| 摘要 |
PURPOSE:To enable mass production with low cost by aggregating narrow plates such as lumbers for thinning and filling a core material with reinforcing plastic or the like or glueing the core material to the reinforcing plastic to unify them. CONSTITUTION:Inside materials 1-5, 1-6 and outside materials 1-2, 1-3 are prepared by aggregating and laminating narrow plates and a core material 1-4 molded of reinforcing plastic or the like is stuck or injected between both side materials to unify them. Next, a top rail 1-1 is dowel jointed with the side wall material of a bathtub. The surface of the bathtub is subjected to the treatment of fluororesin. Thus, mass production is enabled with cost reduction and the bathtub is prevented from stains and slippery condition to improve a heat retaining property even if cleaning is little carried out. |
