Advantages of a two-step enzymatic process for cotton-polyester blends

Cotton fabric samples were treated with a formulation of a total crude Trichoderma reesei cellulase in a two-step procedure. In the first step, samples were treated at a low liquor ratio by padding through the enzyme formulation at 21 degrees C and 55 degrees C with a wet pickup of 100% and batched for 12 h. The samples were then treated at a high liquor ratio (1:25) with an identical enzyme formulation at 55 degrees C, with intensive agitation. The pre-treatment influenced the overall weight loss and rate of hydrolysis in samples, and the protein concentration in the liquor of the second step. The overall weight loss was 25-28% (w/w) in the two-step procedure compared to a weight loss of 22% (w/w) in the one-step batch hydrolysis.