The Anti-Pilling Finishing For Knitted Wool

Knitwear of wool fiber as main raw material has the following characteristics: soft, close-fitting, warm, moisture absorbing, breathable, comfortable to wear, hence it is favored by consumers. However, because of the scale structure of wool, when worn, the fuzzy balls on fabric surface seriously affect the performance and appearance of knitwear. Therefore wool knitwear of high quality requires anti-pilling finishing.By now, there are three ways of anti-pilling finishing for wool knitwear: the physical, the chemical and the biological. The physical way is operated through etching the scale layer on fabric surface by plasma and UV radiation; the chemical way is realized by using chemical reagent to distroy the scale layer or to produce a film on top of it. The biological way is to reduce the elasticity of knitwear by bio-enzyme. The above mentioned methods are all helpful but have their shortcomings respectively, because of which, to improve the pilling resistance of wool knitwear without violating the strength and feel is still a hot topic to be studied. The purpose of this experiment is to find a new finishing technique—first appropriately destroy the scale layer without violating fiber strength by self-made resin finishing agent combined with filtrated reductant, then fix it by cross-linkable resin, thus achieve the anti-pilling goal, and barely affect knitwear’s performance.In this paper, the author first picks up sodium hypophosphite, sodium pyrosulfite, and reductant 001 from many kinds of redox finishing agents, and then optimizes the finishing process through orthogonal tests. The result shows: all the three finishing agents can improve the pilling resistance of wool knitwear, but the effects are not exactly the same. Reductant 001 works the best, the pilling resistance of knitwear finished by it ranks level 3.5. Sodium pyrosulfite is not as good as reductant 001 but better than sodium hypophosphite. Using one finishing agent alone can decrease the strength of knitwear. For colored knitwear, the process costs chromatic aberration to different extent.Consequently, this paper demonstrates that the author has synthesized a cationic aqueous polyurethane MM-1 and is applying it to the technology of anti-pilling finishing for wool knitwear. Via contract experiments against several resin anti-pilling agents on the market, the author finds out that self-made aqueous polyurethane MM-1 functions the best, it can raise the level of wool knitwear’s pilling resistance from 2 to 3.5. Moreover, among commodity resin finishing agents, M2002 is the best, but it only raises the level from 2 to 2.7.In order to better improve the pilling resistance of knitted wool and keep the minimum strength loss, chromatic aberration and feel variation. Finally, the experimenter combines the self-made resin finishing agent and several resultants, and obtain three sets of optimized combinations of finishing agents and processes. These processes can raise the level of knitted wool pilling resistance respectively from 2 to 3.7, 4, 4.1, meanwhile, hardly have any adverse impact to the strength and feel of knitwear.