ryanshope
Well-Known Member
Relaxing African- American Hair
In previous generations men of Afro-american extraction, particularly celebrities such as Nat King Cole and Sammy Davies Junior relaxed their hair for public acceptability. After the 1970s when exaggerated African styles (often requiring relaxing and re-perming) men currently tend to trim their hair to short African styles often with sculpting.
Chemical restructuring agents are now predominantly used by women. And by far the commonest hair "stlye " in women of African-American descent is to wear the hair relaxed.
An estimated 70% of women undertake this on a regular basis. This can only be achieved by chemical processing and straightens the hair allowing to be worn in "Caucasian" fashion or permitting less challenging curls to be formed by re-processing. The damage to the already fragile hair may be significant.
See below under Relaxing Chemistry
Relaxers
Chemical hair products that permanently straighten hair are called straighteners or relaxers. Relaxation of tight curly hair is normally achieved by application of 2-4 % alkali based relaxers. Most relaxers are formulated in the form of heavy creams consisting of very high oil-in-water emulsions which are combed through the hair where they slowly break down the structural bonds. The aggressiveness of the caustic is controlled by the incorporation of suitable emollient oils.
Relaxer Chemistry
Relaxers consist of three principal components: an alkaline agent, an oil phase and a water phase. Relaxers need a strong alkaline component; this may be sodium, potassium or lithium hydroxide, or guanidine hydroxide formed by the reaction of guanidine carbonate and calcium hydroxide. The oil phase contains a high concentration of oils as well as a surfactant. Because these lipid materials add sheen to the hair, ease combing and lend some barrier protection to the scalp, the oil phase can be considered a conditioning and protecting vehicle
Relaxers are the most popular method of straightening hair. The two most common types of relaxers are sodium hydroxide (lye) and guanidine hydroxide (no-lye). Also on the market are potassium and lithium hydroxide relaxers as well as ammonium bisulfite relaxers. However, sodium hydroxide and guanidine hydroxide have proven to be the most effective. Guanidine hydroxide relaxers are considered less irritating to the scalp than lye based relaxers; therefore, some consumers prefer them.
Comparison of Relaxer Types
Lye vs No-lye
relative strength
LYE: 3
NO LYE: 1
alkaline active
LYE: NaOH or KOH
NO LYE: guanidine hydroxide or lithium hydroxide
chemical agent
LYE: OH-
NO-LYE: OH-
pH
LYE: 12.5 - 14
NO LYE: 12.5 - 13.5
penetration and spreading
LYE: faster
NO LYE: slower
relaxer processing time
LYE: shorter
No LYE: longer
irritation potential margin
LYE: higher due to lower safety
NO LYE:lower due to a higher safety
drying potential margin
LYE: less drying to hair and scalp
NO LYE: more drying to hair and scalp
No-lye products, although considered less harsh, can still burn the scalp, eyes and ears.
This process is repeated every 2-3 months and is very harsh on the hair\and the hair loses much of its water-retaining capacity. Damage can result from either the reduction step (rearranger and booster) or the oxidation step (neutralise).
http://www.oxfordhair.org/index.htm
In previous generations men of Afro-american extraction, particularly celebrities such as Nat King Cole and Sammy Davies Junior relaxed their hair for public acceptability. After the 1970s when exaggerated African styles (often requiring relaxing and re-perming) men currently tend to trim their hair to short African styles often with sculpting.
Chemical restructuring agents are now predominantly used by women. And by far the commonest hair "stlye " in women of African-American descent is to wear the hair relaxed.
An estimated 70% of women undertake this on a regular basis. This can only be achieved by chemical processing and straightens the hair allowing to be worn in "Caucasian" fashion or permitting less challenging curls to be formed by re-processing. The damage to the already fragile hair may be significant.
See below under Relaxing Chemistry
Relaxers
Chemical hair products that permanently straighten hair are called straighteners or relaxers. Relaxation of tight curly hair is normally achieved by application of 2-4 % alkali based relaxers. Most relaxers are formulated in the form of heavy creams consisting of very high oil-in-water emulsions which are combed through the hair where they slowly break down the structural bonds. The aggressiveness of the caustic is controlled by the incorporation of suitable emollient oils.
Relaxer Chemistry
Relaxers consist of three principal components: an alkaline agent, an oil phase and a water phase. Relaxers need a strong alkaline component; this may be sodium, potassium or lithium hydroxide, or guanidine hydroxide formed by the reaction of guanidine carbonate and calcium hydroxide. The oil phase contains a high concentration of oils as well as a surfactant. Because these lipid materials add sheen to the hair, ease combing and lend some barrier protection to the scalp, the oil phase can be considered a conditioning and protecting vehicle
Relaxers are the most popular method of straightening hair. The two most common types of relaxers are sodium hydroxide (lye) and guanidine hydroxide (no-lye). Also on the market are potassium and lithium hydroxide relaxers as well as ammonium bisulfite relaxers. However, sodium hydroxide and guanidine hydroxide have proven to be the most effective. Guanidine hydroxide relaxers are considered less irritating to the scalp than lye based relaxers; therefore, some consumers prefer them.
Comparison of Relaxer Types
Lye vs No-lye
relative strength
LYE: 3
NO LYE: 1
alkaline active
LYE: NaOH or KOH
NO LYE: guanidine hydroxide or lithium hydroxide
chemical agent
LYE: OH-
NO-LYE: OH-
pH
LYE: 12.5 - 14
NO LYE: 12.5 - 13.5
penetration and spreading
LYE: faster
NO LYE: slower
relaxer processing time
LYE: shorter
No LYE: longer
irritation potential margin
LYE: higher due to lower safety
NO LYE:lower due to a higher safety
drying potential margin
LYE: less drying to hair and scalp
NO LYE: more drying to hair and scalp
No-lye products, although considered less harsh, can still burn the scalp, eyes and ears.
This process is repeated every 2-3 months and is very harsh on the hair\and the hair loses much of its water-retaining capacity. Damage can result from either the reduction step (rearranger and booster) or the oxidation step (neutralise).
http://www.oxfordhair.org/index.htm
