Measurement of permeability of continuous filament mat glass–fibre reinforcements by saturated radial airflow

The measurement of fibre reinforcement permeability is important for the understanding, optimisation and modelling of RTM and resin infusion processes. This work investigates the use of a saturated radial air flow experiment for measuring the permeability of continuous filament mat (CFM), which is a common reinforcement type used for industrial RTM parts. The use of air, rather than liquid resin, is cleaner, quicker and potentially easier to control. The paper considers the problems inherent in using a compressible fluid, instead of a liquid, for the measurement of permeability, and the requirements for maintaining laminar flow. It describes the instrumentation used for flow and pressure measurement, and the effect of varying flow rate. Results compare favourably with published permeability values based on liquid flow experiments, and are independent of flow rate within the range of values investigated.