Experimental Study on Effect of Spherical Corner Shape on Improvement of Filling Imbalance of Microstructural Plastic Parts.

The right-angle corners and spherical corners were arranged in the grading part of the flow channel to improve the filling imbalance of microinjection-molded parts. An eight-cavity injection mold with micro-cylinder holes at diameters of 200 and 300 μm was designed. The injection-molding experiment was carried out with high-density polyethylene (PE-HD) as a raw material. The results indicated that as the injection rate and mold temperature increased gradually, the spherical corners became better than the right-angle ones for improving filling imbalance. With an increase in the feature size of the micro-cylindrical hole, the improvement of the filling imbalance could be further enhanced by the right-angle corners and the spherical corners. [ABSTRACT FROM AUTHOR]