A numerical simulation study of mold filling in the injection molding process
1Cologne University of Applied Sciences (TH Köln), Group for Computational Mechanics and Fluid Dynamics, Steinmüllerallee 1, 51643 Gummersbach, Germany.
2Cologne University of Applied Sciences (TH Köln), Group for Computational Mechanics and Fluid Dynamics, Steinmüllerallee 1, 51643 Gummersbach, Germany.
DOI:
https://doi.org/10.7494/cmms.2021.1.0743
Abstract:
Injection molding can undoubtedly be regarded as one of the most widely used manufacturing processes for polymers (Guevara-Morales & Figueroa-Lopez, 2014). Furthermore, injection molding has found its way into various branches of industry (Fernandez et al., 2018) since it has several essential advantages over other processing techniques in terms of good surface finish, the ability to process complex parts without the need for secondary operations, and low cost for mass production. In order to find optimal process settings, it is necessary to gain a deeper insight into the filling process and the underlying physical phenomena, as well as a thorough understanding of the complex material behavior. In this context, the numerical simulation of the injection molding process is increasingly important. Therefore, the current contribution is dedicated to present a thorough comparative numerical study for the mold filling of an exemplary thin-walled mold geometry, including a realistic non-Newtonian viscosity model for the polymer melt. For the numerical simulation, the authors employ the commercial CFD software packages Cadmould 3D-F and ANSYS CFX. While ANSYS CFX is a well-established CFD software for numerical modelling of multiphysical phenomena, Cadmould 3D-F is a highly specialized and computationally efficient alternative suitable for certain geometric configurations in the context of injection molding. The present study is new in the sense that it demonstrates the equivalence of the considered software packages for the simulation of the injection molding process in thin-walled mold
geometries.
Cite as:
Baum, M., & Anders, D. (2021). A numerical simulation study of mold filling in the injection molding process. Computer Methods in Materials Science, 21(1), 25-34. https://doi.org/10.7494/cmms.2021.1.0743
Article (PDF):
Keywords:
Injection molding, Polymers, Hele-Shaw approximation, Computational fluid dynamics, Computing methods
References:
Cardozo, D. (2009). A brief history of the filling simulation of injection moulding. Journal of Mechanical Engineering Science, 223(3), 711–721. https://doi.org/10.1243/09544062JMES986.
Chiang, H.H., Hieber, C.A., & Wang, K.K. (1991). A Unified Simulation of the Filling and Postfilling Stages in Injection Molding. Part I: Formulation. Polymer Engineering and Science, 31(2), 116–124. https://doi.org/10.1002/pen.760310210.
Fernandez, C., Pontes, A.J., Viana, J.C., & Gaspar-Cunha, A. (2018). Modelling and optimization of the injection-molding process: a review. Advances in Polymer Technology, 37(2), 429–449. https://doi.org/10.1002/adv.21683.
Guevara-Morales, A., & Figueroa-López, U. (2014). Residual stresses in injection molded products. Journal of Materials Science, 49, 4399–4415. https://doi.org/10.1007/s10853-014-8170-y.
Haagh, G.A.A.V., & Van De Vosse, F.N. (1998). Simulation of three dimensional polymer mould filling processes using a pseudo concentration method. International Journal for Numerical Methods in Fluids, 28(9), 1355–1369.
Hele-Shaw, H.S. (1899). The Motion of a Perfect Liquid. Proceedings of the Royal Institution of Great Britain, 16, 49–64.
Hieber, C.A. (1987). Melt viscosity characterization and its application to injection molding. In A.I. Isayev (Ed.), Injection and Compression Molding Fundamentals (pp. 124–129). Marcel Dekker.
Hieber, C.A., & Shen, S.F. (1980). A Finite-Element/Finite-Difference Simulation of the Injection-Molding Filling Process. Journal of Non-Newtonian Fluid Mechanics, 7(1), 1–32. https://doi.org/10.1016/0377-0257(80)85012-9.
Kaiser, J.-M., Arab, A., & Stommel, M. (2012). Device to Determine Rheological Properties of Thermoplastics Blended with Chemical Foaming Agent. Zeitschrift Kunststofftechnik / Journal of Plastics Technology, 8, 91–105.
Karrenberg, G., Neubrech, B., & Wortberg, J. (2013). CFD-Simulation der Kunststoffplastifizierung in einem Extruder mit durchgehend genutetem Zylinder und Barriereschnecke. Zeitschrift Kunststofftechnik / Journal of Plastics Technology, 12(3), 205–238. https://doi.org/10.3139/O999.04032016.
Mukras, S.M.S., & Al-Mufadi, F.A (2016). Simulation of HDPE Mold Filling in the Injection Molding Process with Comparison to Experiments. Arabian Journal for Science and Engineering, 41(5), 2847–2856. https://doi.org/10.1007/s13369-015-1970-9.
Nielsen, L.E., & Landel, R.F. (1994). Mechanical Properties of Polymers and Composites. Marcel Dekker.
Osswald, T.A., & Rudolph, N. (2015). Polymer rheology. Fundamentals and applications. Hanser Publications.
Rezayat, M., & Stafford, R.O. (1991). A thermoviscoelastic model for residual stress in injection molded thermoplastics. Polymer Engineering and Science, 31(6), 393–398. https://doi.org/10.1002/pen.760310602.
Rusdi, M.S., Abdullah, M.Z., Mahmud, A.S., Khor, C.Y., Abdul Aziz, M.S., Abdullah, M.K., Yusoff, H., & Firdaus, S.M. (2014). Numerical Investigation on the Effect of Injection Pressure on Melt Front Pressure and Velocity Drop. Applied Mechanics and Material, 786, 210–214. https://doi.org/10.4028/www.scientific.net/AMM.786.210.
Rusdi, M.S., Abdullah, M.Z., Mahmud, A.S., Khor, C.Y., Abdul Aziz, M.S., Ariff, Z.M., & Abdullah, M.K. (2016). Numerical Investigation on the Effect of Pressure and Temperature on the Melt Filling During Injection Molding Process. Arabian Journal for Science and Engineering, 41(5), 1907–1919. https://doi.org/10.1007/s13369-016-2039-0.
Simcon Kunststofftechnische Software GmbH (2004). Simulation of fluid flow and structural analysis within thin walled three dimensional geometries, European Patent Application, EP 1385103 A1.
Studer, M., & Ehring, F. (2013). Reduktion von Formteilverzug beim Spritzgießen durch optimale Wanddickenverteilung – Eine Machbarkeitsstudie. Zeitschrift Kunststofftechnik / Journal of Plastics Technology, 9, 209–252.
Studer, M., & Ehring, F. (2014). Minimizing Part Warpage in Injection Molding by Optimizing Wall Thickness Distribution. Advances in Polymer Technology, 33(S1), 21454. https://doi.org/10.1002/adv.21454.
Wang, W., Li, X., & Han, X. (2012). Numerical simulation and experimental verification of the filling stage in injection molding. Polymer Engineering and Science, 52(1), 42–51. https://doi.org/10.1002/pen.22043.
Zhang, J., Yin, X., Liu, F., & Yang, P. (2016). The simulation of the warpage rule of the thin-walled part of polypropylene composite based on the coupling effect of mold deformation and injection molding process. Science and Engineering of Composite Materials, 25(3), 593–601. https://doi.org/10.1515/secm-2015-0195.