A Comparison of the physical properties of two commercial 3D printing PLA grades

Abstract

As desktop three-dimensional (3D) printing has gained popularity over a wide range of settings, the use of polylactic acid (PLA) has increased commensurately due to the perceived positive safety and environmental qualities of the material. Though there are currently several manufacturers of PLA for fused filament fabrication (FFF) platforms, Ingeo grade 4043D (NatureWorks, LLC, Minnetonka, MN, USA) is widely used amongst the 3D printing community. The work presented here compares two grades of commercially available PLA that have been marketed to the 3D printing community. Here, the former ‘gold standard’, PLA Grade 4043D, is compared to the newer grade, 3D870. Mechanical properties, rheological characteristics, chemical qualities, and the ability to manipulate the crystallinity of the material were compared between the two. A detailed fracture surface analysis of tensile specimens was also performed that revealed distinct differences in crack propagation behaviour between the two materials in the annealed and non-annealed conditions.

Keywords

• fused filament fabrication
• failure analysis
• polymer crystallinity
• mechanical testing
• fractography
• annealing