Abstract
Bulk molding compounds (BMC) are short fiber reinforced polyester molding compounds and mostly processed by injection molding. They consist essentially of polyester resin, styrene, additives, fillers and glass fibers and are fabricated in a conventional Z-kneader by mixing the resin and the solid fillers. Due to its doughy and moist consistency BMC requires force feeding to the barrel of the injection molding machine by a piston or screw stuffer. Furthermore, the raw material has a limited shelf life and needs special storage conditions. Because of the considerable proportion of volatile styrene, the dwell time of the material during processing is an important parameter. In this study the styrene loss is quantified during the injection molding production with a screw stuffer and evaluated for different loading scenarios. As a result, an assistance machine function is developed which optimizes the load operation in order to reduce the impact of styrene loss.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
References
AVK – Industrievereinigung Verstärkte Kunststoffe e. V.: Handbuch Faserverbundkunststoffe/Composites: Grundlagen, Verarbeitung, Anwendung. Springer, Berlin (2014)
Palik, M.: Vernetzte Präzision. Kunststoffe 98(4), 83–85 (2009)
Späth, M., Zillmer, M., Karlinger, P., Schemme, M., Gehde, M.: Einfluss des zeitabhängigen Materialzustands beim Spritzgießen von rieselfähigen, duromeren Formmassen auf den Prozess und die Bauteileigenschaften. In: 25. Technomer Conference, Chemnitz (2017)
Schemme, M.: Sicherung der Produktqualität bei der Herstellung und Verarbeitung von SMC Werkstoffen. Dissertation, Universität Erlangen-Nürnberg (1996)
Lafranche, E., Cilleruelo, L., Ryckebusch, M., Krawczak, P.: A novel adaptive process control for injection moulding of BMC and CIC polyester compounds. Adv. Compos. Lett. 14(5), 151–161 (2005)
Domininghaus, H.: Kunststoffe: Eigenschaften und Anwendungen. Springer, Berlin (1988)
Funke, V.W., Knödler, S., Feinauer, R.: Prüfung der Gültigkeit der Copolymerisationsparameter zur Berechnung der Zusammensetzung von Copolymerisaten vernetzter Polyesterharze bei hohen Umsätzen. Makromol. Chem.: Macromol Chem. Phys. 49(1), 52–61 (1961)
Bureau, E., Chebli, K., Cabot, C., Saiter, J.M., Dreux, F., Marais, S., Metayer, M.: Fragility of unsaturated polyester resins cured with styrene: influence of the styrene concentration. Eur. Polym. J. 37(11), 2169–2176 (2001)
González-Romero, V.M., Macosko, C.W.: Viscosity rise during free radical crosslinking polymerization with inhibition. J. Rheol. 29(3), 259–272 (1985)
Yang, Y.S., Suspene, L.: Curing of unsaturated polyester resins: viscosity studies and simulations in pre-gel state. Polym. Eng. Sci. 31(5), 321–332 (1991)
Stevenson, J.K.: Free radical polymerization models for simulating reactive processing. Polym. Eng. Sci. 26(11), 746–759 (1986)
Lee, L.J.: Curing of compression molded sheet molding compound. Polym. Eng. Sci. 21(8), 483–492 (1981)
Blanc, R., Agassant, J.F., Vincent, M.: Injection molding of unsaturated polyester compounds. Polym. Eng. Sci. 32(19), 1440–1450 (1992)
Pusatcioglu, S.Y., Fricke, A.L., Hassler, J.C.: Heats of reaction and kinetics of a thermoset polyester. Polym. Eng. Sci. 24(4), 937–946 (1979)
Yousefi, A., Lafleur, P.G., Gauvin, R.: Kinetic Studies of Thermoset Cure Reactions: A Review. Polym. Compos. 18(2), 157–168 (1997)
Kia, H.G.: Sheet Molding Compounds: Science and Technology. Hanser, München (1993)
Burns, R.: Polyester molding compounds. Taylor & Francis, Abingdon (1982)
Hill, R.R. Jr., Muzumdar, S.V., Lee, L.J.: Analysis of volumetric changes of unsaturated polyester resins during curing. Polym. Eng. Sci. 35(10), 852–859 (1995)
Bartkus, E.J., Kroekel, C.H.: Low shrink reinforced polyester systems. Appl. Polym. Symp. 15, 113–135 (1970)
Li, W., Lee, L.J.: Low temperature cure of unsaturated polyester resins with thermoplastic additives: I. dilatometry and morphology study. Polymer 41(2), 685–696 (2000)
Bucknall, C.B., Davies, P., Partridge, I.K.: Phase separation in styrenated polyester resin containing a poly (vinyl acetate) low-profile additive. Polymer 26(1), 109–112 (1985)
Boyard, N., Vayer, M., Sinturel, C., Erre, R., Delaunay, D.: Modeling PVTX diagrams: application to various blends based on unsaturated polyester—Influence of thermoplastic additive, fillers, and reinforcements. J. Appl. Polym. Sci. 92(5), 2976–2988 (2004)
Delahaye, N., Marais, S., Saiter, J.M., Metayer, M.: Characterization of unsaturated polyester resin cured with styrene. J. Appl. Polym. Sci. 67(4), 695–703 (1998)
European Community Official Journal, Council Directive 1999/13/EG
Zwecker, J., Schreiner, H.: BASF SE: Low-evaporation polyester resins. US Patent 5,132,343 (1992)
Hunold, D., Wobbe, H.: Spritzgießen und Vernetzen. Kunststoffe 3(90), 38–42 (2000)
Meixner, F., Brams, P., Schultheis, S.: Vorrichtung zum Beschicken von Spritzgieß- und Extrudiereinheiten, EP0470510 B1 (1995)
Drummer, D., Schiffers, R., Topic, N., Kruppa, S.: Stabilization of BMC injection molding by process control measures. SPE Antec, Orlando, 1537–1542 (2018)
Jazbinsek, A.: Zuführvorrichtung für eine Extruderschnecke. DE102011122935B3 (2011)
Rehmet, P.: Ein Duroplast in der Spritzgießmaschine. K-Zeitung 4 (2017)
Acknowledgement
The presented investigations take place within the research project “Quality-optimized Production of Thermosets”, which is supported by the Bavarian Ministry of Economic Affairs and Media, Energy and Technology within the cluster “Neue Werkstoffe (BayNW)”. The cooperation partners are University of Applied Sciences Rosenheim, Deckerform Produktionssysteme GmbH and Gubesch Thermoforming GmbH. The authors acknowledge the input and support of the cooperation partners, the promoter as well as the Project Management Jülich.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer-Verlag GmbH Germany, part of Springer Nature
About this paper
Cite this paper
Topic, N., Kruppa, S., Drummer, D. (2020). Assistance Machine Function for BMC Injection Molding. In: Hopmann, C., Dahlmann, R. (eds) Advances in Polymer Processing 2020. Springer Vieweg, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-60809-8_15
Download citation
DOI: https://doi.org/10.1007/978-3-662-60809-8_15
Published:
Publisher Name: Springer Vieweg, Berlin, Heidelberg
Print ISBN: 978-3-662-60808-1
Online ISBN: 978-3-662-60809-8
eBook Packages: EngineeringEngineering (R0)