Patent GB-908753-A (GB)
Title: Method and apparatus for forming fibre reinforced resin articles
IPC: B29C70/08
Filed: 1961-01-16
Abstract: 908,753. Laminates; coating apparatus. UNIVERSAL MOULDED FIBER GLASS CORPORATION. Jan. 16, 1961 [Jan. 15, 1960], No. 1739/61. Class 140. [Also in Group V] A method of forming continuous lengths of articles composed of fibre reinforced resin materials comprises impregnating the fibre reinforcement with an excess of a heat-hardenable liquid resin material by feeding continuous lengths of the fibre reinforcement through a supply reservoir of the liquid resin material, expelling the excess resin material by feeding the impregnated fibre reinforcement into the entrance end portion of a confining passage, returning the expelled excess resin material to the supply reservoir, maintaining the entrance end portion of said passage at a temperature sufficiently low to substantially preclude hardening of the liquid resin material being expelled and returned to the reservoir, and after expulsion of the excess resin, feeding the fibre reinforcement with the remaining resin through a further length of confining passage of substantially uniform cross-section and maintaining the temperature in said further length sufficiently high to effect hardening of the resin therein and solidification of the formed article in said portion of the confining passage of uniform cross-section and pulling on the solidified article beyond the exit end of the confining passage to feed the materials and article through the confining passage. As shown (Fig. 1), woven fibreglass strips F from supply rolls 7 are fed over guide 8 and thence into reservoir 9 containing heat-hardenable resin 10, e.g. a polyester resin, in liquid state, wherein the strips pass over guides 11 and are then drawn into the entrance end of the forming device, which may be shaped to impart a desired shape to the article, having upper and lower portions 12 and 13, which provide a confining channel with an enlarged inlet 14 and having a main portion of substantially uniform cross-section. Beyond the forming device a plurality of driven friction rolls 15 draw the strips from the supply rolls, through the impregnating bath and through the confining channel. For some purposes all of the fibrous material may be impregnated prior to entry into the forming device, while for other purposes it is desirable to feed to the forming device a part of the fibrous material in unimpregnated condition. In the embodiment as shown, strips of fibrous material 32 and 33 are fed unimpregnated to the top and bottom surfaces of the assembly of impregnated strips F. The fibrous material may consist of woven strip or unwoven mat or a multiplicity of threads or rovings and metal pieces and wood strips may be included in the fibres. To harden the resin during passage through the forming device the latter is heated as by circulation of a heat transfer medium through channels 26 (Fig. 5) having inlet 27 and outlet 28. To prevent heat from the heated portion of the forming device being conducted to the entrance end and causing premature curing of the resin with ensuing jamming of the fabric, the entrance portion may be cooled by circulation of water through channels 29 (Fig. 5) having inlet 30 and outlet 31.