Some geometrical singularities in the characterization of vapor grown carbon fibers using laser diffraction technique

Vapor grown carbon fibers (VGCFs) are the most promising potential substitutes for ex-PAN carbon fibers, because of their low cost. A standard tensile test for carbon fibers is not valid for several types of VGCFs because their thickness and very irregular morphology make it difficult to evaluate their equivalent diameter. After study of laser diffraction by Fourier transform, it is concluded that the diffraction patterns contain separate information about fiber diameter, in regular fibers, and fiber morphology.