GB931479A - Apparatus for drawing textile filaments - Google Patents

Abstract

<PICT:0931479/IV(a)/1> Apparatus for drawing textile filaments comprises means (e.g. rolls 12, 13 one of which is positively driven) to supply textile filaments from a source at a predetermined speed, a cylindrical draw roll 15, preferably of metal, adapted to be driven (16, 17) so that the filaments normally being supplied to it are under considerable tension, said draw roll carrying a plurality of polished surface strips 19 and a plurality of roughened surface strips 18 on the yarn engaging peripheral area thereof, said strips being substantially parallel and extending axially of the said draw roll, the polished strips and the roughened strips following one another consecutively about the periphery of the said draw roll, the total surface area of the polished strips constituting 50-80%, preferably 60-75% and especially 65-75% of the total yarn engaging peripheral area of the said draw roll, and a separator roll 20 mounted adjacent to the said draw roll in spaced relationship therewith and positioned so that the axis of the separator roll is disposed at a slight angle with respect to the axis of the draw roll in order that the filaments normally progressing around the draw roll and the separator roll will describe generally a helix, the convolutions of which are spaced apart. Desirably, the draw roll carries an equal number of polished strips and roughened strips, and the total number of polished strips and roughened strips is not less than three nor more than twelve in each case. A non-rotative snubbing pin 21 may be disposed in the yarn path between the supply means and the draw roll, so as to localize the point of drawing of the filaments. The apparatus may be used for the drawing of filaments of conventional cross-section, or of multi-lobal filaments. Specified filamentary materials include polyethylene and polypropylene, polyurethanes, vinyl acetate/vinyl chloride copolymers, copolymers of vinylidene with a minor proportion of mono-olefinic compounds, homopolymers of acrylonitrile, copolymers of acrylonitrile with a minor proportion of at least one mono-olefinic compound and polymer blends containing combined acrylonitrile in a major proportion; vinyl chloride/acrylonitrile copolymers, linear polyesters of aromatic dicarboxylic acids and dihydric compounds, e.g. polyethylene terephthalate and the polyester derived from terephthalic acid and bis-1,4-(hydroxymethyl) cyclohexane, linear polycarbonamides, e.g. nylon 66, nylon 4, nylon 6, nylon 610, nylon 11 and fibre forming copolymers thereof. Filaments show less tendency to cling to the surface of the roll than in the case of a polished roll, and less slippage than with a matte roll.