Fiber and Hair Analysis

Microspectrophotometry of Fibers and Hairs

Microspectrophotometers are used to analyze pigments, dyes and substrate materials of textile fibers and dyed hairs.

Textile fibers are prevalent in all aspects of our lives. They are used in everything from clothing to floor coverings to umbrellas and much more. The substrate of the fiber consists of either natural, such as cotton or wool, or man-made materials, such as Nylon™ or Rayon™. For most products, the fibers are colored either with dyes or with pigments which can either be adsorbed on the surface or inside the fiber substrate material itself. Additionally, there are specialty materials that may be added. Examples of these are ultraviolet absorbers (UVA) to protect a fabric from solar damage.

UV-visible-NIR microspectrophotometers, such as the 20/30 PV™, are used to analyze the dyes and pigments in both hairs and fibers. This is done by studying the absorbance and fluorescence spectra of these microscopic samples. Microspectrophotometers are also used to identify the polymers contained in man-made fibers. This is done by examination of the ultraviolet absorbance spectra to identify the polymer.

Dyed hairs can be animal or human hair. There are many different types of chemistries and they have many different effects on the hairs themselves. These are analyzed in the same manner as textile fibers. Interestingly, only dyed hairs are analyzed. The reason for this is that the color of natural hair changes along the length of the hair shaft. The cause may be anything from stress in our lives to sun or even swimming in the ocean. While dyed hair also shows variations along the length of the hair, it is not as dramatic. In fact, this variation can be mapped with the CRAIC FiberPro™ to learn more about the long term stability of hair dyes, for example.