Study On Techniques And Mechanism Of Biological Enzyme Pretreatment On Cotton Fiber

Colored cotton roving had a special processing technology, which was different from the normal cotton fiber. While the colored cotton roving was scouring with the biological enzyme, the advantages of the enzymatic scouring could bring into full play. So that it was very useful to study about this technique. In this paper, an alkaline pectinase produced by Bacillus sp.WSHB04-02 and a cutinase produced by T.fusca WSH03-11 were been choose and been used on the scoring of the cotton fiber. The techniques and mechanism of biological enzyme pretreatment on cotton fiber were studied by analysis weight loss percentage, removal percentage of pectin, removal percentage of cotton wax, tensile strength and dyeing properties of the treated fibers.In the process optimization of the alkaline pectinase, the effect of pH value, treatment temperature, enzyme concentration, treatment time and the removal percentage of pectin were studied. The result found that the suitable technological conditions were just like that: pH value 8.5, treatment temperature 55℃, enzyme concentration 150U/L, treatment time 45min.At that moment, the removal percentage of pectin were arrived at 80%. Then we found that the removal percentage of pectin could be increased with the increase of the cutinase dosage in the compound enzyme as they were been used to scour the cotton fiber. The suitable concentration of the cutinase was 200U/L. While the concentration of the nonionic surfactant TX-10 was ranged from 0 to 0.9g/L, the removal percentage of pectin could be increased with the increase of the TX-10, and the suitable concentration of the TX-10 was 0.5g/L.The scouring effects of the self-made enzyme and compound enzyme were analyzed by comparing with the Bioprep 3000L and alkali scouring. As a result, the treatment effects of the self-made enzyme were similar to the Bioprep 3000L. In comparison with alkaline treatment, enzymatically scoured cotton fibers had lower weight loss, strength loss and removal percentage of cotton waxes, but similar removal percentage of pectin and dyeing properties. There were much cotton waxes were residue on the surface of the cotton fiber ,while it were treaded with the enzyme, which made the hand feeling of the fiber was very soft. And it was favorable for the spinning of the colored cotton roving. The scouring efficiency of the fibers treaded with the compound enzyme was much better than that of the single enzyme treatment and the K/S value of these fibers after dyed with three kinds of dyes were almost the same with that of the alkaline treatment.The change of the impurity on the surface of the cotton fiber, as well as the mechanism of the enzyme scouring were studied in the comparison of the alkaline treatment were studied by the method: the change of the color of peptic and cotton wax, FT-IR ATR, SEM. The result devolved that the majority impurity on the surface of the cotton fiber was removed out ,but minority residue after the fiber treaded with the enzyme. And the scouring efficiency of the fibers treaded with the compound enzyme was much better than that of the single enzyme treatment. The synergistic effect was existed between the pectinase and cutinase in the compound enzyme system. In comparison with"peeling effect"of the alkaline treatment, which had selectivity in the removing of the impurity, the bioscouring to the cotton fiber was mainly due to the"selectivity removing effect"of the enzyme, so the enzymatic ally scoured cotton fibers had lower weight loss than the alkaline treatment.