摘要 |
Reinforced composite materials having a thermoplastic matrix and at least 30% by volume and preferably at least 35% by volume of reinforcing filaments, at least 25% by volume being pitch based graphite fibres, are produced having a longitudinal flexural modulus according to ASTM D790-81 of at least 250 GN/m<2>. Impregnation of very fragile, inflexible pitch based graphite filaments is achieved using supporting filaments of greater robustness to the abrasion encountered in impregnation processes and, optionally, severing the filaments during the process if products containing only pitch based graphite filaments are required. |