| 摘要 |
Yarn, e.g. of polyhexanethylene adipamide, polyethylene terephthalate, or polypropylene, is "bunched" i.e. crimped by compressing it in the direction of its length, by tensioning the yarn when subjected to heat and then passing it through a crimping zone where it is again heated whilst and/or after being crimped. The tensioning may be such as to stretch or permit a controlled shrinkage of the yarn. A bunching zone may be bounded by a part of the periphery of a rotating wheel which impedes the yarn travel so that the bunched yarn clings to the wheel and moves with it out of the zone: the yarn is enclosed as it extends around the wheel and is heated thereat. In the apparatus of Figs. 3 and 4 (not shown) yarn drawn from bobbin 62 by rollers 63 passes over an arcuate surface 64 (controllably heated by an electrical element 65) on which the yarn is guided e.g. on a zig-zag path, to make successive passages. If yarn shrinkage is to be allowed, rollers 63 may be omitted. Rollers 19, which may rotate at the same (or higher) peripheral speed as rollers 63, advance the yarn into a groove 12 in an arcuate element 10 through a hole 21 in a wedge-shaped portion 18 thereof. Groove 12 is closed at one end by a plate 71 and is slotted to receive a toothed or serrated edge of a wheel 14 rotating at a peripheral speed many e.g. 120-460, times slower than rollers 19 to retard and move with the bunching yarn. Crimped yarn emerging at the open end of the groove is withdrawn through a tensioner and wound. In a modification, Figs. 1 and 2 (not shown) element 10 is slotted at 20 to accommodate partially the periphery of rollers 19 and the wedge-shaped bottom of the slot is bounded by arcuate faces 17 and enters the bight of the rollers. Element 10 has arcuate grooves 11 accommodating electric heating elements (not shown) and the edge of wheel 14 projects through a mouth 13 into groove 12 to which yarn is fed through a hole 21. A yarn guide block 73, rollers 19 and/or wheel 14 may incorporate electric heating elements and all heaters may be thermostatically controlled. Drives for all rotating parts of the apparatus, including winding mechanism 69, are derived from a single motor 59 and transmitted through chains and sprockets, spur gears and a reduction gear box. |
