Mechanical profilometry of wool and mohair fibers

In the scanning electron microscope, the surface of wool fibers is much rou gher than that of mohair or other specialty fibers, mainly due to differenc es in the frequency and height of the cuticle scales. In order to assess an d quantify these differences, which are essential for the perception of "ro ughness" and thus for fast fiber discrimination, mechanical profilometry is used to assess coarse Merino wool and Texas mohair fibers. The data are an alyzed by smoothing and Fourier analysis to separate cuticle-related effect s of roughness from longer term fiber diameter changes attributed mainly to the characteristic circadian (daily) biological rhythm of the animal. The results show that subjectively observed differences in the roughness of the two fiber types are reflected in roughness and frequency parameters obtain ed from their mechanical profiles, enabling reliable discrimination between wool and mohair.