摘要 |
A composite structure, such as a structural member (12), is formed by the steps of knitting a three dimensional pre-form (17) from one or more selected fibres such as natural fibres selected from hemp, cotton, flax, jute and synthetic fibres such as boron aramide fibres, carbon fibres, glass fibres and polymer based fibres, using a three dimensional knitting machine (16). The pre-form (17) has a shape commensurate with that of the structure (12) to be formed. The pre-form (17) is caused to take its three dimensional shape by inflating or otherwise expanding the pre-form such as by injecting a foamable synthetic plastics material into the interior of the pre-form, and thereafter fixing the shape of the shaped fibres to form the composite structure. |