GB1316434A - Conjugate filaments - Google Patents

Abstract

1316434 Conjugate filaments IMPERIAL CHEMICAL INDUSTRIES Ltd 30 June 1970 [2 July 1969] 33358/69 Heading B5B A conjugate filament comprises a polyester, suitably polyethylene terephthalate, and a polyamide, suitably polyhexamethylene adipamide on a copolymer, preferably in an 80/20 w./w. ratio, of polyhexamethylene adipamide and polyhexamethylene terephthalamide, in an essentially sheath/core relationship wherein the polyamide, which suitably comprises 35-65% by weight of the filament, forms the core 1 and protrudes through the polyester sheath 2 at at least one point in a cross-section thereof to form one or more portions of the surface of the filament, the percentage of the surface area of the filament over which the polyamide core forms the surface being in the range 1-25%, preferably 3-11%. The core may protrude through the polyester sheath at only one point in the filament cross-section (as in Fig. 1) in which case the filament is self-crimping in so far as it forms tight helical crimps when relaxed in steam or hot water after being fully drawn. The conjugate filaments may be produced by a process involving the use of the spinneret assembly of British Specification 1,100,430 with the spinneret plate of Fig. 2 in which the protrusions 7 extend upwards from the spinneret plate 4 to the baffle plate of that spinning assembly and serve to restrict the flow to the orifices 5 of the superposed layers of polymer melts confined in the space above the plate 4 in one or more areas adjacent said orifices. Examples relate to the spinning of conjugate eccentric sheath/core filaments in which the sheath is formed from polyethylene terephthalate and the core is formed from a copolymer (80/20) of polyhexamethylene adipamide and polyhexamethylene terephthalamide. Filaments produced according to the invention have the warmth of handle of conventional polyester filaments and some of the dyeability characteristics of polyamide filaments.