摘要 |
An apparatus for producing spirally wound thermoplastic pipe. The apparatus has a helical track and a series of independent moldblocks that run in the track to provide a mandrel surface that rotates and advances axially. A band of thermoplastic material is extruded onto the mandrel surface and wound on the surface in an overlapping helix. The apparatus is equipped with a moldblock return mechanism that receives blocks from the downstream end of the track and returns them to the upstream end, so that unlimited lengths of pipe can be produced. |