N2 4/5 3 4/5 4/5
1.1kW Ar 4/5 2/3 4/5 4/5
1.1kW N2 4/5 2/3 4/5 5
Blue 150
None 4/5 2 4/5 4/5
0.5kW Ar 4/5 2/3 4/5 5
0.5kW N2 4 2/3 4/5 5
1.0kW Ar 5 3 4/5 4/5
1.0kW N2 4/5 3 4/5 4/5
1.1kW Ar 4/5 2 4/5 4/5
1.1kW N2 4/5 2/3 4/5 5
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
192
Table 7.6 Effect of plasma after-treatment on uncured yellow pigment dyed fabric
followed by heat curing, fastness
Formulation
Conc. g/L Plasma treatment
Rub fastness Wash fastness
Dry Wet Colour Change Staining
Yellow 10
None 5 4 5 5
0.5kW Ar 4/5 4/5 5 5
0.5kW N2 4/5 4/5 5 5
1.0kW Ar 4/5 4/5 5 5
1.0kW N2 4/5 4/5 5 5
1.1kW Ar 4/5 4/5 5 5
1.1kW N2 4/5 4/5 5 5
Yellow 100
None 5 2/3 5 5
0.5kW Ar 4/5 3/4 5 5
0.5kW N2 4/5 4 5 5
1.0kW Ar 4/5 3 5 5
1.0kW N2 4/5 4 5 5
1.1kW Ar 4/5 4 5 5
1.1kW N2 4/5 3 5 5
Yellow 150
None 4/5 2/3 4/5 5
0.5kW Ar 4/5 3/4 5 5
0.5kW N2 4/5 3/4 5 5
1.0kW Ar 4/5 3/4 5 5
1.0kW N2 4/5 3/4 5 5
1.1kW Ar 4/5 3/4 4/5 5
1.1kW N2 4/5 3 5 5
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
193
Table 7.7 Effect of plasma after-treatment on uncured red pigment dyed fabric
followed by heat curing, fastness
Formulation
Conc. g/L Plasma treatment
Rub fastness Wash fastness
Dry Wet Colour Change Staining
Red 10
None 4/5 3/4 5 5
0.5kW Ar 4/5 4 5 5
0.5kW N2 4/5 4 5 5
1.0kW Ar 4/5 4 5 5
1.0kW N2 4/5 4 5 5
1.1kW Ar 4/5 4 4/5 5
1.1kW N2 4/5 4 5 5
Red 100
None 4/5 2/3 4/5 5
0.5kW Ar 4/5 3 4/5 4/5
0.5kW N2 4/5 3 5 4/5
1.0kW Ar 4/5 3 5 5
1.0kW N2 4/5 3/4 5 5
1.1kW Ar 4/5 3/4 4/5 5
1.1kW N2 4/5 2/3 5 4/5
Red 150
None 4/5 2 4/5 5
0.5kW Ar 4/5 3/4 4/5 4/5
0.5kW N2 4/5 3 4/5 4/5
1.0kW Ar 4/5 3 4/5 4/5
1.0kW N2 4/5 3/4 4/5 5
1.1kW Ar 4/5 3 4/5 5
1.1kW N2 4/5 2/3 4/5 4/5
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
194
Table 7.8 Effect of plasma after-treatment on uncured blue pigment dyed fabric
followed by heat curing, fastness
Formulation
Conc. g/L Plasma treatment
Rub fastness Wash fastness
Dry Wet Colour Change Staining
Blue 10
None 4/5 3 5 5
0.5kW Ar 4/5 4 5 5
0.5kW N2 4/5 4 4/5 5
1.0kW Ar 4/5 4 5 5
1.0kW N2 4/5 4 5 5
1.1kW Ar 4/5 4 5 5
1.1kW N2 4/5 4 4/5 5
Blue 100
None 4/5 2/3 4/5 5
0.5kW Ar 4/5 3/4 4/5 5
0.5kW N2 4/5 3/4 4/5 5
1.0kW Ar 4/5 3/4 4/5 5
1.0kW N2 4/5 3 4/5 5
1.1kW Ar 4/5 3/4 4/5 5
1.1kW N2 4 2/3 4/5 5
Blue 150
None 4/5 2 4/5 4/5
0.5kW Ar 4/5 2/3 4/5 5
0.5kW N2 4/5 2/3 4/5 5
1.0kW Ar 4/5 3/4 4/5 4/5
1.0kW N2 4/5 3/4 4/5 5
1.1kW Ar 4/5 3 4/5 5
1.1kW N2 4/5 2/3 4/5 5
7.4 Conclusions
Plasma pre-treatment prior to pigment dyeing has a marginal benefit on fastness
properties, and to some extent slightly decreased dry rub fastness. However, colour
strength was improved under all gas conditions. Mixed gas treatments (He & O2 and
He & N2) are better than the single gas treatment (He).
Plasma after-treatments, both Ar and N2 atmospheres, improved the fastness,
particularly wet fastness, when the curing procedure was applied before plasma
treatment.
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
195
Compared with the P2i treatment, Chapter 6, the fastness results were almost the
same, no matter which gaseous system was applied. However, the P2i treatment
showed better colour strength and fabric properties. Accordingly this research
direction should be an interesting area for the future work of plasma treatment even
though the atmospheric plasma treatment offers more opportunity for continuous
treatment.
7.5 References
1. Zeng, F., Textiles., Investigation into the Colouration of Polypropylene,
UMIST PhD Thesis, 2002.
2. Özdogan, E., A New Approach for Dyeability of Cotton Fabrics by Different
Plasma Polymerisation Methods, Coloration Technology, 2002, 118(3):
p.100-103.
3. Okuno, T., Yasuda, T., and Yasuda, H., Effect of Crystallinity of PET and
Nylon-66 Fibers on Plasma-etching and Dyeability Characteristics, Textile
Research Journal, 1992, 62(8): p.474-480.
4. Sarmadi, A. M. and Kwon, Y. A., Improved Water Repellency and Surface
Dyeing of Polyester Fabrics by Plasma Treatment, Textile Chemist and
Colorist, 1993, 25(12): p.33-40.
5. Wakida, T., Surface Characteristics of Wool and Poly (ethylene terephthalate)
Fabrics and Film Treated with Low-Temperature Plasma Under Atmospheric
Pressure, Textile Research Journal, 1993, 63(8): p.433-438.
6. Tian, L. Q., Helium/oxygen Atmospheric Pressure Plasma Jet Treatment for
Hydrophilicity Improvement of Grey Cotton Knitted Fabric, Applied Surface
Science, 2011, 257(16): p.7113-7118.
7. Peng, S., Influence of Argon/oxygen Atmospheric Dielectric Barrier
Discharge Treatment on Desizing and Scouring of Poly (vinyl alcohol) on
Cotton Fabrics, Applied Surface Science, 2009, 255(23): p.9458-9462.
Chapter 7 Investigation into the Effect of Plasma Treatment on Matrix OSD Treated Cotton Fabric
196
8. Mitchell, R., Carr, C. M., Parfitt, M., Vickerman, J. C. and Jones, C., Surface
Chemical Analysis of Raw Cotton Fibres and Associated Materials, Cellulose,
2005, 12(6): p.629-639.
9. Sparavigna, A., Plasma Treatment Advantages for Textiles, arXiv:
0801.3727 [physics.pop-ph], 2008.
10. Morent, R., De Geyter, N., Verschuren, J., De Clerck, K., Kiekens, P. and
Leys, C., Surface and Coatings Technology, 2008, 202: p.3427-3449.
11. Chen, C. C., Chen, J. C. and Yao, W. H., Argon Plasma Treatment for
Improving the Physical Properties of Crosslinked Cotton Fabrics with
Dimethyloldihydroxyethyleneurea-Acrylic Acid, Textile Research Journal,
2010, 80 (8): p.675-682.
Chapter 8 Surface Analysis
197
Chapter 8 Surface Analysis
8.1 XPS Analysis of Blue Pigment-dyed Cotton Treated
with Fluorocarbons
Since the colour fastness performance of the pigment dyed fabrics appeared to be
strongly influenced by the surface interface the surface sensitive techniques, XPS
and ToF-SIMS were used to characterise the outer region and potentially provide
insight in how to improve the durability of colourant/polymer binder layer.
Examination of the XP spectrum of untreated cotton fabric indicated the presence of
mainly carbon, oxygen and traces of nitrogen, Table 8.1. The C (1s) spectrum of the
untreated cotton, Figure 8.1, shows the presence of a number of carbon species
present in the outer 10nm as indicated by the characteristic binding energies:
285.0eV C-C, C-H;
286.6eV C-OH;
288.0eV C=O; O-C-O;
289.0eV HO-C=O;
If the cotton fibre surface was pure cellulose it would be expected that only two
carbon spectral features would be observed, that is the C-OH and O-C-O species
with relative intensities of 5:1. However it is evident that significant
hydrocarbon-based material, at a binding energy of 285.0eV, and carboxyl species,
at 289.0eV, were present at the fibre surface. In addition the expected C-O and
O-C-O species ratio of 5:1 was not apparent suggesting the peak intensity at
288.0eV has increased due to the presence of C=O species. The scouring and
bleaching of cotton fabric is known to oxidise the fibre surface giving rise to
oxycellulose and previous surface analysis of cotton has reported that not all the
cotton wax was removed from the fibre surface following these wet preparation
processes [1, 2].
Chapter 8 Surface Analysis
198
Application of the Matrix OSD binder with increasing levels of pigment to the
untreated cotton fabric results in an concomitant increase in the N (1s) spectral peak
intensity related to the organic pigment, Table 8.1. Figures 8.1-8.4 present the C (1s)
spectra of the blue pigment dyed cotton fabrics and it is evident at the 10g/L
application level that there is an obvious difference in the C (1s) spectral component
intensities at the 10g/L application level. However at 100 and 150g/L levels the
spectral profile is similar to the original cotton surface composition and probably
reflects the increased level of pigment and its similar elemental composition to the
cotton surface.
The C (1s), O (1s), F (1s) and N (1s) atomic compositions of the blue-dyed fabrics
after-treated with the F-01 and F6 fluorocarbons and P2i plasma polymerisation
treatments are tabulated in Table 8.1 and indicate the obvious presence of surface
fluorine associated with the fluorocarbons. Examination of the C (1s) spectra of the
F-01 and F6 fluorocarbon treated cotton fabrics indicated the presence of peak
intensity at 291.1eV and 293.4eV which can be assigned to CF2 and CF3 species.
With both fluorocarbons the CF2 component is largest component reflecting their
greater contribution to the C6 and C8 perfluoro chains. The F-01 and F6
fluorocarbons are based on F8 and F6 perfluoro chains but the observed XPS
fluorine % atomic compositions are surprisingly similar and probably explains why
the water and oil repellency of the F-01 and FRN6 treated fabrics are similar, as
stated in Chapter 6.
The effect of ISO CO6 washing the fluorocarbon treated 150g/L pigment dyed fabric
was to reduce the intensity of F (1s) photoelectron emission due to polymer
re-orientation and the perfluoro chains being “buried” in the sub-surface, Table 8.1,
Figures 8.11 and 8.19. However the subsequent heat pressing re-orientated the
fluorocarbon surface polymer almost back to its original spectral intensity and
Chapter 8 Surface Analysis
199
regenerated the liquid repellency, Table 8.1, Figures 8.12 and 8.20.
Table 8.1 XPS surface elemental composition of blue pigment dyed cotton fabric
treated with fluorocarbons
Pigment
Formulation
Conc. g/L
Fluorocarbon
Type
Fluorocarbon
Conc. g/L
Atomic Composition %
C1s O1s F1s N1s
Untreated
Cotton Control 1 0 78.8 20.9 ND 0.3
Blue 10
Control 0 69.6 28.8 ND 1.3
F-01 40 49.8 9.1 40.9 0.2
60 49.6 7.5 42.7 0.2
FRN6 45 50.9 8.8 40.2 0.1
60 49.8 8.5 41.6 0.1
P2i
Process1 46.9 7.4 45.6 0.2
Process2 45.4 6.1 48.4 0.05
Process3 44.5 6.1 49.4 0.04
Blue 100
Control 2 0 78.8 19.5 ND 1.8
F-01 40 50.4 7.1 42.4 0.1
60 49.9 7.1 42.9 0.2
FRN6 45 51.4 9.2 39.3 0.1
60 49.4 7.7 42.8 0.01
P2i
Process1 47.4 7.6 44.9 0.2
Process2 44.6 5.9 49.4 0.1
Process3 44.2 6.1 49.7 0.0
Blue 150
Control 3 0 78.9 19.1 ND 2.0
F-01
40 49.2 7.7 42.7 0.4
60 51.6 6.9 41.3 0.2
601 59.1 9.9 30.5 0.5
602 47.7 6.8 45.3 0.2
FRN6
45 49.7 8.6 41.5 0.2
60 49.9 8.2 41.7 0.2
601 55.5 10.1 34.1 0.3
602 50.3 8.0 41.5 0.2
P2i
Process1 48.0 8.2 43.5 0.3
Process2 45.2 6.1 48.7 0.01
Process3 45.2 6.2 48.6 0.1
Process31 53.2 14.8 31.7 0.3
Process32 49.4 11.9 38.4 0.3
1- Washed
2- Washed and heat pressed
ND- Not detected
Chapter 8 Surface Analysis
200
Figure 8.1 C (1s) XP spectrum of untreated cotton fabric
Figure 8.2 C (1s) XP spectrum of 10g/L blue dyed cotton fabric
Figure 8.3 C (1s) XP spectrum of 100g/L blue dyed cotton fabric
C 1s/6
C 1
s
x 102
10
20
30
40
50In
tensi
ty
300 296 292 288 284 280 276
Bi ndi ng E nergy (eV)
C 1s/14
C 1
s
x 102
5
10
15
20
25
30
35
40
45
Inte
nsi
ty
300 296 292 288 284 280 276
Bi ndi ng E nergy (eV)
C 1s/22
C 1
s
x 102
10
20
30
40
50
60
Inte
nsi
ty
296 292 288 284 280 276
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
201
Figure 8.4 C (1s) XP spectrum of 150g/L blue dyed cotton fabric
Figure 8.5 C (1s) XP spectrum of 10g/L blue dyed cotton fabric treated with 40g/L
F-01
Figure 8.6 C (1s) XP spectrum of 100g/L blue dyed cotton fabric treated with 40g/L
F-01
C 1s/30
C 1
s
x 102
10
20
30
40
50
60In
tensi
ty
300 296 292 288 284 280 276
Bi ndi ng E nergy (eV)
C 1s/6
C 1s
C 1
s
x 102
2
4
6
8
10
12
14
16
18
20
22
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/14
C 1s
C 1s
C 1s
C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
202
Figure 8.7 C (1s) XP spectrum of 150g/L blue dyed cotton fabric treated with 40g/L
F-01
Figure 8.8 C (1s) XP spectrum of 10g/L blue dyed cotton fabric treated with 60g/L
F-01
Figure 8.9 C (1s) XP spectrum of 100g/L blue dyed cotton fabric treated with 60g/L
F-01
C 1s/22
C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/30
C 1sC 1s
C 1
s
x 102
5
10
15
20
25
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/38
C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
203
Figure 8.10 C (1s) XP spectrum of 150g/L blue dyed cotton fabric treated with 60g/L
F-01
Figure 8.11 C (1s) XP spectrum of washed 150g/L blue dyed cotton fabric treated with
60g/L F-01
Figure 8.12 C (1s) XP spectrum of washed & heat pressed 150g/L blue dyed cotton
fabric treated with 60g/L F-01
C 1s/46
C 1sC 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/38
C 1
s
x 102
5
10
15
20
25
30
35
40
45
Inte
nsi
ty
296 292 288 284 280 276
Bi ndi ng E nergy (eV)
C 1s/46
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
296 292 288 284 280 276
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
204
Figure 8.13 C (1s) XP spectrum of 10g/L blue dyed cotton fabric treated with 45g/L
FRN6
Figure 8.14 C (1s) XP spectrum of 100g/L blue dyed cotton fabric treated with 45g/L
FRN6
Figure 8.15 C (1s) XP spectrum of 150g/L blue dyed cotton fabric treated with 45g/L
FRN6
C 1s/54
C 1s
C 1s
C 1
s
x 102
2
4
6
8
10
12
14
16
18
20
22
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/62
C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/70
C 1s C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
205
Figure 8.16 C (1s) XP spectrum of 10g/L blue dyed cotton fabric treated with 60g/L
FRN6
Figure 8.17 C (1s) XP spectrum of 100g/L blue dyed cotton fabric treated with 60g/L
FRN6
Figure 8.18 C (1s) XP spectrum of 150g/L blue dyed cotton fabric treated with 60g/L
FRN6
C 1s/78
C 1sC 1s
C 1
s
x 102
5
10
15
20
25
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/86
C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/94
C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
206
Figure 8.19 C (1s) XP spectrum of washed 150g/L blue dyed cotton fabric treated with
60g/L FRN6
Figure 8.20 C (1s) XP spectrum of washed & heat pressed 150g/L blue dyed cotton
fabric treated with 60g/L FRN6
The high-resolution scans of the C (1s) region for fabrics treated in the P2i plasma
polymerisation chamber are presented in Figures 8.21-8.31. The CF3 fluorocarbon
species are present in higher concentration than the aqueous fluorocarbon polymer
chains and the P2i surface fluorine concentration was higher than the aqueous
fluorocarbon treatments. This spectral feature was more obvious with the fabrics
treated by the P2i Processes 2 and 3.
Similar to the F-01 and FRN6 surface treatments the effect of washing the P2i
treated fabrics was to reduce the surface fluorine which was only partially recovered
after heat pressing. This partial recovery was a reflection of the nature of the
C 1s/54
C 1s
C 1
s
x 102
5
10
15
20
25
30
35
40
Inte
nsi
ty
296 292 288 284 280 276
Bi ndi ng E nergy (eV)
C 1s/62
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
296 292 288 284 280 276
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
207
fluoropolymer and the absence of a hydrophilic copolymer component. As identified
in Chapter 6, the water and oil repellency of fabrics treated with the P2i system was
higher than those of fabrics treated with the F-01 and FRN6 fluorocarbons and
maintained a good repellency levels even after washing, especially for Process 2 and
3 treatments. However subsequent hot pressing did not recover the original water
repellency performance but heat pressing did return the original oil repellency levels.
The nature of this difference in behaviour is unclear at present.
Figure 8.21 C (1s) XP spectrum of 10g/L blue dyed cotton treated with P2i Process 1
Figure 8.22 C (1s) XP spectrum of 100g/L blue dyed cotton treated with P2i Process 1
C 1s/102
C 1s
C 1s
C 1
s
x 102
5
10
15
20
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/110
C 1s
C 1s
C 1s
C 1s C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
208
Figure 8.23 C (1s) XP spectrum of 150g/L blue dyed cotton treated with P2i Process 1
Figure 8.24 C (1s) XP spectrum of 10g/L blue dyed cotton treated with P2i Process 2
Figure 8.25 C (1s) XP spectrum of 100g/L blue dyed cotton treated with P2i Process 2
C 1s/118
C 1s
C 1s
C 1s
C 1s
C 1
s
x 102
5
10
15
20
25In
tensi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/126
C 1
s
x 102
5
10
15
20
25
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/134
C 1s
C 1s
C 1s
C 1sC 1s
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
209
Figure 8.26 C (1s) XP spectrum of 150g/L blue dyed cotton treated with P2i Process 2
Figure 8.27 C (1s) XP spectrum of 10g/L blue dyed cotton treated with P2i Process 3
Figure 8.28 C (1s) XP spectrum of 100g/L blue dyed cotton treated with P2i Process 3
C 1s/142
C 1s
C 1sC 1s C 1s
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/150
C 1s
C 1s
C 1s
C 1s
C 1
s
x 102
5
10
15
20
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/158
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
210
Figure 8.29 C (1s) XP spectrum of 150g/L blue dyed cotton treated with P2i Process 3
Figure 8.30 C (1s) XP spectrum of washed 150g/L blue dyed cotton treated with P2i
Process 3
Figure 8.31 C (1s) XP spectrum of washed & heat pressed 150g/L blue dyed cotton
treated with P2i Process 3
C 1s/166
C 1s
C 1s
C 1sC 1s
C 1s
C 1
s
x 102
5
10
15
20
25
30In
tensi
ty
300 295 290 285 280 275 270
Bi ndi ng E nergy (eV)
C 1s/70
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
296 292 288 284 280 276
Bi ndi ng E nergy (eV)
C 1s/78
C 1s
C 1
s
x 102
5
10
15
20
25
30
Inte
nsi
ty
296 292 288 284 280 276
Bi ndi ng E nergy (eV)
Chapter 8 Surface Analysis
211
8.2 ToF-SIMS Analysis of Blue Pigment-dyed Cotton
Treated with Fluorocarbon Finishes
Whilst the XPS technique can provide information about the fibre surface elemental
composition, oxidation state and chemical environment, the complementary
ToF-SIMS analysis is beneficial in that the molecular nature of the surface species
can also be characterised [1]. An important component of the study was the effect of
laundering with standard ECE detergent and the surfactant adsorption on the Matrix
OSD and fluorocarbon treated Matrix OSD fabrics. Therefore the ECE detergent
was first characterised in order to assign subsequent binding of surfactant
constituents.
8.2.1 ECE Detergent with Phosphates
The positive ion spectra show the presence of non-ionic surfactants which are a
mixture of C12-C18 fatty alcohol ethoxymers, Table 8.2 and Figures 8.33-8.34, but in
general the C16 and C18 components were the dominant species. Examination of the
relative peak intensities in the positive ion spectra indicated that the sociated C18EO7
and C18EO8 species were present in the highest concentration in the powder
formulation.
The negative ion spectra showed that the C11 alkyl benzene sulphonate was present
in the greatest concentration, Figure 8.34(c). The typical composition of the linear
alkyl benzene sulphonates (LAS) in the washing formulation is as Figure 8.32 [2]:
m/z = 297-, (conc. <1%)
m/z = 311
-, (conc. ~38%)
m/z = 325-, (conc. ~32%) m/z = 339
-, (conc. ~ 18%)
Figure 8.32 Typical composition of the linear alkyl benzene sulphonates (LAS)
Chapter 8 Surface Analysis
212
Examination of the ToF-SIMS negative ion spectra indicates the C11 component was
present in the highest concentration. Other obvious negative ion species evident are
SO3 ,̄ HSO4 ̄and NaSO4 ̄at m/z = 80-, 96
- and 119
-, respectively. Weak signals due
to the C18, 20 and 22 sodium soaps at m/z = 283-, 327
- and 371
-, respectively, were
also observed.
Table 8.2 ToF-SIMS Fatty alcohol ethoxylates ion assignments
C12H25-[CH2CH2O]n-OH/Na+
N 1 2 3 4 5 6 7 8 9 10 11
mass/z 253 297 341 385 429 473 517 561 605 649 693
C13H27-[CH2CH2O]n-OH/Na+
N 1 2 3 4 5 6 7 8 9 10 11
mass/z 267 311 355 399 443 487 531 575 619 663 707
C14H29-[CH2CH2O]n-OH/Na+
N 1 2 3 4 5 6 7 8 9 10 11
mass/z 281 325 369 413 457 501 545 589 633 677 721
C15H31-[CH2CH2O]n-OH/Na+
N 1 2 3 4 5 6 7 8 9 10 11
mass/z 295 339 383 427 471 515 559 603 647 691 735
N 12 13 14 15 16 17
mass/z 779 823 867 911 955 999
C16H33-[CH2CH2O]n-OH/Na+
N 1 2 3 4 5 6 7 8 9 10 11
mass/z 309 353 397 441 485 529 573 617 661 705 749
N 12 13 14 15 16
mass/z 793 837 881 925 969
C17H35-[CH2CH2O]n-OH/Na+
N 1 2 3 4 5 6 7 8 9 10 11
mass/z 323 367 411 455 499 543 587 631 675 719 763
N 12 13 14 15 16
mass/z 807 851 895 939 983
C18H37-[CH2CH2O]n-OH/Na+
N 1 2 3 4 5 6 7 8 9 10 11
mass/z 337 381 425 469 513 557 601 645 689 733 777
N 12 13 14 15 16
mass/z 821 865 909 953 997
Chapter 8 Surface Analysis
213
(a)
(b)
(c)
(d)
Figure 8.33 (a)-(d) ToF-SIMS positive ion spectra of ECE detergent powder
Chapter 8 Surface Analysis
214
(a)
(b)
(c)
Figure 8.34 (a)-(c) ToF-SIMS negative ion spectra of ECE detergent powder
8.2.2 Matrix OSD Binder Applied to Cotton Fabric
The ToF-SIMS spectra of untreated cotton are shown in Figure 8.36, which indicate
the presence of a complex mixture of chemical species at the cotton fibre surface. The
cellulosic signals can be observed, for example the cellulose-specific m/z 71-, 87
-,
113- and 221
-, Figure 8.36(c)-(d).
CH2=CHCOO-
HOCH=CHCOO-
m/z = 71- m/z=87
-
m/z = 113- m/z = 221
-
Figure 8.35 Cellulose-specific
Chapter 8 Surface Analysis
215
(a) positive ion mode
(b) positive ion mode
(c) negative ion mode
(d) negative ion mode
(e) negative ion mode
Figure 8.36 ToF-SIMS spectra of untreated cotton fabric
Chapter 8 Surface Analysis
216
The “clean” cotton fabric also has residues from the scouring detergent where alkyl
benzene sulphonates were present in the negative ion spectrum at m/z = 311-, 325
-
and 339- and alkyl sulphates (C12H25OSO3
-, C14H29OSO3
-, C16H33OSO3
- and
C18H37OSO3-) present at m/z = 265, 309, 353 and 397
-.
The ToF-SIMS spectra of the cotton fabric treated with 135g/L of Matrix OSD
binder and the related washed binder treated cotton fabric are presented in Figures
8.37-8.40. The binder is reported to be a polyacrylate derivative with a siloxane
softener incorporated therefore the typical polyacrylate signals and PDMS
(polydimethylsiloxane) signals are presented in Tables 8.3-8.5. It is evident from the
spectra that the silicone is clearly present at the binder surface and to some extent
complicates the assignment of the binder species, nevertheless typical ethyl acrylate
species can be observed in both the positive and negative ion spectra, Figure 8.37
and 8.38.
Table 8.3 Polyacrylate positive ion assignments
m/z
CH3
+ 15
+
C2H5
+ 29
+
C3H5
+ 41
+
CH2=CH-C≡O+ 55
+
C4H9
+ 57
+
+O≡C-O-CH3 59
+
+O≡C-O-C2H5 73
+
+O≡C-O-C4H9 101
+
+CH2–CH2-COO-C2H5 101
+
+CH2–CH2-CH2-COO-CH3 101
+
+CH2–CH2-CH2-COO-C2H5 115
+
Chapter 8 Surface Analysis
217
Table 8.4 Poly(acrylate) negative ion assignments
m/z
-CH2–COO-CH3 73-
-CH2–COO-C4H9 101-
-CH2–CH2-COO-C2H5 101-
-CH2–CH2-COO-C4H9 115-
Table 8.5 PDMS (-[(CH3)2SiO]n-) ion assignments
m/z
Si+ 28
+
SiH+ 29
+
CH3Si+ 43
+
(CH3)2SiH+ 59
+
(CH3)3Si+ 73
+
[(CH3)3Si2O2]+ 133
+
(CH3)3SiOSi(CH3)2
+ 147
+
[(CH3)5Si3O3]+ 207
+
(CH3)3SiOSi(CH3)2OSi(CH3)2
+ 221
+
(CH3)3Si[OSi(CH3)2]2OSiO+ 281
+
Si- 28
-
SiH- 29
-
CH3SiO- 59
-
OSiO- 60
-
OSi(CH3)O- 75
-
[(CH3)Si2O3]- 119
-
OSi(CH3)2OSi(CH3)O- 149
-
OSi(CH3)2OSi(CH3)2OSi(CH3)O- 223
-
Chapter 8 Surface Analysis
218
(a)
(b)
(c)
(d)
(e)
Figure 8.37 (a)-(e) ToF-SIMS positive ion spectra of Matrix OSD binder applied to
cotton fabric
Chapter 8 Surface Analysis
219
(a)
(b)
(c)
Figure 8.38 (a)-(c) ToF-SIMS negative ion spectra of Matrix OSD binder applied to
cotton fabric
After washing, there are significant changes in the ToF-SIMS spectral intensity;
particularly with the signal at 23+ associated with Na
+ dominating the positive ion
spectrum, Figure 8.37(a). In semi-quantifying the surface sodium level, an internal
standard peak, 41+ (C3H5
+) can be used as the indicator. The ratio of sodium is
calculated: 23+/41
+ ratio of unwashed samples is 0.63, while the ratio of washed
samples is 2.1. The polyacrylate and PDMS signals are all relatively reduced by
washing as well.
In Section 8.2.1, the ECE detergent power was analysed by ToF-SIMS and found to
Chapter 8 Surface Analysis
220
contain a mixture of C12-C18 fatty alcohol ethoxylates with the C18EO7/8 fatty
alcohol ethoxylates predominating. Examination of the positive ion spectrum of
unwashed samples at higher masses also showed the presence of fatty alcohol
ethoxylates, Figure 8.37(d)-(e). That is probably due to their presence in the binder
system. After washing, the intensity of fatty alcohol ethoxylates was lowered with
the main peak intensity arising due to the C18EO3-7, Figure 8.40 (c)-(d), due to their
lower water solubility and greater affinity for the binder.
The ToF-SIMS negative ion spectrum of washed Matrix OSD binder treated fabrics
indicate the presence of alkyl benzene sulphonates adsorbed onto the fibre surface,
Figures 8.41(a), with the intensity of the more hydrophobic LAS “sticking” more
than the shorter chain more water soluble derivatives:
>
>
Figure 8.39 The intensity of the more hydrophobic LAS
Chapter 8 Surface Analysis
221
(a)
(b)
(c)
(d)
(e)
Figure 8.40 (a)-(e) ToF-SIMS positive ion spectra of ISO CO6 washed cotton fabric
with applied Matrix OSD Binder
Chapter 8 Surface Analysis
222
(a)
(b)
(c)
Figure 8.41 (a)-(c) ToF-SIMS negative ion spectra of ISO CO6 washed cotton fabric
with applied Matrix OSD Binder
8.2.3 P2i Process 3 Treatment
The Matrix OSD fabric was treated under the P2i Process 3 conditions and was
studied unwashed, washed and washed and heat pressed.
The positive ion ToF-SIMS spectra of unwashed fabric showed the presence of a
series of positive ion fluorocarbon species. As can be seen in Figure 8.42(a)-(c), the
corresponding species detected at the fibre surface are identified and tabulated in
Table 8.6. In the negative ion mode, a strong signal of F- ion is shown at 19
-, Figure
8.43(a), together with a series of negative ion fluorocarbon species assigned in Table
Chapter 8 Surface Analysis
223
8.7. The predominant longest perfluoro chain species formed during the P2i process
appears to be the C9F15- at m/z=393
-.
After washing, the fabrics have experienced a noticeable loss of oil repellency and
water repellency, as indicated in Chapter 6. While some evidence for surfactant
build-up from the detergents was evident through the LAS species on the textile
surface the loss of repellency maybe related to loss of fluorine from the surface or
molecular re-orientation and a reduction in surface fluorine species concentration,
Figures 8.44-8.45. The surface compositional changes associated with the F- species
at m/z = 19- have been calculated by referencing to the internal standard peak at m/z
= 25- (C2H
-). The 19
-/25
- ratio is 16.3 before washing while it is 5.5 after washing.
The effect of laundering was to deposit alkyl benzene sulphonates on the fibre
surface with the longer chain C13 species predominating due to its lower solubility
and higher affinity for the fibre rather than the higher concentration C11 and C12
derivatives in the original powder. C13 derivative is the most hydrophobic one of the
major components and therefore it has a stronger substantivity for the fabric surface.
Heat pressing causes the perfluoro-chains to orientate from the “sub-surface”
aqueous environment to the “exposed” repellent air condition. The intensities of
fluorocarbon species are higher than the washed ones, Figures 8.46-8.47, but the
ratio of F-/C2H
- is 15 which is almost the same as the unwashed samples. This is
reflected in the recovered oil/water repellency. There are still LAS on the surface of
heat pressed samples, although the intensities are much lower than with the washed
samples. Still, the longer chain C13 species predominates due to its lower solubility
and higher affinity for the fibre rather than the higher concentration C11 and C12
derivatives in the original powder.
Chapter 8 Surface Analysis
224
Table 8.6 Positive fluorocarbon species
Fluorocarbon species Atomic mass units
CF+ 31
+
CF2+ 50
+
CF3+ 69
+
C3F3+ 93
+
C2F4+ 100
+
C2F5+ 119
+
C3F5+ 131
+
C3F7+ 169
+
C4F7+ 181
+
C4F9+ 219
+
C5F9+ 231
+
C6F11+ 281
+
C7F13+ 331
+
C8F15+ 381
+
Table 8.7 Negative fluorocarbon species
Fluorocarbon species Atomic mass units
F- 19
-
F2- 38
-
CF3- 69
-
C2F5- 119
-
C3F5- 131
-
C3F7- 169
-
C5F7- 193
-
C6F9- 243
-
C7F9- 255
-
C7F11- 293
-
C9F13- 355
-
C9F15- 393
-
Chapter 8 Surface Analysis
225
(a)
(b)
(c)
Figure 8.42 (a)-(c) ToF-SIMS positive ion spectra of P2i Process 3 treated cotton
fabric with applied Matrix OSD
Chapter 8 Surface Analysis
226
(a)
(b)
(c)
Figure 8.43 (a)-(c) ToF-SIMS negative ion spectra of P2i Process 3 treated cotton
fabric with applied Matrix OSD
Chapter 8 Surface Analysis
227
(a)
(b)
(c)
(d)
(e)
Figure 8.44 (a)-(e) ToF-SIMS positive ion spectra of ISO CO6 washed P2i Process 3
treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
228
(a)
(b)
(c)
Figure 8.45 (a)-(c) ToF-SIMS negative ion spectra of ISO CO6 washed P2i Process 3
treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
229
(a)
(b)
(c)
Figure 8.46 (a)-(c) ToF-SIMS positive ion spectra of washed and heat pressed P2i
Process 3 treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
230
(a)
(b)
(c)
Figure 8.47 (a)-(c) ToF-SIMS negative ion spectra of washed and heat pressed P2i
Process 3 treated cotton fabric with applied Matrix OSD
8.2.4 FRN6 Treatment
The 135g/L Matrix OSD binder treated fabric was further treated with 60g/L FRN6
and subsequently washed and washed & heat pressed.
In general, the ToF-SIMS fluorocarbon ions observed in the FRN6 treated samples,
Figures 8.48-8.49, are similar to those observed in the P2i treated fabric ToF-SIMS
spectra, Tables 8.3 and 8.4. However, comparison with the ToF-SIMS spectra of the
P2i treated fabrics indicates the intensity of each fluorocarbon species in the FRN6
Chapter 8 Surface Analysis
231
fabric ToF-SIMS spectra are relatively lower. The 19-/25
- ratio is 11.2, while it is
16.3 for the P2i treated fabrics. The ToF-SIMS peak intensities at m/z = 281+ can be
assigned to C6F11+ suggesting that the perfluoro chains in the FRN6 finish are indeed
C6-based fluorocarbons. However examination of the negative ion spectrum
surprisingly shows a strong peak at m/z=293- which can be assigned to C7H11
-. The
nature of this anomaly is uncertain at present.
After washing, unlike the comparable P2i treated samples, there is little decrease in
the fluorocarbon related ion peak intensities, Figure 8.50-8.51. The 19-/25
- ratio is
11.6, which is almost the same as the unwashed samples. Further the water
repellency remains at the same level while the oil repellency fails, mentioned in
Chapter 6. The effect of laundering was to deposit alkyl benzene sulphonates on the
fibre surface as shown in the previous section, Figure 8.51(c). Like the washed
binder treated samples, the longer chain C13 species predominates due to its lower
solubility and higher affinity for the fibre rather than the higher concentration C11
and C12 derivatives in the original powder. C13 derivative is the most hydrophobic
surfactant of the major components and therefore it has a stronger substantivity for
the fabric surface. Interestingly, the intensity of LAS for those samples are treated
by P2i is higher than those treated by FRN6
Heat pressing of the washed fabrics caused a small decrease in ion intensities and
associated variable repellency performance, Figure 8.52-8.53. The ratio of F-/C2H
- is
10.5 which is almost the same as the unwashed and washed samples and is evidence
of the recovered oil repellency. There is still LAS on the surface of heat pressed
samples, although the intensities are slightly higher than washed samples.
Chapter 8 Surface Analysis
232
(a)
(b)
(c)
(d)
Figure 8.48 (a)-(d) ToF-SIMS positive spectra of 60g/L FRN6 treated cotton fabric
with applied Matrix OSD
Chapter 8 Surface Analysis
233
(a)
(b)
(c)
Figure 8.49 (a)-(c) ToF-SIMS negative spectra of 60g/L FRN6 treated cotton fabric
with applied Matrix OSD
Chapter 8 Surface Analysis
234
(a)
(b)
(c)
Figure 8.50 (a)-(c) ToF-SIMS positive ion spectra of ISO CO6 washed 60g/L FRN6
treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
235
(a)
(b)
(c)
Figure 8.51 (a)-(c) ToF-SIMS negative ion spectra of ISO CO6 washed 60g/L FRN6
treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
236
(a)
(b)
(c)
Figure 8.52 (a)-(c) ToF-SIMS positive ion spectra of washed & heat pressed 60g/L
FRN6 treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
237
(a)
(b)
(c)
Figure 8.53 (a)-(c) ToF-SIMS negative ion spectra of washed & heat pressed 60g/L
FRN6 treated cotton fabric with applied Matrix OSD
8.2.5 F-01 Treatment
The fabrics treated by 135g/L binder and 60g/L F-01 were tested at three different
conditions: unwashed, washed and washed & heat pressed.
The ToF-SIMS peak intensities at m/z = 231+, 281
+, 331
+, 381
+ can be assigned to
C5F9+, C6F11
+, C7F13
+ and C8F15
+ suggesting that the perfluoro chains are C5-, C6-,
C7- and C8-based fluorocarbons or the lower perfluoro analogues are ion fragments
generated by the analysis. In contrast the negative ion spectrum shows evidence of
Chapter 8 Surface Analysis
238
the C9F13- and C9F15
- species at m/z = 355
- and 393
-, respectively. The nature of this
anomaly is uncertain at present.
In general, the fluorocarbon species in the ToF-SIMS spectra of F-01 treated
samples, Figure 8.54-8.55, are similar to the P2i treated and FRN6 treated samples
which are shown in Tables 8.3 and 8.4. However, comparison of P2i treated and
FRN6 treated samples indicates that the intensity of each fluorocarbon species in
ToF-SIMS spectra of F-01 treated samples is relatively lower than P2i treated
samples and slightly higher than the FRN6 treated samples. However it is clearly
apparent that the F- in the negative ToF-SIMS spectra, Figure 8.55, dominates the
spectrum and the organic ions are less obvious.
After washing, there is some decrease of the perfluoro ion species, Figure 8.56-8.57,
and is the primary reason for the reduction in the observed water and oil repellency.
The effect of laundering was also to deposit alkyl benzene sulphonates on the fibre
surface as shown in previous section, Figure 8.57(c), and again the deposition and
relative substantivity is similar to the previous experiments: C13>C12>C11.
Interestingly, the intensity of LAS deposition is marginally greater in FRN6 treated
fabrics and maybe related to the lower repellency performance.
Again subsequent heat pressing increases the relative intensities of the perfluoro ion
species, but still lower than the unwashed samples, Figure 8.58-8.59. However it
again explains the observed recovery in oil repellency. The intensities of LAS left on
the fabric surface are slightly higher than the washed samples, which is the same as
the FRN6 treatment but opposite to the P2i treated fabrics.
Chapter 8 Surface Analysis
239
(a)
(b)
(c)
Figure 8.54 (a)-(c) ToF-SIMS positive spectra of 60g/L F-01 treated cotton fabric
with applied Matrix OSD
Chapter 8 Surface Analysis
240
(a)
(b)
(c)
Figure 8.55 (a)-(c) ToF-SIMS spectra of 60g/L F-01 treated cotton fabric with applied
Matrix OSD
Chapter 8 Surface Analysis
241
(a)
(b)
(c)
Figure 8.56 (a)-(c) ToF-SIMS positive ion spectra of ISO CO6 washed 60g/L F-01
treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
242
(a)
(b)
(c)
Figure 8.57 (a)-(c) ToF-SIMS negative ion spectra of ISO CO6 washed 60g/L F-01
treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
243
(a)
(b)
(c)
Figure 8.58 (a)-(c) ToF-SIMS positive ion spectra of washed & heat pressed 60g/L
F-01 treated cotton fabric with applied Matrix OSD
Chapter 8 Surface Analysis
244
(a)
(b)
(c)
Figure 8.59 (a)-(c) ToF-SIMS negative ion spectra of washed & heat pressed 60g/L
F-01 treated cotton fabric with applied Matrix OSD
8.3 Conclusions
XPS and ToF-SIMS have been used to successfully probe the outer surface of the
pigment dyed textile fabric treated with a range of wet and dry fluorocarbon finishes.
The fluorocarbon finishes have been characterised and their surface composition
related to the observed repellency and deposit surfactants on the fibre surface.
The XPS technique has provided an insight into the relative proportion of CF3 and
CF2 contribution to the surface fluoropolymers and the ToF-SIMS technique has
Chapter 8 Surface Analysis
245
provided information about the molecular structure of the finishes. In particular the
FRN6 finish appears to be “built” from C6 chain chemistry.
Some strong polyacrylate and PDMS signals were observed in the ToF-SIMS figures.
Therefore, the binder composition appears to be confirmed as an ethyl polyacrylate
and silicone softener.
8.4 References
1. Mitchell, R., Carr, C. M., Parfitt, M., Vickerman, J. C. and Jones, C., Surface
Chemical Analysis of Raw Cotton Fibres and Associated Materials, Cellulose,
2005, 12(6): p.629-639.
2. Shekarriz, S., An Investigation into the Modification of Cotton Fibres to
Improve Crease Resist and Repellancy Properties, UMIST PhD Thesis,
1999.
Chapter 9 Conclusions and Future Work
246
Chapter 9 Conclusions and Future Work
9.1 Summary and Conclusions
The Matrix OSD pigment dyeing system has been reported to offer benefits in terms
of processing cost and environmental impact. From the initial studies it was apparent
that while dry rub fastness, mechanical rigidity and washing performance were
generally acceptable the wet rub fastness of the printed fabrics presented a technical
challenge. On increasing the pigment incorporated into the surface binder film while
the colour strength increased the fastness properties decreased reflecting the
integrity of the film being compromised by the higher pigment concentrations. The
presence of silicone softener in the binder formulation offered some benefits in
terms of colour strength, handle and fastness but these effects are most likely due to
the surface film increasing specular reflectance and lubrication at the materials
interface.
SEM analyses of the pigment dyed fabrics offered further insight as to the colour
loss after rubbing with the Martindale Flat Abrasion tester. With the increase of
formulation concentration, more pigment was present on the fabric surface and
accordingly caused that more colour and associated polymer binder were lost during
rubbing. However the loss of the colourant did not affect the overall fabric
integrity/strength but rather were a visual effect.
Pigment dyeing offers the potential for colouration of any substrate however with
the Matrix OSD system it is apparent that comparison between 100% polyester
synthetic fabric and a polyester/cotton blend (55:45), the colour yield and durability
on the cellulosic fabrics was better. Therefore in the development of the project
cotton was the main focus as the main experimental substrate and improving the
Chapter 9 Conclusions and Future Work
247
fastness performance.
The studies aimed at modifying the pigment dyeing system with a view to
improving fastness, in particular improving the wet rub fastness, involved four
different approaches based on pre-cationization of the fabric (Chapter 5),
incorporation of crosslinkers into the binder formulation (Chapter 5), UVO pre-
treatment of the fabric (Chapter 5), and wet fluorocarbon treatment (Chapter 6) and
dry plasma polymerisation treatment (Chapter 7).
Cationizing the cotton fabrics prior to pigment dyeing improved the wet rub fastness
performance of the Matrix OSD dyeing system, but the other fastness properties
were in general unchanged. The cationization is most likely changing the surface
interface chemistry and improving adhesion and covalent bonding to the fibre
surface
Similarly crosslinking treatments enhanced the colour fastness performance, due to
the improvement of the bonding between the binder and fabrics. The crosslinking
pre-treatment offers better performance than the combined application method in
terms of improving the wet rub fastness. Moreover, the crosslinker has almost no
effect on wash fastness which always remains at an acceptable performance level
with most crosslinkers. Of the system assessed the Knittex MLF New pre-treatment
offers the best option to improve the colour fastness, with the optimum application
level being 40g/L.
Unlike the benefits of UVO pre-treatment previously observed for other long liquor
fabric dyeing studies, in this study it was established that the pigment dyeing
performance was reduced after the sensitised photo-oxidation treatment. The reason
for this decrease in performance is unclear but it is perhaps due to the oxidised fibre
surface interface not providing appropriate reactive functionalities or the mechanical
Chapter 9 Conclusions and Future Work
248
strength of the interface polymer weakening the integrity of the cellulose/pigment
binder layer.
The effect of applying fluorocarbons to the pigment dyed fabrics had a beneficial
effect on wash fastness and wet rub fastness, while dry rub fastness was marginally
reduced at higher fluorocarbon application levels. Comparison of the fastness
performance of the different fluorocarbon treated cotton indicated the best
application condition was found when the dyed samples were aftertreated with
20g/L Shield F-01 with 8g/L Shield extender FCD. At this F-01 concentration, rub
fastness and wash fastness were all at an excellent level, above 4. Similarly with the
polycotton fabric the benefits of the F-01 treatment were apparent, particularly at the
20g/L application level. Although the dry P2i plasma treatment cannot achieve a
similar level of fastness as the aqueous fluorocarbon treatments, it still imparted
improved water/oil repellency and fabric handle.
SEM analysis of the fabrics damage due to the wet and dry rubbing indicates wet
abrasion is more damaging but that there was less damage in the samples treated
with the F-01 fluorocarbon.
The surface sensitive XPS and ToF-SIMS techniques have been used to successfully
probe the outer surface of the pigment dyed textile fabric treated with a range of wet
and dry fluorocarbon finishes. The fluorocarbon finishes have been characterised
and their surface composition related to the observed repellency and deposit
surfactants on the fibre surface. The XPS technique has provided a valuable insight
into the relative proportion of the CF3 and CF2 polymer components in the surface
fluoropolymers and the ToF-SIMS technique has provided information about the
molecular structure of the finishes. In particular the FRN6 finish is clearly identified
as “built” from C6 chain chemistry.
Chapter 9 Conclusions and Future Work
249
When fluorocarbon application treatment was combined with the pigment dyeing
systems, there was a deleterious effect on abrasion resistance and a reduced
performance was observed. However, when the fluorocarbon is directly applied onto
undyed cotton fabrics, the abrasion resistance was improved, the Oleophobol
treatment giving the best result at the concentration of 60g/L. The combination of
the two systems appears to have a deleterious effect and the nature of this
antagonistic interaction is uncertain at present.
Water and oil repellency imparted by the fluorocarbon was the same on uncoloured
cotton as that observed on coloured cotton. There were almost no repellency results
related to softener in binder, except for the exhaustion application method with
7%owf Oleophobol 7713 and 8%owf Rucoguard LAD which the water and oil
repellency results are obviously higher than the padding application method. This is
probably because the longer treating time during the exhaustion application makes
more chemicals staying on the fabric surface.
A range of plasma pre- treatments prior to pigment dyeing were examined but only a
marginal benefit on fastness properties and to some extent slightly decreased dry rub
fastness were observed. However, colour strength was improved under all gas
conditions. Mixed gases treatments (He & O2 and He & N2) were better than the
single gas treatment (He), although again the nature of the specific chemical
modifications is unclear. Plasma aftertreatments, using both Ar and N2 atmospheres,
improved the fastness, particularly wet fastness, when the binder heat curing process
was before plasma treatment probably due to crosslinking the outer polymer surface.
Overall, the treatment which showed the most beneficial improvement in this study
was the 20g/L Shield F-01 after-treatment where all fastness properties are at an
excellent level, above 4. In addition the colour strength was unaffected.
Chapter 9 Conclusions and Future Work
250
9.2 Future Work
- In recognising the benefits of surface fluorocarbon finishes and the influence of the
surface interface on pigment binder fastness performance further studies should
focus on the ToF-SIMS chemical analysis technique in that it provides molecular
and functional group information. This insight may be beneficial in identifying and
engineering better surface adhesion and bonding at the treated cotton surface, hence
leading to better fastness performance.
- The surface interface will also affect the mechanical properties of the treated cotton
fabric, in particular fabric handle. The effect of washing on the handle should be
examined further and therefore the relationship between surface binder and
fluorocarbon composition and the associated handle properties determined.
- The repellency performance after fluorocarbon treatments should be investigated
particularly due to the relatively low repellency results in this study. In the same
time the repellency behaviour on different textile materials, such as wool, polyester
and polyester/cotton should be examined further.
- The optimisation of the pigment dyeing system on other single fibre or blend
fabrics, such as wool, silk, polyester and polyester/cotton should be investigated in
order to broaden the application and commercial scope and improve fastness
performance.
- The beneficial applications in pigment dyeing system should be studied in related
pigment printing system to overcome the fastness and handle problems.