Patent ID: 7493747
Filing Date: 2009-02-24
Classification: D02G

Abstract:
1. A process for producing a composite dual core-spun yarn with substantially no torque and having a central hard core covered with a dual-spun fiber covering, wherein the central hard core has an elongation of break less than 50% measured according to the methodology of ISO 2062, the process comprising: (a) bringing together two fiber slivers to form a spinning triangle; (b) feeding the central hard core in the spinning triangle between the two fiber slivers with the latter at an angle to the central core, the fed core being guided in the spinning triangle and having a Z or S twist that is overtwisted relative to the twist of the finished composite yarn; (c) controlling the speed of feeding the core in the spinning triangle to compensate for the angle between the slivers and the core and for detwisting elongation of the core; and (d) spinning the brought-together fiber slivers around the core with an S or Z twist opposite to that of the core and corresponding to about 30% to about 70% of the twist of the fed overtwisted core to obtain a composite core-spun yarn with substantially no torque.