Protease, a new tool for denim washing

Cellulase enzymes have been widely used in denim processing to produce fashionably aged looks. Conventional whole acid stable cellulases are being used successfully to achieve a worn look with short process times. The final look achieved by these types of enzymes is usually characterized as flat and low contrast, due to a high level of backstaining. Literature reports suggest that backstaining is caused by many of the proteins present in the conventional whole acid stable cellulases. In this study, laboratory scale wash performance tests were conducted using a unique protease under different processing conditions. The protease added during rinsing or at the end of the cellulase washing step resulted in significant reduction of backstaining and improved contrast. The protease treatment at low temperatures also removed all but trace amounts of residual cellulase bound to the denim.