| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and apparatus for manufacturing a thermally expansible synthetic resin pipe, capable of obtaining the thermally expansible synthetic resin pipe uniform in expansion speed or expansion force and also having a high expansion ratio in a low temperature region and capable of certainly applying lining to the inner surface of a metal pipe. SOLUTION: In a method for manufacturing the thermally expansible synthetic resin pipe by cooling the synthetic resin pipe 13 continuously extruded into a cylindrical shape from an extrusion mold 12 and reducing the diameter of the synthetic resin pipe 13 by a mold 15 to impart thermal expansibility to the synthetic resin pipe 13 in the diameter direction of the pipe, the synthetic resin pipe 13 is internally evacuated through the extrusion mold 12 and the inner surface of the synthetic resin pipe 13 after extrusion is cooled by the atmosphere sucked from the leading end opening of the synthetic resin pipe 13 and, thereafter, the diameter of the pipe is reduced by the mold 15.
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