Dunlop Gmbh

Dunlop Limited a British Company

Keith A Williams

Ronald Fisher

Maurice J Evans

At least one layer of fibers of a material susceptible to heating by electromagnetic radiation is incorporated in a porous structure. The structure is subjected to the radiation to heat up the body which is contacted with hydrocarbon gas to cause the gas to deposit carbon within the porous structure and thereby cause densification.

Densification of a porous structure (II)

A method for the densification of a porous structure comprises providing the structure with a body of material (,) which includes a susceptor element foil (,) which is more susceptible to heating by electromagnetic radiation than the other material (,) of the body, exposing said porous structure to hydrocarbon gas and simultaneously applying an electromagnetic field to said porous structure whereby said susceptor element (,) at least in part causes heating of the porous structure to a temperature at which the gas infiltrating the porous structure deposits carbon within the porous structure.

Densification of a porous structure

A method for the densification of an annular body having a porous structure and comprising layers of fabric, which includes locating a susceptor element within the porous body, the amount of the susceptor element occupying less than 5% of the volume of the porous body, the susceptor element being in the form of a layer comprising one of a foil and a fiber and having plural holes therein through which adjacent layers of fabric of the porous body contact each other, said susceptor element being made of a material which is more susceptible to heating by electromagnetic radiation than the material of the porous body, and exposing the porous body to hydrocarbon gas and simultaneously applying an electromagnetic field to the porous body, the susceptor element within the porous body at least in part causing heating of the porous body to a temperature at which the gas infiltrating the porous body deposits carbon within the porous body.

Densification of a porous structure (III)

In a method of making a carbon fibre preform such as for use in the manufacture of a friction disc a compressible body of carbon fibre or carbon fibre precursor material is acted upon by compressing means to compress the body to a required thickness and then operated upon by means such as a barbed needle-punch needle for a stitching thread which penetrates substantially the whole thickness of the body whereby the compressed preform may be removed from action by the compressing means in a free-standing and compressed state. If the method uses carbon fibre precursor material, that is then subjected to carbonization.

Manufacture of carbon fibre preform

Method of fabricating a multi-ply carbon fibre fabric, preform or composite material from a layer of unidirectionally aligned carbon fibres of ultra-high modulus and a layer of low modulus carbon fibre comprising the steps of: arranging in superimposed relationship the layer of unidirectionally aligned carbon fibres of ultra-high modulus and the layer of low modulus carbon fibres so that at least a substantial number of the fibres of low modulus are disposed transversely of the fibres of the ultra-high modulus fibre layer, and connecting the two layers by interlacing fibres of the layer of low modulus fibres with those of the layer of ultra-high modulus fibres by needle-punching using felting needles orientated and configured so that their barbs snag only the low modulus fibres during passage through the layers.

Ultra-high performance carbon composites

A sheet of parallel carbon or carbon-precursor filaments is supported by a carrier sheet of fugitive backing material and needle punched. The fugitive backing material is subsequently destroyed leaving displaced or broken portions of the filaments entangled together to provide a stable sheet for composite manufacture, particularly for reinforcement of a carbon-carbon composite.

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Coventry, United Kingdom

Keith A Williams