Annular cavity filling and curing in an epoxy RIM process is simulated numerically for the various operating conditions. For the analysis of the filling step, the flow field is divided into two subdomains : the main flow region where the materials have one dimensional flow, and the front region where the materials have two dimensional flow. The effect of the operating conditions on the temperature and conversion rate inside the mold is analyzed numerically by the upwind differencing scheme.
When the temperature of the material to be injected becomes higher, the reaction rate increases rapidly and brings about the corresponding temperature increase in the mold. The excessive high temperature may cause the polymerized epoxy to be thermally degraded. Thus the temperature increase of the inlet material has to be limited.
The temperature increase at the mold wall shows the similar effect. The temperatures at the mold wall and of the inlet material are the important factors of the process. A relation between the fill time and the maximum inlet pressure is also deduced.