| 摘要 |
PURPOSE:To prevent a crack and damage of a foamed sheet, by a method wherein sticking is performed uniformly by eliminating a bulging phenomenon wherein air and a solvent are accumulated and a closed-cell is not destroyed by boring holes, whose distance between the holes and a hole diameter are specified, on a closed-cell foamed sheet. CONSTITUTION:As for a closed-cell foamed sheet 11, holes 12 are bored at predetermined intervals beforehand. As for this boring method, a large number of needles is provided on the circumferential surface of a revolving roll at necessary intervals, the revolving roll is made to revolve and the holes are bored by piercing the needle into the foamed sheet. As for the size of the hole, the diameter is made into 0.1-2.0mm by converting the hole into a perfect round. As for a distance between the holes 2.0-100mm in distance is selected. As for arrangement of the holes 12, though it is not limited specifically, it is desirable to provide them at zigzag intervals. The title sheet having holes falling within a range like this does not generate bulges by freeing outside air and a solvent of the inside of a bubble of the foamed sheet, adheres sufficiently to a metal plate and does not spoil heat insulation properties of the foamed sheet 11. |
