| 摘要 |
To provide a foamed plastic provided with holes having a specified area at a specified aperture ratio. The holes are either a through-hole or a non-through-hole and properly provided. The foamed plastic is superior in sound absorbing property and has a strength. In the case of non-through-holes, the foamed plastic can beep a sound absorbing effect as well as a sound intercepting effect, and for example, when used as a cushioning material of collision to be used as the lower portion of a dash panel of a motorear, not only the cushioning of collision but also the absorption of noises from an engine can be achieved. On the other hand, a foamed plastic obtained by pre-foaming foamable beads and again foaming the pre-foamed beads is a foamed plastic having gas permeability, which is different from usual foamed plastics. In this case, when an air current resistance value is set within a specified range, an audible sound of a human being can be most effectively absorbed. Thus, the latter foamed plastic can also be used as a cushioning material of collision and the like similar to the former foamed plastic.
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