Particle Emission and Metal Composition Characterizations for Fused Filament Fabrication 3D Printers Using Emerging Materials

QIAN ZHANG, Rodney J. Weber, Todd Luxton, Derek Peloquin, Eric Baumann, Marilyn Black, UL Research Institutes

     Abstract Number: 196
     Working Group: Indoor Aerosols

Abstract
Fused filament fabrication (FFF) 3D printers have been gaining popularity and are widely used in non-industrial indoor environments. Studies have shown FFF 3D printing emits ultrafine particles and have indicated it as an emerging source of micro- and nano-plastics. However, as the 3D printing market is growing rapidly with continuously emerging technologies and materials, characterization of particle emissions from new materials such as composite filaments is needed. Particularly for filaments containing metal composites and/or additives, the potential of releasing metals in emitted particles is not well known. In this study, we utilized a standardized chamber study method to characterize particle emissions from various pure polymer and composite filaments. We measured particle size distributions using a scanning mobility particle sizer and an optical particle sizer and calculated particle emission factors for each print condition. In addition, we collected particle filter samples and analyzed them for metal composition using inductively coupled plasma mass spectrometry. Metal composition of raw filaments was also analyzed. We found that metal composite filaments generated a different trend in particle size distributions from polymer and polymer composite filaments, where metal composite filaments generated lower particle number but higher particle mass emissions. By comparing the metal composition in the raw filaments and emitted particles, we identified some metals associated with filament additives were enriched in the particles, while metals associated with metal powder composites were less likely to transfer into particle emissions. In addition, we found that the printer itself can be a source of metal emission in particles. Overall, FFF 3D printing emits high levels of ultrafine particles containing metal components, which could potentially pose a health concern when inhaled.