Preparation and characterization of multilayer foamed composite by rotational molding

A multilayer material was produced by rotational molding to study the effect of composition on the mechanical behavior of a cylindrical liquid container. The first (outer) layer was a composite of linear medium density polyethylene (LMDPE) with 5, 10, or 15 wt% agave fiber (AF). The core (middle) layer was foamed LMDPE with different amount of foaming agent (0, 0.15, 0.25, 0.5, and 0.75 wt%). Finally, the third (internal) layer was neat LMDPE. This structure was produced to optimize the mechanical properties of the molded parts while decreasing weight with good surface properties. From the morphological analysis, it was observed that the layers are not always well defined because of gas migration, especially from the foamed core to the composite layer. As expected, density increased with fiber content while decreasing with foaming agent concentration. In general, impact strength (Charpy and Gardner) was directly related to the overall density of the part. POLYM. ENG. SCI., 2015. © 2015 Society of Plastics Engineers