We worked with our local hospital to successfully fit-test these designs.

Table of Contents
Section ---- Contents
1 ------------ Licencing Information
2 ------------ Summary of Mask Variations
3 ------------ Zip File Contents\Necessary Files for Each Variation
4 ------------ Filter Material Link
5 ------------ Materials/Tools Needed

With proper post-print assembly and materials, this mask design can pass a fit test.

Section 1. Licencing Information

This design is posted with the following license: Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)

You are free to:

• Share — copy and redistribute the material in any medium or format
• Adapt — remix, transform, and build upon the material

Under the following terms:

Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. NonCommercial — You may not use the material for commercial purposes. ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.

Full legal code:https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode

Section 2. Summary of Mask Variation

There are three variations available:

• Press Fit
• 2T
• 1T

'T' Stands for 'Thread'. The only difference between 2T and 1T is that 2T has two threads. This is simply easier to start threading and makes a more even seal.

1T is included in this post so replacement parts are available for those currently using it.

2T and 1T use the exact same 'MaskDisk' and 'CapDisk'. These disks are included in each zip file as outlined in Section 2.

The Mask Hook is not included in any of the zip files but is a nice accessory if desired. It is designed for 3mm elastic cord.

All mask designs can be custom fit by applying heat to plastic and molding. Getting too hot will ruin the integrity of the mask.

Section 3. Zip File Contents\Necessary Files for Each Variation

Each zip file contains the necessary STL files for the assembly of its respective mask.

Press Fit zip Includes the following files:

• PressMask
• PressCap

2T zip includes the following files:

• 2TMask (apply foam around edge to ensure seal and comfort)
• 2TCap_Solid (for vacuum testing to ensure proper seal; Use with a tight fit O-Ring)
• 2TCap (for actual usage after seal ensured)
• MaskDisk (soldered and hot glued to mask orifice)
• CapDisk (Used to separate filter materials - only if multiple filters used)

1T zip includes the following files:

• 1TMask (apply foam around edge to ensure seal)
• 1TCap_Solid (for vacuum testing to ensure proper seal; Use with a tight fit O-Ring)
• 1TCap (for actual usage after seal ensured)
• MaskDisk (soldered and hot glued to mask orifice)
• CapDisk (Used to separate filter materials - only if multiple filters used)

Section 4. Filter Material Link

For filter material - use this New York Times article for reference.

https://www.nytimes.com/article/coronavirus-homemade-mask-material-DIY-face-mask-ppe.html#click=https://t.co/6I9AwrbvxI

The article mentions that air filters with MERV rating higher than 12 or Microparticle Performance Rating (MPR) of 1900. With these materials we have been cutting 70mm diameter circles to place inside the mask.

Section 5. Materials/Tools Needed

Materials needed for all mask variations:

• Some form of elastic to hold the mask on the face. (e.g. hairbands, thin sweatband, etc...)
• A closed-cell foam to seal the mask to the face. (Weatherstripping)
• Hot Glue/Hot glue gun to connect foam to contour of mask. It is advisable to cut a slit in the weatherstripping to place around the edge of the mask. The hot glue does not stick well to the adhesive that comes on the foam so this slit exposes raw foam to stick to

For 2T and 1T:

• Soldering Iron. This is used to solder the MaskDisk to the Mask. The raised edge of the MaskDisk should be heated with the iron and melted onto the wall of the mask. Be careful to not melt the wall of the mask as that will ruin the seal of the mask.

References

In the design of this mask, the facial contour from the Montana Mask found here:

https://www.makethemasks.com/3d-printing

was used.