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

Abstract

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.

3D Printing-Induced Fine Particle and Volatile Organic Compound Emission: An Emerging Health Risk

“…One reason is its easy handing, cost efficiency, and desktop-level capability. Furthermore, due to its thermal processing and thermoplastic raw materials [such as acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA)], FDM/FFF-type 3D printing relies on the extrusion and deposition of heated thermoplastic materials, which is a typical process that has been shown to generate significant particle emissions. − (3) Most studies of the characteristics of 3D printing emissions were based on laboratory simulations. − In these studies, the test environment normally consisted of small and independent chambers and all relevant parameters influencing 3D printer emission were controllable, so the simulated experiments can eliminate the impact of the surrounding environment. Figure presents the schematic diagram of laboratory simulation tests of desktop 3D printer particle emission, including the recommended detection parameters and common instrumentation.…”

Optimization of Extrusion-Based 3D Printing Process Using Neural Networks for Sustainable Development

“…Aerosol emissions from nanoclusters (NCA) can account for 9–48% of total emissions, so up to half of particulate emissions may have been previously overlooked [ 46 ]. Diffusivity and extrusion rate are considered the most important variables in predicting environmental concentrations in the near field [ 47 ]. The aforementioned computational model would be useful for estimating worker exposure and for determining whether respiratory protection is necessary.…”

Large-Format Additive Manufacturing and Machining Using High-Melt-Temperature Polymers. Part I: Real-Time Particulate and Gas-Phase Emissions

“…Variations of material extrusion AM include desktop-scale fused filament fabrication (FFF) "three-dimensional" (3-D) printers that are increasingly common in offices, libraries, schools, universities, and the home; 2 industrial-scale FFF machines used in workplaces for prototyping and production; 3 and large-format additive manufacturing (LFAM) machines used for production of tooling and other products. 4 LFAM machines differ from other types of ME technologies because they use a robot-or gantry-mounted nozzle to extrude layers of fiber-reinforced polymers at kg/h rates to build parts with dimensions that can exceed several meters in the x-, y-, and z-directions. 5 Desktop-scale FFF 3-D printers are limited to extrusion of filaments conducive to the temperature capability of the extruder nozzle and/or the machine design (e.g., could lack walls to provide the necessary stable thermal environment for some polymers).…”

“…3,23 To our knowledge, only one study has evaluated emissions from an LFAM machine, and that was during extrusion of ABS. 4 Several reports have been published that described adverse toxicological and human health effects associated with emissions from extrusion of ABS using desktop-scale FFF 3-D printers. 24−28 The potential for exposure (and possible adverse effects) from other polymers (including high-melt-temperature polymers) used in LFAM is less clear.…”

“…One type of AM process is material extrusion, in which a solid polymer is forced through a heated nozzle, melted, and deposited in successive layers on a build platform to form an object. Variations of material extrusion AM include desktop-scale fused filament fabrication (FFF) “three-dimensional” (3-D) printers that are increasingly common in offices, libraries, schools, universities, and the home; industrial-scale FFF machines used in workplaces for prototyping and production; and large-format additive manufacturing (LFAM) machines used for production of tooling and other products . LFAM machines differ from other types of ME technologies because they use a robot- or gantry-mounted nozzle to extrude layers of fiber-reinforced polymers at kg/h rates to build parts with dimensions that can exceed several meters in the x -, y -, and z -directions …”