The Effectiveness of the Microbial Barrier Knitted Homemade Facemasks

ABSTRACT

Facemasks significantly reduce the dispersion of respiratory droplets that potentially carry the virus (COVID-19) when a person speaks, coughs or sneezes. Double jersey knitted fabrics made of cotton, Tencel and Viscose were made and designed. This paper aims to examine the effectiveness of single-layer and double-layer knitted masks by the microbial barrier permeability method. This method was used in a targeted manner because Bacillus Bacteria with a size of 0.5 µm in diameter is used to determine the permeability of the microbial barrier, which includes aerosol particles and approaches the size of the virus of 0.1 µm in diameter. The permeability results of the microbial barrier are presented concerning the number of layers and the raw material composition. Porosity (%) was also deter-mined based on microscopic images. The results of the microbial barrier effectiveness test showed an ineffective microbial barrier for 1 layer of the knitted fabric. However, stacking the mesh in 2 layers in-creased the microbial barrier efficiency by 70%. Functional design, combining layers of fabric and insertion of a previously developed antibacterial tencel nonwoven filter enables complete imper-meability to microorganisms, i.e. an effective microbial barrier.

摘要

当一个人说话、咳嗽或打喷嚏时, 口罩可显著减少可能携带病毒 (新冠病毒-19) 的呼吸道飞沫的扩散. 以棉、天丝、粘胶为主要原料, 研制了双层针织物. 本论文旨在通过微生物屏障渗透法检验单层和双层针织口罩的有效性. 该方法是以有针对性的方式使用的, 因为直径为0.5µm的芽孢杆菌用于确定微生物屏障的渗透性, 该屏障包括气溶胶颗粒, 并接近直径为0.1µm的病毒大小. 微生物屏障的渗透性结果与层数和原料组成有关。根据显微图像测定孔隙度 (%). 微生物屏障有效性测试结果表明, 1层针织物的微生物屏障无效. 然而, 将筛网堆叠成两层可将微生物屏障效率提高70%. 功能性设计, 结合多层织物, 并插入先前开发的抗菌非织造过滤器, 使微生物完全不受影响, 即有效的微生物屏障.

KEYWORDS:

• Facemask
• microbial barrier
• knitted fabric
• cellulose

关键词:

• 面膜
• 微生物屏障
• 纤维素
• 针织物

Highlights

• The effectiveness of knitted facemasks has not been sufficiently researched.

• When wearing a knitted facemask, it must be taken into account that the structure is stretched by about 10%, so the tests were performed in that condition.

• The efficiency of single-layer and double-layer knitted facemask was determined by examining the efficiency of the microbial barrier or dry permeability of microorganisms.

• This method was used in a targeted manner because Bacillus Bacteria with a size of 0.5 µm in diameter is used to determine the permeability of the microbial barrier, which includes aerosol particles and approaches the size of the virus of 0.1 µm in diameter.

• The results:

  • One layer of knitted fabric does not have an effective microbial barrier and does not provide protection against the penetration of microorganisms.

  • Stacking the knitted fabric in two layers increases the efficiency of the microbial barrier by 70%.

  • Complete impermeability to microorganisms is achieved by inserting a filter between two layers of fabric.

  • Given the results obtained and in order to achieve an effective microbial barrier, a functional knitted facemask design has been proposed.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was funded by the Croatian Science Foundation, Project [IP-2016-06-5278].