Improvements in or relating to continuous filament yarn having low and variable twist

摘要

A compact multifilament, continuous filament e.g. nylon, yarn has a low unidirectional twist of less than 0.15 turn per inch variable in the same sense along its length and compensatory interfilament cohesion, as may be ensured by interlacing (but not looping) with a fluid jet and/or applying alternating twist of a net value of zero and/or applying a sticky finish which lightly bonds the filaments together, whereby the yarn has the same handling properties as a normally twisted yarn of similar constitution. The total interfilament cohesion properties may be constant along the length of the yarn. The yarn and a package thereof having tapered end portions is produced by forwarding the untwisted multifilament from a (draw) roll rotating at constant speed, thence through apparatus which augments the interfilament cohesion and assists in forwarding the yarn, and then winding into a package by a ring spindle in a build having the length of traverse stroke progressively decreasing throughout: the speed of rotation of the spindle also decreases so as to maintain constant the speed of rotation of the ring traveller at a minimum value consonant with its imparting sufficient tension to the yarn to pull it from the roll. An increase in the degree of interlacing may compensate exactly for the decrease in twist resulting from the decrease in spindle speed.