Abstract
The development of a mathematical model to be used in a simulation software for the description of rubber extrusion operating points is presented. A discrete model for the flow has been introduced, which considers the flow in the main direction and in the cross section of the screw channel. Moreover the flow model is connected with a discrete model for the computation of the temperature within the screw channel, an FDM approach has been used here. The combination permits the non‐isothermal flow simulation along extruder screws. Beside the isothermal and non‐isothermal option the simulation software, obtained on the basis of the models described, allows a multi‐variation of parameters as well. It is shown how such a variation mode can be used within a screw geometry optimization process and a short comparison of simulated and experimental data for the optimized concept is given. Further examples of comparison simulation/experiment are demonstrating that results can prone to error. The occuring lack of the model is most likely linked to an insufficient description of the rheology of rubber compounds. Further imperfection discussed are the processes within the feeding section. For example feed rolls and grooved barrels are often installed and effective for the process but not considered within theoretical models.
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