Rheometry of polymer melts using processing machines
Tóm tắt
The technology of slit-die rheometry came into practice in the early 1960s. This technique enables engineers to measure the pressure drop very precisely along the slit die. Furthermore, slit-die rheometry widens up the measurable shear rate range and it is possible to characterize rheological properties of complicated materials such as wall slipping PVCs and high-filled compounds like long fiber reinforced thermoplastics and PIM-Feedstocks. With the use of slit-die systems in polymer processing machines e.g., Rauwendaal extrusion rheometer, by-pass extrusion rheometer, injection molding machine rheometers, new possibilities regarding rheological characterization of thermoplastics and elastomers at processing conditions near to practice opened up. Special slit-die systems allow the examination of the pressure-dependent viscosity and the characterization of cross-linking elastomers because of melt preparation and reachable shear rates comparable to typical processing conditions. As a result of the viscous dissipation in shear and elongational flows, when performing rheological measurements for high-viscous elastomers, temperature-correction of the apparent values has to be made. This technique was refined over the last years at Montanuniversitaet. Nowadays it is possible to characterize all sorts of rheological complicated polymeric materials under process- relevant conditions with viscosity values fully temperature corrected.
Tài liệu tham khảo
Agassant, J.F., P. Avenas, J.P. Sergent, and P.J. Carreau, 1991, Polymer Processing: Principles and Modelling, Hanser Gardner Publications, Cincinnati.
Bagley, E.B., 1957, End correction in the capillary flow of polyethylene, J. Appl. Phys. 28, 624–627.
Brinkman, H.C., 1951, Heat effects in capillary flow, Appl. Sci. Res. A2, 120–124.
Cox, H.W. and C.W. Macosko, 1974, Viscous dissipation in die flows, AIChE J. 20, 785–795.
Daryanani, R., H. Janeschitz-Kriegl, R. van Donselaar, and J. van Dam, 1973, A calorimetric measurement of frictional heat in capillary rheometry of polymer melts, Rheol. Acta 12, 19–24.
Duretek, I. and W. Friesenbichler, 1994, Rheologische Meßsungen mit einem neuentwickelten Extrusionsrheometer, 13. Leobener Kunststoff Kolloquium — Aktuelle Forschungsarbeiten in den Bereichen Spritzgieβen, Extrusion, Rheologie und Messtechnik, 1–28.
Duretek, I., W. Friesenbichler, S. Schuschnigg, and J. Rajganesh, 2006, Viskositätsmeßsungen bei extrem hohen Schergeschwindigkeiten unter Berücksichtigung von Schererwärmung und Druckeinfluss, 19. Leobener Kunststoff Kolloquium — Spritzgieβ- und Extrusionstechnik-Innovationen aus Industrie und Forschung, 1–20.
Eisenschitz, R., B. Rabinowitsch, and K. Weissenberg, 1929, Zur Analyse des Formänderungswiderstandes, Mitteilungen der deutschen Materialprüfungsanstalten, Springer, Berlin, 91–94.
Eswaran, R., H. Janeschitz-Kriegl, and J. Schijf, 1963, A slit viscometer for polymer melts, Rheol. Acta 3, 83–91.
Friesenbichler, W., 1992, Ermittlung von rheologischen Kenndaten für wandgleitende PVC-U Mischungen und ihre Anwendung für Düsenberechnungen beim Extrudieren, Dissertation Thesis, Montanuniversitaet Leoben.
Friesenbichler, W., G.R. Langecker, I. Duretek, and S. Schuschnigg, 2005, Polymer melt rheology at high shear rates using a new micro-rheology technique, 21th Polymer Processing Society Annual Meeting, Leipzig, Germany.
Friesenbichler, W., I. Duretek, J. Rajganesh, and S. R. Kumar, 2011, Measuring the pressure dependent viscosity at high shear rates using a new rheological injection mold, Polimery 56, 58–62.
Friesenbichler, W., J. Rajganesh, T. Lucyshyn, P. Filz, and K. Webelhaus, 2010, Measurement of pressure dependent viscosity and its influence on injection molding simulation, 4th International PMI Conference, Ghent, Belgium, 215–219.
Gornik, C., 2005, Viscosity measurement: Determining rheological data directly at the machine, Kunststoffe Int. 95, 88–92.
Hay, G., M.E. Mackay, K.M. Awati, and Y. Park, 1999, Pressure and temperature effects in slit rheometry, J. Rheol. 43, 1099–1116.
Holzer, C., 1996, Messverfahren zur praxisnahen rheologischen Charakterisierung von Kautschuken, Dissertation Thesis, Montanuniversitaet Leoben.
Holzer, C. and G.R. Langecker, 1997, Praxisnahe rheologische Untersuchungen an einer EPDM-Mischung, KGK-Kautsch. Gummi Kunstst. 50, 648–652.
Knappe, W. and E. Krumböck, 1986, Slip flow of non-plasticized PVC compounds, Rheol. Acta 25, 296–307.
Krumböck, E., 1984, Zum Wandgleiten von PVC-hart Mischungen im fließfähigen Zustand, Dissertation, Montanuniversitaet Leoben.
Laun, H.M., 1983, Polymer melt rheology with a slit die, Rheol. Acta 22, 171–185.
Laun, H.M., 2003, Pressure dependent viscosity and dissipative heating in capillary rheometry of polymer melts, Rheol. Acta 42, 295–308.
Mitsoulis, E., L. Perko, and W. Friesenbichler, 2014, Capillary flow behavior of a rubber compound, Polymer Processing Society Regional Conference Europe-Africa, Tel Aviv, Israel.
Mooney, M., 1931, Explicit formulas for slip and fluidity, J. Rheol. 2, 210–222.
Offermann, H., 1972, Die Rheometrie wandgleitender Kunststoffschmelzen, untersucht am Beispiel von Hart-PVC, Dissertation Thesis, RWTH Aachen University.
Perko, L., M. Fasching, and W. Friesenbichler, 2014, Model for the prediction of bulk temperature changes and pressure losses in rubber compounds flowing through conical dies: an engineering approach, Pol. Eng. Sci. 55, 701–709.
Rauwendaal, C. and F. Fernandez, 1984, Experimental study and analysis of a slit-die viscometer, Pol. Eng. Sci. 25, 765–771.
Schuschnigg, S., 2004, Rheologische Untersuchungen bei hohen Schergeschwindigkeiten mit Hilfe eines Mikrorheologie-Schlitzdüsen Messsystems, Master Thesis, Montanuniversitaet Leoben.
Wales, J.L.S., J.L. den Otter, and H. Janeschitz-Kriegl, 1965, Comparison between slit viscometry and cylindrical capillary viscometry, Rheol. Acta 4, 146–152.
Winter, H.H., 1977, Viscous dissipation in shear flow of molten polymers, Adv. Heat Transf. 13, 205–267.