Particle and volatile organic compound emissions from a 3D printer filament extruder

Abstract

Fused Deposition Modeling (FDM®), also known as Fused Filament Fabrication (FFF), 3D printers have been shown in numerous studies to emit ultrafine particles and volatile organic compounds (VOCs). Filament extruders, designed to create feedstocks for 3D printers, have recently come onto the consumer market for at-home hobbyists as an alternative to buying 3D printer filaments. These instruments allow for the creation of 3D printer filaments from raw plastic pellets. Given the similarity in processes and materials used by 3D printers and filament extruders, we hypothesized that filament extruders may also release ultrafine particle emissions and VOCs. An off-the-shelf filament extruder was operated in a 2 m 3 chamber using three separate feedstocks: acrylonitrile butadiene styrene (ABS) pellets, pulverized poly-lactic acid (PLA), and PLA pellets. Ultrafine particle emissions were measured in real-time using a scanning mobility particle sizer and thermal desorption tubes were used for both non-targeted and targeted analysis of VOCs present in emissions. Ultrafine particle number emission rates were comparable to those found in 3D printer studies with the greatest to least emission rates from ABS pellets, pulverized PLA, and PLA pellets, respectively. In addition, the majority of particles released were found to be ultrafine (1-100 nm), similar to 3D printer studies. A variety of VOCs were identified using the ABS feedstock, including styrene and ethylbenzene, and PLA feedstock. Styrene average mass

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

“…So far, there are some gaps in the literature data on emissions and exposure associated with working with 3D printers. Although exposure may occur during material processing 136 or after processing of manufactured parts, only a few studies include data related to these tasks, as confirmed by Zisook and col. 109 . Another important issue is different ways to calculate, for example, TVOC value from the results of an analysis, making published TVOC data often not comparable.…”

“…The studies are conducted under various conditions, that is, in test chambers or real working spaces of different cubature and ventilation systems, some of which take into account such parameters as particle deposition on surfaces 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.…”

“…So far, there are some gaps in the literature data on emissions and exposure associated with working with 3D printers. Although exposure may occur during material processing 136 or after processing of manufactured parts, only a few studies include data related to these tasks, as confirmed by Zisook and col.. 109 Another important issue is different ways to calculate, for example, TVOC value from the results of an analysis, making published TVOC data often not comparable. The problem is not only the lack of guidance on which compounds should be considered in the procedure for calculating TVOC values as their sum, 45 but also the conditions under which the measurements were conducted, which can significantly affect the final result.…”

“… 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.…”

“… 165 However, for non‐industrial amateur 3D printing, such solutions are not usually used. A study of a commercially available 3D printer filament extruder for personal use by Byrley et al 136 evaluated emissions of large amounts of ultrafine respirable particles and various volatile organic compounds, which may pose additional exposure to 3D printer hobbyists who also use such a printer. Moreover, the spread of 3D devices for domestic purposes may pose a threat not only to the people using them, but also to other household members (including children).…”