Effect of protease treatment on dyeing properties of wool fabrics for single bath

Abstract

During the conventional process of dyeing for wool fabric, the most important problem is the damage to wool fiber and energy waste because of high temperature. In this paper, the effect of a commercial protease, Savinase 16L from Novozymes, on low temperature dyeing properties of wool fabric was studied. The results showed that after treatment with protease for 30 min at 50°C and pH 8.0, the exhaustion of the Acid Yellow 116 on wool fabric increased 11.11% and 8.58% by comparing with that on the control samples without protease treatment when dyeing at 80°C and 90°C, respectively. And the dye absorption at 90°C on protease pretreated wool fabric was almost the same as that with the conventional boiling dyeing procedure. A single bath process containing protease treatment at 50°C and pH 8 and dyeing at 90°C and pH 4 was investigated. The dyeing effect of wool fabric dyed with one-bath process was nearly the same as that with the two-bath method and conventional boiling dyeing process. The results suggest that protease treatment offers an option of a one-bath dyeing process, replacing the water- and energy-consuming two-bath method and conventional dyeing process.