GB730498A - Improvements in or relating to the production of crepe yarns and fabrics made therefrom - Google Patents

Abstract

730,498. Crepe yarns and woven fabrics. BRITISH NYLON SPINNERS, Ltd. Feb. 26, 1954 [March 5, 1953], No. 6119/53. Classes 120(3) and 142(4). A yarn of a synthetic linear fibre-forming polymer e.g. nylon, capable of creping on subsequent scouring or like finishing treatment, is produced by subjecting a continuous filament yarn to the successive treatments of inserting a low degree of twist i.e. less than half that finally attained ; setting the twist by an operation that also effects shrinkage of the yarn e.g. with steam at atmospheric pressure and temperatures of 190‹ F. dry bulb and 180‹ F. wet bulb after preheating for 20 minutes at 165‹ F.; sizing with a size containing a thermoplastic resinous material e.g. an aqueous solution of polyvinyl alcohol and boric acid ; inserting in the same direction as the original twist, a high twist i.e. 40-90 turns per inch ; heating sufficient to cause the size to hold the high twist but insufficient to set the twist on its own account, e.g. by steaming for 30 minutes at atmospheric pressure and temperatures of 190‹ F. dry bulb and 180‹ F. wet bulb. The yarn may be relaxed for periods of 12 and 24 hours under conditions of 50 per cent relative humidity between the first setting and sizing and after the final heating, and between sizing and high twisting, followed, in the latter case, by a period of 12 hours at 65 per cent relative humidity. When the yarns are incorporated in a fabric the size may be removed therefrom, as by an aqueous scouring treatment, to produce creped effects : in an example, a nylon crepe yarn is used in the weft of a woven fabric, the warp of which is of normal low-twist nylon yarn, two right-hand twist crepe yarns alternating with two left-hand crepe yarns ; the fabric is scoured to release the high twist and then set e.g. on a stenter.