Measurement of transverse permeability using gaseous and liquid flow

Accurate measurement of transverse permeability is important for processes such as resin film infusion and vacuum-assisted resin transfer molding. In these liquid composite molding processes the out-of-plane flow is dominant and thus the transverse permeability is needed for flow prediction. This paper introduces an apparatus to measure saturated permeability for fibrous preforms using both gaseous and liquid flow. The setup creates a uniform one-dimensional flow through-the-thickness of the reinforcement by integrating a high permeability layer on the mold surfaces. A wide range of permeability as a function of fiber volume fraction can be measured in one experiment while applying a known load under a hydraulic testing machine. The system has been designed using process simulation. The measurements using the gaseous medium are comparable to the saturated fluid flow results. The measurement system can also be used to measure changes in dry fabric permeability prior to infusion due to debulking or application of binders on the fabric surface.