IE35701L - Producing crimped yarn - Google Patents

Abstract

1372872 Crimped yarns BAYER AG 7 Oct 1971 [8 Oct 1970] 46709/71 Headings D1F and D1W A process for producing a textured elastic crimp yarn made up from continuous synthetic filaments comprises prestretching a yarn, heat treating the yarn in a heating unit, false-twisting the yarn; further stretching the yarn at a rate of travel of 300-800 metres per minute, further heat treating the yarn in the heating unit, under a filament tension from 50-99.5% lower than in the first heat treatment, and taking-up the yarn. Referring to the Figure, the yarn is stretched between rolls 1 and godet 2 and is then passed in contact with heater 3. The heated yarn passes through a false-twisting unit 4 to be further stretched by godet 5 before passing to a guide 6 to contact the heater 3 a second time. The yarn is then taken-up on on a package 8 and may pass a treatment unit 7. The filaments used are preferably polyamide or polyester filaments. The yarn of the invention has a latent crimp of from 80 to 200 turns per metre, a shrinkage in boiling water of 4-5%, a percentage crimp of substantially 60%, a latent arc count per centimetre of 8-15, and over its entire length, alternating sections of S-twist and Z-twist of varying length. The twists in the S-twist and Z-twist sections are preferably in the range 10-300 turns per metre. [GB1372872A]