Investigation of the influence of the cylinder temperature control on the process behavior of single-screw extruders and design of a practical cylinder temperature control

• Applicant: Professor Dr.-Ing. Volker Schöppner
• Subject Area: Plastics Engineering
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282084275

The process-oriented behavior and thus selectively influencing the behavior of screw machines on the choice of cylinder temperature profile often requires a high understanding of the process and a great deal of experience in product processing. Here, the choice of the temperature profile is of great importance for the later quality of the product to be processed and also has impact on the efficiency of the system. Various research projects have already been proven that specific adaptation of the cylinder temperature profile to the respective process lead to an increase in output rates with otherwise the same process conditions. In addition, there is a great potential in the improvement in terms of energy, because a wrong chosen temperature profile may lead to worse melting performances in the process and the energy introduced often has to be removed again unused with cooling units. The problem declines, if regularly varying process parameters, different materials and screw geometries are used in the processing, so that a continuous adaptation of the temperature control is required. The aim of this research project should be to conduct investigations in the field of cylinder temperature control, with influence and control variables are to be identified in the process, from which derive optimization strategies can be determined and transformed in an appropriate temperature control. The to be determined control system is assumed to be an independent expert system, which can be added with codes of practice and experimental model laws from the previous process points. The control technology mapping of the entire system should be done by the abstraction of the extrusion process framed in a model level. By dividing into sub-processes and mutual consideration of sub-processes with each other, the reaction between thermal, rheological and actuator-based processes can be modelled. In addition, heat transfer effects, which also take place by conduction in the screw and barrel areas and mutually by convection with the melt, will be considered and by that combined with the already developed models for the description of the temperature profiles in screw machines. This will lead ultimately to a better predictability of extrusion processes. At the end of the project, the implementation of the temperature control system should be located in an existing extrusion system, to which numerous studies validating the mentioned model approaches are planned.

• DFG Programme: Research Grants