One Step Low-temperature Enzymatic Treatment For Denim Garments

Three low temperature enzymatic treatment methods were used to combine the dezizing and stone washing into one step, to study the changes in the performance of denim fabric. The first method is of dry pretreatment plus low temperature enzyme washing processing, the ozone and plasma methods were used as the pretreatment for both indigo denim and sulphur black denim fabric. The fabric color, tensile strength, softness and size removal rate were measured and analyzed. It can be concluded that the first cellulase treatment followed by ozone finishing is better than only ozone treatment and the first ozone treatment followed by cellulase treatment; Optimum Plasma treatment condition for sulphur black denim fabric is of 80-80 pa, 3 min, 119 w, for indigo denim fabric treatment is 35-40 pa, air pressure for 1 min, 119 w.The second method is to use composite enzyme at low temperature, the treatments were carried out according to central composite experiment design at 25℃ for indigo denim, amylase, cellulase, laccase and pH value were used as impact factor. The fabric color, tensile strength, capillary effect, size removal rate were measured, analysed and optimised using minitab 15 software. The results showed that significant interaction effect on fabric properties among cellulase, laccase, amylase, pH value. Amylase, laccase, pH and cellulase and laccase interaction affect the L value significantly. Laccase and laccase and cellulase interaction effect on K/S value of the most significant, cellulase and amylase give significant action on capillary effects of fabric, cellulase showed the strongest action on tensile strength. Under optimized conditions, the fabric properties achieved by low-temperature one-step processing are closed to the traditional two-step process.The third method is of chemical plus low temperature cellulase treatment process. The indigo fabrics were firstly treated according to design with the orthogonal experiment method, with sodium hypochlorite, sodium hydroxide, ammonium chloride, and time as the impact factors at25 ℃, and followed by cellulase treatment for 25 and 50 min. The color of the fabric, weight reduction rate and flexible index were analyzed and optimized. It can be concluded that the optimum concentration of sodium hypochlorite is of 25 g/L, treatment 5 min, optimum cellulase concentration is of 1.82 g/L, treatment 50 min, after treatment, fabrics showed enhanced brightess, fiding color, good size removal, tensile strength and softness.