Improvements in or relating to crimping cellulosic yarns

Crimped yarn is produced by temporarily high-twisting e.g false-twisting, heat setting and back twisting and/or intertwisting one or more chemically modified natural cellulose textile e.g. cotton, yarn(s) or roving i.e. yarn &c. of natural cellulose which has been partially esterified and/or etherified e.g. by acetylation, cyanoethylation or benzylation, with retention of the fibre structure of the yarn, so as to increase the thermoplasticity of the yarn. Heating means for setting the yarn may comprise an electric coil which heats the air in a tube through which yarn passes, a box with heating coils through which yarns pass at different points, or a metal contact surface. The crimp may be fully developed by immersion of skeins of yarn in hot water under tension-free conditions.