Enzyme washing of indigo and sulphur dyed denim

A wide ranging finish effects have been given to denim fabrics in industrial scale to make it more fashionable and functional. Among the numerous wet and dry treatments given, worn out looks of various kinds have received the maximum attention. In this context, herein, two denim fabrics, one dyed with vat indigo and the other with sulphur black were enzyme washed. The enzymes used were acid cellulase and neutral cellulase and the treatments were done at varying concentrations, time and mechanical agitation. The trials so taken were based on design of experiments, and the effect was analysed in terms of decrease in colour depth and weight loss. Back staining of fabric during the wash was also checked and acid enzyme despite higher colour removal, caused significant staining in sulphur dyed quality. Attempt was made to contain this back staining by suitable treatment. The application conditions of cellulases on the denim qualities were also optimized for fading effect.