Keratinase-protease One Bath Treatment Of Wool For Anti-felting Finishing

Wool fabric as a high-grade textile material because of its features, such as plump, crisp and warm, was long favored by people. However, it can easily become felting due to its special scale structure, and lead to difficult dyeing and finishing for textile processing. Protease acting on wool fiber, can catalyze the hydrolysis of the peptide bond, is considered to be the most promising process which can replace the traditional chlorination-resin anti-shrinkage finishing process. However, the outer scales of wool consist of many keratins containing high amount of cystines, and there is no degradation from protease, so it is necessary for oxidation or reduction pretreatment of wool, which leads to environmental pollution.Keratinase is a kind of protease having specific degradation ability to keratin. It could be producted from fungis, actinomycete, bacterias or other microorganisms, and can degrade keratin substrates, such as animal hair, person hair, feather, scales and nails. Therefore, it is widely used in the feed, medicine, food, leather and other fields.A novel keratinase from Bacillus subtilis with protease was used to treat wool fabrics in a bath in this paper. The synergistic effect of the two enzymes and anti-felting property and other properties of wool were studied according to felting shrinkage, weight loss, strength, dyeing properties, fabric style, anti-fuzzing and pilling, whiteness and so on. Combining with polypeptide release rate curve, wool Allw?rden phenomenon, SEM, infrared spectrum and amino acid analysis, a preliminary study on the mechanism of this synergistic effect of one-bath process on the wool. MTG was used to repair the strength damage of wool in view of the disadvantage that there are too much strength loss after one-bath treatment.Experimental results showed that, compared with specimens untreated or only treated by individual enzyme, the felting shrinkage of wool fabric treated with keratinase and protease in a bath dropped significantly, which had reached machine washable requirements, and dyeing rate, whiteness, anti-fuzzing and pilling performance increased, but the fabric weight loss was larger, strength and K/S reduced.UV spectrum of the hydrolyte solution showed that one-bath process could effectively improve the polypeptide release rate, and protease had no obvious effect on the structural stability of keratinase. Wool Allw?rden phenomena and wetting test results showed that the lipid on scales had been basically removed. The result of SEM showed that wool scales had been basically stripped. Infrared spectrum analysis indicated that one-bath process could oxidize cystine to cysteic acid. Amino acid analysis showed that the majority of the amino acid content of wool decreased after treatment. These results indicated that keratinase could promote protease to degrade wool scales, and the synergistic effect of the two enzymes was able to remove wool scales effectively, as well as a significant modification on wool.MTG could repair strength loss of the wool fabric after one-bath treatment, and gave a further decline in felting shrinkage of fabric, also let wettability and dyeing performance be further improved.