Surgical masks are typically used in large cities in East and Southeast Asia to limit the inhalation of air pollutants or contamination by viruses such as the flu or COVID-19. Thus, they are widely used in China, Hong Kong, Vietnam, and even in places such as Toronto during the SARS outbreak in 2002–2003, in Mexico during the influenza A (H1N1) epidemic in 2009, and many countries during the 2019–2020 coronavirus pandemic. In the event of a shortage, surgical masks are recommended for nursing staff and people exhibiting symptoms (cough and fever).
Facial surgical masks are normally manufactured with non-woven, melt-blown fibers from polymer materials such as polypropylene, which allows airflow through the mask while filtering airborne microorganisms such as bacteria, bioaerosols (viruses) and dust. Desirable properties include high air permeability, high filtration efficiency, and effective facial sealing. The air permeability and filtration efficiency are determined by the microstructures of the layered fabrics. Characteristics of these microstructures include fiber orientation that influences the mechanical behavior, fiber tortuosity that provides a good understanding of the mechanism of fluid flow, and void space complexity in porous media, pore size, pore volume fraction, and pore tortuosity.
To quickly and easily obtain information about the mask microstructures, you need to visualize and analyze image-based data using software solutions.
Thermo Scientific™ Avizo™ Software allows researchers, academicians, and industry professionals to extract properties from image-based data, allowing them to develop safer, cleaner and stronger materials while controlling production costs from a single environment.
This paper focuses on the distribution of individual fiber orientations within a material. Experts from Thermo Fisher Scientific highlight three unique approaches that may operate at different resolutions to provide insights about the fiber orientations.
Image: Fiber length, orientation and density analysis of a 50% glass fiber-reinforced polymer (GFRP). Data courtesy of EMS Grivory.