Patent GB-1205281-A (GB)
Title: A method for manufacturing synthetic multicore composite filaments and fabrics made therewith
IPC: B60C9/00
Filed: 1968-03-13
Abstract: 1,205,281. Making synthetic muiticore composite filaments. TORAY INDUSTRIES Inc. 13 March, 1968 [16 March, 1967; 11 May, 1967; 16 Aug., 1967; 21 Oct., 1967; 26 Oct., 1967; 11 Nov., 1967]. No. 12237/68. Heading B5B. [Also in Division B7] Synthetic bonded filaments of a multicore cross-sectional profile are made from synthetic organic thermoplastic polymeric material having different melting points by forming a bicomponent filament of the sheath-core type wherein one of the synthetic materials having a higher melting point than the other forms a core and another of the synthetic materials forms the sheath, assembling a number of the filaments in the form of a single multifilament bundle, and heating the bundle at a temperature between the melting points of the synthetic materials, whereby the sheaths of the individual bicomponent filaments are melted and individual bicomponent filaments become bonded together to form a single multicore composite filament wherein the cores are embedded or encapsulated in a common matrix. The multicore filaments may be made by forming homofilaments from the synthetic materials having different melting points, assembling a number of the homofilaments in the form of a single multifilament bundle and heating said multifilament bundle at a temperature which is higher than at least one of said melting points of said synthetic materials and lower than at least another one of said melting points whereby the matrix-forming filaments are melted and the core-forming filaments become bonded together to form the multicore composite filaments. Twists may be imparted into the assembled multifilament bundle prior to the heating operation whereby the single multicore composite filament formed is provided with a number of air cells of various dimension randomly distributed throughout the matrix. The material of both the cores and the matrix may be selected from the group of polymers composed of polycaprolactam, polyhexamethylene adipamide, polyethylene terephthalate, polypropylene, polyethylene, polyacetal, polyvinyl chloride, polystyrene and ordinary and block copolymers of these polymers; also blends of the polymers. The core portions of the multicore composite filament may be polyhexamethylene adipamide in combination with polycaprolactam as the matrix. Alternatively the core portions may consist of polyethylene terephthalate and the matrix may consist of polycaprolactam. Both the core and matrix components of the multicore filaments may consist of two different polyamides. The core polyamide may have a melting point at least 15‹ C. higher than the matrix polyamide. The core and matrix may consist of nylon 66 and nylon 6 respectively and the two different nylons may differ from one another in their degree of polymerization. The composite multicore filaments of the invention may be woven to form a fabric suitable for use as a chafer strip for tubeless tyres. Alternatively the fabric may be woven from the yarns or bundles of filaments destined to form multicore filaments and the fabric heated to a temperature between the core and matrix components to convert the fabric yarns into multicore bonded filaments. The heating of the fabric may be effected by vulcanizing the tyre after the unheated fabric has been used in its construction.