| 摘要 |
PROBLEM TO BE SOLVED: To enable forming of a thermoplastic resin pipe in a uniform coat thickness along the intrapipe wall in the existing piping by introducing a cylindrical braid made up of a thermoplastic resin fiber yarn through piping, then expanding the diameter of the introduced braid and thermally melting the diametrally expanded braid to be set into a tubular film. SOLUTION: A braid 1 obtained by knitting a polyethylene resin yarn into a cylindrical shape is introduced through piping 3, and is diametrally expanded along the in-pipe wall 4 of the existing piping 2 after introduction. A teflon film tube 5 with flexible stretchability and airtightness and a higher melt point than polyethylene resin, is introduced through the interior of the diametrally expanded braid 1. Further, a high temperature hot blast at an intermediate temperature level between the melt point of the polyethylene resin and that of the teflon film tube 5, is blown under pressure into the inside of the teflon film tube 5 to thermally melt the diametrally expanded braid 1. Thus the tubular coat of the polyethylene resin is formed along the in-pipe wall 4. After that, the tubular coat is set by air-cooling into a polyethylene resin pipe. |
