Method and mold for fabricating an aerodynamic airframe structure Engelke, C.W., Sutton, G.E. and Potter, S.E. (The Boeing Company, Seattle, WA, USA) US Pat4 521 354 (4 June 1985) This two-part mould has a cavity for receiving an external stiffener skin with injection holes along its length, a runner along one side of the cavity and a series of gates joining the runner to the cavity and indexed to the injection holes. During fabrication of the airframe structure, foam is introduced along the length of the runner and through the gates under pressure so that the foam fills the external skin in the cavity through the injection holes. The foam adheres to the skin and forms an elastic foundation for it Method of producing ceramic ware Kitajima, N., Tachibana, Y., Muraki, A. and Kuzuoka, S. (Toppan Printing Company Ltd, Tokyo, Japan) US Pat 4 521 355 (4 June 1985) Patterned ceramic ware is formed by this process which first involves making at least two kinds of wet sheets of ceramic raw material by a wet paper-making method from different aqueous suspensions of fibrous material ceramic raw clay and a colourant Stacking and cutting operations are then performed at least once when the water content of the sheets is 20-50 wt %. The resultant mass is shaped and fired. Method of making multi-layer metal core circuit board laminate with a controlled thermal coefficient of expansion Hanson, J.R., Hauser, J.L, Kilfeather, J.F. and Hendriks, H.B. (General Electric Company, Schenectady, NY, USA) US Pat 4 522 667 (11 June 1985) This laminate comprises in sequence, an uppermost conductive layer of copper foil a bonding layer of resin-impregnated glass cloth, a stabilizing layer of metal with a coefficient of thermal expansion less than that of the nonmetal portions and the copper layer, a bonding layer, a printed circuit board layer, a bonding layer and a lowermost copper foil layer. The coefficient of thermal expansion of the complete laminate is less than that of the bonding layers and the copper conductive layers. Process for preparing an anisotropic aromatic pitch Dickakian, G.B. (E.L DuPont de Nemours and Company, Wilmington, DE, USA) US Pat4 522 701 (11 June 1985) A pitch containing 1-15% toluene insolubles from a catalytic cracking residue is heat treated at 410-500°C for < 2 hours at atmospheric or reduced pressure to obtain a toluene insoluble level of 30 wt % while minimizing the quinoline insolubles to < 3 wt %. The distillable oil is then stripped from the pitch to give an aromatic pitch with an anisotropic structure. Method of fabricating layer insulation for use in high-voltage electrical equipment McLoughlin, J.IL (General Electric Company, Schenectady, NY, USA) US Pat 4 522 771 (11 June 1985) A mixture of inorganic particles, cement and a fluid carrier vehicle is applied to an intermingled array of inorganic fibres and the product pressed into a single, generally planar layer in which the inorganic fibres reinforce the layer and the cement bonds the particles and the fibres. The carrier fluid is then removed.
COMPOSITES. APRIL 1986
Process for producing carbon fiber or graphite fiber Yoshinark O., Kawakatsu, Y. and Fukuizumk H. (Toho Beslon Co Ltd, Tokyo, Japan) USPat4 522 801 (11 June 1985) Fluffing and coalescence of acrylic carbon fibres are minimized in this process which involves treating a preoxidized fibre strand, derived from acrylonitrile, with an aqueous solution containing polyethylene oxide (of MW > 105) and methyl cellulose, ethylcellulose or hydroxyethyl cellulose, drying the treated fibre strand at < 250°C and then carbonizing. The acrylonitrile fibre comprises a polyacrylonitrile or a copolymer of a vinyl compound and > 90 wt % of acrylonitrile.
Filament winding machine Feusi, M., Huber, J., Oswald, H. and Pfyffer, P. (Rieter Machine Works Ltd, Winterthur, Switzerland) US Pat4 524 918 (25 June 1985) The detailed action of a thread winder for a filament winding machine is described.
Method of manufacture of honeycomb noise attenuation structure for high temperature applications Blair, W. (Rohr Industries, Chula Vista, CA, USA) US Pat 4 522 859 (11 June 1985) A noise attenuation structure for high temperature applications is formed from a central honeycomb cellular core sandwiched between an imperforate and a perforate sheet, the outer surface of the perforate sheet having an overlay of a single layer of metal. It is formed by pressing and heating a stacked assembly of components in a vacuum furnace.
Method of winding on foam mandrel Bowen` D.H. (United Kingdom Atomic Energy Authority, London, England) US Pat 4 525 228 (25 June 1985) An FRP article is produced by winding resinimpregnated filaments on a mandrel comprising a relatively low density cellular material about a stiff axial spine. After partial cure of the resin, at least part of t h e mandrel cellular material is removed from within the article so that the resin-impregnated filaments conform to the shape of the remaining part of the mandrel before cure is completed.
Process of making coated glass fiber reinforced composites Hergenrother, W.L (The Firestone Tire & Rubber Company, Akron, OIL USA) US Pat4 524 040 (18 June 1985) A high ratio of flexural strength to density and water resistance is claimed for a glass fibrereinforced thermosetting resin composite in which the glass fibres are coated with an adduct of the reaction between 1,2-polybutadiene and maleic anhydride (weight ratio of the adduct components 100:1 to 1.5:l). A process for the production of the composite is also described.
Process for the manufacture of compact composite carbonaceous materials by densification of porous carbonaceous substrates Jamet, J., Pompeau, J.-J., Omnes, J. and Le Pennec, C. (Commissariat a rEnergie Atomique, Paris and Office National d'Etudes et de la Recherche Aerospatiales, Chatilcon, both of France) US Pat 4 525 337 (25 June 1985) A porous substrate comprising a 20 mm thick 3D network of continuous carbon fibres is densified by decomposing a liquid hydrocarbon substance having a free-carbon content of ~30% in the presence of the substrate. The decomposition is effected in a closed reactor under heat and pressure.
Process of producing hydraulically setting extruding materials Genba, T. and Okazakk M. (Kuraray Co Ltd, Kurashiki, Japan) US Pat 4 524 042 (18 June 1985) PVA fibres of 200-10 000 denier, which have an aspect ratio of 50-700, are used to reinforce cement 60% or more of the fibre bundles are split into single fibres during extrusion. Process for the manufacture of products from reinforced polyester resins (McDougak J.R., Morrow, OIL USA) US Pat4 524 043 (18 June 1985) First, a mixture is formed of unsaturated polyester resin, a cross-linking monomer, reinforcing material and microcapsules, 5-200 p m in diameter, containing a liquid crosslinking initiator. It is then introduced into a mould and heat and pressure applied to fill the cavity uniformly during a first cure stage. The initiator is then released from the microcapsules on heating to 180°C, thereby terminating the first stage of cure and commencing the second, in which the exothermic crosslinking reaction occurs. Maintaining the initiator in microcapsules prolongs the first cure stage and permits the use of increased moulding temperatures. In-flight monitoring of composite structural components such as helicopter rotor blades Wright, D.M, and Kiraly, R.L (Hughes Helicopters Inc, Culver City, CA, USA) USPat4 524 620 (25 June 1985)
The useful life of interchangeable FRP helicopter blades is indicated by a computercontrolled device which monitors the acoustic emissions emitted by the rotor blade under operating stress, counts the AE signals and warns the helicopter crew of a cumulative count and/or stress level approaching a predetermined value associated with catastrophic failure of the blade.
Process for producing wholly aromatic polyamide filaments heat-treated under tension Aoki, A., Hiratsuka, S., Yamaguchi, N. and Makino, S. (Teijin Limited, Osaka, Japan) US Pat 4 525 384 (25 June 1985) An aqueous solution containing graphite, talc, colloidal silica, hydrophobic silica or mica is applied to the surface of wholly aromatic polyamide filaments (formula specified) and dried to obtain covered filaments, which are heat-treated under tension at 300°C or above. Method of making moulded articles (Held, K., Trossingen, FRG) US Pat4 526 737 (2 July 1985) Particles of wood or plant matter are blended with an organic bonding agent; a second portion is blended with a reaction accelerator. Particles of each portion are introduced separately and in a random manner into a heated press and compressed to intimately associate the materials and thereby initiate reaction between the accelerator and bonding agent Method of producing carbon fiber and product thereof Pepper, R.T., Nelson, D.C. and Lewing, D.S. (Fiber Materials Inc, Biddeford, ME, USA) US Pat4 526 770 (2 July 1985) Acrylic polymer fibres comprising recurring acrylonitrile units are permeated with a