Fibre reinforced blade

M. Bedwell o f Morgan Crucible Ltd s made some general points on the philosophy o f CFRP. He said that it is in the sobering applications that the real future o f carbon fibre lies. The importance o f not taking cost effectiveness o f a material as the ultimate decision o f whether or not to use it was stressed. In the discussion, he was asked why the price o f Morgan's fibre was higher than a n y b o d y else's. He replied, "All we want is the good e n o u g h - and it so happens that our good enough is a bit better than anyone else's good enough." The conference was extremely well run, and the discussion was lively and interesting. Most o f the speakers assumed that their papers had already been read and restricted their talks to design or materials philosophy.

Readers interested in any o f the papers discussed in this report are advised to contact the Production Engineers Research Association for copies.

REFERENCES 1 Locke, H. B., 'The opportunities of fibre technology', Fibre

technology in Engineering, April 1970 2 McMullen, P. L., 'Fibre reinforced materials', Fibre technology in

Engineering, April 1970 3 Bowen, D. H., 'The potentialities of carbon fibre', Fibre

technology in Engineering, April 1970 4 Tovey, H. J., 'Fibre technology at Bonas Brothers', Weavematic Looms Ltd, Fibre technology in Engineering, April 1970 5 BedweU, M., 'Fibre technology at Morgan Crucible Ltd' Fibre

technology in Engineering, April 1970

Pa ten t surve y Carbonaceous fibers and the manufacture thereof Accontius, O. E. UK Patent Specifica-

,o,,s_,o,c,,,o

reaction vessels can be wound, the composite having high strength at elevated temperatures.

tion, 1,188,146 (15 April 1970) The manufacture of carbon fibres from para-polyphenylene is described. The para-polyphenylene is extruded through a die, the molecules of the fibre aligning themselves axially in the fibre. The fibres are pyrodysed in an inert atmosphere from 800 ° and above. An inert filler can be added to the powder before extrusion, graphite being specifically mentioned. Being anisotropic, the fibres display good tensile strength, elastic modulus and thermal conductivity. Improvements in or relating to pyrolytic graphite composite materials Atlantic Research Corporation UK

Patent Specification, June 1970)

1,194,907 (17

Pyrolytic graphite coated carbon fibres, in the form of a carbon strand, are spaced in a matrix of pyrolytic graphite at 0-1in intervals. The strands of each layer are unidirectionally oriented and bonding is effected with a carbonaceous gas. Pyrolysis of the gas occurs and the pyrolytic graphite matrix is nucleated from the heated strand substrate. Deposition of pyrolytic graphite envelopes the strand of fibres and achieves the bond with the matrix. Structures suitable for high temperature moulding operations and

3]4

COMPOSITESSeptember 1970

Improvements in or relating to the manufacture of composite sheets of reinforced resin

UK Patent Specification, (18 March 1970)

1,184,358

An additional coating of resin is applied to a mineral fibre reinforced resin sheet to ensure that the fibres are total encapsulated. The protective layer, of uniform thickness, is applied by using a backing strip under uniform longitudinal and transverse tension. The resin of the core reinforced layer may be of lower grade than the coating resin, due to the protection afforded by the coating layers. The composite sheet is less vulnerable to climatic and mechanical action. Novel composite structure E I Du Pont de Nemours and Co UK

Patent Specification, June 1970)

1,195,114

(17

A layer of coalesced aromatic polyimide resin is bonded to a cured Novolak phenolic resin layer, with a high shear strength bond. Particulate inert filler may be added to either layer, increasing the modulus of elasticity. Glass, asbestos or metal particles may be used. Particles at the surface of the polyimide resin layer

produce ideal friction gripping, as in clutch and brake shoe facings. The phenolic resin layer acts as a support. Another application is in the composite rim grinding wheel, silicon carbide and diamond particles being used as filters. Fibre reinforced blade Goodwin, J. R. UK Patent Specifica-

tion, 1,186,486 (2 April 1970) A fibre reinforced blade for application in a gas-turbine engine is described with a reinforcement at the leading edge. The reinforcement consists of two strips of metal, suitably shaped and joined by electron beam welding, brazing or gluing. The contour of the strips is achieved by chemical machining. After the strips are fitted, further layers of fibre reinforced material are laid on the blade, over the outside of b o t h blade core and reinforcement. Composite reinforced plastics pipe Grosh, J. L. UK Patents Specification,

1,185,677 (25 March 1970) The capability of the pipe to withstand internal and external pressure loads is the result of a particulate inclusion between adjacent turns of the reinforcing filaments. A synthetic plastics resin matrix binds the components of the wall structure together. The thickness of each zone must be carefully controlled to avoid internal