Investigation of Fibre Protection and Water Saving in the Wet Processing of Textiles A thesis submitted to the University of Manchester for the degree of Doctor of Philosophy (PhD) in the Faculty of Engineering and Physical Sciences 2014 Bo Ning School of Materials List of Contents List of Contents ............................................................................................................ 2 List of Tables ................................................................................................................. 7 List of Figures ............................................................................................................. 14 List of Equations ........................................................................................................ 16 Abstract ....................................................................................................................... 17 Declaration.................................................................................................................. 18 Copyright Statement .................................................................................................. 19 Acknowledgements .................................................................................................... 20 Chapter 1 Introduction .............................................................................................. 21 1.1 Wool and cotton ........................................................................................................... 21 1.1.1 Wool .................................................................................................................... 21 1.1.2 Cotton .................................................................................................................. 33 1.2 Fibre damage during wet processing of wool and cotton .................................... 36 1.2.1 Fibre damage during bleaching ...................................................................... 36 1.2.2 Fibre damage during dyeing ........................................................................... 40 1.2.3 Fibre protection ................................................................................................. 44 1.3 Water saving in the textile industry .......................................................................... 45 1.3.1 Water consumption in the textile industry ................................................... 45 1.3.2 Textile effluent characteristics ....................................................................... 46 1.3.3 Application of filtration in effluent treatment ............................................. 48 1.3.4 Potential of sea water used in the wet processing of textile..................... 55 1.4 Feather- A potential fibrous resource ...................................................................... 58 1.4.1 Structure .............................................................................................................. 58 1.4.2 Chemical composition ..................................................................................... 59 1.4.3 Physical properties of feather fibre ............................................................... 60 1.4.4 Feathers as potential filter media ................................................................... 60 1.5 Aims and objectives of the thesis ............................................................................. 61 2 1.5.1 Minimize the damage of fibres in the wet processing of textiles ........... 61 1.5.2 Reduce fresh water usage during the wet processing of textile .............. 62 Chapter 2 Introduction to analytical techniques .................................................... 70 2.1 Colour measurement .................................................................................................... 70 2.1.1 Colour Strength ................................................................................................. 70 2.1.2 CIE L*a*b* ........................................................................................................ 70 2.1.3 CIE Whiteness Index ....................................................................................... 71 2.1.4 ASTM E313 Yellowness index ..................................................................... 72 2.2 Absorption Spectrometry ............................................................................................ 72 2.3 Scanning Electron Microscopy (SEM) .................................................................... 73 2.3.1 SEM principle .................................................................................................... 73 2.3.2 SEM instrumentation ....................................................................................... 75 Chapter 3 Experimental ............................................................................................ 78 3.1 Bleaching of wool and cotton .................................................................................... 78 3.1.1 Materials ............................................................................................................. 78 3.1.2 Hydrogen peroxide bleaching procedures for wool and cotton .............. 79 3.1.3 Reductive bleaching procedures for wool ................................................... 79 3.1.4 Application of fibre protective agents .......................................................... 80 3.2 Blank dyeing of wool .................................................................................................. 80 3.2.1 Materials ............................................................................................................. 81 3.2.2 Dyeing procedures ............................................................................................ 81 3.2.3 Application of fibre protective agents .......................................................... 81 3.3 Wet processing of wool and cotton in simulated seawater .................................. 82 3.4 Dye removal from effluent ......................................................................................... 82 3.4.1 Dye adsorption of modified paper filters ..................................................... 82 3.4.2 Dye adsorption of modified PVP nanofibres .............................................. 85 3.5 Measurements of physical and mechanical properties ......................................... 86 3.5.1 Whiteness and yellowness measurements ................................................... 86 3.5.2 Colour strength .................................................................................................. 86 3.5.3 Absorbance measurements ............................................................................. 86 3 3.5.4 Tensile strength measurements ...................................................................... 87 3.5.5 Martindale Abrasion Resistance .................................................................... 88 3.5.6 Kawabata Evaluation System (KES) ............................................................ 88 3.5.7 Scanning Electron Microscopy (SEM) ........................................................ 90 Chapter 4 Effect of hydrogen peroxide bleaching on wool and cotton ................. 93 4.1 Hydrogen peroxide bleaching of wool .................................................................... 93 4.1.1 Alkaline hydrogen peroxide bleaching of wool ......................................... 93 4.1.2 Acid hydrogen peroxide bleaching of wool ................................................ 95 4.2 Hydrogen peroxide bleaching on cotton ................................................................. 97 4.2.1 Hydrogen peroxide bleaching on scoured and bleached cotton .............. 97 4.2.2 Hydrogen peroxide bleaching on scoured unbleached cotton ................. 99 4.2.3 Higher temperature bleaching on scoured unbleached cotton ............... 101 4.3 Conclusions ................................................................................................................. 103 Chapter 5 Effect of fibre protective agents on wool and cotton bleaching ......... 106 5.1 Effect of Keravis™ on bleaching of wool ............................................................ 106 5.1.1 Effect of Keravis™ on the whiteness of bleached wool fabric ............. 106 5.1.2 Effect of Keravis™ on the abrasion resistance of bleached wool fabric ....................................................................................................................................... 107 5.2 Effect of tannic acid on bleaching of wool fabric ............................................... 107 5.3 Effect of Byco C on bleaching of wool fabric ..................................................... 109 5.3.1 Effect of Byco C on oxidative bleaching of wool fabric ........................ 109 5.3.2 Effect of Byco C on oxidative and reductive bleaching of wool fabric ....................................................................................................................................... 112 5.3.3 Effect of VoluminisTM on bleached wool fabric ...................................... 115 5.4 Effect of Byco C in the bleach bath on bleaching of cotton fabric .................. 120 5.4.1 Effect of Byco C in the bleach bath on bleaching of scoured and bleached cotton fabric .............................................................................................. 120 5.4.2 Effect of Byco C on bleaching of scoured