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Hair and Fiber Microscopy (1207)


This is an introductory course for students wishing to acquire the theory, technique and skills to characterize and identify hairs and fibers at an advanced level. The emphasis of this course is on identification but other characteristics of this class of materials are also treated, especially with respect to properties that may help to individualize or source them. It is strongly recommended that the student has experience or previously taken the Applied Polarized Light Microscopy course, or the equivalent, before enrolling in this class.

Day 1
Introduction to the microscopy of fibers and hairs. The value and importance of reference collections and the best books and atlases of hairs and fibers. Morphology I: Hair. Microscopic anatomy of hair and the techniques for studying it in the laboratory. Distinguishing human from non-human animal hairs. Technique for the identification of animal guard hairs. Identification of animal fur hairs used as textile fibers. Human hair comparison characteristics.

Day 2
Types of man-made fibers, their production and effects on morphology and composition. Morphology II: the shapes of man-made fibers in longitudinal and cross-section. Whole mounts. Fiber inclusions, their identification and study. Technique for the preparation and study of cross-sections of single fibers. Introduction to the optical properties of fibers.

Day 3
Optical properties: Determination of refractive indices, birefringence and sign of elongation of fibers and their use in fiber characterization and identification. The standort diagram and its use in fiber identification. Determination of exact birefringence of high performance fibers. Correlation of optical properties, chemistry, crystallography and orientation of fibers.

Day 4
Morphology III: The woody and non-woody vegetable fibers. Microscopic anatomy of plant fibers. Technique for the study and identification of woody fibers. Technique for the study and identification of bast and leaf vegetable fibers.

Day 5
Other techniques for fiber characterization and identification. Hot stage microscopy. Microchemical tests and fiber identification dyes. Laboratory examination of known-unknowns.