COMPUTING VISCOELASTIC FLOW OF POLYMER MELT IN INJECTION MOLDING

摘要

Flow induced stresses, caused by viscoelastic flow of the polymer during the filling and post-filling stage, determines the anisotropy of mechanical, thermal and optical properties and influences the long term dimensional stability. A numerical method for solving viscoelastic fluid flow problem is presented in this study. The governing equations are in terms of generalized Hele-Shaw flow for incompressible, non-Newtonian, non-isothermal fluid and Maxwell model. The conventional Galerkin method is employed to discrete the constitutive equations expressed by pressure gradient, while the implicit scheme combined with up-wind method is used to discrete the energy equation. The typical example proves the viscoelastic constitutive relation is significantly better than the viscous.