Wearing a mask is one of the most important strategies to save oneself from COVID 19. According to the Center for Disease Control and Prevention, the surgical mask and N95 mask should be left for medical professionals who are working on the front line. So, what about the general population? As per government, we can simply make our own cloth mask at home.
The first question that arises when you think of making a mask at home is which material to use?
Researchers from the Argonne National Laboratory and the University of Chicago in the United States have tested a variety of common materials under various laboratory conditions to investigate their mechanical and electrostatic filtration properties.
The best material
The research found that multiple layers and mixing up fabrics worked the best to filter particles. But again, if you mask is ill fitting, it fails the whole purpose.
The research was conducted on various common fabrics including cotton, silk, chiffon, flannel, various synthetics and their combinations.
“Overall, we find that combinations of various commonly available fabrics used in cloth masks can potentially provide significant protection against the transmission of aerosol particles,” said the researchers.
“Filtration efficiencies of the hybrids (such as cotton–silk, cotton–chiffon, cotton–flannel) was >80 per cent (for particles <300 nanometres) and >90 per cent (for particles >300 nanometres),” the researchers wrote.
The researchers speculate that the enhanced performance of the hybrids is likely due to the combined effect of mechanical and electrostatic-based filtration.
Mechanical filtration
The team found that for fabrics such as cotton, high thread count works the best. The smaller the holes, the fewer large particles can escape. This is mechanical filtration, where the fabric is physically catching the particle.
Electrostatic filtration
For example, static fabrics like polyester, the electrostatic filter keep the aerosols inside the static environment.
Verdict
A combination of different fabrics (layering multiple materials) is the best way to filter the vast majority of particles.
Remember
All of this doesn’t work if you do not wear your mask correctly. The gaps caused by improper fitting can result in 60 per cent decrease in filtration efficiency. So, whatever mask you purchase or make, make sure you wear it correctly.