Experimental study and calculations of short glass fiber orientation in a center gated molded disc

Abstract Short glass fiber orientation in a center gated molded disc of polyamide is studied using optical microscopy techniques. The very different orientation between the core and the surface of the molding is quantified with an orientation function. The influence of the molding conditions is investigated. A numerical scheme is used for modeling the mold filling with a viscous melted polymer. A computation method is introduced to describe the fiber movement during the flow. The theoretical results are in good agreement with the experimental ones. In particular, the very different orientation between the skin and the core of the disc is well predicted.