N95 Mask Idea

General Discussion
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First: FormLabs, you guys should really add a COVID-19 category for you forum so that people can properly post ideas / projects / and progress.

N95 Mask Idea
I have done some reading, on form labs, CDC, and FDA white papers regarding additive manufacturing of medical devices. Focusing on the N95 masks. From what I have read, formlabs machines are not capable of printing filters. The layer resolution cannot get small enough to ensure that they function properly. There is also an issue in general with 3D printing masks out of hard plastic, because it is very hard to get a good seal. By no means am I a doctor, or educated in any form of medical type engineering. So please take the following with that in mind.

The filter problem
As stated above FormLabs machines cannot print fine enough to create filters. But they should be able to make everything else for these masks. If we can take current N95 rated masks and cut them up to be used as filters in the 3d printed masks. Takeing one mask (like the one shown here) N95%20Mask%20No%20Filter and possibly turning it into 5-6 masks. By cutting the masks into disks to be placed into a re-usable/sanitize-able 3D printed filter.

Replaceable%20Disk%20Filter
Replaceable%20Disk%20Filter1425×791 69.4 KB
. I am not sure if the N-95 disk will be a consumable or if the disks can be sanitized, but I think it would be worth looking into.

The fit and seal problem
FormLabs has a wide variety of engineering materials. Some are not rigid plastic. Printing the bulk of the face covering in flexible or elastic, a good seal should be able to be made. The mask should be designed so that the fastening mechanism to the wearers head is easily replaceable with varying sizes of strings. Maybe use a separate printed part for the back of the head that is adjustable like a hard hat? This still leaves the issue of extra particles making it through the mask that get through the layer resolution on the printer. Using a dip coating (of some kind) that would seal the mask portion entirely much like how a UV sealant is applied to prints currently. May make them usable.

Combining, the two concepts a reusable system may be 3D printable. These are just some thoughts I had on the problem. Please let me know what you think.

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If only it were that easy … you could also cut a vacuum cleaner bag into 100 parts and vacuum clean 100 times longer.

The filter performance is always determined by the surface. On the one hand, the N95 mask has to bind particles from the outside and then also have to cope with the high humidity from the breathing air. If the filter gets too wet, it will be tight and no more oxygen will come through. Then you wish you had a scarf in front of your nose and mouth.

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Below is an interesting article that includes a 3d printable design. Thoughts?

Maker Mask

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Maker Mask facts:

  1. Hepa filter used (class unknown): Hepa filters can trap particles down to 0.3 micrometers. However, the diameter of Sars-CoV-2 is only around 0.1 micrometer. Protection against viruses is therefore only limited for the wearer. However, the protection should not be comparable to an FFP mask.

  2. The mask has an outlet valve: This means that the surroundings are NOT protected from possible infection

  3. The base body is rigid and inflexible: unfiltered air can penetrate at leaks.

  4. The mask has not been approved by the United States Food and Drug Administration (FDA) or other regulatory agency.

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Thank you for the suggestion. A new forum subsection has been created.

http://forum.formlabs.com/c/covid-19-related-topics
3 Likes
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The only reason any of these masks work against viruses, is that the viruses are traveling on somehting else. Water vapor, spittle, dust, dirt… anyhting.

Because of this… and the fact that eveything mentioned above is larger than 0.3 microns… it works.

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Yes, I agree. N95 Filter Capacity (removes 95% of of all particles that are 0.3 microns in diameter or larger)

But this also means that up to 5 percent of the particles pass through the filter.
It is not a 100%, you should be aware of that.

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Ive also wanted to print some face masks. Its a good thing I found this thread. Information here has been really useful.

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Well your research sounds pretty interesting. Have you thought on doing any experiments? Also, if you can mention some other masks that can possibly get 3d printing.

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It seems to me that a 3D printer is not capable of creating a full-fledged air filtration in a mask. Of course, for the sake of entertainment, you can also print a mask, but it is better to wear masks made of special fabric.