Coronavirus Disease 2019 (COVID-19) may spread through respiratory droplets released by infected individuals during coughing, sneezing, or speaking. Given the limited supply of professional respirators and face masks, the U.S. Centers for Disease Control and Prevention (CDC) has recommended home-made cloth face coverings for use by the general public. While there have been several studies on aerosol filtration performance of household fabrics, their effectiveness at blocking larger droplets has not been investigated. Here, we ascertained the performance of 11 common household fabrics at blocking large, high-velocity droplets, using a commercial medical mask as a benchmark. We also assessed the breathability (air permeability), texture, fiber composition, and water absorption properties of the fabrics. We found that most fabrics have substantial blocking efficiency (median values >70%). In particular, two layers of highly permeable fabric, such as T-shirt cloth, blocks droplets with an efficiency (>94%) similar to that of medical masks, while being approximately twice as breathable. The first layer allows about 17% of the droplet volume to transmit, but it significantly reduces their velocity. This allows the second layer to trap the transmitted droplets resulting in high blocking efficacy. Overall, our study suggests that cloth face coverings, especially with multiple layers, may help reduce droplet transmission of respiratory infections. Furthermore, face coverings made from materials such as cotton fabrics allow washing and reusing, and can help reduce the adverse environmental effects of widespread use of commercial disposable and non-biodegradable facemasks.

2019年冠状病毒病（COVID-19）可能会在咳嗽，打喷嚏或说话期间通过感染个体释放的呼吸道飞沫传播。鉴于专业呼吸器和面罩的供应有限，美国疾病控制与预防中心（CDC）已推荐自制的布面罩供广大公众使用。尽管已经对家用织物的气雾过滤性能进行了几项研究，但尚未研究它们在阻止较大液滴上的有效性。在这里，我们以商用医用口罩为基准，确定了11种常见家用织物在阻挡大的高速液滴上的性能。我们还评估了织物的透气性（透气性），质地，纤维成分和吸水性能。我们发现大多数织物具有相当大的粘连效率（中值> 70％）。尤其是，两层高渗透性织物（例如T恤衫布）以类似于医用口罩的效率（> 94％）阻挡液滴，同时透气性约为后者的两倍。第一层允许约17％的液滴通过，但会大大降低其速度。这允许第二层捕获透射的液滴，从而导致高阻断效率。总体而言，我们的研究表明，布面覆盖物（尤其是多层覆盖物）可能有助于减少呼吸道感染的飞沫传播。此外，用棉布等材料制成的面罩可以清洗和重复使用，