This reusable face mask uses a pleated HEPA filter to let ...
Jun 30, 2020·In the case of cloth masks, the entire mask acts as a fabric filter, and with something that’s non-porous, like plastic or silicone, you’ve got air valves and smaller filters that can be detached, cleaned, or replaced. That’s the basic schematic of a mask, and a lot of designers and companies are looking to perfect it.