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3D Printed CoronaVirus Respirators

Posted: Mon Mar 23, 2020 4:24 pm
by jferguson
I've received offers from BangGood for N95 respirator masks at not-outrageous prices with 10 day delivery. I've had 100% good luck buying from them in the past, but mostly things where I understood exactly what I was going to get and had sufficiently controlled my expectations to cover minor disappointments - but never did have one.

We chose not to do this, because even if our buying these may not interrupt the supply chain to the medical folks who really need them, the neighbors would think it and probably shame us.

SO:

We've been making cloth masks from a pattern called FU MASK (mask, not a respirator) which is readily available online and is associated with websites which report effectiveness of various fabrics including whether doubling up layers makes any improvement (apparently not). It seems possible to reach 50% filtration in the particulate size range the virus particles occupy, which seems a lot better than Zero to me. And with fabric form an ordinary cotton undershirt.

A Chilean outfit which produces copper containing PLA filament which could itself be toxic to the virus has published STL files (NanoHack) which could produce the parts to make a respirator, one which you would have to provide the filter for.

https://cults3d.com/en/3d-printing/n95- ... emic-gora3

Ideally it would be made from their fiber, which of course appears to be universally sold out. I would think regular PLA while not "toxic" to the virus could be just as good, at least from a printing standpoint.

The mask itself is printed flat, must then be heated to 60C in a pan of hot water, and folded, (contoured?), to fit the face of the user. There is a flab which fits beneath the chin and two tabs which fit over the top of the nose piece and should be glued so the mask will retain its shape. the instructions are silent on the subject but it looks like some sealant could be added to prevent air leaks.

Is anyone here experimenting with this problem?

Re: 3D Printed CoronaVirus Respirators

Posted: Tue Mar 24, 2020 3:51 am
by Mach
Reddit says its bogus. https://www.reddit.com/r/3Dprinting/com ... egathread/

I'm working with a Houston Hackerspace to print visors. They're crowd sourcing (sewing?) masks with community support that I'm assuming is like the FU Mask. They're also working on a PAPR replacement but that's a big ask.

https://abc13.com/6040487/

Re: 3D Printed CoronaVirus Respirators

Posted: Tue Mar 24, 2020 6:41 pm
by jferguson
I don't think I'll bother with the mask referenced above. I don't like idea that it has to be warm molded to the face, and then glued and sealed if you don't want it to leak.

I'm going to make this one tomorrow:
https://longliveyoursmile.com/3d-printa ... -covid-19/

I like the looks of it, although I suspect that in this case, one size may not fit all, and because it's an stl file, I think I can only scale it up or down, not distort it to fit whoever of the two of us it doesn't fit by itself. Interesting question: does any of the mesh applications let you distort and save?

Janet is now making a few of the surgical mask types which admittedly are harder to seal against the face than respirators, but then with the filtration material we can get/make, we're only looking at 50% effectiveness at the virus particle size.

john

Re: 3D Printed CoronaVirus Respirators

Posted: Tue Mar 24, 2020 7:35 pm
by jferguson
It turns out that I can scale the mesh in all axes or symmetrically with Simplify3d. The website suggests this can be printed in 3 hours. best i can do is 6 using .2mm layers and PETG.

I don't think I'm going to make more than 2 of these things, so maybe that isn't a problem.

Re: 3D Printed CoronaVirus Respirators

Posted: Wed Mar 25, 2020 3:29 pm
by haithco1
Thanks for the great information. In addition to being a 3D printing enthusiast (I own a Makergear M3 ID), I'm a physician in practice at a 1000 bed hospital with multiple patients currently admitted for COVID-19. We have an acute shortage of masks (surgical masks, N95 masks, and related PPE equipment) so I plan on printing the model you linked to and see how it works. I just need to obtain the filter material and elastic bands to secure the masks to the head.

Thanks again for the info - I'll be curious to see how yours turns out after printing. I'm going to try PLA and maybe PETG (I'm awaiting a few PETG spools to be delivered soon).

Jeff

Re: 3D Printed CoronaVirus Respirators

Posted: Wed Mar 25, 2020 4:58 pm
by rpollack
Thank you all for posting. We are currently printing other parts for local hospitals. If you know of a need that is being unmet and 3d printing is the answer, let us know. We'll help print if we can and, if not, we'll help spread the word to people who can...

Be safe,
Rick

Re: 3D Printed CoronaVirus Respirators

Posted: Wed Mar 25, 2020 6:02 pm
by jferguson
Jeff,
I should add that my choice of PETG is not for its efficacy, to use a medical term of art, but because it's what's in the printer and I have (finally) a setup which produces consistent quality.

PLA could be a better choice.

If they lock down St Petersburg, I may not be able to get back to the printer which is in shop-space I rent.

My plan had been to make one and see how it fit each of us, scale as required, not forgetting that the filter grille needs to also be scaled. I may find that asymmetrical scaling works the best. but as I say, it may be a few days before i can get to it.

right now I'm contemplating the topology of nitrile gloves. Obviously the inside when worn should be clean especially with all the hand-washing, but once donned and exposed to the outer world, the outside must be assumed contaminated so on a return from outdoors, where do you take them off?

we've decided that the outside door and the path to the nearest to the door corner of the kitchen island should be considered outside. we drop any incoming packages on this corner, wipe them down with wipes, then take off the gloves, wipe the package and counter down, then do the 20 sec handwash.

at this point we don't trust anything. Amazon delivery guy told me they had two suspect cases at the warehouse - they were sent home. He wasn't clear on how they were discovered, his english was very challenging, but i think they are measuring temperatures as people show up for work - sort of what he implied but not sure. In any case, if this is true, this episode never made it to the news.

Re: 3D Printed CoronaVirus Respirators

Posted: Wed Mar 25, 2020 9:51 pm
by haithco1
Thanks John and Rick for the all information - it is extremely helpful. I plan to print this model in the next 48 hours (with PLA):

https://longliveyoursmile.com/3d-printa ... -covid-19/

If the printing is successful, I will reach out to the name referenced in the link and order the filter material they are using. It may or may not be as effective as the filters contained within the 3M N95 masks, but I assume it will be better than a standard non-sterile surgical mask. Adding a thin plexiglass-like shield over the mask (which has been well documented in the news recently) adds another layer of protection against aerosolized droplets.

Creating an air-tight seal between the mask and the face might be a challenge but using some type of tape/TPU is a quick and easy solution. I do worry about the airflow with a single 2.5 inch air filter, but I am sure the STL file can modified to add 2 filters to improve airflow.

Thanks again,

Jeff

Re: 3D Printed CoronaVirus Respirators

Posted: Wed Mar 25, 2020 10:47 pm
by Mach
haithco1 wrote:
Wed Mar 25, 2020 3:29 pm
Thanks for the great information. In addition to being a 3D printing enthusiast (I own a Makergear M3 ID), I'm a physician in practice at a 1000 bed hospital with multiple patients currently admitted for COVID-19. We have an acute shortage of masks (surgical masks, N95 masks, and related PPE equipment) so I plan on printing the model you linked to and see how it works. I just need to obtain the filter material and elastic bands to secure the masks to the head.

Thanks again for the info - I'll be curious to see how yours turns out after printing. I'm going to try PLA and maybe PETG (I'm awaiting a few PETG spools to be delivered soon).

Jeff
Hey Jeff, where in TX are you? I'm in Houston. I've got plenty of filament if you're in town.

Re: 3D Printed CoronaVirus Respirators

Posted: Thu Mar 26, 2020 4:27 am
by bobginpgh
I'm working with 3DPPGH, Pittsburgh's 3D printing user group on (mostly) face shields. My March 2013 M2 is still going strong printing a remix of the Prusa shield. Contact me if you want to help out with printing, or you can help by donating to or sharing the GoFundMe we launched for materials at bit.ly/2vSF8os