Patent GB-548177-A (GB)
Title: Improvements in the manufacture of stiffened fibrous materials and articles composed thereof
IPC: D06Q1/08
Filed: 1941-03-14
Abstract: 548,177. Stiffening textiles, paper, leather, &c. FRANKFURTHER, P. March 14, 1941, No. 3512. [Class 15 (ii)] [Also in Group VIII] A non-uniform stiffness is imparted to fibrous materials or articles made of such materials by immersing the articles in a liquor containing a thermoplastic resinous polymerization product and locally precluding or eliminating the stiffening agent or locally diminishing or increasing its stiffening action. Fibrous materials of all kinds may be treated, e.g. textiles, leather, artificial leather, paper, or cardboard. Wholly or partly finished articles may be treated. The process may be applied in the production of boots, shoes, leather handbags, bandages or other surgical, orthopaedic, and pharmaceutical articles ; book bindings ; maps, charts, plans, drawings and the like which are to be stiffened by a varnish for protective purposes and are to remain soft in the regions of the fold-lines ; collars, cuffs and other wearing apparel where, e.g. the regions of fold-lines, stad holes, or points of turned-down collars are to be less stiff; stiffened inter-linings for coat collars and reveres. The polymerization product may be a polyvinyl acetate or other ester, polystyrene, or a polyacrylic ester. It may be used in the form of a solution in a volatile solvent. A substance having a softening action on the stiffening agent may be applied to those parts which are to remain soft, before the immersion, or the softening agent may be applied locally after the immersion in the stiffening agent. The subsequent application of softener may be made while the impregnated materials are hot, e.g. while laid on a heated plate or on a wire netting or asbestos sheet placed over a heated plate. To prevent running of the softening agent, it may be thickened, e.g. with a solution of an artificial resin. Diphenyl, benzyl benzoate, dibutyl phthalate, triacetin, or quinone are suitable softeners for .polyvinyl acetate. The softener may be diluted with acetone or alcohol. Non-uniform stiffening may be obtained by local application of an agent which hardens the stiffening agent, this treatment being effected before' or after immersion in the' stiffening agent. Tannic acid or formaldehyde may be used as hardening agent for the stiffener. Local application of softening agent or hardening agent may be effected by brushing, spraying, printing, or dropping. Before immersion in the stiffening liquor, a wax such as beeswax, or paraffin wax, or other resist may be applied locally to the fibrous materials. This is removed, subsequently, e.g. by melting and washing with boiling water. Non-uniform stiffening may be obtained by squeezing out the stiffening liquor, immediately after the immersion, from the areas which are to be less stiff. Plain or embossed pressure rollers may be used. Another method is to secure the material between a pair of stencil plates and then immerse in the stiffening liquid. The impregnated material may be heated locally, e.g. by hot rollers or plates and intervening stencils, and then cooled, so as to obtain non-uniform stiffening.