AFRICAN HAIR AND CURLY HAIR

Afro-ethnic hair presents variation of diameter at several points along the thread (the diameter at twisting points is smaller than at other areas), less water content, and most importantly, an ellipsoid shape. Hair fibers present torsions at many regions along the thread, while Caucasian hair has a cylindrical cross-section.

The small angle of the waves of very curly hair makes it more susceptible to breakage, when mechanically worked making curly hair more difficult to comb without provoking frizz. Although the production of sebum is high on African hair, curly and wavy hair they are more prone to have oily scalp but dryer hair fiber. Sebaceous glands of African descendants are frequently less active, when compared with the Caucasian ones, and they produce low amounts of sebum. This way, both scalp and threads are dry because they do not have good lubrication, even when the cuticle is preserved and the scalp tends to be less hydrated. Usually, the scalp is relatively dry in order to the naturally irregular distribution of sebum.[7] Distribution of sebum along the fibers by combing and brushing is a way of lubricating curly hair because of the natural difficulty of the sebum produced on the scalp to diffuse along the fiber.

To reach variety of styling, very curly hair is frequently straightened by pressing or by chemical relaxing/straightening. But, as the fiber is extremely sensible and prone to breakage it

is not unusual that curly and straightened hair do not achieve long length and breaks during the growing process.

Fine straight hair can transport sebum very well, and curly-coarse hair tend to minimize tress clumping and limpness. The use of conditioners and leave-on products decrease interfiber friction making hair easier to comb. Chargeability also decreases helping to improve dry combing.

The use of anti-dandruff shampoos can make hair more difficult to comb. High cleansing shampoos remove surface oils and increase chargeability by depositing small amounts of anionic surfactants onto the hair. Less flyaway is achievable by lubricating the fiber surface and decreasing static charge. Grooming a nonlubrified hair may lead to hair breakage. Abrasion and friction are impactant factors that cause hair damage by protein loss. The use of conditioners with oils and silicones are important to minimize the rubbing and friction of the cuticle cells for chemical treated hair and after the use of anti-dundruff shampoos. Black hair has less density than Caucasian hair. The number of hair follicles in Caucasians is 120.000 and in African descendants is 90.000. This is the way the African descendants may experience some feeling of hair loss after performing a hair straightening procedure because when the hair loses volume, the scalp may be exposed because of the lower number of hair follicles.