Modeling and Analyzing Liquid Wetting in Fibrous Assemblies

A statistical model, the Ising model, is used to simulate liquid wetting of fibrous assemblies. The adhesive energy between fiber and liquid and the cohesive energy within the liquid are calculated by applying the Lifshitz theory under the assumption that the interactions between a fiber cell and a liquid cell and between two liquid cells are dominated by Van der Waals forces. The work of extrinsic force, the surface tension, is taken into account by its contribution to the energy of the system. To test the validity of the model, wicking experiments involve a set of polypropylene filament yarns with the same yarn count but different fiber finenesses. Computer simulations are also made to show the relationship between the traveling height of the liquid front in the fibrous assemblies and the time taken. Experimental and simulation results show considerable accord.