Compression Molding Simulation of Rubber Materials

Compression molding is a process by which pressure is applied to a material by a heat mold. In the case of thermoset elastomers (rubber), the heat and pressure initiate cross linking of the polymer. A specific weight and shape of a material (called a preform) is placed into an open mold, after which the mold halves close. This compression stroke forces the resin to flow and fill out the cavity. After the mold is filled and pressure is applied for a given time (cure time) the mold is split open and the part is removed either by hand or by ejection methods. This process can be applied to both thermoplastic and thermoset materials, both with or without fiber reinforcement. Compression molding simulation can help determine the feasibility and conditions of the manufacturing process, including the size and placement of the preform(s), the internal cavity pressures, and temperatures during the process. These factors enable us to determine how tool and process design affect product quality. During this class, we will discuss an application of compression molding and compare it with compression molding analysis results.