Foam rotational molding of hybrid polyethylene nanocomposites: synergistic effect of microtalc and nanoclay

Rotational molding is a process used to produce seamless, one-piece, and hollow polymeric parts. Foam rotational molding has recently become an increasingly important process in the foam industry. However, foam rotational molding is still a challenging process to fabricate polymeric foams. The focus of this manuscript was to assess the effect of material parameters on the foam properties of samples produced by rotational molding. Rotational molding experiments were performed on a laboratory-scale two-axis rotational machine, designed and manufactured by the authors. The effects of microtalc as nucleating agent, nanoclay as reinforcing agent, and their synergetic effect were investigated on the cell density, cell size, and expansion ratio of hybrid microtalc/nanoclay polyethylene nanocomposites. The cell density was improved by 96% and 89% by addition of 1 wt% of microtalc and nanoclay, respectively, compared to pure polyethylene foams. The cell size was reduced by 20% and 17.5% in 1 wt% of microtalc and nanoclay, respectively. However, the synergetic effect of using both microtalc and nanoclay at 1 wt% was more significant compared to their individual effects. The cell density was enhanced by 313% and the cell size was decreased by 35% compared to pure samples.