GB850230A - Method and apparatus for producing unbulked torque yarn - Google Patents

Abstract

850,230. Torque yarns; twisting machines, heating and moistening arrangements. SEEM, W. A., and STODDARD, N. J. Sept. 21, 1956 [Sept. 22, 1955], No. 28877/56. Classes 120(2) and 120(3). Monofilament, multifilament or staple fibre yarns having thermoplastic properties (including resin-treated non-thermoplastic yarns) have torque forces inserted without causing bulking. Running yarns are continuously twisted, heat-set, cooled and untwisted and bulking is avoided by having sufficient actual twist in the yarn to hold the filaments in a compact bundle and/or by falsetwisting to an extent insufficient to cause shrinking and bulking. Yarns capable of being cold drawn may be treated by applying tension adequate to draw while twisting and without greatly increasing the temperature of the yarn. After imparting torque, chemicals or sizing materials may be applied to reduce the liveliness of the yarns, e.g., a water solution of polyvinyl alcohol and boric acid with 5% of sizing, these materials being removed after the yarns have been converted to knitted or woven fabrics. The process may be carried out on a two-deck uptwister modified as described in Specification 803,106 with a tension device, false twist tube and heater on the top deck. The' lower deck may also be provided with a heater, the lower heater being energized when yarn is drawn from the false-twist spindle and the upper heater being energized when yarn is drawn from a stationary creel above the top deck. In one example, a 15 denier nylon yarn was twisted 7 turns per inch on spindles 11 rotating at 7,000 r.p.m., passed through tensioning and heating devices 13, 12 and a false-twist spindle 4 revolving in the opposite direction to the initial twist spindle at 23,000 r.p.m. and finally taken up at 1,000 inches per minute after further tensioning at a device 8. An emulsion trough 14 may contain a dye solution, a sizing liquid, or a thermal setting medium, such as urea formaldehyde resin, for application to basically non-thermoplastic yarns. Several ends of yarn may be' false-twisted at the same time and separated for use as individual ends. Specifications 773,816, 803,105, 803,107, 803,109, 803,110, 835,551 and 835,552 are referred to.