CUTICLE SCALE HEIGHT MEASUREMENT OF ANIMAL FIBERS BY SEM AND AFM

摘要

Mohair belongs to a class of animal fibers collectively called speciality fibers, due to the fact that these fibers are luxurious, rare and often expensive relative to sheep wool. South Africa produces more than 50% of the world total mohair production. The price differences between speciality fibers and wool is believed to be the major factor causing adulteration and mislabeling of textile products. The textile industry hence needs evaluation of the fiber composition of a fiber blend used in a textile product. This requires the development of a fast and reliable technique for the evaluation of fiber composition. Fiber identification previously relied upon light microscopy (LM) to examine the fiber surface for pattern and frequency of scales. However LM was found to be unsuitable for certain fiber blends namely wool/mohair and wool/cashmere hence the need for an alternative technique. Cuticle scale height (CSH) measurement by scanning electron microscopy (SEM) was found to be the most reliable method and led to the development of the IWTO 58-00 test procedure. This technique is based on the fact that wool has more pronounced scales than mohair and other specialty fibers like cashmere, alpaca, llama, camel hair, etc. In this study, CSH measurements obtained using SEM (as per IWTO 58-00) and an alternative technique using atomic force microscopy (AFM) are compared using standard statistical methods.