Gelation of thermosetting prepreg by means of solid torsional method

A kind of glass fiber textile/epoxy prepreg and two kinds of carbon fiber textile/epoxy prepregs were studied by means of the solid torsional method, which provides a feasible measurement for the gel point and gelation process. The effects of the sample dimension and the type of fabric on the gel properties of the prepreg were investigated. The results show that the influence of the sample width on the gelation is negligible, while the increase of the sample thickness results in the decrease of the dynamic modulus, making the gel point less distinguishable. Textile fabric affects the gel point of prepreg significantly, so it demonstrates that the rheological property of prepreg is an integrated behavior of resin rheological property and the deformability of fiber bed.