A Sustainable and Effective Bioprocessing Approach for Improving Anti-felting, Anti-pilling and Dyeing Properties of Wool Fabric

The surface of wool comprises overlapping cuticle scales that hinder processing of the fiber. Enzymatic modification is widely used for damaging or removing cuticle scales in wool. However, common protease enzyme has poor hydrolysis ability on wool (85 % are keratin) due to specificity of the enzyme, resulting in low modification effect on wool. A novel and effective method was developed to circumvent this limitation resulting in wool with excellent anti-felting, anti-pilling and dyeing properties using proteinase K, a special protease that can effectively degrade keratin. Analysis showed that proteinase K had high affinity for keratin, making it more inclined to hydrolyze the scale layer than the cortical layer compared with commercial proteases Esperase 8.0L and papain. Area shrinkage (4.7 %) of samples treated with proteinase K was significantly lower compared with the area shrinkage of untreated samples (18.5 %), thus complying with machine-washable requirements. A pilling-free modified fabric was obtained with a small enzyme dosage (8 U/g) and the percentage of dye uptake of the wool fabric increased by 100 % compared with original fabric.