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Melt conveying in co-rotating twin screw extruders / M. Mours in INTERNATIONAL POLYMER PROCESSING, Vol. XV, N° 2 (06/2000)
[article]
Titre : Melt conveying in co-rotating twin screw extruders : Experiment and numerical simulation Type de document : texte imprimé Auteurs : M. Mours, Auteur ; D. Reinelt, Auteur ; H.-G. Wagner, Auteur ; N. Gilbert, Auteur ; J. Hofmann, Auteur Année de publication : 2000 Article en page(s) : p. 124-132 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : Computational fluid dynamics (CFD) based on a finite-volume method was used to simulate three-dimensional pressure and velocity fields for non-Newtonian fluids in fully filled screw elements in a co-rotating twin screw extruder. The employed method also allows the calculation of temperature fields for non-isothermal flow which requires a non-steady state calculation.
The CFD code was first evaluated on simple flow cases such as flow of a Newtonian or non-Newtonian fluid through a cylindrical die or flow in single screw extruders equipped with different screws. The results agreed very well with analytical calculations (die flow) and experimental results (single screw extruder). In a next step, we wanted to establish the reliability of the numerical results for twin screw extruders by performing experiments on a 40 mm and a 58 mm screw diameter machine. Temperature and pressure distribution along the screw in the fully filled section in front of the die were measured. Melt conveying in several screw elements (different pitches) was studied for different materials (amorphous polystyrene and partially crystalline polypropylene) at various flow rates and screw speeds. It was attempted to measure axial pressure build-up for flow rates from nearly zero to beyond the drag capacity of the specific element. The measured bulk values of pressure were then compared to the corresponding values extracted from the CFD simulation results. So far, only isothermal calculations (at different temperatures) have been performed. The temperature profile along the screw was determined by calculating the energy dissipation in isothermal slices and converting the dissipated energy into internal energy (temperature increase, neglecting heat losses at the wall). General agreement between experimental and numerical results is good.Note de contenu : - NUMERICAL SIMULATION OF EXTRUDER FLOW : Governing equations - Numerical method - Test cases DOI : 10.3139/217.1590 En ligne : https://drive.google.com/file/d/1brSajc7UbeqEeYwnuoR-xSeyhU4Qm-ee/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=16050
in INTERNATIONAL POLYMER PROCESSING > Vol. XV, N° 2 (06/2000) . - p. 124-132[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 001012 - Périodique Bibliothèque principale Documentaires Disponible Process behaviour of special mixing elements in twin-screw extruders / H. Potente in INTERNATIONAL POLYMER PROCESSING, Vol. XVI, N° 4 (12/2001)
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Titre : Process behaviour of special mixing elements in twin-screw extruders Type de document : texte imprimé Auteurs : H. Potente, Auteur ; Karsten Kretschmer, Auteur ; J. Hofmann, Auteur ; M. Sengelin, Auteur ; M. Mours, Auteur ; G. Scheel, Auteur ; Th. Winkelmann, Auteur Année de publication : 2001 Article en page(s) : p. 341-350 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 668.9 Polymères Résumé : Mixing and screw extrusion - Tightly intermeshing, co-rotating twin-screw extruders are commonly employed for tasks requiring good mixing. The modular structure of both barrel and screw makes it possible to optimize the extruder configuration for a given task. Increasing demands on polymers have resulted in the development of more sophisticated mixing elements. In the framework of this investigation we looked at the pressure-throughput behaviour of mixing elements in a conveying, reconveying and conveying-reconveying configuration. furthermore, the local residence time distribution within those elements was investigated. We developed physical-mathematical models to describe the pressure-throughput behaviour observed in the experimental investigations. DOI : 10.3139/217.1664 En ligne : https://drive.google.com/file/d/14Y7YG9I7tsVPUVXEymD3Hr6P9xqvSiTh/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15918
in INTERNATIONAL POLYMER PROCESSING > Vol. XVI, N° 4 (12/2001) . - p. 341-350[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 001018 - Périodique Bibliothèque principale Documentaires Disponible