アクリル樹脂発泡フィルムによる衝撃低減の効果

抄録

Impact forces applying to a thin acrylic foam film on the end of a bar were measured to clarify relation between thickness of the film and effect of impact reduction: decreasing impact force and impact energy absorption by using a manufactured falling ball testing machine. The specimens were the acrylic foam films having thicknesses of 700 to 200 µm and density of 0.50 to 0.30 mg/mm³ on a polyethylene terephthalate substrate film with a thickness of 38 µm. A stainless steel sphere with a diameter of 19 mm was dropped onto the specimen on the flat end of a steel bar. The impact loads were measured from the strain histories of the steel bar. The maximum impact force for the foam film of mere 200 µm thick was 50% smaller than the one for no foam film. As the results, logarithmic values of the maximum impact loads were found to be reduced relative to the film thicknesses and the durations of the loads were also found to be proportional to the thicknesses. The absorbed impact energy of the foam films was calculated by the impulses of the impact loads. The acrylic foam film absorbed approximately whole potential energy of the ball. Therefore, the thin acrylic foam films were found to be effective in the reduction of impact load and absorption of impact energy.