Analysis and modelling of the melting behavior of polymers in co-kneaders
Final Report Abstract
Increasingly complex products are presenting the plastics processing industry with increasing challenges in the preparation of polymers. The co-kneader with its unique functional principle represents a machine type with great potential in this field of application. The co-kneader is a single-screw extruder that performs an oscillating movement in the direction of extrusion in addition to rotation. The up to four rows of kneading pins along the barrel walls, in conjunction with the interrupted screw flights, enable a high degree of mixing with simultaneously gentle processing with manageable shear forces and precise temperature control. Although the cokneader is used for a variety of material systems such as polyvinyl chloride or polyamide and especially for special applications such as thermosets or silicones in industry, the process design is mainly based on trial-and-error tests. In the first phase of the project, the SimKo simulation tool was therefore developed, which can be used to describe the melting, energy balance and flow of polymers in the co-kneader. The analytical modelling approach is based on the assumption of dispersive melting, whereby the contribution of plastic energy dissipation (PED) was initially neglected. For this reason, the second phase of the project investigated the development of a modelling approach, considering the PED, to specify the melting start for different extruder configurations, pellet shapes and material systems more precisely. This will enable an improved design of the preparation process in the future and contribute to an increase in product quality.
Publications
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Simulationstool SimKo
Johannes Rudloff
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Analysis and simulation of the melting behaviour of polymer materials in co-kneaders, 59th ILMENAU SCIENTIFIC COLLOQUIUM, Ilmenau, 2017
Rudloff J., Wilhelm, M., Lang M. & Heidemeyer, P.
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Analysis of the process behavior of co-kneaders, Proceedings of the Polymer Processing Society, Dresden, 2017
Rudloff J., Wilhelm, M., Lang M., Heidemeyer, P. & Bastian M.
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Analysis of the melting behavior of polyethylene and polystyrene in co-kneaders, Proceedings of the Polymer Processing Society 36th Annual Meeting PPS-36, Montreal, 2021
Rudloff J., Wolff, R., Lang M., Hochrein, T. & Bastian M.
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Investigation of influences on the melting of polyethylene and polystyrene in a co-kneader, ANTEC 2021
Rudloff J., Lang M., Hochrein T. & Bastian M.
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Extension of the melting model for co-kneaders regarding the plastic energy dissipation. AIP Conference Proceedings, 3158, 070002. AIP Publishing.
Wolff, Rebecca; Rudloff, Johannes; Baudrit, Benjamin; Hochrein, Thomas; Bastian, Martin & Malatyali, Hatice
