Patent GB-728865-A (GB)
Title: Fabrics composed of adhesively-bonded fibres and process for producing such fabrics
Inventor: NOTTEBOHN CARL LUDWIG
IPC: D04H1/68
Filed: 1953-03-17
Abstract: 728,865. Fabrics composed of agglutinated fibres; coating webs. FREUDENBERG KOMM.-GES., C. March 17, 1953, No. 7414/53. Class 140. A loose fleece made of superposed webs of fine cardable fibres is coated on one or both sides with an adhesive to give a light surface cohesion without appreciably reducing porosity, is then impregnated through one or both surfaces with a foamed, aqueous binder, and is dried without pressure. The binder is precipitated as filmy particles which cement the fibres at their crossing points leaving relatively large interstices in the form of flat pores. As shown, 4 thin webs 11-14 of fine cardable fibres arranged in random directions are superposed to form a fleece with adjacent webs disposed, if desired, at an angle to each other. The fleece is passed between heated rollers 15, 16 and is simultaneously slightly stretched lengthwise. Foamed rubber latex prepared in a trough 18 is pushed by blades 19 on an endless belt 20 over the edge of the trough, falls on to the fleece, and is spread by a blade 21. The coated fleece is drawn through chamber 22, where it is dried, around roller 23, and between rollers 24 and 25, where latex foam supplied to the nip of the rollers is pressed into the fleece so as to penetrate completely through it. The fleece is again dried while passing around rollers 26 and 27 in chamber 22 and is finally wound up into a roll 29. The fleece is further stretched during impregnation and drying. The fleece may be further vulcanized without pressure, calendered, washed to remove wetting agents and other water-soluble materials, impregnated with an aqueous emulsion of paraffin, dried, and further treated to ensure complete vulcanization. Suitable fibres are cotton, ramie, flax, hemp, jute, wool, goat, camel, or human hair, viscose or cellulose acetate rayon, alginate fibres, protein fibres, glass or asbestos wool, polyvinyl or polyvinylidene fibres, polyacrylonitrile, or nylon. The binder may be a natural or synthetic, vulcanizable or pre-vulcanized, rubber latex which may contain vulcanizing agents and accelerators, foam-stabilizing agents and anti-oxidants, g lycerine, clay, chalk, silica, wax, paraffin, or starch. Alternatively the binder may be a foamed dispersion of a thermoplastic resin such as a polyvinyl ester, e.g. the chloride, a polyacrylic ester, e.g. polymethyl methacrylate, polystyrene, or a polyvinylidene ester. In examples (1) 6 webs consisting of intermingled wool, human hair, camel hair, cotton, and viscose rayon fibres are superposed and formed into a fleece by passing between heated rollers ; the fleece is coated with a foam of a dilute dispersion of adhesive to give a light surface cohesion, and is then completely impregnated with a foamed concentrated dispersion, the dispersed composition containing in each case a butadiene-styrene polymer, sodium isobutylene naphthalene sulphonate, zinc oxide, zinc dimethyl dithiocarbamate, sulphur and phenyl alpha naphthylamine; (2) the impregnated material of example (1), after washing and drying, is impregnated with a paraffin emulsion containing aluminium triformate; (3) wool, wool comber waste, and torn cotton fibres are mixed and made into loose webs of which 6 are superposed to form a fleece; the surface of the fleece is lightly coated with a foam made from a diluted natural rubber latex composition, impregnated with a foam of a more concentrated butadiene-styrene copolymer dispersion, vulcanized, and, if desired, impregnated as in example (2); (4) 3 webs containing a mixture of cotton, ramie, and viscose rayon fibres are made into a fleece which is given surface cohesion by coating with a foamed polyvinyl chloride emulsion, and impregnated with a mixed dispersion of polyvinyl chloride and polymethyl methacrylate; (5) 30 webs of a wool cellulose acetate fibre mixture are superposed and formed into a fleece which is coated with a foam of a dilute dispersion containing butadiene-acrylonitrile and butadiene-styrene polymers, and then impregnated with a concentrated foam containing the same polymers ; (6) 2 webs of a fibre mixture containing wool, viscose rayon, and nylon are combined into a fleece which is coated on both surfaces with a natural latex foam, and then impregnated by pressing the same foam through both surfaces; (7) 8 webs of cellulose acetate fibres are made into a fleece which is lightly coated with a foamed butadieneacrylonitrile polymer dispersion and impregnated with a foamed chloroprene latex composition containing a paraffin emulsion ; (8) 6 webs of a fibre mixture containing wool, cotton, viscose rayon, and nylon are made into a fleece which is coated with a foamed butadiene-styrene latex and impregnated with a foamed aqueous dispersion containing butadiene-styrene polymer, polyvinylidene chloride, polyvinyl acetate, and vulcanizing ingredients; (9) a fleece made by compressing and slightly stretching 20 superposed webs containing synthetic protein and cotton fibres is coated and then impregnated with foamed dispersions of a butadiene-acrylonitrile polymer composition; (10) a fleece made from 12 webs of a fibre mixture containing viscose rayon, ramie, and polyacrylonitrile fibres is coated with a foamed aqueous dispersion of polyacrylonitrile, and then impregnated on the untreated side with a foamed polystyrene dispersion pigmented with titanium dioxide. The products are suitable for linings or stiffenings for garments.