GB971573A - Improvements in or relating to the manufacture of bulked yarns - Google Patents

Abstract

Bulked yarn comprising a crimped continuous filament core surrounded by a sheath of staple fibres is formed from two or more multifilament yarns, tows or bundles (at least one of which is thermoplastic) having different extensions to break. The yarns &c. in combination are simultaneously false-twisted e.g. by the process described in Specification 890,053, and drawn e.g. around a heated snubbing pin, whilst in heated condition, sufficiently to break one yarn &c. into staple length e.g. 8 inch, fibres which form the sheath around unbroken filaments, which have been crimped by the false-twisting and heating and thereby form the core with the ends of the fibres entangled therein. The bulked yarn may be modified by heating under a controlled tension to remove the crimp from the core and enhance the crimp in the sheath fibres. The yarns &c. may be of the same or different materials e.g. polyamides, polyesters, polyhydrocarbons, or regenerated cellulose. The different extensions to break may be produced by additives e.g. alkathene, in the melt to weaken some filaments, by spinning under conditions which yield denier variation or different spun orientation, by subjecting the filaments to random quenching after spinning e.g. by spraying water thereon whilst they are in the conditioner tube so that a highly spherulitic yarn is obtained, by random fusion of filaments, physically or chemically damaging the yarn e.g. by abrading, or by fully drawing one yarn (or drawing the yarns to different extents) prior to combining, false-twisting &c. with the other(s). The bulked or the modified yarn may constitute the weft with conventional nylon warp yarns in plain or sateen weave fabrics.