(Remove the "XXXXXX' in the youtube video links below.)
I am about to make some masks for a small medical facility use, per this video (pattern, directions). I bought 12 HEPA cloth vacuum bags to be delivered Wednesday. I don't yet know what the breathability will be. The duckbill shape offers more flow surface area than a flat mask.
(We are going to use tie straps rather than elastic.)
This article documents the filtration capabilities & flow characteristics of various fabrics. (Tea towels = dish towels. I believe this to be this are not the linen variety.)
This article echoes the filtration capabilities per the above article. Of interest is that doubling a dish towel gives effective filtering to be equivalent to a surgical mask. Doubling other tested fabric didn't help much.
This article measures the filtration effect of DIY masks, as worn. They do seem to be effective.
JoAnn Fabrics has a lot of support for this, and there are tons of other designs & how tos all over the net. Note that you want to avoid using pins during construction.
Lots of people are making these. JoAnn Fabrics indicates their "partners" have made 28M masks of a goal of 100M.
Our local NextDoor indicate a tailor in downtown Los Altos is selling some at $8.
An issue is sanitizing. After looking at the possible sterilazation mechanisms (beyond discard & use new) for home use, I think I would choose to heat the mask to 170 degrees for 30 minutes. Consider that when choosing your materials. That is one of the reasons we aren't using elastic. (I do not know how the HEPA cloth will respond to that. Follow the iink for lower temps & longer times that work.
I also considered the ease of putting on & off the mask without touching the front of the mask. The original elastic design on the vacuum bag mask above looks to me to be difficult to put on without touching the front of the mask.
Another mask design that I thought was interesting, but has a bad flaw IMO, is this one The problem is that when you untie the straps, the outer, dirty part of the mask falls onto your chest, now making your shirt dirty.
I am about to make some masks for a small medical facility use, per this video (pattern, directions). I bought 12 HEPA cloth vacuum bags to be delivered Wednesday. I don't yet know what the breathability will be. The duckbill shape offers more flow surface area than a flat mask.
(We are going to use tie straps rather than elastic.)
This article documents the filtration capabilities & flow characteristics of various fabrics. (Tea towels = dish towels. I believe this to be this are not the linen variety.)
This article echoes the filtration capabilities per the above article. Of interest is that doubling a dish towel gives effective filtering to be equivalent to a surgical mask. Doubling other tested fabric didn't help much.
This article measures the filtration effect of DIY masks, as worn. They do seem to be effective.
JoAnn Fabrics has a lot of support for this, and there are tons of other designs & how tos all over the net. Note that you want to avoid using pins during construction.
Lots of people are making these. JoAnn Fabrics indicates their "partners" have made 28M masks of a goal of 100M.
Our local NextDoor indicate a tailor in downtown Los Altos is selling some at $8.
An issue is sanitizing. After looking at the possible sterilazation mechanisms (beyond discard & use new) for home use, I think I would choose to heat the mask to 170 degrees for 30 minutes. Consider that when choosing your materials. That is one of the reasons we aren't using elastic. (I do not know how the HEPA cloth will respond to that. Follow the iink for lower temps & longer times that work.
I also considered the ease of putting on & off the mask without touching the front of the mask. The original elastic design on the vacuum bag mask above looks to me to be difficult to put on without touching the front of the mask.
Another mask design that I thought was interesting, but has a bad flaw IMO, is this one The problem is that when you untie the straps, the outer, dirty part of the mask falls onto your chest, now making your shirt dirty.