Manufacturing Masks: how Technologists can Lend both Hands and Machines
3D printing and makerspace technologies present a unique opportunity to address the nationwide shortage of personal protective equipment, which is why UVA’s engineering department and hospital are currently collaborating on the development of 3D printable PPE. In addition, many community members with 3D printers are ready to get going as soon as designs are officially approved. Our own Scholar’s Lab and its Technologists are among those working toward using their 3D printing and modeling capabilities for the cause. In an effort to test the effectiveness of 3D-printed PPE, we printed a mask frame and attached a HEPA filter (typically meant for HVAC purposes) to it. The mask is both wearable and comfortable (after some sanding!). Listed below are instructions for the build, which only took a few hours.
Besides being eager to print masks, area residents are sewing them as well. Rectangular-shaped pieces of fabric are being used to make inexpensive masks in much less time than it takes to create higher-grade, surgical masks. A downside to these masks, though, is they’re more labor intensive than 3D masks: Someone has to be hands-on cutting and sewing; printing masks are mostly dependent on machines. So yes, the fabric masks might take less total time, but they require more worker time. Additionally, while fabric masks could cover more area on the face, they might not last as long, because they lack the respirator’s strength.
Through production of both, we found that one of the limitations of 3D printing is producing a strong enough mask seal. As you’ll see in our instructions, we’ve come up with suggestions for making the seal stronger by applying self-adhesive gasket material to the inside edge of the 3D mask.
Both masks have their pros and cons, but the main thing we learned is that there are a wide-range of willing people and available ways to help with the shortage of PPE. Anyone with a 3D printer or a sewing machine should consider donating their time and resources.
Instructions for 3D Printed Masks:
- Print the two attached .stl files using PLA plastic
- Sand the edges of the print
- Fasten elastic string, straps, chord, etc. as ties
- Place filter on the inside of the mask and push the smaller printed part into the larger mask, securing the filter
Photos of the final 3D printed project:
A more detailed set of instructions can be found here:
Directions-to-Make-3D-Printed-Mask.pdf
More 3D printable PPE Equipment:
- https://www.thingiverse.com/search?q=surgical+mask&type=things&sort=relevant
- https://www.sabinlab.com/operation-ppe
- https://www.npr.org/local/305/2020/04/01/825217523/people-are-3-d-printing-personal-protective-equipment-to-help-hospitals-with-shortage
Instructions for Sewed Mask:
Materials Needed:
- Two pieces of 12-inch-long and 7.25-inch-wide 100 percent cotton fabric (tight-weave cotton or quilted cotton). Using different colored fabrics would be useful to indicate inside and outside of the mask.
- One piece of 12-inch-long and 7.25-inch-wide interfacing or lightweight, breathable, stiff fabric.
- Fourteen inches of 1/8-inch flat elastic, stretch yarn or additional fabric for ties.
Instructions:
- Cut your pieces and mark all lines seen above.
- Fold fabric stack in half with the top layer on the inside so that you are stitching your triangular darts on the white/inside layer. Clip or pin together.
- Stitch one 1/2-inch dart on what will become the top of your mask — for your nose. Stitch another 3/4-inch dart on the other side for the chin. Note that these can be adjusted to be smaller or larger to fit the wearer.
- You can cut the darts open or press them flat.
- Sew the dotted line with a zig-zag stitch
- Fold the top and bottom edges (long sides) of the mask toward the inside along the marked seam allowance and press and pin or clip.
- Stitch on top of the fold to close. (This will leave a raw edge. You can finish your edges before sewing to finish if desired.)
- Fold the edges of your fabric tabs over 1/2 an inch or more and stitch 1/4 an inch from the edge to create a tunnel for the elastic. - Feed the elastic through the tunnel (a safety pin attached to one end will help with threading). Try on for size, and adjust the length as needed. Stitch or tie the ends of the elastic together.
Cotton mask design and instructions were sourced from: