| 摘要 |
1394084 Moulding tubes or rods SHAKESPEARE CO 21 June 1972 [22 June 1971] 29085/72 Heading B5A [Also in Divisions F2 E1] A tapered tube or rod is made by forming on a tapered mandrel 10 a layer of chopped fibres and resin 13, and overlaying with resin impregnated filaments 15 extending generally parallel to the axis of the tube or rod. (1) A steel mandrel 10 is polished, waxed and coated with a mould release compound. (2) The mandrel is positioned vertically or horizontally and sprayed with chopped glass fibres and resin 11 (or wrapped with an impregnated chopped glass fibre mat). (3) The layer is compacted by contoured rollers 14 and resin-impregnated glass fibre filaments 15 applied. (4) The filaments are wrapped with plastics filament tape 16 and heated to harden. (5) The tape 16 and mandrel 10 are removed. Alternatively, the mandrel 10 can be left in position, or replaced with a metal, fibre-reinforced plastics, or foamed plastics, core. The chopped layer 13 can be hardened and the mandrel 10 removed before applying the filaments 15. The mandrel 10 comprises differently tapered, or tapered and cylindrical sections. The thicknesses of the layers 13, 15 can be simultaneously varied along their lengths, e.g. to give a constant total thickness or the layer 13 is kept to a constant thickness, while layer 15 is varied inversely to the mandrel. The small end of the tube is closed to provide lighting standards, flag poles, powerline poles. Numerical examples are given. |
