Polyethylene-Kevlar Composite Foams III: Torsion Properties

Abstract

High density closed-cell Kevlar-polyethylene composite foams (17 - 30% void fraction) were prepared by compression molding and characterized via torsion rectangular tests in order to determine the effect of thin unfoamed skins and Kevlar content on shear modulus. It was found that structural foam models gave better results than uniform foam models indicating that thin skins have an important effect on the shear modulus of polymer foams. The normalized modulus of our composite structural foams can be predicted by a sandwich model in combination with Berlin's approach and Rosen's model for the aspect ratio of the fibres.