Evaluation of enzymatic hydrolyzed starches in discharge, discharge-resist and burn-out printing styles

Abstract

Maize starch samples have been subjected to gelatinization at 70 degrees C followed by enzymatic treatment using different concentrations of a-amylase enzyme (0.025, 0.050, 0.075 and 0.1 mL/50g starch) and then used in printing paste as thickener for discharge, discharge-resist and burn-out printing on cotton, wool/polyester and viscose/polyester/lucre fabrics. The results show that enzymatic treatment of maize starch converts the rheological properties of starch from thixotropic into pseudo-plastic. Increase in a-amylase enzyme concentration is accompanied, by a decrease in the apparent viscosity. While enzyme-treated starches give better results when used as thickening agent in discharge-resist printing compared with sodium alginate, the opposite holds true in case of discharge printing. Enzyme-treated starches specially that prepared using 0.1 mL/50g starch could act successfully as thickening agent in burn-out printing of both wool/polyester and viscose/polyester/lucre blends.