NON-ISOTHERMAL RADIAL FILLING OF CENTER-GATED DISK CAVITIES WITH VISCOELASTIC POLYMER MELTS

A comprehensive two-dimensional mathematical model is developed for injection mold filling of disk-shaped cavities. The model takes into account the effects of viscoelasticity, non-isothermality, fountain flow and the shape of the flow front. A new variable slip boundary condition is used to avoid discontinuities in the flow structure and to maintain the shape of the flow front. The predictive capabilities of the model include radial and transverse velocities, pressures, temperatures, shear stresses, and the first- and second-normal stress differences throughout the filling stage. Results of the simulations, obtained using the White-Metzner (viscoelastic) and the generalized Power-law (inelastic) constitutive equations, indicate that the viscoelasticity does not significantly affect the velocity and temperature profiles; however, its effect on the stress distributions is substantial.