Curls
As curling is called curled hair in humans. The term Locke has its origin in Germanic, from lukka . This actually referred to so-called tufts of leaves . In addition to Germanic, this can also be deduced from the Greek branch, branch .
Biochemistry and genetics
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Hair, regardless of its form, consists of filaments ("strands") of keratin . Keratin proteins are rich in cysteine (up to 17%; the unpleasant odor of compounds containing sulfhydryl groups in burned hair is known), glutamic acid (up to 13%), serine and proline (both around 9%) and have a helical shape Tertiary structure called α-keratin. Two of these keratin monomers combine to form a left-handed superhelix and two of these superhelices form a protofibril. Several protofibrils combine to form a microfibril, which is then grouped into bundles that form the macrofibrils of the individual hair. The high cysteine content enables stabilization both within individual keratins ( intramolecular ) and between several keratins ( intermolecular ) by means of cystine disulfide bridges (crosslinking).
Studies have found that curly hair is dominantly inherited (85–95%) in humans. The genetic issues are not yet fully understood, but results from 2009 suggest that mutations in the TCHH gene affect hair structure. The TCHH gene coding for the protein Trichohyalin that in the inner root sheath cells of the hair follicles expressed is. Trichohyalin makes the hair strong by being able to link with itself, with keratin and with other proteins of the inner hair root sheath. According to this study, trichohyalin without mutation (s) (especially without the leucine-to-methionine exchange in position 790) contributes to straight (instead of wavy or curly) hair. Whether the hair is straight, wavy or curly depends largely on the shape of the follicle it is forming. The rounder the follicle , the smoother the hair that has developed. The more oval the follicle, the curlier it is. In addition, the angle of the follicle tunnel to the skin surface contributes to the shape of the hair. If the tunnel is vertical, the hair comes out smoother, if it is inclined or even curved, the hair comes out more wavy or curly.
Cultural meaning
Early on, people tried to artificially curl their hair. Archaeologists have unearthed clay wadders in Egypt that show that the Nile was already 3,100 BC. Chr. Hair twisted into curls. The ancient Romans also used a method, they deformed the hair with the calamistrum , a tube into which a hot rod was inserted. In modern times, curls were brought into the hair with heated squeezing and papillot irons . In the 18th century, wigs were placed in boiling alkaline borax water , which created curls on the wig. Late 19th century Frenchman developed Marcel Grateau the Ondulier -iron for curls, but lasted only until the next wash. In Germany, the hair was wrapped in metal sticks protruding from the head and the hair was soaked in potash and rose oil, also an alkaline solution. This was then heated at 120 degrees for four to five hours and then cooled to fix it. Karl Ludwig Nessler introduced the permanent wave in London in 1906 . It was patented in 1910. From around the 1920s, hairdressers began to offer hair straightening frequently. Hairstyles such as the Conk , which was worn by many Afro-American celebrities such as Chuck Berry and James Brown , enjoyed particular popularity at this time . From the 80s onwards, other, gentler methods of curling or waving hair emerged, such as the Jheri Curl , which became famous through Michael Jackson , but the result is not nearly as consistent as that with perm.
Lock and smoothing methods
Hair curlers are essentially cylindrical objects that are used to wind up straight or slightly curled hair and to fix it in the wound state until the hair has assumed the desired shape or has dried. Hair curlers in the form of a flexible roll made of foam (seen in the picture on the right) are called papillots .
There are heating rollers, also called curling irons, which aim to use the heat to shape the curls. This is done by a wax core inside the heating coil, which warms up. Most heated hair curlers have an ion coating. This releases negatively charged ions to the hair structure, where it specifically counteracts static charges and reduces frizz. Before the industrial age, hair curlers were either made from wooden sticks or iron rolls (papillots) were used as such. Today hair curlers are extruded , injected , wound or manufactured using special processes. Most of the time plastics are used, but also aluminum , foam cords and brass wire .
Straighteners heat up like curling irons to shape the hair with heat. The areas that heat up are made of metal and often coated with ceramic plates. The hairline is first clamped between the ceramic plates and then the straightening iron is pulled towards the ends of the hair to straighten the hair.
Hot air brushes weaken the hydrogen bonds and remove the natural moisture from the hair. The hair can then be curled and waved. This dehumidification is basically only temporary. Most hot air brushes have a ceramic-coated brush head. This ensures even heat distribution. The hairstyle lasts for several hours. There is no permanent damage to the hair structure, as hot air brushes work with comparatively little heat and, unlike curlers and straighteners, do not attack the hair.
A permanent wave or cold wave is the term used to describe the chemical transformation in which straight hair is waved or curled.
Similar to the permanent wave, the so - called counter wave treats the hair with the same process, but instead of winding it up, rather pulling it straight. Hair products such as relaxers and texturizers are known and popular among Africans and Afro-Americans, which straighten their hair on a mostly alkaline basis (see Conk ).
See also
Web links
- Literature on hair curlers in the catalog of the German National Library
Individual evidence
- ↑ Locke. In: Wissen.de, dictionary of origin.
- ↑ New yearbook for mineralogy, geognosy, geology and petrefacts . Swiss Beard, 1835, p. 3.
- ^ NH Leon: Structural aspects of keratin fibers . ( Memento of the original from February 5, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF) In: J. Soc. Cosmet. Chem. , 23, 1972, pp. 427-445.
- ↑ SE Medland, DR Nyholt, JN Painter et al .: Common Variants in the Trichohyalin Gene Are Associated with straight hair in Europeans . In: American Journal of Human Genetics , 2009, 85 (5), pp. 750-755, doi: 10.1016 / j.ajhg.2009.10.009 , PMC 2775823 (free full text)
- ↑ straight vs. curly . Davidson College, an analysis of the publication in the American Journal of Human Genetics (2009).
- ↑ suffering Amarie Tirado-Lee: The Science of Curls , Helix Magazine, 2014.
- ↑ Permanent wave and counter wave - this is how it works! Retrieved May 22, 2020 (German).
