(392a) High Strength, High Toughness Parts Via Dual Material Fused Filament Fabrication

Previous research in the field of bicomponent thermoplastic 3D printing material showed promise in developing structures with tough, near-isotropic properties; a feat that is unheard of in tradition fused filament fabrication (FFF) systems. The combination of a core with a significantly higher glass transition temperature (T_g) than the sheath allows for parts that can be annealed to increase chain diffusion across layers while maintaining dimensional stability. The use of a thermal draw tower in previous research allowed for rapid prototyping of material and geometric combinations, but lacks viability as a larger scale manufacturing process due to the bottleneck of creating dual material preforms and requiring secondary processing. Using a convention coextrusion technique, with an additive manufacturing driven iteration process, showed promise as a scale-up technique, and was able to produce larger quantities of consistent filament needed for more comprehensive analysis and production. Compared to current state of the art ABS filaments, this filament showed a 5 time increase in z- direction impact toughness, and a 3 time increase in z-direction tensile strength after annealing. The enhanced thermal stability of this material allowed for higher print temperatures which also significantly improved strength. This research continues to demonstrate the groundbreaking improvements to FFF that are possible through dual material filaments as well as the manufacturing feasibility of such a product.