Patent GB-1085097-A (GB)
Title: Composite material
Inventor: GOY RONALD STANSFIELD
IPC: D04H3/10
Filed: 1964-06-13
Abstract: A composite material is made by assembling a layer of extended continuous synthetic crimped textile fibres in substantially aligned relationship, relaxing the fibres into a crimped condition, assembling this layer with a layer of staple textile fibres and needling the layers together by barbed needles. Preferably the material contains up to 90% by weight of staple textile fibres.  More than one continuous fibre layer may be assembled with more than one staple fibre layer and a sandwich structure may be built up. Preferably, during the needling operation, the needles pass substantially through the assembly. Needling can be effected from either side of the assembly but, preferably, the assembly is first needled from the surface comprising the continuous fibres and subsequently from the surface comprising the staple textile fibres. Preferably, the assembly receives from 1,500 to 5,000 needle punches per square inch.  Preferably, the continuous fibres are crimped and assembled under tension into a sheet and the tension is subsequently removed to allow the continuous fibres to relaxe into a crimped condition. Alternatively, the continuous fibres in non-crimped condition can be drawn from a beam to form a sheet and crimped in any convenient manner in this form.  The sheet is subsequently relaxed. Thermoplastic fibres may be crimped by (a) a false twisting technique, (b) a stuffer box treatment, (c) edge crimping, or (d) passing between fluted rollers.  Non-thermoplastic fibres may be crimped by cross-linking or steam setting.  Alternatively, continuous fibres having a potential crimp may be assembled into a sheet and the crimp developed.  For example, fibres spun from two polymers by a conjugate jet or rayon having an unbalanced skin structure can be crimped by wetting.  Continuous nylon fibres can be assembled whilst wetted with a swelling medium and crimped by drying off the wetting medium.  The staple fibres may be natural or synthetic fibres, e.g. wool, jute, cotton, viscose rayon, acrylic, polyethylene terephthalate, polyamide or polypropylene fibres.  Mixtures of staple fibres may be used.  The continuous fibre layer may be applied to the staple fibre layer as it is carried from a carding machine to the needling head.  Alternatively, the staple fibre layer is applied to the continuous fibre layer as it is carried from the relaxation zone of the machine to the needling head.  The staple fibre layer may be cross-lapped onto a carriage moving at right angels thereto and then the continuous fibre layer is applied, optionally by cross lapping, to the upper surface thereof.  The layers may be cross-lapped together onto a moving carriage.  Subsequent to needling, the material may be milled, bleached and stenter-dried.  The surfaces of the material may be raised on a conventional machine.  The material may be used as a tennis ball covering, a wadding or packing, a cover for cushions, an upholstery material or in the manufacture of carpets.  In the latter case, a carpet backing material of a jute hessian is attached to the material by a latex adhesive.