HERSTELLUNGSVERFAHREN EINES ROHRES MIT VERBESSERTER STRUKTUR

摘要

A plastic pipe of an improved construction such that the pipe has apertures formed therein when the pipe is viewed in cross section, the pipe being made by a process including extruding a hot plastic flow through a die head (17) having a plurality of first sized gaps and second sized gaps, the second sized gaps having an aperture located inside each gap. A die (15) is secured to a manifold assembly (10), with the manifold assembly (10) having sets of tubes located centrally of one another, each set of tubes including a water inlet tube (150), a tube through which a vacuum is pulled (140) and a water return tube (130). Each set of tubes is positioned longitudinally within a respective die manifold tube (165) which extends through the die (15).