Delipidisation of wool fibres and the subsequent beneficial properties of delipidised wool fibres

Abstract Wool fibres are complex matrices of proteins and fatty acids/lipids found both internally and externally. 18‐methyleicosanoic acid (18‐MEA) is covalently bound to the surface of the fibre via a thio‐ester link, and is considered one of the most important lipids as it is responsible for the hydrophobic properties of wool fibres. During chlorination, which is part of the shrink‐proofing process, many of these lipids (but not all) are removed or destroyed; however, chlorinated wool has the tendency to yellow when heated during subsequent processing or exposure to light. This paper reports a novel “delipidisation” methodology that removes more than 97% of 18‐MEA and other lipids in less than 10 seconds (without subsequent yellowing), which is a highly efficient breakthrough technology for the wool industry. Results show that the delipidised wool allows easier water‐based processing with numerous potential benefits, including lower‐temperature, faster and more efficient dyeing processes. A further benefit is that delipidised wool fabrics can be printed using a normal ink‐jet printer, giving high quality prints with very good colour fixation and definition of fine lines with much brighter and deeper colours than untreated or chlorinated fabrics. Following delipidisation and subsequent oxidative sulphitolysis, an even deposition of Hercosett (a polyamide epichlorohydrin polymer) onto the delipidised wool can be achieved, offering potential for shrink‐resistance performance. This groundbreaking delipidisation technology shows considerable potential for enhancing wool processing, with numerous benefits yet to be fully explored.