抄録
The relation between the air permeability K of fiber assemblies unidirectionally oriented at high porosity ε was studied by applying the Darcy law to one-dimensionall air flow.
Experiments were performed with cotton fibers and polyester fibers in the porosity region of 96.0-99.9% when fiber-axes are parallel and perpendicular to air flow, and it was found that: K=Rε3/(1-ε)β where R and β are experimental constants depending on the kinds of fibers, fiber orientation and air flow direction.
The result does not agree well with the Kozeny-Carman law, but shows good agreement with the Lord's results obtained for cotton fiber assemblies in the porosity region of 96-99%.
