Method and apparatus for manufacturing a composite tape shaped from reinforcing fibres and thermoplastic material

摘要

A rotationally formed container whose wall has continuous inner and outer zones are made of the same thermoplastic. Part of the second zone away from the outer wall surface also has glass fiber reinforcement helically wound along the longitudinal rotational axis of the container. The wall has a vacuum volume proportion≤0.5 %. Independent claims are included for the following: (a) A length of piping as above. (b) Manufacturing a container as above by helically winding a heated ribbon of glass fiber reinforced thermoplastic onto a mandrel. The ribbon is heated to above the fusion temperature of the thermoplastic in a first zone just downstream of where it contacts the mandrel. Pressure is applied in a second zone just downstream of the first zone. (c) Apparatus for performing (b). Preferred Features: The wall has a vacuum volume proportion≤0.2 %. The ribbon is formed by impregnating a glass fiber fabric that has been heated to between the fusion temperature and degrading temperature of the thermoplastic and then further heating it to maintain this temperature. The fibers in the fabric are parallel. The ribbon is wound so the fibers lie at 50 - 55 degrees to the pipe axis. The ribbon is softened by heating before it is applied to the mandrel.