| Abstract: | The maximum flow length of a polymer for a given set of processing conditions is important in injection molding to avoid incomplete mold filling. Experimental analysis, using various processing conditions, can generate the actual influence of processing conditions on the maximum flow length. However, the experimental determination of the flow length for all known industrial polymers would be time consuming and expensive. A non-Newtonian, nonisothermal model of mold filling was developed to evaluate the flow length without requiring large amounts of computation time. The model implements the use of both a temperature and shear rate–dependent viscosity as well as viscous heating. This paper presents the model and its numerical implementation, followed by simulation results. The model is compared with other simulation programs and experimental results using both an amorphous Styron 484-27 polystyrene and a semicrystalline 640I polyethylene in a spiral mold geometry. Good agreement between the three is observed. |
