The Physical and Cosmetic Behavior of Hair

During the past few years, some improvement has been made in the understanding of single fiber properties. However, as indicated earlier, more progress has been made in the area of definitions and test methods for those hair assembly assessments that are important to consumers (i.e., cosmetic assembly characteristics). 

For the main discussion in this chapter, the physical properties of human hair have been divided into three categories  

Another important classification that will be referred to routinely is single fiber and fiber assembly properties. The more important single fiber properties are elastic deformations, friction, cross-sectional area (diameter), static charge, luster or hair shine, and cohesive forces. 

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