Influence of flow restriction on the microstructure and mechanical properties of long glass fiber-reinforced polyamide 6.6 composites for automotive applications

In this study, polyamide 6.6 with 40 wt% of long glass fibers was processed by injection molding into a mold with the ability to simulate controlled flow restriction. The mechanical properties of the molded test specimens were evaluated to verify the application of the composites as substitutes for metallic materials in automotive applications and the influence of flow restriction on these properties. Mathematical models were used to calculate the tensile strength of the composites in order to validate the experimental results. It was found that the presence of the controlled flow restriction affects fiber length as well fiber orientation, both of which influence the final mechanical properties of the composite. Moreover, a high degree of anisotropy in the mechanical properties was observed.