Biological Enzyme Catalysis The Bleaching Process Of Cotton Knitted Fabric At Low Temperature

Resource management and environmental protection is a major challenge for the textile industry.Cotton fabric is a main processing object in the textile printing and dyeing industry.Its scouring and bleaching process often use high temperature and strong alkali in the treatment process.Although the fabric properties have been greatly improved,the process consumes a lot of energy and brings a large amount of alkaline wastewater which resulted in the waste of resources,but also damaged the ecological environment.Low temperature biological enzyme catalysis bleaching refers to the enzyme catalytic carboxylate acid ester and hydrogen peroxide reaction to peroxyacetic acid,and the fabric was bleached at low temperature and low pH value.The combination of the enzymatic bleaching and scouring of knitted can achieve cleaner production pretreatment.The application performance of the esterase were discussed,the optimal dosage or conditions were determined by single factor test and orthogonal test:scouring agent 2g/L,stabilizer 3g/L,hydrogen peroxide 12g/L,esterase 3g/L,three acetic acid glycerol ester 8g/L,pH value is 9.5,temperature is 70℃,time is 60min,bath ratio 14:1.The evaluation of the effect of biological enzyme scouring and bleaching fabrics is through the treated fabric whiteness,the bursting strength loss and the fabric wetting time.The results show that the treated fabric whiteness reaches 73%,bursting strength loss was 10%,the fabric wetting time is less than 2s,the surface of the fabric without cottonseed shell,soft to the touch.The content of peroxide was titration,and the bleaching mechanism is discussed.The results showed that,carboxylic ester and hydrogen peroxide with lipase can generate peroxy acetic acid anions which bleaching fabric weak alkaline conditions.Results showed that,adding ester and esterase in the pretreatment solution can reduce the bleaching temperature,pH of bleaching solution and make the fabric whiteness better.It can not only avoid-the acid pickling and reduces the times of water washing but also minimize the impact on the environment.