METHOD FOR MANUFACTURING SYNTHETIC RESIN PIPE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a synthetic resin pipe excellent in dimensional stability and roundness without generating a stripe or the like on the outer peripheral surface of the synthetic resin pipe. SOLUTION: In the method for manufacturing the synthetic resin pipe by passing the synthetic resin pipe, which is extruded from the cap of an extruder in a molten state, through a cooling water tank while shaping the molten resin pipe by a sizing die to cool the same, a shaping die is arranged to the leading end part of the sizing die and hot water is circulated to the cavity formed in the shaping die to heat the shaping die and allowing a part of hot water to flow out from the inner peripheral surface of the shaping die to form a water film between the outer peripheral surface of the synthetic resin pipe and the inner peripheral surface of the shaping die when the synthetic resin pipe is passed through the shaping die.