| 摘要 |
The present invention relates to a method for preventing the shrinkage of a pipe before a sheath pipe for a heat insulation pipe is cut while preventing the deformation of a cut surface, and to a device for executing the method. The present invention can prevent the cut surface of the pipe from being bent inwardly and deformed while reducing the shrinkage of the pipe. The method, which is for reducing the shrinkage of the polyethylene sheath pipe for a double heat insulation pipe and preventing the cut surface, includes the steps of: preparing the pipe by molten polyethylene; spraying water to the extruded pipe from a cooler and cooling the pipe; executing a corona process to treat the inside of the pipe being pulled after being cooled through using a corona discharger; and raising the outer temperature of the pipe in an unwinding apparatus to cut the pipe. |
