Dual filter respirator mask (COVID19, Coronavirus, etc.)

A 3D printable dual-filter respirator mask design that can be used in areas without access to traditional masks

COVID19

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Description

*** UPDATE ***
Based on further testing, I cannot recommend this design at this time. It does not provide a good enough seal on the face. See this video for new recommendations:

Disclaimer: This design has not been fully tested, and there are no guarantees that it will protect against coronavirus or anything else. It is hoped that this will provide substantially better protection than nothing at all, but USE AT YOUR OWN RISK.

UPDATE: We're not convinced we can get a good face seal with this mask design, so we're testing out this design now: https://www.billingsclinic.com/foundation/ One of our customers had good luck with this. See his results here: https://www.reddit.com/r/crowdsourcedmedical/comments/fouljj/3dcopperprintedtpufacemaskbillingsmask/

READ THIS FIRST: I am NOT presenting this as a ready-to-use solution. This is a community collaboration aimed at creating something that would be useful (by which I mean significantly better than nothing for medical workers who may not have any access to masks) and could be produced by people with 3D printers. The design being shared NEEDS MORE WORK, and it may not end up being effective at all. We just don't know yet. But I welcome to collaboration, and I do hope the medical professionals and/or those with facilities able to test these in a serious and quantifiable manner will do so and report back to us.

I'm personally not convinced the respirator mask is the best thing to focus on producing. It still needs work. There have been good ideas from the community, but the design in its current form is not a great solution. I trust in any medical professionals who get their hands on one of these to better determine if it would be helpful and to what extent.

I believe making face shields like the design from Prusa Research (https://www.prusaprinters.org/prints/25857-prusa-protective-face-shield-rc2) would be a better thing to focus on right now if you have a 3D printer. I ordered some clear 0.5mm PETG sheets and am waiting for them to arrive. As soon as they get here, I'll probably shift focus to producing those.

But at a time like this, I trust in the community to help take a mediocre idea and turn it into something fantastic, and I trust in the medical professionals to check whatever we come up with and determine which community-made design (if any) they see as effective.

This mask is based on the excellent design that was recently shared by Copper3D:
https://copper3d.com/hackthepandemic/

Printed using Copper3D PLActive antibacterial/antiviral PLA:
https://shop3duniverse.com/products/copper3d-plactive-an1-antibacterial-pla

Our testing showed that once you get a good seal around the mask, it becomes difficult to breathe with the single filter mechanism. So I modeled a new version that has dual filters. See our detailed write-up here:
https://3duniverse.org/2020/03/18/3d-printing-to-help-with-the-coronavirus-pandemic/

This mask uses two filters - one piece of nonwoven polypropylene and one of those circular cotton makeup removal pads.

Published data(1) has shown that the filtration materials used by this design (polypropylene, the same material used in surgical masks) achieves a filtration efficiency of 96.4% for microorganisms of 1 micron and 89.5% for microorganisms of 0.02 microns.

Video here:

Recommend printing with 0.2mm layer height and 25% infill, 1.5 extrusion multiplier.

If no antibacterial filament is available, consider using PETG. Standard PLA could also be used. In either case, the mask would need to be sanitized periodically in an alcohol bath.

This version has been scaled up to 115% for a better fit. You can scale it down a little if this doesn't fit on your 3D printer's print bed.

Source CAD files can be downloaded here in a variety of CAD formats. Feel free to help make these designs better. Remix and re-share! https://a360.co/2QKD6xS

References
1. Anna Davies, et al. Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic? Disaster Medicine and Public Health Preparedness, Available on CJO 2013 doi:10.1017/dmp.2013.43

Materials and methods

Copper3D PLActive (antibacterial / antiviral PLA). Unfortunately, this material is in short supply (and somewhat expensive). Normal PLA can probably be used if the mask is disinfected daily in an alcohol bath.

Printed at 0.2mm layer height with 20-30% infill. Thermoformed using a heat gun (near-boiling water can also be used).

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Comments

Mini 20140521logobonpetitEric Agro added this to the Way of life collection ago
9552b1243fd9ef18497f883d7a62e68e?default=blank&size=40Minihawk added this to the corona collection ago
9552b1243fd9ef18497f883d7a62e68e?default=blank&size=40Minihawk printed this ago
Carousel thumb maske001
Printed on:
Tronxy X5S
Result:
I only printed the mask and the plugs, did not use the TPU-parts and the honeycomb-thing. Printed out well.
Feedback:
I did use doublesided glue tape and a sponge as a seal. It seems to be close, when i put my hands to the both filters, its much harder to breathe. I use these cotton pads (two pieces per filter without honeycomb-part). I think it is saver to use this mask than to walk without it. I am trying the second mask out of TPU at the time, it is still printing.
Mini logogbClaymore added this to the covid collection ago
Bc7011359e6f54438045a9c76b49a94b?default=blank&size=40Pioneer Robotics commented ago

So update on this mask. I was able to do a FIT Test on this mask, and it passed with flying colors!! Usually with the 3M or Kimberly-Clark, I have to try 3 or 4 times to get a good enough seal to pass. This passed on the first try. I will be presenting the prototype and demo to our Incident Command Board tomorrow morning and will be doing a more extensive testing tomorrow. The biggest part was, the seal worked perfectly which I feel is due to it being molded to my face.

Since I am part of the purchasing board for my department I contacted the lead cardio'vascular purchasing agent within Trinity Health which kept me REALLY busy all afternoon today. I sent the stl file along with pictures of our prototype and our engineering notebook over to the Trinity Health 3D Department and they are going to duplicate the mask to send to the Emergency PPE Approval Department at the FDA. AirWolf3D is also sending me a prototype of this mask printed in polycarb, which I think will be a better, more sturdy choice for long term use. Only question will be how easy will it be to mold to ones face.

I will keep everyone posted as to what is happening as we work through this. Jeremy, thank you for all of your diligence of keeping this item updated and quickly implementing improvements.

3255c7f56e350e284d86ed7f2c2199bd?default=blank&size=40kristian ekendahl commented ago

Nice work. I have made modified version that fits my cheap printer, and is printed as one piece (I used regular PLA). I modified the caps a bit, since they were rather hard to turn, and one got mirrored so it turns the other way. To shape it, I put it in warm water (73 C) and to insulate it I used sealing strips for windows. I am novice at this, so take it for what it is. Here is a link: https://www.tinkercad.com/things/4kjG2iijAVw

3772de271d01e35d5868c1c5d648fb7c?default=blank&size=40Edgar Rot commented ago

Hi Jeremy,

great job. But I have only a doubt about the space between the print layers. As far as I found on the web it should be about 1 micron, whereas the coronavirus dimension is around 0.1 micron.

What do you think? It can be a problem?

Mini screen shot 2013 07 15 at 6.49.36 pmErik de Bruijn commented ago

To Airwolf3D, Eva and Erick: We really appreciate the efforts you're putting into COVID19 mitigation.

If possible, can you share what you learned from the meeting with ICU doctors? I will disseminate it in open source communities as soon as possible and while crediting Airwolf3D.I will be doing the same from what I learn from my communications with hospitals. My info can be found on Slack:https://osventilator.slack.com/https://otherosvprojects.slack.com/

The above projects (especially osventilator) has a dozens of medical professionals as part of a 1000+ strong community. It could be useful to join the second one as well, as it's very broad and deals with all kinds of supplies and tools for mitigation.

I like the idea of using polycarbonate for autoclaves. Will also look into this.

A22d34257cd1a9d0bb03130bbebe8fe2?default=blank&size=40airwolf3d commented ago

Hi Sheila,

Can you please keep us in the loop?  We have an army of professional-grade 3d printers ready to mass-produce these masks at a moment's notice.  Our 1000's of customers also have 3d printers and are standing by to help.

Alternatively, we are prototyping alternatives that you may want to test.  For example, we have the capability to print in polycarbonate which can be sterilized with heat, autoclave, etc.

We are meeting with the doctors from UCI tomorrow to provide prototypes for evaluation.

Thank you for doing all this and take care!

https://airwolf3d.com/2020/03/17/airwolf3d-offering-emergency-additive-manufacturing-services/

"Sheltering at Work"

Eva & Erick Wolf and Family

covidmedicalemergency@airwolf3d.com

Eeadf8886dcc564560106454135617d7?default=blank&size=40Sheila Wintergerst commented ago

Hi Jeremy,

We are currently printing this N95 along with the updates and fitting to my face. I am a Healthcare provider and have access to equipment to check these, which I will be doing tomorrow. The heas of Infectious Disease is aware of me trying to get this done and would like to get these in mass production pending on the results. We have the connections within the State of Michigan to possible get mass production done. I would like to keep you involved with this process and would love to discuss more in depth of any updates. I will let you know what we find out with the Fit Test tomorrow and what our Infectious Disease and Incident Command Center comes back with.

Thank You for all of your thought and help with this! N95 are the number one piece of equipment that is in highest need to prevent the spread of COVID 19 amongst our Healthcare providers.

Eeadf8886dcc564560106454135617d7?default=blank&size=40Sheila Wintergerst commented ago

Hi Jeremy,

We are currently printing this N95 along with the updates and fitting to my face. I am a Healthcare provider and have access to equipment to check these, which I will be doing tomorrow. The heas of Infectious Disease is aware of me trying to get this done and would like to get these in mass production pending on the results. We have the connections within the State of Michigan to possible get mass production done. I would like to keep you involved with this process and would love to discuss more in depth of any updates. I will let you know what we find out with the Fit Test tomorrow and what our Infectious Disease and Incident Command Center comes back with.

Thank You for all of your thought and help with this! N95 are the number one piece of equipment that is in highest need to prevent the spread of COVID 19 amongst our Healthcare providers.

Eeadf8886dcc564560106454135617d7?default=blank&size=40Sheila Wintergerst commented ago

Hi Jeremy,

We are currently printing this N95 along with the updates and fitting to my face. I am a Healthcare provider and have access to equipment to check these, which I will be doing tomorrow. The heas of Infectious Disease is aware of me trying to get this done and would like to get these in mass production pending on the results. We have the connections within the State of Michigan to possible get mass production done. I would like to keep you involved with this process and would love to discuss more in depth of any updates. I will let you know what we find out with the Fit Test tomorrow and what our Infectious Disease and Incident Command Center comes back with.

Thank You for all of your thought and help with this! N95 are the number one piece of equipment that is in highest need to prevent the spread of COVID 19 amongst our Healthcare providers.

Mini screen shot 2013 07 15 at 6.49.36 pmErik de Bruijn commented ago

Because of COVID, European Norms regarding face masks are now published free of charge. This link pertains to: Respiratory protective devices - Filtering half masks to protect against particles https://www.hzn.hr/UserDocsImages/pdf/HRN%20EN%20149_2010.pdf

929f1ff540aa35481f7f5a1d56eb2717?default=blank&size=40Greg Griffes commented ago

@Erik de Bruijn @Threaded Filters: Thank you for the information, I will try it! I rarely change the filter on my CPAP, I shouldn’t let it go so long, which is why I have extra filters, so, I’m not concerned about not being able to get them. But you have a good point, we would need to make sure we don’t create shortages. I’ll check the link you sent.

Mini screen shot 2013 07 15 at 6.49.36 pmErik de Bruijn commented ago

For deciding which material to use as an effective filter, have a look here:

https://smartairfilters.com/en/blog/best-materials-make-diy-face-mask-virus/

Mini screen shot 2013 07 15 at 6.49.36 pmErik de Bruijn commented ago

@Greg Griffes: @Threaded Filters: It could help if you print one object at a time (fewer jumps, fewer hairs). Also, if you can increase travel speed that helps. If it's already at the max, you can lower the print speed and keep travel speed high, this way there is less pressure on the filament and so, less oozing. Also, the retraction settings are more important with TPU / Copper3D since it's more flexible. They need to be higher than PLA, for instance.

Re your other point: a CPAP mask could work if you add a 3D printed adapter to add a filter to it. CPAP supplies might not be depleted yet, however these devices could also become important to people who are already extra vulnerable because they have respiratory issues. We probably don't want to create a shortage there to alleviate another shortage... maybe this is unlikely to happen, but I can't say for sure.

929f1ff540aa35481f7f5a1d56eb2717?default=blank&size=40Greg Griffes commented ago

General comment: I think the point of wearing a mask during this crisis is to protect other people from your cough or sneeze and it won't protect you from catching the virus (except that it makes it harder to touch your nose and mouth.) If that is true, then it is more important that the exhale is contained. I'm not a medical professional and I could be wrong, but if I'm right, the exact fitting, filtering, and sealing may not be critical to achieve. I was thinking about using a CPAP filter and not spending a lot of time on sealing the gaps which will make the masks easier to produce and easier to breathe. Seems to me that a sneeze with the mask on would be pretty well contained and any droplets that escape will stay close to the face.

929f1ff540aa35481f7f5a1d56eb2717?default=blank&size=40Greg Griffes commented ago

I've been printing the Copper3D but I like the two filter design and will try that next. I'm having trouble printing the Threaded Filter, the air gaps are hard for my printer to traverse the distance and I end up with drooping fibers and rework. Any suggestions for slicer settings or other ideas? I'm using regular PLA and a Qidi X-Pro printer.

929f1ff540aa35481f7f5a1d56eb2717?default=blank&size=40Greg Griffes added this to the N95 Mask collection ago
E6d370e2534524cea81557fde427e3f6?default=blank&size=40uranushertz added this to the CleanHands collection ago
Mini screen shot 2013 07 15 at 6.49.36 pmErik de Bruijn commented ago

Awesome to see this design here and great to "see you" again :)

Mini screen shot 2013 07 15 at 6.49.36 pmErik de Bruijn added this to the COVID19 collection ago
E2e4bf905bfa8f4c7b69f9212670db58?default=blank&size=40Jeremy Simon published this design ago