Reducing ultrafine particulate emission from multiple 3D printers in an office environment using a prototype engineering control

Abstract

Recent studies have shown that high concentrations of ultrafine particles can be emitted during the 3D printing process. This study characterized the emissions from different filaments using common fused deposition modeling printers. It also assessed the effectiveness of a novel engineering control designed to capture emissions directly at the extruder head. Airborne particle and volatile organic compound concentrations were measured, and particle emission rates were calculated for several different 3D printer and filament combinations. Each printer and filament combination was tested inside a test chamber to measure overall emissions using the same print design for approximately 2 h. Emission rates ranged from 0.71 × 10 7 to 1400 × 10 7 particles/min, with particle geometric mean diameters ranging from 45.6 to 62.3 nm. To assess the effectiveness of a custom-designed engineering control, a 1-h print program using a MakerBot Replicator+ with Slate Gray Tough polylactic acid filament was employed. Emission rates and particle counts were evaluated both with and without the extruder head emission control installed. Use of the control showed a 98% reduction in ultrafine particle concentrations from an individual 3D printer evaluated in a test chamber. An assessment of the control in a simulated makerspace with 20 printers operating showed particle counts approached or exceeded 20,000 particles/cm 3 without the engineering controls but remained at or below background levels (< 1000 particles/cm 3 ) with the engineering controls in place. This study showed that a low-cost control could be added to existing 3D printers to significantly reduce emissions to the work environment.

PM2.5 decadal data in cold vs. mild climate airports: COVID-19 era and a call for sustainable air quality policy

“…3 Daily average a particle number density of condensable particles near Montreal Airport as measured by a CPC before lockdown and during lockdown. The PM 2.5 limit of exposure of 2 × 10 4 particles/cm 3 is represented by a different color (Dunn et al 2020 ; IFA 2012 ; Van Broekhuizen et al 2012 ); b PM 2.5 near Montreal Airport before lockdown and during lockdown; and c an example of back-trajectory analysis for the observation of condensable particles as given in Fig. 3a, in a location near the airport of Montreal on the 25 October 2019 and 14 February 2020, during the sampling period.…”

“…The WHO recommends an annual mean exposure limit to PM 2.5 of 10 μg/m 3 and a 24-h mean exposure of 25 μg/m 3 (WHO 2018 ). The exposure limit to airborne particles varies; for example, in Germany, the recommended workplace health threshold is 2 × 10 4 particles/cm 3 (Dunn et al 2020 ; IFA 2012 ; Van Broekhuizen et al 2012 ). Figure 3a illustrates that the particle concentration during the lockdown drops to 2 × 10 4 particles/cm 3 .…”

Use of Wood in Additive Manufacturing: Review and Future Prospects

“…Therefore, indoor air quality must be closely monitored, and it is strongly recommended that the 3D printer be used only in a well-ventilated environment [ 96 ]. Nevertheless, the development of ventilation options and guidance for the safe use of 3D printers in various environments, including a low-cost exhaust hood (equipped with a high-efficiency particulate air (HEPA) filter and an activated carbon filter), should be a priority [ 97 ].…”

State of the art in additive manufacturing and its possible chemical and particle hazards—review

“… 108 , 131 , 151 , 158 Similarly, different parameters are used to describe particle emissions, for example, average particle number concentrations, particle yield defined as the ratio of a particle emission metric (number, mass, surface area) to the mass of filament consumed or the mass of the printed object or particle number emission rates depending on calculation methods and standardized for printing time, mass, or length of the fiber used. 106 , 121 , 123 , 136 , 140 , 148 , 159 In addition, assumptions of particle influxes and losses during the experiment are used to calculate particle number emission rates values. According to Byrley, 148 particle losses through unaccounted leakages, outflow, settling, adhering to chamber walls, and agglomeration are considered together or separately depending on the test.…”

“…Some examples of limitation of the possible exposure of the printer's user can be found in the reviewed studies. For instance, Dunn et al 159 evaluated a low‐cost control that could be added to existing 3D printers (FDM type) to effectively reduce emissions to the work environment. Kwon et al 166 recommended the use of low‐emission materials for 3D printing also based on FDM technology as well as lower melting temperatures of the filaments.…”