The crystallinity distribution of polymers has a significant dependence on injection processing and determines the part properties.Speed
pressure and temperature fields are obtained from 3D numerical simulation by employing GLS (Galerkin/least-squares)
SUPG (Streamline upwind/Petrov-Galerkin) and GGLS (Galerkin gradient least-squares) methods.The non-isothermal shear stress-induced crystallization kinetics models are proposed based on the hypothesis that shear stress induced orientation of polymer chains increases the equilibrium melting temperature.The relationship between crystallinity and injection processing is modeled.SUPG method is used for the stabilized finite element formulation of crystallinity evolution in flow.Simulations for polypropylene were carried out under different processing conditions such as different injection speeds and mold temperatures
melt temperatures
and the results show that crystallinity is very low and can be neglected when the filling stage is over because of short injection time and high melt temperature.Crystallinity distribution in the final part is determined by processing parameters which can be varied to bring on the special crystallinity distribution.Latent heat due to crystallization may often affect the temperature field very much during the cooling stage.