3D-Printed Masks

As of March 31, 2020 we are no longer printing our original mask (at the bottom of this page).
The masks we’ve already made WILL go in to use at local facilities.

PLEASE SEE OUR PROJECT UPDATE FOR MORE INFORMATION.

 

Please read the information about the safety of open-source PPE on this page.

Original Lowell Makes Mask Design – NO LONGER IN PRODUCTION AS OF MARCH 31, 2020

Files

Lowell Makes was 3D-printing this mask. This design was posted by lafactoria3d on March 16, 2020; they are not affiliated with Lowell Makes and we don’t have the original files. If Thingiverse isn’t loading, we have posted the files on DropBox and Google Drive.

We printed the pieces (2 sets per bed on Prusa’s) at .3 layer height and 5% infill.

PLA or PETG is fine. No ABS. The instructions say to use both PLA and PETG, but using one or the other for the entire print is fine.

Optional: You can add these 3D-printed elastic clips to adjust the elastic band. If you are giving masks to a local hospital, check if they will accept adjustable straps (some will not)

Seals

For sealing the edges, we are using weatherstripping foam (available at places like Ace HardwareHome DepotLowes). We have found that self-stick weatherseal, 3/4″ wide x 5/16″ thick, works best. To adhere, hot glue the sticky side of the foam to the edge of the mask, taking care to get the foam completely into the bridge of the nose.

Straps

We are using 1/4″ wide elastic straps from a craft supply store.

Filters

We conducted several tests with local hospitals for the best filter materials. Here is a summary of what we’ve learned so far about filter options:

  • We were originally looking at using clean-room vacuum bags and/or MERV-13 filters. We found that vacuum bags perform better than the MERV-13s, but they tear easily and are harder to source.
  • We also ordered some MERV-16, but when they arrived we immediately suspected they contained fiberglass, and our scanning electron microscope confirmed that. This was never tested in a mask. If you can find non-fiberglass MERV-16, it may perform well.  Do not use any material containing fiberglass for your filter. 
  • We have heard from another team at UF using a similar mask design that they had success in a fit test using surgical wrap.
  • Other options we’d like to try are
    • (1) a cut-up N95 mask (so you could potentially get 3-4 filters from one single-use mask)
    • (2) nonwoven polypropylene, which is used to make reusable grocery bags. We looked at the polypropylene under our scanning electron microscope and it looks very promising. We have not conducted a fit test yet.

Sanitizing masks

We are wiping all masks down with a bleach solution before delivering to healthcare facilities, where they will be professionally sanitized before use.
Note that rubbing alcohol will un-stick hot glue.

Assembly

In this video, one of our members assembles a mask and narrates the process.

Images of supplies: