Global Centre for Clean Air Research (GCARE), Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom.
Global Centre for Clean Air Research (GCARE), Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom.
J Hazard Mater. 2022 Jan 15;422:126783. doi: 10.1016/j.jhazmat.2021.126783. Epub 2021 Aug 8.
We designed a novel experimental set-up to pseudo-simultaneously measure size-segregated filtration efficiency (η), breathing resistance (η) and potential usage time (t) for 11 types of face protective equipment (FPE; four respirators; three medical; and four handmade) in the submicron range. As expected, the highest η was exhibited by respirators (97 ± 3%), followed by medical (81 ± 7%) and handmade (47 ± 13%). Similarly, the breathing resistance was highest for respirators, followed by medical and handmade FPE. Combined analysis of efficiency and breathing resistance highlighted trade-offs, i.e. respirators showing the best overall performance across these two indicators, followed by medical and handmade FPE. This hierarchy was also confirmed by quality factor, which is a performance indicator of filters. Detailed assessment of size-segregated aerosols, combined with the scanning electron microscope imaging, revealed material characteristics such as pore density, fiber thickness, filter material and number of layers influence their performance. η and η showed an inverse exponential decay with time. Using their cross-over point, in combination with acceptable breathability, allowed to estimate t as 3.2-9.5 h (respirators), 2.6-7.3 h (medical masks) and 4.0-8.8 h (handmade). While relatively longer t of handmade FPE indicate breathing comfort, they are far less efficient in filtering virus-laden submicron aerosols compared with respirators.
我们设计了一种新颖的实验装置，可以同时测量 11 种类型的面部防护设备（FPE；四种呼吸器；三种医用口罩和四种自制口罩）在亚微米范围内的分级过滤效率（η）、呼吸阻力（η）和潜在使用时间（t）。不出所料，呼吸器的η最高（97±3%），其次是医用口罩（81±7%）和自制口罩（47±13%）。同样，呼吸阻力以呼吸器最高，其次是医用口罩和自制口罩。效率和呼吸阻力的综合分析突显了权衡取舍，即呼吸器在这两个指标上表现最佳，其次是医用口罩和自制口罩。质量因子也证实了这一层次结构，质量因子是过滤器的性能指标。对分级气溶胶的详细评估，结合扫描电子显微镜成像，揭示了材料特性，如孔径密度、纤维厚度、过滤材料和层数，影响它们的性能。η和η随时间呈指数衰减。使用它们的交叉点，结合可接受的透气性，可以估计 t 为 3.2-9.5 小时（呼吸器）、2.6-7.3 小时（医用口罩）和 4.0-8.8 小时（自制口罩）。虽然自制 FPE 的相对较长的 t 表明呼吸舒适性，但与呼吸器相比，它们在过滤载有病毒的亚微米气溶胶方面效率要低得多。
