Patent GB-621950-A (GB)
Title: Laminated products and methods of making them
IPC: D04H13/00
Filed: 1945-07-18
Abstract: 621,950. Compound sheet materials; agglutinated fibrous materials; coated fabrics. RAYNER, G. F. (Sylvania Industrial Corporation). July 18, 1945, No. 18389. [A Specification was laid open to inspection under Sect. 91 of the Acts, Jan. 21, 1946.] [Class 140] A felt-like laminated material suitable for heat- or sound-insulation, upholstery, and shoe stiffeners, is made by commingling potentially adhesive, thermoplastic fibres and non-adhesive fibres, forming a layer of the mixed fibres on at least one surface of a layer of fabric by depositing the fibres from a suspension in air, and heating to render the thermoplastic fibres tacky so that they bind the fibres together and unite the layers. The thermoplastic fibres may be formed, as by spraying, simultaneously with the commingling of the two kinds of fibre. To assist union of the layers, the fabric may contain thermoplastic fibres, or a thin layer consisting solely of such fibres, or a thin, continuous film, which may be applied as a coating or impregnation, may be interposed between the mixed fibrous layer and the fabric. Heating may be by hot air, steam, or high-frequency electric field. The fabric may comprise thermoplastic fibres, non-thermoplastic fibres, or both types, associated by weaving, knitting, netting, lacing, braiding, or crocheting. Two fabrics may be disposed between three fibrous webs or bats. The thermoplastic fibres may be cellulose ethers or esters such as the acetate, acetate-propionate, or acetate-butyrate, ethyl or benzyl cellulose, synthetic resins, either thermoplastic or thermosetting but in the thermoplastic state, e.g. coumarone or indene resins, polyvinyl resins such as polystyrene, or copolymers of a vinyl halide and vinyl acetate, vinyl cyanide, or an acrylic acid derivative, acrylic or methacrylic resins, phenol-, urea, or sulphonamide-aldehyde resins, alkyd resins, sulphur-olefine resins, polyamide resins, synthetic rubbers, mixtures of one or more of these materials, or the fibres may be made from rubber, guttapercha, or balata. The non-adhesive fibres .may be wood-pulp fibres, cotton, flax, jute, kapok, silk, regenerated cellulose, cellulose esters and ethers, cellulose thiourethanes, natural or synthetic rubber, spun glass, asbestos, mineral wool, natural or synthetic resins. The fibres may be made by slitting, cutting, or shredding films, by cutting continuous filaments into short lengths, by dispersing liquid fibre-forming material, e.g. by spraying, into a liquid or gas, or may be waste fibrous material such as cotton linters, flock removed from fabrics during shearing operations, leather dust, short fluffy waste thrown out of carding or combing machines, wool waste, the waste from slubbing, roving, and wool tops. A fabric 2 unwound from a roller 2a is carried on an endless, flexible, perforated belt 3, through chambers 4 and 9 in which dispersed fibres are allowed to settle on the fabric, and the resultant product 19 subjected to heat with or without pressure. In chamber 4, potentially adhesive fibres are formed and simultaneously dispersed by spraying a composition from nozzles 6, solvent and material not formed into fibres being removed by vent 8 and tray 7. Potentially adhesive fibres similarly formed in a chamber 10 are blown by means of a blower 15 into chamber 9 where they mingle with non- adhesive fibres fed in by blower 17. Air escapes from chamber 9 through a screened exhaustpipe 18. The product 19, while held between foraminous travelling belts 3 and 20, is first heated by hot air circulated through it by blower 26 and exhaust pump 27, and then cooled by air circulated through it by blowers 30, 32. Rolls 28 and 29 may apply pressure. Alternatively, a mixture of thermoplastic and non-adhesive fibres may be deposited on a foraminous belt, a fabric laid thereon, and a further layer of mixed fibres deposited on top of the fabric. The Specification as open to inspection under Sect. 91 comprises also the formation of the felt-like layer by needling the layer on to the fabric, by napping a fabric woven from voluminous yarns, or by carding; the fibres may be rendered tacky by solvents or swelling agents. This subject-matter does not appear in the Specification as accepted.