Written by: Jason Gomez, Quality Control Specialist
3D Printed Masks
In order to stymie the spread of COVID-19, people around the world have been rushing to supplement PPE supplies. While some individuals took to sewing fabric masks, the maker community decided to take it a step further. Using 3D modeling softwares and following the parameters outlined by the ECDC and CDC, individuals created models for masks, valves, and medical equipment that could easily be reproduced using most commercially available 3D printers. All of these designs were created to be wholly open-sourced, meaning that they were free to use, reproduce, and modify to the end users extent. Due to this, each of these open-source designs is fairly unique in their makeup, however all follow the same basic principle: to expand the utilization of limited or readily available resources for the safety of the user. An example of this would be the cutting of a surgical mask into smaller pieces. A standard surgical mask (when expanded) can be cut into six, 2.5 inch, squares. Each of these squares can then be used as a filter for a reusable mask, allowing the user to effectively and efficiently stretch the use of what would otherwise be considered single-use PPE. In addition to stretching resources, many other individuals have taken to creating masks which adapt either readily available or more obscure materials. These range from simple cotton pads to micro-HEPA filters used for robotic vacuum cleaners.
3D Printer Masks
Regardless of the means of filtration, each mask continually follows the same basic design and function. Most of these masks can be produced using relatively cheap FDM 3D printers, which work by continuously laying down thin-layers of plastic onto a heated bed. The material most frequently utilized for this is a corn-starch derived bioplastic known as polylactic acid (PLA.) This material is non-toxic, food safe, and is readily biodegradable. Once the material has been heated and melted into layers, the process is then repeated hundreds of times over, using a “sliced” version of the initial model. However this takes a very long time to do so. 3D printing as a process is ultimately barred by time. One of the most popular 3D printable masks, simply known as the “Montana Mask,” utilizes the 2.5 inch cut filter method listed above. However, while it is efficient, the mask itself takes more than 6 hours to produce on a standard FDM printer. In an effort to speed the process up, makers have taken to continuously redesigning and changing existing models. Some have been made to utilize thinner wall thicknesses, while others have been flattened completely so that they can be shaped and folded to match the contours of the user’s face. It’s this constant flux and evolution of design that truly highlights human ingenuity and resourcefulness in a time of crisis.
Making My Own Mask
I chose to test out several different masks that could utilize either cut N95 masks, vacuum bags, or cotton pads as their primary means of filtration. I began with the “Montana Mask” due to its popularity and ease of use. After producing one of these, I chose against making a large number. This was simply due to the scarcity of possible filters and the amount of time and materials needed to do so. I eventually settled on a different design that had been adapted several times over, and only took about 3.5 hours to completely produce. This design utilized a hard, yet moldable, shell and had a locking socket on the front which holds round cotton-pads that act to filter the air entering the mask. The ease of access and efficiency of the filtering means together produced a highly efficient and accessible means of PPE. Over a week’s time I made 17 masks. Each mask was sealed using an adhesive foam weatherstrip on the interior, and all were then shipped or dropped-off with family and friends. Once these first masks had made it to their current owners, I was able to acquire two more kilograms of filament, thanks to a friend. These resources will be dedicated to printing additional masks and face shield brackets for local hospitals and medical first responders.
Making a 3D Printed Mask at Home
If you have a 3D printer and would like to make your own at home you’ll need PLA filament, the print file, and something to use as a filter. PLA filament can typically be found on Amazon and most home improvement stores. If you’d like to use the print file that I used, it can be found here: NanoHack Mask. If you’d like to use the Montana Mask or check out some other designs, you can find links to those resources below. For the filter, I would recommend a surgical mask, MERV 16 air filter, or a vacuum cleaner bag/filter.
Good luck, and stay safe!
Montana Mask Link: https://www.makethemasks.com/3d-printing
Other Open Source print files: https://www.thingiverse.com/search?q=covid-19+mask&type=things&sort=relevant