Shampoos
Shampoos are products of the chemical industry , but are also produced in a natural form ( natural cosmetics ). They are mostly creamy or liquid and usually perfumed . In addition to cleaning and degreasing the scalp hair (through the use of surfactants ), a shampoo also promotes the improvement of combability and hair shine, has building, firming, sometimes refreshing and other positive effects, such as B. pH neutrality , increased degreasing or less flaking . Shampoos are classified as cosmetics and personal care products .
The expressions shampoo , Schampo (o) n or Schampu are often in English as a replacement for the term shampoo used. The term shampoo [ ʃæmˈpuː ], which is also used in English , is derived from the Hindi word चाँपो [ tʃɑ̃ːˈpoː ] and originally referred to a head massage that was carried out with various vegetable oils and vegetable powders ; Similar terms are also found in other North Indian languages.
Today , shampoos , together with soap , shower gel , deodorant and water, form the core of many people's daily personal hygiene . The “no-poo” movement, on the other hand, is closely linked to environmental awareness. Regular use of shampoo is rejected.
In addition to liquid shampoo, there are also solid shampoo and hair soap . Solid shampoo contains less water than liquid shampoo and, as an additional ingredient, starch , which acts as a thickener. In contrast to conventional shampoos in plastic bottles, solid shampoos do not need plastic packaging or other costly packaging.
history
Historically, water and, if necessary, ordinary soap were initially used to wash hair. Due to its alkaline pH, however, it was not well tolerated by the scalp and the mucous membrane of the eyes. In addition, soap with calcium ions from the water formed lime soap , which left the hair dull and dull after washing. After washing with soap, a second rinse was made with dilute acetic or citric acid .
In the 19th century, English hairdressers made the first shampoos from soap flakes with water and herbal additives that gave the hair shine and fragrance. Kasey Hebert is currently the earliest known manufacturer of shampoos. There have been commercially available shampoos since the beginning of the 20th century. As early as 1903, Hans Schwarzkopf was marketing a powdered shampoo in a Berlin pharmacy. In 1927 Schwarzkopf developed the first liquid shampoo.
In 1932, alkyl sulfates came onto the market as a replacement for soaps . They are less alkaline and less sensitive to hardness than soaps. Until the 1960s, shampoos were sold as white powder in paper bags or as cream in tubes (" Schauma " from Schwarzkopf, "Smyx" hair detergent from Olivin-Wiesbaden).
With the development of the alkyl ether sulfates in the 1960s, there were very skin-friendly products for cleaning hair for the first time. Together with the development of plastics and plastic packaging bottles, inexpensive and good hair care products were now available for broad sections of the population.
application
When using, approx. 10 g of shampoo are distributed on wet hair while rubbing with fingertips on the scalp, so that a fine-bubble foam is formed. After a short exposure time, rinse thoroughly with warm water. The skin fat formed in the sebum glands and the inorganic salts, amino acids, urea and lactic acid, skin particles, environmental dirt and possibly residues of hair cosmetic treatments that emerge from the sweat glands with water should be removed in this way.
In Germany, women use an average of 2 to 20 grams of shampoo per wash.
Product requirements for shampoos
Depending on the selling price, a hair shampoo contains higher quality raw materials or inexpensive ingredients. A shampoo should meet the following requirements:
- Good hair cleaning effect
- Insensitive to water hardness
- Skin tolerance
- Foaming power
- Biodegradability
- Good effect on the hair (smoothness, shine, nourishing effect)
Composition of a shampoo
Although it "only" serves the purpose of cleaning, a shampoo is a complex product that is tailored to a specific group of buyers. It consists of approx. 10 to 20, in individual cases up to 30 recipe components, which fulfill their function in very different concentrations. In addition to water, the laundry raw materials usually form the main component. You are responsible for cleaning, the essential product performance. In addition, the so-called auxiliary or active substances form the second and third groups. A shampoo is usually composed of the following components:
Important surfactants in the shampoo
The main surfactant enables the real action of the shampoo - cleaning the hair. Surfactants increase the solubility of dirt and fat deposits in the hair in water. As washing-active substances (WAS) find exclusively anionic, such. B. alkyl sulfates , alkyl ether sulfates and amphoteric surfactants use. In addition to water, the surfactants usually form the main component of the shampoo.
-
Alkyl
sulfates Alkyl sulfates were the first synthetic shampoo surfactants. They are still used today. They have good cleaning and foaming properties . Their disadvantageous properties, such as sensitivity to water hardness , poor cold solubility or incomplete skin tolerance , can be compensated for by mixing them with other surfactants. -
Alkyl
ether sulfates Alkyl ether sulfates are insensitive to water hardness and also more skin-friendly than alkyl sulfates. They are often used in combination with alkyl ether sulfates, which consist of double or triple ethoxylated lauryl and myristyl alcohol . -
Alkyl
ether carboxylates Alkyl ether carboxylates are among the mildest surfactants. However, their foaming power is poor, so they are used in combination with alkyl ether sulfates. -
Protein-fat condensates
Protein-fat condensates have very good skin-friendly and hair-care properties, but more preservatives are required. -
Sulphosuccinic
acid esters Sulphosuccinic acid esters are quite mild for the skin and have a good foaming effect. -
Alkyl
polyglycosides Alkyl polyglycosides are the only nonionic detergent raw materials. They are better skin-friendly than all ionic surfactants and have favorable surfactant properties.
Co-surfactants
A co-surfactant complements the effects of the main surfactant. By using co-surfactants, the concentration of the main surfactant can be reduced, which reduces the risk of hypersensitivity for the user.
Film maker
Film formers, often from the group of polyquaternium compounds, form a cohesive layer on the surface of the hair. The plastic-like film should protect the hair and make it easier to comb. However, these substances also mean that shampoos can hardly leave stains that can be removed from textiles. Some shampoos also contain silicones as film formers (often recognizable in the list of ingredients by the ending "-cone").
Perfume oils & dyes
These components only serve to enhance the product's sensory properties. Dyes and fragrances should z. B. make the product more attractive to the consumer. By combining different perfume oils, odors occurring in nature should either be imitated or new scent effects, so-called fantasy notes, created.
Tiny crystal flakes made from fatty acid esters (such as waxy glycerine distearate) and fatty acid alkanolamides are used for the opaque “pearlescent luster” that reflects the incident light well .
Preservatives
Due to the high water content, shampoos must be protected from attack by microorganisms. This is the job of the preservatives or biocides . In the case of a special composition (e.g. high surfactant content), preservation may be dispensed with. Although microbiologically pre-tested raw materials, auxiliaries and active ingredients are now used, manufacturers are recommended to add antimicrobial substances so that changes to the cosmetics during storage can be excluded and the minimum shelf life can be observed. The State Office for the Environment, on the other hand, recommends in complete contradiction: "Avoid products with antimicrobial substances".
Urea condensates, p- hydroxybenzoic acid esters ( parabens ), phenoxyethanol , methyldibromoglutaronitrile , benzoic acid and salicylic acid are used for preservation .
In the past, formaldehyde was often used as a preservative. Since it is not considered to be harmless due to its skin-irritating potential and it has a bad reputation with consumers, it is increasingly being avoided. It must be declared from a concentration of 0.05%.
Complexing agents
Metal ions (iron ions) can get into the shampoo during production. Complexing agents (ethylenediaminetetraacetic acid, nitrilotriacetic acid), which bind the ions , are added to prevent undesired reactions of the dyes and perfumes with these ions .
buffer
Phosphate or lactate buffers are often used to stabilize the stability of the pH value of the formulations, with the aim of protecting the skin, hair and pH-sensitive components.
UV absorber
So that the dyes possibly contained in the shampoo are not decomposed by light, stabilization can be carried out by UV absorbers, especially in the red and blue areas. For this purpose, light protection filter substances such. B. benzophenone or camphor derivatives are used.
Flushing
By the term rinse ( hair rinse , hair conditioner ) or Conditioner ( engl. Rinsing , conditioner ) refers to a hair care product which after washing out the shampoo in particular the hair is applied lengths. Shampoo (which is usually in the alkaline range ( pH value > 7)) opens the hair flakes for cleaning, while the subsequent rinse closes them again due to its acidic pH value (<7) and adds fat . A conditioner is supposed to improve the combability, shine and structure of the hair.
Modern hair conditioners usually contain humectants , proteins , acid regulators , oils , surfactants , lubricants , antistatic agents and preservatives .
Making a shampoo
| Typical shampoo recipe | ||
|---|---|---|
| ingredient | Salary in% | function |
| water | 72.7-85.7 | solvent |
| Ammonium lauryl sulfate | 10-20 | primary detergent |
| Lauramide DEA | 3-5 | Foam stabilizer |
| Sodium chloride | 0.5-1.5 | Thickener |
| Perfume | 0.5 | Fragrance |
| Disodium EDTA | 0.2 | Complexing agents |
| Methyl paraben | 0.08 | Preservatives |
| Propyl paraben | 0.05 | Preservatives |
| β-naphthol orange | 0.002 | dye |
| Tartrazine | 0.001 | dye |
During the production of a shampoo, all ingredients are mixed in a suitable sequence in the warm or at room temperature (cold production). It may be necessary to melt, dissolve or mix raw materials beforehand and only then add them to the basic batch. The setting of the "setpoints", such as B. pH and viscosity take place after mixing. The product can then be filled.
The preparation of the batch is discussed in more detail below: The main components of the shampoo, water and washing raw materials, are placed in a steel kettle with a stirrer and, if necessary, heated to 60 ° C to 70 ° C. One after the other, further raw materials are added and stirred until homogeneous. If solid substances, such as waxy substances, powders or dyes, are to be added, these must first be melted or dissolved in water or other recipe components. If polymer care substances or thickeners are to be added, they may have to be pre-swollen in warm water. The perfume oil is optionally beforehand with a solubilizer, e.g. B. a nonionic surfactant mixed. The most common solubilizers include hydrogenated and ethoxylated castor oils. Since perfume oil and preservatives are often temperature-sensitive, the temperature of the shampoo preparation must not exceed 35 ° C when they are added. Finally, the pH is adjusted using an acid, e.g. B. citric acid or a base, e.g. B. caustic soda. This setting influences the viscosity of the shampoo. Therefore, the desired viscosity is then obtained by adding electrolytes, preferably sodium or ammonium chloride or sulfate. Even in low concentrations, these cause a strong increase in viscosity.
Continuous production takes place as cold production, in which all raw materials are conveyed into a static mixer via piston pumps .
Special shampoos
For oily hair
With increased fat production by the sebum glands of the fatty skin, the hair quickly becomes straggly, oily and the hairstyle becomes unsightly. In men, the higher sebum production is particularly promoted by the hormone testosterone. Sometimes environmental and psychological factors also lead to increased sebum secretion. Young people tend to have more problems with greasy hair than older people. To avoid such an effect, there are shampoos with a protein-abietic acid condensate and plant extracts containing tannins (e.g. oak bark extract). It has not been proven that very frequent hair washing stimulates the sebum glands to secrete more fat and thus leads to rapid regreasing of the hair.
For dry hair
If the hair still looks brittle, dull and dry several days after shampooing, you need to choose a shampoo for dry hair. The sebum glands produce too little fat. The care substances make it easier to comb, make it more supple and prevent the hair from “flying”. Care substances are vegetable oils, lecithin, lanolin, protein hydrolysates, collagen and keratin hydrolysates.
For damaged hair
Hair can be damaged by UV radiation, by cosmetic treatments (permanent waves, hair coloring), by the influence of chemicals (acids, bases), combing and brushing. Damaged hair cannot be restored to the condition of healthy hair. Nevertheless, shine and combability can be halfway achieved with special hair care products. Hair care shampoos for damaged hair contain the same active ingredients as for dry hair, but in a higher concentration. The use of a hair setting agent , masks (care) and hair oils are also recommended .
For flaky hair
In addition to the normal cleaning effect for hair and scalp, an anti-dandruff shampoo should remove loose skin flakes from the scalp and prevent the formation of visible flakes when used continuously, as these are viewed as unaesthetic on the scalp, but above all on clothing and as a sign of insufficient care . In recent times, practical tests over an application period of 6 to 8 weeks have shown that the growth-inhibiting effect against fungi (fungistatic effect) in particular is the cause of the reduction in dandruff with anti-dandruff shampoos. The composition of an anti-dandruff shampoo usually hardly differs from a shampoo for normal hair. Only other or additional active ingredients such as climbazole , piroctone olamine or selenium sulfide are used. However, their concentration is usually in the lower percentage range.
Color shampoos
A color shampoo or color protection shampoo should keep the color brilliance of colored hair longer. In the test carried out by Stiftung Warentest in March 2012, however, all 16 products tested scored "poor". The color shampoos are just as ineffective in this regard as a mild baby shampoo. They also do not protect better against UV radiation.
Baby shampoos
Baby shampoos are particularly kind to the skin and mucous membranes. Nonionic surfactants are used, as well as protein hydrolysates and chamomile extract. The pH value of a baby shampoo is skin-neutral, 5.5, so as not to attack the skin's natural protective acid mantle.
Dry shampoos
It is a powdered substance, sometimes plain rice flour and fragrance, that can be used to clean hair without adding water. The powder absorbs the oil from the hair. After a short exposure time, the powder can be brushed out of the hair. Nowadays, the use of dry shampoo has become uncommon. Use is essentially limited to emergencies, for example if there is not enough water (e.g. on hikes lasting several days) or if you are unable to wash your head due to an illness. Dry shampoo is still often used in animal fur care.
Caffeine shampoos
The caffeine contained in caffeine shampoos is used against androgenetic alopecia , the hereditary hair loss. In hereditary hair loss, the hair roots are hypersensitive to a metabolite of the male sex hormone testosterone , dihydrotestosterone , or DHT for short. Hair loss and baldness are the result in up to 80 percent of all men. The caffeine complex is supposed to counteract the negative effect of testosterone and lengthen the growth phases of the hair roots.
Others
Some of the active ingredients of shampoos are now also contained in shower gels, so that only one care product is required for skin and hair. There are also shampoos for pets , which are often used medicinally, for example with additives against ticks or lice .
Legal
As with all cosmetics, the declaration of ingredients according to INCI (International Nomenclature of Cosmetic Ingredients) has been mandatory for shampoos since 1997 . This should give allergy sufferers in particular the opportunity to check a product for questionable ingredients before buying it.
According to the Food and Feed Code (LFGB), a shampoo is a cosmetic product and is therefore subject to this law. Furthermore, the Ordinance on Cosmetic Products ( KosmetikV ) provides information on permitted substances, such as B. Colors, preservatives and UV filters. Cosmetic products must be labeled with a best-before date if this is less than 31 months. From a formaldehyde content of more than 0.05%, according to the Cosmetics Regulation, the note “contains formaldehyde ” must be applied to the packaging.
literature
- Wilfried Umbach: Cosmetics - development, production and application of cosmetic products. Georg Thieme Verlag, Stuttgart 1988, ISBN 3-13-712601-0 .
- André O. Barel, Marc Paye, Howard I. Maibach: Handbook of Cosmetic Science and Technology. Informa Healthcare, New York.
- Günter Vollmer, Manfred Franz: Chemical products in everyday life. dtv, 1985, ISBN 3-423-03276-6 , p. 176 f.
Web links
- Text of the Food and Feed Code
- INCI database haut.de
- Cosmetics - Ingredients - Functions (PDF) IKW
Individual evidence
- ↑ a b c d e f g h i j k l m n Wilfried Umbach: Cosmetics - development, production and application of cosmetic products. Georg Thieme Verlag, Stuttgart 1988.
- ↑ E. Schulze zur Wiesche: Modern hair care products. In: Practice of the natural sciences, chemistry. Issue 6, 2006, p. 14.
- ^ Hermann Römpp: Chemistry of everyday life. 23rd edition. Kosmos Franckhsche Verlagshandlung, Stuttgart 1976, p. 131.
- ↑ The cosmetic giants know exactly how to shower. Welt Online , June 27, 2014.
- ↑ a b H. Aebi, E. Baumgartner, HP Fiedler, G. Ohloff: Cosmetics, fragrances and food additives. Georg Thieme Verlag, Stuttgart 1978.
- ↑ Page no longer available , search in web archives: Problematic preservatives (section: detergents and cleaning agents) (PDF) Bavarian State Office for the Environment.
- ^ André O. Barel, Marc Paye, Howard I. Maibach: Handbook of Cosmetic Science and Technology. Informa Healthcare, New York.
- ^ A b Günter Vollmer, Manfred Franz: Chemical products in everyday life. dtv Verlag, Stuttgart 1985, p. 171.
- ↑ How does shampoo work for oily hair? Stiftung Warentest reader question.
- ↑ Color shampoo test by Stiftung Warentest In: magazine test. 4/2012 and on test.de, March 29, 2012.
- ↑ The shampoo pH can affect the hair: Myth or Reality? Retrieved March 16, 2016 .
- ↑ Food and Feed Code in the version published on April 26, 2006, last amended by Article 12 of the law of February 26, 2008.
- ↑ Cosmetics Ordinance in the version published on October 7, 1997, last amended by Article 1 of the Ordinance of May 15, 2008.