HAIR STYLING PRODUCTS

Transcription

1 Development Team Principal Investigator Prof. Farhan J Ahmad Jamia Hamdard, New Delhi Paper Coordinator Dr. Javed Ali Jamia Hamdard, New Delhi Content Writer Mohammad Kashif Iqubal Jamia Hamdard, New Delhi Content Reviewer Dr. Sanjula Baboota Jamia Hamdard, New Delhi 0

2 2017 CONTENTS Introduction Required qualities and characteristics of hair styling products Basic ingredients for hair styling products Types of hair styling products Formulations Effect of Styling Products Packaging of hair styling products Evaluation of hair styling products Marketed hair styling products 0

3 INTRODUCTION Hair can be straight, wavy or curly, blonde, black, brown, red, gray, and white, and its natural variations are important to our identity. Hairstyle can be used to express personality and make a social statement. In order to achieve the desired appearance,various types of styling products and/or tools can be used. Manipulation of the normal structure of the hair shaft is universal, and it is dictated by multiple factors, including culture, religion, fashion, and even celebrities. Today, sales of hair care and styling products add up to a multibillion-dollar industry. 2. REQUIRED QUALITIES AND CHARACTERISTICS AND CONSUMER NEEDS From a consumer perspective, a quality hair styling product should possess the following characteristics: Easy to apply Easy to remove by shampooing Polymer-based products Non-flaky Non-tacky even at high humidity Rapid drying time Strong hold Emollient-based products Non-greasy, does not make hair look oily and lump Aids in hair manageability Improves shine Good smell Provides a long-lasting effect Does not damage the hair or scalp 1

4 2017 The technical qualities of hair styling, hair straightening, and waving products can be summarized as follows: Compatible with the other ingredients in the formulation Appropriate rheological properties Appropriate texture Appropriate ph Long-term stability Dermatological safety 3. BASIC INGREDIENTS FOR 3.1. Polymers Polymers are the main ingredients in all polymer-based formulations. They are responsible for holding the hair in the styled configuration and stiffening hair. i. The first polymer used was PVP, which is compatible with water and alcohol and has good film-forming properties. The main disadvantage of PVP is that it is sensitive to humidity, becomes sticky, and loses holding power when exposed to water. New polymers include PVP mixed with vinyl acetate (VA), which makes it more resistant to water. It is a valuable characteristic from styling perspective as it offers a stronger holding power; however, it can make hair more difficult to clean. Additional examples for polymers used today include other copolymers (i.e., a polymer made by reacting two different monomers), such as vinylpyrrolidone/ dimethylaminoethylmethacrylate (VP/DMAEMA) copolymer, octylacrylamide/ acrylates/ butylaminoethyl methacrylate copolymer, and vinylmethylether and maleic acid hemiesters (PVP/MA). ii. Mousses also contain polymers that act as both film-formers and conditioners. These ingredients are usually known as polyquaterniums, which are polymers with cationic cross-links. Due to their positive charge, they have greater substantively to the negatively charged hair fibers. 2

5 Anhydrous Base The anhydrous base provides a waxy, oily mass for the formulations. Ingredients of the anhydrous base also provide a hair conditioning effect, help reduce friction, and prevent damage. Examples for such ingredients include beeswax, petrolatum, lanolin, vegetable oils, mineral oils, and silicones Thickeners Thickeners provide viscosity control to the formulations; however, they are usually poor filmformers. They are most commonly hydrophilic ingredients applied primarily in gels. The concentration of these gelling agents is usually kept low in order to prevent them from coating the hair fibers and obstructing the adherence of the film-forming polymers. Additionally, thickeners used in such products are usually hygroscopic, which if used in high concentration can make the formulation absorb moisture from the air and cause softening of the polymer film and may also cause stickiness of hair fibers. Examples include polyacrylates, such as carbomer; cellulose derivatives, such as hydroxyethylcellulose; and polysaccharides Solvents Solvents dissolve the polymers and act as vehicles for the formulations. Examples of solvents generally used in polymer-based formulations include water and alcohol. Traditionally, aerosol products are based primarily on alcohol, while non-aerosol products contain water as well. Water was first added to lower the production cost; however, its use became more important when regulations on propellants were introduced. First, the increased level of water caused significant problems in product performance, including slower drying time and tackiness upon application. However, today s polymer systems are developed to work well with lower alcohol and higher water contents. 3

6 Propellants Propellants are essential ingredients in aerosol formulations, such as aerosol hair sprays and aerosol mousses. They help expel the content of the aerosol can. Examples include dimethyl ether, propane/butane, and fluorinated hydrocarbons Plasticizers Plasticizers make polymer films more flexible. Examples include dimethicone, castor oil, and mineral oil Sunscreens Sunscreens are often employed in hair styling products. They provide protection against UV radiation, help maintain the attractive appearance of the hair (as UV radiation can lead to weathering in the long term), and can also stabilize the viscosity of gels. Examples include benzophenone-4 and octylmethoxycinnamate Chelating agents Chelating agents provide protection against metal ions, improve the stability of gels, and increase the efficiency of preservative systems. The most commonly used chelating agents are EDTA and its derivatives Preservatives Preservatives provide protection against microbial contamination in water-based systems. Examples include the parabens and phenoxyethanol Additional ingredients can include humectants that contribute to the wet look provided by gels; conditioners, such as proteins and quaterniums; fragrances; vitamins; and herbal extracts. 4

7 TYPES AND DEFINITION OF 4.1.Polymer-Based Hair Styling Products Polymer-based products help improve the hair volume and height by increasing the hair strand stiffness and hair fiber interactions. They coat hair fibers with a thin film layer and form links between the fibers. Hair spray, styling gel, mousse, styling gum, and liquid setting products work based on this principle. i. Hair sprays are available in two major forms: aerosol products and non-aerosol products. Both types are usually applied to dry hair as a final step of styling the hair. Aerosol hair sprays are one of the most widely used hair styling products by both consumers and hair stylists. Aerosol hair sprays are released from the container with the help of a propellant, which results in very fine particles (such as a mist). Due to the small particle size of the droplets, they dry quickly. Non-aerosol hair sprays are dispersed from a plastic container supplied with a pump head. The distribution of the hair spray is provided mechanically by the pump head, which forms bigger droplets and, therefore, can wet the hair more rapidly. Hair sprays, especially those formulated to provide strong hold, tend to form flakes on the hair. ii. Setting lotions, also known as wave sets, are applied from a small bottle with a nozzle to towel-dried hair rolled onto curling rollers. Hair is usually dried when rolled up. Setting lotions coat the hair fibers and set them in a curled shape. After removing the curling rollers, the hair is combed gently into the desired style. Setting lotions do not work by sticking the hair fibers together, but by coating each hair fiber, creating greater interfiber friction, and reducing moisture uptake, thus conferring greater control to the hair. iii. Hair mousses are available in aerosol and non-aerosol forms; however, the aerosol types are far more popular. Both types are typically applied to towel-dried hair followed by drying and styling. They can also be applied to dry hair to create a wet, spiky look. Products applied to wet hair should provide easy combability, and therefore, mousses usually contain conditioner polymers as well. Mousses are designed to add volume, 5

8 2017 improve texture, and help control the hair mass. They can even be colored to provide natural or unnatural highlights temporarily. iv. Hair styling fiber gums, known as putties, are relatively new products designed to add increased hold to the hair. They are usually gum-like opaque emulsions. Fiber gums are more popular among younger customers with shorter hair. These products are bendable and moldable styling products that can be used to create various hairstyles, including spikes or a smoother look. Hair fiber gums are usually scooped from a jar and applied with the fingers. Fiber gums can be applied to both towel-dried and dry hair, depending on the look the user wants to create. v. Hair gels are also very popular hair styling products. They can offer both a smooth hold and an extreme look with spikes, depending on whether the product is applied to wet or dry hair and whether the hair is blow-dried or air-dried. Gels are usually applied from a tube or jar; however, spray gels are also available. Sprayable products usually have a lower viscosity, and they are easy to evenly apply to the hair and provide a weaker hold. Tube and jar gels have a higher viscosity, provide a stronger hold, and, therefore, allow for creating gravity-defying hairstyles. These products are also often referred to as sculpturing gels as they allow for creating spikes that naturally would not be able to hold its shape. Generally, the amount of film-forming polymer usually determines the hold level. Removal of a gel requires shampooing in some cases, a second lathering is recommended. Dry, brittle gels with high hold levels may tend to generate flakes when touched, similar to hair sprays Emollient-Based Hair Styling Formulations Emollient-based products can help smooth out frizz and increase hair shine by aligning fibers and reducing friction and can also have a conditioning effect on hair fibers. They work on the principle of depositing waxes and emollients on hair fibers. They are often used for thicker, curly, or kinky hair, which is hard to handle and can be very dry. Hair cream, wax, pomade, brilliantine, and oil spray work based on this principle. 6

9 2017 i. Hair pomades, also known as cream brilliantines, are anhydrous products based on petrolatum and various waxes. These formulations are generally very thick and are designed to straighten, condition, and moisturize the hair as well as add shine to hair while reducing frizziness. Pomades can be applied to both towel-dried and dry hair. As the products are quite thick, they are usually warmed up in the palms before being applied to the hair. ii. Hair brilliantinesare liquids based on oils and silicones. These products are designed to allow for easy styling and add shine to the hair without providing a greasy appearance. iii. Sprayable Oils and Silicones: Curly, kinky African-American hair needs hair sprays that contain a higher amount of oils and silicones to condition the hair and decrease the combing friction. These products are also known as oil sheen sprays. These are usually aerosolized oils that may also contain additional conditioning agents, such as proteins. These products are usually lighter on the hair; therefore, they can be applied on a daily basis. iv. Hair creams are emulsion products providing modest hold and high gloss. They may also be O/W or W/O emulsions, which break down easily on application. Creams can simply be oil in water emulsions with a 10-25% oil phase. The cream gel is a hybrid of the clear gel and an oil treatment or the emulsion. It can be a polymer-stabilized cream or simply a dispersion of oils, esters, or fatty products in a gelling matrix. The emulsion-stabilizing polymer thickener and stabilizer can be shear thinning for easier distribution and a lighter feel on the hands and the hair. The choice and concentration of esters, oils, silicones, fatty alcohols, or waxes determines the final feel and look of the product after dry-down. The higher the viscosity, unctuousness, or melting point of the oils and waxes, the greasier the feel will be on the hair after dry-down and perhaps during the wet application. The converse is true as lighter feeling, easier spreading oils are used. Styling polymers are also used in these formulas to supply some hold and counteract the oily effect of the oil phase. 7

10 FORMULATION OF 5.1. Formulation of Polymer-Based Hair Styling Products The formulation of low-viscosity products is relatively simple. Generally, ingredients are blended with agitation and mixed until homogeneous. During the formulation of a product containing thickening ingredients, dispersion of the thickener is a critical step. Thickeners are hygroscopic and tend to form clumps if added too fast to the dispersing medium or if no or slow agitation is used. As discussed in the previous chapters, certain thickeners need ph adjustment (neutralization) to reach their optimal viscosity. In such cases, the neutralizer should be added after proper hydration of the thickener in order to avoid clumping. The formulation of aerosol formulations must be performed in a flameproof area using special equipment. Formulation of the product concentrate is a solution preparation process. The concentrate contains polymers, neutralizers, plasticizers, fragrance, and other ingredients in alcohol or a mixture of water and alcohol as the vehicle. If the formulations contain water, it is usually added in the last step. Filling of the product concentrate and propellants in the aerosol cans is usually done via pressure filling. A general formula and formulation for Tack-Free sprayable lotion (low-viscosity) is represented in table 1. Table 1: Tack-Free Sprayable Lotion (Low-Viscosity). S. No. Ingredient % wt/ wt SD alcohol 40-B (anhydrous) Water Aminomethylpropanol Butyl ester of PVM/MA copolymer (50% active) Cyclomethicone (D5) Dimethicone (5 cs) Fragrance

11 2017 Add components in order listed. Very thin and sprayable product; dries without tackiness. A general formula and formulation for setting lotion is represented in table 2. Table 2: Setting Lotion. S. No. Ingredient % wt/ wt Water PVP K-30* Glycerin Cetrimonium chloride (25% aqueous) Oleth-20 and fragrance Diazolidinyl urea (and) iodopropynyl Butylcarbamate q.s * *PVP K-90 (1,300,000 MW) creates a significantly suffer product than the K-30 version (60,000 MW). The K-30 form can be sprayed, whereas the K-90 form cannot be sprayed. A general formula and formulation for heat waving lotion is represented in table 3. Table 3: Heat Waving Lotion. S. No. Ingredient % Monoethanolamine Potassium sulfite Potassium carbonate Ammonium carbonate Borax Sulfonated castor oil Water * Other polymers can be used, e.g., PVP/dimethylaminoethyl methacrylate, polyxquaternium-4, and many others in the category. A general formula and formulation for styling gel with UV screen is represented in table 4. 9

12 2017 Table 4: Styling Gel with UV Screen. S. No. Ingredient % wt/ wt Water Oleth-20 Dimethylpabamidopropyllaurdimoniumtosylate (and) propylene glycol stearate (65% active in water) PVP (K-30 powder) Propylene glycol (and) diazolidinyl urea (and) iodopropynyl butylcarbamate Triethanolamine (99%) Water Acrylates/steareth-20 methacrylate copolymer (30% aqueous) The preparation of styling gel with UV screen involves the following distinct steps: 1. Premelt and mix the dimethylpabamidopropyllaurdimoniumtosylate (and) propylene glycol stearate and add to the oleth-20 at 60 C. 2. Mix until clear and homogeneous. 3. Add to 55 C water and mix until clear. 4. Cool to C. 5. Add other constituents in order and de-aerate before adding the prediluted acrylates thickener. 6. Mix at least 30 minutes after clarity is achieved. A general formula and formulation for heat waving gel is represented in table 5. Table 5: Heat Waving Gel. S. No. Ingredient % wt/ wt Hydroxyethylcellulose WP 4400 Lithium hydroxide Sodium chloride Water q.s. to

13 Formulation of Emollient-Based Hair Styling Products The formulation of pomades is relatively simple. Liquid components are mixed with waxes and are melted to obtain a uniform mixture. All other ingredients are added to this mixture, and the resulting mixture is then is poured into appropriate containers. Hair brilliantines are generally mixtures of various liquid conditioning agents. Their formulation process consists of blending the various components until a uniform mixture is formed and filling them into containers. Hair creams are generally formulated as emulsions. A general formula and formulation for styling cream (reduced oil level) is represented in table 6. Table 6: Styling Cream (Reduced Oil Level). Ingredient Phase 1 Water Disodium EDTA PVM/MA decadiene cross-polymer Glycerin Phase 2 Glyceryl stearate (and) behenyl alcohol (and) palmitic acid (and) stearic acid (and) lecithin (and) lauryl alcohol (and) myristyl alcohol (and) cetyl alcohol Diisopropyladipate Isocetyl stearate Octyl palmitate Phase 3 Sodium hydroxide (1.0% solution) Phase 4 Phenoxyethanol (and) isopropylparaben (and) isobutylparaben (and) butylparaben Diazolidinyl urea (and) iodopropynylbutylcarbamate Fragrance % wt/ wt

14 2017 The preparation of styling cream (reduced oil level) involves the following distinct steps: 1. Phase 1: Add PVM/MA decadiene cross-polymer to water and heat to C. 2. Add glycerin and EDTA and mix for 40 minutes. 3. Melt and mix phase 2 at C. 4. Add phase 2 to phase 1 at C with high-shear homomixing. 5. Add phase 3 with homomixing. 6. Cool to C with sweep agitation and add phase 4. A general formula and formulation for cream gel (mechanically dispersed oil phase nonchemical hair relaxer) is represented in table 7. Table 7: Cream Gel (Mechanically Dispersed Oil Phase Nonchemical Hair Relaxer). Ingredient Water #1 Carbomer Glycereth-26 DMDMH (and) iodopropynylbutylcarbamate Diisopropyladipate Isocetyl stearate Dimethicone (gum/low molecular weight blend) Fragrance Water #2 PVP/VA (70% VP type, 50% active in water) Aminomethylpropanol % wt/ wt The preparation of cream gel (mechanically dispersed oil phase nonchemical hair relaxer) involves the following distinct steps: 1. Prepare carbomer in water #1 in main kettle. 2. Add other components; esters and silicones will float on top. 3. Dilute PVP/VA in water #2 and add neutralizer and additives. 4. Transfer PVP/VA phase to the main kettle and mix until gel is complete. 12

15 As neutralization begins, the oils are pulled into the gel. 6. Mixing will create a uniform mechanical dispersion of droplets of oil, which makes the gel opaque, and can be measured under the microscope to confirm uniformity throughout the batch. A general formula and formulation for Acid cold waving lotion is represented in table 8. Table 8: Acid Cold Waving Lotion. Activator % Glyceryl thioglycolate Thioglycolic acid ph-balancing solution Monoethanolamine (iron-free) Ammonium thioglycolate (50%, aqueous) Diammoniumdithiodiglycolate (40% aqueous) Sodium lauryl sulfate Fragrance Water QS 100 Mixing directions: At the time of application, 10 parts of the activator is mixed with 80 parts of the ph-balancing solution. A general formula and formulation for buffered cold waving lotion is represented in table 9. Table 9: Buffered Cold Waving Lotion. Activator % Ammonium thioglycolate (60% TGA) Ammonium hydroxide (28%) 1.70 Ammonium bicarbonate 5.00 Urea 2.50 Soluble lanolin 0.50 Fragrance 0.15 Water to 100 A general formula and formulation for No-Lye Hair Straightener is represented in table

16 2017 Table 10: No-Lye Hair Straightener. Ingredient % Component I: Part A Polawax Cetyl alcohol Stearyl alcohol PEG-75 lanolin Petrolatum Mineral oil Laneth-15 PEG-24 hydrogenated lanolin PEG-25 soy sterol Part B Water Polysorbate 20 Oleth Calcium hydroxide Polyquatemium-2 Component II: Propylene glycol Lithium carbonate Silica Titanium dioxide The preparation of No-Lye hair straightener involves the following distinct steps: 1. Part A is emulsified into Part  at elevated temperature to create Component I. 2. Component II is prepared by adding propylene glycol to the kettle and begins with moderate agitation with a high-speed Cowls disperser blade. 3. Add lithium carbonate slowly. 4. Continue disperser action and add silica and titanium dioxide. 5. Continue mixing for 30 minutes. 14

17 EFFECT OF STYLING PRODUCTS Styling aids not only assist in increasing volume and shine but are also useful in improving the appearance of hair dermatologic conditions that result in thinning hair, hair damage, or hair loss. People can damage and lose hair for various reasons, including illness, certain medications, and genetics; even harsh chemical treatments can also lead to severe damage or loss. In addition, thinning of hair can severely affect people s self-confidence and impact their quality of life and, in many cases, lead to significant psychological and emotional distress. Hair styling aids, such as hair spray and gels, can be used to lift thinning hair and create the illusion of fullness. Oil and silicone sprays can help restore shine and improve the appearance of very dry or even splitting hair. The ethnic hair care market is a blooming area in the cosmetic industry. Ethnic hair structure is unique and warrants special attention and care. The diameter of tight, curly, (or kinky) ethnic hair is much different from those of other hair types. Generally, African hair is coarser, very dry, frizzy and fragile, and more difficult to handle than Caucasian or Asian hair. Hair styling aids and various tools and techniques can be efficiently used to make the hair more manageable and smoother. Hair styling aids are, in general, safe for the skin and hair and can have many benefits. Consumers, however, often use more styling products than what they actually need, or they do not use the proper type of styling aid. Temporary and permanent hair waving and straightening are commonly used hair styling techniques, which are considered safe only if used carefully, selected according to the consumers hair type, and following the manufacturer s directions. Even the simplest tools, such as a curling iron, can lead to significant and permanent hair damage if used improperly. Both overuse and improper use of hair styling products and/or hair styling procedures and tools can have a negative effect on the hair s appearance. Here is a summary of the major negative effects of such products and tools on the hair and scalp, as well as the main factors that should be considered before altering the hair s natural appearance. 15

18 2017 i. Overuse of hair styling products based on film-forming polymers can create a weighted down effect, reduction in luster, or even appearance of white flakes. Flakes are tiny polymer particles peeling off from the hair fibers, which are similar to dandruff in appearance. ii. Overuse of emollient-based hair styling products can create a greasy, lump appearance, the opposite of what users are trying to achieve. iii. Regular and proper removal of hair styling aids is essential as these products accumulate on the hair fibers and provide a surface for additional dust and dirt. All these can lead to a dull, greasy appearance. iv. Irritation and allergic reactions to hair styling products are rare, similar to shampoos and conditioners. The main ingredients used in styling aids are generally not recognized as irritants. However, fragrances and certain preservatives added to these formulations may cause irritation reactions in sensitive skin patients. Heat can be efficiently used to temporarily reshape the hair into a desired form; however, very high temperature may lead to significant, irreversible damage of hair fibers.it has been observed that blow-drying and other heat treatments, such as curling irons or flat irons, can lead to cracks and bubble formation on the cuticle due to rapid dehydration of the hair fiber. These changes can permanently damage the hair, leading to visible changes, for example, loss in shine, weathering, and split ends. Permanent straightening and waving are chemical processes that involve breaking of the strong bonds in the hair and reforming them into a new shape. Improper steps in these potentially damaging chemical procedures can lead to significant hair damage, including loss of elasticity, loss of hydrophobicity; increased porosity; split ends; hair breakage; rough, dry, dull, and brittle hair; and even loss of the cuticle. In addition to hair damage, skin irritation can also commonly occur during permanent relaxing and waving of the hair. Many products used have a highly alkaline ph (around ph 12), which can lead to severe skin damage. 16

19 EVALUATION OF Quality Parameters commonly tested by cosmetic companies to evaluate the quality of their hair styling products as given below: 7.1. Stiffness of hair fibers Hair fixatives can significantly change the stiffness/ flexibility of hair fibers, which can be measured with a tensile meter. Stiffness is usually determined by the bending test (most commonly the three-point bending test). In this test, a hair tress is dipped into a hair spray solution or a diluted gel and is allowed to dry in a flat position. After drying, the bending stiffness is measured by fixing the hair tress horizontally on two arms and moving the central arm of the equipment vertically (applying the bending force to the hair tress). In the test, the force required to bend or break the polymer film is recorded, which refers to the bending stiffness force. Usually, stiffness is proportional to the viscosity of polymer solutions and the total amount of polymer deposited on the hair Fixative tackiness Non-aerosol polymer-based hair styling products, particularly those with a higher polymer concentration, often form actual droplets on the hair fibers, which stay tacky for a longer period of time and need longer drying time. Aerosol dispensers form fine particles, which tend to dry more quickly and produce a less tacky feel after application, making the hair spray easier to use. A slight amount of tackiness is usually expected by the users as a sign of proper working of the products. Too much tackiness will, however, cause the hair to stick to the brush/hands to a point of making it difficult to style. In the tackiness test, hair tresses are treated with a hair spray or other hair fixative and are evaluated by panelists. The time needed to indicate the absence of tack on hair is usually measured, which also refers to the drying time of the polymer film. 17

20 Dynamic hair spray analysis A new approach to measure multiple parameters of hair tresses is the dynamic hair spray analysis. This technique generally employs a commercial instrument, the texture analyzer. In the test, the hair tresses are shaped into an omega loop (i.e., formation resembling the Greek omega letter, Ω), while the two sides of the hair tresses are glued onto the surface). A probe moves down to touch the hair tress and deforms it to a predefined extent (i.e., 25%) and moves back; this movement is repeated a predetermined number of times. Initially, the untreated hair is evaluated, which is then sprayed with the test product and the hair tress is deformed again. The equipment measures stiffness and increase of stiffness after applying the hair spray, as well as tackiness and drying time. Various temperature and humidity values can also be employed in the measurement to see how these would modify the performance of the formulation Curl retention for long-lasting styling hold Polymer-based hair fixatives may claim long-term curl retention, which has to be substantiated. The test generally used is called the curl snap test. In this test, the hair fixative is applied to the hair tresses, which are then wrapped onto curlers and allowed to dry. After drying, the hair tresses are carefully removed from the curler and hung up to a support board. The initial length of the curls is recorded and then a wide-toothed comb is passed through the tresses. The length (lowermost portion) of the tresses is recorded, which can be used to calculate the curl retention of the hair fixative. Curl retention is calculated as follows: length of uncurled hair tress length of the hair at the time of reading %Curl retention = length of uncurled hair tress length of the curl at the start of the experiment Humidity resistance of treated hair tresses A number of hair fixative formulations claim high holding power even in humid environment. The test usually used is similar to the curl retention test. First, a hair fixative is applied to the hair tresses, which are then wrapped onto curlers and allowed to dry. After drying, the hair tresses are carefully removed from the curler and hung up to a support board. The initial length of the curls 18

21 2017 is recorded, and then they are placed into a high-humidity environment. The length is recorded at predefined time intervals, and then the curl retention is calculated based on the original length and final length as a percentage Flaking As discussed previously, overuse of polymer-based hair fixatives can lead to flaking. To test flaking, usually panelists are involved. The fixative is applied to the hair tresses and allowed to dry. The hair tresses are hung up onto a supporting board and a small-toothed comb is then passed through the hair tresses. The hair, comb, and area under the support stand are inspected and graded by panelists to evaluate flaking Performance parameters of permanent waving products In order to make sure that permanent waving products work properly without causing significant damage, their performance must be tested. The most common industry evaluation techniques are the DIT value, the curl length, and the 20% index. The DIT value is a measure of the tightness of the curl. Generally, the higher the DIT value, the better the performance of the perming solution and the tighter the curl. It is usually calculated using the following formula: DIT = diameter of the curl (mm) diameter of the rod (mm) diameter of the rod (mm) 100 Curl length is a measurement of the spring of the curl. Optimally, curls should be springy after being removed from the curling rod. The curl length is usually evaluated by fixing a fresh curl and observing its spring. The degree of laxity is proportional to the degree of hair shaft damage. Thus, longer curls are indicative of greater hair shaft damage. The 20% index is used to evaluate the strength of the permanently waved hair. This parameter is determined by stretching the freshly permed hair with a uniformly increasing load. The 20% index refers to the ratio of the load required to stretch a standardized wet hair tress to 20% of its original length after and before perming. The higher the index, the lower the reduction in hair 19

22 2017 strength after perming. Hair with a low 20% index will tend to break easily upon applying minimal trauma, such as combing. 8. PACKAGING OF The most commonly used packaging materialsfor hair styling products include the following: Plastic Bottles: Many hair fixatives are supplied in plastic bottles, usually with a flip-top cap or a pump head. Plastic and Metal Jars: Hair styling formulations, such as gels, creams, and waxes, may also be supplied in plastic or metal jars. Soft Tubes: Gels and creams can also be filled into soft-sided tubes with a screw cap or a flip-top cap. Aerosol Cans: Aerosol hair sprays and hair mousse are supplied in one-compartment cans, where the formulation and the propellant are mixed together. Aerosol containers can be made of tin-coated steel, tin-free steel, or aluminum. The material of the can is an important factor to be taken into consideration as the product with a certain ph, or certain solvents, may have an interaction with the can. Valve type is also an important factor to be considered; valve selection should address sprayability, clogging, and evacuation. 9. MARKETED BRAND TRESemmé TIGI Bed Head L oreal Paris Elnett Satin Himalaya Sunsilk MANUFACTURER Unilever, USA Unilever, USA L'Oréal, France The Himalaya Drug Company, India Unilever group, UK 20