Enzyme enhanced bleaching and depigmentation of wool and specialty animal fibres

This paper deals with the use of enzymes as a tool for reducing the environmental impact of strong oxidative processes of the textile industry, such as bleaching and depigmentation of animal hair. “Bio-bleaching” of wool tops, previously subjected to shrink resistant treatments, and bio-depigmentation of cashmere and dark camel fibre samples, were carried out on a laboratory scale. Unlike conventional oxidative treatments, proteolytic enzymes were added into the process liquors, with the purpose of improving the degree of whiteness or reducing the damage to the fibres. The specific action of these enzymes is to hydrolyse the peptide bonds of the proteins, making the fibre more susceptible to penetration of the oxidizing agent (1,2). Subsequently to the laboratory trials, the enzyme-enhanced bleaching of Basolan-treated wool tops was scaled up, in an industrial wool plant. A general improvement of the properties of the fibres was found to be associated to these environmentally friendly bio-technological processes.