Patent Number: 6,251,332

Title: Method for manufacturing a multilayer plastic pipe

Abstract: A method for manufacturing a multilayered plastic pipe particularly suitable for use as an intake manifold of an internal combustion engine is provided. The method includes the steps of forming a hollow plastic core, providing at least one spacer member on the hollow plastic core, supplying a molten plastic material into a mold cavity and applying a compression force to the material inside the cavity to form an outer layer integrally on the outer peripheral surface of the hollow plastic core. The spacer member prevents the hollow plastic core in the mold cavity from being deformed when a molten plastic material is supplied into the mold cavity under pressure.

Inventors: Nakagawa; Tatsuya (Matsudo, JP), Ezaki; Yasuo (Nitta-machi, JP)

Assignee: Excell Corporation

International Classification: B29C 33/00 (20060101); B29C 33/12 (20060101); B29C 45/56 (20060101); B29C 45/14 (20060101); B29C 70/00 (20060101); B29C 70/08 (20060101); B29D 23/00 (20060101); B29C 70/72 (20060101); F02M 35/10 (20060101); F02M 35/104 (20060101); F16L 9/133 (20060101); F16L 9/00 (20060101); B29C 49/04 (20060101); B29C 045/16 (); B29C 049/00 ()

Expiration Date: 06/26/2018