Published on January 13, 2008
Slide1: Hair Color Pigmentation Melanin : - produced by melanocytes during the growing phase (anagen) - spread out throughout the cortex, more near outer edge where it lies along the amino acid chains - does not protect from the harmful effect of sunlight - is found in 2 forms Slide2: - Eumelanin : dark pigmented which predominates in black and brunette hair/oval shape - Phaeomelain : lighter pigment, found in red and blond hair/smaller, partly oval and partly rod- shape Slide3: Melanin granules in the cortex of a hair Slide4: Range of color produced by melanins: yellow, brown, red, black Black hair: contains mostly eumelanin Grey hair: contains only little melanin White hair: contains no melanin Unpigmented hair: look yellow when they first grow (color of the keratin), later turn white Slide5: Seriously weathered hair: she needs to see a hair stylist, urgently! Slide6: This woman's coloration is typically Celtic: her hair pigment consists overwhelmingly of phaeomelanin, her skin is freckled and tends to bum easily, and her eyes are blue Slide7: Hair Care Hair condition: Good condition - shiny : ability to reflect the light - easy to manage - healthy appearance - just look good, shine and body Slide8: Factors that influence hair condition: - enough protein in diet (starvation or anemia due to lack of protein in the diet can damage the hair) - lack of protein: the color change from black to gingery-red - cuticles should be intact - cortex has not been affected by heat or chemicals - no cake with grease and old hair spray Slide9: Caring for your hair - regularly cleaning - using good quality products - remember to condition it well - cut regularly by skilled stylist - prevent weathering effects Slide10: - changing color by experienced hair technician - perming hair: improving condition first - after perming: more attention to conditioning your hair - don’t repeat the perm too often Slide11: Hair this long must have been growing for seven or eight years: just look at its beautiful condition Slide12: The straight blonde hair of this tanned young woman is naturally sun-bleached, and reflects light well Slide13: This man is head of a religious cult which requires its leader to be able to grow his hair long enough to reach the ground: his anagen period is probably around ten or twelve years. As he grows older and the anagen period shortens, he may lose his position The golden hair of the imprisoned fairy-tale princess Rapunzel was long enough to allow her lover to climb it in order to reach her in her tower - a demonstration not only of the length of anagen in Rapunzel, but also of the inherent strength of hair Slide14: Cosmetic Hair Treatment The most important treatments: Perming Coloring Stylist and technician: - expected to have a thorough understanding of: hair structure hair growth cycle continuing care of hair Slide15: - need a working knowledge of the disorders of the hair and scalp - knowing the chemistry of hair care products - the way in which they protect the hair Slide16: - the science that underlies the various cosmetic procedures - looking at the history of a client’s hair - examining the hair condition - deciding what is or is not possible to be done Slide17: Styling hair - temporarily or permanently altering its shape Slide18: Temporary - no chemical reaction in the hair - some weak hydrogen bonds are broken - re form in the newly positioned hair as the water evaporates by allowing wet hair to dry while twisted around the form - heat’s a great enemy of hair - dryer must be used with great care Slide19: - highest setting of a hair dryer will reach the temperature of boiling water - curls produced by setting are tight - all hair gradually absorbs moisture from the air - as the hydrogen bonds break it will in time re form and style will be lost Slide20: Perming Hair - disulphide linkages in hair are formed when the hair cells harden into keratin in the hair follicle - disulphide bonds keep the hair shaft in shape - disulphide bonds have to be broken down and re formed into different pattern - chemical changes to disulphide bonds are permanent Slide21: The history of perms - people have been trying to lure straight hair into waves and curls for thousand of years - only for temporary waving - first truly permanent waves became available in 1920 Slide22: - the waving lotion was activated by heat from an electrical device for each curl - no thermostat: heavy uncomfortable - perms were harsh, dry, tight frizzy curl difficult to manage Slide23: - in 1946, the “cold wave” was introduced - this was basically the perming process we use today - the unpleasant heat and weight of the old appliances were completely eliminated - the hair could be waved closer to the scalp Slide24: Modern perm - a permanent wave is a process that create a curl in the hair shaft by altering its internal chemical structure - the curls cannot be destroyed except by further chemical treatment - some hair can stand up to repeated perming quite well, some can’t Slide25: Factors that influence the perm - the basic nature of hair - its past history of chemical treatments - hair that has had a long history of perming combined with tinting or bleaching may have become so damaged as to be near the limit of what it will tolerate Slide26: pH and hair - alkali pH > 7 - acid pH < 7 - hair is swollen in alkali solution: the scales of the cuticle are lifted - in a slightly acid solution, the scales lie smoothly and soft - in a strong acid or alkali solution, the keratin protein starts to break down Slide27: An excellent example of 'setting‘ to give a spectacular effect to already curly hair Slide28: A perfect example of hair which has been given body and volume by perming Slide29: This permed and bleached long hair looks good at first glance, but the hair is dry and has no lustre Slide30: Dry, lifeless hair that has been repeatedly permed: the hair has also been bleached, and the darker roots are growing out in much better condition: at this stage it can no longer take a perm because virtually all the disulphide bonds have been broken Slide31: The perming process - hair is first washed, wound on to some kind of former - perm lotion (alkali lotion of pH~9) is applied - the cuticle slightly opens up - the lotion flows under the cuticle and into the cortex Slide32: - the lotion reacts with keratin of the cortex - disulphide bonds between protein chains are broken - the hair swells, soften and can stretch to take up the shape of the formers - after a while, the perm lotion is thoroughly rinsed - neutralizing lotion is applied and thoroughly rinsed Slide33: - the broken disulphide bonds are reformed - the hair is harden into its new shape * failure to rinse and neutralize properly can lead to many problems: scalp irritation and damage to the structure of the hair shaft Slide34: What happens during perming process? reducing agents in alkali lotion (ammonium thioglycollate) breaking disulphide linkage (joins the pairs of cysteine units) keratin softens and swells Softened hair is then put into its new shape Slide35: cysteine linkages slip past each other and realign themselves with new cysteine partners Neutralizing lotion is then applied (oxidising agents i.e. hydrogen peroxide) cysteine units link together into pairs again, hardening the hair and giving its new permanent shape Slide37: After perming - the hair continue to form new bonds for 2 or 3 days - the hair should not be shampooed during those few days - shampooing may interrupt this “curling” process: shampooing spoils the carefully constructed curls and could even lead to hair damage Slide45: Hair breakage at the back of the neck associated with relaxing and traction Slide46: Grossly over-permed hair: repeated perming will produce dry, damaged hair unless very expertly performed Slide47: Over-bleached hair: the damage is all too obvious Slide48: Relaxing (straightening) hair - the chemistry of relaxing process is identical to that of perming - breaking of disulphide linkages - reforming of the hair shape in a straighter arrangement - following by re-making of the linkage Slide49: This lady's hair has been gently relaxed Slide50: No comment needed!