Study On The Structures And Properties About Variable Cashmere Fiber By Enzyme

Cashmere, as one of the most precious animal fiber, is a high-grade raw materialsin the wool spinning industry. Chinese cashmere is the highest both in its quality andprod-uction in the world. However recent years, because of artificial selection,environ-mental change and other factors’ effect, the physical and chemicalperformance of the cashmere fiber generates variation, that brings the development ofcashmere industry great challenges. This topic,which used enzyme to process thevariation cashmere fiber, then observed the structure and tested the performance of thefiber systematically to explore more reasonable enzyme processing technic, aims toprovide reference for the environmental processing of the Variation cashmere.This study chose four kinds of environmental protection reagent: hydrogenperoxide, Keratinase, protease (Savinase), Neutral protease. Through the single factortest, confirmed the suitable pretreatment conditions of hydrogen peroxide andKeratinase.(1) The suitable conditions of hydrogen peroxide pretreatment: bathratio1:25, temperature40℃, pH8.5, time40min, Na2SiO3concentration2g/L,penetrant JFC (1g/L), hydrogen peroxide concentration20ml/L.(2) Two pretreatmentconditions of Keratinase, the condition J1: bath ratio1:50, temperature, pH value andfifty℃, time of5h, Keratinase concentration10%; the condition J2: bath ratio1:50,temperature50℃, pH8, time6h, Keratinase concentration20%.With the pretreatment conditions as one factor of it, The orthogonal experimentof the pretreated fiber was finished by the alkaline protease (Savinase) and Neutralpapain. Through the intuitive analysis found that: among the four factors that set forthe orthogonal test, significance level of pretreatment conditions on the fiber breakingstrength influence is higher, the breaking strength of wool fiber and two fine fiberwhich has been finished with hydrogen peroxide is relatively low. Therefore,compared to the treatment with hydrogen peroxide+protease, Keratinase+proteasetreatment can considerably reduce the fiber friction effect, with less damage on thestretching propertiesof fiber. Through the comprehensive score analysis of thefinished fibers, explores the optimal conditions of enzyme treatment on variationcashmere are: the alkaline protease (Savinase) concentration (owf)5%, the processingtime20min, temperature60℃, pH8.5, bath ratio1:30, pretreatment condition is J2(bath ratio1:50, temperature50℃, pH8, time6h, Keratinase concentration20%).After these treatment, wool fiber breaking strength is3.39cN, breaking elongation is31.70%, and the fracture work is14.90cN×mm, the static friction effect was18.5%, the dynamic friction effect is16.7%.Process the variation cashmere from different regions with this optimal enzymetreatment conditions, test the tensile properties and friction of the modified typicalcashmere fiber. Through analysis, it shows that there are some differences among thevariation cashmere that from different regions after the treatment in the strong stretchproperties and the friction performance. But after enzyme treatment, both of the woolfibre and the two fine fiber’s breaking strength decreased, two type fiber and shagfiber’s breaking strength changed little. After processing, the friction factor increased,while the friction effect reduced.Through the observation of the surface morphology of variation cashmere fiber,both the untreated and the treated, by the scanning electron microscope (SEM), thenuse the Fourier infrared spectrometer to test and analysis the internal structure andchemical group of the fiber. The results showed that: after processing, part of the fiberscale fall off, edge profile blurs, the height of scale decreases, and fiber surface turnsrough, a few parts have the sediment; After processing fiber amide Ⅰ take randomcoil increases, Ⅲ amide with the α helix structure decreases, random structureincreases, Ⅱ amide with little change, disulfide bond have fracture. Through theobservation by microscope on pulp cavity of the two-type fiber, it shows that enzymetreatment has no obvious influence on internal medullary cavity structure of thetwo-type fiber.