Experimental Analysis of Heat Transfer in Rotational Molding Process

Abstract Rotational molding is a process by which powdered or liquid plastics are converted into hollow articles. This process is relatively simple in a technical point of view but it involves very complex physical phenomena. Constant quality in technical parts requires the mastery of the process by controlling on line these phenomena. One of these of first importance is heat transfer. This paper concerns the experimental analysis of heat transfer in rotational molding process with semi-crystalline polymer. By using an instrumented mold associated with an original radio transmission data acquisition system, we demonstrate that the rotational nature of the process implies complex heat transfer evolutions in the mold. The crystallization of the material is modeled with accuracy by coupling heat transfer equation to a kinetic model determined by calorimetry. It appears that thermal contact resistance evolution is a key point of heat transfer during the solidification of the polymer.