Simulation of Non-Isothermal Flow Field of Melt in Rubber Extrusion Dies

Under non-isothermal conditions, rubber die profile of car seal is reversely and numerically designed and the extrusion process of the die simulated, using the CFD package Polyflow. The non-isothermal flow field of the die is calculated. Effect of temperature on the structural size of the die and rubber melt rheological behaviors are discussed. The results showed that along the direction of flow of the melt, the average velocity and average pressure of the melts in the die in the non-isothermal conditions are larger than that under the isothermal conditions; and the average shear stress and viscosity of the melts are smaller. Comparing the numerical size of the rubber die with that of the actual product, the non-isothermal numerical size of the rubber die is better than the isothermal one. Relative error of the die size for the non-isothermal simulation is only 1.63%. Simulation of die extrusion process in non-isothermal condition is closer to the actual process. The quality of the dies and products can be improved using the non-isothermal constitutive equation.