一种测试口罩材料在打喷嚏样压力下过滤效率的新方法。
A New Method for Testing Filtration Efficiency of Mask Materials Under Sneeze-like Pressure.
机构信息
Department of Pharmacology, School of Life Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan
Meikai University Research Institute of Odontology (M-RIO), Saitama, Japan.
出版信息
In Vivo. 2020 Jun;34(3 Suppl):1637-1644. doi: 10.21873/invivo.11955.
BACKGROUND
Sneezes produce many pathogen-containing micro-droplets with high velocities of 4.5-50.0 m/s. Face masks are believed to protect people from infection by blocking those droplets. However, current filtration efficiency tests can't evaluate masks under sneeze-like pressure. The goal of this study was to establish a method to evaluate the filtration efficiency of mask materials under extreme conditions.
MATERIALS AND METHODS
Efficiency of surgical masks, gauze masks, gauze, cotton, silk, linen and tissue paper on blocking micro-droplet sized starch particles (average 8.2 μm) and latex microspheres (0.75 μm) with a velocity of 44.4 m/s created by centrifugation was qualitatively analyzed by using imaging-based analysis.
RESULTS
The 4 layers of silk could block 93.8% of microspheres and 88.9% of starch particles, followed by the gauze mask (78.5% of microspheres and 90.4% of starch particles) and the 2 layers of cotton (74.6% of microspheres and 87.5-89.0% of particles). Other materials also blocked 53.2-66.5% of microspheres and 76.4%-87.9% of particles except the 8 layers of gauze which only blocked 36.7% of particles. The filtration efficiency was improved by the increased layers of materials.
CONCLUSION
Centrifugation-based filtration efficiency test not only compensates shortcomings of current tests for masks, but also offers a simple way to explore new mask materials during pandemics. Common mask materials can potentially provide protection against respiratory droplet transmission.
背景
打喷嚏会产生许多含有病原体的高速微液滴，速度可达 4.5-50.0 m/s。人们认为口罩可以通过阻挡这些飞沫来保护人们免受感染。然而，目前的过滤效率测试无法评估口罩在类似于打喷嚏的压力下的性能。本研究的目的是建立一种方法来评估口罩材料在极端条件下的过滤效率。
材料和方法
通过基于成像的分析，定性分析了外科口罩、纱布口罩、纱布、棉花、丝绸、亚麻和纸巾在阻挡离心产生的速度为 44.4 m/s 的微滴大小的淀粉颗粒（平均 8.2 μm）和乳胶微球（0.75 μm）的效率。
结果
4 层丝绸可以阻挡 93.8%的微球和 88.9%的淀粉颗粒，其次是纱布口罩（78.5%的微球和 90.4%的淀粉颗粒）和 2 层棉花（74.6%的微球和 87.5-89.0%的淀粉颗粒）。其他材料也可以阻挡 53.2-66.5%的微球和 76.4%-87.9%的淀粉颗粒，除了 8 层纱布，它只阻挡了 36.7%的淀粉颗粒。过滤效率随着材料层数的增加而提高。
结论
基于离心的过滤效率测试不仅弥补了目前口罩测试的不足，而且为大流行期间探索新的口罩材料提供了一种简单的方法。常见的口罩材料可能能够提供对呼吸道飞沫传播的保护。
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