The influence of material properties and process parameters on energy consumption during extrusion of flexible PVC

The aim of this work is to investigate the correlation between the process settings, the material properties, and the extrusion energy consumption. Experiments were conducted on a laboratory extruder, testing different flexible PVCs. During continuous single-screw extrusion for various process conditions, power signals were recorded for the extruder's motor and the entire machine. According to the results of the previous works, the absorbed current, the power factor, and the total active power increased with the screw speed for all the tested materials. However, due to the high content of additives, the considered materials exhibited wall-slip during extrusion, and the influence of the slip behavior on the specific energy consumption was evaluated too. It was found that the specific energy consumption did not decrease monotonically with the screw speed, and thus the maximum energy efficiency can not always be achieved at the highest screw speed. Significant correlations were found between the material's hardness, viscosity, and process energy usage, with the hardest and most viscous materials requiring more energy to be extruded.