Characterizing Visually Objectionable and Non-Objectionable Medullated Alpaca Fibers

It is recognized that visually objectionable fibers (VOFs) are undesirable in quality products because they appear lighter in dyed garments. Nevertheless, although a great deal of work has been done on mohair to characterize VOFs, this is not the case for alpaca fibers. Hence, this study was undertaken to characterize VOFs and visually non-objectionable fibers (VNOFs) in alpaca. Thus, a range of 52 alpaca fiber samples were obtained and visually separated into VOF and VNOF categories, and their respective cross-sectional, medullation, and average fiber diameter (AFD) characteristics were measured, analyzed, and characterized. The incidence of VOFs was found to be less than 2.5% by weight on average and was higher in adult alpacas than in younger ones (p < .05). Cross-sectional characteristics, degree of medullation, AFD, standard deviation of AFD, % of fibers ≥30 µm, and spinning fineness for VOFs were all greater than those for VNOFs. The correlations between AFD and the fiber cross-sectional characteristics were higher for VNOFs than for VOFs, except for ellipticity. The correlations between the cross-sectional characteristics and the degree of medullation were slightly lower for VOF than for VNOFs, except for ellipticity.