Abstract
This report investigates the filling phenomena of the water assisted injection moulding process by using a flow visualisation technique. Experiments were carried out on an 80-tonne injection-moulding machine equipped with a laboratory-developed water injection unit. The material used was semi-crystalline polypropylene. A flow visualisation mould was specially designed and made for this study. A high-speed video camera was used to record the mould filling phenomena of rectangular cavities with three-channel geometry and layouts: a flat plate, a plate with two zones of different depths and a plate with symmetric ribs. The interaction between the assisting water and the polymer melt during moulding was observed, and insight into the water penetration behaviour was summarised.