Nanofiber filters that fit perfectly inside the filter pocket of Becky’s Handmade face masks
With Covid-19 rates skyrocketing, the news of more contagious Coronavirus variants gaining prominence, and recommendations for double-masking circling everywhere, I started feeling like even three layers of cotton fabric might not be enough protection. After a lot of research and trying out different DIY and commercially-available filter materials – with varying degrees of filtering capabilities and breathability – I discovered Filti nanofiber fabric.
Filti claims that their fabric is (up to) 95% effective in filtering out sub-micron (0.3 micron) particles. You can check out the company’s material data sheet for more details. Independent tests by TSI, Inc. found filtering results for Filti fabric more in the 84-87% range. (Take a look at the “1 layer Filti + 2 layers of cotton” result, which comes in at 86.44% filtering efficiency.) Obviously, that isn’t as good as an N95 or KN95 mask*, but it’s much better than other DIY filter materials I’ve tried, such as non-woven interfacing, and is more breathable. For a person who is not at particularly high risk, but who wants to protect themself and others from Covid spread, it seems that three layers of high-quality cotton plus a fourth filter layer, combined with the excellent fit of Becky’s Handmade masks, offers a great combination of comfort, convenience, breathability, and – most importantly – protection.
Important notes about Filti mask filters:
- FILTI FABRIC IS NOT WASHABLE!!
- Washing the Filti nanofabric reduces its filtering capacity to only around 45% or lower.
- Remember to remove the filter before washing your mask!
- Filti fabric can be sanitized in the oven. Check out this video with instructions from the material manufacturer.
- Position the filter as close to the top seam as possible for the best protection.
Because the Filti fabric cannot be washed, all filters are placed in “isolation” for at least one week before delivery or shipping as an extra precaution.
*Filti mask filters, as well as Becky’s Handmade cotton masks, are not medical grade and no medical or scientific claims are made. Use the information provided and make up your own mind about whether they are right for you.
DISCLAIMER FROM FILTI: Filti makes no warranties, either expressed or implied that this material or masks made from it, prevent infection or the transmission of viruses or diseases. Do not use this material in any setting or where significant exposure to liquid, bodily or other hazardous fluids, may be expected. Do not use this in settings where the infection risk level through inhalation exposure is high. Do not use this material in the presence of an open flame, heat source or flammable gases or liquids. All data contained above is nominal and provided for informational purpose only. This data is not to be construed as manufacturing specifications and is subject to change. Filti does not guarantee the performance of this material in a face mask or the performance or masks made from it. Filti Face Mask Material is not a substitute for medical treatment or medical devices.