Numerical Modeling of MuCell^® Injection Moulding Process

The results of computer simulation of an injection moulding process with microcellular foaming (MuCell^®) were presented in this work. The processed material was a composite: a polypropylene reinforced with glass fibres (30%). The methodology of preparing the simulation as well as the simulation results were described. The characteristic properties of the forecasted injection moulded part were shown. Finally, the microscopical investigation results of a real injection moulded part were presented and the comparison of simulation results to the microscopical images was made. It was found from the simulation that the sink marks were significantly reduced in the microcellular part in comparison to the part from the conventional process. Moreover, the differences in pores’ distribution in the cross-section in different points, depending on the distance from the sprue, were registered. According to the simulation results, bigger pores were formed in the points at the end of the flow, where a local increase in the pore size in the region near the skin was also noticed. The pores observed on the microscope in the part cross-section were concentrated more in the core and just few pores in the skin were observed. Those in the skin area were smaller, similarly to the simulation results.