Abstract: Duplex layers of carbon fiber each comprising a lower portion of uni-directional filaments and an upper staple fiber portion are laid one on top of the other in an annular form. Needles are reciprocated through the layers to cause the staple fiber 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 fiber 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 fibers may be added to the stop of the stack and needled in order to enrich the upper layers with interconnecting staple fibers, which upper layers would otherwise be deficient in interconnecting staple fiber.

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 fibres.

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: A succession of fibrous sheet segments (10) are supplied from a rotary magazine (12) to a rotating bowl (14). Segments are added to the bowl with their adjacent radial edges abutting each other and are passed beneath a reciprocating needle board (20), whereby filaments from the segments in upper layers are displaced into segments in lower layers to bind the segments together and form a self-supporting preform. Two needle heads (22) are able to move up and down and rotate in order to pick up a segment from the store and deposit that segment on the bowl. A few barbed needles (22A) pick up the segment and more grooved needles (22B) push through fibre to tack the segments down. A conical roller (28) bears against the top of the segments after they leave the needle board to bear against the preform to compress the fibres and also to provide a monitor of the distance between the needle board or the mounting block and the top layer of the preform.

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: 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.