Title: Extrusion Deposition Additive Manufacturing Utilizing High Glass Transition Temperature Latent Cured Epoxy Systems
Authors: John Lindahl, Christopher Hershey, Gary Gladysz, Vinay Mishra, Karana Shah, and Vlastimil Kunc
Abstract: This paper investigates the formulation, chemo-rheological properties, and extrusion deposition additive manufacturing (AM) of high glass transition temperature epoxies. Currently there are two methods of using thermoset materials in extrusion deposition AM. The first approach uses a reactive material that will fully cross-link during the build process. The second approach, which is explored in this paper, uses a reactive material that requires a thermal curing cycle after deposition is completed. Yield stress fluids for successful deposition were produced by blending various ratios of rheology modifying fillers into latent curing epoxy systems. After analyzing the rheological properties of the various blends via shear, temperature, and cure rate, the preferred formulation was selected. Test specimens for flexural analysis and dynamic mechanical analysis were printed from down selected combinations. This work resulted in the identification of key parameters for printing latent cured epoxy systems that will be scaled for the first large scale 3D printed epoxy for composite tooling applications.
References: 1. Raney JR, Compton BG, Mueller J, Ober TJ, Shea K, Lewis JA. “Rotational 3D printing of damage-tolerant composites with programmable mechanics.” Proceedings of the National Academy of Sciences. 2018:201715157. https://doi.org/10.1073/pnas.1715157115 2. Hmeidat NS, Kemp JW, Compton BG. “High-strength epoxy nanocomposites for 3D printing.” Composites Science and Technology. 2018;160:9-20. https://doi.org/10.1016/j.compscitech.2018.03.008 3. Lewis, J.A., “Direct Ink Writing of 3D Functional Materials.” Advanced Functional Materials, 2006. 16(17): p. 2193-2204. DOI: 10.1002/adfm.200600434 4. Kunc, Lee, Mathews, Lindahl, et al., “Low Cost Reactive Polymers for Large Scale Additive Manufacturing.” CAMX 2018 Proceedings. Dallas, TX; 2018. 5. Rios, O., et al., “3D printing via ambient reactive extrusion.” Materials Today Communications, 2018. 15: p. 333-336. https://doi.org/10.1016/j.mtcomm.2018.02.031 6. Romberg, S.K., et al. “Large-Scale Additive Manufacturing of Highly Exothermic Reactive Polymer Systems.” Sampe 2019, Charlotte, NC, May 20-23, 2019. Society for the Advancement of Material and Process Engineering. 7. Duty C, Ajinjeru C, Kishore V, Compton B, et al., “A Viscoelastic Model for Evaluating Extrusion -Based Print Conditions.” Solid Freeform Fabrication 2018. Austin, Tx; 2018. 8. Love, L.J., et al., “The importance of carbon fiber to polymer additive manufacturing.” Journal of Materials Research, 2014. 29(17): p. 1893-1898. https://doi.org/10.1557/jmr.2014.212 9. Duty CE, Drye T, Franc A. “Material Development for Tooling Applications Using Big Area Additive Manufacturing (BAAM).” Oak ridge National Laboratory (ORNL); Manufacturing Demonstration Facility (MDF); 2015. Web. doi:10.2172/1209207. 10. Vlastimil Kunc, Ahmed Arabi Hassen, John Lindahl, Seokpum Kim, Brian Post, Love L. “Large Scale Additively Manufactured Tooling For Composites.” 15th JAPAN International SAMPE Symposium and Exhibition. Japan: SAMPE; 2017. 11. Mishra, V. (July 30, 2018). “Technical Data on Dixie Anhydride Prototypes for CRADA on 3D Printing Using Epoxy-Anhydrides.” [Technical Memorandum]. Pasadena, TX. 12. ASTM Standard D790-15, 2016, “Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials” ASTM International, West Conshohocken, PA, 2016. DOI: 10.1520/D0790-15E02
Conference: SAMPE 2019 - Charlotte, NC
Publication Date: 2019/05/20
Price: FREEGet This Paper