Biomaterial based shrink resist treatment of wool fabric: A sustainable technology

Abstract

Shrinkage in the wool fabric is a practical limitation with reference to its dimensional stability, mechanical properties, and service life. The conventional processes of shrink resist finish to the wool fabric are not eco-friendly and they also deteriorate the fabric quality. This study reported an effective and eco-friendly treatment to impart shrink resistance to wool fabric. The sequential combination of enzymes followed by polysaccharide-based biopolymers obtained good shrink resistance and retained the original attributes of the wool fabric. The fabric was initially treated with laccase and protease enzymes separately. Following enzyme, fabrics were coated with three polysaccharide biopolymers (chitosan, wheat starch, and gum arabic) using the pad-dry-cure technique. The protease-chitosan combination showed the least area shrinkage (3.57%) as compared to the untreated fabric (16.37%). The effectiveness of the treatment was evaluated and validated on wool tops using the felt ball density test. The treated fabrics were characterized using FE-SEM, EDS, and FTIR. The tensile, frictional, and bending properties were analyzed against the untreated fabric. Except for friction, tensile and bending properties remain unaffected after the shrink resist treatment. The combination of treatment retained similar whiteness and also reduced yellowness of the wool fabric. A sustainable approach of biological macromolecules-based shrink resistance treatment has an advantage over the conventional chlorination process regarding eco-friendliness, yellowness reduction, and better handle of the wool fabric at comparable shrinkage.