MANUFACTURING METHOD FOR LARGE CALIBER THICK-WALLED POLYETHYLENE PIPE

摘要

PPROBLEM TO BE SOLVED: To provide a method for manufacturing a large caliber thick-walled polyethylene pipe having uniform strength without causing the resin sag from the inner surface of the pipe or the cross-sectional flattening deformation of the pipe. PSOLUTION: The outside surface of the formed and solidified polyethylene pipe P1 is preliminarily heated and melted, and molten polyethylene is annularly extruded from the discharge cap 10 of an extruder 3 to coat the heated and melted outside surface of the polyethylene pipe P1 and integrally welded to the outside surface of the polyethylene pipe P1 to form a thick-walled polyethylene pipe P. It is more suitable to evacuate the space formed before the molten surface of the polyethylene pipe P1 and discharged molten polyethylene are closely bonded. PCOPYRIGHT: (C)2005,JPO&NCIPI