Enzymatic scouring of various fabrics

Abstract

Prior to dyeing, a fabric is required to scour in a chemical solution in order to remove the impurities and to improve the fabric absorbency. A conventional scouring is usually conducted at high temperatures (80-100 ํC) and produces a chemical waste pollutant. In this work, various enzymatic scouring processes were introduced for scouring various fabrics, cotton ; polyester ; and cotton/polyester blends. Three enzymes including lipase from procine pancreas, protease from aspergillus oryzae and cellulase from aspergillus niger, were used and their activities were 15 units/g. 14,000 units/g, and 25,000 units/g, respectively. For a comparison, various conventional scouring processes were also carried in this experiment. After scouring, the fabrics were tested for the water absorbency, the weight loss, the strength, the whiteness, the dyeability, and other properties, according to the standard test methods. It was found that the enzymatic scouring results were very impressive and were comparable to the conventional scouring results. The enzymatic scoured fabrics were clean and absorbed water instantaneously. Although they lost 0.2-1.0% of the fabric weight after scouring, they gained strength and whiteness. In addition, the process made the fabric soften as well. Lipase, protease, and cellulase were less effective for scouring cotton or cotton/polyester blends when each enzyme was used alone. To successfully scour these fabrics, two scouring steps were needed by scouring with lipase, protease or lipase and protease in the first step and scouring with cellulase in the second step. Lipase could successfully scour the polyester fabric and acquire desirable fabric properties