GB901922A - An apparatus and a method for heating or cooling and falsetwisting of running threads or yarns - Google Patents

Abstract

901,922. Finishing yarns; thread guides. ONDERZOEKINGSINSTITUUT RESEARCH N.V. May 20, 1959 [May 24, 1958], No. 17192/59. Classes 120 (2) and 120 (3). In a method of producing yarn having a tendency to shrink and curl by passing a yarn continuously between a false-twisting device and a twist barrier in a zone between which the yarn is heated and/or cooled, the path of the yarn over a guide member between the device and barrier is reversed and the member is given a movement, or component thereof, in the circumferential direction of the yarn as it passes over the member and in the sense of the rotational movement of the yarn at the place of contact with the member due to the twisting action thereon; the guide member thereby provides a shortened yarn path without obstructing the run of the (false-) twist therealong. In the curling apparatus of Fig. 1, a multifilament yarn 1 supplied from a spool 2 passes through an eyelet 3 to conveying mechanism 4 comprising two driven steel rollers and a rubber-coated pressure roller, thence through twist barrier 5 and heating tube 6 ; the yarn is reversed by a guiding system 7, returns through tube 6, is false-twisted by a spindle 8, passes through eyelet 9 and is wound on a tube 12 on a ring twisting machine. The system 7, Fig. 3, comprises an endless steel wire 13 running on rollers 17 at a speed corresponding to the circumferential speed, in the tangential direction, of the surface of the yarn. In a modification, Fig. 4, (not shown), the wire 13 running on four rollers passes adjacent both ends of the tube 6 and the yarn is reversed around the wire twice. Another modification, Fig. 5, comprises a rod 14 and high-frequency vibrators 15 and 16 which vibrate the rod in mutually perpendicular directions ; a phase differential between the vibrators, the frequency and amplitude are so adjusted that rod 14 develops a circular vibrating condition the circumferential velocity of which corresponds with that of the wire 13 in relation to the yarn. As shown in Fig. 6, yarn 1 (leaving tube 6) passes around two free or driven rollers 20, 21, the angle of false-twist and the angle of inclination of both rollers to the direction of travel of the yarn being identical, e.g. all 45 degrees. In further embodiments (not shown) of system 7, the yarn passes (a) through a flexible tube which is bent through 180 degrees and rotating about its axis so that the circumferential speed of its internal surface is equal to the rotational speed of the surface of the yarn, or (b) over a small direction-reversing wheel rotating at a circumferential speed much greater than the linear speed of the yarn.