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Licensed Unlicensed Requires Authentication Published by De Gruyter November 4, 2014

Verifying the Melting Behavior in Single-Screw Plasticization Units Using a Novel Simulation Model and Experimental Method

M. Aigner, B. Praher, C. Kneidinger, J. Miethlinger and G. Steinbichler

Abstract

We report on the development of a novel non-invasive ultrasonic measurement system for determining the melting behavior in a single-screw plasticization unit (35/22D) and on a modified drag-induced melt removal model that builds upon that by Tadmor and Gogos (2006). The solid bed to melt pool ratio is quantified using a non-invasive ultrasonic system based on reflection measurements. Automated analysis of the reflected pulses – measured at different axial positions along the barrel – allows the melting process to be monitored online. Our analysis of the delay section incorporates viscous dissipation into Tadmor's drag-induced melt removal model. We link temperature profile and melt film thickness via differential equations and consider viscous dissipation. By segmenting the delay section in the axial direction, the temperature dependency of the thermo-physical material properties is also considered. Using the melting behavior measured for different materials, we verified the mathematical model. Additionally, the effect of reduced screw length on the plasticization process, important for the injection molding process, was investigated.


* Mail address: Michael Aigner, Institute of Polymer Extrusion and Compounding, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz, Austria. E-mail:

References

Binder, W., “Modellierung der Transportvorgänge in Einschneckenextrudern“, PhD Thesis, Leoben (1999)Search in Google Scholar

Bronstein, I. N., Semendjajew, K. A.: Taschenbuch der Mathematik, Teubner Verlagsgesellschaft, Leipzig, Moskau (1977)Search in Google Scholar

Brown, E. C., Dawson, A. J. and Coates, P. D., “Ultrasonic Monitoring of Nozzle and Cavity during Injection Moulding”, J. Reinf. Plast. Compos., 21, 441450 (2002)10.1177/0731684402021005444Search in Google Scholar

Brown, E. C., Olley, P. and Coates, P. D., “In Line Melt Temperature Measurement during Real Time Ultrasound Monitoring of Single Screw Extrusion”, Plastics, Rubber and Composites, 29, 313 (2000)10.1179/146580100101540644Search in Google Scholar

Brown, E. C., Olley, P., Collins, T. L. D. and Coates, P. D., Ultrasonic Investigations of Process Variation In-Line During Single Screw Extrusion and Injection Moulding: Real Time Detection of Temperature Profile and Material Degradation, Proceedings of the 15th Annual Meeting of the Polymer Processing Society, Netherlands (1999)Search in Google Scholar

Donovan, R. C., “A Theoretical Melting Model for Plasticating Extruders”, Polym. Eng. Sci., 11, 247257 (1971)10.1002/pen.760110313Search in Google Scholar

Elbirli, B., LindtJ.T., “Mathematical Modelling of Melting of Polymers in a Single-Screw Extruder”, Polym. Eng. Sci., 24, 988999 (1984)10.1002/pen.760241208Search in Google Scholar

Elbirli, B., Lindt, J. T., Gottesgetreu, S. R. and Baba, S. M., “Mathematical Modeling of Melting of Polymers in Barrier-Screw Extruders”, Polym. Eng. Sci., 23, 8694 (1983)10.1002/pen.760230207Search in Google Scholar

Jen, C. K., Zun, Z. and Kobayashi, M., “Real-Time Monitoring of Barrel Thickness and Barrel/Screw Separation Using Ultrasound”, Meas. Sci. Technol., 16, 842 (2005)10.1088/0957-0233/16/3/028Search in Google Scholar

Kim, J. G., Kim, H., Kim, H. S. and Lee, J. W., “Investigation of Pressure-Volume-Temperature Relationship by Ultrasonic Technique and its Application for the Quality Prediction of Injection Molded Parts”, Korea-Australia Rheology Journal, 16, 163168 (2004)Search in Google Scholar

Lindt, J. T., “A Dynamic Melting Model for a Single Screw Extruder”, Polym. Eng. Sci., 16, 284291 (1976)10.1002/pen.760160411Search in Google Scholar

Liu, T., Wong, A. C.-Y. and Zhu, F., “Prediction of Screw Length Required for Polymer Melting and Melting Characteristics”, Int. Polym. Proc., 16, 113123 (2001)10.3139/217.1639Search in Google Scholar

Maddock, B. H., “A Visual Analysis of Flow and Mixing in Extruder Screws”, SPE-Journal, 15, 383389 (1959)Search in Google Scholar

Miethlinger, J., “Extrusion of Cast Films – Plant Technologies and Product Properties”, PHD-Thesis, Leoben (2001)Search in Google Scholar

Mount, E. M., Wangon, J. G. and Chung, C. I., “Analytical Melting Model for Extrusion: Melting Rate of Fully Compacted Solid Polymers”, Polym. Eng. Sci., 22, 729737 (1982)10.1002/pen.760221202Search in Google Scholar

Mulvaney-Johnson, L., Cheng, C. C., Ono, Y., Brown, E. C., Jen, C. K. and Coates, P. D., “Real Time Diagnostics of Gas/Water Assisted Injection Moulding Using Integrated Ultrasonic Sensors”, Plastics, Rubber and Composites, 36, 111121 (2007)10.1179/174328907X177617Search in Google Scholar

NoriegaM. DelP., Osswald, A. T. and Ferrier, N., “Inline Measurement of the Polymer Melting Behavior in Single Screw Extruders”, J. Polym. Eng., 24, 557578 (2004)10.1515/POLYENG.2004.24.6.557Search in Google Scholar

Ono, Y., Jen, C. K., Cheng, C. C. and Kobayashi, M., “Real-Time Monitoring of Injection Molding for Microfluidic Devices Using Ultrasound”, Polym. Eng. Sci., 45, 606612 (2005)10.1002/pen.20310Search in Google Scholar

Pape, J., “Grundlagen der Prozesssimulation von Einschneckenkonzepten zur Hochleistungsplastifizierung”, PhD Thesis, Padderborn (2006)Search in Google Scholar

Pearson, J. R. A., “On the Melting of Solids near a Hot Moving Interface. With Particular Reference to Beds of Granular Polymers”, Int. J. Heat Mass Transfer., 19, 405411 (1976)10.1016/0017-9310(76)90096-XSearch in Google Scholar

Potente, H., “An Analytical Model of Partial and thorough Melting in Single Screw Extruders”, Int. Polym. Proc., 6, 297303 (1991)10.3139/217.910297Search in Google Scholar

Praher, B., Straka, K. and Steinbichler, G., “An Ultrasound-Based System for Temperature Distribution Measurements in Injection Moulding: System Design, Simulations and Off-Line Test Measurements in Water”, Meas. Sci. Technol., 24, 084004 (2013)10.1088/0957-0233/24/8/084004Search in Google Scholar

Rauwendaal, C.: Polymer Extrusion, Hanser, 4th Ed., Munich (2001)10.1002/0471440264.pst126Search in Google Scholar

Tadmor, Z., Gogos, C. G.: Principles of Polymer Processing, 2nd Edition, Wiley-Interscience, New Jersey (2006)Search in Google Scholar

Tadmor, Z., Klein, I.: Engineering Principles of Plasticating Extrusion, Van Nostrand Reinhold, New York (1970)Search in Google Scholar

Tadmor, Z., Duvdevani, I. J. and Klein, I., “Melting in Plasticating Extruders – Theory and Experiments”, Polym. Eng. Sci., 7, 198217 (1967)10.1002/pen.760070313Search in Google Scholar

Tadmor, Z., “Fundamentals of Plasticating Extrusion”, Polym. Eng. Sci., 6, 185190 (1966)10.1002/pen.760060303Search in Google Scholar

Vermeulen, J. R., Gerson, Ph. M., Beek, W. J., “The Melting of a Bed of Polymer Granules on a Hot Moving Surface”, Chem. Eng. Sci., 26, 14451455 (1971)10.1016/0009-2509(71)80064-7Search in Google Scholar

Wang, D., Min, K., “Inline Monitoring and Analysis of Polymer Melting Behavior in an Intermeshing Counter-Rotating Twin-Screw Extruder by Ultrasound Waves”, Polym. Eng. Sci., 45, 9981010 (2005)10.1002/pen.20364Search in Google Scholar

Received: 2014-03-03
Accepted: 2014-05-20
Published Online: 2014-11-04
Published in Print: 2014-11-30

© 2014, Carl Hanser Verlag, Munich