In a new study, researchers used principal component analysis along with fluid dynamics simulation models to show the crucial importance of proper fit for all types of masks and how face shape influences the most ideal fit. They modeled a moderate cough jet from a mouth of an adult male wearing a cloth mask over the nose and mouth with elastic bands wrapped around the ears and calculated the maximum volume flow rates through the front of mask and peripheral gaps at different material porosity levels.
Click here for original story, Face shape influences mask fit, suggests problems with double masking against COVID-19
Source: ScienceDaily