A highly efficient cloth facemask design
A highly efficient cloth facemask design
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DOI：
10.1080/02786826.2021.1962795
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发表时间：
2021-07-31
影响因子：
5.2
通讯作者：
Roman, Sanziana A.
中科院分区：
文献类型：
--
作者：
Cappa, Christopher D.;Ristenpart, William D.;Roman, Sanziana A.
戴口罩和面罩有助于减少呼吸道疾病的传播。许多关于口罩过滤效率的先前研究集中在织物类型上，较少考虑口罩设计和形状。在这里，我们提出的证据表明，增加口罩分离距离会增加口罩织物过滤效率对呼出气溶胶通过发声，我们归因于呼气射流速度的下降和呼吸面罩接触面积的扩大。我们进一步评估了一种新的可重复使用的布面罩设计的性能，这种设计最初是为专业歌手设计的，但不是专为专业歌手设计的，并且具有较大的口罩间隔距离。通过适当的佩戴，这些口罩对唱歌和说话时呼出的直径>0.5微米的气溶胶以及吸入的环境气溶胶的总体过滤效率均达到>93%，优于外科口罩和接近N95的净化器。面罩死腔和周围环境之间的空气交换限制了吸入空气中CO2积聚的程度，并将O-2水平保持在接近环境的水平。口罩设计还提供了较少的抑制嘴和下巴的运动和较低的相对湿度，这表明它可以为公众提供一个更可口，高效的替代医疗级口罩。版权所有（c）2021美国气溶胶研究协会
Wearing masks and face coverings helps reduce transmission of respiratory diseases. Much prior research on mask filtration efficiency has focused on fabric type, with less consideration given to mask design and shape. Here, we present evidence that increasing the mouth-mask separation distance engenders an increase in the mask-fabric filtration efficiency toward expiratory aerosols emitted via vocalization, which we attribute to a decrease in the expiratory jet velocity and expansion of the breath-mask contact area. We further assess the performance of a new reusable cloth facemask design, originally made for, but not exclusive to, professional singers and having a large mouth-mask separation distance. With proper fitting, these masks achieve overall filtering efficiencies of >93% for both exhaled expiratory aerosols >0.5 microns in diameter from singing and speaking and for inhaled ambient aerosols, better than surgical masks and approaching N95 respirators. Air exchange between the mask deadspace and the ambient environment limits the extent of CO2 buildup and in inhaled air and maintains O-2 levels near ambient. The mask design also provides for less inhibited mouth and jaw movement and lower relative humidity, suggesting it may provide a more palatable, high-efficiency alternative to medical-grade masks for the public. Copyright (c) 2021 American Association for Aerosol Research