Prevention through design: insights from computational fluid dynamics modeling to predict exposure to ultrafine particles from 3D printing

ABSTRACT

Fused filament fabrication (FFF) 3D printers are increasingly used in industrial, academic, military, and residential sectors, yet their emissions and associated user exposure scenarios are not fully described. Characterization of potential user exposure and environmental releases requires robust investigation. During operation, common FFF 3D printers emit varying amounts of ultrafine particles (UFPs) depending upon feedstock material and operation procedures. Volatile organic compounds associated with these emissions exhibit distinct odors; however, the UFP portion is largely imperceptible by humans. This investigation presents straightforward computational modeling as well as experimental validation to provide actionable insights for the proactive design of lower exposure spaces where 3D printers may be used. Specifically, data suggest that forced clean airflows may create lower exposure spaces, and that computational modeling might be employed to predict these spaces with reasonable accuracy to assist with room design. The configuration and positioning of room air ventilation diffusers may be a key factor in identifying lower exposure spaces. A workflow of measuring emissions during a printing process in an ANSI/CAN/UL 2904 environmental chamber was used to provide data for computational fluid dynamics (CFD) modeling of a 6 m² room. Measurements of the particle concentrations in a Class 1000 clean room of identical geometry were found to pass the Hanna test for agreement between model and experimental data, validating the findings.

KEYWORDS:

• 3D printer emissions
• additive manufacturing
• ultrafine particles
• indoor air quality
• computational fluid dynamics
• exposure

Acknowledgments

This material is based upon work supported by the USACE Engineer Research and Development Center Environmental Laboratory under Contract No. W912HZ18C0024 to NanoSafe, Inc. (Blacksburg, VA). Any opinions, findings and conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the USACE Engineer Research and Development Center. Construction of the stainless steel ANSI/CAN/UL 2904 chamber was supported by the National Institute of Environmental Health Sciences of the National Institutes of Health under Award Number R43ES030650. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. M. Hull acknowledges the support of Virginia Tech’s Institute for Critical Technology and Applied Science (ICTAS). This work used shared facilities at the Virginia Tech National Center for Earth and Environmental Nanotechnology Infrastructure (NanoEarth), a member of the National Nanotechnology Coordinated Infrastructure (NNCI), supported by NSF (ECCS 1542100).

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Additional information

Funding

This work was supported by the Engineer Research and Development Center [W912HZ18C0024]; National Institute of Environmental Health Sciences [R43ES030650]; National Nanotechnology Coordinated Infrastructure, NSF [ECCS 1542100].