CN117279540A

CN117279540A - Device for shaping hair

Info

Publication number: CN117279540A
Application number: CN202280033717.9A
Authority: CN
Inventors: L·克拉里苏; 桑迪·拉比泽
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2021-05-07
Filing date: 2022-05-04
Publication date: 2023-12-22
Also published as: EP4333669A1; WO2022233921A1; KR20240004973A; JP2024516862A; FR3122556A1; FR3122556B1

Abstract

A device (1) for shaping hair, comprising: -two arms (3, 4) movable relative to each other and capable of assuming a spaced apart configuration for introducing hair strands and a moved together configuration for treating hair strands, the arms (3, 4) being movable along the hair strands when in the moved together configuration; -two contact surfaces (5, 6) carried by the two arms (3, 4), respectively, arranged facing each other, at least one of the contact surfaces (5, 6) being a heating surface, -at least one strip (12, 12a,12b,12c,12 d) made of a friction material comprising a silicone elastomer, a fluoroelastomer or a perfluoroelastomer, attached to each contact surface (5, 6) such that a height (H) strictly greater than 0mm and less than 2mm protrudes from the contact surface (5; 6) to which it is attached, even in the configuration in which the arms (3, 4) are moved together, the height (H) is strictly greater than 0mm.

Description

Device for shaping hair

Technical Field

The present invention relates to a device for shaping hair, in particular for a hair relaxing and/or straightening operation.

Background

Many devices for shaping hair are known, in particular hair straightening irons, jigs or hair straighteners, for example as described in US 2009/044823.

Typically, hair straighteners are constituted by two arms connected together by means of a hinge enabling opening and closing of the arms, and a heating device comprising at least one heating element arranged on the arms. During the operation of treating the hair tress, the hair tress is introduced between the two arms in the open position, and then the two arms are manually closed on the hair tress. The lock is then subjected to the heat emitted by the heating element until the two arms are opened and the lock is removed.

For better shaping results, the heating element may be combined with at least one comb, which may or may not be a heating comb, which allows strands of hair to separate as they pass between the arms and friction to be applied in order to produce a more uniform result. For example, in application FR2940894 a device of this type is described, comprising a friction bar movably mounted with respect to the straightening surface and capable of interacting with the opposite friction bar when the arm is in the closed position, so as to define a pulling force zone which generates a pulling force greater than the pulling force generated by the treatment zone when the device is moved over the hair tresses.

WO2017/089152 discloses a device for shaping hair comprising a heating plate for heating hair, a temperature sensor and a thermal control circuit, the surface of the heating plate possibly comprising silicone strips. Similar devices are described in CN207152182 and CN 207270050.

The known device is not entirely satisfactory when sufficient friction is to be obtained between the lock of hair and the heating means during shaping, which results in a lack of alignment of the hair.

Thus, there is a need for a hair shaping device that allows better shaping, in particular more efficient and uniform straightening.

Disclosure of Invention

The object of the present invention is fully or partly achieved by a device for shaping hair, comprising:

two arms movable relative to each other and capable of assuming a spaced apart configuration for introducing hair tresses therebetween and a moved together configuration for treating the hair tresses, the two arms being movable along the hair tresses when in the moved together configuration,

two contact surfaces carried by the two arms, respectively, the two contact surfaces being arranged to face each other, at least one of the two contact surfaces being a heating surface,

-at least one strip made of a friction material comprising a silicone elastomer, a fluoroelastomer or a perfluoroelastomer, said at least one strip being attached to each of said contact surfaces such that it protrudes from the contact surface to which it is attached by a height strictly greater than 0mm and less than 2mm, said height being strictly greater than 0mm even in the form of the two arms moving together, said at least one strip attached to one of said two contact surfaces being arranged such that it is offset with respect to said at least one strip attached to the other of said two contact surfaces in the form of the two arms moving together.

By the present invention, with increasing friction generated by each strip, movement of the device relative to the hair tresses can be slowed down, which allows a more uniform and efficient hair straightening to be obtained.

The term "hair" includes keratin fibres of a human or corresponding animal, but preferably human, as well as synthetic fibres, known as "extensions", which are sometimes added to the natural hair of an individual by various means, in particular by adhesive bonding, in order to change the appearance of the natural hair of an individual as well as synthetic or non-synthetic fibre hairpieces, for example.

By "contact surface" is meant a surface for treating hair, preferably a straightening surface, e.g. a straightening surface formed by a straightening plate, which is advantageously a heating plate, as will be described below. Each treatment surface is for contact with at least one lock of hair during hair treatment. The contact surfaces are preferably planar and arranged parallel to each other in the moved together configuration. The contact surface may be made of an inorganic material, such as a metal or a ceramic, such as anodized aluminum or aluminum with a ceramic surface treatment.

The at least one strap is preferably not movable relative to the contact surface to which it is attached. It should be noted that it has a certain elasticity, depending on the friction material used. It preferably has a continuous and flat friction surface, in particular a friction surface without irregularities, for example without teeth.

The height of the at least one strip projection when in the spaced apart configuration of the arms is preferably between 0.5mm and 2mm, preferably substantially equal to 1mm.

The silicone elastomer may or may not be fluorinated. In particular, the silicone elastomer is selected from the group consisting of vinyl methyl silicone (VMQ), polyvinyl methyl silicone (PVMQ), fluorovinyl methyl silicone (FVMQ) and methyl silicone (MQ), preferably vinyl methyl silicone (VMQ).

Fluoroelastomers (FKM) are known, for example, by the name of Chemours companyBy Solvay under the nameAnd by DuPont under the name +.>And (5) selling series products. Perfluoro (C)The elastomer (FFKM) belongs, for example, to the name +.>And->And (5) selling series products.

These materials (silicone elastomers, fluoroelastomers, and perfluoroelastomers) that can form friction materials are elastic. They can also withstand continuous use at temperatures greater than 230 ℃.

The at least one strip is preferably free of any material other than friction material. In particular, the at least one strip may be entirely composed of synthetic polymers, free of any mineral elements or multi-mineral elements or infrared powders.

The friction material preferably has a Shore a (Shore a) hardness of between 40Shore a and 90Shore a, in particular substantially equal to 70Shore a.

In the moved-together configuration, the clamping force of the arms (i.e. when the device is used to apply a clamping force to the hair tresses which are engaged between the arms in the moved-together configuration) may be between 10N and 30N, for example equal to 10N, 20N or 30N. The tension of the hair lock may be between 9.5N and 12.5N for a clamping force of 30N and a temperature of the at least one surface equal to 200 ℃. The speed of the hair tresses through the device is preferably about 1.8cm/s.

The width of the at least one strip may be between 0.5mm and 10mm, in particular between 1mm and 5mm, preferably between 1mm and 2mm, preferably substantially equal to 1.9mm.

The at least one strip may take any shape, for example sinusoidal. As a variant, the at least one strip has a friction surface with a rectilinear longitudinal axis, in particular a rectangular shape, the friction surface preferably extending longitudinally along an axis parallel to the longitudinal axis of the contact surface to which it is attached.

The friction surface of the at least one strip advantageously covers an area of less than 50%, preferably less than 40%, more preferably less than 20% of the surface area of the contact surface to which it is attached.

In a particular embodiment, one of the two contact surfaces comprises a single strip and the other of the two contact surfaces comprises two strips arranged to lie on either side of the single strip in the moved together configuration of the arms.

In this case, a single strip may be arranged equidistant from the side edges of the contact surface to which it is attached, and two strips are attached at the same distance as the side edges of the contact surface to which they are attached, respectively.

In another embodiment, each contact surface comprises two strips.

When at least one of the contact surfaces comprises two strips, these strips advantageously extend parallel to each other.

The at least one strap may extend in a height direction along an axis perpendicular to the contact surface to which it is attached.

The at least one strip may take the shape of a parallelepiped of substantially square or rectangular cross-section.

As a variant, the at least one strip has a substantially trapezoidal cross section, the width of the friction surface of the at least one strip for contact with the hair strand being smaller than the width of the surface opposite thereto.

In this case, the edges of the at least one strip each form an angle with the friction surface of between 5 ° and 30 °, preferably between 10 ° and 20 °, the angle formed between one of the edges and the friction surface of the at least one strip preferably being equal to the angle formed between the other of the edges and the friction surface of the at least one strip.

In a particular embodiment, each contact surface may comprise at least one recess for receiving the at least one strap. In this case, the at least one groove may have a substantially trapezoidal cross section, the width of which decreases from the bottom toward the opening of the groove. The profile of the portion of the strip that is received in the recess may be designed to conform to the shape of the recess. The strip may be slid into the groove or press-fit into the groove.

In another embodiment, the at least one strap is attached to the contact surface as an overthickness, in which case the contact surface may be free of any relief for accommodating the at least one strap. In this case, it is conceivable to carry out the surface treatment with a thin layer of deposited friction material to produce such a strip.

In this case, the at least one strip may be attached to the contact surface by means of an adhesive friction material or by means of a coating process. "coating process" refers to a process that includes spraying a deposit in a non-polymeric form onto a contact surface and then heating or irradiating the deposit to polymerize it into a friction material to adhere it to the contact surface.

The apparatus is preferably a straightening iron.

The apparatus preferably comprises heating means for heating said at least one contact surface, which is a heating surface. The total heating power of the device may be between 50W and 200W.

The device may comprise steam emitting means, which may be used in particular when passing hair strands between contact surfaces.

The device may comprise one or more combs, which may be detachable or non-detachable.

According to another aspect of the invention, another subject of the invention is a method for treating hair using the device defined above, comprising the steps of: the hair tresses are introduced between the arms in a spaced apart configuration, a clamping force is applied to the arms such that they transition to a configuration in which they move together while clamping the hair tresses and applying the clamping force, and the device is then moved relative to the hair tresses, preferably in a direction from the root to the tip of the hair. The method may comprise repeating the above steps until the hair or a portion thereof has been treated.

The treatment process is preferably carried out under conditions in which the temperature of the at least one contact surface, which is a heated surface, is between 120 ℃ and 235 ℃, better still between 150 ℃ and 230 ℃.

When gripping hair tresses, the gripping force of the arms in the moved-together configuration may be between 10N and 30N, for example equal to 10N, 20N or 30N. The temperature of the at least one heated contact surface for a clamping force of 30N is equal to 200 ℃, and the tension of the hair tresses may be between 9.5N and 12.5N. The speed of the hair tresses through the device is preferably about 1.8cm/s.

The treatment process may be carried out with or without the use of at least one cosmetic composition, which may be applied before, during or after hair shaping, but is preferably applied before hair shaping. The treatment advantageously consists in straightening the hair.

The treatment process may also be carried out in the presence of steam, e.g. originating from the apparatus.

Drawings

The invention will be more clearly understood from a reading of the following detailed description of non-limiting embodiments thereof, and from a review of the accompanying drawings, in which:

figure 1 schematically shows in perspective view one example of an apparatus for shaping hair according to the invention,

figure 2 schematically shows the device of figure 1 in a perspective view,

fig. 3 schematically shows a view of the device of fig. 1 from below, in perspective, with one arm in partial cross-section,

figure 4 is a schematic partial cross-sectional view of the apparatus of figure 1,

figure 5 is a schematic perspective view of the apparatus of figure 1,

fig. 6 shows the same perspective view as fig. 5, with parts cut away,

fig. 7 shows the same perspective as fig. 5, with a further partial section in relation to fig. 6,

figure 8 schematically shows the heating means for the apparatus of figure 1 in isolation in a perspective view,

figure 9 shows the device of figure 1 in longitudinal section,

fig. 10 schematically illustrates the apparatus of fig. 1 in perspective view, with the arms in a moved together configuration,

figure 11 schematically shows a front view of the device of figure 1 in the configuration of figure 10,

figure 12 schematically shows a view of the device of figure 11 in cross-section,

FIG. 13 schematically shows a front view of two contact surfaces of another example of a device according to the invention, alone, and

fig. 14 schematically shows in a sectional view a further example of a strip that may be used in the device according to the invention.

Detailed Description

In the rest of the description, elements that are identical or have identical functions have identical reference numerals. For the sake of brevity of this description, they are not described with respect to each drawing, only the differences between the embodiments are described.

An example hand piece 2 of a device 1 for shaping hair is shown in fig. 1 to 12.

The handpiece 2 has two arms 3 and 4, which arms 3 and 4 are movable relative to each other between a spaced apart configuration visible in fig. 1 for introducing hair strands therebetween and a moved together configuration shown in fig. 10 to 12 for treating hair strands.

In this example, arm 3 forms an upper arm and arm 4 forms a lower arm. They are connected to each other at one end by a joint 8, the hand piece 2 thus forming a clamp.

The arms 3 and 4 define respective handle halves 10 and 11, and a user can press on the handle halves 10 and 11 to move the arms 3 and 4 together, changing them from a spaced apart configuration to a moved together configuration.

Preferably, a resilient return member (not visible), such as a spring disposed about the pin of the joint 8, is provided to return the arms 3 and 4 to the spaced apart configuration.

The invention is not limited to one particular way of connecting the arms 3 and 4 together. They may be made movable in another way without departing from the scope of the invention. However, the presence of a linker is highly preferred for the ergonomics it provides.

The arms 3 and 4 have contact surfaces 5 and 6, respectively, at the ends opposite the joint 8. The contact surfaces 5 and 6 face each other, being arranged opposite each other. At least one of the contact surfaces, in the example shown both contact surfaces 5 and 6, is a heating surface. The contact surfaces 5 and 6 form the outer surfaces of two plates 7 and 9, respectively, which plates 7 and 9 are substantially rectangular in shape, as will be described further below.

Arms 3 and 4 extend along respective longitudinal axes X and Y. The contact surfaces 5 and 6 are rectangular in shape elongated along these same respective longitudinal axes X and Y.

The arms 3 and 4 define with contact surfaces 5 and 6 therebetween an area for treating hair, said area being intended to receive a hair strand to be treated, along which the handpiece 2 moves during treatment, for example in a direction from the root to the end of the hair.

In the example in question, the handpiece 2 is configured to heat treat hair by contact with two heated contact surfaces 5 and 6.

The direction of movement of the handpiece 2 over the hair is preferably substantially perpendicular to the arms 3 and 4.

The handpiece 2 may be connected on the side of the joint 8 by a wire (not visible in the example in question) to a base station (not shown) fixed during the treatment and connected to a power supply, or may be directly connected to the power supply.

The base station provides power to the handpiece 2 and may also perform the additional function of processing the electrical signals received from the handpiece 2. Thus, the wires connecting the handpiece 2 to the base station may comprise various electrical conductors.

A user interface (not shown) may be present on the handpiece 2 to allow a user to, for example, activate or deactivate certain components of the handpiece 2.

According to the invention, at least one strip 12 made of friction material is attached to each of the contact surfaces 5 and 6 so as to protrude from the contact surface 5 or 6 to which it is attached by a height H (also visible in fig. 4 and 11), which is strictly greater than 0mm and less than 2mm, even when the arms 3 and 4 are in the form of moving together (as can be seen in particular in fig. 11 and 12). When the arms 3 and 4 are in the moved together configuration, the at least one strap 12 attached to one of the contact surfaces 5 or 6 is arranged offset relative to the at least one strap 12 attached to the other of the contact surfaces 6 or 5, as can be seen in particular in fig. 11 and 12. In the example in question, the contact surface 5 comprises a single strip 12a (visible in particular in fig. 2), while the contact surface 6 comprises two strips 12b and 12c (visible in particular in fig. 1 and 12), which strips 12b and 12c are arranged on both sides of the strip 12a when the arms 3 and 4 are in the position of being moved together. The strips 12b and 12c are arranged close to the side edges 13 of the contact surface 6 at the same distance from the side edges 13. The strip 12a is arranged at the center of the contact surface 5.

In the example shown, the friction material forming the strips 12 is a silicone elastomer, in this case vinyl methyl silicone (abbreviated VMQ). The friction material has a Shore a hardness of 70Shore a.

The presence of these strips 12 on the contact surfaces 5 and 6 makes it possible to slow down the movement and obtain better shaping, in particular straightening, results when the handpiece 2 is moved with respect to the hair tresses.

In this embodiment, the width of the strip 12 is the same for the three strips 12a,12b and 12c, and in this example is equal to 1.88mm.

The contact surfaces 5 and 6 are made of a metallic or ceramic material, in this example anodized aluminum, in the shape of a rectangle elongated along the longitudinal axis of the arms 3 and 4, respectively. In the example shown, each strip 12 extends along an axis parallel to the longitudinal axis of the arm 3 or 4. Each strip 12 has a friction surface 23, the friction surface 23 having a linear longitudinal axis, in this case rectangular, extending the entire length of the contact surface 5 or 6 to which it is attached. In the example shown, the contact surfaces 5 and 6 are planar shapes surrounding one or more strips 12.

However, each contact surface 5 or 6 comprises one or two grooves 14 extending longitudinally from one longitudinal edge 15 to the other longitudinal edge 16 of the contact surface 5 or 6. Each groove 14 forms a recess and is adapted to receive a strap 12. The number of grooves 14 in the contact surface is equal to the number of strips present on the contact surface, preferably one or two per contact surface.

In the example shown, the recess 14 has a substantially trapezoidal cross section, the width of which decreases from the bottom 29 of the recess 14 in the direction of the opening 17 of the recess 14, as can be seen more clearly in fig. 4.

Each strip 12 is substantially trapezoidal in shape and/or conforms to the substantially trapezoidal shape of the recess 14 in which it is received, as explained above, by a height H from the opening 17 of the recess relative to the respective contact surface 5 or 6.

In this example, the side edges 21 and 22 of the strip 12 each form an angle α and β with the friction surface 23 of the strip of between 10 ° and 20 °, which angles α and β are equal to each other in the example shown. In this example, the trapezoid within which the substantially trapezoidal shape of each strip 12 inscribes is an isosceles trapezoid.

The corners of the generally trapezoidal shape formed by the strips 12 are slightly rounded, in this example in a more pronounced manner on the side of the bottom 29 of the groove 14.

The width of the friction surface 23 of the strip is smaller than the width of the opposing surface 24 in contact with the bottom 29 of the groove 14.

Each strip 12 extends in the height direction along an axis Z perpendicular to the contact surface 5 or 6 to which it is attached, for example as shown in fig. 4.

In the example shown still, the friction surface 23 of the or each strip 12 occupies less than 20% of the surface area of the contact surface 5 or 6 to which it is attached. In other words, each strip 12 should not occupy an area greater than 20% of the surface area of the contact surface 5 or 6. For example, if there are two strips 12 on one contact surface, the total area occupied by the two strips 12 cannot be greater than 40% of the total area of the contact surface.

In this example, the strips 12b and 12c are parallel to each other.

The strip 12 extends in a height direction perpendicular to the longitudinal axis X or Y of the arm 3 or 4, which corresponds to the longitudinal axis of the contact surface 5 or 6, respectively.

In contact with the hair is the friction surface 23 of the strip 12. When the hair tresses pass through, the arms 3 and 4 are in the moved-together configuration, the strip 12 may be squeezed to a degree so as to reduce the height H, whereas when the arms 3 and 4 are in the moved-together configuration, the height H remains strictly greater than 0mm, preferably greater than 0.5mm.

In the example shown, the contact surface 6 forms the outer surface of the plate 9, in this example the plate 9 forms the heating means 25 of the device, as more clearly seen in fig. 4, 6 and 7, the heating means 25 comprising a compartment 26 housing a heating element 27, the heating element 27 being electrically connected to a base station or a power supply via the wires mentioned hereinabove using wires (not visible). In this example, both the compartment 26 and the heating element 27 are parallelepiped in shape and extend parallel to the contact surface 6 as can be seen.

As can be seen in fig. 4, the shape of the heating means 25 allows the introduction of the recess 14, as well as the side edges 13 of the contact surface 6 and the through holes 28, the contact surface 6 being largely rectilinear but rounded away from the contact surface 6, the through holes 28 being located on both sides of the compartment 26. The through holes 28 may be replaced with solid material without departing from the scope of the present invention.

In the example shown, the contact surface 5 forms the outer surface of the plate 7, in this example the plate 7 forms a heating device 30, which heating device 30 comprises a compartment 31 housing a heating element 32, which heating element 32 is electrically connected to a base station or a power supply via the above-mentioned lines using an electrical wire 33 (visible in fig. 8), similar to the heating device 25. In this example, both the compartment 31 and the heating element 32 are parallelepiped in shape and extend parallel to the contact surface 5 as can be seen. As shown in fig. 8, the shape of the heating means 30 allows the introduction of the recess 14, as well as the side edges 13 of the contact surface 5 and the through holes 34, the contact surface 5 being largely rectilinear but rounded away from the contact surface 5, the through holes 34 being located on both sides of the compartment 31. The through holes 34 may be replaced with solid material without departing from the scope of the present invention.

During use, a lock of hair is introduced between the arms 3 and 4 in a spaced apart configuration, and a clamping force is applied to the arms 3 and 4 by the half handles 10 and 11, so as to move the arms 3 and 4 to a configuration in which they are moved together while clamping the lock of hair, the clamping force being between 10N and 30N, for example 30N. Next, the device 1 is moved relative to the hair tresses, preferably in a direction from the root to the tip of the hair. Needless to say, these steps may be repeated for other hair locks until the hair or a portion thereof has been treated.

The temperature of the heated contact surfaces 5 and 6 is for example equal to 200 deg.c.

For a clamping force of 30N, the pull of the hair lock is between 9.5N and 12.5N in the presence of the strip 12. The temperature of the at least one contact surface is equal to 200 ℃. The speed of the hair tresses through the device is about 1.8cm/s. For a treated hair length of 27cm, the speed of movement will be about 15s.

Needless to say, the present invention is not limited to the example just described.

In the embodiment of fig. 13, each contact surface 5 and 6 comprises two strips 12 arranged such that when the arms 3 and 4 are in a moved together configuration, the two strips 12 attached to the contact surface 5 do not overlap onto the strips 12 attached to the contact surface 6. In this example, the distance from one strip 12 to the nearest side edge 13 of the contact surface is different from the distance from the other strip 12 to the nearest side edge 13 of the contact surface, both for the contact surface 5 and for the contact surface 6. In other words, for a given contact surface, the strips 12 are not disposed equidistant from the nearest side edge 13 of that contact surface.

One or more of the strips 12 may take on different shapes, such as a sinusoidal shape, without departing from the scope of the present invention.

The cross-section of the strip 12 may take a rectangular shape, for example, as shown in fig. 14.

The device may be designed to apply steam and/or cosmetics to hair.

The friction material may be a fluoroelastomer or a perfluoroelastomer.

The presence of strips 12 made of silicone elastomer, fluoroelastomer or perfluoroelastomer friction material of the device according to the invention makes it possible to obtain a satisfactory hair alignment, a smooth hair appearance in terms of the ends and lengths sought, and a desired hair manageability and smooth feel.

Claims

1. A device (1) for shaping hair, comprising:

-two arms (3, 4), said two arms (3, 4) being movable relative to each other and being capable of assuming a spaced apart configuration for introducing hair locks between said two arms (3, 4) and a moved together configuration for handling said hair locks, said two arms (3, 4) being capable of moving along said hair locks when in said moved together configuration,

-two contact surfaces (5, 6) carried by the two arms (3, 4), respectively, the two contact surfaces (5, 6) being arranged facing each other, at least one of the two contact surfaces (5, 6) being a heating surface,

at least one strip (12, 12a,12b,12c,12 d), said at least one strip (12, 12a,12b,12c,12 d) being made of a friction material comprising a silicone elastomer, a fluoroelastomer or a perfluoroelastomer and being attached to each of said two contact surfaces (5, 6) such that a height (H) protrudes from said contact surface (5; 6) to which it is attached, said height (H) being strictly greater than 0mm and less than 2mm, even in the configuration in which said two arms (3, 4) are moved together,

one (5; 6) of said two contact surfaces comprising a single strip (12, 12 a),

the other (6; 5) of said two contact surfaces comprises two strips (12, 12b,

12c) The two strips (12, 12b,12 c) are arranged so as to be located on both sides of the single strip (12, 12 a) in the form of the two arms (3, 4) moving together.

2. The device (1) according to claim 1, in the spaced apart configuration of the two arms (3, 4), the height (H) at which the at least one strip (12, 12a,12b,12c,12 d) protrudes being between 0.5mm and 2mm, preferably substantially equal to 1mm.

3. Device (1) according to claim 1 or 2, the silicone elastomer being selected from the group consisting of Vinylmethylsilicone (VMQ), polyvinylmethylsilicone (PVMQ), fluorovinylmethylsilicone (FVMQ) and Methylsilicone (MQ), preferably Vinylmethylsilicone (VMQ).

4. The device (1) according to any one of the preceding claims, wherein the width of the at least one strip (12, 12a,12b,12c,12 d) is between 0.5mm and 10mm, in particular between 1mm and 5mm.

5. Device (1) according to the preceding claim, wherein the width of the at least one strip (12, 12a,12b,12c,12 d) is between 1mm and 2mm, preferably substantially equal to 1.9mm.

6. The device (1) according to any one of the preceding claims, wherein the friction material has a Shore a hardness of between 40Shore a and 90Shore a, in particular substantially equal to 70Shore a.

7. The device (1) according to any one of the preceding claims, wherein the at least one strip (12, 12a,12b,12c,12 d) has a friction surface (23), the friction surface (23) having a linear longitudinal axis, in particular the friction surface (23) being rectangular in shape, the friction surface (23) extending longitudinally along an axis parallel to the longitudinal axis (X; Y) of the contact surface (5; 6) to which it is attached.

8. Device (1) according to any one of the preceding claims, wherein the friction surface (23) of the at least one strip (12, 12a,12b,12c,12 d) covers an area of less than 50% of the surface area of the contact surface (5; 6) to which it is attached, preferably less than 40% of the surface area of the contact surface (5; 6) to which it is attached, more preferably less than 20% of the surface area of the contact surface (5; 6) to which it is attached.

9. The device (1) according to any one of the preceding claims, wherein the single strip (12, 12 a) is arranged equidistant from the side edges (13) of the contact surface (5) to which it is attached, and the two strips (12, 12b,12 c) are attached at the same distance as the side edges (13) of the contact surface (6) to which they are attached, respectively.

10. The device (1) according to any one of the preceding claims, wherein said at least one strip (12, 12a,12b,12c,12 d) has a substantially trapezoidal cross section, the width of the friction surface (23) of said at least one strip (12, 12a,12b,12c,12 d) for contact with said hair strand being smaller than the width of the surface opposite to said friction surface (23).

11. The device (1) according to the preceding claim, wherein edges (21, 22) of the at least one strip (12, 12a,12b,12c,12 d) each form an angle (α, β) with the friction surface (23) of between 5 ° and 30 °, preferably between 10 ° and 20 °, preferably an angle (α) between one of the edges (21) and the friction surface (23) of the at least one strip (12, 12a,12b,12c,12 d) is equal to an angle (β) between the other of the edges (22) and the friction surface (23) of the at least one strip (12, 12a,12b,12c,12 d).

12. The device (1) according to any one of the preceding claims, wherein each contact surface (5, 6) comprises at least one groove (14) for receiving the at least one strip (12, 12a,12b,12c,12 d), the at least one groove (14) preferably having a substantially trapezoidal cross section, the width of which decreases from a bottom (29) towards an opening (17) of the groove (14).

13. A method for treating hair using a device (1) according to any of the preceding claims, the method comprising the steps of:

-introducing the hair lock between two arms (3, 4) in a spaced apart configuration,

-applying a closing force to the two arms (3, 4) so that they transition to a configuration of moving together, simultaneously pinching the lock of hair and applying a pinching force, and then

-moving the device with respect to the lock of hair, preferably in a direction from the root of the hair towards the end of the hair.