| Although the shock performance of cushioning material is determined by testing rectangular blocks with a square base, it is unlikely that the same shapes will be used in packaging fabrication. As the shock performance of a cushion may vary according to cushion/product configuration, experiments were carried out to investigate the effects on shock transmission of (A) tapered angles of cushion blocks and (B) position of impact on the cushion block. A Lansmont cushion tester was used to simulate impact forces that a cushion package encounters during handling. For part A, trapezoidal blocks of expanded polyethylene (EPE) cushions with four different tapered angles (15°, 30°, 45°, and 60°) and a rectangular cushion block with a square base as control, all having same volume with fixed thickness and width, were used. For part B, five different impact positions were used.; Results of part A of this study showed that the effective area used to distribute shock by trapezoidal cushion blocks was different from the area used by the control cushion block. Results of part B of this study showed that the area of the cushion used to distribute shock increased as the position of impact moved towards the center of the cushion block. These results have considerable relevance in designing the effective area of the cushion block to achieve desired shock performance of the package. |
