Methods of mixing quality control during polymer processing on a disk extruder

Today, the market dictates the need for extrusion systems capable of processing a wide range of different polymers with maximum efficiency. One of the options for such installations is a resource- and energy-saving cascade disk-gear extruder consisting of a metered-discharge disk extruder and a gear pump. The disk extruder is characterized by high mixing capacity and has proven itself as a melt-homogenizer. However, at present there is no unified methodology for selecting the technological parameters of the disk extrusion process depending on the quality of mixing of the material at the outlet, which greatly complicates the introduction of this equipment into the technological schemes of modern production facilities. Based on the analysis of recent scientific publications, a system of equations has been created that describes the movement of material in the disk gap and allows determining the residence time of the material and the length of the trajectory of material movement in the disk gap. Graphs of the dependence of the trajectory length and the duration of the material's stay in the disk gap on the distance to the moving disk are presented. Taking into account the previously obtained empirical data and using the correlation between the criterion of mixing quality and the value of the accumulated strain, a computer program was developed that is capable of selecting the technological parameters of disk extrusion depending on the required mixing quality. Based on the developed system of equations, graphs showing the dependence of the accumulated strain on the size of the disk gap and the rotation frequency of the working body were constructed. Depending on the required mixing quality and extruder performance, the program provides the values of the optimal size of the disk gap and the rotation speed of the working body, which greatly simplifies the process of setting up equipment for specific production conditions and types of materials.