Mechanical Performance of Injection-Molded Poly(propylene): Characterization and Modeling

It is shown that predictions of local mechanical properties in a product can be made from the orientation only using an anisotropic viscoplastic model. Due to processing-induced crystalline orientations, the mechanical properties of injection-molded polymer products are anisotropic and exhibit strong variations within a product. The tensile response and the mechanical lifetime under static loading depend strongly on the direction of loading and the location. The deformation kinetics are described with an anisotropic viscoplastic model, and quantitative predictions are made based on coupling of the orientation factor in direction of loading and model parameters. A limited characterization of the morphology within a product is sufficient to determine its local mechanical performance.