Though mask supplies have slowly increased in the US, many people are still turning to homemade masks for their daily needs. Multiple mask style patterns are freely available online, but questions remain over which materials are ideal for slowing and, ideally, blocking the small respiratory droplets that carry the virus. A new study out of Florida Atlantic University used a laser and sneezing apparatus to answer that question.
Perhaps the best-known face masks for blocking small droplets is the N95, which is reserved for use with medical personnel — plus it is uncomfortable to wear for any duration of time. More common are the paper-like blue medical face masks that are lightweight and rectangular in shape; these are inexpensive and increasingly available on the market, yet hard to find in some places. These masks tend to poorly fit many faces and can repeatedly slip upward toward the eyes.
Arguably most popular — in the US, at least — is a fitted cloth mask that features a sculpted region for the nose bridge and a tight, close fit on the face. You can identify these masks easily by looking for the seam down the middle. These masks offer the best fit for most people, but there have been heavy debates over which materials are best.
According to the new study, which was recently published in Physics of Fluids, homemade masks that are ‘well-fitted’ to the wearer’s face offer better droplet blocking than bandanas and the type of rectangular face masks that feature loose folds. These homemade masks were more effective when made from ‘multiple layers of quilting fabric,’ according to the researchers.
Also more effective than loose face masks and bandanas were cone-style face masks, which are rounded and look like the type of dust masks used during construction. These masks were, presumably, better than loose-fold masks because they have a tighter, more secure fit. With that said, even loose masks and bandanas were found to be more effective than not wearing a mask at all.
Using lasers, the study found that both of two latter masks — bandanas and loose folds — were able to reduce the travel of respiratory droplet jets produced by sneezing by distances of 1/8th to 1/2, depending on which was used (bandanas were more effective). When combined with social distancing, these masks help prevent the public from inhaling respiratory droplets that may contain the virus.