Mask Math/Science Vignette: Mask Straps According to the guidance released by the WHO in December mask straps should be designed to withstand at least 10 lbs of force ( 44.5 Newtons). The materials that most straps are constructed from (e.g., cotton straps and silicone bands) easily meet these requirements. However, we’ve seen a number of […]
Key result: Quantitative testing shows that fabric masks constructed from spunbond nonwoven polypropylene (NWPP) and/or quilting cotton are breathable and can satisfy NIOSH criteria for breathability. Ready for more testing? Visit our MakerMask Lab Testing Campaign for details. Introduction: Breathable Masks Breathing isn’t optional, and as COVID continues and mask wearing becomes commonplace, we are […]
New test results show that upcycled spunbond nonwoven polypropylene (NWPP) mask materials can provide high-level (ASTM Level 2) fluid resistance. MakerMask has supported the use of spunbond NWPP in homemade mask designs because of its unique combination of breathability and hydrophobicity, or water resistance. Thanks to community contributions, we were able to put the fluid […]
The MakerMask project team has reviewed extensive literature on the science and manufacturing of NIOSH-approved respirators. We selected a multi-layered design that balanced increased filtration capabilities with permeability for breathing. The spunbond non-woven polypropylene (NWPP) outer layers use the same type of material used in medical-grade commercial masks, providing water-resistance for blocking droplet transmission and mechanical filtration from the structure of the fibers.