Valley-filling and peak-shaving: A dual-effect and controllable enzymatic approach for achieving machine-washability of dyed wool textiles as a sustainable alternative to dry cleaning

In recent years, with the advancement in the consumer market and industrial trends, wool has shown new vitality in the fields of outdoor sports apparel and smart wearable textiles due to its unique properties. However, the inherent felting characteristic of wool leads to undesirable dimensional shrinkage after machine washing, which necessitates that wool products be dry-cleaned. Conventional dry cleaning solvents like perchloroethylene are considered to be carcinogenic and detrimental to the environment. Factories usually adopt the chlorination process to manufacture machine-washable wool textiles, which may release harmful adsorbable organic halides (AOX) to the environment. Herein, we developed a “valley-filling and peak-shaving” dual-effect enzymatic anti-felting strategy as an ideal sustainable alternative. The pre-filling not only inhibits the protease from penetrating the fiber interior but also enhances its adsorption on the fiber surface. Hence, the compound proteases, possessing efficacy in degrading keratin-rich scales, primarily hydrolyze the fiber surface. This selective hydrolysis endows these textiles with machine-washability while preserving their original mechanical properties and color attributes, achieving a felting shrinkage of 5.06 % and an increase in tensile strength of 0.27 % for wool fabric. In summary, we present a green and feasible enzymatic approach to eliminate shrinkage, thereby facilitating the diversified application of wool products.