Two designs of polyethylene (PE) foam cushions were compared, using a rigid 'product' of mass 5.6 kg, and an outer corrugated fibreboard box. The acceleration-time history for the product was measured when the box was dropped flat from 1 m onto a rigid floor. The data was processed to calculate the impact force as a function of the packaging deformation. Finite element analysis (FEA) predictions of the impact force vs. package deflection were accurate for end-cap designs using Ethafoam, but underestimated the slope of the experimental force vs. deflection relation for corner-cap designs. The corner-cap design is more efficient in reducing the peak product acceleration for multiple impacts. The contribution of the corrugated board box to the impact response appears to be small. The FEA results were compared with those from the cushion curve design method and were found to better predict the performance of complex shaped cushions.

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A regular Kelvin foam model was used to predict the linear thermal expansion coefficient and bulk modulus of crosslinked, closed‐cell, low‐density polyethylene (LDPE) foams from the polymer and gas properties. The materials used for the experimental measurements were crosslinked, had a uniform cell size, and were nearly isotropic. Young's modulus of biaxially oriented polyethylene was used for modeling the cell faces. The model underestimated the foam linear thermal expansion coefficient because it assumed that the cell faces were flat. However, scanning electron microscopy showed that some cell faces were crumpled as a result of foam processing. The measured bulk modulus, which was considerably smaller than the theoretical value, was used to estimate the linear thermal expansion coefficient of the LDPE foams. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3741–3749, 2004