The permeability is one of the most important manufacturing parameters in fiber reinforced plastics (FRP) in which fibers are impregnated by resin. Although the permeability is defined by the Darcy's law, wettability between fibers and resin is not considered as a constituent parameter. In this study, we focused on the correlation between wettability and permeability in FRP. Wettability was controlled by the concentration of silane coupling solution for the surface treatment of fibers.
