Novel morphologies produced by active shear rotation during injection molding

Abstract

A special mold with mechanically driven mold surface motions (rotation and axial) was developed allowing the imposition of different molding sequences, thus enlarging the possibilities of controlling the thermomechanical environment, and consequently the manipulation of the developed morphology. In this work, centre gated discs were injection molded with distinct rotation velocities of the mold surface. The moldings were characterized by several structure sensitive techniques. The imposition of a mold surface rotation has a marked effect on the morphology of the moldings, with novel molding morphologies being developed: a laminated skin–core structure featuring a dual shish-kebab structure differently oriented relatively to the flow direction, one in each of the skin layer.