Abstract
An assumption is made in this paper that fabrics are consisted of two parts. One is a nozzle part such as spaces among yarns in woven or knitted fabrics. Another is a capillary part such as spaces among fibers in yarns. The air permeability of fabrics is considered to be the sum of the two factors.
The results show that the air permeability can simply be expressed by the relation beween the pressure difference of flow meter ΔPN and that of two faces of fabrics ΔP;
√ΔPN=A√ΔP+BΔP
where, A√ΔP and BΔP are the air permeability of a nozzle part and a capillary part respectively.
The experimental findings obtained by varying the air permeability by removing yarns and/or by oiling the fabric have revealed that the assumed model well corresponds to the construction of actual fabrics.
