Patent GB-817875-A (GB)
Title: Improvements in or relating to a process and equipment for the production of parts from fibre-reinforced synthetic resins
IPC: B29C41/36
Filed: 1956-09-26
Abstract: <PICT:0817875/III/1> A process for the production of parts from fibre-reinforced synthetic materials is characterized in that liquid and sprayable cold or thermosetting synthetic binding media, for example polyester resins, ethoxyline resins, silicone resins and phenol resins and, at the same time, cut fibres, for example fibrous materials obtained from mineral melts or chemically produced, as well as, if desired, mineral and/or vegetable filling ingredients are fed to the gum of a spraying installation, intimately mixed so that the cut fibres are enveloped by the binding medium and thereafter sprayed on to or into moulds or other surfaces. Specified fibres are glass, basalt, nylon, perlon and thin metallic threads.  Specified fillers are quartz, asbestos fibres, cotton linters, powdered cork, wood dust and chalk.  In a spraying gun as shown in Fig. 1, a fibre strand 1 is guided by rollers 2 and 3 to a roller 4 fitted with cutting blades. A strong jet of resin and compressed air pass through nozzle 7 and sucks cut fibres from cutter 4 into chamber 8 wherein they are intimately mixed with the resin.  An example describes the production of a boat hull by spraying fibre-reinforced synthetic material into a hollow mould.  In a modified form of apparatus (Fig. 3, not shown), a separate fibre-cutting mechanism is movably mounted on rollers on a guide rail, which itself forms a carriage on a pair of guideways extending at right angles to the rail, and is connected to the spray gun by a flexible conduit.  In a further modification (Fig. 4, not shown), a spraying gun is provided with two nozzles conveying at right angles to one another, and a resin mixed with a catalyst, with or without pigments, is fed to one, and a resin cotaining setting or accelerating agents to the other. In an example, a mould for a boat hull is provided with a parting coat of polyvinyl alcohol, and is then sprayed with a mixture of polyester resin compositions, one of which contains dimethylaniline as accelerating agent and the other benzoyl peroxide as catalyst, together with chalk, silica and pigment. Further coats of these compositions are subsequently applied, together with glass fibres, and evened out by a manually applied roller.  Specification 577,534, [Group VIII], is referred to.ALSO:A process for the production of parts from fibre-reinforced synthetic materials is characterized in that liquid and sprayable cold or thermosetting synthetic binding media, for example polyesters, ethoxyline, silicone and phenol resins and at the same time cut fibres, for example fibrous materials obtained from mineral melts or chemically produced, as well as, if desired, mineral and/or vegetable filling ingredients are fed to the gun of a spraying installation, intimately mixed so that the cut fibres are enveloped by the binding medium and thereafter sprayed on to or into moulds or other surfaces.  Suitable forms of spray guns are described. Specified fibres are glass, basalt, nylon, perlon and thin metallic threads.  Specified fillers are quartz, asbestos fibres, cotton linters, powdered cork, wood dust and chalk.  An example describes the production of a boat hull by spraying fibre-reinforced synthetic material into a hollow mould. A mould-release film of polyvinyl alcohol was first applied to the interior of the mould and then a layer of synthetic resin was sprayed thereon, the resin comprising polyester resin, chalk, pigment, dimethylaniline, benzoyl peroxide and silica.  After partial polymerization of this resin layer had been allowed to take place a further thick layer was sprayed comprising the same resin mixture as above together with cut glass fibres.  This layer was evened out by means of a manually applied roller and then two further layers of the same resin-fibre mixture were applied. Thereafter complete polymerization of the resin in all the layers is effected.  Specification 577,534 is referred to.