| 摘要 |
PURPOSE:To readily obtain a pipe with a heat-insulating tube useful as water pipe or warm water pipe, having excellent heat insulating properties and piping operation efficiency, by packing a fomable blend containing a glassy mineral into space between specific end control members and a pipe and expanding under heating. CONSTITUTION:A separable outer mold 20 comprising a split-cavity mold 21, etc., is externally engaged with a pipe 10 of ceramic, etc., having formed unevenness on the outer periphery. Then a pair of end control members 30, slidable in the shaft direction, having alumina paper 31 attached to the opposing inner end faces, are engaged between the pipe 10 and the outer mold 20 at a desired interval to give a calcining mold. Then the outer mold 20 of the calcining mold is charged with a fomable blend of 100pts.wt. glassy mineral such as silas, 0.7-2pts.wt. blowing agent such as SiC and 0.1-0.5pt.wt. V2O5, fed to a calcining furnace and heated at 1,135-1,140 deg.C for about 30min to expand the blowing agent. Then, the calcining mold is taken out, gradually cooled, the outer mold is disjointed, the end control members 30 are taken out to form a pipe with a heat-insulating tube having the pipe integrated with the heat-insulating tube 10 of the foam. |
