GB805309A - Improvements in and relating to composite fabrics - Google Patents

Abstract

805,309. Composite fabrics; knitted fabrics. COURTAULDS, Ltd. Feb. 27, 1957 [Feb. 29, 1956], No. 6292/56. Classes 74 (2) and 140. [Also in Group IX] A composite fabric for use as cloth or apparel for protection of objects and persons against acid or alkali comprises outer layers of fabric woven or knitted essentially from polyacrylonitrile or polythene threads and an interlayer of loose staple fibres resistant to acid or alkali or both, the layers being secured together, by stitching or thermal bonds spaced at least 0.5 inch apart, so as to preserve the vapour permeability of the fabric. The interlayer fibres are preferably of polythene, polystyrene or polyacrylonitrile. Instead of polyacrylonitrile threads and fibres copolymers containing not less than 80 per cent of acrylonitrile may be used, for example a copolymer containing 93 per cent of acrylonitrile and 7 per cent methyl acrylate. The securing means may comprise rows of stitches of acid or alkali-resistant thread such as polythene spaced about one inch apart across the fabric, or the fabric may be heat pressed along similarly spaced lines or heat bonded in random spots. In an example, upper and lower 3/1 twill fabrics of polythene yarns, heat stabilized at 65-70‹ C. and comprising respectively 156 warp and 58 weft threads per inch of 0.005 inch yarn and 124 warp and 49 weft threads per inch of 0.0075 inch yarn, enclose a loose web of fibres of polythene or the copolymer mentioned above about 0.015 inch thick and weighing about 3¥oz. per square yard, the fibres varying in length and diameter but having a mean diameter of 4-5 microns. The assembly is secured by rows of polythene stitches about one inch apart across the fabric. Specification 471,590, [Group IV], is referred to.