Thesis Details

Thesis Title: The effects of cellulase enzymes on the physical and aesthetic characteristics of woven viscose rayon and tencel
Thesis Author: Tonya Spears Strickland
Abstract: Cellulase enzymes are widely used in the textile industry for garment wet processing of denim goods to obtain a "washed down" look characteristic of stone washed garments. Studies conducted on denim and other cotton fabrics have revealed that treatment with cellulase enzymes results in a softer fabric with improved appearance. It seemed reasonable that since cellulases can impart improved aesthetic characteristics to cotton, that they may also provide benefits for other cellulosics like rayon and Tencel. Thus, this study was designed to analyze the effects of cellulase enzymes on the physical and aesthetic properties· of viscose rayon and Tencel. Dyed, unfinished fabrics were subjected to enzymatic treatment in a Unimac garment washing machine. The trials were conducted with three different acid-stable cellulase enzymes at medium and high activities for 60 and 120 mil)utes. The fabrics were then analyzed for improvements in aesthetics and deterioration in physical properties. Aesthetics were assessed using subjective hand evaluations color loss data, and a subjective evaluation of surface appearance on the Tencel. Physical properties, after enzyme treatment, were evaluated using weight loss, tensile strength, and tearing strength data. The rayon fabric appearance was affected by enzymatic treatment, but little tensile strength deterioration occurred. Only tearing strength was negatively influenced. The fabric acquired a "washed down" look typical of denim fabric. This look might be desirable for casual garments. The softness of the fabric, however, was not drastically improved. The panel of judges did determine that an increase in reaction time improved the hand; however, this would require a time consuming treatment that may only slightly improve the hand and cause significantly more color loss. The appearance and physical properties of the Tencel fabric were greatly changed by enzymatic treatment. Substantial tensile strength losses of up to 50% were obtained; however, the treatment dramatically improved the fibrillation tendency of the fabric. Of course, the most improved appearance was obtained on fabric that lost half its strength. Enzymatic treatment on Tencel could prove very valuable if the proper compromise can be made between strength properties and aesthetics.