Particle and vapor emissions from vat polymerization desktop-scale 3-dimensional printers

Abstract

Little is known about emissions and exposure potential from vat polymerization additive manufacturing, a process that uses light-activated polymerization of a resin to build an object. Five vat polymerization printers (three stereolithography (SLA) and two digital light processing (DLP) were evaluated individually in a 12.85 m 3 chamber. Aerosols (number, size) and total volatile organic compounds (TVOC) were measured using real-time monitors. Carbonyl vapors and particulate matter were collected for offline analysis using impingers and filters, respectively. During printing, particle emission yields (#/g printed) ranged from 1.3 ± 0.3 to 2.8 ± 2.6 × 10 8 (SLA printers) and from 3.3 ± 1.5 to 9.2 ± 3.0 × 10 8 (DLP printers). Yields for number of particles with sizes 5.6 to 560 nm (#/g printed) were 0.8 ± 0.1 to 2.1 ± 0.9 × 10 10 and from 1.1 ± 0.3 to 4.0 ± 1.2 × 10 10 for SLA and DLP printers, respectively. TVOC yield values (μg/g printed) ranged from 161 ± 47 to 322 ± 229 (SLA printers) and from 1281 ± 313 to 1931 ± 234 (DLP printers). Geometric mean mobility particle sizes were 41.1-45.1 nm for SLA printers and 15.3-28.8 nm for DLP printers. Mean particle and TVOC yields were statistically significantly higher and mean particle sizes were significantly smaller for DLP printers compared with SLA printers (p < 0.05). Energy dispersive X-ray analysis of individual particles qualitatively identified potential occupational carcinogens (chromium, nickel) as well as reactive metals implicated in generation of reactive oxygen species (iron, zinc). Lung deposition modeling indicates that about 15-37% of emitted particles would deposit in the pulmonary region (alveoli). Benzaldehyde (1.0-2.3 ppb) and acetone (0.7-18.0 ppb) were quantified in emissions from four of the printers and 4-oxopentanal (0.07 ppb) was detectable in the emissions from one printer. Vat polymerization printers emitted nanoscale particles that contained potential carcinogens, sensitizers, and reactive metals as well as CONTACT A. B. Stefaniak,

Progressive 3D Printing Technology and Its Application in Medical Materials

“…The main reason is the specific fabrication process and raw material to meet the high-quality requirements for medical devices. Four common AM techniques are powder-based printing (Brunello et al, 2016), vat polymerization-based printing (Stefaniak et al, 2019), droplet-based printing (Graham et al, 2017), and extrusion-based printing (Taylor et al, 2018).…”

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

“…VAT polymerization printers (SLA—stereolithography, DLP—digital light processing technologies) emitted nanoparticles containing potentially carcinogenic, allergenic, and reactive metals and carbonyl vapors. The observed differences in emissions between printers/technologies suggest that the technology used is an important factor in reducing exposure to harmful particles in the air [ 50 ]. Inhalation of fumes and organic particles containing metals is possible even when using 3D printing toys intended for children.…”

Estimates of particulate matter inhalation doses during three‐dimensional printing

“…A number of studies have addressed the hazardous substances emitted during 3D printing, but most have focused on exposure‐associated indices, such as airborne concentration and emission rate. A few studies have reported about respiratory deposition of particle emissions released during 3D printing to date, 22‐27 but it is necessary to evaluate the inhalation exposure levels focusing on the particle emission level and size distributions in detail. Some studies provided proportional deposition in each respiratory region using a multi‐path particle dosimetry (MPPD) model.…”

“…Some studies provided proportional deposition in each respiratory region using a multi‐path particle dosimetry (MPPD) model. Stefaniak and colleagues have attempted to estimate lung deposition and provided average proportional deposition of particles emitted from carbon nanotube containing filaments (FDM printing) and liquid feedstock resins (vat polymerization printing) in head airway, tracheobronchiolar, and pulmonary regions 23,24 . In another study, only deposition fraction of particles emitted from children's 3D pen and toys was estimated using the MPPD model 25 .…”