Abstract: Duplex layers of carbon fibre each comprising a lower portion of uni-directional filaments and an upper staple fibre portion are laid one on top of the other in an annular form. Needles are reciprocated through the layers to cause the staple fibre to be pushed downwardly to interconnect the layers. The base supporting the layers being assembled is gradually lowered until there comes a time when the bottom of the needle stroke no longer passes through all of the layers. At that time additional layers comprising staple fibre only are added and needled down into the stack to enrich the lower layers. After that enrichment the stack is then built up by adding further duplex layers. When all of the duplex layers have been added, further staple fibres may be added to the stop of the stack and needled in order to enrich the upper layers with interconnecting staple fibres, which upper layers would otherwise be deficient in interconnecting staple fibre.

Abstract: A method of producing a shaped fibrous fabric structure is similar to that described in the parent application, in that a continuous filament sheet is subjected to a needle punching action, segments are cut from the sheet and these segments are assembled to form an annulus, and then subjected to rotary motion under a reciprocating needling head and continuing to add segments to build up a stack of layers whilst at the same time continuing the needling action, and lowering the base of the stack relatively to the needling head. However, in a final step, one or more layers of segments are added to the top of the stack, and these are needled into the stack without lowering the stack. Furthermore, these additional layers are preferably made entirely of stapled fibers.

Abstract: The invention is concerned with a method and apparatus for producing a shaped filamentary structure and more particularly, to filamentary structures which can be subjected to further processing to produce a carbon-carbon product. A specific use of the invention is in the production of discs for use in aircraft braking systems.The method includes needle punching a unidirectional layer of filaments to give a degree of dimensional stability; cutting a plurality of segments from the layer of needle punched filamentary material; assembling a plurality of segments in side-by-side contiguous relationship to produce a filamentary layer of the required structural shape; superimposing at least one similar layer on the first layer and needle punching the assembled layers to produce cross-linking of the layers.

Abstract: In pressing wet concrete between a ram and a mold to compact the concrete and express water from it so as to produce a molded slab, a layer of filter material is provided between the ram or the base of the mold and the concrete and the filter material is secured by a discontinuous coat of adhesive applied as a transfer to the ram and/or to the base of the mold. The adhesive is applied over a sufficient area of the filter material to secure adhesion of the filter material to the ram or base of the mold. The discontinuous adhesive coating is provided as a pattern of particles which covers substantially the entire area of the face of the filter and is present over between 2% and 15% of the total surface area of the filter material.

Abstract: The invention is concerned with a method and apparatus for producing a shaped filamentary structure and more particularly, to filamentary structures which can be subjected to further processing to produce a carbon-carbon product. A specific use of the invention is in the production of discs for use in aircraft braking systems.The method includes needle punching a unidirectional layer of filaments to give a degree of dimensional stability; cutting a plurality of segments from the layer of needle punched filamentary material; assembling a plurality of segments in side-by-side contiguous relationship to produce a filamentary layer of the required structural shape; superimposing at least one similar layer on the first layer and needle punching the assembled layers to produce cross-linking of the layers.

Abstract: A method of producing a shaped fibrous fabric structure is similar to that described in the parent application, in that a continuous filament sheet is subjected to a needle punching action, segments are cut from the sheet and these segments are assembled to form an annulus, and then subjected to rotary motion under a reciprocating needling head and continuing to add segments to build up a stack of layers while at the same time continuing the needling action, and lowering the base of the stack relatively to the needling head. However, in a final step, one or more layers of segments are added to the top of the stack, and these are needled into the stack without lowering the stack. Furthermore, these additional layers are preferably made entirely of stapled fibers.

Abstract: The invention is concerned with apparatus for producing a shaped filamentary structure and more particularly, a filamentary structure which can be subjected to further processing to produce a carbon-carbon product. A specific use of the invention is in the production of discs for use in aircraft braking systems. The invention comprises an apparatus comprising an open-topped receptable for assembled segments formed by cutting a plurality of segments from a layer of needle punched filamentary material; a needling head located over only part of the receptacle; means for rotating the receptacle to bring a complete annulus of the filamentary segments in it under the needling head and a support located inside the receptacle and means for rotating the support with the receptacle, and lowering the support relatively to the receptacle during the needling operation.