Chitosan as a Thickener for Direct Printing of Natural Dye on Cotton Fabric

Development of chitosan as a thickener for direct printing of natural dye on cotton fabric was investigated. Chitosan was applied as a thickener at various concentrations and its effect on the print properties was determined in comparison with the typical printing thickener, sodium alginate. The results exhibited that chitosan affected the fabric properties by increasing fabric yellowness and stiffness. However, with increasing chitosan concentrations, the yellowness reduced only marginally. Direct printing on cotton fabric with 3% Natural Chestnut at varying chitosan concentrations showed that the optimum chitosan concentration for the printing was at 3%w/v, being equivalent to the viscosity of 17,800 mPa. The 3%w/v chitosan imparted the ultimate color yield, print outline sharpness and a minimal dye bleeding on the unprinted area of the fabric. Use of chitosan concentration higher than 3%w/v led to poor print properties on the fabric. The efficiency as a thickener of chitosan was found to be superior to sodium alginate. A high color yield and good color fastness properties on cotton fabric were rendered in the case of chitosan thickener at the same applied concentration with sodium alginate.