Method for manufacturing a multi-layer plastic pipe

摘要

A multi-layered plastic pipe particularly suitable for use as an intake manifold of an internal combustion engine is provided. The present pipe includes a hollow plastic core, at least one spacer member provided on the hollow plastic core and an outer layer integrally provided on the outer peripheral surface of the hollow plastic core excepting the spacer member. The spacer member is preferably formed from a plastic material, and the outer layer is also formed from a plastic material. There is also provided a method for manufacturing a multi-layered plastic pipe using a spacer member to prevent a hollow plastic core placed in a mold cavity from being deformed when a molted plastic material is supplied into the mold cavity under pressure.