ES347882A1 - Process for the manufacture of a composite yarn which is provided with spaced slubs - Google Patents

Abstract

In the manufacture of a composite slubbed yarn comprising two or more component, e.g. drawn polyamide or polyester, yarns, the supply of one component is intermittently arrested, e.g. for 2-5 seconds, as it approaches a jet device, wherein all the yarns are treated with a turbulent gaseous, e.g. compressed air, stream in order to entangle them, and the tension in the other component(s) is simultaneously reduced. The composite yarn passes from the device to a ring-traveller twisting and take-up apparatus and the twist, running backwards along the yarn to a point upstream of the device, causes the yarn(s) in which tension has been temporarily reduced to wind around .the arrested (and, therefore increasingly tensioned) yarn(s) in order to form slubs. The size and form of the slubs may be varied in alternating and/or irregular, perhaps programmed manner. In the operation of the apparatus shown in Fig. 1, yarn 1 under tension passes through an adjustable disc tensioner 5, a movable eyelet guide 6, jet device 7 where it meets a yarn 8 supplied under tension by pressure roller 15 and driven roller 17. Composite yarn 9 is wound into a package on a rotating tube 11 within a twisting ring 10. When irregularly spaced pins 23 on a rotating switching wheel 22 close a circuit 20, relays 24, 25, 26, are energised respectively to actuate a lever 18 thereby separating rollers 15 and 17 and stopping the advance of yarn 8, to brake and quickly stop rotation of roller 15, and to adjust the tensioner 5 so that the tension in yarn 1 is decreased, and a stub 28 is formed. Opening circuit 20 restores the non-slubbing advance of the yarns. Slub variation is obtained by mechanically, electrically or pneumatically induced oscillatory or reciprocating movements of eyelet 30 of guide 6. In one mechanism, Fig. 3 (not shown) eyelet 30 is connected to a linearly constrained link motion which is reciprocated by engagement in a slot thereof of a pin carried eccentrically on a rotating wheel. Another mechanism, Fig. 4, comprises a reversible rack 41 driven by a pinion 42 alternately, in one direction, by direct mesh therewith and then, in the reverse direction, indirectly through an intermediate pinion 43.