Characterization and Control of Nanoparticle Emission during 3D Printing

Abstract

This study aimed to evaluate particle emission characteristics and to evaluate several control methods used to reduce particle emissions during three-dimensional (3D) printing. Experiments for particle characterization were conducted to measure particle number concentrations, emission rates, morphology, and chemical compositions under manufacturer-recommended and consistent-temperature conditions with seven different thermoplastic materials in an exposure chamber. Eight different combinations of the different control methods were tested, including an enclosure, an extruder suction fan, an enclosure ventilation fan, and several types of filter media. We classified the thermoplastic materials as high emitter (>10 #/min), medium emitters (10 #/min -10 #/min), and low emitters (<10 #/min) based on nanoparticle emissions. The nanoparticle emission rate was at least 1 order of magnitude higher for all seven filaments at the higher consistent extruder temperature than at the lower manufacturer-recommended temperature. Among the eight control methods tested, the enclosure with a high-efficiency particulate air (HEPA) filter had the highest removal effectiveness (99.95%) of nanoparticles. Our recommendations for reducing particle emissions include applying a low temperature, using low-emitting materials, and instituting control measures like using an enclosure around the printer in conjunction with an appropriate filter (e.g., HEPA filter) during 3D printing.

Acute health effects of desktop 3D printing (fused deposition modeling) using acrylonitrile butadiene styrene and polylactic acid materials: An experimental exposure study in human volunteers

“…This seems to be particularly justified if long‐term exposures in special work places or the exposure of children and adolescents is involved. These measures may benefit from the detailed description of reduction strategies available in the literature …”

Effect of nozzle temperature on the emission rate of ultrafine particles during 3D printing

“…It is also possible that bed temperature could affect the emission of particles, although emissions were found to be largely unaffected by bed temperature in a previous study . There was a difference in the bed temperature used here compared with that of the previous study . When using laywood, experiments were performed at a bed temperature of 60°C in the previous study compared with 90°C in this study, and when using nylon, a temperature of 90°C was used in the previous study, while room temperature was used in this study.…”

“…Objects were printed by the 3D printer using four filament types: ABS, PLA, nylon, and laywood (Table ). These filaments were selected based on the manufacturer‐recommended operating temperature and emission rate, including a relatively low temperature (PLA and laywood; 215°C), low emissions (PLA and laywood), and relatively high temperature (ABS and nylon; 245°C) and medium (ABS) or high (nylon) emissions, as determined in our previous study . The same object a cube of 34.5 × 34.5 × 34.5 mm was made in each test using identical amounts filament (893 cm), and the time required was 135 ± 0.9 minutes.…”

“…A detailed description of the chamber, along with a schematic diagram, was provided in a previous publication. 10 In brief, clean air filtered through a high-efficiency particulate air (HEPA) filter and activated charcoal filter (ACF) was introduced into the front section during the experiment, and air in the chamber was exhausted through the HEPA filter at the end of the back section. The fan in the back section provided a steady air velocity of 0.1 m/s into the sampling chamber throughout the experiment and a flow rate of 1.5 m 3 /min at the sampling location.…”

“…9,21 Previous research studies have examined the effect of temperature under a few conditions, but it has not been systematically evaluated. 9,10,12,18,21,22 These studies provided characterizations of particle emissions under limited conditions and did not attempt to estimate the emission rates stage by stage at various temperature. Further, there is no specific attempt to estimate the slope of emission rates by different filament types and temperature conditions.…”