Porosity in a Textile
Textiles for filtration

In a textile, the fibers are never in direct contact, and the spaces left between them are called “pores” or “porous spaces.” For a porous material, porosity is expressed as a volume percentage and is calculated as the ratio of the total pore volume to the total material volume. If we define the compactness of a filter ${\text{α}}_{\text{filtre}}$ as the ratio of the volume of material to the total volume of the yarn (Equation (11)), then the total porosity ${\text{ϕ}}_{\text{tot}}$ is given by: