HAIR TYPES & ETHNICITY (3)- Afro hair

The characteristics of Afro hair

One tends to associate Africans with tightly curled hair. However, some Caribbean people and aboriginal tribes in South East Asia and Australia also have this hair type. It tends to be woolly and dry with a flat cross section. The combination of black and red pigments in the hair result in hair color that is almost black to brown. About 10 percent of people have auburn hair.

Afro  hair shape and twisted structure is very vulnerable. It is extremely easily damaged by heat or chemicals. The hair bulb may lie to the side of the follicle, and so the hair shaft grows out of the follicle at an acute angle. Intermittent variation in diameter as the hair strand twists causes weak points along its length. Due to their curliness, the strands weave among each other and become entangled easily. Another reason for entanglement is some scales have loosened and broken off from the hair strands.  The disjointed scales along the hair strands become caught up with the scales on neighboring hairs. The result is tangles, producing knots that in turn become tightened during combing. Even vigorous combing can cause breakage in afro hair.

Hair become wavy when there is Irregular growth in the hair bulb     (the bulb varies slightly to one side or the other). Another factor is the shape of the hair follicle, whether it is straight or curved.  All hair twists as it grows. In Asian hair, the twists are far apart. Therefore, the curvature of straight hair is not pronounced. Some Afro hair has 12 times as many twists per centimeter as Caucasian hair. The number of twists of wavy hair is between that of straight and curly hair.

The thin cuticle of Afro hair is often in an open position. This allows moisture to escape from the cortex, leading to dryness.  Moisture contributes to the strength of hair. The open cuticles make the cortex vulnerable. Since the cortex provides hair its resilience, Afro hair is the most fragile among the three hair types. It breaks under a strain of 60 grams after an elongation of 40%. At the other end of the scale, Asian hair is the strongest, withstanding a weight of 100 grams and an elongation of 55%. The strength of Caucasoid hair is between the other two hair types.

* Photo from Wikipedia

HAIR TYPES & ETHNICITY (2)- Asian hair

The characteristics of Asian hair

Asian hair is Straight or slightly curved , thick and has tensile strength. It has the capacity for  a longer life span and  grow to greater length than other hair types.  If you cut the hair, the cross section is round.   It resists damage well due to its hair structure.

The hair bulb is the tiny factory that manufactures hair. It sits snugly at the base of your  hair follicle that supplies the bulb with nutrients and water through a fine mesh of blood vessels. The hair cells die in the mid- region of the follicle and formed into a hair strand. The hair shaft  then exits through the skin of the scalp.

In straight Asian hair, bulb, follicle and shaft are all aligned directly above each other. The hair grows straight out of the scalp. Therefore, if you cut the hair too short, the thick strands will stick out like bristles of a brush.

Asian hair has a thicker cuticle (the outer ‘bark’ that protects the center of the hair, the cortex). It has up to ten layers of these scale-like cuticles.

The cuticles are laid at a steep angle and are closer to each other, providing better protection to the cortex. However, the oily ‘glue’ that holds the cuticle together is not as strong as Caucasoid hair. If you pull or stretch the hair too much, the glue give way and the hair breaks of in a long strand but can holds its shape due to the strong cuticle.

When cuticles lie close to each other along the length of the hair (closed position), it reduces the amount of moisture from escaping from the cortex. Moisture within the hair give it strength and suppleness. The flip side is it is more difficult for nutrients and moisture to penetrate the hair. For those who wish to color or perm their hair, it is also more difficult for dyes or chemicals to penetrate.

The positive aspect of close cuticle is the hair looks glossier because it reflects light better. When the cuticles are open, the hair looks  dull and feels coarse. Since Asian hair has up to twice the number of cuticle layers than other hair types, they feel very rough when the cuticles are open.