Aerosol filtration efficiency of household materials for homemade face masks: Influence of material properties, particle size, particle electrical charge, face velocity, and leaks
Aerosol filtration efficiency of household materials for homemade face masks: Influence of material properties, particle size, particle electrical charge, face velocity, and leaks
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DOI：
10.1080/02786826.2020.1817846
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发表时间：
2020-10-08
影响因子：
5.2
通讯作者：
Borrmann, Stephan
中科院分区：
文献类型：
--
作者：
Drewnick, Frank;Pikmann, Julia;Borrmann, Stephan
由于SARS-CoV-2病毒引起的COVID-19大流行，全球范围内广泛推广日常使用口罩。采用颗粒计数法测定了44种家用材料和几种医用口罩样品的颗粒大小相关过滤效率（FE;d（p）= 30 nm-10 μ m），并测定了压降（Δ p）。在样品材料之间和不同的颗粒尺寸之间发现了巨大的FE差异，从FE确定为福特（p）= 50-500 nm的颗粒到福特（p）= 30 nm的颗粒，特别是d（p）> 2.5 μ m的颗粒。在不同层数的测量表明，堆叠的纺织品可以被视为单独的过滤器和总FE和Δ p可以很容易地估计从各个层的功能，离开个别组合的繁琐的测量过时。对于许多材料，静电引力对直径达100 nm的颗粒的总FE有很大的贡献。测量确定的泄漏表明，1-2%的小部分泄漏面积已经可以严重恶化总FE。对于直径小于5 μ m的颗粒尤其如此，其中FE下降了50%甚至三分之二。我们的测量表明，通过堆叠足够数量的多层织物，可以在大颗粒尺寸范围内达到自制口罩的良好过滤效率，并且材料上的压降可以接受。然而，非常重要的是面罩的良好贴合性，以最大限度地减少泄漏流量和选择无害的面罩材料。
As a consequence of the COVID-19 pandemic caused by the SARS-CoV-2 virus, the widespread daily use of face masks is promoted worldwide. Particle-size dependent filtration efficiencies (FE;d(p) = 30 nm-10 mu m), applying a particle counting approach, and additionally pressure drops (Delta p) were determined for 44 samples of household materials and several medical masks. HugeFEdifferences were found between sample materials and for different particle sizes, spanning from FEwere determined ford(p)= 50-500 nm particles with significantly larger values ford(p) = 30 nm particles and especially for those withd(p)> 2.5 mu m. Measurements at different numbers of layers showed that stacks of textiles can be treated as separate filters and totalFEand Delta pcan readily be estimated from the features of the individual layers, leaving laborious measurements of individual combinations obsolete. For many materials, electrostatic attraction contributes strongly to overallFEfor particles up to 100 nm diameter. Measurements with defined leaks showed that already a small fractional leak area of 1-2% can strongly deteriorate totalFE. This is especially the case for particles smaller than 5 mu m diameter, whereFEdropped by 50% or even two thirds. Our measurements show that by stacking an adequate number of layers of many fabrics, decent filtration efficiencies can be reached for homemade face masks over large particle size ranges with acceptable pressure drop across the material. Very important, however, is good fit of the masks to minimize leak flows and selection of non-hazardous mask material.