Application Of Composite Enzymes In Liquid Laundry Detergent

Enzymes are a kind of biologic catalyzers with the property of specificity,efficiency andtenderness,which have been widely used in laundry detergents.Enzymes can evidentlyimprove the performance of laundry detergent.The influence on detergency of the composition of protease and amylase in liquid laundrydetergent has been investigated in this disquisition. The influence of anionic and nonionicsurfactants on the stability of protease and amylse was also investigated. The enzymestabilizer was investigated by Orthogonal experiment. The mechanism of different factorsthat influence on the stability of enzymes was simply disscussed in the disquisition. Theinfluence of the composition of5-chloro-2-methyl-4-isothiazolin-3-ketone （CMIT） and2-methyl-4-isothiazo1in-3-ketone （MIT） on performance of antisepsis was also investigated.The test results show that, with the application of protease and amylase in liquiddetergent, the detergency on protein and starch soil improved obviously, and there was alsosynergic effect between protease and amylse which could improve the total detergency ofliquid laundry detergent. It was found that linear alkylbenzene sulfonate （LAS） stronglyaffected the stability of protease and amylse, alkyl polyoxyethlene ether sulfate （AES） andcoconut fatty acid have slight influence on the stability of enzyme, but may also make theenzyme inactive under long-time storage. Nonionic surfactants such as alkyl polyoxyethyleneether （AEO₉） have almost no influence on the stability of enzyme. When composition withnonionic surfactants, the influence of anionic surfactants on enzyme stability can be reducedevidently.Test results also showed that calcium ion was the key factor which can makeprotease and amylse stable in the solution. Secondly, with the dosage of3.5%of4-FPBAcould restrain the activity of protease, and prevent the protease from decompounding amylse.By Orthogonal experiment, we optimized a stabilizer formla containing CaCl₂, propyleneglycol, borax,4-FPBA and TEA. CMIT and MIT are widely used preservatives in liquiddetergents, but test results showed that MIT decreased more faster in enzymecontaining（especially protease） detergent than in enzyme-free detergent. With the presence ofBIT, the speed of MIT decompounding decreased evidently.