The effects of fluid type and viscosity on the steady-state and advancing front permeability behavior of textile preforms

The effects of fluid type and viscosity on the permeability of both saturated and dry preforms were investigated. Fluids used were water, corn oil, and Epon 815, an epoxy resin. Preforms tested included style 167 E-glass, a plain weave E-glass fabric, and IM7/8HS, an eight harness satin carbon fabric. Two methods were used to measure the permeability of the textile preforms. The first, known as the steady-state method, measures the permeability of a saturated preform under constant flow rate conditions, The second, denoted the advancing front method, measures the permeability of a dry preform to an advancing fluid. Results from the two methods showed that fluid viscosity had no significant influence on the permeabilities of the two fabrics. Steady-state and advancing front permeabilities for the warp direction of the two fabrics were similar. In addition, advancing front permeability values were found to be similar for different fluids over a wide range of values for the capillary number. Contact angle measurements indicated that Epon 815 wets both fibers better than the corn oil. In addition, E-glass has lower contact angles with both fluids.