Saminathan Ratnapandian

Contents

Title page

Declaration ii
Acknowledgements iii
List of figures ix
List of tables xii
Abstract xiii
Research output from this thesis work xvii

1. 
   Chapter 1 1
   
   1. 
      Introduction 2
      
   2. 
      Textile colouration 3
      
      1. 
         Dyes 3
         
         1. 
            Synthetic dyes 3
            
         2. 
            Natural dyes 6
            
      2. 
         Fabric colouration 12
         
         1. 
            Batch dyeing 12
            
         2. 
            Continuous dyeing 15
            
         3. 
            Printing 17
            
         4. 
            Unconventional dyeing 18
            
         5. 
            Improving textile colouration 18
            
      3. 
         Fastness testing 19
         
   3. 
      Present scenario 19
      
      1. 
         Research on natural dyes 21
         
         1. 
            Sources and extraction 22
            
         2. 
            Application techniques 22
            
         3. 
            Performance of natural dyes 23
            
         4. 
            Objections to natural dyes 23
            
   4. 
      Research conducted in this thesis 24
      
      1. 
         Chapter outline 25
         
      2. 
         Expected outcomes and potential benefits 25
         

2. 
   Chapter 2 26
   
   1. 
      Introduction 27
      
   2. 
      Design of experiments 27
      
      1. 
         Selection of materials 28
         
         1. 
            Fabrics 28
            
         2. 
            Dyes 29
            
         3. 
            Chemicals 32
            
      2. 
         Dyeing methods 33
         
         1. 
            Mordant dyes 33
            
         2. 
            Vat dyes 34
            
      3. 
         Evaluation 36
         
         1. 
            Colour measurement 36
            
         2. 
            Fastness testing 37
            
         3. 
            Atomic Absorption Spectrometry (AAS) 37
            
         4. 
            Attenuated Total Reflectance Fourier Transform Infra-Red (ATR- FTIR) 39
            
         5. 
            Wettability testing 39
            
         6. 
            Antimicrobial testing 40
            
   3. 
      Summary 41
      

3. 
   Chapter 3 42
   
   1. 
      Introduction 43
      
   2. 
      Equipment 43
      
      1. 
         Padding mangle 43
         
      2. 
         Steamer 43
         
      3. 
         Dryer 44
         
      4. 
         Attenuated Total Reflectance Fourier Transform Infra-Red (ATR-FTIR) 44
         
      5. 
         Atomic Absorption Spectrometer (AAS) 45
         
   3. 
      Materials 45
      
   4. 
      Methods 46
      
      1. 
         Exhaust dyeing 46
         
      2. 
         Padding 46
         
         1. 
            Optimising process sequence 47
            
         2. 
            Optimising dye-mordant ratio 48
            
      3. 
         Steaming and washing off 48
         
      4. 
         Dyeing evaluation 49
         
      5. 
         Atomic Absorption Spectrometry (AAS) 49
         
      6. 
         ATR–FTIR analysis 50
         
   5. 
      Results and discussion 50
      
      1. 
         Shades obtained 50
         
      2. 
         ATR–FTIR results 53
         
      3. 
         Optimal processing sequence 57
         
      4. 
         Optimum mordant concentration 59
         
         1. 
            AAS results 61
            
      5. 
         Fastness properties 63
         
   6. 
      Conclusions 64
      

4. 
   Chapter 4 66
   
   1. 
      Introduction 67
      
   2. 
      Plasma technology 67
      
   3. 
      Equipment 69
      
      1. 
         Plasma machine 69
         
      2. 
         Padding mangle, steamer and dryer 70
         
   4. 
      Materials 70
      
   5. 
      Methods 71
      
      1. 
         Plasma pretreatment 71
         
      2. 
         Padding 72
         
      3. 
         Evaluation 72
         
   6. 
      Results and discussion 72
      
      1. 
         Fabric wettability 72
         
      2. 
         Effect of plasma treatment on shade obtained 73
         
      3. 
         Fastness properties 78
         
   7. 
      Conclusions 78
      
5. 
   Chapter 5 80
   
   1. 
      Introduction 81
      
      1. 
         Application of chitosan in dyeing 81
         
      2. 
         Antimicrobial activity of chitosan 82
         
   2. 
      Equipment 82
      
      1. 
         Padding mangle, curing chamber and dryer 82
         
      2. 
         Antimicrobial testing 83
         
   3. 
      Materials 83
      
   4. 
      Methods 83
      
      1. 
         Padding 83
         
      2. 
         Evaluation 84
         
   5. 
      Results and discussion 84
      
      1. 
         Shades obtained 84
         
      2. 
         Effect of chitosan 85
         
      3. 
         Fastness properties 89
         
      4. 
         Antibacterial evaluation results 89
         
   6. 
      Conclusions 91
      

6. 
   Chapter 6 93
   
   1. 
      Introduction 94
      
      1. 
         Thiourea dioxide (TUD) 94
         
      2. 
         Sodium carbonate 94
         
   2. 
      Equipment 95
      
      1. 
         Padding mangle, steamer and dryer 95
         
      2. 
         Printing 95
         
   3. 
      Materials 95
      
   4. 
      Methods 96
      
      1. 
         Indigo dyeing 96
         
      2. 
         Printing with indigo 99
         
      3. 
         Evaluation 101
         
   5. 
      Results and discussion 102
      
      1. 
         Dyeing 102
         
         1. 
            Shades obtained 102
            
         2. 
            Effect of steaming time and alkali 104
            
         3. 
            Fastness properties 107
            
      2. 
         Printing 108
         
         1. 
            Shades obtained 108
            
         2. 
            Effect of alkali and steaming duration 110
            
         3. 
            Evaluation of fastness 111
            
   6. 
      Conclusions 112
      

7. 
   Chapter 7 114
   
   1. 
      Introduction 115
      
      1. 
         Padding of mordant dyes 115
         
      2. 
         Improving padding of mordant dyes 116
         
      3. 
         Indigo colouration 116
         
   2. 
      Further work 118
      
      1. 
         Increasing the scale of experiments 118
         
      2. 
         Analysis of dye-metal-textile complex 118
         
      3. 
         Effects of chitosan 118
         
      4. 
         Indigo colouration 118
         
8. 
   References 120
   

List of figures

Figure 1.1 Classification of synthetic dyes 4

Figure 1.2 Typical chemical groups of natural dyes 9
Figure 1.3 Fabric colouration methods 12
Figure 1.4 Exhaust dyeing line diagram 13
Figure 1.5 Schematic diagram of padding 16
Figure 1.6 Distribution of global dye demand 21
Figure 2.1 Design outline for padding natural dyes 28
Figure 2.2 Indigo formation in plants 30
Figure 2.3 Four possible stereo-isomeric dimers of profisetinidine 31
Figure 2.4 Polymers of condensed tannins 32
Figure 2.5 Solubilising reaction of indigo 34
Figure 2.6 Various types of indigo printing 35
Figure 2.7 Schematic diagram of AAS 38
Figure 2.8 Schematic diagram of ATR – FTIR 39
Figure 3.1 Padding mangle geometry 43
Figure 3.2 Laboratory scale steamer 44
Figure 3.3 Perkin Elmer Spectrum 400 FTIR 45
Figure 3.4 Varian AA 280 FS (AAS) 45
Figure 3.5 Mordanting and dyeing combinations 48
Figure 3.6 Reflectance curves of cotton fabrics dyed with A. catechu 51
Figure 3.7 Reflectance curves of cotton fabrics dyed with A. nilotica 51
Figure 3.8 Schematic of metal complex formation 52
Figure 3.9 Equatorially coordinated copper with cellulose 52
Figure 3.10 FTIR spectra of dyes 54
Figure 3.11 FTIR spectra of complexes formed by the two dyes in combination with copper 55
Figure 3.12 FTIR spectra of complexes formed by the two dyes in combination with iron 55
Figure 3.13 FTIR spectra of cotton fabric dyed in combination with copper as mordant
. 56
Figure 3.14 FTIR spectra of cotton fabric dyed in combination with iron as mordant..57 Figure 3.15 Comparison of colour strength (A. catechu) padded on cotton 60
Figure 3.16 Comparison of colour strength (A. nilotica) padded on cotton 61
Figure 3.17 Calibration curve for AAS 61
Figure 4.1 Schematic representation of plasma 67
Figure 4.2 APC 2000 atmospheric plasma treatment system 70
Figure 4.3 APC 2000 side view showing position of electrodes 70
Figure 4.4 Schematic sample set-up for plasma treatment 71
Figure 4.5 Effect of plasma gas on depth of shade 74
Figure 4.6 Effect of plasma gas on depth of shade 74
Figure 4.7 Effect of plasma gas on depth of shade 75
Figure 4.8 Effect of plasma gas on depth of shade 75
Figure 4.9 Effect of varying the plasma parameters on padding Caspian dye on wool fabric 76
Figure 4.10 Effect of varying the plasma parameters on padding Thar dye on wool fabric 76
Figure 4.11 One-step patterning 78
Figure 5.1 Schematic structure of chitosan 81
Figure 5.2 Line diagram of pad dyeing in the presence of chitosan 84
Figure 5.3 Reflectance curve for Caspian 85
Figure 5.4 Reflectance curve for Thar 85
Figure 5.5 Shade card for Thar dye 86
Figure 5.6 Shade card for Caspian dye 87
Figure 5.7 Comparison of sum of the K/S values for Caspian dye 87
Figure 5.8 Comparison of sum of the K/S values for Thar dye 88
Figure 5.9 Bacterial growth on agar plates for Thar (A) and Caspian (B) dyes 90
Figure 5.10 Agar plates control (A) and fabric dyed with Thar and 0.05% chitosan (B)
. 91
Figure 6.1 K-Bar hand coater 95
Figure 6.2 Modified vat pad-dyeing process 97
Figure 6.3 Schematic process sequence diagram 101
Figure 6.4 Comparison between exhaust dyeing and padding – natural indigo 102
Figure 6.5 Comparison between exhaust dyeing and padding – synthetic indigo 103
Figure 6.6 Reflectance curves – synthetic and natural indigo, 103
Figure 6.7 Effect of steaming duration on colour strength (reduced in Bath A) 105
Figure 6.8 Effect of steaming duration on colour strength (reduced in Bath B) 105
Figure 6.9 Reflectance curves natural indigo (Bath A 90 s and Bath B 6 min) 107
Figure 6.10 Printed indigo reduced using Bath A (TUD + caustic soda) 109
Figure 6.11 Reflectance curves comparing print shades from synthetic and natural indigo reduced using Bath A 109
Figure 6.12 Effect of alkali on indigo printing 110