A simple network model was introduced to simulate fluid transport in terms of permeability in multi-laid nonwovens. For the simulation, the structure variables considered were porosity, the pore size and distribution of constituent layers, and the number of layers. All of these significantly affected fluid transport. At the neighboring pores in the multi-laid network structure, the smallest one determined the overall permeability. The increase in the number of layers produced decrease in permeability with the effective pore size in the nonwovens. The permeability of the multi-laid nonwoven decreased when the pore size distribution of the constituent layers were broader at a fixed number of layers. Quantitative simulation showed that the model developed in this research would be useful in designing multi-laid fibrous structure for optimum performance in absorbency, evaporation, moisture transfer, drainage, and filtering in their application to such nonwoven products as geotextiles, diaper sanitary napkin, filter, etc.
