EP2575529B1

EP2575529B1 - Device for confinement of a cosmetic product on a volume of keratin fibers, kit and associated method

Info

Publication number: EP2575529B1
Application number: EP11722445.1A
Authority: EP
Inventors: Anne Debauge; Christian Revenu; Thomas Rivet
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2010-06-03
Filing date: 2011-05-31
Publication date: 2014-12-24
Anticipated expiration: 2031-05-31
Also published as: JP2016120330A; KR20130122604A; JP2013534838A; FR2960748A1; CN103037730B; WO2011151310A1; JP6276312B2; CN103037730A; FR2960748B1; ES2533126T3; BR112012030775A2; EP2575529A1

Description

This invention relates to a device according to the preamble of claims 1.
In particular for the meaning of this invention, "cosmetic product" means a product as defined in Directive 93/35 EEC of the Council dated June 14, 1993.
The cosmetic product is advantageously a composition for the permanent deformation of keratin fibers and particularly hair, such as a reducing composition for hair perming.
The most usual technique for obtaining a permanent hair deformation is to apply a composition containing an appropriate reducing agent and then, after rinsing the hair thus treated, applying an oxidizing composition to the hair previously tensioned for example using curlers, to finally give the required shape to the hair.
This technique can create wavy hair using a permanent hair wave method.
The new shape imposed on the hair by a chemical treatment like that described above is durable and in particular resists the action of washing with water or shampoo, unlike simple classical temporary deformation techniques such as hairsetting.
Once the curler has been put into place on the hair, devices of the above-mentioned type which are applied to the curler to cover the hair during application of the perming product are known for example from FR 1 430 896 , US 2 299 367 and GB 743 128 .
Such devices are not fully satisfactory. These devices have a wide opening to the outside such that part of the cosmetic product can escape, thus reducing the efficiency of the perming method.
Therefore, a higher dose of the reducing composition has to be applied to the hair to obtain the required effect, which can be unpleasant for the user.
EP-A-1 920 674 discloses an application tool comprising two plates connected together.
US-A-2008/087293 discloses a hair treatment application system comprising the combination of at least one absorbent substrate having specific median pore radius of from about 300 microns to about 3,000 microns and of one or more hair treatment composition, each having a viscosity of from about 3,00 cPs to about 150,000 cPs.
EP-A-1 275 320 discloses an applicator consisting of an implement with two articulated branches.
DE-A-200 16 344 discloses a coating device for applying a liquid on hair that is wound onto a curler.
One object of the invention is to obtain a device to extremely efficiently apply and confine a cosmetic product on a volume of keratin fibers such as a hair lock, in order to increase the efficiency of the cosmetic treatment resulting from the product.
Another object of the invention is to obtain a device to perform a particularly efficient cosmetic treatment using smaller quantities of product to reduce the treatment cost.
Another object of the invention is to obtain a very easily handled confinement device to simplify use of the cosmetic treatment.
Consequently, the subject-matter of the invention is a device according to claim 1.
The device according to the invention may comprise one or several of the features of claims 2 to 10, taken in isolation or in any technically possible combination.
Another subject-matter of the invention is a method according to claim 11.
The treatment method according to the invention may comprise the features of claim 12.
The invention will be better understood after reading the following description given solely as an example with reference to the appended drawings, in which:

figure 1 is a top view of a first treatment kit according to the invention, the hair tensioning assembly being arranged outside the confinement device;
figure 2 is a side view of the kit in figure 1, the hair tensioning assembly being placed in the confinement device;
figure 3 is a sectional view of the kit in figure 2 along a median transverse plane;
figure 4 is a sectional view of a deformable portion of the confinement device along a median transverse plane;
figure 5 is a perspective view of the deformable portion shown in figure 4;
figure 6 is a perspective three-quarters front view of the kit in figure 2;
figure 7 is a side view of a second kit according to the invention;
figure 8 is a top view of the kit in figure 7;
figure 9 is a diagrammatic view of a detail of the attachment means of the confinement device in figure 7;
figures 10 and 11 are variants of the seal for the confinement devices according to the invention;
figure 12 is a view similar to figure 3 of a third kit according to the invention;
figure 13 is a top view of a fourth kit according to the invention;
figure 14 is a side view of the confinement device shown in figure 13;
figure 15 is a sectional view along a median transverse plane of the confinement device in figure 13; and
figure 16 is a perspective three-quarters front view of a deformable portion of the device in figure 13.

Figures 1 to 6 show a first cosmetic treatment kit 10 according to the invention.
This first kit 10 is intended to be used to treat in particular a group of keratin fibers 11 of a user, visible in figures 2 and 3, and particularly a lock of hair.
Treatment is done by the application of a cosmetic product onto the lock of hair, and by confinement of the cosmetic product on the lock, possibly with heating, using the kit 10 according to the invention.
Hair treatment includes care or conditioning of hair, holding or setting or perming of the hair, temporary, semi-permanent or permanent hair coloring, straightening or smoothing.
According to one particular example, the product is a permanent hair deformation composition.
For example, the cosmetic product may be a reducing cosmetic composition that is intended to reduce keratin disulfide bonds.
As shown in figure 1, the kit 10 comprises a keratin fiber tensioning assembly 12 and a confinement device 14 according to the invention.
The tensioning assembly 12 comprises a tensioning part 16 and advantageously heating means 18 and a part 20 for electrical connection of the heating means 18.
The tensioning part 16 is generally elongated in shape along a longitudinal axis A-A'.
This part 16 may for example be cylindrical and forms a roller or a rod forming a curler.
In this example, the heating means 18 are fixed to the tensioning part 16. They are advantageously arranged in a cavity formed in this part.
In one variant (not shown), the heating means are carried by the confinement device 14.
In the example shown in figures 1 and 6, the connection part 20 comprises an electrical wire 22 that is intended to be connected to a source of electrical current, and a connection head 24 that is intended to be plugged into the heating means 18 and which can be removed.
In this example, the head 24 can be removed from the heating means 18 and the tensioning part 16.
As a variant, the electrical wire 22 is permanently connected to the heating means 18.
For example, the electrical connection head 24 is plugged into one longitudinal end of the tensioning part 16.
The tensioning part 16 comprises an outer surface 21 that shapes the keratin fibers onto which the keratin fibers 11 are to be applied. When the keratin fibers 11 are wound onto the tensioning part, the part 16 defines a volume of fibers 11.
As shown in Figure 5, the confinement device 14 comprises two elements 28A, 28B free to move relative to each other to form a clip, the two elements 28A, 28B being maneuverable between an open position in which the keratin fibers can be put into place and a closed position in which the volume of keratin fibers can be confined.
Each mobile element 28A, 28B comprises a rigid portion 30A, 30B forming a support and a deformable portion 32A, 32B formed by a flexible half-shell to contain and confine the volume of keratin fibers.
In the example shown in figures 1 to 6, the device 14 also comprises means 36 of hinging the mobile elements 28A, 28B to each other.
Each rigid portion 30A, 30B comprises a maneuver region 38 and a support region 40, the maneuver region 38 and the support region 40 being located on each side of the articulation means 36.
The support regions 40 of the respective rigid portions 30A, 30B are located facing each other and at a distance from each other.
Each maneuver region 38 in this example comprises a lug 42 projecting transversely away from the support region 40.
In this example, the support region 40 and the maneuver region 38 are made in a single-piece from the same material.
The support region 40 comprises a opened frame 44 delimiting a central opening 46. As shown in figure 1, the frame 44 is substantially elongated along an axis B-B'.
The contour of the central opening 46 is designed to contain the tensioning part 16 and surround it around its periphery.
In the example shown in figure 1, the frame 44 extends substantially in a plane. It is advantageously substantially rectangular in shape. It comprises two longitudinal uprights 48A, 48B substantially parallel to the axis B-B' connected to each other at their ends through transverse cross-pieces 50A, 50B.
The maneuver region 38 projects from an upright 48B in the support region 40. In the example shown in figure 1, the length of the cross-pieces 50A, 50B perpendicular to line B-B' is less than the length of the uprights 48A, 48B taken parallel to axis B-B'.
A first cross-piece 50A extends substantially in the plane of the frame 44. A second cross-piece 50B also comprises a convex central region 52 delimiting a notch 54 opening up facing the opposite rigid portion 30A, 30B.
The articulation means 36 comprise articulation tabs 60A, 60B fixed to the first rigid portion 30A and the second rigid portion 30B respectively, an articulation axis 62 connecting the tabs 60 to each other, and an elastic actuation part 64 bringing the elements 28A, 28B into the closed position.
The tabs 60A, 60B project towards each other from each region 38 maneuvering a rigid portion 30A, 30B. They are advantageously made of the same material as the maneuver regions 38.
The hinging axis crosses the tabs 60A, 60B and connects them to each other. It extends substantially parallel to axis B-B' that extends from the support region 40.
Thus, the rigid portions 30A, 30B can be moved relative to each other to move the confinement device 14 from the open position in which the support regions 40 are at a distance from each other and the maneuver regions 38 are close to each other, and the closed position in which the support regions 40 are close to each other and the maneuver regions 38 are at a distance from each other.
The elastic actuation part 64 may for example be formed of a spring capable of actuating the rigid portions 30A, 30B to bring them into the closed position of the device 14.
In this example, the actuation part 64 is formed from a spring added on between the maneuver regions 38.
As a variant (not shown), the actuation part 64 is formed by elastic strips made from the same material as at least one of the maneuver regions 38.
The deformable portions 32A, 32B in this example are formed by flexible half- shells 70A, 70B delimiting an intermediate confinement space 72 of the volume of keratin fibers 11, when the device 14 is in the closed position.
In the example shown in figures 4 and 5, each half shell 70A, 70B comprises a peripheral seal 74 and a central wall 76 that will be applied to the volume of keratin fibers 11 to match its shape.
The peripheral seal 74 is complementary in shape to the frame 44 on which it is fixed. It comprises a solid bead 78 defining an attachment surface 80 on the frame 44 and an opposite surface 82 applied onto the seal 74 of the opposite half- shell 70B, 70A. The peripheral seal 74 also advantageously comprises a rib 83 that projects upwards from the surface 80 to be inserted in a corresponding groove (not shown) formed in the frame 44.
The application surface 82 is substantially plane so that a seal will be formed when it is applied to the application surface 82 of the facing half shell 70B, 70A.
The peripheral seal 74 comprises two longitudinal regions 84A, 84B applied to the uprights 48A, 48B of the frame 44 and two transverse regions 86A, 86B applied on the corresponding cross-pieces 50A, 50B.
In the closed position, a first transverse region 86A of a half shell 70A, 70B extends substantially in a plane so that it can be applied over its entire length onto the corresponding region 86A of the opposite half- shell 70B, 70A. A second transverse region 86B comprises a convex central portion that fits into the notch 54 defining a recess 90 into which the electrical connection head 24 of the tensioning assembly 12 will fit in a complementary manner.
The peripheral seal 74 delimits a central opening 92 that is completely closed off by the deformable wall 76.
The deformable wall 76 is formed from a thin extendable film. "Extendable film" means a film that can be elastically and reversibly deformed to increase its total area, for example by reducing its thickness.
The film forming the wall 76 is thinner than the bead 78 forming the seal 74, and is advantageously half its thickness.
The film is made from a material that can be elastically and reversibly extended, without any significant plastic strain.
Thus, the surface area of the wall 76 can increase by at least 10%, for example between 10% and 100% without any significant plastic strain, to match the shape of the volume of keratin fibers 11 arranged in the intermediate space 72.
The film of the extendable wall 76 is advantageously made from a deformable polymer such as silicone or an elastomer like natural rubber, an EPDM (ethylene propylene diene copolymer), an NBR (copolymer of butadiene and acrylonitrile) or a thermoplastic, particularly a thermoplastic elastomer such as TPU, SEBS, SBS or a flexible thermoplastic such as EVA.
In the example shown in figure 5, the wall 76 is made of the same material as the peripheral seal 74. The wall 76 extends the seal 74 in the opening 92.
As shown in figure 4, when the peripheral wall 76 is in the rest position and when no external stress is applied to it, it comprises a central region 100 in the form of a cylindrical dome with longitudinal axis B-B' and advantageously two lateral gutters 102 to facilitate deformation of the central region 100.
The central region 100 projects outwards in the opening 92 delimited by the peripheral seal 74. It is convex outwards.
The gutters 102 extend on each side of the central portion 100. They are convex inwards, opposite to the convexity of the central portion 100.
Thus when at rest, the wall 76 has a substantially omega-shaped contour in section in a transverse plane relative to axis B-B'.
When the confinement device 14 moves from its open position to its closed position, the half shells 70A, 70B can move towards each other between a configuration in which they are at a distance from each other and a configuration in which one is applied to the other.
Thus in the open position of the device, the application surfaces 82 of the peripheral seals 74 are at least partially separated from each other, particularly along the two longitudinal regions 84B furthest from the articulation axis 62.
The intermediate space 72 is then open to enable insertion of the volume of keratin fibers 11 between the mobile elements 28A, 28B.
In the closed position of the device 14, the application surfaces 82 of the peripheral seals 74 are applied to each other substantially around their entire perimeter except at the recess 90, advantageously over more than 75% of their perimeter as measured around the entire periphery of the seals 74.
In this example, the seals 74 delimit a passage 104 formed by the facing recesses 92 through which the electrical connection part 20 is inserted, with a shape complementary to the shape of the external section of the head 24 of this part 20.
Thus in the closed position, the half-shells 70 are put into shape to define a substantially sealed intermediate space 72 when the volume of keratin fibers 11 is located in this space.
For the purposes of this invention, "substantially sealed" means that this space is closed off between the half- shells 70A, 70B either entirely by the facing seals 74, or partly by the facing seals 74 and partly by the tensioning assembly 20 placed in a corresponding manner in the insertion passage 104 defined between the seals 74 in the complementary portion.
"Closed" means that the gap that may be present locally between the facing seals 74 or between a seal 74 and the tensioning assembly 20 is less than 2% and advantageously less than 1% of the thickness of the seal 74.
Note that the keratin fibers 11 are partially clamped between the seals 74 around part of the periphery of the seals 74.
In this example, the seals 74 in particular close off the intermediate space 72 by being applied to each other along the longitudinal regions 84A, 84B of the seals 74 and on at least one transverse region 86A perpendicular to line B-B'.
In one variant (not shown), the seals 74 are applied to each other around the entire periphery of the intermediate space 72. In this case, they do not define an opening 104 larger than their interstice.
In the closed position, the seal is compressed by at least 1% of its height relative to its height in the open position and advantageously not more than 75% of its height relative to its height in the open position.
In the closed position, the wall 76 is deformable by an outwards movement of the gutters 102, and then by reversible elastic extension of the wall 76 to increase its surface area, as a function of the volume defined by the group of keratin fibers 11 supported on the tensioning assembly 20, or by the group of keratin fibers alone in the absence of tensioning assembly 20.
We will now describe operation of the first kit 10 according to the invention for treatment of a group of keratin fibers 11.
Initially, the confinement device 14 and the tensioning assembly 12 are supplied separately. The confinement device 14 is in its closed position in which the actuation part 64 holds the deformable half- shells 70A, 70B applied to each other with their peripheral seals 74 in contact.
The group of keratin fibers 11 to be treated is selected and is then wound around the tensioning part 16. A cosmetic product, advantageously a permanent hair wave composition like that described above, is then applied to the keratin fibers 11, for example by spraying or by using an applicator.
The electrical connection part 20 is then connected to the heating means 18 of the tensioning part 16.
The operator then grips the maneuver regions 38 of the confinement device 14 between his fingers. He brings these maneuver regions 38 towards each other against the resistance of the elastic actuation part 64, to pivot the rigid portions 30A, 30B about the axis 62 at a distance from each other.
Displacement of the rigid portions 30A, 30B causes combined displacement of the flexible half- shells 70A, 70B to move them away from each other and moves the confinement device 14 into its open position in which the volume of keratin fibers 11 is put into place.
The device 14 is then moved towards the tensioning part 16 to insert the part 16 and the keratin fibers 11 into the intermediate space between the half- shells 70A, 70B.
The operator then presses the tensioning part 16 against an extendable wall 76 of a half shell 70B by inserting it through the central opening 46 of the frame 44.
If he wishes, the operator places the electrical connection part 20 in a recess 90.
The operator then releases the maneuver regions 38. Under the effect of the actuation part 64, the maneuver regions 38 pivot from each other and the support regions 40 move towards each other to enable application of the peripheral seal 74 of one half-shell 70A onto the peripheral seal 74 of the facing half-shell 70B.
During this displacement, the keratin fibers 11 are trapped between the facing seals 74 along a longitudinal region 84B. Similarly, the electrical connection part 20 is fixed in a complementary manner in the passage 104 defined by the recesses 90.
Since the extendable wall 76 is deformable, it is firmly applied onto the volume of keratin fibers 11 defined by the fibers 11 wound onto the tensioning part 16, causing outwards deployment of the central region 100 and possibly its extension, and outwards deployment of the gutters 102.
Since the peripheral seals 74 are applied to each other around substantially their entire periphery, they clamp the connection head 24 of the electrical connection part 20 and the keratin fibers 11 passing through the seals 74, between each other. The intermediate space 72 defined between the half- shells 70A, 70B in the closed position is then closed in a substantially sealed manner around the entire periphery of this space 72.
The shape of this inner space 72 is then substantially complementary to the shape of the volume of keratin fibers 11 and the tensioning part 16, when there is one. This minimizes the volume of gas present around the keratin fibers 11 in the space 72 and thus increases the treatment efficiency.
The heating means 18 are then switched on to increase the temperature of the keratin fibers 11 to between 50 °C and 250 °C, and advantageously between 55 °C and 150 °C and more particularly between 60 °C and 90 °C.
The duration of this heating is then between one minute and two hours, preferably being one minute and 30 minutes, and even better between 5 minutes and 20 minutes and ideally between 10 minutes and 15 minutes.
Once the treatment is terminated, the operator brings the maneuver regions 38 towards each other once again opposing the resistance of the actuation part 64 to open up the confinement device 14 and extract the volume of the keratin fibers 11 from the space 72.
An oxidizing composition containing at least one oxidizing agent is then applied to fix conformation of the keratin fibers by oxidation, by reforming disulfide bonds.
Therefore, the confinement device 14 safely and simply delimits a sealed space 72 for the cosmetic product, even when the electrical connection part 20 passes through the device 14.
Due to the presence of the deformable half- shells 70A, 70B particularly comprising an extendable wall 76, the confinement device 14 is capable of being adapted to variable volumes of keratin fibers 11 which can result either from the quantity of selected fibers 11 or winding characteristics of these fibers 11 on a tensioning part 16 if any, or the shape of the tensioning part 16.
This result is obtained through a very simple, fast and reliable manipulation, using a device 14 that can be easily cleaned between two uses.
In particular, this reduces the cost of the cosmetic treatment by reducing the time necessary for preparation of this treatment.
The confinement device 14 of a second kit 150 according to the invention is shown in Figures 7 to 9.
Unlike the device 14 in the first kit 10, the rigid portions 30 are articulated to each other by articulation means 36 formed by a film hinge 152. Advantageously, the confinement device 14 does not have a maneuver region 38.
Furthermore, the articulation means 36 do not have a device to actuate the confinement part 14 towards its closed position.
Unlike the first kit 10, the confinement device 14 of the second kit 150 comprises means 154 of retaining the device 14 in its closed position.
In the example shown in Figures 7 and 8, the retaining means 154 comprise at least one mobile tab 156 comprising one end 158 fixed onto a first rigid portion 30A and a free end 160 intended to be engaged on an opposite surface of a facing second rigid portion 30B.
The tab 160 can be pivoted around its fixed end 158 relative to the first rigid portion 30A between a configuration in which the second rigid portion 30B is released, in which the free end 160 is kept at a distance from the second rigid portion 30B and a configuration holding the second rigid portion 30B in which the rigid portions 30A, 30B and the half shells 70A, 70B are kept inserted between the free end 160 and the related end 158 of the tab 160 in its closed position.
In one variant shown in Figure 9, the retaining means 154 comprise a click-fit tab 166 fixed to a first rigid portion 30A. The facing rigid portion 30B comprises a through orifice 168 through which the tab 166 is inserted and retained.
In one variant shown in Figure 10, the peripheral seal 74 of each half shell 70A, 70B comprises two parallel lips 180 delimiting a peripheral groove 182 between them. When in the closed position, the lips 180 of each seal 74 are pressed in contact with the lips 180 of the facing seal 74.
In the variant shown in Figure 11, each seal 74 comprises a bearing rim 184 that projects beyond the frame 44. In the closed position, the bearing rim 184 of the seal 74 of each half-shell 70A is applied onto the corresponding bearing rim 184 of the seal 74 of the facing half-shell 70B.
A third kit 190 according to the invention is shown in Figure 12. Unlike the first kit 10, the second kit 190 comprises a retaining means 154 holding the device 14 in its closed position. The retaining means 154 comprises a clamping lever 192 installed free to move between the maneuver regions 38.
The user can move the lever 192 to separate the regions 38 and to hold them apart.
Accordingly, the lever 192 is articulated on a region 38 by which a first rigid portion 30A is maneuvered, opposite the half-shells 70A relative to the articulation axis 62.
The lever 192 comprises a clamping region 194 and an actuation head 196 that projects from the clamping region 194 into a slit 198 formed in the maneuver region 38 of a second rigid portion 30B.
The clamping portion 194 slides on an inclined surface 200 of the maneuver region 38 of the second rigid portion 30B facing the first rigid portion 30A.
After the device 14 has been put into its closed position, the user actuates the actuation portion 196 to move the lever 192 towards the articulation axis 62.
During this displacement, the clamping portion 194 slides on the inclined surface 200 to move the maneuver region 38 of the first rigid portion 30A away from the maneuver region 38 of the second rigid portion 30B. This causes corresponding squeezing of the seals 74 facing the half- shells 70A, 70B supported by the support regions 40.
A fourth kit 210 according to the invention is shown in Figures 13 to 16.
Unlike the confinement device 14 in the first kit 10, each half- shell 70A, 70B comprises a hollow body 212 formed by a liner. The hollow body 212 defines a deformable peripheral seal 74 and a deformable wall 76 that will press in contact with the volume of keratin fibers.
The hollow body 212 has a substantially C-shaped cross-section. It thus comprises a substantially plane outer partition 214 fixed to the support region 40, a peripheral partition 215 and a concave inner partition 216 delimiting the extendable wall 76 and the seal 74.
The liner 212 is advantageously made by extrusion of the partitions 214, 216 and the longitudinal portions of the peripheral partition 215 through a constant section die, followed by closing off of the axial ends of the peripheral wall 216 to form a compressible internal volume 220.
The inner partition 216 has a concave central region forming the deformable wall 76 and a substantially plane peripheral region forming the seal 74.
The inner partition 216 is kept at a distance from the outer partition 214 to enable deformation of the seal 74 and the deformable wall 76 towards the outer partition 214 that will match the shape of the volume of keratin fibers 11, particularly when it is supported on a tensioning part 16.
As shown in Figure 16, each half- shell 70A, 70B thus forms a hollow region with axis B-B' substantially in the form of a half-cylinder. In the example shown in Figure 16, the hollow region opens up into a recess 92 at one axial end, to enable insertion of a tensioning part 16 for the keratin fibers 11.
The fourth kit 210 functions in a similar manner to the first kit 10.
Thus, once the group of keratin fibers 11 has been formed and possibly placed around a tensioning part 14, the maneuver regions 38 are moved towards each other to move the hollow bodies 212 apart and open the device 14. The volume of keratin fibers 11 is then inserted between the hollow bodies 212 and the confinement device 14 has changed over to its closed position.
During this displacement, the inner partition 216 deforms towards the inner partition 214 to match the volume defined by the keratin fibers 11 and to accommodate them.
The seal 74 of each hollow body 212 remains applied onto the facing seal 74 of the facing hollow body 212 to delimit a substantially sealed intermediate space 72 between them, possibly closed off in the axial direction by the electrical connection part 20.
The hollow body 212 is fixed onto the support region 40, for example by gluing or hot or cold force fitting, or by insert molding.
The maneuver regions 38 and the support regions 40 are advantageously formed from a single piece, for example by injection.
The terms "one", "two", etc. should be understood as meaning "at least one", "at least two", etc., unless mentioned otherwise.

Claims

Confinement kit (10; 150; 190; 210) for a cosmetic product, comprising:
- a device (14) for confinement of the cosmetic product on a volume of keratin fibers (11), of the type comprising two elements (28A, 28B) able to move relative to each other between an open position in which the volume of keratin fibers (11) can be put into place and a closed position for confining the volume of keratin fibers (11) in an intermediate space (72) defined between the elements (28A, 28B),
one of the mobile elements (28A, 28B) comprising a rigid portion (30A, 30B) and a deformable portion (32A, 32B) intended to be applied onto the volume of keratin fibers (11) to match the shape of the volume of keratin fibers (11),
the device (14) being arranged such that when in the closed position, the intermediate space (72) is closed off in a substantially leak tight manner when the volume of keratin fibers (11) is trapped between the two mobile elements (28A, 28B), and

- a tensioning assembly (12) for the volume of keratin fibers (11),
characterized in that:
- in the closed position, the tensioning assembly (12) partially closes off the intermediate space (72), and

- the tensioning assembly (12) comprises a tensioning part (16) comprising an outer surface (21) onto which the karatin fibers are intended to be applied, and

- the keratin fibers (11) are intended to be supported on the tensioning assembly (12), the tensioning assembly (12) being able to apply a shape to the volume of keratin fibers (11).
Confinement kit (10; 150; 190; 210) according to claim 1, characterized in that the tensioning assembly (12) comprises means (18) of modifying the temperature of keratin fibers (11) located in the intermediate space (72).
Confinement kit (10; 150; 190; 210) according to any one of the previous claims, characterized in that the intermediate space (72) is longitudinally extended along an elongation axis (B-B'), the mobile elements (28A, 28B) in their closed position transversally closing off and sealing at least one axial end of the intermediate space (72).
Confinement kit (10; 150; 190; 210) according to any one of the previous claims, characterized in that in the closed position, the intermediate space (72) is closed off over its entire periphery by the two elements (28A, 28B).
Confinement kit (10; 150; 190; 210) according to any one of the previous claims, characterized in that each mobile element (28A, 28B) comprises a peripheral seal (74) at least partly delimiting the intermediate space (72), the peripheral seals (74) of the mobile elements (28A, 28B) being applied to each other in the closed position.
Confinement kit (10; 150; 190; 210) according to claim 5, characterized in that each peripheral seal (74) of a mobile element (28A, 28B) delimits an application surface (82) on the peripheral seal (74) facing the other element (28A, 28B), the application surface (82) being substantially plane.
Confinement kit (10; 150; 190; 210) according to any one of the previous claims, characterized in that the deformable portion (32A, 32B) comprises the peripheral seal (74) and a deformable central wall (76) intended to be applied on the volume of keratin fibers (11), the peripheral seal (74) and the central wall (76) advantageously being all made of single piece.
Confinement kit (10; 190; 210) according to any one of the previous claims, characterized in that each mobile element (28A, 28B) comprises a rigid portion (30A, 30B) and a deformable portion (32A, 32B) intended to be applied to the volume of keratin fibers (11) to match the shape of the volume of the keratin fibers (11), each rigid portion (30A, 30B) delimiting a support region (40) for the deformable portion (32A, 32B) and a maneuver region (38) that a user can grip to move the mobile elements from their closed position to their open position, the device (14) advantageously forming a clip.
Confinement kit (10; 150; 190; 210) according to any one of the previous claims, characterized in that the deformable portion (30A, 30B) comprises an elastically extendable film, advantageously capable of reversibly increasing its area by at least 10%.
Confinement kit (210) according to any one of the previous claims, characterized in that the deformable portion (30A, 30B) comprises a hollow body (212) delimiting a compressible internal volume (220).
Method for cosmetic treatment of a volume of keratin fibers (11), of the type comprising the following steps:
- supply of a confinement kit (10; 150; 190; 210) according to any one of claims 1 to 10;

- insertion of the volume of keratin fibers (11) between the two mobile elements (28A, 28B) in their open position;

- moving the two mobile elements (28A, 28B) from their open position to their closed position to define a substantially sealed intermediate space (72).
Method according to claim 11, characterized in that, during the movement from the open position to the closed position, the deformable portion (30A, 30B) is applied onto the volume of keratin fibers (11) becoming deformed to match the shape of the volume of keratin fibers (11).