Make Covid Stop: Making medical equipment, together

Custom fit no-sew T-shirt face mask on a Glowforge (or with scissors)

I spent the day today prototyping a new face mask design with my wife and kids. It’s loosely inspired by the research here:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3373043/
and here:
https://academic.oup.com/annweh/article/54/7/789/202744
which seems to indicate that T-shirts are a good candidate for filter media, and that the key challenge with homemade masks is the seal around the edges. This design uses a custom fit based on the length of the ear straps, the amount of material rolled down the top, and the tightness of the ties, to accomplish a better seal.

I am sharing it here to solicit improvements. Subjectively it seems to have an excellent seal, provides moderate resistance when breathing, stays in place during regular activity, and is comfortable to wear. I’d love suggestions for how to improve it - please make any changes you think would help and post your results in this thread.

This is prototype #35.

Video instructions:

Files:

tshirt mask-1-02.zip (4.0 KB)

You can drag and drop these into the Glowforge UI. Here’s where on the shirt you print them.

And for fun, a few pictures from R&D:



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Thanks so much for this dan, I’ve got a sewn one on the way but this will make a nice stop gap until it gets here. It it works well I’ll turn all my undersized t-shirts into them for coworkers as we can’t work from home.

One thing I think will improve this is to cut the filter from HIPA filter vacuum cleaner bags.

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When they fit test employees in the hospital to determine what size N95 mask they need (or whether, like me, they have a weird face and have to wear a PAPR instead) they put a hood over our head with the mask on, and puff artificial sweetener into it with a bulb. If you can taste any sweetness, your mask doesn’t fit right.

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Anyone else having that problem?

Is this PDF better?
tshirt mask-1.pdf (96.1 KB)

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The SVG from the zip opened fine for me but the PDF seems to only contain the filters.

I hear through the grapevine that 500 power / full speed works well for t-shirt fabric, if anyone is wondering about that. :slight_smile:

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It should be the max width that you can cut. (Plus or minus a fraction of an inch should be fine).

Correct! Also note that this is missing the filter piece inserts. I’ll work on getting a better PDF and SVG later today.

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Yeah, the filter pieces were there on the previous files, so I didn’t include them. :slight_smile:

A trick I have used a lot lately is to spray a sheet of cardboard or draft board with 3m contact adhesive and let it dry. It’s then slightly tacky and will hold light weight material like fabric and paper and keep it from blowing away. You can reuse it several times.

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beautiful simplicity! I’m going to give this a shot this evening.

These are amazing! Now I get how the folded part fills in the space around your nose to help block air there, which is genius, and the whole thing is very comfortable to wear. Thanks for your development work! Gkid is very excited about painting tiger stripes on hers. :wink:

For others: I do advise washing them before wearing them anywhere, lest you be overwhelmed by the smell of smoke!

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WOW! That’s interesting to know, Geek2Nurse. “Sam”

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Updated the files, added instructional video. Thank you @Geek2Nurse for helping fill this out! The current design can get two masks and filter sets (6 filters/mask) from a single men’s large T-shirt.

Be sure to put it through the washing machine when you’re done, or it’ll smell like lasers. :slight_smile:

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I serendipitously had just completed masks for us when we had to take Hubs to the ED last night (for non-COVID-related issues; thankfully he was the only one there, and they got him fixed up and he’s doing fine). Gkid’s mask had been washed and dried already, but mine was fresh out of the GF. I normally like the smell of woodsmoke (reminds me of my grandma’s house!) but I can now testify that breathing it up close like that gets old pretty quickly!

I gave this design a try last night, and it was the best/easiest fit homemade mask I’ve tried yet! Going out i usually need to forego wearing glasses because everywhere becomes foggy. This design created an excellent seal .

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I just sent four of these to friends last night - both kid size (test fitted by my kids) and adult size. Be sure to use all-cotton tees and launder before use!

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Have refactored the file for Affinity and made a jig to position and hold down fabric. Some more iteration to do but can shares if desired.

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One concrete change I made was to rotate the ear holes about 30 degrees to better match natural alignment.

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Brilliant! I would love it if you shared - the hold down is a fantastic idea.

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Zip with my files attached here. This includes the Affinity source file and PDF exports that I used to cut the jig and mask.

Changes. Apart from a bit of sizing change, I rotated the ear holes and added an option cut line to the bottom since I am experimenting with fabric where I don’t have the bottom seam.

Instructions. My jigs rely on the pins in the honeycomb you see in the photo above. This way they can be swapped in and out without doing any positioning work in the GF UI. Once you cut the jig/hold-down from a sheet of something you can put it on top of the fabric like a puzzle, then lift out the middle piece to leave the hold-down correctly positioned. The tolerances are little tighter than I might like ATM but it was fine last night.

I do expect to continue to iterate so can post updates.

tshirt_mask_1_0.zip (48.5 KB)

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