Lubricants based on fatty acid ester (FAE) mixtures are widely used in the textile industry, e.g., in spin finishes applied during the production of synthetic fibres, or in sizes added to fibres before weaving. FAE lubricants can significantly impact the dyeing quality of a textile due to their hydrophobicity and must therefore be removed before dyeing. However, the solvents currently used for their removal pose an environmental risk, and biobased solutions are thus sought. A lipase-assisted pre-dyeing treatment for synthetic fibre textiles was developed in this study. Six lipases were tested for their ability to hydrolyse FAEs from a polyamide-with-elastane textile, and all were found to be active. The conditions for the washing of lipase-treated textiles were found to be crucial for the performance of the process. Among the possible lipid hydrolysis products of tripalmitin (selected as a model FAE), only palmitic acid removal improved during washing, in comparison with the original FAE. This improvement only occurred with washing solutions containing a monovalent base. A combination of lipase treatment and washing with a non-ionic surfactant and monovalent base was found to be effective in the removal of FAEs, with a performance similar to a current solvent-based pre-treatment process.
Sousa et al. (Tue,) studied this question.