APPLICATION OF THE METHOD OF ELLIPSES FOR DETERMINING FIBER ORIENTATION IN LONG FIBER COMPOSITES

摘要

In this paper the Method of Ellipses (MoE) as developed for determining orientation of short fiber composites is analyzed when applied directly to long fiber composites. Fiber orientation within long glass fiber polypropylene composites in center-gated injection molded discs was determined at various percentages of the flow direction. The results were compared directly to short fiber results for the same geometry. In addition, end-gated plaques were molded using the same short and long fiber materials for additional comparison. Results suggest that an area of high radial flow occurs for long fibers at low fill percentages during the filling process for end-gated plaques. Due to the increased length, long fibers have a large increase in flexibility and curvature within the injection molded system, complicating flow and prediction of orientation.