The Foaming Process and the Damping Capacity and Sound Insulation of Bell Structures

The forming process and the characteristics of bell structures produced using batch-type foaming with a supercritical-fluid blowing agent were examined. Various forming methods were tried for the production of bell structures. Impact and acoustic tests of the structures were conducted, followed by an evaluation of shock absorption and sound insulation. Bell structures, including various kinds of ball, were successfully produced by means of batch foaming. It was verified that these bell structures exhibit the required shock absorption and sound insulation performance.