Mechanical Evaluation of Additive Manufacturing Polymers for Cold Weather Environments, Including a Dual-Material Thermoplastic Elastomer Filament

Author(s):

Ryan M. Dunn, Kyle D. Olchewsky, Nikhil Patil, Jay H. Park, and Eric D. Wetzel

Abstract:

Izod testing is used to compare room temperature and cold temperature (–40 °C) impact strength for 3D-printed thermoplastic parts. Comparisons are made for in-plane (y-direction) and interlayer (z-direction) part orientations. The results show that all parts exhibit lower strength under cold conditions and for z-direction interfaces. However, acrylonitrile butadiene styrene (ABS) and Nylon 3D-printed parts show the lowest toughness values, while parts printed using polycarbonate and polybutylene terephthalate (PCPBT) and a dual material ABS+ thermoplastic elastomer (TPE) core-shell filament both show remarkably high toughness under cold conditions. In fact, these materials provide cold in-plane impact strengths that are nearly 10 times higher than a benchmark injection-molded Nylon part. PCPBT shows clear evidence of ductility even under cold conditions. Additional experiments attempt to apply a loop elastica test on 3D-printing filaments to characterize intrinsic cold toughness.