Low density foaming of poly(ethylene-co-octene) by injection molding

Low density poly(ethylene-co-octene) foams were produced by injection molding compounded formulations consisting of resin, chemical foaming agent, activators, cross-linking agent and nucleating agent. The effect of the formulation on the foam density and morphology was examined for one set of processing conditions. The concentration of cross-linking agent must be geared to the initial resin viscosity to allow proper bubble growth. The foam will otherwise collapse or show little expansion. The results show that an optimized formulation along with proper processing conditions yield fine-cell foam of low density.