GB1293119A - Process for producing torque-stretch yarn - Google Patents

Abstract

1293119 Treating yarn E I DU PONT DE NEMOURS & CO 19 April 1971 [15 April 1970] 27056/71 Heading D1F A process for producing torque-stretch yarn in a continuous false-twisting operation, comprises (1) feeding a drawn yarn of thermoplastic polymer, at uniform speed, to a treatment zone including a symmetrical jet stream of hot fluid and a torque jet of cool fluid, (2) passing the yarn, in a false-twist configuration, along a straight line of travel through the treatment zone, first along the flow axis of the jet stream to plasticize the yarn and then along the vortex axis of the torque jet to false twist and deplasticize the yarn, and (3) withdrawing the yarn from the treatment zone with the false-twist configuration removed, at a uniform speed selected to provide a uniform tension between the jet stream and torque jet with 0.3 or 1.5 gms total tension and at least 0.015 gm./ denier. The fluid-torque jet may be of the type shown in Fig. 2 wherein a body 50 is provided with pipe-means 51 for injecting a pressurised cool fluid. A smaller bore 53 continues from bore 52. A hole 60 extends through the jet and has an open side communication with 53. The hole 60 may be in disc 59 to which is provided a handle 58 for rotation of the disc so that hole 60 communicates with slot 56 for easy string-up with yarn. When hole 60 is in communication with bore 53, pressurized fluid forms a high-velocity swirl in direct contact with the yarn. The treatment zone also includes means for contacting the yarn with a symmetrical jet stream of hot fluid, a suitable means being shown in Fig. 3 wherein a pressurized fluid enters the means at opening 67 and passes over heater 66, the heated fluid then contacting the yarn 10 in the annular opening 62. A thermocycle may be provided in the plenum 63 to regulate the temperature to which the fluid is heated.