Abstract: The invention relates to the field of forming fibrous structures. A fibrous structure according to the invention has an upper group of fibrous layers and lower group of fibrous layers subjacent the upper group of fibrous layers. A multitude of Z-fiber bundles cohere the fibrous layers, each fibrous layer within the upper group of fibrous layers having a portion of the multitude of Z-fiber bundles originating in that fibrous layer and passing through a number of fibrous layers disposed beneath that fibrous layer without passing through all of the fibrous layers disposed beneath that fibrous layer. The number of fibrous layers penetrated by the Z-fiber bundles is constant within the first portion.

Abstract: The invention relates to the field of needling processes for forming fibrous preform structures. The invention is particularly useful in forming fibrous preform structures suitable for subsequent processing into high temperature resistant composite structures such as carbon/carbon aircraft brake disks. The process according to the invention compensates for fiber pull back induced by fiber resilience, and for compaction in previously needled layers induced during subsequent needling passes. According to a further aspect of the invention, Z-fiber distribution throughout the thickness of the fibrous preform structure may be manipulated as necessary to achieve a desired distribution.

Abstract: Fibrous substrates for the production of carbon and/or ceramic (including mixtures of these) fiber reinforced carbon and/or ceramic (including mixtures of these) composites and to methods of manufacture of same. A shaped fibrous structure comprising at least a first fibrous tape layer of a width generally corresponding to that of the fibrous structure to be formed, the first fibrous tape layer superposed upon and joined to least one other fibrous layer by needlepunching to produce cross-linking of the layers by fibers displaced out of the layers and extending in a direction generally perpendicular to the faces of the layers, and methods of making same.