Rotational molding of polyethylene foams has increasingly become an important process in industry because of its thicker walls, low sound transfer, high stiffness and good thermal insulation. This report is to assess the rotomoldability of multilayer polyethylene foamed parts. The polymeric material used is high-density polyethylene and the foaming agent used is endo-thermal chemical blowing agent. Two different molding methods, by powder and by pellet, were used to mold the multilayer-foamed parts. Rotational molding experiments were carried out in a laboratory scale uniaxial machine which is capable of measuring internal mold temperature in the cycle. Characterization of molded part properties has been performed after molding. The final goal of this study is to investigate how the blowing agent and processing conditions can influence the process of rotational molding and the final product quality. It was found that the rotational molding of two-layer polyethylene foams has the advantage of better impact properties as well as fine outside surfaces. In addition, rotational molding of foamed parts by pellets needs shorter cycle time, but is counteracted by uneven inner surfaces.
