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VAF caps, COVID19 and Effective Mask

Ed_Wischmeyer

Well Known Member
Saw the doctor a few days back who said that you could make an effective mask using four layers of sweatshirt material. Regular towels have too coarse a weave, and she was unimpressed with my suggestion of shop towels.

Four layers of sweatshirt is a bit heavy for a mask, but since lots of us wear baseball caps anyway, a VAF cap (or equivalent) can provide a force in the Nz direction, or, if you prefer, lift vector. I made a kind of cowboy mask that attached to the cap and then safety pinned the four layers of sweatshirt material to the front of it. There are any number of ways to pull the mask back towards your face (increased drag vector), depending upon what you've got on hand and how you implement the mask.

Ugly, clunky, cumbersome but a small price to pay.

Be safe, be well, wash your hands.


Moderator - yes, a little off topic but all things considered...
 
Take care doing this. While 4 layers of cotton T-shirt or sweatshirt material may approach the filtering equivalency of an N95 mask, the effort required to breathe through a single layer of fabric is about double that of an N95 mask. Four layers later, you're up to about 16x that of an N95 mask. If it isn't, you're not breathing through the fabric (ie. air is leaking around the edges).

It's been shown that those who wear N95 masks regularly in their profession suffer from reduced lung capacity due to the extra effort of breathing through the mask. Wearing something that's 16x harder to breathe through is going to make it much worse.

You don't need to come up with something that's as good as an N95 mask to be safe. For the average public, a single layer mask that prevents your spray from reaching others is what you're looking for. If everyone wore them, nobody would need an N95.
 
Also, from my physician SO who is making a few of those 'protect others' masks, you do not want to use a knit fabric (t-shirts, sweats, etc.), but a woven one (bandanas, for example). She's been doing two layers with a layer of flannel in between. I was thinking I'd have her use an old VAF shirt when she gave me that news. Now I'm thinking I'll have to have a custom bandana made up.
 
COVID is primarily spread by droplets.

The purpose of these masks is to prevent sick people from spreading droplets when they cough / sneeze (this is why we put masks on patients), and to keep droplets from sick people from contacting your mucous membranes (why everyone else should wear a mask).

The size of the virus is (relatively) unimportant in these use cases.

Wear a mask when in public. Don't touch your face (the mask also helps remind you of this). And WASH YOUR HANDS or use hand sanitizer.

I am an ER doc. I wear a simple surgical mask when seeing patients during this pandemic (except for certain procedures and situations that require an N95 / additional PPE, but these do not apply generally when out in public).

Be safe...
 
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