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Process for manufacturing a composite panel for shock absorption
The moulded article is cooled, removed from the mould and welded to a second thermoplastic article. The welded product is then exposed to cross-linking conditions so as to convert a portion of the article to a thermosetting material. Process for deep drawing composite thermoplastic foil with a PVDC layer Reifenh~iuser, H. (Reifenh~iuser GmbH & Co, Maschinenfabrik, Troisdorf, FRG) US Pat 4 877 571 (31 October 1989) The process consists of heating a composite thermoplastic foil with a PVDC layer to a temperature above the crystallization temperature of the pVDC layer ( > 130°C) so that the degree of crystallization of the layer is reduced by at least 50%. The foil is then immediately quenched to below 50°C and then deep drawn in a time interval of 15 to 300 seconds. Method and apparatus for constructing circumferentially wrapped prestressed structures utilising a membrane Dykmans, M.J. (El Cajon, CA, USA) US Pat 4 879 859 (14 November 1989) A process is described for forming a domed structure with composite walls on a base. An inner membrane is placed on the base and inflated. Wall forms are placed adjacent to and inside the membrane. These wall forms are radially supported by at least one truss assembly and a fibre-reinforced plastic material is placed outside the membrane. This is prestressed by circumferentially wrapping wire round it (the wire has a compressibility less than that of the wall forms). Additional alternating layers of fibrereinforced plastic and wire prestressing are applied. Finally, the wall forms and truss are removed and the membrane deflated. Fibre reinforced thermoplastic resin matrix composites Jones, R.J. and Chang, G.E.C. (TRW Inc, Redondo Beach, CA, USA) US Pat 4 880 584 (14 November 1989) A fibre-reinforced composite is made by
forming a prepreg lay-up of a stack of plies consisting of 10-50 wt% thermoplastic polyimide resin and 90-50 wt% continuous reinforcing fibres. This is compression moulded by applying progressively increased pressure and temperature in stages; cooling whilst maintaining the pressure and then heating the resulting lay-up under ambient pressure to at least 370°C. Method of explosively forming a multilayered composite material Gupta, S.K. and Pinder, J.T. (Rolls Royce, Inc, Greenwich, CT, USA) US Pat 4 881 314 (21 November 1989) A method of making a fibre-reinforced metal-matrix composite is given. A green compact of powdered metal particles bonded together with a suitable binder is placed against an anvil. At least one layer of fibres is placed on this layer, a second powdered metal layer is laid on the fibre layer and an explosive charge is laid against this. The explosive is detonated to join the layers together and the resultant structure is sintered at a temperature below the reaction temperature of the metal and the fibres. Process for manufacturing a composite panel for shock absorption Ando, Y., Ishige, Y., Kinugasa, T. and Sato, S. (Honda Giken Kabushiki Kaisha, Tokyo, Japan) US Pat 4 882 002 (21 November 1989) The process comprises applying to a surface of a polyolefin member a polyester hotmelting bonding agent which is hardened by adding an isocyanate cross-linking agent. A cross-linking type, hot-melting bonding agent is applied to one surface of a laminating member and the two treated surfaces are placed in contact and bonded together by the application of pressure. Method of producing a reinforced rubber hose by using a plastic mandrel Ohkita, K., Ogata, K. and Niwa, K. (Tokai Rubber Industries Ltd, Aichi, Japan) US Pat 4 882 101 (21 November 1989) A long plastic mandrel is extruded, an unvul-
canized inner rube tube is extruded onto this mandrel and a reinforcing layer is then formed on the outer surface of the tube. An outer unvulcanized tube is extruded around this and the whole is vulcanized. The long hose and contained mandrel are then cut into suitable lengths and the mandrel removed. The pieces of mandrel are crushed and recycled through the extruder. Moulding of fibre reinforced plastic articles Radvan, B. and Willis, A.J. (Wiggins Teape Group Limited, Basingstoke, UK) US Pat 4 882 114 (21 November 1989) A foamed aqueous dispersion is formed from 20-60 wt% single, discrete fibres 7-50 mm long with a Young's modulus > 10 GPa and 40-80 wt% of an unconsolidated particulate plastic selected from the group consisting of a thermoplastic and a thermosetting material with a particle size < 1.5 mm. This is laid down and drained on a forminous support to form a web which is transferred to an oven where it is heated first to remove residual moisture and then to bond the fibrous and plastic components together in such a fashion that the particulate form of the plastic is substantially maintained. The resultant sheet is passed through heated air to a temperature at which the viscosity of the thermoplastic component is sufficiently low to permit moulding; the sheet is then transferred to a compression mould and subjected to a predetermined pressure to produce the shaped composite article. Improved production of carbon fibres Beneke, H. and Peter, S. (Rutgerswerke AG, FRG) US Pat 4 882 139 (21 November 1989) Purified and polymerized concentrated carbon fibre precursor is formed by dissolving a supercritical gas in mesophase pitch at a pressure of 1-3.5 × 107 Pa at a temperature up to 150 K below the melting point of the mesophase pitch to form a low viscosity melt. This is separated into an isotropic phase and an anisotropic carbon fibre precursor that is spun at temperature into fibres which are oxidized, carbonized and optionally graphitized.
COMPOSITES. MAY 1991
257
forming a prepreg lay-up of a stack of plies consisting of 10-50 wt% thermoplastic polyimide resin and 90-50 wt% continuous reinforcing fibres. This is compression moulded by applying progressively increased pressure and temperature in stages; cooling whilst maintaining the pressure and then heating the resulting lay-up under ambient pressure to at least 370°C. Method of explosively forming a multilayered composite material Gupta, S.K. and Pinder, J.T. (Rolls Royce, Inc, Greenwich, CT, USA) US Pat 4 881 314 (21 November 1989) A method of making a fibre-reinforced metal-matrix composite is given. A green compact of powdered metal particles bonded together with a suitable binder is placed against an anvil. At least one layer of fibres is placed on this layer, a second powdered metal layer is laid on the fibre layer and an explosive charge is laid against this. The explosive is detonated to join the layers together and the resultant structure is sintered at a temperature below the reaction temperature of the metal and the fibres. Process for manufacturing a composite panel for shock absorption Ando, Y., Ishige, Y., Kinugasa, T. and Sato, S. (Honda Giken Kabushiki Kaisha, Tokyo, Japan) US Pat 4 882 002 (21 November 1989) The process comprises applying to a surface of a polyolefin member a polyester hotmelting bonding agent which is hardened by adding an isocyanate cross-linking agent. A cross-linking type, hot-melting bonding agent is applied to one surface of a laminating member and the two treated surfaces are placed in contact and bonded together by the application of pressure. Method of producing a reinforced rubber hose by using a plastic mandrel Ohkita, K., Ogata, K. and Niwa, K. (Tokai Rubber Industries Ltd, Aichi, Japan) US Pat 4 882 101 (21 November 1989) A long plastic mandrel is extruded, an unvul-
canized inner rube tube is extruded onto this mandrel and a reinforcing layer is then formed on the outer surface of the tube. An outer unvulcanized tube is extruded around this and the whole is vulcanized. The long hose and contained mandrel are then cut into suitable lengths and the mandrel removed. The pieces of mandrel are crushed and recycled through the extruder. Moulding of fibre reinforced plastic articles Radvan, B. and Willis, A.J. (Wiggins Teape Group Limited, Basingstoke, UK) US Pat 4 882 114 (21 November 1989) A foamed aqueous dispersion is formed from 20-60 wt% single, discrete fibres 7-50 mm long with a Young's modulus > 10 GPa and 40-80 wt% of an unconsolidated particulate plastic selected from the group consisting of a thermoplastic and a thermosetting material with a particle size < 1.5 mm. This is laid down and drained on a forminous support to form a web which is transferred to an oven where it is heated first to remove residual moisture and then to bond the fibrous and plastic components together in such a fashion that the particulate form of the plastic is substantially maintained. The resultant sheet is passed through heated air to a temperature at which the viscosity of the thermoplastic component is sufficiently low to permit moulding; the sheet is then transferred to a compression mould and subjected to a predetermined pressure to produce the shaped composite article. Improved production of carbon fibres Beneke, H. and Peter, S. (Rutgerswerke AG, FRG) US Pat 4 882 139 (21 November 1989) Purified and polymerized concentrated carbon fibre precursor is formed by dissolving a supercritical gas in mesophase pitch at a pressure of 1-3.5 × 107 Pa at a temperature up to 150 K below the melting point of the mesophase pitch to form a low viscosity melt. This is separated into an isotropic phase and an anisotropic carbon fibre precursor that is spun at temperature into fibres which are oxidized, carbonized and optionally graphitized.
COMPOSITES. MAY 1991
257