Title: Shrink Controlled, Thermoset 3D Print Media for Use with Customized Large-Scale Printers

Authors: Robert M. Adams, Blaze A. Heckert, Richard J. Pauer, Michael A. Mathews

DOI: 10.33599/nasampe/s.22.0841

Abstract: During 3D printing of metals and plastics, internal stresses are created in the part during the cooling process. Cooling occurs along a predictable gradient based on mass, specific heat of the media, and ambient temperatures. As cooling parts contract, warpage often occurs that requires active mitigation, such as heating of print bed and/or print space, use of rigidized print base, and the application of a chemical adhesion promoter to the base. These measures add cost and time to the additive process.

This presentation will discuss alternative ways to improve the dimensional stability of 3D printed molds during initial cure and downstream molding processes using thermoset media. Mitigation of shrinkage will be shown as it relates to epoxy modified ester-based media, entropy, fiber selection, extenders, and printer control. Examples will be presented that contrast degrees of deformation, its cause, and options to reduce it.

References: [1] See USPTO, WO 2020243714 A1 [2] https://aquila.usm.edu/cgi/viewcontent.cgi?article=1083&context=masters_theses [3] Omnexus.specialchem.com/polymer-properties/properties/coefficient-of-linear-thermal-expansion [4] Tezvergil, A., Lippo L. , Vallittu, P. “The effect of fiber orientation on the thermal expansion coefficients of fiber-reinforced composites” Dent Materials. 2003 Sep;19(6):471-7. doi: 10.1016/s0109-5641(02)00092-1 [5] Jiang, D., Smith, D. “Anisotropic mechanical properties of oriented carbon fiber filled polymer composites produced with fused filament fabrication” Additive Manufacturing, Volume 18, December 2017, Pages 84-94 [6] ORNL/TM-2014/334 [7] Curbell Plastics website: https://www.curbellplastics.com/Research-Solutions/Resources/Articles/PEEK-vs-Ultem-PEI [8] Raney, Jordan R. “Rotational 3D printing of damage-tolerant composites with programmable mechanics”, PNAS February 6, 2018 115 (6) 1198-1203; first published January 18, 2018; https://doi.org/10.1073/pnas.1715157115 [9] Magnum Venus Products, Mike Kastura: https://www.mvpind.com/

Conference: SAMPE 2022

Publication Date: 2022/05/23

SKU: TP22-0000000841

Pages: 15

Price: $30.00