Effects of Some Injection Molding Process Parameters on Fiber Orientation Tensor of Short Glass Fiber Polystyrene Composites (SGF/PS)

Calculation of fiber orientation distribution is the reference standard for determining the numerous physical and mechanical properties of injection molded short fiber reinforced thermoplastics. On the other hand, most of the properties of these composites depend on their fiber orientation pattern, which can be represented by tensorial notation, aij. This work focuses on numerical calculation of a fiber orientation tensor of an injection molded short glass fiber polystyrene (SGF-PS) composite part, shaped as a rectangular plate. In this study, the effects of some parameters of the injection molding process including injection flow rate, mold wall temprature, packing pressure and also fiber content on the changes of fiber orientations of this specimen are investigated. Our studies are concentrated on determining the changes of the first orientation tensor component in the flow direction due to different injection parameters. In addition, the changes on tensile modulus of the injected part are simulated in every condition. The simulations show how these molding parameters can influence both fiber orientation and tensile modulus of injection molded parts. At the first step, in order to be confident about the software results, they are validated by experimental data in two cases.