GB745337A - Improvements in or relating to the production of crinkled thermoplastic fully synthetic yarns - Google Patents

Abstract

745,337. Crimping yarns. MOULINAGE ET RETORDERIE DE CHAVANOZ. May 26, 1954 [June 19, 1953], No. 15602/54. Class 120 (3). A thermoplastic yarn, e.g. of nylon or polyacrylonitrile filaments, is crinkled by passing it through a setting zone, applying false twist to the yarn in a twisting zone after emerging from the setting zone and while unconfined between the zones to cause the twist to feed backwardly in the yarn into the setting zone where it becomes set therein and to be removed again after the yarn passes the twisting zone, the yarn being heated in the setting zone by radiation from a hot body or by infra-red radiation or by highfrequency dielectric heating. As shown, a yarn 8 passed through a stretching device 2 is taken up by a delivery roll 3 and presser roller 9 and travels over a roller 10 and eyelet 10<SP>1</SP> between which the yarn passes in contact with a curved metal body 11 through the interior of the casing of which a hot liquid e.g. a mineral oil, thermostatically maintained at a temperature exceeding 200‹ C. but below the melting point of the yarn in a boiler 12, is circulated via ducts 11a and 11b by a pump 13, excessive heat losses being prevented by a reflecting cover piece 11c ; the yarn then passes into a rotary device 14 whereby it receives false twist in the part of the yarn 8 which, being in contact with the body 11, is therefore fixed, and is taken up by a winding bobbin driven from a roller 15. The rollers 3 and 15 are driven from a main shaft A by gear systems B, C, 7, 6, 5, 4 and D, E, 20, 19, 18, 17 at such relative speeds as permit a predetermined constant shrinkage of the yarn.