A new model based approach for the prediction and optimisation of thermal homogeneity in single screw extrusion

In polymer extrusion, delivery of a melt which is homogenous in composition and temperature is important for good product quality. However, the process is inherently prone to temperature fluctuations which are difficult to monitor and control via single point based conventional thermocouples. In this work, the die melt temperature profile was monitored by a thermocouple mesh and the data obtained was used to generate a model to predict the die melt temperature profile. A novel nonlinear model was then proposed which was demonstrated to be in good agreement with training and unseen data. Furthermore, the proposed model was used to select optimum process settings to achieve the desired average melt temperature across the die while improving the temperature homogeneity. The simulation results indicate a reduction in melt temperature variations of up to 60%.

► New model to predict melt temperature at desired die radial positions in extrusion. ► Explored effects of each process parameter on melt temperature homogeneity/level. ► Optimum settings, achieved desired temperature with reduced variance of up to 60%. ► Method to select optimum initial process settings quickly at a high screw speed. ► An alternative method to time-consuming trial and error process setting selection.