Abstract

Practices in the tanning industry may result in the occurrence of possible damage on the grain surface and grain layer that can spoil the quality of leather. The so called ‘large follicle defect,’ a natural damage associated with the characteristics of coat and the hair growth cycle, is a defect attracting the attention of researchers because of its morphological characteristic distribution and periodicity in wet-blue, semi-finished, finished, full grain and corrected grain leathers. Due to the lack of information on this defect in journals concerning leather making and to the need to understand the nature of the defect with the purpose of guiding process modifications to minimize its adverse effects, follicle rhythm and details are considered in this report. Knowledge of hair follicle activity and the correlation between coat shedding and the variation in environmental conditions during the seasons of the year consolidate the hypothesis that the defect is associated with the natural process of hair shedding. This is particularly observed in the phase during which shedding reaches its maximum levels and it is related to the hair deeply anchored in the grain layer during the progress of the Telogen and the Anagen phases (evolution of the shedding hair and expulsion of inactive hair).