Air pollutant emissions from multi jet fusion, material-jetting, and digital light synthesis commercial 3D printers in a service bureau

Abstract

As additive manufacturing becomes more prevalent in industrial manufacturing facilities, so does human interaction with these machines. In this study, we characterized the size-resolved concentrations of particulate matter (PM, from ≈ 11 to 20,000 nm in size) and volatile organic compounds (VOC) resulting from a material-jetting (Projet 5500X), multi jet fusion (HP MJF 4200), and photopolymerization (Carbon 3D continuous liquid interface production). During all processes, PM concentrations were below the OSHA limits and ultrafine PM (PM0.1) concentrations were well below levels commonly observed for fused deposition modeling printers. PM and total volatile organic compound (VOC) concentrations during printing were close to background levels for the HP MJF printer and HP MJF post processing station. However, the mean particle size of the powder used (PA 12) was above the upper detection limit of the instrument (20 μm). Carbon 3D total VOC levels were highest during part post processing. Cyclic PM emissions from the Projet 5500X printer suggested higher PM emissions during cooling fan activity. VOC analysis revealed high concentrations of HP ink solvents (2-Pyrrolidinone and Triethylene glycol), potential exposure to fluorinated compounds and photoresin VOCs during Carbon 3D post-processing, and exposure to photo-resin compounds during Projet 5500X printing. This study indicates that proper exhaust and facility air exchange can limit concentrations of PM and VOCs and therefore particular attention to the building design and ventilation system should be taken into consideration for additive manufacturing facilities to mitigate potential human exposure and associated health risks.