Foggy":3ayl1e1s said:
SNIP...consider the mask fabric porosity is much larger than the virus.
Also know the virus is contained in MUCH LARGER PARTICLES less likely to
penetrate the fabric... SNIP
The objective of the DIY absorbent mask is to trap liquid particles containing
viruses coming into and out of the mask, not solo floating virus particles.

sad PLACEBO) Any mask worn must snuggly fit over the nose and mouth.
And don’t forget eye protection for COVID-19.
Small measurements:
1 nanometer = 1 nm = 1/1,000,000,000 meter = 1/1,000 micron
1 micron = 1/1,000,000 meter = 1/1,000 millimeter = about 1/25,000 inch
Small human things:
Red blood cell: 7 - 10 microns
Hair diameter: 10 -100 microns - also size of “fine fog”
Cough/sneeze liquid/mucous particle size:
8 - 14 microns (small)
57 - 68 microns (medium)
96 - 114 microns (large)
Size of general virus class: 10 - 400 nm = 0.01 - 0.40 microns
Size of COVID-19: 120 nm = 0.120 micron
Pore size cotton fabric: 20 - 100 microns (2 layers overlapped decrease pore size)
Pore size coffee filter: 5 - 100 microns (added to above decrease pore size further)
So, 2 layers of t-shirt fabric + 1/2 of a #2 coffee filter may have overlapping
'pores' that can trap medium-large particles containing the much smaller virus.
In fact, studies support this.
Refs:
https://smartairfilters.com/en/blog/diy ... ronavirus/
https://www.bing.com/images/search?q=po ... BasicHover
“Tests have found that DIY masks can filter a percentage of virus-sized
particles. While they’re not as effective as surgical or N95 masks at filtering
viruses, they still can provide some benefit. They also reduce hand-to-face
contact.”
Aye.