Hair Types and Required Specific Ingredients for Conditioning ...

Thin/fine and medium hair
Thin/fine and medium hair types are both represented by the Caucasian type, which is the most common
hair type in Europe. The mean diameter of adult Caucasian hair diameter is 50 – 90 µm; infant hair has a
diameter of about 31 µm [1].
Thin or fine hair may occur mostly in the northern part of Europe. The disadvantages of this hair type are
generally that the hair is often too smooth (like children’s hair), has a poor volume and exhibits “fly-away”,
especially in dry climates. If the hair fibers are electrostatically charged by combing or other means, it can be
nearly impossible to style the hair. Caucasian hair generally is just slightly curled; therefore a common
cosmetic treatment is perming. Bleaching and dying are also common treatments on this hair type.
With increasing age, a natural change occurs in the hair. The hair turns grey or white and becomes more rigid
and slightly thicker. Therefore grey or white hair is not classed as fine hair, but rather as medium hair.
Thick/coarse hair
Hair types with a wider diameter are represented by the Asian, the South American/Mediterranian and the African hair
types. Within this group the main distinction is the form of a cross section of the hair fibers. While Asian hair exhibits a
circular cross section, the other hair types are more elliptic. An African hair fiber is most elliptical, appearing as a band.
This structural form renders African hair more susceptible to mechanical damage. The degree of elliptic cross section
correlates with the curliness.
The Asian hair type is typically straight; therefore a common cosmetic treatment is permanent waving. In Asia,
bleaching and dying are also widespread treatments. In the Asian markets, hair coloring is generally done to lighten the
hair color. Grey coverage, which had not been common, is gaining in popularity.
The South American and Mediterranean hair types are quite curly. Here, straight hair with a low volume is desired.
Therefore, permanent straightening is an often-used cosmetic treatment. Permanent straightening is from a chemical
point of view a very similar process to waving. Therefore hair care needs are very similar for both types of damage.
The African hair type is very curly. If hair is very curly, this property dominates other fiber properties and controls hair
effects [1], and needs therefore very specific cosmetic treatments. When straight hair with low volume is desired,
chemical straighteners, which can damage the hair, are employed. Further damage is inflicted if the hair is subsequently
bleached or dyed to achieve a specific color.
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