Enzymatic Process for The Wool Fabric Anti-felting Finishing

Abstract

Recently washable wool is strongly requested in order to avoid dry cleaning with chlorinated solvents such as perchlomethyiene. In this paper, a new enzymatic process direction is described for obtaining machine washable wool with acceptable quality. The principle of enzymatic process is introduced. To get a good result, proper pre-treatment process and proper enzyme is discussed. The conclusion gives advice to improve the quality of enzymatic wool fabrics. Keywords: Enzyme, Wool, Fabric, Anti-felting finishing, Pre-treatment Introduction Wool is a natural protein fiber with good wearing properties [1,2], but have some short-cuts either --Wool textiles in the wet state are sensitive to felt and shrink when applying mechanical action as in the case of washing.This can be explained by the scaled fiber structure. On the fiber surface, the friction of the wool fiber in the scale direction is therefore lower than the friction against the scale direction, a phenomenon which is called the differential frictional effect [3]. The anti-felting treatment is to get the scales partly removed, or the edges from the overlapping scales smoothed.After the treatment, fabric felting tendency is reduced, which make the wool costumes washable. For this purpose, three anti-felting processes are commercially practiced [4][5][6][7][8]: subtractive (oxidation, reduction), additive (synthetic resin layer) and a combined process (e.g. chlorine/ hercosett process). However, these processes are the same in using strong oxidants, thus cause the contamination of wastewater and change the natural wool character to a more synthetic handle. The necessity to use more environmental friendly processes leads to the replacement of conventional chemical treatments by enzymatic ones. Enzyme is a biocatalyst, it can act stably in a certain mild temperature. Compare with chemical treatments in anti-felting, enzymes have lot advantages[9,10]: Water saving. Conventional treatments need repeated rinsing to ensure no chemical residues on the fabric. In most enzymatic treatments, because it is non-toxic, rinsing often take one time, this can save plenty water and cut the production's cost. Low temperature. Enzyme often acts in mild temperature below 70 , only few enzyme is active on above 70 , ℃ ℃ while chenmical process often need a tenmerature higher than 100 . So enzyme method can save money in heat ℃ energy spent. Circulation use. Enzyme acts as a biocatalyst, it can't get consumed in the treatment, moreover, it can be used in circulation. Small mount enzymes can treat blocks of fabrics in one batch. Devices protection. Enzyme treatment act in a neutral-ph (usually 8~10), thus have little corrosion on devices.The course is mild too, there is neither any evaporative emission nor any irritant gas generated in enzymatic process. Enzyme has been researched for decades, but in wool anti-felting treatment, there are some essencial processes as latter discussed. 1. Pre-treatment As Fig.1 shows, the structure of wool scales arrays like roof tiles. In fact...

Bio-Antifelting Treatment of Wool-Fiber Based on Ficin: Improvement and Effect on Dyeing with the Reseda luteola Plant

“…Therefore, papain has a higher hydrolytic effect and leads to a lower felting shrinkage than savinase. 2,3 During antifelting, wool fabric can lose important proprieties, such as strength and weight, as was observed when comparing the felting shrinkage and strength retention between different proteases. Previous research 2,3 has shown that papain causes a reduced mass loss and achieves better strength retention than savinase, but it did not exhibit a higher efficiency simultaneously.…”

“…2,3 During antifelting, wool fabric can lose important proprieties, such as strength and weight, as was observed when comparing the felting shrinkage and strength retention between different proteases. Previous research 2,3 has shown that papain causes a reduced mass loss and achieves better strength retention than savinase, but it did not exhibit a higher efficiency simultaneously. Therefore, a higher antifelting effect could be achieved only with a high mass and strength loss.…”

“…However, there is extensive research on antifelting treatment with papain, savinase, cutinase, woolase, porcine trypsin, and others. [2][3][4][5] Because papain has a similar chemical structure to ficin, their antifelting activity may be similar. Results from investigations with papain and other proteases were compared with those in this study using ficin.…”

A Novel Application of Ionic Liquid in Improvement of The Felting Resistance of Wool

“…Modifications of wool surface morphology were conducted either by chemical degradation of the wool scales or by deposition of polymer on the scales (3)(4)(5) . A wide range of enzymatic treatments are being studied as an ecological and economical way (6)(7)(8)(9)(10)(11)(12)(13)(14) . Moreover, low temperature plasma was regarded as an environmentally friendly process to achieve the effect of an anti-felt finishing in wool (14)(15)(16)(17)(18) .…”