Hair Glossary: Structure & Fundamentals
Posted by All-Nutrient Professional on Feb 28, 2017
When you think of master colorists, what are some of the first words that come to mind? Talented of course, but how else would you describe them? Creative? An artist? A visionary? While all three are absolute yes's, what about a scientist?
There is so much chemistry involved with haircolor that in order to truly master the art, you must master the science behind it as well. Understanding the structure of hair is essential in understanding the process of haircolor. This is what makes our haircolor so special and what sets us apart. Because we are the manufacturers of our haircolor, we are also the chemists behind it. We know what the hair needs in order to obtain long-lasting and healthy haircolor. We look beyond the surface of the hair and into what is actually happening inside each strand during a chemical service. If you don't know the "how" of haircolor, how are you supposed to know the "what?" We put together a glossary of terms you need to know in regards to hair structure and chemistry so that you can better understand the entire process of haircolor.
Fundamentals
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Protein - Hair is comprised of 90% of a protein called Keratin. Keratin proteins start with the alpha helix, which fabricate into proto, micro, and macro fibrils, and into the cortex. The hard fibrous protective shield of the hair is also Keratin.
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H20 - Moisture aids in the body and stretch of the hair during chemical services, by helping the hair swell and contract. The 2 most noted problems with moisture balance is, Over-Moisturized or (Hyperhydrous) and Under-Moisturized or (Hypodhydrous).
Over-Moisturized hair appears limp, lifeless, has little body or fullness, and will not hold a curl or style for long periods of time. Excessive moisture in the hair will affect the hydrogen bonding or color penetration. Too much moisture will cause the hydrogen bond to overextend and reduction of bonding will occur.
Under-Moisturized hair feels dry, brittle, frizzy, and has little stretch or pliability. Moisture deficiency in the hair will also affect the color service. Without the presence of enough moisture the color could be uneven or fade off the dry areas of the hair.
- Essential Fatty Acids – Essential Fatty Acids make up 2-4% of the hair. They give the hair 50% of its sheen and preserve hair’s elasticity and flexibility. When Essential Fatty Acids are depleted, the hair will feel rough and dry and lack elasticity and pliability.
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Vitamins & Minerals - The actual structure of the hair is a makeup of vitamins and minerals. Our bodies receive these through the foods and supplements we consume. We can associate several conditions of hair loss and other related problems to: diet, illness, stress, medication, and genetics.
Structure & Chemistry
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Follicle – The follicle is the pore in the skin from which a strand of hair grows.
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Cortex – The cortex is the middle layer of the hair shaft where melanin is found.
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Melanin – Melanin is the pigment of hair located in the cortex of the hair shaft. Hair color is determined by the amount of melanin in the cortex. The more melanin; the darker the hair, the less melanin; the lighter the hair.
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Cuticle – The cuticle is the outermost, protective layer, or layers, of the hair shaft. The cuticle of the hair determines the level of porosity in the hair. It is made up scale-like cells that provide up to 1/3 of the hair’s strength. These layers can vary due to race, texture, density, and color. Caucasian hair has 7-9 layers, African American has 10-14, and Asian hair has up to 16 layers. With age the cuticle becomes less pliable and harder, which is why is can be resistant to color. The cuticle of fine hair can also become very compacted, resulting in difficulty penetrating the hair during chemical services.
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Alpha Helix – The alpha helix is made up of protein molecules to form the institute of a single hair. Beginning with the atom and the action in the cell structure, Protein molecules link together to form the Alpha Helix. Three alpha helices are twisted together to form a Protofibril.
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Protofibril – A Protofibril is the first fibril structure of the hair. Nine Protofibrils are bunched in a circle around two or more to make what is known as an eleven-stranded rope called a Microfibril.
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Microfibrils – Microfibrils are entrenched in an unstructured, unorganized protein of high sulphur. There are hundreds of microfibrils fixed in an unbalanced bundle, which is called a Macrfibril.
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Macrofibrils – Macrofibrils make up the main body of the cortex. The cuticle of the hair protects Macrofibrils.
Bonds
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Hydrogen Bonds – Hydrogen bonds are responsible for the ability of hair to be stretched and return back to its original shape. They allow us to change the shape of our hair temporarily with the aid of water. These bonds are electrically controlled and are responsible for approximately 35% hair’s strength.
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Salt Bonds – Salt bonds are Ionic bonds responsible for approximately 35% of the hair’s strength.
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Cystine Bond – Cystine bonds are also known as disfulide bonds, sulfur bonds, or just S-bonds. It is responsible for the hair’s toughness or abrasion resistance. It actually holds the hair fiber together. This is what enables us to permanently wave the hair.
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Peptide Chain – A peptide bond is a sugar bond that holds the peptide chain together by connecting amino acids, which gives hair toughness. Some moisture is contributed to the hair as a by-product of this bonding.
Topics: hair care, The Truth Behind