Microscopy of Woven and Nonwoven Face Covering Materials: Implications for Particle Filtration.
Microsc Microanal
; 30(1): 27-40, 2024 Mar 07.
Article
em En
| MEDLINE
| ID: mdl-38252594
ABSTRACT
A suite of natural, synthetic, and mixed synthetic-natural woven fabrics, along with nonwoven filtration layers from a surgical mask and an N95 respirator, was examined using visible light microscopy, scanning electron microscopy, and micro-X-ray computed tomography (µXCT) to determine the fiber diameter distribution, fabric thickness, and the volume of solid space of the fabrics. Nonwoven materials exhibit a positively skewed distribution of fiber diameters with a mean value of ≈3â
µm, whereas woven fabrics exhibit a normal distribution of diameters with mean values roughly five times larger (>15â
µm). The mean thickness of the N95 filtration material is 1093â
µm and is greater than that of the woven fabrics that span from 420 to 650â
µm. A new procedure for measuring the thickness of flannel fabrics is proposed that accounts for raised fibers. µXCT allowed for a quantitative nondestructive approach to measure fabric porosity as well as the surface area/volume. Cotton flannel showed the largest mean isotropy of any fabric, though fiber order within the weave is poorly represented in the surface electron images. Surface fabric isotropy and surface area/volume ratios are proposed as useful microstructural quantities to consider for future particle filtration modeling efforts of woven materials.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Microsc Microanal
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos