Polyethylene Foams Produced under a Temperature Gradient with Expancel and Blends Thereof

Thermoplastic polymer foams can be produced using expandable beads like Expancel microbeads. In this work, density graded polyethylene foams were produced by imposing a temperature gradient using compression moulding. This was done by controlling independently the top and bottom plates of the mould at different temperatures. Foaming was done by using different grades of Expancel and blends of them to produce a complex cellular morphology. In this work, a complete morphology in terms of cell size and cell density will be presented in relation with density profile across the foam thickness. The foam behaviour under different types of mechanical loadings will also be discussed.