Mechanical Behaviour at Low Strains of LDPE Foams with Cell Sizes in the Microcellular Range: Advantages of Using these Materials in Structural Elements.

Abstract

This paper presents the production method and the compressive mechanical response at low strains for a collection of polyethylene foams with high densities and cell sizes in the microcellular range. The materials were produced using a modified compression moulding technique that allows and independent control of density and cell size. The materials had a relative density between 0.27 and 0.92, an homogeneous and multi-structured cellular structure with dense skin and foamed core and cell sizes in the range 30 to 100 microns. The YoungŽs modulus was reduced when density did. For relative densities higher than 0.7, the reduced Young¿s modulus of the foams was higher than that of the solid. In addition, it has been proved that variations in the cell size at constant density did not influence the Young¿s modulus. The advantages of using these materials for the production of plastic pipes have been analysed. A reduction of the weight of pipes loaded in compression of up to 42 % can be reached by using these foams in spite of the solid material from which the foam was produced