What is the machine used to straighten hair?

Hair styling tool with heating element

historical image of hair irons (top)

A hair iron or hair tong is a tool used to change the arrangement of the hair using heat. There are three general kinds: curling irons, used to make the hair curly, straightening irons, commonly called straighteners or flat irons, used to straighten the hair, and crimping irons, used to create crimps of the desired size in the hair.

Most models have electric heating; cordless curling irons or flat irons typically use butane, and some flat irons use batteries that can last up to 30 minutes for straightening. Overuse of these tools can cause severe damage to hair.[1]

Types of hair irons

[

edit

]

Curling iron

[

edit

]

An electric curling iron

Curling irons, also known as curling tongs, create waves or curls in hair using a variety of different methods. There are many different types of modern curling irons, which can vary by diameter, material, and shape of barrel and the type of handle. The barrel's diameter can be anywhere from .5 in (1.3 cm) to 2 in (5.1 cm). Smaller barrels typically create spiral curls or ringlets, and larger barrels are used to give shape and volume to a hairstyle.

Curling irons are typically made of ceramic, metal, Teflon, titanium, tourmaline. The barrel's shape can either be a cone, reverse cone, or cylinder, and the iron can have brush attachments or double and triple barrels.

The curling iron can also have either a clipless, Marcel, or spring-loaded handle. Spring-loaded handles are the most popular and use a spring to work the barrel's clamp. When using a Marcel handle, one applies pressure to the clamp. Clipless wands have no clamp: the user simply wraps hair around a rod. Most clipless curling irons come with a Kevlar glove to avoid burns.

Straightening irons

[

edit

]

Straightening irons, straighteners, or flat irons work by breaking down the positive hydrogen bonds found in the hair's cortex, which cause hair to open, bend and become curly. Once the bonds are broken, hair is prevented from holding its original, natural form, though the hydrogen bonds can re-form if exposed to moisture.[2] Straightening irons use mainly ceramic material for their plates. Low-end straighteners use a single layer of ceramic coating on the plates, whereas high-end straighteners use multiple layers or even 100% ceramic material. Some straightening irons are fitted with an automatic shut off feature to prevent fire accidents.

Early hair straightening systems relied on harsh chemicals that tended to damage the hair. In the 1870s, the French hairdresser Marcel Grateau introduced heated metal hair care implements such as hot combs to straighten hair. Madame C.J. Walker used combs with wider teeth and popularized their use together with her system of chemical scalp preparation and straightening lotions.[3] Her mentor Annie Malone is sometimes said to have patented the hot comb.[4] Heated metal implements slide more easily through the hair, reducing damage and dryness. Women in the 1960s sometimes used clothing irons to straighten their hair.

In 1909, Isaac K. Shero patented the first hair straightener composed of two flat irons that are heated and pressed together.[5]

Ceramic and electrical straighteners were introduced later, allowing adjustment of heat settings and straightener size. A ceramic hair straightener brush was patented in 2013.[6] Sharon Rabi released the first straightening brush in 2015 under the DAFNI brand name. The ceramic straightening brush has a larger surface area than a traditional flat iron.[7]

Crimping irons

[

edit

]

Crimping irons[8] or crimpers work by crimping hair in sawtooth style. The look is similar to the crimps left after taking out small braids. Crimping irons come in different sizes with different sized ridges on the paddles. Larger ridges produce larger crimps in the hair and smaller ridges produce smaller crimps. Crimped hair was very popular in the 1980s and 1990s.[9]

See also

[

edit

]

References

[

edit

]

Hair styling technique

"Blowout (hairstyle)" redirects here. For the haircut with short sides and a long top, see Blowout (haircut)

Large rollers can be used to straighten curly hair

Hair straightening is a hair styling technique used since the 1890s involving the flattening and straightening of hair in order to give it a smooth, streamlined, and sleek appearance.[1] It became very popular during the 1950s among black males and females of all races. It is accomplished using a hair iron or hot comb, chemical relaxers, Japanese hair straightening,[2] Brazilian hair straightening, or roller set/blowdryer styling. In addition, some shampoos, conditioners, and hair gels can help to make hair temporarily straight.

The process is often called "rebonding" in some countries from Southeast Asia (e.g. Indonesia, Singapore, Malaysia and Philippines). If done often, flat irons and chemicals can be damaging to hair.[3] Excessive straightening often results in split ends.[3] However, heat protectant sprays can decrease the damage.[3]

Methods

[

edit

]

Temporary (non-chemical)

[

edit

]

Hair being straightened with a hair iron.

Hair irons and hot combs used appropriately temporarily modify the shape and texture of hair. The hair will tend to revert to its original form due to environmental factors, mainly contact with water from washing, rain, humidity, etc. This includes water in styling products such as gels applied after straightening, although careful use of such treatments can produce usable results.

Use of too much heat, or for too long, can cause heat damage, irreversibly altering the hair's structure. Use of protective sprays or lotions before heat styling may help to prevent heat damage. While the damage cannot be reversed, it can be disguised using various styling techniques. Only cutting off and regrowing damaged hair removes the damage.[4][5][6]

There are five principal tools used for hair straightening without chemical treatment:

• Straightening comb (also known as a hot comb) which applies heat to the hair.[7]
• Hair irons (flat iron) apply heat directly to hair. For shorter hair, a flat iron with heating plates that are around 0.5 to 1 inch wide are used. Wider hair irons are used for longer hair.
• Blow dryer with a comb attachment or round brush to straighten hair. Too much heat can cause damage to the hair; a low to medium heat level protects it and the scalp. Adding some rinse-free or leave-in hair conditioner could help moisturizing hair while using a blow dryer to heat.
• Large hair rollers can be used on damp hair to stretch and straighten the hair as it dries. Often large rollers are used before blow-drying to minimize heat damage.
• Electrically heated hair straightening brushes produce heat that is absorbed by the hair by steadily brushing it. The hair must penetrate deep into the brush for maximum effect.

A popular temporary straightening method is the Dominican blowout which originated in the Dominican Republic. The technique spread to the United States where it was popularized by Dominican stylists. The Dominican blowout allows highly-textured and tightly-curled hair types to be straightened without the use of chemicals. It has become popular, particularly among African Americans, as an alternative to permanent hair straightening or as a method of straightening the hair between relaxers.[8]

Permanent (chemical)

[

edit

]

Relaxers and the other methods permanently alter the structure of the hair, although new hair growth is not affected. The drug interferon alpha has been reported as being shown to modify hair follicles causing permanent change in a person's hair texture.[9] Chemical hair straightening uses chemical substances to break disulfide bonds, also called an S-S bond or disulfide bridge, in the hair shaft.[10][11]

There are several ways of permanently straightening hair. The main methods used today are:

• Keratin/Brazilian treatment - In this treatment a layer of keratin is added to the hair, followed by a hot flat iron. The keratin treatment is considered safe for hair since it uses the natural protein found in the hair shafts and is suitable for most hair conditions. The treatment straightens the hair, reduces frizz and adds a shine. The results last approximately 6 months and gradually returns to the original texture.
• Japanese/thermal reconditioning/yuko/rebonding - a non-coating treatment that loosens the cysteine bonds in the hair by application of a chemical for 15-20 minutes, and then a heat is applied to restructure the bonds into a straight type.
• Relaxers/chemical straightening - Chemical relaxers break hair’s disulfide bonds. Lye relaxers contain sodium hydroxide, while non-lye relaxers contain calcium hydroxide and can be used on more sensitive scalps.

Comparison of the permanent hair straightening treatments: Keratin/Brazilian treatment Japanese/Thermal treatment Chemical straightening/ hair relaxing treatment method keratin layer + flat ironing bond breaking chemical + heat + neutralising chemical hydroxide substance to break the disulfide bonds texture & appearance soft, silky, shiny, easy to manage. Lasts 2-6 months. silky straight hair. Permanent. soft, straight, easy to manage. Permanent. suitable for all hair types, damaged and previously treated hair that has not been treated with chemicals before; loose to medium curls coarse, tight curls safety concerns

• emits gases, not recommended while pregnant
• protection for skin and eyes is required

• damage from long exposure to heat
• might cause scalp irritation and hair loss

• chemical burns
• hair breakage

duration of treatment 2-4 hours 4-8 hours varies recommended hair care

• no washing, ponytails, or clips for 3 days
• using Sodium chloride free shampoo and conditioner
• Keratin shampoo

• no washing for 3 days
• use moisturizer and sun protection
• wait 1-2 months until dying the hair

deep conditioning

Cancer risk

[

edit

]

Relaxers can contain carcinogens such as formaldehyde-releasing agents, phthalates, and other endocrine-disrupting compounds,[12] according to National Institutes of Health studies. The compounds can mimic the body's hormones, and studies have found them to be linked to breast, uterine, and ovarian cancers. For example, a 2017 study found that women who used chemical relaxers were nearly twice as likely to develop breast cancer as those who did not.[13][14][15]

Afro-textured hair

[

edit

]

Madam C. J. Walker (1867–1919), popularizer of the straightening comb

Hair straightening using a hot comb or relaxer has a long history among women and men of African American descent, reflected in the huge commercial success of the straightening comb popularized by Madam C. J. Walker and other hairdressers in the early 1900s.[16] The Madam Walker System of Beauty Culture focused more on hygiene and healthy scalps and hair than hair straightening. Her vegetable shampoo and Madam Walker's Wonderful Hair Grower (an ointment that contained sulfur) were designed to heal dandruff and severe scalp infections that were very common during a time when most Americans lacked indoor plumbing, electricity and central heating. Walker did not invent the hot comb, which was commercially available in Europe and America as early as the 1870s. While the practice has at times been a controversial issue in discussions of racial identity, visits to the hair salon have become embedded in black culture, fulfilling an important social role especially for women.[17][18]

See also

[

edit

]

References

[

edit

]