| 摘要 |
PROBLEM TO BE SOLVED: To provide a polystyrene plate-shaped foam or the like in which curling is suppressed.SOLUTION: There is provided a plate-shaped foam which is formed by extrusion foaming a polystyrene-based resin with a foaming agent from a circular die 100 to form a cylindrical foam 200 and then pressing the foam 200 to heat-seal the inner surface of the foam 200, where the entire density is 0.035 to 0.110 g/cm, the surface layer density of the region to 0.2 mm from the outer surface is 0.080 to 0.300 g/cmand the density difference of the surface layer density between both surface sides is less than 0.010 g/cm.SELECTED DRAWING: Figure 1 |
