| 摘要 |
PROBLEM TO BE SOLVED: To obviate a large preservation place and to transport efficiently by molding a thermoplastic resin sheet into an open pipe and fusion-bonding the opposite edges of the pipe. SOLUTION: A thermoplastic resin sheet 1 is wound onto a metal tube having an outside diameter nearly equal to the inside diameter of a target resin pipe and molded into an open pipe 2. Heating wires are inserted into the opposite edges 3 of the pipe 2, and the edges 3 are fusion-bonded by current-passing/ heating to obtain a thermoplastic resin pipe 4. Since the resin sheets can be preserved in the form of sheets, a large place for the preservation is unnecessary, and a large amount of the sheets can be transported at a time. The molding of the thin open pipe can be implemented on the construction site by winding the sheet onto a metal tube or by using a simple roll molding machine. For the thick pipe, an apparatus for heating the metal tube and the resin sheet is used. |
