A b s t r a c t s of Patents
A b s t r a c t s o [ U S p a t e n t s are p r e p a r e d b y Dr R.J. Hand, D e p a r t m e n t o f Engineerin 9 Materials, University o f Sheffield, U K
Fibre-reinforced moulded racquet frame (1 September 1992)
Method of producing reinforced composite materials (Corwin, J.M. of Oak, MI, USA) US Pat 5 172 746 (22 December 1992)
Two cores, both containing a tube with at least one layer of reinforcing fibres, are placed in a mould cavity with string securing members between them; portions of the string securing members project out of the mould into the area that will be surrounded by the moulded frame. The mould is closed and a plastic with a low setting temperature and viscosity is injected into the mould and allowed to harden, thereby encasing the tubes and producing an exterior surface that requires no further machining.
An aluminium alloy is heated to a temperature between 980 and 1200°C and is poured into a heated mould which contains a mass of ceramic reinforcing material. Prior to pouring the mould has been evacuated to a pressure below atmospheric; almost immediately on pouring a pressure of between 1 and 2 atm is applied to the mould so that the oxide layer formed on the alloy is ruptured and the alloy wets the ceramic reinforcement. The alloy is then solidified to produce a ceramic-reinforced composite.
Method of making reinforced structural composite assemblies
Bernadon, E. and Foley, M.F. (The Charles Stark Draper Lab., Inc., Cambridge, MA, USA) US Pal 5 151 277 (29 September 1992) The system comprises a chamber with two opposed flexible diaphragms which m a y be sealed together and a means for supporting a planar fibre workpiece which divides the chamber in two sections. Into at least one of these sections there is means for supplying a resin for impregnating the workpiece. Around the chamber there is a press and die which can be used to form the contained workpiece.
Billiu, C.R. (Wellman Machinery of Michigan, Inc., MI, USA) US Pat 5 173 142 (22 December
Mott, J.C. (Diversified Products Corporation, Opelika, AL, USA) US Pat 5 143 669
1992) Two rigid, fibre-reinforced, electron-beam curable thermoplastic composite members are formed and are fusion-bonded to form a hollow section. The whole is then subjected to electron irradiation to cure the thermoplastic members and thereby produce a hollowsection composite body.
Long fibre reinforced thermoplastic especially for a tennis racket Method for making ceramic composite article Gardner, R.W., Sawyer, C.B., Stewart, R . L and Weiss, D.S. (Corning Inc., Corning, NY, USA) US Pat 5 154 787 (13 October 1992) A continuous prepreg strand, which is formed of one or more inorganic fibres coated or impregnated with a ceramic powder in a softened thermoplastic binder, is collected in a uniform fashion whilst it is heated to prevent solidification of the binder. After this, it is cooled and pressure is applied to form a uniform dense prepreg mat.
Fibrous material-containing composite Singh, R.N. and Gaddipati, A.R. (General Electric Company, Schenectady, NY, USA)
extracted from the interior of the material and the polymer matrix concentration increases at the surface.
Method for continuously forming composite material into a rigid structural member Cavin, M.G. (Graphite Design and Detail, Inc., Boulder, CO, USA) US Pat 5 192 383 (9
March 1993) Uncured layered composite material is pulled incrementally through a forming die to shape it. It is then moved downstream via a series of clamping dies which pull, heat and cool the composite. At all stages the composite is pulled through a liner so that no indentations or parting lines are produced on its surface.
Methods for forming composite tubing having tapered ends Barrier, J.M., Drey, M.D., Montford, L.V. and Tan, S.S. (Kaiser Aerospace and Electronics Corporation, Foster City, CA, USA) US Pat
5 192 384 (9 March 1993) A fabric containing a matrix precursor is formed over an elongated mandrel to produce a structure which is hollow and has tapered ends, at least one of which has an opening that is smaller than the central portion of the mandrel. The mandrel is then disassembled and removed via this opening, after which the material is cured to produce a rigid composite tube.
Davis, S.J. (Prince Manufacturing, Inc., Lawrenceville, NJ, USA) US Pat 5 176 868 (5
January 1993) A method of manufacturing a frame for a sports racket comprises combining long reinforcement fibres with a thermoplastic material to form a flexible tow. A flexible sleeve with the fibres oriented at at least one angle is formed from this tow. The sleeve is packed into a mould in the shape of the frame; the inside of the sleeve is pressurized and the whole is heated so that the thermoplastic melts and flows and the sleeve assumes the shape of the mould. The sleeve is then cooled and solidified whilst t h e i n t e r n a l p r e s s u r i z a t i o n is maintained.
Process for impregnation of glass fibre reinforcement with thermoplastic resins Kim, B.M. (General Electric Company, Schenectady, NY, USA) US Pat 5 194 190 (16
March 1993) In this process for forming a glass fibre composite, a resin is placed in contact with a glass fibre mat, both the resin and the mat are then sealed in a film which has a higher glass transition temperature and melting temperature than the resin. The film is evacuated and the whole exposed to a radio frequency field for a sufficient time to heat the resin to its glass transition or melting temperature so that the resin impregnates the mat.
US Pat 5 160 676 (3 November 1992) A laminated structure, comprising at least one layer of fibrous material deposited between layers of tape, is formed. The tape comprises a ceramic matrix material with a thermal expansion coefficient which is ~ 15% larger than that of the fibrous material and an organic binder. The whole is heated to remove the binder and then is hot-pressed to > 9 5 % density. The resulting composite contains at least 10 vol% fibrous material.
0956-7143/94/04/0243-03 © 1994 Butterworth-Heinemann Ltd
Method of making composites having improved surface properties Sanford, W.M. and Uy, W.C. (E.I. D u Pont de N e m o u r s and Company, Wilmington, DE, USA) US Pat 5 178 812 (12 January 1993) A microcomposite material comprising a microfibrillar-reinforced polymer matrix is treated with a solvent which dissolves the matrix but not the microfibrils. The solvent is removed such that some of the matrix is
Process for preparing advance composite structures Terzian, A. and Trentacosta, J.D. (E.I. du Pont de N e m o u r s and Company, Wilmington, DE, USA) US Pat 5 198 173 (30 March 1993) A preform with a hollow core is placed into an appropriately shaped cavity and one or more of the openings to the core of the preform are plugged. Polymer is introduced into the
COMPOSITES MANUFACTURING Volume 5 Number 4 1994