The Effect Of Cellulase Treatment On The Handle Of Hemp Fabrics

Cellulase can permeate amorphous regions, making them expand. And with the effect of CBHS and EGS, cellulase can also erode slight fiber crystals, change fibers’internal construction, reduce the fibers’internal stress and make permanent deformation in the fibers, which finally result in the improvements of fabric performance and handle. Based on single-factor experimental design and orthogonal experimental design, the optimum cellulase treatment technology and the mechanism of cellulase treatment for hemp fabric were studied in this thesis. The effect of cellulase treatment on the hand of hemp fabric was studied. Based on carrying out the factor analysis and cluster analysis, an evaluation system for hemp fabric finishing was set up.By testing the FPBT which can approximately reflect the activity of cellulase and the weight loss caused by cellulase treatment of hemp fabric, a similarity of attribute trend had been discovered. It suggested that it was necessary to take the weight loss into consideration. So when the tensile strength of hemp fabric meets our demands, both cellulase activity index and weight loss can be used to evaluate and control cellulose treatment conditions.First, one-factor test will be used during the cellulase finishing process, then adopted Duncan Multiple comparison to analyze factors which will have an effect on the cellulase treatment by multiple range analysis. And some differences between level effects whicb have an influence on the cellulase treatment will be found out, so every factor level can be made. After that, we will use orthogonal, taking weight loss, tensil strength and bending length as indexs, analyzing the best technic of enzyme effect on finishing process. Here the weeknesses of Visual range analysis and variance analysis are revealed, so we futher used fuzzy comprehensive evaluation and decided the best technic was:cellulase concentration:14%, temperature 55℃, pH 5.0, time 55min.The Rigid Performance and draping of hemp fabric was enhanced after finishing of cellulase, however, the crease recovery was decreased. From the pictures of SEM, we can see, after cellulase treatment, the hairiness of the fabric was reduced obviously. Because of the hydrolysis of cellulase, the space between fibers was enlarged and the diameter of the fiber became much thicker, which directly resulted in the thicker fabric. Besides, it is also noticed that after the process, tensile strength was decreased, which espcially determined by temperature and pH.In this thesis reveals that many performance of hemp fabric was improved after cellulase treatment, such as, the moisture permeability, air permeability, wicking property and evaporating property. Although as cellulase technic factors changed, every index didn’t turn out consistency, the fabric had a great change before and after cellulase treatment.Here KES-F was used, and 16 basic mechanical property indexs were obtained when tested in different cellulase treatments, that is, tensile, shearing, bending, compression, surface, thickness, mass and other low stress mechanical properties, on one hand, cellulase is helpful to improve tensile properties, increase compression recovery, recduce bending rigidity and surface friction coefficient of hemp fabrics, on the other hand, the fabic become much easier to be deformed, and much harder to be stretched straightly. It is obvious that the shear, twist and surface property of hemp fabric was better than before.Through factor analysis and correlation analysis of fabrics handle index, six main factors represented handle of the hemp fabrics were extracted from 16 components, that is, aberration coefficient, fullness, actor stiffness, rigidity, tensile recovery rate and smooth roughness. Cumulative extraction sums of squared loadings reached 90.568%. In other words, it is reasonable and valid to extract those components to represent most indexes because they can express most information of the indexs, only have less informtion lost. Furtherly, named and explained those components, and though components’marks to evaluate and analyze these tested farics.By cluster analysis, it was told that the original hemp fabric is beyond other fabric which is dealt with cellulase. It means cellulase treatment does have an effective influence on changing the handle of hemp fabric. According to Cumulative extraction sums of squared loadings, which is indispensable to know the weigh of every component in evaluating the THV, we got the final scores, and regarded No 02 and 03 fabric to be a member of a particular class. In fact, it is similar to decide which the optimum cellulose treatment technology during the cellulase treatment. This thesis combined qualitative and quantitative analysises, well expressed the effect wich cellulase treatment took on the hemp fabrics, and the influence degree of follow-up super-softening as a pretreatment as well.