Patent GB-987893-A (GB)
Title: A method of producing a non-woven fabric or leather imitation
IPC: D04H1/4334
Filed: 1962-05-08
Abstract: 987,893. Agglutinated fibrous fabrics. EHRNBERG & SONS LADERFABRIK A. B. May 8, 1962 [May 12, 1961], No. 17613/62. Heading D1R. [Also in Division B5] A non-woven textile fabric is produced by treating a fibre web from a carding machine with a binder, condensing the web in the plane thereof to form a layer of desired thickness, and subsequently causing the binder to bind the fibres of the layer to form a coherent sheet. Preferably, the binder is applied as a solution or suspension in volatile liquid, e.g. a plastisol or organosol. The web may be treated with a solution of a monomer and a common curing catalyst, polymerization taking place on heating or evaporation of the solvent. Impregnation may be carried out by passing the web through the binder solution or suspension, by passing the web over a roller dipping into the liquid or by spraying. Before heating or evaporation of the solvent the web is condensed by a combing machine, Figs. 3 and 4. Before impregnation the fibres may be coated with a blowing agent, e.g. diazo-amino-benzene dissolved in toluene or N -N<SP>1</SP> -dimethyl-N -N<SP>1</SP> -dinitroso-terephthal-amide dissolved in ethyl acetate, the decomposition temperature of the blowing agent being preferable immediately above the softening temperature of the binder. Aniline dyestuff may be added to the liquid containing either the binder or the blowing agent. To produce imitation leather having a grainlike surface one or more non-condensed webs treated with a binder only are placed on top of one or more condensed webs treated with a binder and a blowing agent of the laminate is cut into sheets and pressed between heated plates. The plate in contact with the non-condensed web may be provided with a "hair cell pattern". To produce imitation patent leather a condensed web is covered with a sheet of coloured p.v.c. foil and the laminate heated in a press. As shown in Fig. 1, a web 7 passes from a carding machine 8 on metal netting conveyers 9, 10 through a vessel A containing a blowing agent, through a drying chamber B and on conveyers 12, 13 through a vessel C containing impregnation liquid including the binder and which may also include a wetting agent, e.g. a phenol-cresol-alkyl  sulphonate, a plasticizer, e.g. dioctyl phthalate, a stabilizer, e.g. a complex barium-cadmium compound, and an accelerator. The web may be lightly squueezed between rollers. The web then passes through a combing machine D which condenses it to 2-20 the original thickness thereof and disorients the fibres. The condensed web 14 passes on a conveyer 15 through a drying chamber E and may be wound on a cylinder 16 or cut into sheets by a machine F, the sheets being pressed in a press G. The combing machine D, Figs. 3 and 4, comprises combs 18a, 18b, 18c, 18d, 18e, 18f, 18g, 18h extending transversely of the web, the combs 18a, 18c, 18e, 18g forming one group and the combs 18b, 18d, 18f, 18h forming a second group. Each comb is supported by slide couplings 19 in rods 20 movable in bearings 21 on a horizontal shaft 22. Cranks 24 provided on a shaft 23 are linked to the rods 20. The shafts 22, 23 are journalled in slides 25, 26 movable along guides 27, 28. At each side of the table a driving mechanism is situated and comprises a motor 29 to drive a shaft 31 through a clutch 30 connected and disconnected by a pneumatic cylinder 32. The shaft 31 drives the shafts 23 through a belt 33 and bevel gears 34, 35 and drives, through a belt 36, a crank-shaft 37 the cranks 38 of which are coupled to the slides 25 by links 39. Since as each comb is moved longitudinally of the table 17 it is also moved transversely thereof by the crank 38,the resultant movement is directed diagonally. The length of the stroke of each comb decreases towards the output end of the table 17. The combs of one group are moved whilst the combs of the other group remain stationary. The combs are partly pushed into each other at the ends of their strokes and thus become selfcleaning. The fibres may be nylon, rayon, wool or a mixture thereof. The binder may be natural or synthetic rubber latex, e.g. butadiene-acrylontrile latex, or a synthetic plastic, e.g. plasticized p.v.c. Examples stating percentages and weights of fibres and binders and also temperature and length of heating periods are given in the Specification.