GB995577A - Improvements in or relating to drawing synthetic yarn - Google Patents

Abstract

995,577. Drawing synthetic yarns. BRITISH NYLON SPINNERS Ltd. April 10, 1964 [April 24, 1963], No. 16092/63. Heading B5B. Synthetic yarn having occasional knotted joints is drawn in the solid state by forwarding said yarn from one or more feed rolls to one or more draw rolls revolving at a greater peripheral speed than said feed rolls, the yarn passing round a snubbing pin on its way from the feed rolls to the draw rolls, slowly lengthening the yarn path between the feed rolls and snubbing pin by conventional mechanical means prior to the approach of a knot and by the same means suddenly releasing the reserve of yarn thus accumulated by allowing the yarn to return to its original unlengthened path just before the knot reaches the drawing zone. Yarn which may be so drawn includes stereospecific polypropylene, polyethylene terephthalate polyacrylonitrile, polyethylene and polyamides, especially polyhexamethylene adipamide yarns of 800 denier or over. In Fig. 1 the yarn path between idler pulleys 5 and 6 is lengthened by rotating the disc 1 clockwise, and drawing action is temporarily suppressed by allowing the disc to turn back anti-clockwise until the yarn assumes the shortened path shown by the broken line 7. In Fig. 2, the yarn path between idler pulleys 9, 10 is lengthened by raising the plunger 7. The operation of Figure 3, which has a triple plunger, is similar. In Fig. 4 yarn path is lengthened by lowering the pivoted arm so increasing the distance between the pulleys 22, 23 and pulleys 19, 20, 21. In Fig. 5, turning the peripherally grooved eccentrically mounted disc 25 varies the path of the yarn. In Fig. 6, yarn path is varied by raising and lowering the spindle 30 on which is mounted a truncated cone 29. All forms of apparatus may be operated manually, or preferably, automatically, in conjunction with knotdetecting devices. Specification 956,992 is referred to.