The Role of the Interaction Coefficient in the Prediction of the Fiber Orientation in Planar Injection Moldings

The mechanical properties of injection molded parts in glass reinforced materials are sensitive to processing. A successful design requires a good estimate of the product performance before production. Its performance is strongly affected by the fiber orientation field set up during processing. The fiber orientation pattern is complex and varies three-dimensionally in the moldings. Some commercial simula- tion programs already allow the prediction of the fiber orientation induced during the flow by the associated stress field. The results from the simulations are depend- ent on a parameter accounting for the interactions between fibers during the flow, known as the fiber interaction coefficient. In this paper the effectiveness of the interaction parameter on controlling the predicted patterns of the fiber orientation is studied. This is done by comparing and analyzing the experimental data and the corresponding predictions.