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Method and apparatus for vacuum compression of laminated sheet material
Journal Vol 23 No 3 (May/June 1987) pp 35-42 A n investigation into the causes of microcracking in graphite fibre reinforced PMR-15 laminates and into the effects of cure temperature on microcracking and mechanical properties was carried out. It was found that the tendency to microcrack is related to residual thermal stresses arising from the mismatch of fibre and resin thermal expansion coefficients, high cure temperature and resin modulus. By curing at low temperatures (280-290°C) the tendancy of the composites to microcrack could be reduced. Laminates cured at these temperatures had acceptable mechanical properties at room and elevated temperatures and after longterm ageing.
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Radiation effects on graphite fiber reinforced composites Memory, J. D., Fornes, R. E. and Gilbert, R. D. Journal of Reinforced Plastics and Composites Vol 7 (January 1988) pp 33-65 This paper is a review of the effects of radiation on graphite fibre reinforced polymer composites. It is generally concluded that doses of up to thousands of megarads do not significantly degrade the tensile strength or modulus, provided the irradiation occurs in an oxygen free environment. Reinforced cyanoacrylates as repair materials Demetrion, P. P., Polyzois, G. L. and Andreopoulos, A. G. Journal of Materials Science Letters Vol 7 (1988) pp 13-14 The mechanical properties of dental acrylic
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resin based specimens fractured and repaired with a cyanoacrylate reinforced and nonreinforced adhesive have been evaluated before and after ageing in synthetic saliva. The reinforced material appeared weaker initially but after ageing it gave better results when compared to the unreinforced adhesive. SEM observations of fractured flyashpolyester composites Chand, N. Journal of Materials Science Letters Vol 7 (1988) pp 36-38 The impact strength and ultimate tensile strength of flyash reinforced polyester resin has been reported, for various volume fractions of flyash. The corresponding fracture surfaces are also shown.
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Abstracts of British Patents are prepared by Dr F . R . Jones, Department of Ceramics, Glasses and Polymers, University of Sheffield, UK
U K PATE NTS COMPONENTS Structural panel (Fischer Gmbh, Austria) GB 2 197 820 A (2 June 1988) A structural honeycomb panel intended for flooring panels in eg, aircraft is described. It consists of an aluminium foil or other high temperature softening material which is placed fast beneath the outer-lamina of FRP so that the FRP can char or leave an insulating layer of fibres to enhance the performance of the underlying metal or high temperature foil which is normally <0.1 mm thick.
MATERIALS Composite sheet material (Structural Polymer Systems Ltd, UK) GB 2 195 952 A (20 April 1988) A fibre composite laminate consisting of FRP outer plies with an innercore of knitted or other open weave fibrous 'honeycomblike' layer in which the resin (eg, epoxy) matrix has penetrated the fibres, to give good compression resistance. Dough moulding compounds for producing moulded building materials (Advanced Plastics (South Wales) Ltd, UK GB 2 196 344 A (27 April 1988) A polyester resin filled with 3-12 ~ W of short glass fibre and graded filler particles from 25-1000 ~tm suitable for roofing tiles, is described. The weight fraction of resin is 16-18 g.
COMPOSITES. SEPTEMBER 1988
Resin composition containing organoclays (EEC International Ltd, UK),GB 2 196 970 A (11 May 1988) Quaternary ammonium salts of natural oils can be used to coat a smectite clay such as bentonite to produce dispersible thickening (thixotropic) agents for polyester or epoxy resins.
In an extension to GB 2 197305 A, quinoline is used as a plasticiser for preoxidised pitch based fibres during hot isotactic pressing to form a graphitisable preform. Higher moduli can be achieved by this technique.
US PATENTS PROCESSES Method and apparatus for vacuum compression of laminated sheet material (Kabushiki Kaisha Kawakami Seisakusho, Japan) GB 2 195 580 A (13 April 1988) A table for vacuum compressing laminae with a laminate under an air-impermeable sheet. Moulding laminated panels (Polistock N.V., The Netherlands) GB 2 195 940 A (20 April 1988) A method of producing laminated automobile door panels from plastics materials and flexible coating. The latter can be controlled to cover any cut edges of the substrate. High carbon composite (Fiber Materials Inc, USA) GB 2 197 305 A (18 May 1988) Preoxidised PAN fibres are dispersed in a partial solvent or plasticiser which on removal leaves the fibres adhered together by a leachate. For example, a filament wound body remained intact after immersion in boiling ethylene glycol. If hot isotactic pressing is used, water can be used as the 'plasticiser'. The preform can be subsequently carbonised and graphitized. High carbon composite (Fiber Materials Inc, USA) GB 2 197 306 A (18 May 1988)
COMPONENTS Fiber reinforced braided ski core and method for making and apparatus same Fezio, L.J. (K-2 Corporation, Vashon Island, WA, USA) US Pat 4 690 850 (1 September 1987) A wrapped ski core is described comprising a longitudinal core surrounded by many continuous strands of fibres. A claim is also made for a wrapped core in which the torsional and longitudinal stiffness of the ski is varied along its length. Water-vapor-permeable, waterproof, highly elastic films Nomi, H. (Japan Gore-Tex, Inc., Japan) US Pat 4 692 369 (8 September 1987) A composite film comprising a film of expanded, porous, unsintered polytetrafluoroethylene impregnated with a waterv a p o u r - p e r m e a b l e polymeric resin is claimed. The composite film laminated to a two-way stretch fabric by a point-to-point adhesive is also claimed. Thermoplastic sheet Neubauer, J.A., Reese, W.J. and Spencer, D.O. (Azdel, Inc., Shelby, NC, USA) US Pat 4 692 375 (8 September 1987) A thermoplastic fibre glass reinforced sheet comprising a thermoplastic resin filled mat of glass fibre strands is described.
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Radiation effects on graphite fiber reinforced composites Memory, J. D., Fornes, R. E. and Gilbert, R. D. Journal of Reinforced Plastics and Composites Vol 7 (January 1988) pp 33-65 This paper is a review of the effects of radiation on graphite fibre reinforced polymer composites. It is generally concluded that doses of up to thousands of megarads do not significantly degrade the tensile strength or modulus, provided the irradiation occurs in an oxygen free environment. Reinforced cyanoacrylates as repair materials Demetrion, P. P., Polyzois, G. L. and Andreopoulos, A. G. Journal of Materials Science Letters Vol 7 (1988) pp 13-14 The mechanical properties of dental acrylic
r'dcl oF l
resin based specimens fractured and repaired with a cyanoacrylate reinforced and nonreinforced adhesive have been evaluated before and after ageing in synthetic saliva. The reinforced material appeared weaker initially but after ageing it gave better results when compared to the unreinforced adhesive. SEM observations of fractured flyashpolyester composites Chand, N. Journal of Materials Science Letters Vol 7 (1988) pp 36-38 The impact strength and ultimate tensile strength of flyash reinforced polyester resin has been reported, for various volume fractions of flyash. The corresponding fracture surfaces are also shown.
tsnt
Abstracts of British Patents are prepared by Dr F . R . Jones, Department of Ceramics, Glasses and Polymers, University of Sheffield, UK
U K PATE NTS COMPONENTS Structural panel (Fischer Gmbh, Austria) GB 2 197 820 A (2 June 1988) A structural honeycomb panel intended for flooring panels in eg, aircraft is described. It consists of an aluminium foil or other high temperature softening material which is placed fast beneath the outer-lamina of FRP so that the FRP can char or leave an insulating layer of fibres to enhance the performance of the underlying metal or high temperature foil which is normally <0.1 mm thick.
MATERIALS Composite sheet material (Structural Polymer Systems Ltd, UK) GB 2 195 952 A (20 April 1988) A fibre composite laminate consisting of FRP outer plies with an innercore of knitted or other open weave fibrous 'honeycomblike' layer in which the resin (eg, epoxy) matrix has penetrated the fibres, to give good compression resistance. Dough moulding compounds for producing moulded building materials (Advanced Plastics (South Wales) Ltd, UK GB 2 196 344 A (27 April 1988) A polyester resin filled with 3-12 ~ W of short glass fibre and graded filler particles from 25-1000 ~tm suitable for roofing tiles, is described. The weight fraction of resin is 16-18 g.
COMPOSITES. SEPTEMBER 1988
Resin composition containing organoclays (EEC International Ltd, UK),GB 2 196 970 A (11 May 1988) Quaternary ammonium salts of natural oils can be used to coat a smectite clay such as bentonite to produce dispersible thickening (thixotropic) agents for polyester or epoxy resins.
In an extension to GB 2 197305 A, quinoline is used as a plasticiser for preoxidised pitch based fibres during hot isotactic pressing to form a graphitisable preform. Higher moduli can be achieved by this technique.
US PATENTS PROCESSES Method and apparatus for vacuum compression of laminated sheet material (Kabushiki Kaisha Kawakami Seisakusho, Japan) GB 2 195 580 A (13 April 1988) A table for vacuum compressing laminae with a laminate under an air-impermeable sheet. Moulding laminated panels (Polistock N.V., The Netherlands) GB 2 195 940 A (20 April 1988) A method of producing laminated automobile door panels from plastics materials and flexible coating. The latter can be controlled to cover any cut edges of the substrate. High carbon composite (Fiber Materials Inc, USA) GB 2 197 305 A (18 May 1988) Preoxidised PAN fibres are dispersed in a partial solvent or plasticiser which on removal leaves the fibres adhered together by a leachate. For example, a filament wound body remained intact after immersion in boiling ethylene glycol. If hot isotactic pressing is used, water can be used as the 'plasticiser'. The preform can be subsequently carbonised and graphitized. High carbon composite (Fiber Materials Inc, USA) GB 2 197 306 A (18 May 1988)
COMPONENTS Fiber reinforced braided ski core and method for making and apparatus same Fezio, L.J. (K-2 Corporation, Vashon Island, WA, USA) US Pat 4 690 850 (1 September 1987) A wrapped ski core is described comprising a longitudinal core surrounded by many continuous strands of fibres. A claim is also made for a wrapped core in which the torsional and longitudinal stiffness of the ski is varied along its length. Water-vapor-permeable, waterproof, highly elastic films Nomi, H. (Japan Gore-Tex, Inc., Japan) US Pat 4 692 369 (8 September 1987) A composite film comprising a film of expanded, porous, unsintered polytetrafluoroethylene impregnated with a waterv a p o u r - p e r m e a b l e polymeric resin is claimed. The composite film laminated to a two-way stretch fabric by a point-to-point adhesive is also claimed. Thermoplastic sheet Neubauer, J.A., Reese, W.J. and Spencer, D.O. (Azdel, Inc., Shelby, NC, USA) US Pat 4 692 375 (8 September 1987) A thermoplastic fibre glass reinforced sheet comprising a thermoplastic resin filled mat of glass fibre strands is described.
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