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Perm Wave
Chapter 20
Term | Definition |
---|---|
Cuticle | Tough exterior layer of the hair. It surrounds the inner layers and protects the hair from damage. |
Cortex | Middle layer of the hair, located directly beneath the cuticle layer. Is responsible for the incredible strength and elasticity of human hair. |
Medulla | INnermost layer of the hair, often called pith or core of the hair. Sometimes missing in fine hair. |
Disulfied Bonds | Strong chemical side bonds formed when the sulfur atoms in two adjacent protein chains are joined together. Not broken by water. |
Salt Bonds | relitively weak physical side bonds that are the result of an attraction between negative and positive electrical charges (ionic bonds) easily broken by chanes in pH, and they re-form when pH returns to normal. |
Hydrogen Bonds | weak physical side bonds that are also the result of an attraction between opposite electrical charges. Are easily broken by water (wet setting) or heat (thermal styling) and they re-form as the hair dries or cools. |
Permanent Waving | two-step process whereby the hair undergoes a physical change caused by wrapping the hair on perm rods, and then the hair undergoes a chemical change caused by the application of permanent waving solution and neutralizer. |
Alkaline Waves | Also known as cold waves, have a pH between 9.0 and 9.6, use ammonium thioglycolate (ATG) as the reducing agent, and process at room temperature without the addition of heat. |
Ammonium thioglycolate (ATG) | Is alkaline and is the active ingredient or reducing agent in alkaline perms. |
Glyceryl monothioglycolate (GMTG) | The main active ingredient in true acid and acid-balanced waving lotions. Has a low pH. |
True Acid Waves | HAve a pH between 4.5 and 7.0 and require heat to process. They process more slowly then alkaline waves and do not usually produce as firm a curl as alkaline waves. |
Acid-Balanced Waves | Has a pH of 7.0 or neautral. Because of their higher pH, they process at room temperature, do not require the added heat of a hair dryer, process more quickly, amd produce firmer curls than true acid waves. |
Exothermic Waves | Create an exothermic chemical reaction that heats up the waving solution and speeds up the processing. |
Endothermic Waves | Absorbs heat from surroundings. Activated by an outside heat source, usually a conventional hood-type hair dryer. |
Ammonia-free Waves | Perms that use an ingredient that does not evaporate as readily as ammonia, so there is very little odor associated with their use. |
Thio-free Waves | use an ingredient other than ATG, such as cysteamine or mercaptamine as the primary reducing agent. |
End Papers | Also known as end wraps. Absorbent papers used to control the ends of the hair when wrapping and winding hair on perm rods. |