Effects of the Inter-Yarn Pores on the Moisture and Air Permeability of Textile Fabrics

The effects of the inter-yarn pores on the moisture and air permeation through textile fabrics were investigated by the water method and KES method for three kinds of fabric groups, spun yarn fabrics and filament yarn ones as well as stainless steel meshes. Their moisture permeability measured under various environmental humidity conditions at 20°C were discussed in relation to the pore size of the sample. The bi-logarithmic plot of the mean area per pore and the moisture permeability per unit pore area showed a linear relationship with a negative gradient, the line of which shifted in parallel toward a region of higher permeability as the environmental humidity was decreased. Comparing the moisture permeation behavior of the sample fabrics under the same condition revealed that the permeability was larger in the order of the steel mesh group, the spun yarn fabric group, and the filament yarn fabric one. Similar relation of order was found also in the slope of the linear dependency above. The relations between the pore size and air permeability of the fabrics were also studied together.