CHAPTER CHEMICAL TEXTURE SERVICES - PDF
Chapter 20 Chemical Texture Services . Permanent waving is a two-step process whereby the hair undergoes .. These basic wrapping patterns may be combined in different ways to create a wide variety of specialized perm wraps that provide a base section at the point where the two rods meet in the previous row. Chapter 20 Chemical Texture Service Learning Objectives: Explain the structure and purpose of each of the hair's layers. Explain the chemical actions that take. Chapter 20 Chemical Texture Services . pH AND TEXTURE Chemical texturizers raise the pH of hair to an alkaline state to soften and sealthe hair shaft. 16 Side Bonds Disulfide: formed when sulfur atoms in two adjacent protein chains .. One of the best ways for you to obtain control of the texture of your client's overly.
LO4Demonstrate safe and effective perm techniques. LO5Describe how thio relaxers straighten the hair. LO6Describe how hydroxide relaxers straighten the hair. LO7Demonstrate safe and effective hydroxide relaxing techniques. LO8Describe curl re-forming and how it restructures the hair. Texture services can be used to curl straight hairstraighten overly curly hairor soften tightly coiled hair figure Cosmetologists should study and have a thorough understanding of chemical texture services because: Chemical texture services allow stylists the opportunity to offer clients options to change the texture of their hair and explore the fashionable world of hairstyling.
Knowing how to perform these services accurately, safely, and professionally will help build a trusting and loyal clientele. Knowledge builds confidence, to offer chemical texture services to all clients. Without a thorough understanding of chemistry, cosmetologists could damage haircause hair loss, and harm their clients and themselves.
Adding wave or curl to the hair. Removing curl or waves; leaving the hair smooth and straight. Curl re-forming soft curl permanents. Loosening overly curly hair ; changing tightly curly or coiled hair into loose curls or waves. The world of hairstyling is ever changing.
Chapter 20 Chemical Texture Service - Warren Woods Tower Cosmetology
Clients will always want to smooth their curly and wavy hair or give their straight hair more body and curl; therefore, mastering the techniques in this chapter will allow you to greatly expand your potential as a cosmetologist.
Tough exterior layer of the hair. It surrounds the inner layers and protects the hair from damage. It protects the hair from damage and makes it appear smooth and shiny.
It cannot adequately protect the hair against damage, so the hair becomes rough, dull, and prone to split ends and breakage. Middle layer of the hairlocated directly beneath the cuticle layer.
The cortex is responsible for the incredible strength and elasticity of human hair. Breaking the side bonds of the cortex makes it possible to change the natural wave pattern of the hair. The medulla does not play a role in chemical texture services and may be missing in fine hair.
The pH scale measures the acidity and alkalinity of a substance by measuring the quantity of hydrogen ions it contains. The pH scale has a range from 0 to A pH of 7 is neutral, a pH below 7 is acidic, and a pH above 7 is alkaline. The natural pH of hair is between 4. Chemical solutions raise the pH of the hair to an alkaline state figure This action opens the cuticle layer of the hair and allows the solution to reach the cortex layer, where restructuring occurs.
Coarse, resistant hair with a strong, compact cuticle layer requires a highly alkaline chemical solution. Porous, damaged, or chemically treated hair requires a less alkaline solution.
Keratin Proteins Keratin proteins are made of long chains of amino acids linked together end-to-end like beads. The amino acid chains are linked together by peptide bonds end bonds. These chains of amino acids linked by peptide bonds are called polypeptides. Keratin proteins are made of long, coiled, polypeptide chains, which in turn are comprised of amino acids. Side Bonds The cortex is made up of millions of polypeptide chains cross-linked by three types of side bonds: Side bonds are responsible for the elasticity and strength of the hair.
Altering these three types of side bonds makes wet setting, thermal styling, permanent waving, curl re-forming, and chemical hair relaxing possible figure Disulfide bonds are not affected by water; however, boiling water can break and alter their appearance.
Although the amount of heat used in conventional thermal styling does not break disulfide bonds, caution must be used when using thermal tools with extreme heat because the high heat can cause irreversible damage to the hair. Altering the chemical and physical changes in disulfide bonds makes permanent waving, curl re-forming, and chemical hair relaxing possible. Salt Bonds Salt bonds are relatively weak physical side bonds that are the result of an attraction between negative and positive electrical charges ionic bonds ; they are easily broken by changes in pH, and they re-form when the pH returns to normal levels.
Hydrogen bonds can be broken by water, whereas salt bonds are broken by changes in pH levels. Because chemical changes are involved, you should always perform an elasticity test before perming the hair figure The shape and type of curl are determined by the shape and type of rod and the wrapping method used figure Selecting the correct perm rod and wrapping method is crucial to creating a successful permanent wave. Perm rods come in a wide variety of sizes and shapes that can be combined with different wrapping methods to provide an exciting range of hairstyling options.
The Chemistry of Permanent Waving Alkaline permanent waving solutions soften and swell the hairand they open the cuticle, permitting the solution to penetrate into the cortex. Note the swelling of the cuticle layer. In figurehair from the same sample has been saturated with acid-balanced permanent waving solution pH 7. Note that there is far less swelling of the cuticle layer.
A reduction reaction involves either the addition of hydrogen or the removal of oxygen. The reduction reaction in permanent waving is due to the addition of hydrogen. The chemical process of permanent waving involves the following reactions: A disulfide bond joins the sulfur atoms in two adjacent polypeptide chains.
Permanent wave solution breaks a disulfide bond by adding a hydrogen atom to each of its sulfur atoms. The sulfur atoms attach to the hydrogen atom from the permanent waving solution, breaking their attachment to each other. Once the disulfide bond is broken, the polypeptide chains can form into their new curled shape. Texture services promote longer-lasting styles and make hair more manageable for the client at home.
Perms add volume and fullness for styling and especially help hair with a soft, fine texture. Perms also create greater control of hair that is coarse, wiry, and hard to manage. Cosmetologists skilled in the art of chemical hair relaxing are also in great demand today.
The service is used for clients of many nationalities who have extracurly hair.
Great strides have been made since the early days when people attempted to soften curly hair with a mixture of mashed potatoes, lye, and oil. Hair was also wrapped and twisted in an effort to straighten it. These unsophisticated techniques sometimes resulted in hair loss. Therefore, it is of extreme benefit to you as a student of cosmetology to become proficient in all these services. These skills will generate revenue and increase your profits when you enter the salon. A good cosmetologist can do hair, but a great one can perform all types of services on all types of hair with success.
Thorough hair and scalp analysis will be essential to creating successful styles using these chemical services. The process of chemical hair relaxing permanently rearranges the basic structure of overly curly hair into a straight or less curly form.
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- Chapter 20 Chemical Texture Services
- CHAPTER 20: CHEMICAL TEXTURE SERVICES
When done professionally, it leaves the hair relaxed and in satisfactory condition which can then be given a wide variety of styles. A professional relaxing service can literally be the difference between disaster and a dazzling finished look.
It represents the quantity of hydrogen ions and measures the acidity and alkalinity of a substance. Below 7 is acid. Above 7 is alkaline. Wet set breaks hydrogen bonds only. Perm breaks disulfide bonds that are stronger and more resistant. Perm softens hair to conform to new shape after wrapping. Uniform, even tension produces the resulting curl too much tension can mark or break the hair.
Straight rods have consistent diameter. Loop or circle rods fasten together to form a circle. End papers should extend beyond the ends of the hair to prevent fishhooks. It also refers to the directional pattern in which hair is wrapped: Wrapping against the natural growth pattern causes excess stress that may damage or break hair.
Acid solutions result in far less swelling of the hair than alkaline solutions. Reduction involves either the addition of hydrogen or the removal of oxygen. Disulfide bond is broken. Sulfur atoms attach to hydrogen from solution. A disulfide bond joins the sulfur atoms in two adjacent polypeptide chains. The permanent wave solution breaks a disulfide bond by adding a hydrogen atom to each of its sulfur atoms. The sulfur atoms attach to the hydrogen from the permanent waving solution, breaking their attachment to each other.
Once the disulfide bond is broken, the polypeptide chains can form into their new curled shape. Reduction breaks disulfide bonds Figure 20—31 and oxidation re-forms them.
Thio contains carboxylic acid and a thiol, which is a particular group of compounds. Thioglycolic acid, a colorless liquid with a strong, unpleasant odor, is the most common reducing agent in permanent waving solutions. The strength of the solution is determined primarily by the concentration of thio.
Stronger perms have a higher concentration of thio, which means that, compared to weaker perms, more disulfide bonds are broken. Because acids neither swell the hair nor penetrate into the cortex, it is necessary for manufacturers to add an alkalizing agent to the solution. The addition of ammonia to thioglycolic acid produces a new chemical called ammonium thioglycolate ATGwhich is alkaline and the active ingredient or reducing agent in alkaline permanents.
The degree of alkalinity pH is a second factor in the overall strength of the waving solution. Coarse hair with a strong, resistant cuticle layer needs the additional swelling and penetration that is provided by a more alkaline waving solution. By contrast, porous hair, or hair with a damaged cuticle layer, is easily penetrated and could be damaged by a highly alkaline permanent waving solution.
The alkalinity of the solution should correspond to the resistance, strength, and porosity of the cuticle layer. The chart depicts how perms can vary from being acid balanced to highly alkaline, depending on the type and formulation.
Because pH is calculated on a logarithmic scale, a pH of 7. Each client's hair has a distinct texture and condition, so individual needs must always be addressed. After a thorough consultation, you should be able to determine which type of permanent is best suited to your client's hair type, hair condition, and desired results. Table 20—1 lists the most common types of permanent waves, along with selected advantages and disadvantages for each.
These are only general guidelines. Just because a perm is indicated for use on color-treated hair does not mean it is safe for damaged or bleached hair. Also, hair that has been treated with a semipermanent color, which coats the hair, is more resistant than and not as porous as hair treated with permanent color. Most processing takes 5 to 10 minutes.