| 摘要 |
A synthetic resin porous pipe having inner and outer wall reinforcing layers is provided to form inner and outer wall reinforcing layers having a predetermined thickness on inner and outer walls of the synthetic resin porous pipe. Inner and outer wall reinforcing layers(200,300) are formed in a synthetic resin porous pipe. A wall structure(110) of the synthetic resin porous pipe is selected, and the inner and outer wall reinforcing layers are integrally formed on the inner and outer walls of the wall structure. The inner and outer reinforcing layers serve as a sub function with respect to the synthetic resin porous pipe. The inner and outer reinforcing layers have desired thicknesses according to inner and outer diameters of the synthetic resin porous pipe. A space(120) of the wall structure is twisted when the synthetic resin porous pipe is extrusion-molded.
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