ES314596A1 - Drawing synthetic thermoplastic yarn - Google Patents

Abstract

A process for the high-speed uniform drawing of filamentary yarns composed of thermoplastic synthetic organic polymers comprises heating yarn to a desired drawing temperature by a stream of liquid directed into the path of the yarn just prior to passage of the yarn over snubbing means arranged close to but not in direct contact with said stream. Preferably, the yarn in its passage over the snubbing means is caused to change direction sharply thereby throwing off liquid entrainedin it. The yarn may remain substantially undrawn in its passage through the liquid stream. Preferably, the liquid is one which does not attack the yarn, water being preferred, and a lubricating or other substance may be dissolved or dispersed in the water. The stream of liquid may be co-current or counter-current to the direction of travel of the yarn. Specified yarn materials include polyethylene terephthalate, nylon 66 or polypropylene. Apparatus for drawing filamentary yarns composed of thermoplastic synthetic organic polymers comprises means for supplying yarn to a drawing device, means for withdrawing yarn from the drawing device at a higher rate than the supply rate and means for collecting the drawn yarn, wherein the drawing device comprises a supply of temperaturecontrolled liquid, and means for directing the stream of the liquid into the path of the incoming yarn just prior to passing the yarn over snubbing means, whereby the yarn is raised to the desired drawing temperature, said snubbing means being out of direct contact with the liquid stream and so cause in operation a sudden change of direction of the yarn, whereby liquid entrained in the yarn is thrown off. The snubbing means may be one or a number of cylindrical metal or ceramic pins and the yarn supplying and withdrawing means may be rollers. The withdrawing roller may be heated. In Fig. 1, liquid at a required temperature is supplied through inlet 1 to directing means 2 which has the form of a truncated flume 4 mounted in container 3. Liquid flows through the narrow end of the flume across the path of entering yarn 5 just before the yarn is passed over the first of a series of three snubbing pins 6, whereon the tension is raised and drawing occurs. The snubbing pins are mounted on a carrier 7 which is attached to a cover 8 of the container 3, the whole being demountable to facilitate stringing up of the yarn. The used liquid is carried away by outlet 9 to waste or to temperature-controlled reservoirs. Spun yarn is supplied to the drawing device from package 10 by a feed roll/idler roll combination 11, optionally by way of a tension control device 12. Drawn yarn leaves the drawing device by a draw roll/idler roll combination 13 and is collected on a package 14.