An experimental study of the permeability and capillary pressure in resin-transfer moulding

This paper addresses issues of the inter-relationship between the permeability and capillary pressure in in-plane infiltration of assemblies of woven fabrics. Rectilinear infiltration experiments of assemblies of a plain-weave fabric at various low injection pressures were carried out to evaluate permeability and capillary pressure (Pc) for the woven fibre preform. Capillary pressure and the form factor, F, for the Young–Laplace equation were also estimated and a normalised capillary pressure was used to compare the Pc values found at different porosities. Regarding the estimation of permeability, it has been shown that the higher the injection pressure, the lower the associated error of not including Pc into the permeability calculation. When a corrected permeability was calculated taking into account the capillary pressure effect, the permeability proved to be independent of the injection pressure and the permeating fluid. An increase in permeability was found for pre-wetted fabrics in comparison to dry fabrics.