Definition and Measurement of Crimp of Textile Fibers

Two fundamental concepts are defined, the effective crimp diameter and the effective wave number. The corresponding figures for these concepts are calculated from the measurements of the width values of the plane projection of a rotating fiber and from the measurements of the crimp ratio. These figures are obtained for a fiber under a certain load, and take into account the spatial nature and the statistical aspect of crimp. An effective curvature is determined as well. Results are obtained for 90's Merino and 52's Scotch-Blackface wool fibers. It is shown that the higher quality wool fibers are associated with lower effective crimp diameters and higher effective wave numbers.