| The unique scale layer structure of wool fiber will bring various inconveniences to the daily use and dyeing and finishing processing of wool,such as wool felt shrinkage,hindering dyeing of dye,etc.,so the scale layer of the wool often needs to be shripped off.Proteinase has gradually attracted attention in recent years due to simple operation and good biocompatibility and environmental protection.However,most of the proteins in wool belong to keratin,so the efficiency of protease on the wool scale layer is very low.Proteinase K has extensive substrate specificity and high enzymatic activity to effectively degrade keratin,so it can be applied to wool processing to achieve exfoliation of the scale layer.In this paper,we systematically study the function of proteinase K on wool scale,explore its mechanism of action and optimize its process,and have some application prospect in the field of wool scaling.Main work of the paper are as follows:(1)Explore the mechanism of action of proteinase K on wool fiber scaling.The mechanism of action of proteinase K was analyzed by substrate specificity test,UV absorption spectroscopy,thiol content test,and XPS.The results show that proteinase K has a strong ability to degrade soluble keratin but cannot break the disulfide bond,and it cannot effectively peel off scales when treated with proteinase K alone.So we pretreat wool fiber by the role of the keratinase which can open the disulfide bond,then we treat wool by proteinase K.The results found that the disulfide bond of fiber surface fracture after keratinase pretreatment,making the protein chain loose,and exposed peptide bond content increased,increased the protease K and reaction substrate contact,thus improve the efficiency of protease K,effectively remove fiber surface scale layer.(2)Optimization of scaling process and comparison of application performance.First,test the enzymatic properties of Keratinase and proteinase K,explore the influence of temperature and p H value on the enzyme activity.On the basis of the felt ball density and break strength index,explore the influence of the two enzymes under different conditions on the effect of the scale,such as treatment time,treatment temperature,p H value and enzyme dosage.The optimal process was keratinase concentration 0.3 g / L,treatment time 6 h,treatment temperature 50℃ and p H value 8.5;protease K concentration 30 u / g,treatment time 1.5 h,treatment temperature 50℃ and p H value 8.0.The application performance was then compared with other methods by testing the directional friction effect,K / S value,whiteness,and pilling resistance.The results show that the anti-felt shrinkage performance of treated wool fabric is significantly improved,better than chemical pretreatment + protease treatment,and similar to chlorination effect;the K / S value can be above 33,the dyeing rate is significantly improved,and the fastness of each dyeing reaches level 4-5,and the anti-bulb performance reaches level 3. |
