| 摘要 |
1,259,084. Bonded non-woven fabrics. COMPAGNIE DE SAINT-GOBAIN. 2 Feb., 1970 [5 Feb., 1969], No. 4835/70. Heading D1R. Composite mats, farbics, &c. are produced by forwarding a fibrous layer 1 through a preheating oven 4 to an electrostatic chamber 9. Measured quantities of powdered resin are introduced into the chamber by distributor 16. The chamber 9 contains a porous plate 10 with metal points 13 connected to one pole of an electric generator 12. The fibres are given an electrostatic charge of one polarity and the resin particles an electrostatic charge of opposite polarity in this chamber so that they are attracted to each other. The impregnated fibrous layer 1 proceeds to an oven 17 where the resin is melted through calender rollers 21 which are cooled and cooling tunnel 22. The sheet may then be rolled up or out into panels and stacked. This apparatus gives preferential deposition of resin on the bottom surface of layer 1. For equal deposition of resin on both surfaces the layer 1 may be led vertically through the electrostatic chamber 9. Examples of fibres forming the mat are glass, quartz, silica, asbestos, carbon, graphite or boron fibres. The resins may be thermoplastic, e.g. polystyrene, copolymers of styrene and acrylonitrile or butadiene, polyethylene, polypropylene and copolymers of propylene and ethylene, polyvinyl chloride and copolymers thereof, methyl polymethacrylate, copolymers of methacrylic or acrylic acid esters polyamides, poly lactams, e.g. polycaprolactam, hexamethylene diamine, polycarbonates, polyphenylene oxide and cellulose derivatives, e.g. cellulose acetate. Examples of thermo-setting resins are aminoplasts, phenoplasts, epoxides and alkyds. |
