General / Off-Topic Engineering Question about masks


That device above is a humidifier for oxygen supplies, costing under 2$.
It attaches to the green comfortable plastic mask, which is washable and reusable.
Example mask:

If we put a filter element in it, and stick on rubber flap exhaust valves to the cheap plastic mask, we would have a reusable comfortable respirator made from readily available gear, that comes already made in various sizes.

No medical personnel has to go without a medical grade reusable device again.

How would you do it?
 
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Sounds good in theory the issue is a decent seal to your face (be cleanshaven), which isn't that important in a medical oxygen mask and a seal to ensure incoming air is actually going through the filtering material instead of going around your filter inside the housing.

Military masks have changeable filters and need changing regularly, once a day is the absolute maximum they can go to IIRC. So you'd need to be able to change the filtering material and be sure it was sealed after the change.

If you exert yourself in any way you'll need more oxygen so airflow might exceed what it can do. I'd test it out at home with no filtering materiel before tackling that.
 
It ought to be easy to add another elastic strap and run a silicone bead or Sugru round the rim of the mask to make it airtight.

I was thinking a HEPA grade vacuum cleaner bag would be good for the filter.

If there was a high risk task to do, like an intubation of a sick victim, it could hook up easily to a compressed air cylinder, say a pressurized schedule 40 2 inch PVC pipe with end caps and a valve, and no filter would even be needed.
 
My main concern would be the filter element . Afaik, P3 Filters are needed, "active carbon" filtering not necessary ( not sure whether that is the correct term ) . Effective filtering based on particle size/particle filtering .

Maybe Dyson Vacuums could be used, or their Filters ? Or we look at the filter membranes used in reverse osmosis water purifying Systems ?
 
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Nearly 40000 surgical masks stored at the Guyana Space Center of Kourou were stolen, said the Cayenne public prosecutor.

I wonder how we can break into the space center of Kourou ?
 
It might be better to apply the KISS principle to this (keep is simple).

This could be a good idea and seems fairly simple, old sheets should do it use a drawer string if you lack elastic. Make a handful and boil wash them at night :

 

A study published today in JAMA compared the ubiquitous surgical (or medical) mask, which costs about a dime, to a less commonly used respirator called an N95, which costs around $1. The study reported "no significant difference in the effectiveness" of medical masks vs. N95 respirators for prevention of influenza or other viral respiratory illness.
"This study showed there is no difference in incidence of viral respiratory transmission among health care workers wearing the two types of protection," said Dr. Trish Perl, Chief of UT Southwestern's Division of Infectious Diseases and Geographic Medicine and the report's senior author. "This finding is important from a public policy standpoint because it informs about what should be recommended and what kind of protective apparel should be kept available for outbreaks
 
The internet man...for every study showing one thing, you can find another showing the exact opposite XD .


Also:

While a surgical mask may be effective in blocking splashes and large-particle droplets, a face mask, by design, does not filter or block very small particles in the air that may be transmitted by coughs, sneezes, or certain medical procedures. Surgical masks also do not provide complete protection from germs and other contaminants because of the loose fit between the surface of the face mask and your face.
I am starting to sift through the enormous list of resources I collected during the last 2, 3 weeks, to hopefully be able to write up somethng comprehensive on the issue of masks...soon™ .
 
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Never bothered to dig into this before.

Compared to parents not wearing masks, parents wearing surgical masks had 27% odds of getting the flu versus 24% wearing N95 masks (called “P2” masks here).
Difference not statistically significant. Confirmed by multiple studies. Some gave advantage to the cheap mask.

A doubled dishtowel works as well as the surgical mask material, 97% blockade of virus. Linen sucks. Plain cotton T Shirt isn't bad.

It is illogical that a badly fitted surgical mask with a gap big enough to stuff in your little finger, stops viral infections as well as a tight N95 mask. But it does empirically.
Obviously the protection is NOT from the barrier to viruses. It's suggested that the point of the mask is to stop us from touching our faces, so if we just keep our hands in our pockets, it might work just as well.

I'm collecting some simple materials to see what we can make tomorrow. Dialysis nurse is going to need something. I have my own supply of surgical masks, but they are limited. Could repurpose the material as filters, but I want a washable reusable mask.

Definitely want an exhaust valve so at least breathing out is OK, and reduce water buildup in the filter, and foggy glasses.
 
Full face mask is the most comfortable to wear, they are also reusable but not cheap.

 
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Never bothered to dig into this before.

Difference not statistically significant. Confirmed by multiple studies. Some gave advantage to the cheap mask.

A doubled dishtowel works as well as the surgical mask material, 97% blockade of virus. Linen sucks. Plain cotton T Shirt isn't bad.

It is illogical that a badly fitted surgical mask with a gap big enough to stuff in your little finger, stops viral infections as well as a tight N95 mask. But it does empirically.
Obviously the protection is NOT from the barrier to viruses. It's suggested that the point of the mask is to stop us from touching our faces, so if we just keep our hands in our pockets, it might work just as well.

I'm collecting some simple materials to see what we can make tomorrow. Dialysis nurse is going to need something. I have my own supply of surgical masks, but they are limited. Could repurpose the material as filters, but I want a washable reusable mask.

Definitely want an exhaust valve so at least breathing out is OK, and reduce water buildup in the filter, and foggy glasses.
Particle size ?

Each SARS-CoV-2 virion is approximately 50–200 nanometres in diameter.
2019-nCoV also has enveloped virions that measure approximately 50–200 nm in diameter with a single positive-sense RNA genome.
 
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I've stitched one together from layers of old t-shirt using the template in the link I posted, not bad at all. A little badly fitting at the sides of the nose, but I added a couple of tacking stiches to pull the materiel tighter there and now its pretty well fitted.

Better than nothing and it'll stop me touching my face.
 
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We need to start looking at different materials . We need to start finding different methods/ways of production . The existing supply chains, based on their respective resources/production, are extremely strained already, and it will not become any better anytime soon . We need to start looking for alternatives that work . In the words of Ms. v. Kerkhoeve : The world is facing a severe shortage of PPE .
 
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I would not trust the facepiece . Also, P2 filters are not sufficient . Against viral threat, you need P3, better is to use P3 R . How easy is it to get replacement filters ? Cleaning/disinfecting the piece is also a concern . Sorry man .
It's ok, I bought it for sanding and for when I get time (or can be bothered!) to put a bit more loft insulation down!!
 
It's ok, I bought it for sanding and for when I get time (or can be bothered!) to put a bit more loft insulation down!!
Most of us will rarely get into a situation where we actually need this kind of protection . Its remarkably, depressingly simple to protect oneself from getting infected in most non-healthcare situations XD .
 
The Chinese are the No. 1 producer of masks in the world.

The virus started in this country (officially), then it spreads around the world.

Suddenly suspicion comes over me. :oops:

😷

(This is a science fiction story of course since Chinese exports are generally very degraded)
 
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