Title:
【発明の名称】中空プラスチック部材の溶融接合方法
Document Type and Number:
Japanese Patent JP3261531
Kind Code:
B2
Abstract:
Members such as natural gas distribution pipes (10, 12) of polyethylene or other plastics material are assembled with an internal liner (14) and heat is applied to the pipes externally by an electric heater assembly (18). After cooling the heater assembly is removed. The outer surface of the liner (14) fuses and bonds to the insides of the pipes. The pipe end portions fuse and bond across the interface (30). The liner is for example of polyethylene of molecular weight more than half a million containing finely divided carbon as filler. The liner is extruded and cold drawn to reduce its diameter to a close fit in the pipes. The applied heat causes the liner to expand more than the pipes. The liner retains enough stiffness to press against the insides of the pipes. Melt pressure and flow result and serrations on the liner give interlocking in the bond interface. The liner causes pressure drop in gas flow no greater than internal bead in butt fusion joining.
Inventors:
Stafford Trevor George
Application Number:
JP51581590A
Publication Date:
March 04, 2002
Filing Date:
November 21, 1990
Export Citation:
Assignee:
Lattice Intellectual Property Limited
International Classes:
B29B13/02; B29C65/00; B29C65/14; B29C65/02; B29C65/18; B29C65/34; B29C65/36; B29C65/68; B29L22/00; (IPC1-7): B29C65/68; B29C65/02; B29L22:00
Domestic Patent References:
| JP5085678A | ||||
| JP60232932A | ||||
| JP56118A | ||||
| JP1133719A | ||||
| JP63503158A |
Attorney, Agent or Firm:
Minoru Nakamura (9 outside)
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