Since the first cases of Covid-19 appeared, the use of masks gained popularity all over the world. Not only by the taste of the people, but by orders of the governments of different countries, states and municipalities. A study proved that the use of masks can reduce the spread of the virus by up to 85%. In fact, masks are essential now, but the material makes all the difference.
They cannot prevent a person from catching the disease, but they can decrease the incidence of released water droplets that could contain the virus. Thus, the use of masks is a way to ensure the safety of others and ourselves.
The problem is that not all people know the correct way to use masks. Another issue is the material used to make them.
In this model, the researchers used a face mask made from a folded scarf. Photo: Florida Atlantic University, Verma ETC.
Without a mask, sneezing can overcome social withdrawal
In a recently published study, researchers used a hollow mannequin head to examine the effectiveness of different types of masks, which are used to cover the nose and mouth. Everything was set up so that the positions of the mouth and nose were similar to those of an adult.
The researchers placed the head at a height of 1.72 meters, to simulate an adult man of average height. In addition, they installed equipment to give pressure, reproducing sneezing.
To emit particles that could be captured in images, the team used a fog machine. Then, using a green laser, they created an expansion effect to identify where the "sneeze" could dissipate.
In the representation, the mannequin wears a non-sterile cone mask. Photo: Florida Atlantic University, Verma ETC.
Masks are essential now, but the material makes all the difference, study shows
Simple single-layer masks, some homemade cotton masks sewn with two pieces of fabric, and a non-sterile cone mask were tested.
The findings indicated that single-layer masks failed to perform well in stopping the smallest droplets, which could stay in the air for days. On the other hand, the most effective were the multi-layer home masks, as well as the non-sterile cone masks, which helped reduce the range of coughs and sneezes.
In this model, the mannequin wears a face mask with two layers, made of alcochoado cotton. Photo: Florida Atlantic University, Verma ETC.
The problem is that even in the best masks there was some leakage, still, the results were much better than in the mask of simple.
"In addition to providing an initial indication of the effectiveness of protective gear, the visual aids used in our study can help convey to the general public the rationale behind the guidelines and social distancing recommendations for wearing masks," said Siddhartha Verma, lead author of the study and assistant professor in the Department of Ocean and Mechanical Engineering atFlorida Atlantic University, in a statement.
The perfect material
A previous study published in ACS Nano had already shown that the material used in the production of handmade masks can make all the difference when it comes to containing the spread of the virus.
Initially the researchers tested masks composed of only one fabric sample, at this stage of testing, the high weave cotton fabric showed more effectiveness than the other fabrics. A single layer of a cotton fabric was able to contain up to 80% of the aerosol particles. But it was when the research team used the mixture of two fabrics, that they found the materialThe study showed that a mixture of two differently textured fabrics was more than 90% effective in containing the tiny aerosol particles.
During the study, combinations of cotton and silk, cotton and chiffon, cotton and flannel were tested.
The study was published in Physics of Fluids, check it out.