3-DIMENSIONAL MODELING OF REACTION INJECTION-MOLDING .1.

In this research a model to simulate both the filling the curing stage s of a reaction injection molding (RIM) process in complex three-dimen sional molds is developed. This model can be used to predict not only the temperature and conversion changes with time but also the front po sition during filling. Using given physical and chemical properties of the RIM system, moldability can be determined in advance. The numeric al techniques used in this research include adaptation of the SIMPLE a lgorithm developed by Patankar for a moving-front, two-phase system wi th non-negligible inertial effects, and exothermic chimical reaction. The model predictions of temperature and conversion compare favorably with available data on simple two-dimensional molds. The ability of th e model to predict the dynamics of filling in more complicated molds w as verified by comparison to mold filling experiments with water and a polyurethane foam.