The subject of potential health risks in relation to 3D printing has been mostly overlooked. However, this is beginning to change thanks, in no small part, to the efforts of 3DPrintClean, a USA-based manufacturer of safety enclosures for fused deposition modeling (FDM)/fused filament fabrication (FFF) and stereolithography (SLA) desktop 3D printers.
Founded in mid-2015 by the inventor of said enclosures, James Nordstrom, 3DPrintClean has since been on a mission to educate those industry sectors utilizing these printers on their potentially harmful emissions, namely ultrafine particles (UFPs) and volatile organic compounds (VOCs).
A lot of 3D printers incorporate a high-efficiency particulate air (HEPA) filter, although it needs to be borne in mind that these are only capable of capturing particles of 0.1μm or 300 nanometers and above in size and therefore not the UFPs that are 0.1μm or 100 nanometers and below.
3DPrintClean expects to begin shipping the latest models of its enclosures—the Model 660 and Model 870—in August, 2017. The only real difference between the two is size. The Model 660 is designed to house smaller, desktop-sized printers, affording internal dimensions of 600 (w) x 810 (h) x 600 (d) millimeters, and the Model 870 is for printers that have larger build platforms, measuring 810 (w) x 810 (h) x 810 (d) millimeters.
The Model 660 and Model 870 incorporate many new features requested by the owners of their predecessors. The most important of these are a significantly larger filter, more powerful blower motor and customized rubber gasket seals.
The filter on the new models is 19 x 19 inches, whereas on the previous models it was just 5 x 7 inches. Recommended usage of the 19 x 19-inch filter is one year, so considerably longer than the 90 days given for the 5 x 7-inch filter (these timescales are based on the printer being used on a daily basis, so c. 10-12 hours). It also goes without saying that a 19 x 19-inch filter is going to be considerably more effective at capturing UFPs and VOCs.
The filter comprises two filters, one for UFPs and the other for VOCs, that are custom produced one on top of the other. The enclosure performs a calendar year countdown from the date that the original filter is first used and notifies the user 30 days prior to its advised replacement.
A 150 CFM (cubic feet per minute) blower motor complements the larger filter, being three times as strong as the blower motor on the old enclosures and therefore capable of circulating the contaminated air more quickly. Together, the new filter and blower motor are said to reduce filtration times considerably.
The customized rubber gasket seals replace the previously used self-adhesive brush seals around both the door and pass-through points for the printer’s cables. This allows the enclosure to be made completely airtight, eliminating the possibility of UFPs and VOCs escaping, unless of course the door is opened.
3DPrintClean plans to send Model 660 to the Illinois Institute of Technology (IIT)—the university responsible for initially highlighting the issue of harmful emissions from 3D printing—for functionality testing. The IIT tested the previous corresponding model and confirmed its ability to filter out UFPs and VOCs. This time, it will be looking to verify that the aforementioned new features have increased overall efficiency.
The enclosures are described as ‘multi-pass’, a patent-pending term that refers to the contaminated air being recirculated and passed through the filter multiple times to clean it; a process commonly known as ‘scrubbing’. At each so-called pass, the filter captures and reduces the number of UFPs and VOCs in the enclosure.
Scrubbing is carried out throughout the print process and continues after the print is complete. A significant challenge though, and one that 3DPrintClean is making a concerted effort to overcome, is advising users of ‘the right time to open the door’ and remove their prints. There are numerous 3D printing materials available, not to mention those currently in development, and the time taken to filter out UFPs and VOCs is obviously not the same for them all.
3DPrintClean intends to carry out tests on all available 3D printing filaments, thus enabling it to recommend times for leaving finished prints inside the enclosures via the operator’s guide.
An increasing number of educational institutions, particularly in Canada, are standardizing on the use of PLA as it is said to emit less fumes than other materials. Nevertheless, some PLA filaments contain other materials such as acrylic, making them more of a concern.
A feature included on the enclosures at the request of PLA users is a dehumidifier cartridge. This means that reels of PLA filament can be held inside the enclosures on the spool holders provided. Like the filter cartridge, the dehumidifier cartridge has a useful life. It contains beads that can be seen through a clear window, and its recharging or replacement is advised once these beads turn a certain color.
Another notable improvement, albeit digressing somewhat from this article’s primary focus, is that the inside of the enclosures is kept at a constant temperature, thus helping to improve the quality of prints and prevent their cracking, curling or warping. Heat comes from several sources—e.g., the printer heads and enclosure lighting—and is distributed evenly by the blower motor and thanks to the rubber gasket seals’ elimination of drafts.
In the event that a printer overheats, the enclosures offer three lines of defense. The first is thermal cut off, allowing the user to set a maximum temperature that if exceeded, results in the stopping of power to the printer. The second is automatic fire suppression, so that if the printer begins to smolder and rises above 121˚C (250˚F), it is sprayed in ABC powder. The third is, of course, the enclosure itself, serving to contain the fire and prevent it from spreading.
The enclosures’ touchscreens can be used to adjust the enclosures’ filtration speed, lighting and thermal cut off as well as monitor their temperature and humidity.
To conclude then, the latest enclosure models offer a range of improvements that support 3DPrintClean’s primary objective—to protect 3D printer users’ health by preventing, or at least limiting, their exposure to VOCs and USPs. The majority of 3DPrintClean’s customers are currently in the public domain, specifically educational institutions and libraries, but the company is now looking to extend its reach into industrial markets.