Cushioning and Load Distribution Performance of Plastic Foams

Cushioning and load distribution performance of plastic foams was investigated, using a human faceform as the loading object. A technique for measuring contact surface between faceform and plastic foam was developed. Transferrable paint applied to the foam facilitated determination of average stress over its surface, which in turn was employed to evaluate load distribution properties of the foam. Impact and static testing results on several plastic foams were analyzed. It was found that a good cushioning material characterized by low peak deceleration might show high average stress, thus making it an inefficient load distributor.

The faceform used in the study incorporates the effect of face geometry during loading and thus provides a realistic simulation. Variation of material response with loading geometry and possible correlation between load distributing properties and rigidity of the foam are also discussed.