Recently, a diary was posted in which a call for people who sew was put out.
Do you have a sewing machine?
Sew some face masks!
More sewing!
In the original diary, I put out the idea of “pocket masks” and linked to a video with a pattern:
Comment thread here
Several amazing people responded, and I promised to test out the idea of cutting HEPA-grade furnace filters.
So here’s the result.
First, get a NEW filter (they come in packages of 2, 5, 10, and more).
Strip off the cardboard frame: careful, there’s wires in the HEPA material, and the material is glued to the frame. A good set of shears works really well.
After you strip the frame, flatten the filter material.
Mark with a sharpie or whatever, and cut the insert to shape… this depends on the kind of mask you’ve made and the shape of the pocket you created.
One side of the filter is “fabric only” it’s about 1/8 inch thick, and fuzzy. It is comprised of many many fine fibers and is intended to have “loft” to maximize the flow path of the air going through. More chances to catch particles.
The other side of the filter has a wire mesh. This provides structural support to keep the fuzzy material in shape, and I am pretty sure it also acts as an electrostatic “magnet” for airborne particles and particularly water droplets…
The HEPA filter is rated to trap particles down to 0.3 microns, and is especially effective at catching charged particles like dust, water droplets, and … mucous. Water is a dipolar molecule and will be “caught” electrostatically and mechanically. Most of what people are spraying out is NOT “just virus” it is virus particles wrapped in mucous. Trap that mucous before it touches you or gets into your airways.
en.wikipedia.org/…
These filter frames can be purchased at almost any hardware store or “big box” like Lowes, Home Depot, Walmart, and they’re cheap.
Putting these kinds of inserts into a home-made fabric mask will never reach the level of a true N-95, R-95 or P-95 NIOSH respirator antiviral mask
en.wikipedia.org/…
But I think with two layers of fabric (the pocket) and this kind of insert… you could get damned close.
Simple, easy, cheap!
EDIT: Colorado Blue, in comments, has suggested (wisely!!) that pretty much any HEPA filter material will work: Air purifiers, Vacuum Cleaners, Humidifiers… whatever! All that is needed is enough material to make the insert.