Polymer melt flow behavior in the coinjection molding process

摘要

An experimental study of the co-injection molding process was carried out. The fingering instability due to the difference in viscosities of the two materials gave rise to early breakthrough of the core material and nonuniform skin layer thickness. The core material was also used as tracer material for flow visualization of the injection molding process. the V formation near the wall as well as the mushroom effect, previously predicted, was observed.