Scientists Tell What Fabrics Make The Best Homemade Masks

Scientists tell what fabrics make the best homemade masks

Only three layers of widely available fabrics retain at least 80% of drops. But the mask should fit snugly.

Photo: pixabay.com

The new coronavirus SARS-CoV-2 spreads mainly through droplets containing viruses that leave the respiratory tract of infected people. Wearing medical masks and respirators is one of the methods for preventing COVID-19.

The use of masks in public places is recommended by Rospotrebnadzor, the American Centers for Disease Control and Prevention (CDC) and many scientists. In conditions of scarcity of personal protective equipment, people often have to make masks on their own.

Scientists from the University of Chicago decided to figure out which widely available fabrics are best for making masks at home. Their research is published in ACS Nano, the journal of the American Chemical Society.

For research, scientists using a special camera created an aerosol, the particle diameter of which was from 10 nanometers to 6 micrometers. Then, using a ventilation unit, they blew this aerosol through different tissues. At the same time, a pressure was created, which corresponded to the pressure that occurs during breathing at rest. Scientists measured the number of particles and their sizes before and after passing through the tissues.

The combination of one layer of heavy cotton fabric with two layers of polyester-spandex chiffon captured 80% to 99% of aerosol particles. Scientists point out that this efficiency is close to the parameters of the materials from which the N95 respirators are made.

The masks had a similar effectiveness when replacing chiffon with natural silk or flannel. Quilted masks made of cotton fabric with cotton-polyester padding also showed good results.

Scientists write that cotton fabric can serve as a mechanical filter, while other fabrics act as an electrostatic barrier because they are able to hold static electricity.

In the experiment, even a slight violation of the mask fit led to a decrease in its efficiency by at least two times. Scientists emphasize that the mask should fit snugly on the face.