The goal of this study is to investigate segregation in the runner system during injection
moulding. Segregation is a phenomenon which occurs during the injection moulding of
filled or reinforced polymer systems. The effects of segregation can be so severe
that the process can lead to waste products. Even though segregation is an important
problem, so far it has been little researched. However, it would be very beneficial
if segregation during injection moulding could be predicted through simulation software.
In order to achieve that, we must first understand what causes segregation. We injection
moulded several specimens using polypropylene, a transparent polymer, and used 10.8
V% ceramic beads as filler with different injection moulding parameters. We investigated
the effect of melt temperature and injection rate, which were set to 180, 220, 260
°C and 5, 20, 80 cm 3 /s. We observed segregation with an optical microscope and used
a furnace to burn the PP and measured the weight of the leftover beads in order to
determine the bead content in various regions.
