material has only slight adhesion to the cords to help consume impact energy if the container is hit. Piston rod assembly including preloaded piston head and composite rod Benton, T.L. and Matthews, J.H. (Pneumo Abex Corporation, Boston, MA, USA) US Pat 4 872 370 (10 October 1989) A piston rod assembly is presented, the rod being made of a fibrous composite material. Composite-materials acoustic stringed instrument panel Decker, J.A., Decker, L.M. and Halford, C.J. (Kuau Technology Ltd, Wailuku, HI, USA) US Pat 4 873 907 (17 October 1989) A soundboard for an acoustic stringed instrument consists of a composite plate comprising aramid fibres and graphite in a resin matrix with a gel coating. High strength laminate Rasmussen, O.-B. (CH-6318 Walchwil/Zug, Switzerland) US Pat 4 874 653 (17 October 1989) A high strength laminate consists of at least two weakly adhered, biaxially oriented, polymer films. The films are formed of a polymer composition with a distinct fibrous morphology which is generally unidirectional on a macroscale but with fibre portions strongly deflected from this grain direction on a microscale.
MATERIALS Glass fibre product for use in the reinforcement of fiuororesin Inoguchi, H. and Watanabe, S. (Nitro Boseki Co Ltd, Japan) US Pat 4 865 910 (12 September 1989) A glass fibre for the reinforcement of fluororesin is pre-treated with perfluoroalkylsilane. Method of making reinforcing materials having an improved reinforcing material therein Hibbard, B.B., Mann, J.A., Potepan, A.K., White, R.E., Knight, B.T. and Bryant, H.H. (BASF Corporation, Williamsburg, VA, USA) US Pat 4 866109 (12 September 1989) Concrete is reinforced with homopolymeric acrylic fibres. Thermoplastic compositions, resin moulded product for vehicle lining and method for manufacturing the same Lee, C.Y. (Han I1 E'wha Co Ltd, Seoul, Republic of Korea) US Pat 4 866 110 (12 September 1989) A composition is given which contains 50-60 wt% polypropylene, 30-35 wt% wood flour, 2-3% defatted rice bran powder, 2-3 wt% asbestos, 1.7-4.0 wt% glass fibres and 0.81.2 wt% calcined diatomaceous earth. Carbonaceous fibre-reinforced composites McCullough, F.P., Dick, C.R. and Brewster, S.L. (Dow Chemical Company, Midland, MI, USA) US Pat 4 868 038 (19 September 1989) A fibre-reinforced composite material comprising a synthetic resin matrix containing a multiplicity of reinforcing carbonaceous fibres is described. The fibres comprise resil-
COMPOSITES. MARCH 1991
ient, shaped, reforming, elongatable, nonlinear, non-flammable carbonaceous fibres with a reversible deflection ratio of greater than 1.2:1 and an aspect ratio of greater than 10:1. Microdisperse polymer/liquid crystal composite Leslie, T.M. and Khanarian, G. (Hoechst Celanese Corp, Somerville, N J, USA) US Pat 4 869 847 (26 September 1989) A material which is incapable of substantially scattering visible light is made of droplets of a liquid crystal dispersed in a light transmissive matrix. The liquid crystal is soluble in the matrix-forming composition and on solidification the droplets form with 85% of them having a diameter less than 0.1 ~tm. Fibre-reinforced silicon nitride ceramics Corbin, N.D., Hartline, S.D. and Rosetti, G.A. (Norton Company, Worcester, MA, USA) US Pat 4 869 943 (26 September 1989) The matrix is reaction-bonded silicon nitride and it is reinforced with 20-80 vol % SiC fibres of at least 1 mm length. Crack deflection zones with different mechanical properties than the matrix or fibre occupy a predominant portion of the space around the fibres. The composite has non-catastrophic failure and a modulus of rupture of at least 550 MPa. Rubber containing aramid pulp reinforcement Brown, R.J. and Scriver, R.M. (The Goodyear Tire and Rubber Company, Akron, OH, USA) US Pat 4 871 004 (3 October 1989) A vulcanized elastomer composite is formed from a premix consisting of fibrillated aramid fibres and one or more particulate reinforcing agents (carbon black, silica or clay) in sufficient quantities to cause partitioning of the aramid fibres and a vulcanizable elastomer, the resulting mixture being cured. The aramid fibres in the premix have a trunk portion between 0.2 and 5 mm long and aspect ratio of greater than 100 with fibrils extending from this trunk. The fibres do not exceed 5 parts by weight per 100 of the elastomer in the composition. Composites comprising silicon carbide fibres dispersed in magnesium-aluminate matrix and fabrication thereof and of other composites by sinter forcing Panda, P.C., Seydel, E.R. and Raj, R. (Jupiter Technologies, Inc, and Cornell Research Foundation, Inc, Ithaca, NY, USA) US Pat4871 496 (3 October1989) Ceramic-ceramic composites consisting of a dispersion of 10 to 50 vol% silicon carbide fibres in a matrix of MgO.AI20 3 are described. These are manufactured by cold pressing a mixture of MgO and Ai20 3 (in a molar ratio of 1:2) containing the dispersed silicon carbide fibres. The preform is isothermically sinter forged in an inert environment at temperatures between 1200°C and 1625°C at strain rates of between 104 s-1 and 10-2 s-l to produce an at least 98% dense composite. Artificial marble Kamiya, T., Suzuki, M., Obata, Y., Watanabe, M. and Matsuoka, I. (Aica Kogyo Co Ltd, Nagoya, Japan) US Pat 4 871 596 (3 October 1989) Artificial marble is produced from a moulded composite sheet consisting of fibrous sub-
strates impregnated with a melamine resin and laminated on top of one another. The resin is selected from the group consisting of a melamine-formaldehyde resin and an alcohol-etherified melamine-formaldehyde resin with a formaldehyde to melamine ratio of 1.2-3.0 and 5-50 wt% of a modifier for the resin (one of alcohol, glycol, acrylic monomer, acrylic oligomer and vinyl acetate monomer or mixtures thereof). Reinforced polymer compositions having excellent distinctness of image Martinez, E.C. (The Dow Chemical Company, Midland, MI, USA) US Pat 4 871 789 (3 October 1989) A filled polymer composition is given which consists of a polyurethane and/or polyurea matrix, a reinforcing filler and a supplementary filler. The reinforcing filler particles should have an aspect ratio of at least 4; an average length of the particles should be at least 20 ~tm (or at least 40 ~tm if the filler is woUastonite); and be present in such quantities that the reinforcement gives enhanced physical properties. The supplementary filler is either wollastonite, with an aspect ratio of 7 or less and an average particle length of 35 ~tm or less, or another inorganic compound, with a median particle size of 10 ~tm or less and an aspect ratio of 4 or less. The supplementary filler is characterized such that the overall composition exhibits a distinctness of image of at least 80 DOI units. Polymerisable cement mixtures Engelbrecht, J. (Ernst Muhlbauer KG, Hamburg, FRG) US Pat 4 872 936 (10 October 1989) A polymerizable cement mixture contains a monomer, oligomer or prepolymer with an acid group or reactive acid derivative, a reactive filler and a curing agent. The cement mixture may be used to adhere oxidic, mineral, vitreous, ceramic, metallic, biological and acrylic materials to each other. Fibre reinforced stampable thermoplastic sheet Giles, H.F. (General Electric Company, Pittsfield, MA, USA) US Pat 4 873 133 (10 October 1989) A fibre-reinforced stampable sheet consisting of a thermoplastic resin surface layer and a reinforcing fibre mat made of a thermoplastic resin support film with penetrating fibres is described. One side of the mat has the minor portion of the fibres on it and this is positioned adjacent to the surface layer. Fibre for composite reinforcement with antiblocking rmish Marshall, R.M. (Allied-Signal Inc, Morris County, N J, USA) US Pat 4 873 144 (10 October 1989) A high tenacity reinforcing fibre made from polyester, aliphatic polyamide or combinations thereof for reinforcing plastic composites is described. The fibre is coated with a composition consisting of an aqueous solution, carboxyl-terminated, oil-free alkyd resin, which has a degree of esterification below its gel point sufficient to enhance the stiffness of the fibre, and an aqueous emulsion of oxidized polyethylene present in amounts to provide enhanced anti-blocking properties.