Study and application of an enzymatic pool in bioscouring of cotton knit fabric

Grey cotton contains between 4-12% non-cellulosic impurities. The removal of these impurities is generally carried out by alkaline washing at elevated temperatures which may cause damage to the cellulose fibre and generate an effluent with a high environmental impact. An alternative approach is the use of bioscouring, with enzymes specifically removing the impurities under mild conditions of pH and temperature. In this study, the effect of a commercial enzymatic pool (cellulase, lipase, and pectinase) on the bioscouring of 100% cotton knit fabric was evaluated. The effect of each enzyme and the interaction between them were evaluated with the aid of an experimental design and the characterization of the treated fabric (weight loss, degree of whiteness, degree of pectin removal, and hydrophilicity) was performed. The combination of the three enzymes on bioscouring led to the best results in terms of degree of whiteness (25.0 degrees Berger), pectin removal (87%), and hydrophilicity (14s). A comparison between the enzymatic treatment and the scouring confirmed that bioscouring can be as effective as the conventional process, being more environmentally sustainable because it occurs at neutral pH and consumes less water and energy.