Morphology of fluid assisted injection molded polycarbonate/polyethylene blends

This study has examined the morphological development in fluid assisted injection molded HDPE/PC blends. Samples for microscopic observation were prepared by an 80-ton injection-molding machine equipped with a tube cavity and with both gas and water injection units. It was observed that the shape and size of the dispersed phase depended onthe position both across the part thickness and along theflowdirection. Water molded parts with a smaller PC particle distribution than gas. Additionally, high fluid pressures were found to mold parts with smaller PC particle distribution. For both gas and water assisted injection molding, small and large particles coexisted in the skin and subskin layers, indicating that both coalescence and breakup of the dispersed phase occurred in that layer. These findings are expected to help foster understanding of the mechanism of morphology evolution during the melt filling, fluid injection,andcooling stages of the fluid assisted injection molding process.