Effect of Print Speed on Airborne Plastic Emissions from Fused Deposition Modeling 3D Printing

JUSTIN MORROW, Alyssa Yerkeson, Xiangjing Gao, Jun Wang, University of Cincinnati

     Abstract Number: 131
     Working Group: Chemicals of Emerging Concern in Aerosol: Sources, Transformations, and Impacts

Abstract
Over the last 10 years, fused deposition modeling (FDM) 3D printing has become a fast, effective, and affordable method for creating plastic components from plastic filament. Emission studies have consistently found that FDM produces particulate aerosol that can vary in concentration by more than 5 orders of magnitude depending on process parameters and printed material. One understudied process parameter is printing speed – high speed printers released in the last two years now advertise maximum plastic extrusion rates of 30 – 50 mm³/s while the highest rate found in the literature is roughly 9 mm³/s. Therefore the two objectives of this study are (1) to develop standard methods for isolating the plastic extrusion rate and printing speed as key variables in FDM emission studies and (2) to apply these methods to study the impact of print speed on total aerosol exposure from high speed FDM 3D printing. A high speed 3D printer was operated with increasing speed of up to 22 mm³/s of commanded extrusion and emissions were measured by SMPS, OPS, and air quality monitors. The results showed aerosol mean particle size in the ultrafine range (< 100 nm) with concentration as high as 3.5×10⁵ cm^-3 and particle emission rate as high as 3x10¹¹ particles/hour – consistent with previous literature. However unlike previous literature, two experimental studies on emissions vs. speed both showed a nonlinear effect with the maximum emissions found roughly midway in the speed range. Initial calculations of particle yield per unit printed mass also indicated an overall reduction in specific particle yield with printing speed. Therefore we present that high speed printing can offset increased emission rate by lowering print time when printing a single object and that printing emissions (and therefore worker exposure) can be considered as a factor when setting FDM printing parameters.