Analysis of the process behavior for planetary roller extruders

In the last few years process models for the planetary roller extruders were developed. These models are allowing an estimation of the processes in the extruder for the first time. However, because of the simplifications that were used for modeling, there can be considerable differences between simulated and experimental results. In this paper, a dimensionless approach for modeling the planetary roller extrusion process is proposed to improve the model quality. Therefore experimental trials with a variation of extruder configuration, material type, throughput and screw speed had been conducted. At these experiments the pressure build up was determined. Based on the results drag flow rate and pressure flow rate were expressed as dimensionless operating numbers to show the influence of power law index and geometry on the pressure building capacity of the extruder. This can help to find more precise assumptions for the process models.