An experimental and analytical study based on fractal theory of satin fabrics in unsaturated permeability

Prediction of relative permeability is important to avoid dry spots or micro voids in the liquid composite molding process. Most of previous studies focused on plain and twill, but few are about stain and none of them provide explicit equation to calculate accurate values of unsaturated permeability. The main purpose of this work is to first propose a new model which is proposed mainly based on fractal theory and has no empirical constant in the expression, to calculate the permeability of satin fabric. And then we employ a new experimental method to calculate the unsaturated permeability. Finally, a contrast experiment of 5-harness fabric and 8-harness fabric is designed at different injection pressures, and the accurate values of permeability are obtained. The results show that unsaturated and saturated permeabilities are in the same order of magnitude; furthermore, unsaturated permeability is 77% of saturated permeability in 5-harness fabric and 73% in 8-harness fabric.