Determining the effect of enzymatic pretreatment on the low temperature dyeability of polyamide fabrics

In this study, by pretreating polyamide 6/elastane knitted fabrics with serine-type protease enzyme, the aim was to reduce dyeing temperatures. It is known that the elasticity of elastane fibres is damaged in dyeing at high temperatures. On the other hand, to enable efficient dyeing, it is necessary to use boiling temperatures in synthetic fibres such as polyamide, or even mild high temperature conditions, to support more uniform dyeing. Protease enzymes are enzymes that hydrolyse amide bonds, and consequently, new amine and carboxyl groups are released in fibre macromolecules, resulting in an increase in the functional group content to which anionic dyes can bind. In this study, to compensate for the loss of colour yield caused by lowering the dyeing temperature, an increase in the functional groups was provided by enzymatic pretreatment. For this purpose, the fabrics were pretreated with a commercial serine-type protease enzyme then dyed with 1:2 metal complex dyes at different temperatures. The effects of enzymatic pretreatment on colour, fastness, fibre surface characteristics and fabric strength were investigated.