Method for making composite pipes with high mechanical and tribologic characteristics

摘要

Prodn. of a tube of composite material from a tissue of reinforcing fibres and a sheet of matrix material, both available on feed rolls, comprises: (1) preheating a mandrel; (2) fixing the tissue and sheet on the mandrel; (3) rotating th mandrel to wind on th tissue and sheet under tension; (4) continuing winding while heating the composite material and cooling the mandrel until the desired tube dia. has been attained; (5) stopping th heating and rotation; (6) stopping the cooling when the mandrel has reached its preheat temp.; and (7) removing the mandrel. Also claimed is a machine for making a tube as above, comprising a support structure with two mountings between which the mandrel (10) is placed so as to be rotatable by a drive unit, where the mandrel has slits for attaching the tissue and sheet; feed rolls (20,22) for maintaining the tissue and sheet under tension while they are wound onto the mandrel; and a heater (16) located in a welding zone between the (incoming) tissue and sheet. Also claimed is a composite material produced on the basis of the simultaneous winding of (a) a tissue of reinforcing fibres comprising naked fibres impregnated with a polymer and (b) a sheet of matrix material comprising the same polymer and an additive.