Due to the centrifugal forces the materials are pressed against the wall of the mould under enormous pressure (in the order of 40G) and the compound materials are compacted and de-aerated completely. This manufacturing technology assures the production of pipes with high density walls free of voids and evenly smooth surface all over their length. The curing of the pipes proceeds in the rotating mould, so that an exact roundness with constant wall thickness over the whole length of the pipe is guaranteed.