| 摘要 |
<p>PURPOSE:To obtain a compound tube furnishing an even thickness of foaming resin layer and generating small draining sound by dispersing particles of an inorganic substance in a foaming resin layer in a compound tube make by inserting an inner tube made of a synthetic resin to an outer tube made of a metal, and forming closely foaming resin layer in the clearance between the inner tube and the outer tube. CONSTITUTION:An inner tube 3 made of a synthetic resin such as polyvinyl chloride is inserted to an outer tube 2 made of a metal such as a steel, and a layer 4 made by dispersing particles of an inorganic substance such as iron or barium in a foaming resin such as an urethane system resin is formed closely in the clearance between the inner tube 3 and the outer tube 2. This compound tube 1 is obtained by rotating the inner tube 3 in which projecting lines 32 are formed on the outer wall surface in the circumferential direction, feeding a foaming resin material 8 to accumulate in recesses 34, winding a meshy belt material 6 from the outside and fixed to the inner tube 3, and heating to generate foams after inserting the inner tube 3 to the outer tube 2. As a result, the draining sound is absorbed to the foaming resin layer, hardly leaked to the outside, and residents do not feel uneasy the draining sound from the upper floors, in a housing complex and the like.</p> |
