On the critical infiltration pressure model for situation of rough surface of carbon fibers

A roughness on the fiber surface is an important factor for critical infiltration pressure of a fiber bundle. A surface roughness parameter a was introduced in a well known infiltration model in this paper. The relationship among the pressure p, the contact angle theta and the roughness parameter a was studied. It is found that as theta = pi, the infiltration pressure decreases with increase of a. But in a wetting system such as theta = 0, infiltration occurs spontaneously whatever value a has.