Study of atmospheric plasma treatment on the pigment application to cotton fabric

xviii, 203 pages : illustrations (some color) ; 30 cmPolyU Library Call No.: [THS] LG51 .H577M ITC 2014 ManThe thesis was written for the study of atmospheric pressure plasma on pigment application to cotton fabric. The popularity of pigment usage is gradually increasing, since no subsequent steaming and washing off bring extra benefits to environment. Aiming at improving color yield, levelness and colorfastness of pigmented cotton fabric, atmospheric pressure plasma treatment was carried out before pigment coloration. Non-polymerizing helium-oxygen plasma treatment showed significant improvement on fabric hydrophilicity by physical and chemical alternation. Etching by atomic helium and oxygen increased the fibre surface roughness; wicking process was facilitated by spontaneous replacement of solid-air interface to solid-liquid interface. Oxidation of cotton fibre surface caused by reactive oxygen species greatly enhanced the adhesion force between the polymer surface and the water molecules by introducing new oxygen containing functional groups like OH and -C-O. High level of discharge power and oxygen flow rate, slow jet moving speed and medium jet to substrate distance contributed a better water absorbency improvement to cotton fabric. Moreover, the change in water absorption was mainly related to the morphological change rather than increment of oxygen content when changing parameters settings. SPSS analysis software was used to investigate the influence of plasma parameters to wickability and wettability by linear regression model. And linear regression equations for wicking coefficient and drop area prediction were obtained. In this study, color yield of blue, red and yellow pigment applications were slightly improved by atmospheric pressure helium-oxygen plasma treatment. A dramatic improvement on blue, red and yellow crocking fastness of cotton fabric is shown after helium-oxygen plasma treatment. The improvement was mainly attributed by cotton fibre surface roughness increment and oxygen containing group insertion. SPSS analysis software was used to investigate the influence of plasma parameters on color yield and crocking fastness by linear regression model. However, only crocking fastness variation can be well explained by the linear regression model. High level of discharge power, high oxygen flow rate or slow jet moving speed of plasma treatment gave an excellent modification on crocking fastness to cotton fabric. However, the levelness of pigmented fabric was worse after treatment due to high roughness surface. Finally, the dry cleaning fastness of pigmented samples by Printofix T&A Pigment and Printofix Binder MTB-01/N-85/CFN was good due to extremely small pigment size.Institute of Textiles and ClothingM.Phil., Institute of Textiles and Clothing, The Hong Kong Polytechnic University, 201