GB816437A - Method for moulding reinforced plastic material - Google Patents

Abstract

816,437. Moulding resin-fibre articles. HUDSON ENGINEERING CORPORATION. Jan. 17, 1956 [Aug. 23, 1955], No. 1582/56. Class 87(2). An article, e.g. a hollow fan blade, is made by placing a layer 31 of reinforcing material, e.g. glass fibre, nylon, polyester or polytetrafluoroethylene on an outer translucent reinforced plastic mould section 20, placing a flexible core 29 having a device to partly expand the core on the layer 31, applying a further layer 32 of reinforcing material over the core, and folding the edges 31a of the layer 31 over the edges of the layer 32. Further outer mould sections 21, 22 are bolted to each other and to the section 20, and an epoxy or polyester resin is poured into the mould cavity, with the mould in a vertical position. The resin may be warmed and may contain a hardener or catalyst. A hollow shaft 34 is rotated to unwind canvas duck flaps 47, 48 about the shaft and thus cause the core 29 to partly expand and shape the reinforcement at the leading and trailing edges. Mercury or a bismuth-lead-tincadmium alloy is then filled into the core to expand it from the bottom upwardly and thus impregnate the reinforcing layers from the bottom upwardly. The mercury may be fed by a pump 43 from a supply 35 through a heat exchanger 38 to the hollow shaft 34. A valve 42 may be closed and a valve 41 opened and the mercury circulated in a closed circuit. Alternatively, the mercury may be heated by an immersion heater. For long articles, if the pressure due to the head of mercury is too great, the mould may be tilted. The temperature of the mercury may be such as to partly cure the resin near the closed end of the mould, whilst the impregnation continues towards the open end. Excess resin may escape through a pipe 44 or be absorbed in a wick 45. Metal inserts may be incorporated in the article.