Compounding, Rheology and Numerical Simulation of Highly Filled Graphite Compounds for Potential Fuel Cell Applications
Highly filled plastics may offer a suitable solution within the production process for bipolar plates. However, the compounding of conductive additives and the homogeneous mixing of the plastic melt, as well as the accurate prediction of the material behavior, pose a major challenge for polymer engi...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/15/12/2589 |
| _version_ | 1797592960785711104 |
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| author | Alptekin Celik Fabian Willems Mustafa Tüzün Svetlana Marinova Johannes Heyn Markus Fiedler Christian Bonten |
| author_facet | Alptekin Celik Fabian Willems Mustafa Tüzün Svetlana Marinova Johannes Heyn Markus Fiedler Christian Bonten |
| author_sort | Alptekin Celik |
| collection | DOAJ |
| description | Highly filled plastics may offer a suitable solution within the production process for bipolar plates. However, the compounding of conductive additives and the homogeneous mixing of the plastic melt, as well as the accurate prediction of the material behavior, pose a major challenge for polymer engineers. To support the engineering design process of compounding by twin-screw extruders, this present study offers a method to evaluate the achievable mixing quality based on numerical flow simulations. For this purpose, graphite compounds with a filling content of up to 87 wt.-% were successfully produced and characterized rheologically. Based on a particle tracking method, improved element configurations were found for twin-screw compounding. Furthermore, a method to characterize the wall slip ratios of the compounded material system with different filler content is presented, since highly filled material systems often tend to wall slip during processing, which could have a very large influence on accurate prediction. Numerical simulations of the high capillary rheometer were conducted to predict the pressure loss in the capillary. The simulation results show a good agreement and were experimentally validated. In contrast to the expectation, higher filler grades showed only a lower wall slip than compounds with a low graphite content. Despite occurring wall slip effects, the developed flow simulation for the design of slit dies can provide a good prediction for both low and high filling ratios of the graphite compounds. |
| first_indexed | 2024-03-11T02:00:42Z |
| format | Article |
| id | doaj.art-1ef1cb50d28644aa99377373e10a9815 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-11T02:00:42Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-1ef1cb50d28644aa99377373e10a98152023-11-18T12:11:50ZengMDPI AGPolymers2073-43602023-06-011512258910.3390/polym15122589Compounding, Rheology and Numerical Simulation of Highly Filled Graphite Compounds for Potential Fuel Cell ApplicationsAlptekin Celik0Fabian Willems1Mustafa Tüzün2Svetlana Marinova3Johannes Heyn4Markus Fiedler5Christian Bonten6Institut für Kunststofftechnik, University of Stuttgart, 70569 Stuttgart, GermanyInstitut für Kunststofftechnik, University of Stuttgart, 70569 Stuttgart, GermanyInstitut für Kunststofftechnik, University of Stuttgart, 70569 Stuttgart, GermanyCoperion GmbH, 70469 Stuttgart, GermanyCoperion GmbH, 70469 Stuttgart, GermanyCoperion GmbH, 70469 Stuttgart, GermanyInstitut für Kunststofftechnik, University of Stuttgart, 70569 Stuttgart, GermanyHighly filled plastics may offer a suitable solution within the production process for bipolar plates. However, the compounding of conductive additives and the homogeneous mixing of the plastic melt, as well as the accurate prediction of the material behavior, pose a major challenge for polymer engineers. To support the engineering design process of compounding by twin-screw extruders, this present study offers a method to evaluate the achievable mixing quality based on numerical flow simulations. For this purpose, graphite compounds with a filling content of up to 87 wt.-% were successfully produced and characterized rheologically. Based on a particle tracking method, improved element configurations were found for twin-screw compounding. Furthermore, a method to characterize the wall slip ratios of the compounded material system with different filler content is presented, since highly filled material systems often tend to wall slip during processing, which could have a very large influence on accurate prediction. Numerical simulations of the high capillary rheometer were conducted to predict the pressure loss in the capillary. The simulation results show a good agreement and were experimentally validated. In contrast to the expectation, higher filler grades showed only a lower wall slip than compounds with a low graphite content. Despite occurring wall slip effects, the developed flow simulation for the design of slit dies can provide a good prediction for both low and high filling ratios of the graphite compounds.https://www.mdpi.com/2073-4360/15/12/2589fuel cellbipolar platescompoundingtwin-screw extrusiongraphite compoundCFD |
| spellingShingle | Alptekin Celik Fabian Willems Mustafa Tüzün Svetlana Marinova Johannes Heyn Markus Fiedler Christian Bonten Compounding, Rheology and Numerical Simulation of Highly Filled Graphite Compounds for Potential Fuel Cell Applications Polymers fuel cell bipolar plates compounding twin-screw extrusion graphite compound CFD |
| title | Compounding, Rheology and Numerical Simulation of Highly Filled Graphite Compounds for Potential Fuel Cell Applications |
| title_full | Compounding, Rheology and Numerical Simulation of Highly Filled Graphite Compounds for Potential Fuel Cell Applications |
| title_fullStr | Compounding, Rheology and Numerical Simulation of Highly Filled Graphite Compounds for Potential Fuel Cell Applications |
| title_full_unstemmed | Compounding, Rheology and Numerical Simulation of Highly Filled Graphite Compounds for Potential Fuel Cell Applications |
| title_short | Compounding, Rheology and Numerical Simulation of Highly Filled Graphite Compounds for Potential Fuel Cell Applications |
| title_sort | compounding rheology and numerical simulation of highly filled graphite compounds for potential fuel cell applications |
| topic | fuel cell bipolar plates compounding twin-screw extrusion graphite compound CFD |
| url | https://www.mdpi.com/2073-4360/15/12/2589 |
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