GB1105596A - Improvements relating to multifilament yarns - Google Patents

Abstract

A coalesced multifilament yarn comprises groups of filaments coalesced together, the average force required to separate the individual filaments from one another being at least 45 milligrams, the groups also being coalesced together, the average force required to separate the groups from one another being between 20 and 50 milligrams and not more than two thirds of the average force required to separate the filaments. In one example spandex filaments are dry spun and then are passed in groups through a plurality of false-twist gas jets, with the twist running back in each group of filaments to a point in the spining cell where the filaments are sufficiently tacky to form the required degree of cohesion. The groups are then forwarded to a guide or further false-twist gas jet where the groups coalesce together, and then in turn to a first feed roll, lubricant applicator, second feed roll and winding apparatus. The yarn may be stretched or relaxed between the feed rolls. In a modification the spinning orifices are arranged in spaced groups and there is only one false-twist jet, the twist within a group of filaments, running back into the cell, but the twist between the groups of filaments not running back so far. The degree of cohesion within a group may vary from group to group. In other modifications the filaments may be wet spun, the groups of filaments may be coalesced together by treatment with a plasticizer or solvent by means of a wick, bath or roller, with the groups being brought together by a guide or slot, or the filaments may be of nylon, acrylonitrile polymers or cellulose acetate. A spandex yarn may be knitted, or laid in to a knitted fabric, and during the fabrication process the groups of filaments partially separated from one another.