Validation of a three-dimensional moldflow cooling analysis for rapid tooling inserts

In this study, injection molding rapid tooling materials and processes were used to produce thick walled TPE parts. Mold filling and cooling computer simulations were completed to compare the cycle times of conventionally prepared steel inserts to the rapid tooling inserts.; Two thick walled part geometries were fabricated in DTM's RapidSteel™ 2.0. From several builds, using a toothbrush handle geometry a method for mapping a complex surface, to determine the amount of material removal during machining, was suggested. A cap geometry was used from which molded part cycle time was compared to that of a convention P-20 steel tool material using a TPE plastics material. In an effort to reduce cycle time, a thick section of the cap part was cored out and the cycle time was compared with the unmodified cap geometry. Finally, computer filling and cooling analyses were used to simulate and predict the molding of these two geometries in P-20 steel.; The molding cycle times for a TPE plastics material compared favorably to computer simulation cooling predictions. Frozen time plots as predicted by the simulation seemed to correlate fairly well with an observation of the amount of internal molten material at the end of a cycle.