Characterizing Visually Objectionable and Nonobjectionable Medullated Fibers in Mohair

Abstract

The objectives of this research were to determine and define the characteristics of visually “objectionable medullated” (i.e., “kemp type”) fibers and “nonobjectionable medullated” fibers in mohair and to establish which characteristic(s) best distinguish between them, when examining whole fibers, as opposed to fiber snippets, the latter having been the case in earlier research. It was found that the mean medulla to diameter ratio (Med Ratio) distribution of individual visually objectionable medullated whole fibers overlapped significantly with that of visually nonobjectionable medullated fibers, confirming previous studies on fiber snippets, that Med Ratio on its own does not represent a reliable criterion for consistently and accurately distinguishing between visually objectionable and nonobjectionable medullated mohair fibers. Taking fiber and medulla diameter, type and length into consideration in addition to Med Ratio did not appear to substantially improve the ability to differentiate between the two types of fibers. This aspect, together with the cellular nature of the medulla, will be the focus of future research.