Influence of chitosan posttreatment parameters on the fixation of pigment-based inks on ink-jet-printed cotton fabrics

Abstract

Cotton fabrics were digitally printed with pigment-based black ink with an HP Desk-Jet 880C printer. These ink-jet-printed fabrics were posttreated with chitosan samples for the fixation of the pigment-based ink on the cotton. The influence of various parameters, including the molecular weight (MW), application method (pad–dry–cure vs pad–batch), concentration, and pH, on the degree of fixation (DF) of the pigment-based inks was examined. The chitosan-posttreated cotton samples were evaluated for their color strength, DF, color difference, and whiteness index values and their colorfastness properties. Chitosan samples with MWs of 150,000 and greater than 375,000 showed 100% (complete) fixation of the pigment-based inks on the cotton fabrics. DF drastically decreased in the chitosan with an MW of less than 5000. Both the pad–dry–cure and pad–batch methods were found to be suitable for chitosan application onto ink-jet-printed fabrics. Chitosan with an MW of 150,000 showed 100% fixation at concentrations ranging from 0.3 to 1%. A further decrease in the concentration significantly decreased the fixation. High fixation values were achieved at acidic pH, whereas a neutral to alkaline pH resulted in poor fixation. The colorfastness properties for each parameter studied are also discussed. The posttreatment of the digitally printed cotton with chitosan was found to be very effective in fixing the pigment-based inks. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010