Patent GB-783491-A (GB)
Title: Method and apparatus for crimping filaments
IPC: D02G1/02
Filed: 1953-05-21
Abstract: 783,491. Crimping filaments; twist tubes and driving arrangements therefor: UBBELOHDE, L. May 21, 1953 [May 23, 1952; March 25, 1953], No. 14319/53. Classes 120(2) and 120(3) A process for crimping continuous filaments of synthetic thermoplastic material by means of temporary false-twist comprises the steps of passing a tow or bundle of filaments into a softening zone wherein the filaments are rendered plastic by heating, then through a solidifying zone wherein the filaments are resolidified by cooling, and subsequently through one or more false-twisting devices, in such a way that the false-twist runs back along the filaments through the solidifying zone into the softening zone and is received by the filaments in the softening zone and set in the solidifying zone, and finally removing the false-twist. Wetting, and/or impregnation of the filaments with setting agents at any suitable stage, may occur in orderto increase the curliness of the filaments. The heating may be effected by gaseous or vaporized media e.g. hot air or superheated steam, dielectrically, or by ultra-sonic or infra-red irradiation. Several bundles having had false-twist in the same or opposite direction may be intertwisted after removal of the false-twist and, optionally after receiving slight reverse twist. As shown in Fig. 1 a bundle 1 of filaments is fed off a supply 2 by driven rollers 3 into a heating zone 4, (where the filaments are softened and receive the twist running back from the false-twister) a cooling zone 5, (where the twist imparted to the filament is set therein by the solidification thereof) a twist-imparting zone 6, thence through driven rollers 7 to be collected on a bobbin 8 or on a revolving spindle of twist is required; passage through the zone 4 may be immediately preceded by passage through a preheating zone, Fig. 2 (not shown), wherein the filaments are not receptive of twist and are thus more readily heated. The filaments collected beyond the rollers 7 may be reheated and cooled to increase the contraction of the filaments and hence their elasticity. The false-twist may be imparted by twist tubes, one example 30 shown in Fig. 7 comprising an axial bore 31 intersected by a transverse ;bore 32 through which a bundle 1 is passed, and the false-twisting apparatus comprises at least one pair of opposed surfaces moving at equal speeds and in opposite directions, e.g. two or more runs of a single endless belt. Figs. 3, 4 and 4a show a device whereby rolling movement of twist tubes 14 is effected by two runs of a belt 15 driven as by rollers 16 and passing over displaceable rollers 17, guide plates 18 or idler (pressure) rolls 19. The apparatus of Figs. 5 and 5a employs four belts 21, 22, 23, 24, passing around roller 16 and enveloping the tubes 14 in such manner that adiacent tubes impart opposite twists. Figs. 6, 6a, 6b, 6c illustrate apparatus in which twist tubes 14 are roller between a roller 25 or 25a, 25b, or 25c, and a belt 15. The twist tubes and the bundles may be maintained in position and separated by guide means such as rods, forks, combs, or rolls (not shown). Specifications 783,492 and 783,493 are referred to.