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Friction material for railway disc pads
Abstracts of patents UK and US patents are prepared by Ors F.R. Jones and R.J. Hand of the University of Sheffield, UK
UK PATENTS Impact resistant fibrous laminate (ICI Americas Inc, USA) GB2242 160A (25 September 1991) An isocyanate-terminated prepolymer and organic carbonate such as propylene carbonate are impregnated into a wide variety of cellulosic materials (such as paper) to give a laminatable 'prepreg'. It may contain glass fibres. The carbonate acts as a reactable viscosity modifier for the impregnation by in situ decomposition into a glycol which can react with the isocyanate prepolymer. These paper-based laminates have superior mechanical properties and have applications such as tables, chairs and tubes. Fibre reinforced elastomeric sheet (T and N Technology Ltd, UK) GB 2 242 859 A (16 October 1991) The title material, which is useful for gaskets, is a laminate of non-woven fibrous fabric---e.g., glass or aramid tissue--impregnated with a suspension of inorganic filler such as calcium carbonate in a curable elastomer, using solution techniques. Lamination as opposed to the conventional 'calendering' produces a less anisotropic material. Siliconised silicon carbide article (T and N Technology Ltd, UK) GB 2 243 601 A (6 November 1991) The title artefact is made by injection moulding a mixture of SiC particles and organic binder, and removing the latter by heat to yield a porous SiC article which can be impregnated with molten silicon to convert the residual carbon to SiC. The latter acts as a binder. The technique has been improved by ensuring that the sprue from the original moulding is hollow and can act as a conduit for the molten silicon. The sprue has excellent properties and can be left intact. A typical example is a sealing ring. Friction material for railway disc pads (Ferodo Ltd, UK) GB 2 244 061 A (20 November 1991) The title materials comprise a reinforcing fibre, a polymeric binder and particulate material. The binder is a heat-resistant EPDM rubber which may optionally contain a resin. Thermoplastic composite material (Rogers Corp, USA) GB 2 244 274 A (27 November 1991) A highly filled thermoplastic extrudate, for use as a printed circuit board material, comprises a rubber-coated ceramic filler in a fluoro or chlorofluoro-carbon polymer. The filler is a fused silica surface treated with a silicone rubber, although glass spheres or microcrystalline silica are also described. Oxides which reduce filler-induced degradation can also be included.
204
COMPOSITES. MAY 1992
Coated filler particles and method for making same (Rogers Corp, USA) GB 2 244 489 A (4 December 1991) Fillers for composites which are based on silicone-rubber-coated minerals are described. The latter can be a range of particulates, microspheres or fibres. They are prepared by reacting a monofunctionalterminated polysiloxane with a multifunctional silane and silane cross-linking agent to form a reactive silicone network. They are useful as fillers for a range of thermosets and thermoplastics.
US PATENTS COMPONENTS Ceramic composite valve for internal combustion engines and the like Berneburg, P.L. and Rice, R.W. (W.R. Grace & Co-Conn, New York, NY, USA) US Pat 4 928 645 (29 May 1990) A finished ceramic composite valve or preform valve is described, the stem of which comprises a fibrous ceramic sleeving packed with an axially aligned unidirectional cluster of ceramic reinforcing fibres. This is attached to a ceramic bell which contains discontinuous ceramic fibres and is shaped to mate with the valve seat of the engine. Conveyor belt of PVC provided with a compound layer of reinforcing material and a process of weaving said reinforcing layer van Calker, F.R. (Akzo NV, Arnhem, The Netherlands) US Pat 4 928 812 (29 May 1990) A polyvinyl chloride conveyor belt contains a reinforcing compound woven fabric. The fabric has two outer layers of cotten yarns adhered to the PVC matrix and these layers are interconnected to the middle layer by binder warp yarns or filaments. The middle layer has aramid primary warp cables or cords which extend in the direction of the belt. The spaces between these warp cables are 0.5-2 times as wide as the outer diameter of the cables and are filled rectilinearly with nonaramid cotton filling warp members. Titanium diboride ceramic fibre composites for Hall--Heroult cells Besmann, T.M. and Lowden, R.A. (Martin Marietta Energy Systems Inc, Oak Ridge, TN, USA) US Pat 4 929 328 (29 May 1990) A preform fibre matrix is infiltrated with titanium diboride by holding the matrix at about 900°C whilst passing hydrogen, boron trichioride and titanium tetrachloride through the matrix. The fibres may be silicon carbide, carbon, alumina, mullite, aluminium nitride, boron nitride or mixtures thereof and the matrix has a means to mount the finished cathode in a HalI-Heroult cell for aluminium smelting.
Hollow shell fibre reinforced resin impregnated bicycle wheel construction and method therefore Lewis, R.H. (Hamilton-Sattui, Napa, CA, USA) US Pat 4 930 843 (5 June 1990) A bicycle wheel with not more than five spokes is described wherein both the spokes and the central hub have a hollow fibrereinforced resin construction. The rim consists of fibre-reinforced resin. Structure with a multiply fabric reinforcement and a method for producing same B6ttger, W. and Bicdermann, K. (Vorwerk & Co Interholding GmbH, FRG) US Pat 4 931 345 (5 June 1990) A multi-ply fabric comprises a yarn of aramid fibre, carbon fibre, ceramic fibre or fibreglass with filling weft threads of polyamide or polypropylene extending between the plies. The whole is impregnated with a resin and then cured. Pultruded composite sign and process therefore Perko, J.E., Wirth, G.J. and Foxgrovcr, B.A. (W.H. Brady Co, Milwaukee, Wl, USA) US Pat 4 935 279 (19 June 1990) A composite sign consists of a longitudinally continuous sheet of printed matter attached to a fibrous component. The whole of this sheet is pulled through a resinous component and a forming die so that the sheet is encapsulated by the resin and the information is visible. Transmission belt with anisotropic composite material having an elastomer matrix Colley, R., Lecouturicr, F. and Ledcvehat, C. (Caoutchouc Manufacture et Plastiques, Versailles, France) US Pat 4 936 814 (26 June
1990) A transmission belt comprises at least one layer. Each layer contains a fibre reinforcement means including fibres with a maximum length of about 30 mm generally uniaxially orientated in an elastomeric matrix containing at least one thermosetting resin. The direction of reinforcement of at least one layer is perpendicular to the longitudinal axis of the belt. Composite sign post Zion, E.M. and Freeman, J,E. (John E. Freeman, Big Spring, TX, USA) US Pat 4 939 037 (3 July 1990) A thin-walled tubular sign post with a slot-in ground anchor and locking means comprises at least one segment, each segment being constructed of a glass fibre-reinforced resin. The glass fibre content is between 55 and 75 weight % and the fibres arc orientated transversely to the longitudinal axis of the post.
MATERIAL S Preform wire for a carbon fibre reinforced aluminium composite material and a method for manufacturing the same
UK PATENTS Impact resistant fibrous laminate (ICI Americas Inc, USA) GB2242 160A (25 September 1991) An isocyanate-terminated prepolymer and organic carbonate such as propylene carbonate are impregnated into a wide variety of cellulosic materials (such as paper) to give a laminatable 'prepreg'. It may contain glass fibres. The carbonate acts as a reactable viscosity modifier for the impregnation by in situ decomposition into a glycol which can react with the isocyanate prepolymer. These paper-based laminates have superior mechanical properties and have applications such as tables, chairs and tubes. Fibre reinforced elastomeric sheet (T and N Technology Ltd, UK) GB 2 242 859 A (16 October 1991) The title material, which is useful for gaskets, is a laminate of non-woven fibrous fabric---e.g., glass or aramid tissue--impregnated with a suspension of inorganic filler such as calcium carbonate in a curable elastomer, using solution techniques. Lamination as opposed to the conventional 'calendering' produces a less anisotropic material. Siliconised silicon carbide article (T and N Technology Ltd, UK) GB 2 243 601 A (6 November 1991) The title artefact is made by injection moulding a mixture of SiC particles and organic binder, and removing the latter by heat to yield a porous SiC article which can be impregnated with molten silicon to convert the residual carbon to SiC. The latter acts as a binder. The technique has been improved by ensuring that the sprue from the original moulding is hollow and can act as a conduit for the molten silicon. The sprue has excellent properties and can be left intact. A typical example is a sealing ring. Friction material for railway disc pads (Ferodo Ltd, UK) GB 2 244 061 A (20 November 1991) The title materials comprise a reinforcing fibre, a polymeric binder and particulate material. The binder is a heat-resistant EPDM rubber which may optionally contain a resin. Thermoplastic composite material (Rogers Corp, USA) GB 2 244 274 A (27 November 1991) A highly filled thermoplastic extrudate, for use as a printed circuit board material, comprises a rubber-coated ceramic filler in a fluoro or chlorofluoro-carbon polymer. The filler is a fused silica surface treated with a silicone rubber, although glass spheres or microcrystalline silica are also described. Oxides which reduce filler-induced degradation can also be included.
204
COMPOSITES. MAY 1992
Coated filler particles and method for making same (Rogers Corp, USA) GB 2 244 489 A (4 December 1991) Fillers for composites which are based on silicone-rubber-coated minerals are described. The latter can be a range of particulates, microspheres or fibres. They are prepared by reacting a monofunctionalterminated polysiloxane with a multifunctional silane and silane cross-linking agent to form a reactive silicone network. They are useful as fillers for a range of thermosets and thermoplastics.
US PATENTS COMPONENTS Ceramic composite valve for internal combustion engines and the like Berneburg, P.L. and Rice, R.W. (W.R. Grace & Co-Conn, New York, NY, USA) US Pat 4 928 645 (29 May 1990) A finished ceramic composite valve or preform valve is described, the stem of which comprises a fibrous ceramic sleeving packed with an axially aligned unidirectional cluster of ceramic reinforcing fibres. This is attached to a ceramic bell which contains discontinuous ceramic fibres and is shaped to mate with the valve seat of the engine. Conveyor belt of PVC provided with a compound layer of reinforcing material and a process of weaving said reinforcing layer van Calker, F.R. (Akzo NV, Arnhem, The Netherlands) US Pat 4 928 812 (29 May 1990) A polyvinyl chloride conveyor belt contains a reinforcing compound woven fabric. The fabric has two outer layers of cotten yarns adhered to the PVC matrix and these layers are interconnected to the middle layer by binder warp yarns or filaments. The middle layer has aramid primary warp cables or cords which extend in the direction of the belt. The spaces between these warp cables are 0.5-2 times as wide as the outer diameter of the cables and are filled rectilinearly with nonaramid cotton filling warp members. Titanium diboride ceramic fibre composites for Hall--Heroult cells Besmann, T.M. and Lowden, R.A. (Martin Marietta Energy Systems Inc, Oak Ridge, TN, USA) US Pat 4 929 328 (29 May 1990) A preform fibre matrix is infiltrated with titanium diboride by holding the matrix at about 900°C whilst passing hydrogen, boron trichioride and titanium tetrachloride through the matrix. The fibres may be silicon carbide, carbon, alumina, mullite, aluminium nitride, boron nitride or mixtures thereof and the matrix has a means to mount the finished cathode in a HalI-Heroult cell for aluminium smelting.
Hollow shell fibre reinforced resin impregnated bicycle wheel construction and method therefore Lewis, R.H. (Hamilton-Sattui, Napa, CA, USA) US Pat 4 930 843 (5 June 1990) A bicycle wheel with not more than five spokes is described wherein both the spokes and the central hub have a hollow fibrereinforced resin construction. The rim consists of fibre-reinforced resin. Structure with a multiply fabric reinforcement and a method for producing same B6ttger, W. and Bicdermann, K. (Vorwerk & Co Interholding GmbH, FRG) US Pat 4 931 345 (5 June 1990) A multi-ply fabric comprises a yarn of aramid fibre, carbon fibre, ceramic fibre or fibreglass with filling weft threads of polyamide or polypropylene extending between the plies. The whole is impregnated with a resin and then cured. Pultruded composite sign and process therefore Perko, J.E., Wirth, G.J. and Foxgrovcr, B.A. (W.H. Brady Co, Milwaukee, Wl, USA) US Pat 4 935 279 (19 June 1990) A composite sign consists of a longitudinally continuous sheet of printed matter attached to a fibrous component. The whole of this sheet is pulled through a resinous component and a forming die so that the sheet is encapsulated by the resin and the information is visible. Transmission belt with anisotropic composite material having an elastomer matrix Colley, R., Lecouturicr, F. and Ledcvehat, C. (Caoutchouc Manufacture et Plastiques, Versailles, France) US Pat 4 936 814 (26 June
1990) A transmission belt comprises at least one layer. Each layer contains a fibre reinforcement means including fibres with a maximum length of about 30 mm generally uniaxially orientated in an elastomeric matrix containing at least one thermosetting resin. The direction of reinforcement of at least one layer is perpendicular to the longitudinal axis of the belt. Composite sign post Zion, E.M. and Freeman, J,E. (John E. Freeman, Big Spring, TX, USA) US Pat 4 939 037 (3 July 1990) A thin-walled tubular sign post with a slot-in ground anchor and locking means comprises at least one segment, each segment being constructed of a glass fibre-reinforced resin. The glass fibre content is between 55 and 75 weight % and the fibres arc orientated transversely to the longitudinal axis of the post.
MATERIAL S Preform wire for a carbon fibre reinforced aluminium composite material and a method for manufacturing the same