INJECTION-MOLDING OF RUBBER COMPOUNDS - EXPERIMENTATION AND SIMULATION

In the present study, we initially dealt with the measurements of the rheological properties of rubber compounds and their vulcanization kinetics. Theoretical expressions were formulated necessary to carry out simulation of flow dynamics, thermal history, and extent of cure of rubber compounds in the mold. Our nonisothermal vulcanization kinetic and induction time models were employed. Major aspects of simulation of rubber injection molding have been considered, including modeling of the flow in the nozzle, sprue, runner system, and cavity, together with the curing behavior. A computer program using both finite-difference and finite-element analyses was utilized for the simulation of cavity filling and curing stages. The predicted results, such as pressure, location of melt front, and state of cure, were compared with the experimental data obtained in several injection molding runs. In addition, some results on the effects of processing upon properties of molded products were reported.