Resilient collar rings are attached about a portion of the periphery of the fibre bundles which correspond to the spoke portions. The libre bundle is squeezed by moving the collar rings along the spoke portions to wring the resin-impregnated fibre bundles of excess resin and to expel trapped air bubbles. This imparts a circular cross-section to the bundles. The collar rings are removed from the libre bundles and the structure heat hardened.

Method of manufacturing libre-reinforced resin

Pipe Kittaka, H., Nishizaki, A. and Ichjo, T. (Nitto Boseki Co Ltd. Fukushima. Jaoan) LIS Pat 4 849 IS0 ( 18 Julv 1989) - The method requires forming a plurality of layers by alternatelv winding a thin. loose cloth material and a coniinuous fibre 0n.a core. The core and layers are placed in a split-type outer mould having an inner surface which forms the pipe outer surface. A liquid synthetic resin is impregnated at a pressure of 1-2 kg f cm-* between the outer mould and core so the liquid resin is integrated with the layers and cured into a moulded product. The product is removed from the outer mould and the core removed from the moulded product.

Cone control method for fabricating composite shafts Rumberger, W.E. (The Boeing Co, Seattle, WA, USA) US Pat 4 849 I52 (18 July 1989 J The composite shaft has a cylindrical portion and at least one flared end and is made by dispensing composite material onto a tool to form the cylindrical portion and the flared end of the shaft and applying a force over the inner and outer surfaces of at least one flared end at intermediate stages during the dispensing step for conforming and compacting the composite material. This produces a smooth inner an outer surface at the flared end.

Process for producing silicon carbide whiskers Yamada, M., Hayashida, A., Numanami, K. and Iizuka, T. (ShinEtsu Chemical Co, Tokyo, Japan) US Par 4 849 196 (18 July 1989) A starting mixture of silicon source material (composed predominantly of silicon and oxygen) and a carbonaceous material is reacted at 1400-17OO”CThestartingmixturecontains one or more of Fe, Co, and Ni in the amount 25-2000 ppm based on the silicon ingredient.

Uemura, S., Sohda, Y., Ido, Y. and Yamamoto, S. (Nippon Oil Co, Japan) L/S Pat 4 849 200 (Ii J;!, 1989) - At least one type of fibre from the group spun carbonaceous pitch libre, infusible pitch libre and precarbonized (at 400-8OO’C in inert atmosphere) infusible fibre, is weaved, laminated or mix pulverized with a pitch-based carbon fibre obtained by carbonizing an infusible melt spun carbonaceous pitch at 800-2OOO’C and graphitizing at 2000-3000’C. The resulting product is carbonized under pressure.

Preparation of amorphous metal/magnesium silicates (Marosi, L.. Stabenow, J., Eger, K., Irgang, M. and Zirker (BASF, Ludwigshaven, FRG) C/S Par 4 849 395 ( 18 July 1989) A process is described for preparing an amorphous metal/magnesium silicate of the formula M,Mg,(SiO,).nH,O, where M is a divalent reducible metal from the group consisting of Cu, Fe, Co and Ni, x and y are numbers which together add up to less than

I.5 and n after drying expressed in weight % ranges from 030. The method comprises subjecting a freshly precipitated magnesium silicate to an ion exchange, washing the product and then neutralizing it with alkali.

Method and apparatus for pumping fibre Suspensions Gullichsen, J. (A. Ahlstrom Corp. Karhula, Finland) US Par 4 854 819 (8 August 1989) The method for fluidizing a high consistency fibre suspension consists of using a centrifugal pump connected to a vessel of the fibre suspension. A non-circular rotor in the pump is rotated at a speed sufficient to generate a shear force field within the suspension and so fluidize it.

Method for the preparation of carbon filaments Geus, J. W. and Linowski. J. W. (Dow Chemical Co, Midland, MI, USA) US Pk 4 855 091 (8 August 1989) A thermostable support with substantially completely reduced monocrystalline ferro- magnetic metal particles is exposed to a carbon-containing gas at 250-800°C to cause epitaxial growth of graphite layers at the interface of the metal particle and support. Each metal particle (about 5 nm diameter) forms carbon filaments, the upper temperature limit depends on a precursor metal carbide which forms before nucleation of the carbon filaments. The filaments have a graphite crystal structure and a fishbone-like morphology. Metal particle loading of the support surface is adjusted to control the number of carbon filaments per unit area of support surface.

Method of manufacturing silicon carbide whisker Minamikata, H., Kanno, T., Kanda, M. and Ushijima, H. (Yazaki Corp, Japan) C/S Pat 4 855 II9 (8 August 1989) A reaction zone is heated to 1 lOO-15OO’C and a reducing or inert carrier gas and sulphur- containing organic siloxane reaction materials supplied, the sulphur promoting reaction between silicon and carbon. The reaction materials are thermally decomposed in the vapour phase to react silicon and carbon to give a silicon carbide whisker.

Method for producing chopped strands of carbon fibres Kitamura, T., Shotio, J. and Kodama, A. (Nitto Boseki Co Ltd and Kawasaki Steel Corp, Japan) US Par 4 855 122 (8 August 1989) Chopped strands of carbon fibres with bulk density 0.2-0.8 g cmT3 are produced by spinning a petroleum or coal pitch into continuous pitch tibres, bundling and cutting to a length of I-50 mm and then subjecting the fibres to infusibilization, carbonization or graphitization. Next inorganic or organic binder is applied so that 0.1-3 weight % of the binder adheres to the chopped strands.

Method of manufacturing silicon nitride composition reinforced with silicon carbide whiskers having silicon oxide coating Richon, D.. De Pous, 0. and Fontaine, P. (Battelle Memorial Institutes, Geneva, Swit- zerland) US Par 4 855 262 (8 Aumsr 1989 ) Sic whiskers are oxidized by heat treatment. Alpha-Si,N, powder is ball milled with a sintering aid in the presence of a dispersing phase solvent carrier. The SIC whiskers are admixed with a high proportion of solvent by slow rotation on rolls without balls so as not to break them up. The solvent is evaporated while rotating and the remaining solid

granulated. The granulated body is &statically moulded into a green body at a pressure of 2-4000 bar and then sintered at 1750-1800°C under nitrogen for 5-30 min.

Integral rear wheel suspension for composite material bicycle frame Hollingsworth. R.D. (Cycle Composites Inc, Watsonville, CA, USA) US Par 4 856 801 ( I5 August 1989) The frame has a composite rear wheel suspension made of plies of fibres which are capable of being interwoven with plies of composite material forming other portions of the bicycle frame. The suspension is then fixedly engaged to the frame in a cantilevered manner through a continuous composite material interface.

Fibre-reinforced plastic strut connecting link Shobert, J.P. and Fish, E.B. (Plas/Steel Products Inc, Walkerton, IN, USA) US Pat 4 857 124 (I5 August 1989) The strut is fabricated by producing a braid of woven continuous filaments and applying to a cylinder. A second cylinder is passed through the filaments, the braid is continually formed of woven continuous filaments as a substantially flat double-ply braided ribbon and wrapped about the outer surface of the second cylinder.

Method for producing integral chopped fibre- reinforced glass or glass-ceramic structures Prewo, K.M. and Minford, E. (United Technologies Corporation, Hartford, CT, USA) US Pat 4 857 093 (IS August 1989) The process utilizes a mould and mould inserts to prevent lateral movement. Continuous multifilament carbon fibre yarn is impregnated with a glass or nlass ceramic slurry. The libres are chipped to-discontinuous lengths and the slurry exposed to a high enough temperature to soften it. Pressure is then applied to force the chopped impregnated multifilament yarn into the mould and maintained to prevent relaxation of the composite on cooling until the strain point of the glass is reached.

IMethod of making a composite product especially a vehicle tyre Berger, M. (Pradom Ltd, London, UK) US Pat 4 857 244 (I5 August 1989) The composite material contains reinforcing fibres in a vulcanizable matrix. To fabricate the composite dry fibres are subjected to an electrostatic field and then, while still under the influence of the field to consolidate the bond between the libres and matrix, impregnated with a vulcanizable liquid matrix. The matrix is then vulcanized.

Method for consolidating composite materials Knoll, F.L.(fhe Boeing Co, Seattle, WA, USA) US Pat 4 859 267 (22 August 1989) The method utilizes a fluid bearing having an inflatable cushion that surrounds a cavity. The cavity co-operates with an opposite surface to form a oressurizable chamber when the cushion is inflated. To consolidate the composite at least two plies of material are stacked on a work surface, the tluid bearing is inflated and positioned to form a chamber. The chamber is pressurized with fluid and a load applied to the fluid. The composite material is consolidated without physical contact with the inflatable cushion.

200 Composites Manufacturing September 1990