3M Respirator Mask Exhaust Clip

thingiverse

I found a wonderful design which provides filter cartridges for a 3M respirator here, at this link: https://www.thingiverse.com/thing:4234928 I took apart a 3M Filtrete furnace filter and used it as the filtering material. Their furnace filters use the same micron-sized filtration material as 3M uses in their N95 masks. Just make sure you get the Filtrete Allergen line with a model number of 1500 or above. The attached photos show the furnace filter after I took it apart, and what the cartridges referenced in the link above look like. I then show what my part looks like, and how I cut the filter material for the exhaust port. My part clips to the outside, and includes a small circle which fits around the top outside of the exhaust port which is also circular. This circular ridge in my part is what holds the filter in place and provides a seal of the filter so that all air exits through the filter, and not around it. Having this exhaust filter not provides protection to others from YOUR germs, but it also provides a "fail-safe" in case the exhaust valve on your mask begins to degrade and not seal perfectly. This is how these masks eventually fail. With this filter on the exhaust side, you will still be protected should that exhaust valve fail. You cannot print this in PLA because it is too rigid and brittle. PETG works great and is what I used. I have provided the Fusion 360 f3D file for those who want to adjust the design.