Extrusion units for processing multicomponent mixtures

In this work, extrusion units designed for the processing of multicomponent mixtures, in particular polymer compositions, are considered. The analysis was carried out on the basis of existing designs of worm extruders, which are used in industry for processing thermoplastic materials. The research focuses on issues related to the processing of mixtures consisting of several components that have different physicochemical properties, which require different conditions for processing each of them. Worm extruders are the most common type of equipment for polymer processing processes, but their use requires consideration of the specifics of each component of the mixture. This is due to the fact that under the same processing conditions, the properties of individual components can differ significantly, which can lead to the inefficiency of the process or to obtaining a low-quality final product. Several prototypes of extruders are examined in detail and critically evaluated, in particular designs of extrusion units with modified zones of mixing and dosing of components. Designs using simultaneous dosing of several components, their pre-mixing, as well as designs that involve individual processing of each component before combining them are described. This allows for better homogeneity of the mixture, which is critical for obtaining a high-quality final product. Extruder designs were also considered, which offer different approaches to the organization of the mixing and extrusion process of multicomponent mixtures and use separate screws for each component or extruders with a sectional design, which allows the adjustment of the process to specific production needs. The advantages and disadvantages of each of the considered options are indicated, in particular, the simplicity of the design, the efficiency of mixing, the accuracy of dosing, as well as energy consumption. As a result, a thorough comparison of various designs of extrusion units was provided, their key advantages and disadvantages were identified, and recommendations were provided for the optimal layout of units for processing multicomponent mixtures in various industries.