16 layers of spunbond NWPP in a mask
Three masks pictured together. Left to right
- 8 layers of 38 gsm NWPP - 180 TPI cotton outer.
- 16 layers of 38 gsm NWPP (no outer layer)
- 6 layers if cheap polyester satin (no outer layer) - straps stolen for mask #2
Mask #2 is the new one - 6 mins to make. Or would have been
if the needle didn't break in a 5mm 48-layer intersection. The needle tip is still in the mask :(
Mask #2 is 608 gsm of spunbond NWPP (or 672 gsm
if we go by my weighing of the fabric)
Mask #1 is what I wore today for 8 hours in an
office setting. In this pic, washed but not dried.
Masks #1 and #2 are easier to breath through than
mask #3 (which is why I gave up on satin). Yes, I have
checked mask #2 for breathability.
Wearing the 16 layer NWPP mask
It is fine. Comfortable. Breathable - I can fill my
lungs from zero in about a second and empty just as fast.
The fabric, as before, is fine against my face. It doesn't smell.
Filtration effectiveness for 608 0r 672 gsm is total guesswork at this stage :( Tests needed!!
Layering calculations: https://math.stackexchange.com/q/3698080/794361
If you thought that layers were purely additive and no reduction factor was needed ....
(better results- less layers for the same filtration)
Bonus pic: Mask #1 drying on the radiator. Well, the
radiator is not on presently, but it will be later: