Patent GB-1073182-A (GB)
Title: Improvements in or relating to bonded textile materials
Inventor: DAVIES STANLEY
IPC: D04H1/54
Filed: 1963-03-01
Abstract: A bonded fibrous material contains at least five per cent by weight of the total fibres of composite fibres.  These composite fibres comprise at least two fibre-forming synthetic polymeric components arranged in distinct zones across the cross-section of each fibre so that each component is continuous along the length of each fibre, and at least one, but not all, of the components is potentially adhesive and located so as to form at least a portion of the surface of each fibre.  The fibres are bonded together by the adhesive characteristics of the potentially adhesive component.  The term "fibre" includes filaments.  A potentially adhesive component is one that can be rendered adhesive without affecting any other components. Suitable fibre-forming polymers are: polyamides, polyesters, polyesteramides, polysulphonamides, polyolefines and polyurethanes. Both fibre-forming polymers may be of the same chemical class, in which case the fabric may be dyed uniformly with only one dyestuff. The fabric may be of non-woven, knitted, woven or plied structure. The components of the composite fibres may lie side by side, the potentially adhesive component may enclose the other component or the fibre may have a non-circular, e.g. a trilobal, cross-section.  The composite fibres may be present in the form of staple fibres including flock, continuous monofilaments or multifilaments or yarns in which the composite fibres are combined with fibres which are inert to the treatment taken to activate the potentially adhesive component.  Formation of non-woven webs may be by carding or garnetting together with cross-lapping if desired, by air laying on foraminous surfaces including shaped surfaces, e.g. for hat bodies, by direct random deposition of the continuous filaments in monofilament or yarn form on stationary or moving surfaces or by wet-laying techniques, as e.g. by the use of a Fourdrinier or other paper machine.  Activation of the potentially adhesive component may be by heating or by chemical treatment and is carried out with the web or fabric under pressure.  Chemical treatments referred to include the application of a hot non-aqueous, e.g. ethylene glycol, solution of formaldehyde or the application of nitric acid. Activation by heating may involve the use of heated platens, heated calender rolls or heated wire gauze sheets which impart a woven appearance to the surface of the fabric.  After formation and before activation, the web may be needled to consolidate it, or a light woven scrim fabric may be incorporated.  The composite fibres as spun may incorporate various additives such as plasticisers or soft resins, e.g. polyvinyl acetate, ester gum, coumarone resin or alkyd resin, to lower the softening point of the adhesive component; pigments, dyes, moth- or fire-proofing agents; fillers, abrasives and light stabilisers may also be included. Non-activatable fibres which may be present in the fabric include wool, silk, flax, cotton, regenerated cellulose, mineral fibres such as asbestos, rock wool and glass, and synthetic polymeric fibres such as polyamide or polyethylene terephthalate.  The non-woven fabrics of the invention range from paper-like and fabric-like materials to bulky felt-like materials or material resembling hard-board and are useful in heat, sound and electrical insulation, floor coverings, filters, dress fabrics, interlinings, and upholstery fabrics.  The woven scrim fabrics are particularly useful as reinforcing materials for plastics materials such as polyvinyl chloride.