GB742393A - Improvements in or relating to the formation of continuous filamentary tows - Google Patents

Abstract

<PICT:0742393/IV(a)/1> In forming a tow of total denier 5000 or more from filaments of a melt-spun synthetic linear polymer, a plurality of filaments soon after extrusion but after solidification are led together and fed into a compacting device comprising two coacting pressure rollers which form them into a lightly cohering tow such that the filaments are separable on subsequent processing. In the illustrated example a number of bundles of 100 3-denier freshly extruded nylon filaments are cooled by air in the normal way and, after passing through a convergence guide, each filament bundle passes through a steam conditioner tube and then over a finish-applying roll, and is then led with other bundles to form a tow of denier at least 5000. The tow, while still in a somewhat plastic condition, is then led through a funnel guide to a compacting device comprising two 6 inch diameter rollers 1 of hardened steel which are driven so as to pull a tow between them at linear speeds up to 3000 ft/min. or more. The pressure exerted by the rollers 1 must be of the order of 50 lb. On the underside of the nip of the rollers are two scraper blades 3, the upper end portions of which are urged by coil springs 5 into contact with the rollers so as to form a throat 7 and ensure the removal of the tow from the rollers and its delivery into a slowly revolving can. The blades 3, the tips 9 of which may be of copper, are adjustable for the angle at which they impinge on the rollers, for the distance from the nip of the rollers at which they impinge, and for the pressure which they exert against the roller surfaces. For these purposes, the blades are pivoted on eccentric end portions 11 of rods 13 mounted in shaped side plates 15, so that by rotating rods 13, the angle of the blades and the positions of contact of their tips on the rolls 1 can be adjusted. The pressure of the blade tips on the rolls 1 is adjusted by inserting the rods 17 connected to springs 5 in any one of the vertically spaced retaining slots 19 in the side plates 15. Each spinning machine is preferably provided with two compacting devices arranged for alternate operation in order that spinning may be continuous. The process enables the stretching and crimping of the tows to be carried out continuously by joining the leading end of one tow to the trailing end of another. Specification 742,398, [Group IX], is referred to.