WO2020260230A1

WO2020260230A1 - Method for manufacturing a cosmetic article

Info

Publication number: WO2020260230A1
Application number: PCT/EP2020/067418
Authority: WO
Inventors: Jean-Marc Lebrand
Original assignee: L'oreal
Priority date: 2019-06-27
Filing date: 2020-06-23
Publication date: 2020-12-30
Also published as: KR20220010746A; FR3097725A1; FR3097725B1; JP2022538323A; CN114007459A; JP7345575B2

Abstract

A method for manufacturing a cosmetic article (1) comprising an open-cell polymer foam (15) that defines a surface (17) for applying, picking up or dispensing a cosmetic composition (C), including the step of carrying out a treatment involving melting at least one part of the foam (15).

Description

Title: Method for manufacturing a cosmetic article

Technical field

The present invention relates to the cosmetic field and more particularly, but not exclusively, to a method for manufacturing a cosmetic article intended for making up or caring for human keratin materials, in particular the skin, and also to the cosmetic article for picking up, dispensing or applying a cosmetic composition, obtained by implementing this method.

Prior art

The impregnation of a porous structure with a cosmetic composition is known, it being possible for a finger or an applicator to be brought into contact with said porous structure in order to be loaded with product.

Numerous patent applications deal with cosmetic articles of this type. In particular, the application WO 2017/016608 A1 can be cited, which discloses an article comprising a mat of fibers constituted by a nonwoven, covered on one face with a mesh.

Cosmetic articles are also known that comprise a case housing a reservoir of cosmetic composition surmounted by a screen, through which the composition is picked up by a finger or using an applicator. Different screens for the passage of composition are thus known from KR101380587 and KR 20140147706. WO 2016148371 describes an additional part positioned on the screen.

KR 101380587 describes a resilient dispensing lid, made of rubber or silicone, to be fitted on a cosmetic product container, having an elastic band, disposed around the perimeter of the lid and toward the bottom for fixing to the container, a thin peripheral film and, at the center, a reinforcing part having downwardly protruding portions, diffusing grooves and rectilinear or cruciform slots passing through the lid in the protruding portions. While the cosmetic product is being picked up by pressing on the dispensing lid using a powder puff, the lid is deformed, thereby opening the slots and making it possible to dispense the product through the lid toward the powder puff.

KR10-2016-0146510 describes a device for dispensing a cosmetic product through a dispensing surface by pressure exerted from the outside, this dispensing surface having, on at least one of its sides, at least one boss with convex protrusions or concave recesses. The dispensing surface can be wave-shaped in cross section. FR 3 052 649 relates to an applicator for cosmetic product, in particular a cleansing or care product, made at least partially from at least one porous material, comprising a first face, a second face opposite the first face, and an internal portion delimited by the first and second faces. At least one of the first and second faces, resulting from an at least partial felting treatment of the porous material(s). The applicator has a porosity gradient between at least one of the first and second faces for the one part, and the internal portion of the applicator, for the other part.

There is a need to benefit from a method for manufacturing a cosmetic article for picking up, dispensing or applying a cosmetic composition that affords the possibility of easily obtaining an aesthetic effect, if so desired, and skin contact with the article that are pleasant for the user, and also good releasing of the cosmetic composition.

The invention aims to provide a method for further improving cosmetic articles comprising a reservoir containing a cosmetic composition, and also such articles. A further aim of the invention is to propose a method for manufacturing a cosmetic article that can be used as an applicator and to propose such an article.

Disclosure of the invention

Method for manufacturing a cosmetic article

Therefore, a subject of the present invention, according to one of its aspects, is a method for manufacturing a cosmetic article comprising an open-cell polymer foam that defines a surface for applying, picking up or dispensing a cosmetic composition, including the step of carrying out a treatment involving melting at least one part of the foam.

By virtue of the invention, a method is provided for manufacturing an article that makes it possible, by treatment of the foam, to close some of the cells thereof in order to locally modify the permeability of the foam. The treatment can thus prevent or slow down the release of the cosmetic composition, at least in certain locations. This makes it possible to manage the dispensing of the composition through the surface of the foam, for example. The invention also makes it possible to create a decoration and/or a texture on the surface of the foam. The foam can in particular be marked, notably at the surface, by the treatment, in the manner of a decoration, but without it being necessary for an element, such as an ink or a film, to be transferred onto the foam. The treatment allows an impression to be left on the foam by melting a part of the foam, in particular locally. This allows a shape to be textured, imprinted, on the foam and makes it possible to modify the properties thereof, in particular permeability to the composition.

The method according to the invention makes it possible to precisely define the position of the one or more regions of the foam intended to be treated by melting.

The expression“melting at least one part of the foam” should be understood as meaning that one or more regions of the foam, as a result of the treatment carried out during the method according to the invention, pass(es) into a fluid, in particular liquid, state before solidifying again after treatment. The appearance of the foam is thus modified, as may be all or some of its mechanical properties, depending on the shape conferred by the treatment. Preferably, only a part of the foam is affected by melting, the treatment making it possible to treat only one or more regions of the foam. The treatment may or may not result in the creation of reliefs.

The treatment is advantageously not a hot roll treatment.

The expression treatment that is“not a hot roll treatment” should be understood as ruling out any type of treatment with a roll or cylinder that is driven in rotation and causes melting of at least one part of the foam, such as hot calendering. The advantage of a treatment that is carried out without the use of a roll is that it makes it easier to customize the pattern that is produced, if necessary, and that a foam can be treated under particular conditions, for example under tension or mounted on a holder, which are not possible with a roll treatment. Tensioning the foam during the treatment can help to produce a precise pattern, in particular when the foam exhibits a degree of elasticity.

In a variant, the treatment can be carried out with at least one roll.

The expression“treatment with at least one roll”, which may also be referred to as treatment with at least one cylinder, is understood as meaning a treatment in which at least one part of the foam is brought into contact with said at least one roll. The bringing of the foam into contact with said at least one roll can be effected with or without pressure. Said at least one roll may have a pattern in relief. In a variant, said at least one roll does not have a pattern in relief. When the treatment is carried out with more than one roll, for example with two rolls, just one of the rolls may have a relief. In a variant, the two rolls may have identical, complementary or different patterns in relief. The treatment with at least one roll may be chosen from mechanical finishing techniques. These are different than printing techniques. The treatment with at least one roll may be calendering, inter alia. Calendering is understood as meaning that at least one part of the foam passes between two or more heated rolls, which are calender rolls. At least one of the rolls may be etched, having a corresponding pattern in relief, which is or is not reversed, making it possible to create this pattern in relief on the foam.

The treatment preferably includes applying heat by conduction and/or by radiation and/or by ultrasound energy or radiofrequency energy.

The treatment is advantageously carried out by bringing the foam, in particular at least one surface of the foam, into contact with a treatment tool. In a variant, the treatment can be carried out with the treatment tool without contact with the foam.

In one embodiment, the treatment includes transfer-free hot marking, in particular using a heated pad and/or a heated iron.

The expression“transfer-free hot marking” is understood as meaning bringing the foam into contact with or into the vicinity of a hot marking tool such as a pad or an iron that is heated, for example electrically, and is equipped with a marking instrument, such as an etched block or an interchangeable type-carrier strip, without using a transfer film. In this case, the treatment tool comprises the marking tool with a marking instrument.

The treatment may also include applying ultrasound with the aid of a sonotrode, in particular a sonotrode with a relief or a flat sonotrode, and an anvil, in particular an anvil with a relief or a flat anvil. In this case, the treatment tool may have a sonotrode connected to an ultrasound generator and an anvil, the sonotrode advantageously being disposed on one side of the foam and the anvil being disposed on the other side of the foam during the treatment.

The method may include a step of applying a pressure to the foam, in particular embossing with an embossing tool. Such an application of pressure on the foam may make it possible to flatten the foam or a part thereof. It may be carried out during, before or after the treatment, particularly during the treatment, in particular to create a relief on the foam and/or reduce the thickness of the foam and/or densify the foam in order to modify the permeability thereof.

Other treatments may be carried out in order to effect the melting of at least one part of the foam, in particular a laser treatment or an induction treatment. The treatment can be carried out using a treatment tool that is brought into contact with or into the vicinity of the foam substantially perpendicularly to the surface of the foam, or even perpendicularly to the surface of the foam. This tool, unlike a roll, is not driven in rotation on itself.

The method may include the step of cutting the foam flat. This step is carried out preferably before the treatment. In a variant, it is carried out afterward. The invention may make it possible to obtain, in this case, a 3D foam, with a relief created by the treatment, proceeding from a flat foam.

In a variant, the method may include the step of cutting the foam in 3D, for example before said treatment. The expression cutting in 3D should be understood as meaning cutting that not only defines the contour of the foam as seen from above, but also shapes the relief thereof inside said contour.

The maximum thickness of the foam is preferably between 0.4 mm and 10 mm, in particular equal to around 1 mm. This thickness can be measured before the treatment according to the invention is carried out. In a variant, this thickness can be measured after treatment. The treatment, in particular in the case of application of a pressure, may make it possible to reduce the thickness of the foam, by a factor of 2 or more. A relief curved on the basis of a cylinder may be envisioned.

The method may include the step of flocking the foam. This flocking step may take place before and/or after the treatment is carried out.

The method may include the step of making at least one hole in the foam. This step of making (a) hole(s) may take place before and/or after the treatment is carried out. The hole(s) may make it possible to create one or more preferential dispensing regions for the cosmetic composition through the foam.

In one particular embodiment, no tension is exerted on the foam while the method is being carried out.

In a variant, the method may include the step of applying tension to the foam along at least one stretching axis, before said treatment and/or during said treatment, in particular a tension causing an elongation of between 3% and 10%. This tension is thus advantageously applied in the plane defined by the surface of the foam. This can make it possible to obtain a more visible aesthetic effect on the foam after the treatment, if the tension is released after the treatment. The tension applied during the treatment may be greater than that which is applied during the use of the article, apart from tension exerted by the user, for example when picking up composition through the foam.

Since the foam has a contour, in particular a circular contour, at its periphery, the tension can be exerted around the entire periphery of the foam, in particular in a uniform manner.

The method may include the step of fixing the foam to a holder of the article. Such a holder may be a frame. The fixing of the foam to the frame before the treatment can allow better management of the location of said at least one part of the foam undergoing melting. In particular, one or more patterns obtained by the treatment can be centred more easily. When the foam is fixed to a frame of the cosmetic article before the treatment is carried out, the treatment tool can be configured, for example by complementing shapes between a sonotrode and an anvil around the frame, to ensure that it is positioned relative to the frame and therefore to precisely manage the location of said at least one part of the foam that is melted during the treatment. The frame can have various shapes, with or without symmetry of revolution, for example a circular or polygonal shape. The frame may be circular and form a ring.

The foam can be fixed to the frame without tension, the tension being able to be applied during the treatment only, in particular using the treatment tool.

The foam can be fixed to the frame simultaneously with the treatment. The foam can be fixed to the frame by bonding, welding, or by any other fixing means. The tool that causes the local melting of the foam, in particular forming a pattern thereon, can also ensure that the foam is fixed to the frame by local melting of material. Thus, a single operation makes it possible to obtain both the fixing of the foam and the treatment thereof.

The method may include the step of fixing the foam to a textile, in particular by ultrasonic welding, in order to form a two-layer screen.

Cosmetic article

A further subject of the present invention, according to another of its aspects, in combination with the above, is a cosmetic article comprising an open-cell polymer foam that defines a surface for applying, picking up or dispensing a cosmetic composition, the article being obtained using the method as described above.

In one embodiment, said surface has undergone said treatment. In a variant or additionally, the reverse side of said surface has undergone said treatment.

The foam may have a relief, resulting from the treatment, on the treated surface, in particular a relief having a depth greater than or equal to 0.5 mm or forming a protrusion of 0.5 mm or more.

The open-cell polymer foam is preferably chosen from the group constituted by foams of polyurethane, butadiene rubber (BR), styrene -butadiene rubber (SBR), natural rubber (NR), wetted urethane, dry urethane, poly ether, polyester, polyvinyl chloride, polyolefins, in particular polyethylene, ethylene vinyl acetate (EVA), latex, silicone, styrene - isoprene-styrene (SIS), polyvinyl alcohol (PVA), silicone elastomer, nitrile rubber, butyl rubber and neoprene, thermoplastic elastomers.

Generally, a polymer foam is understood as being a cellular material made from a polymer and constituted of a three-dimensional structure formed by a solid skeleton having solid walls and/or solid ridges, surrounding cells, with spatially random orientations.

In a polymer foam, the porosity, which is all of the voids created by the pores, or cells, exceeds generally 70% of the total volume of the foam.

An“open-cell polymer foam” is understood to mean that a majority of the cells of this material are open to the adjacent cells and to the outside, at least before treatment according to the method of the invention. In this case, it is only ridges surrounding the cells that form the solid skeleton of the foam. There are no solid walls. The shape of the cells may be spherical or polyhedral. There may be a minority of closed cells, i.e. in an amount strictly less than 50% of the total amount of cells in the foam, in particular less than 20%, or even less than 10% of the total amount of cells in the foam.

The number of cells per unit length, referred to as PPI (Pores Per Inch), makes it possible to characterize the polymer foam. It corresponds to the number of pores, or cells, intercepted in a length of 1 inch (2.54 cm).

The structure of the foam may be modified by the treatment. In particular, the number of cells per unit length (PPI) may be modified after treatment. The porosity of the foam may be at least locally reduced so as to reduce the permeability of the foam, without necessarily closing up the foam or by locally closing up the cells of the foam. The properties of the foam may have been modified by the treatment. The foam is for example locally impermeable or has reduced permeability in one or more regions of the foam that has undergone the treatment, for example in a central region.

The porosity of the foam can be modified by the treatment, in the intended way, in particular toward lower porosity. The foam may retain permeability to the cosmetic composition. It is possible for the porosity not be uniform within the surface. The treated region of the foam may be a central region and not cover the full extent of the foam.

The foam may have at least one pattern resulting from the treatment. The foam may have at least one relief resulting from the treatment, in particular a relief having a depth greater than or equal to 0.5 mm or forming a protrusion of 0.5 mm or more. When present, the relief can take on multiple pattern shapes. The pattern, optionally in relief, can be geometric, regular or irregular.

The foam may be flocked over at least one part of the surface in order to apply, pick up or dispense the cosmetic composition.

The article may have a holder, in particular a frame, which is fixed or movable within the article, the foam being held by the holder above a reservoir of composition such that the composition can pass through the foam, in particular by the foam being pressed against the composition. The foam can then act as a screen.

The foam may be fixed, in particular by bonding, to an underlying porous structure, in particular a sponge, optionally impregnated with the cosmetic composition.

The article may have a case having a body that has a housing containing the cosmetic composition, the foam being disposed above the cosmetic composition, the case preferably having a lid designed to cooperate with the body.

In a variant, the article forms a cosmetic composition applicator. In this case, the article can form a pad or powder puff. The article can then be washable. In a variant, the applicator is fixed to a gripping part.

The cosmetic composition may be liquid or pulverulent.

Brief description of the drawings

The invention may be understood better from reading the following detailed description of nonlimiting implementation examples thereof and from studying the appended drawing, in which: [Fig 1] figure 1 is a schematic perspective view of an example of a case of an article according to the invention,

[Fig 2] figure 2 shows a schematic view of an application, pick-up or dispensing surface of another example of foam of an article according to the invention,

[Fig 3] figure 3 shows a schematic view of an application, pick-up or dispensing surface of another example of foam of an article according to the invention,

[Fig 4] figure 4 shows a schematic view in cross section of a part of an example of an article, before treatment according to the method of the invention,

[Fig 5] figure 5 is a partial schematic view in cross section illustrating the implementation of the method according to the invention on an example of an article,

[Fig 6] figure 6 is a schematic view in cross section of another implementation example of the method on a foam intended for producing a cosmetic article,

[Fig 7] figure 7 schematically shows, in cross section, a foam after treatment according to the method of the invention,

[Fig 8] figure 8 shows a partial, schematic and perspective view of an example of a tool for implementing the method according to the invention,

[Fig 9] figure 9 shows a partial, schematic and perspective view of another example of a tool for implementing the method according to the invention, positioned close to the foam before the treatment is carried out,

[Fig 10] figure 10 shows the carrying out of the treatment step of the method according to the invention with the tool in figure 9 on the foam in figure 9,

[Fig 11] figure 11 shows a partial, schematic view in cross section of another example of a cosmetic article according to the invention,

[Fig 12] figure 12 schematically shows a front view of another example of a cosmetic article according to the invention,

[Fig 13] figure 13 schematically shows a front view of another example of a cosmetic article according to the invention, and

[Fig 14] figure 14 schematically shows, in cross section, a foam after treatment according to the method of the invention.

Detailed description

In the rest of the description, elements that are identical or have identical functions bear the same reference signs. In order to make the present description concise, they are not described for each of the figures, only the differences between the embodiments being described.

Figure 1 shows a cosmetic article 1 according to the invention, having a case 2 that has a body 3. The case 2 also has a lid 5, which in this example is hinged to the body 3. It can be fixed in some other way, for example screwed thereto.

The case 2 also houses an applicator holder 6, which in this example is hinged to the body 3 about an axis of rotation that is perpendicular to that of the hinge between the lid 5 and the body 3. The applicator is not shown in this figure. A dish 4 is received in a housing 8 of the body 3 of the case 2. The dish 4 accommodates a reservoir of cosmetic composition.

The reservoir is surmounted by a foam 15 that defines a surface 17 for applying, picking up or dispensing the composition, forming the visible side of the foam 15, with a substantially square shape with edges and comers that are rounded, in this example. The foam 15 is an open-cell polymer foam, made in this example of polyurethane foam. At least one part of the foam 15, in this example at least one part of the surface 17, has been treated by a treatment, which is not a hot roll treatment, involving melting at least one part of the foam 15, at least at the surface. In particular, in this example, the treatment involves melting at least some walls of cells of the foam 15.

In the example illustrated, a part of the surface 17 of the foam has been treated by transfer-free hot marking, in particular with a heated iron or a heated pad, so as to form, by melting, a pattern 20 in the form of the letter A, in this example. By virtue of the invention, the pattern is properly centred on the surface 17. In this case, heat is applied to the foam 15 by conduction.

In this example, the foam 15 is intended to make it possible to pick up a cosmetic composition contained in the underlying reservoir. The foam 15 is permeable to the composition and allows the composition to pass through the open cells of which it is made up. The treatment can modify, in particular reduce, the permeability of the foam 15 in the region of the pattern 20.

Most of the cosmetic composition is contained in the reservoir, in particular entirely contained therein, for example in liquid form.

If the treatment includes applying heat by radiation and/or by ultrasound energy or radiofrequency energy, or if the treatment is effected by a treatment involving applying ultrasound using a sonotrode, or a laser treatment or else a treatment by induction or some other suitable treatment, other than a treatment with a hot roll, this does not constitute a departure from the scope of the invention. If it is the reverse of the surface 17 that undergoes the treatment, rather than the surface 17 or in addition to the surface 17, this also does not constitute a departure from the scope of the invention. The treatment can also affect all or part of the foam situated between the surface 17 and the reverse of the surface 17.

Figure 2 shows, on its own, a surface 17 of foam 15 mounted on and fixed to a circular frame 21, treated so as to form, by local melting of the foam 15, a central pattern 20, in the form of a ring in this example, realized by applying heat by ultrasound energy, using a sonotrode.

In the example in figure 3, the surface 17 of foam 15 has been treated by applying ultrasound so as to form a geometric pattern 20 in the form of concentric circles, in the manner of a target, around a central point O of the surface. Each circle of the pattern 20 forms a local melting region of the foam 15, at least at the surface, so as to form the pattern 20 and possibly to modify the properties of the surface, for example to reduce the permeability of the foam 15 in these regions.

Since the treatment is preferably not effected with a roll, it is easier to have a pattern 20 centred within the article 1, as is the case in figure 3.

Figure 4 illustrates the foam 15 extending perpendicularly to the axis X, the foam 15 being fixed, in this example by bonding, at its periphery 16 to the frame 21, before the treatment of the method according to the invention. This figure also shows the reverse side 18 of the foam 15, which extends on the opposite, reverse, side of the surface 17. In this example, the foam 15 is stretched on the frame 21 with an elongation of around 3%, along at least one stretching axis, in this example around the entire periphery, which is for example circular, of the foam 15.

Figure 5 shows a hot marking tool O moved into the vicinity of the surface 17, perpendicularly thereto along the arrows, parallel to the axis X, in order to carry out the treatment. The tool O has a surface with elements R in relief, in particular for producing the pattern on the surface 17 of the foam 15.

In the example in figure 5, the foam 15 is mounted on a frame 21 of the cosmetic article, this being the first step in producing the article, before the latter is fitted inside a case similar to the one in figure 1, for example. Thus, the production of the article 1 begins before the treatment is carried out. It is possible to add a temporary holder E under the foam for carrying out the hot marking, as is illustrated by dashed lines in this figure.

It is possible for the foam 15 to be treated before the article 1 is produced. For example, a 2D sheet 12, for example cut flat, of foam 15, as illustrated in figure 6, is treated as in the example in figure 5, before the foam 15 is cut for use in an article according to the invention. The thickness of the foam 15 before treatment is around 1 mm in this example. The foam can rest on a holder during the treatment.

Figure 7 shows that the treatment carried out on the foam 15 can involve the formation of relief(s) 25 on the foam 15, recessed on the side of the surface 17 and protruding on the reverse side 18, in this example, in particular by a pressure being applied to the foam during, before or after the treatment.

In a variant, as illustrated in figure 14, the relief 25 may be present only on the surface 17, and in the thickness of the foam, without affecting the reverse-side surface 18 of the foam 15.

Figure 8 shows an example of a pad for a hot marking tool O with an A-shaped pattern allowing an A-shaped pattern 20 to be obtained on the surface 17 of the foam 15. The diameter and the shape of the surface S of the pad that will be in contact with the foam 15 during the treatment may be similar to those of the foam on the finished cosmetic article 1. The treatment can be effected without contact with the foam, without departing from the scope of the invention, for example using a laser.

Figures 9 and 10 illustrate the implementation of the treatment using a sonotrode D on the foam 15 mounted on a frame 21. In figure 9, the treatment tool comprises the sonotrode D, connected to an ultrasound generator (not shown in the figure for the sake of clarity of the drawing) extending from the reverse side 18, in abutment against an opposite end of the frame 21 from the end of the frame 21 that is fixed to the foam 15, so as to be kept at a non-zero distance from the reverse side 18 of the foam 15. The tool also has an anvil E disposed on the opposite side, on the side of the surface 17 of the foam 15, in contact therewith. The anvil E has a peripheral rim on the upper part that comes into contact with the sonotrode D and fully surrounds it, corresponding to complementing shapes between the anvil E and the sonotrode D, around the frame 21 supporting the foam 15. Thus, the sonotrode D is positioned in a centered manner on the frame 21, thereby allowing precise management of the location of the one or more zones of the foam 15 that are subsequently treated. In order to melt at least one part of the foam 15, as illustrated in figure 10, the anvil E is brought closer so as to tension the foam 15 until the reverse side 18 comes into contact with the sonotrode D and heat is applied by ultrasound energy, the application of ultrasound causing the melting of at least one part of the foam, in particular of cells of the foam, in the desired pattern.

In figure 1, the foam 15 is in contact with the cosmetic composition at least after a first use.

In the example in figure 11, the foam 15 is fixed by bonding to an underlying structure 35, which is made up in this example of a sponge or a block of cellular porous material containing the cosmetic composition C at least during use. In this example, the surface 17 of the foam does not have a relief, the treatment involving melting at least one part of the foam 15 that has not created a relief.

The invention is not limited to cosmetic articles 1 that come into contact with the composition in a reservoir.

In particular, the variants illustrated in figures 12 and 13 show a cosmetic article 1 with a foam 15 covering for example a sponge (not visible) for forming a cosmetic composition applicator that is not impregnated with composition. This applicator is used to pick up the composition from a surface loaded with composition or from a block of product and to apply it while it is being held in the hand, or, in a variant, is used to blend or withdraw the composition applied in some other way.

The applicator in figure 12 is entirely flexible. The applicator in figure 13 has an end piece 28 that is covered with the foam 15 and fixed to a rigid or semi-rigid gripping part 29, forming a stem in this example.

The foam 15 may or may not have holes, independently of the cells.

Claims

1. A method for manufacturing a cosmetic article (1) comprising an open-cell polymer foam (15) that defines a surface (17) for applying, picking up or dispensing a cosmetic composition (C), including the step of carrying out a treatment involving melting at least one part of the foam (15).

2. The method as claimed in claim 1, wherein said treatment includes applying heat by conduction and/or by radiation and/or by ultrasound energy or radiofrequency energy.

3. The method as claimed in claim 1 or 2, wherein the treatment includes transfer-free hot marking, in particular using a heated pad and/or a heated iron.

4. The method as claimed in any one of the preceding claims, wherein the treatment includes applying ultrasound with the aid of a sonotrode, in particular a sonotrode with a relief or a flat sonotrode, and an anvil, in particular an anvil with a relief or a flat anvil.

5. The method as claimed in the preceding claim, including a step of applying a pressure to the foam (15), in particular embossing with an embossing tool, in particular simultaneously with said treatment.

6. The method as claimed in any one of the preceding claims, the treatment not being a hot roll treatment.

7. The method as claimed in any one of the preceding claims, including the step of cutting the foam (15) flat.

8. The method as claimed in any one of the preceding claims, wherein the maximum thickness of the foam (15) is between 0.4 mm and 2 mm, in particular equal to around 1 mm.

9. The method as claimed in any one of the preceding claims, including the step of fixing the foam to a holder of the article.

10. The method as claimed in any one of the preceding claims, including the step of fixing the foam to a textile in order to form a two-layer screen.

11. The method as claimed in the preceding claim, wherein the foam is fixed to the textile by ultrasonic welding.

12. A cosmetic article comprising an open-cell polymer foam (15) that defines a surface (17) for applying, picking up or dispensing a cosmetic composition (C), the article (1) being obtained using the method as claimed in any one of the preceding claims.

13. The article (1) as claimed in the preceding claim, wherein said surface (17) has undergone said treatment.

14. The article (1) as claimed in claim 12 or 13, wherein the reverse side (18) of said surface (17) has undergone said treatment.

15. The article as claimed in any one of claims 12 to 14, wherein the foam (15) has a relief (25), resulting from the treatment, in particular a relief having a depth greater than or equal to 0.5 mm or forming a protrusion of 0.5 mm or more.

16. The article as claimed in any one of claims 12 to 15, the open-cell polymer foam (15) being chosen from the group constituted by foams of polyurethane, butadiene rubber (BR), styrene-butadiene rubber (SBR), natural rubber (NR), wetted urethane, dry urethane, polyether, polyester, polyvinyl chloride, polyolefins, in particular polyethylene, ethylene vinyl acetate (EVA), latex, silicone, styrene-isoprene-styrene (SIS), polyvinyl alcohol (PVA), silicone elastomer, nitrile rubber, butyl rubber and neoprene, thermoplastic elastomers.

17. The article as claimed in any one of claims 12 to 16, the structure of the foam (15) having been modified by said treatment.

18. The article as claimed in any one of claims 12 to 17, the foam (15) being locally impermeable or having reduced permeability in one or more zones of the foam (15) that have undergone the treatment.

19. The article as claimed in any one of claims 12 to 18, the foam (15) having on the treated surface at least one pattern resulting from the treatment.

20. The article (1) as claimed in any one of claims 12 to 19, having a holder, in particular a frame (21), which is fixed or movable within the article, the foam (15) being held by the holder (21) above a reservoir of composition (C) such that the composition can pass through the foam, in particular by the foam being pressed against the composition.

21. The article (1) as claimed in any one of claims 12 to 20, the foam (15) being fixed, in particular by bonding, to an underlying porous structure (35), in particular a sponge, optionally impregnated with the cosmetic composition.

22. The article (1) as claimed in any one of claims 12 to 21, having a case (2) having a body (3) that has a housing containing the cosmetic composition, the foam (15) being disposed above the cosmetic composition, the case (2) preferably having a lid (5) designed to cooperate with the body (3).

23. The article (1) as claimed in any one of claims 12 to 19, forming a cosmetic composition applicator.