Impregnation ability of polyimide into high strength carbon fiber bundle

On the assumption that an impregnation of polyimide using the filament winding method, the impregnating ability of polyimide into a PAN based high strength carbon fiber bundle was discussed. Polyimide precursor solution (Skybond 703) for the prepreg manufacturing process was diluted to control viscosity in a range from 0.01 to 1.41 Pa·s by n-methyl-2-pirroridon (NMP). Impregnation into a carbon fiber bundle (T 1000 GB-12000) was under atmospheric pressure. The impregnated bundle was heat to 343°C for imidization. The bundle was held vertically and also horizontally on a substrate. Fiber volume content of the prepared bundle was measured from the cross-sectional morphology by optical microscopy. When the impregnated bundle is laid level on a substrate buring the heating process, the viscosity of the precursor solution from 0.1 to 0.6 Pa.s must be adjusted to obtain the desired fiber volume content of 50-60 vol% for the carbon fiber reinforced polyimide.