March 8 – 12, 2020
This paper investigates the formulation, chemo-rheological properties, and extrusion deposition additive manufacturing (AM) of high glass transition temperature (Tg) epoxies. Currently there are two methods of using thermoset materials in extrusion deposition AM. The first approach uses a reactive material that fully cross-links 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, needed for successful deposition, were produced by blending various ratios of rheology modifiers and other solids 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 were scaled for the first large scale 3D printed epoxy for composite tooling applications.
Gary Gladysz, Christopher Hershey, John Lindahl, Karana Shah, Alejandrina Campanella, and Vlastimil Kunc, "Extrusion deposition additive manufacturing utilizing high glass transition temperature latent cured epoxy systems" in "Innovative Materials For Additive Manufacturing (IMAM)", Daniel Schmidt, Luxembourg Institute of Science and Technology, Luxembourg Nikhil Gupta, New York University, USA Chua Chee Kai, NTU, Singapore Brett G. Compton, University of Tennessee, USA Eds, ECI Symposium Series, (2020). https://dc.engconfintl.org/imam/19