GB1364371A - False-twisting process - Google Patents

Abstract

1364371 False twisting process and apparatus friction twisting HEBERLEIN & CO AG 8 June 1972 [8 June 1971] 26831/72 Headings DID and D1F In a process for false twisting a yarn, the yarn 1 is moved in contact with at least one moving friction member 2, and tensioned such that a force component is exerted normal to the friction surface in contact with the yarn, the yarn tension being controlled whereby reductions in the degree of twist imparted to the yarn result in an increase in yarn tension thereby increasing the frictional force between the friction surface and the yarn and a compensating increase in the degree of twist imparted to the yarn. The friction member is preferably a roller which may be barrel-shaped or be in the form of a disc with a rounded edge. In an alternative embodiment several discs are arranged one above the other with the edges partially overlapping. Alternatively the friction surface could be on the inner circumference of a tube provided with flared entrance and exit apertures. In the preferred embodiment of friction member the external surface of a disc 2 is provided with raised friction tracks 4 which in use are at an angle to the direction of yarn movement. In the event of slippage occurring between the yarn and the surface, the tracks cause a frictional force component to act on the yarn in the direction opposite to that of yarn movement which thereby increases the yarn tension P 2 and thus the force normal to the friction surface. In a further embodiment, a raised strip contiguous with the tracks extends around the member 2 at the maximum diameter thereof. The yarn is heated during the false twisting process.