Patent GB-594138-A (GB)
Title: Improvements in the manufacture of laminated fabrics
IPC: D06M17/02
Filed: 1944-12-11
Abstract: 594,138. Compound sheet materials. BONARD, C. G. [Representative of DREYFUS, H.]. Dec. 11, 1944, No. 24791. [Classes 42 (i) and 140] Flexible laminated materials containing one or more textile fabrics and in which the structure of a textile fabric is visible directly or through, for example, a layer of transparent foil, are made by bonding together under pressure a number of layers of material comprising one or more textile fabrics containing fibres of a thermoplastic organic polymer, the polymer being caused to soften to bond the layers by generating heat within it by means of an alternating electric field of high frequency. The thermoplastic organic polymer may be a cellulose ester or ether, either simple or mixed, e.g. cellulose acetate, propionate, or butyrate, acetate-propionate, acetate-butyrate, acetatelaurate, acetate-stearate or acetate-nitrate, ethyl, propyl, benzyl or ethyl hexyl cellulose, or ethyl cellulose acetate. Alternatively, thermoplastic synthetic resins may be used, e.g. polymers or interpolymers of vinyl chloride and vinyl acetate, polymerized paradichlorstyrene, and low-loss polymers such as polystyrene or polythene in conjunction with a plasticiser containing chlorine or a phosphate radical. The other polymers may also be plasticised, suitable plasticisers for cellulose acetate being dimethyl-, diethyl-, dimethoxyethyl- and diethoxyethyl-phthalate ; methyl- or ethyl - phthallyl - ethyl glycollate, butyl - phthallyl-butyl glycollate ; diethyl tartrate, triethyl citrate, acetyl triethyl citrate ; triphenyl-, tri-(monochlorethyl)-, tricresyl and tributyl-phosphate. The bonding can be effected in the entire absence of volatile solvents, potential solvents, or water. An outer layer or layers of woven or knitted fabric containing unplasticised thermoplastic fibres or non- thermoplastic textile fibres may be united to-a backing layer of fabric containing plasticised thermoplastic fibres. The backing or interlining fabric may be composed solely of fibres of the polymer, or may be woven or knitted from thermoplastic and non - thermoplastic yarns, or from yarns made from a mixture of non-thermoplastic fibres and thermoplastic staple fibres, or from yarns made by doubling or lapping together thermoplastic and non-thermoplastic yarns. The non-thermoplastic yarns present may be of natural or regenerated cellulose, or silk or wool. A thin foil of cellulose acetate may be bonded to one or both faces of a fabric containing both thermoplastic and non- thermoplastic fibres. The--bonding may be carried out in a press operated by compressed air and provided with polished metal plates adapted to act as the plates of an electrostatic condenser, with the fabric layers as dielectric, in a tunable circuit coupled to a high-frequency oscillator. The lower plate may be fixed and earthed, the upper one movable and insulated. Several fabric assemblies may be placed side by side on the lower plate ; or a multiplate press may be used, the top plate being insulated and connected to one side of the oscillator, the lowest plate earthed and connected to the other side of the oscillator, and the intermediate plates being insulated ; or the heating field may be established between a live intermediate plate and earthed upper and lower plates. When the outer fabric layers contain thermoplastic fibres, a pattern of local glazed areas may be produced, if the metal pressing members are covered over corresponding areas with heat-insulating non-conducting material which moderates the chilling effect of the metal. Specifications 462,011, 462,242, 557,369 and 580,045 are referred to.