Recently, the hair care industry has taken interest in targeting products according to ethnic demographics, to respond to unique needs. In the U.S., ethnic hair products are sold in designated areas of retail stores to make the process of finding appropriate niche products more convenient. Moreover, this has initiated a discussion regarding which hair types fall under the umbrella of “es typically quite wavy or curly as well.1
Beneath the ethnic hair umbrella are various ethnicities that present diverse hair fiber compositions, which require unique products. For example, straightening pthnic.” For example, again in the U.S., ethnic hair refers to hair of African or Hispanic descent that is very curly. Central American and South American hair types, e.g., Brazilian, Colombian, Venezuelan, etc., also could be included, as hair from these descents iroducts based upon guanidine hydroxide, sodium hydroxide and ammonium thioglycolate are frequently used to straighten African-American, Brazilian, Colombian, Venezuelan and Hispanic hair having wavy or very curly textures. Similarly, shampoos with 1% to 1.50% levels of cationic polymers are used to cleanse and detangle wavy/very curly hair. Such detangling shampoos, if used daily on straight Caucasian hair, will leave a polymeric residue buildup. Thus, a comprehensive review of the differences in hair fiber dimensions among straight, wavy and curly/coily hair is necessary to guide formulators as they develop products that cater to unique hair type needs.
Fiber Diameter vs. Shape
In the literature, hair fiber diameter has been identified as the distinguishing factor to classify fibers as fine, medium or coarse. Assuming the hair fiber is cylindrical in shape, this system remains appropriate across a variety of populations. Asian or Oriental and straight Caucasian hair, for example, tend to be more cylindrical.