GB1025387A - Processing of yarns - Google Patents

Abstract

1,025,387. False twisting yarns. FLUFLON Ltd. Oct. 30, 1962 [Nov. 2, 1961], No. 40902/62. Headings DID and D1F. A method of processing yarn having thermoplastic qualities to produce a port treated torque stretch yarn comprises the steps of continually advancing said yarn at a predetermined speed of travel through a false twister, controlling the tension of said yarn during the twisting and reverse twisting, heating the yarn while it is twisted to a predetermined treatment temperature correlated with the yarn tension, and controlling the heat loss from the yarn subsequent to the heating to prevent cooling of the yarn to ambient temperature as it is reverse twisted, so that the yarn contains sufficient residual heat to be correlated with the tension therein to effect a port treatment of the yarn continuously with its initial production. As shown yarn passes through a pre-tensioner 12, guide 13 which is oscillating to prevent a groove wearing in the rollers 15, radiant heater 16, around roller 25 of false twister 21 driven for example by a belt, through rollers 26 and thence to take-up 28. The tension in the yarn on either side of the roller 25 is controlled by the rollers 15 and 26 and by whether roller 25 is positively driven or braked. The temperature of the heater 16 is maintained at a predetermined temperature dependent on the ype of yarn so that the yarn temperature is preferably within 20‹F. of, but not less that 40%- in ‹F. - below the melting point of the yarn. A suitable port treatment temperature is obtained by varying the distance between the heater 16 and roller 25 by adjusting the position of the heater on the frame 17 and perhaps by putting the roller 25 on the other end of the false twister at 24<SP>1</SP>. Alternatively the roller 25 can be replaced by a "hair pin" wire Fig. 2 (not shown) of low heat conductivity, around the bight of which the yarn is wrapped and which can project into the heater. In other embodiments the false twister comprises circular friction tube Fig. 3 (not shown); or two inclined counter rotating discs 74, Fig. 7 (not shown), having yarn engaging annuli of low heat conductivity, the discs either being geared to a belt driven spindle, or each disc having its own belt drive with the spacing between the discs being adjustable; or two parallel, counter rotating discs mounted on a non rotating spindle 83 and driven by a belt. The take up means 28 may be replaced by a ring twister take up and the radiant heater by a contact heater Fig. 4 (not shown). A tube may extend from the heater to the false twister. The yarn obtained may be plied with a similar or dissimilar yarn, the plying possibly occuring when adjacent yarns are wound on the take-up package when a ring twister is used.