Study of the aerosol particle filtration efficiency of fabrics used to manufacture non-medical face masks in Lithuania
The global spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) proved to be a challenge for public health. The high demand of medical masks worldwide during the pandemic has led to a critical situation for decision-makers regarding high-quality mask supply. For this period, the World Health Organization has suggested the use of non-medical face masks (also known as ‘community’ masks) in public places to reduce the airborne spread of SARS-CoV-2. In this study, the filtration efficiency of various fabrics widely used in community masks was determined based on two main mask filtering properties: filtration efficiency (FE) and pressure drop (ΔP) according to the recommendations of the CEN Workshop Agreement (CWA) 17553:2020. The combination of FE and ΔP parameters must be considered in order to select suitable materials for public masks. The filtration efficiencies for various fabrics ranged from 6 to 100%. It was found that the composite materials have the highest FE equivalent to the requirements of a medical mask (FE > 95%), that is confirmed by high-quality parameters 16–30 kPa–1. The study found that fabrics of natural fibres (100% cotton) have a higher FE with Ag coating (18–40% before and 29–40% after coating) in the 0.54–1.50 μm particle size range.