Modeling the solid conveying section of single-screw extruders at high screw speeds considering the pressure build-up

• Applicant: Professor Dr.-Ing. Volker Schöppner
• Subject Area: Plastics Engineering
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 242845944

Solid conveying is an important process part of plastic extrusion. In this proposal it is to be investigated and modelled up to high screw speeds considering the pressure build-up. Commonly known models describing the solid conveying in single screw extruders assume a fully filled screw channel and a plug flow. At high screw speeds however, these assumptions are no longer valid. Therefore, the channel filling and the solid conveying throughput are investigated in this proposal using Discrete-Element-Simulations, which allow the consideration of single particles motions. The solid conveying model, based on such DEM simulations and found in the previous proposal is to be extended to also considering the pressure build-up. To be able to simulate the pressure build-up accurately, an appropriate material model and suitable simulation parameters have to be determined. Afterwards the conducted simulations are validated by experimental solid conveying investigations. Therefore, a stand has to be constructed. Finally, a further optimization of the hopper opening geometry is scheduled in order to reduce the well-known recirculation phenomenon which takes place in the hopper opening and becomes important at high screw speeds. This optimization will also be based on the previous proposals research results.

• DFG Programme: Research Grants