Enzymatic Unhairing Technology Assisted With Auxiliary

The leather industry world is coming under pressure from environmental authorities to comply with the pollution and discharge legislations. Thus, the cleaner and safer technologies were designed to solve the pollution. It is common knowledge that use of enzymatic processes represents an interesting alternative to conventional unhairing methods. However, enzymatic unhairing was not widely used at the moment due to the reproducibility of enzyme production and performance. Thus, the auxiliary unhairing agents were used in the enzyme depilation according to the unhairing mechanism.The paper was involved into three parts. At first, two kind of proteinase 1398 and NOWOLASE PE were selected from a range of enzyme classes for their high activity in the alkaline environment. A more subtle approach would involved enzyme kinetics when they assisted with the sulfide or hydrogen peroxide. The results showed that the enzyme activity of bacillus 1398 cooperated with the sulfide or hydrogen peroxide decended only in the first hour, while retained stable higher activity after that. And hydrogen peroxide can prolong the PE enzyme activity.Based on these observations, the optimal condition undertaking auxiliary enzymatic unhairing were presented include A: 200u/g enzyme 1398 cooperated with 0.2% NaHS and B: 150u/g NOWOLASE PE cooperated with 3% H2O2. The comparison of the unhairing effect of the enzyme treated and lime-sulphide treated pelts have been studied and these results along with the physical testing data for the strength propertied of the leather are presented in this paper. It can be concluded that the pelts treated with auxiliary enzymatic unhairing have better mechanical property.The goat wool that was the byproduct recovered from the auxiliary enzymaticunhairing would be chemically degraded into polypeptide in this paper. The degradation of wool or hair by hydrogen peroxide and sodium hydroxide was studied, and the suitable degradation conditions of wool were obtained. The SEM was used to show the degradation progress of goat wool.