Modeling Particle Emissions from Three-Dimensional Printing with Acrylonitrile-Butadiene-Styrene Polymer Filament.

An eddy diffusion model using data from a desktop three-dimensioanl (3D) printer was developed under laboratory conditions and then coupled with Monte Carlo analysis to estimate the potential range of particulate concentrations in and around various industrial-size 3D printers, in this case large additive manufacturing processes using acrylonitrile-butadiene-styrene polymer feedstock. The model employed mass emission estimates determined from thermal gravimetric analysis and printer enclosure particle loss rates. Other model inputs included ranging terms for extrusion rate, temperature, print time, source-to-receiver distance, printer positions, particle size fraction, and environmental diffusivity estimates based on air changes per hour. Monte Carlo analysis bracketed measured environmental particulate concentrations associated with large-scale additive manufacturing processes (3D printing). Statistically, there was no difference between the average near-field particle concentrations measured and that of the model-derived average. However, the model began to vary more statistically, if not practically, from air-monitoring results in the far field. Diffusivity and extrusion rate emerged as the two most important variables in predicting environmental concentrations. This model can be used to estimate air concentrations over a range of varying conditions, such as one might employ in a "what if" type of evaluation to estimate employee exposure, for example, as a compliance effort with OSHA standard 29 CFR Part 1910.132, requiring a formal hazard assessment for work environments as a "before exposure" effort to determine if respiratory protection is needed.