Effect of viscous dissipation on the temperature of the polymer during injection molding filling

Abstract

Abstract During injection molding, viscous dissipation changes the temperature distribution by playing the role of an energy source, which affects heat transfer rates. Understanding the effect of the viscous dissipation assists the designing of the cooling system in injection molding process. In this article, the effect of the viscous dissipation on the temperature distribution throughout a rectangular channel for different polymers at different inlet velocities and temperatures is studied. A cross type rheological model depending on the temperature and pressure is assumed for polymer materials polystyrene (PS) and polypropylene (PP). The evolution of the flow velocity inside the channel is presented. The quantity of heat added due to viscous dissipation to the polymer is also calculated up to different positions through the channel. A numerical finite volume code for the simulation of polymer melt flow in a channel is used and a validation of this numerical code is presented. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.