Re:Face Masks: Much More Than You Wanted to Know
by exabrial on Tuesday March 24, 2020 @12:25PM
(#22675954)
Side notes: I was trying to figure out how I could "help" by developing an N95 respirator with some online communities. I was prepared to be humbled by what I didn't know, but holy smokes, now I realize I can't even begin to know what I don't know.
* 3d printed PLA? Deforms at autoclaving temperatures. chemical sterilization not recommended b/c there's not many good ways to "know" it's worked correctly.
* Sealing? Good luck. There are some people working on using TPU to help seal, but again, sterilization is a problem.
* Porosity? 3d printed materials can barely pass 2psi. This also creates a LOT of places for bacteria to hide.
* Filter media? DO NOT cut up a HEPA filter! They're made with micron-scale fiberglass. This keeps getting suggested, but people don't realize that HEPA filters are not made of paper.
I'm confident an open source design and process can eventually be made, but it's much harder problem than it looks. There's a lot of people are adding a lot of noise (I'm in "read-only" mode for now to cut down on the noise level) so if you're thinking of contributing, the best thing you can do is just read atm.
Producing Face Shields has some interesting and unexpected requirements (head back leakage among other things), but is a much simpler problem to solve and there are some good designs (Google Prusa 3d Face Shield)
* 3d printed PLA? Deforms at autoclaving temperatures. chemical sterilization not recommended b/c there's not many good ways to "know" it's worked correctly.
* Sealing? Good luck. There are some people working on using TPU to help seal, but again, sterilization is a problem.
* Porosity? 3d printed materials can barely pass 2psi. This also creates a LOT of places for bacteria to hide.
* Filter media? DO NOT cut up a HEPA filter! They're made with micron-scale fiberglass. This keeps getting suggested, but people don't realize that HEPA filters are not made of paper.
I'm confident an open source design and process can eventually be made, but it's much harder problem than it looks. There's a lot of people are adding a lot of noise (I'm in "read-only" mode for now to cut down on the noise level) so if you're thinking of contributing, the best thing you can do is just read atm.
Producing Face Shields has some interesting and unexpected requirements (head back leakage among other things), but is a much simpler problem to solve and there are some good designs (Google Prusa 3d Face Shield)