EP4007557A1

EP4007557A1 - Stick of cosmetic product comprising two compositions, method and device for manufacturing such a stick of cosmetic product

Info

Publication number: EP4007557A1
Application number: EP20820481.8A
Authority: EP
Inventors: Thierry Chartier; Rémi BARRAULT
Original assignee: Parfums Christian Dior SA
Current assignee: Parfums Christian Dior SA
Priority date: 2019-08-02
Filing date: 2020-08-01
Publication date: 2022-06-08
Also published as: KR20220045969A; CN114423399A; WO2021023938A1; FR3099366B1; FR3099366A1

Abstract

A cosmetic stick, in particular lipstick, comprises (X-X) of the cosmetic stick of such kind as the first cosmetic stick composition. The first composition (A) is self-supporting. The inner surface of the first composition (A) has at least one relief.

Description

Title: STICK OF A COSMETIC PRODUCT CONSISTING OF TWO COMPOSITIONS, METHOD AND DEVICE FOR MANUFACTURING SUCH A STICK OF A COSMETIC PRODUCT

Technical area

The present invention relates to cosmetic product sticks including lipstick or complexion product, comprising two compositions. More particularly, the invention relates to a stick of cosmetic product comprising two compositions, for example of the heart-sheath type, in particular a stick of lipstick of the heart-sheath type, having a decorative surface portion in relief , a process of the heart-sheath type and to a device for manufacturing such a stick of cosmetic product, it should be noted throughout what follows that the invention relates to a stick of cosmetic product comprising at least two compositions, that is, that is, it could have more than two different compositions.

Prior art

[0003] Document FR-A-2417980 describes a lipstick stick of the heart-sheath type and a device for manufacturing such a lipstick stick.

The lipstick stick described in FR-A-2417980 has two compositions forming two substantially cylindrical portions, which extend coaxially, such that one composition extends around the other composition. In fact, the manufacturing device used in this document comprises a rigid mold in which the stick of lipstick is cast or injected in two stages. [0005] Document FR-A-2823082 describes a lipstick stick having a decorative surface portion in hollow relief, and a device for manufacturing such a lipstick stick.

[0006] The stick of lipstick described in FR-A-2823082 is produced by casting or injection into an elastic mold. However, the mold described in this application does not allow the casting or injection of two compositions to form a sheath surrounding a core.

[0007] The aim of the present invention is in particular to produce a stick of cosmetic product comprising two compositions, at least one of which has a decorative surface portion.

Disclosure of the invention

[0008] To this end, there is provided a stick of cosmetic product, in particular lipstick, comprising first and second compositions extending along a longitudinal axis of the stick of cosmetic product such that the first composition extends around the second composition over at least a portion of the stick of cosmetic product, the first composition being self-supporting, the internal surface of the first composition having at least one relief.

[0009] In preferred embodiments, one can optionally also have recourse to one and / or the other of the following arrangements, taken alone or in combination:

- the first composition is translucent or transparent, the second composition preferably being colored

- the second composition is self-supporting; the external surface of the second composition has at least one relief complementary to the at least one relief of the internal surface of the first composition;

- the second composition is a viscous liquid or gel;

- the stick of cosmetic product is of the core-sheath type, the first and second compositions being arranged relative to each other to form a heart surrounded by a sheath along the longitudinal axis, the sheath having an internal lateral surface having said at least one relief;

- the stick of cosmetic product has a bevelled free end;

- the sheath has a constant thickness at the bevelled free end around the core;

- at the level of the bevelled free end, the core is concentric with the sheath;

the at least one relief on the radially internal surface of the first composition is protruding towards the second composition or recessed in the first composition; and - the at least one relief on the radially inner surface of the first composition has a hole passing radially through the first composition, the second composition preferably extending through the hole to the radially outer surface of the first composition.

According to another aspect, there is described a method of manufacturing a stick of cosmetic product, in particular lipstick, comprising a first composition and a second composition, the first and second compositions extending along a longitudinal axis of the stick of cosmetic product, such that the first composition extends around the second composition over at least a portion of the stick of cosmetic product, the first composition being self-supporting, the internal surface of the first composition having at least one relief, the method comprising:

- the placement of a deformable core in a bucket, the core having a substantially cylindrical or frustoconical surface with at least one relief,

- molding, in particular by casting or injection, of a first composition between the core and the cup to form a first element,

- removing the core from the bucket,

- the casting or injection of a second composition to form a second element at least partially inside the first element, thus forming a stick of cosmetic product, and - a step of unmolding the stick of cosmetic product from the cup . In preferred embodiments, one can optionally also have recourse to one and / or other of the following arrangements, taken alone or in combination:

- the method comprises lubricating the core; and - the core is withdrawn from the bucket after having deformed the core, in particular contracted the core.

It is also described, according to another aspect, a device for manufacturing a stick of cosmetic product, in particular lipstick, comprising first and second compositions extending along a longitudinal axis of the stick of cosmetic product such that the first composition extends around the second composition over at least a portion of the stick of cosmetic product, the first composition being self-supporting, the internal surface of the first composition having at least one relief, the device comprising:

- a base comprising a cavity formed in the base, - a cup received in the cavity,

a core movable in translation between an inserted position in which the core is positioned in the bucket, the core coming into contact with the bottom of the bucket, and a withdrawn position in which the core is withdrawn from the bucket, the core being deformable, the core having a substantially cylindrical or frustoconical shape with at least one relief on its lateral surface, and

- a means to deform the core so that the core can be extracted from the cup after having molded the first composition in the space between the cup and the core.

[0013] This device allows in particular the manufacture of a stick of cosmetic product, in particular lipstick, of the heart-sheath type, extending along a longitudinal axis, comprising two compositions A and B arranged the relative to each other to form a heart surrounded by a sheath along the longitudinal axis, the sheath having an inner side surface having a decorative surface portion in relief. In preferred embodiments, one can optionally also have recourse to one and / or other of the following arrangements, taken alone or in combination:

- the cup is smaller than the size of the cavity so as to define a space between the cup and the cavity, and

- the bucket has a means to depressurize the space. - The core comprises a deformable nipple, defining a sealed internal space, and a channel, said channel placing said internal space in fluid communication and a device for pressurizing and / or depressing the closed internal space;

- The device further comprises a means of adjusting the pressure exerted by the core on the bottom of the bucket;

- the pressure adjustment means comprises a spring;

- The device further comprises means for guiding in translation and centering the core in the bucket;

- The translational guide and centering means is retractable; - The device further comprises a magnetization means making it possible to maintain the guiding means in translation and centering in the retracted position;

- The core and the translational guide and centering means are mounted on a block;

- The translational guide and centering means comprises a centering ring adapted to cooperate with a housing provided in the base; and

- the device comprises a plurality of cavities, a plurality of cups and a plurality of cores, each core having a substantially cylindrical or frustoconical shape with at least one relief on its lateral surface, in which the plurality of cavities is formed in the base, wherein each of the cups is received in a respective cavity, and wherein each of the cores is movable in translation between an inserted position in which the core is positioned in a bucket and a withdrawn position in which the core is withdrawn from the bucket.

Brief description of the drawings

[0015] Other characteristics and advantages of the invention will become apparent from the following description of one of its embodiments, given by way of non-limiting example, with reference to the accompanying drawings. [0016] In the drawings:

[0017] Figure 1A is a front view of an example of a cosmetic product stick;

[0018] Figure 1B is a side view of the stick of cosmetic product of Figure 1A;

[0019] FIG. 2 is an exploded perspective view of an example of a device for manufacturing a stick of cosmetic product according to FIG. 1A;

[0020] FIG. 3A is a perspective view of the device of FIG. 2, the cores being outside the cups; FIG. 3B is a perspective view of the device of FIG. 2, the cores being inserted into the cups;

[0022] Figure 4A is a partial sectional view of the device of Figure 3B along line IV-IV, the translational guide and centering means being retracted, the cores not being shown for better visibility; Figure 4B is a partial sectional view of the device of Figure 3B along line IV-IV, the translational guide and centering means being deployed and in contact with the reduction plate, the cores not being not shown for better visibility;

Figure 4C is a partial sectional view of the device of Figure 3B along line IV-IV, the translational guide means and centering being deployed and at a distance from the reduction plate, the cores not being not shown for better visibility;

Figure 5 is a sectional view of the device of Figure 4 along the line V-V; [0026] FIG. 6A is a view of an example of a core that can be implemented in the device of FIG. 4;

[0027] FIG. 6B illustrates a first variant of the reinforcement of the core of FIG. 6A; [0028] FIG. 6C illustrates a second variant of the frame of the core of FIG. 6A;

[0029] Figure 7A is a sectional view of the base of the device of Figure 5 with the sheath cast in the cup; Figure 7B is a sectional view of the base of the device of Figure 5 with the heart cast in the sheath;

Figure 8 is a sectional view of the base of the device of Figure 5 with the heart cast in the sheath; and

[0032] Figure 9 is a flowchart schematically illustrating the steps of an example of a method of manufacturing a stick of cosmetic product of Figures 1 A and 1 B.

detailed description

In the various figures, the same references designate identical or similar elements. FIGS. 1A and 1B represent an example of a stick of cosmetic product 10. The stick of cosmetic product is in particular a stick of lipstick.

The stick of cosmetic product 10 extends along a longitudinal axis XX. The cosmetic product stick 10 comprises two compositions A, B extending along the longitudinal axis XX. The stick of cosmetic product 10 is here of the heart-sheath type, comprising two compositions A, B arranged relative to each other to form a heart 12 surrounded by a sheath 14 along the longitudinal axis XX. More precisely, in this case, the core 12 is in the second composition B while the sheath 14 (or shell) is in the first composition A. In the remainder of the description, the stick of cosmetic product 10 is of the core type. -sheath, but it should be understood that the present description is applicable to any type of stick of cosmetic product 10 comprising two compositions A, B extending along a longitudinal axis XX of the stick of cosmetic product, such as that the first composition A extends around second composition B over at least one longitudinal portion of the stick of cosmetic product.

The two compositions A, B are here cosmetic products which enter into the composition of the cosmetic product sticks and which are preferably visually distinct. The first composition A is self-supporting. The second composition B can be self-supporting. Alternatively, composition B is a gel or a viscous liquid. Preferably, the first and second compositions A, B are incompatible in that they do not mix.

As visible in Figures 1A and 1B, the sheath 14 of the stick of cosmetic product 10 has a decorative surface portion S in relief on the internal lateral surface 14i of the sheath 14 of the stick of cosmetic product 10. In the In this case, the relief on the internal lateral surface of the sheath 14 is a protruding relief, that is to say oriented substantially in a radial direction, towards the core 12. Facing this projecting relief, the core 12 has a hollow relief, complementary to this projecting relief. So that the decorative surface S is visible, the first composition A is advantageously translucent or even transparent. The second composition B is advantageously colored. The outer surface of the sheath 14 is here substantially smooth.

The stick of cosmetic product 10 has a free end 10A and, opposite the latter, an end 10B which is fixed to a dispensing mechanism 16 of known type. The end 10A may be in the form of an ogive. The cosmetic stick 10 may be bevelled at the free end 10A, as best seen in FIG. 1B. This bevel is off-center due to the domed shape of the pointed end of the stick of cosmetic product 10. [0039] Furthermore, the sheath 14 may have at the level of the bevelled free end 10A a constant thickness around the core 12. measured in the plane of the bevel. More particularly, at the level of the bevelled free end 10A, the sheath 14 has a thickness 14 'which is constant all around the core 12. It is described later in the description in which way it is possible to obtain this thickness 14. constant while the free end 10A is bevelled. [0040] The cross section of the stick of cosmetic product 10 is preferably of generally circular shape. However, the cross section of the stick of cosmetic product 10 may have any other shape accessible to those skilled in the art. Likewise, the cross section of the heart 12 is preferably of generally circular shape. However, the cross section of the heart 12 may have any other shape accessible to those skilled in the art, in particular oval, teardrop, polygonal, in particular star.

[0042] Figure 2 shows an exploded view of an example of device 100 for implementing an example of a method of manufacturing a stick of cosmetic product 10 as illustrated in Figures 1 A and 1 B.

The device 100 thus makes it possible to manufacture a stick of cosmetic product 10, in particular lipstick, comprising two compositions A, B, extending along a longitudinal axis XX, such as the first composition A s' spreads around the second composition B over at least a portion of the stick of cosmetic product, in particular over a longitudinal portion of the stick of cosmetic product. In particular, the device 100 makes it possible to manufacture a stick of a cosmetic product, in particular a lipstick, of the heart-sheath type.

As illustrated in Figure 2 in particular, the device 100 comprises a base 18 with at least one cavity 20 formed in the base 18. Preferably, the base 18 comprises a plurality of cavities 20 thus allowing simultaneous manufacture. of several sticks of cosmetic product 10. In this case, as shown in the figures, the base 18 has six cavities 20, but it may have a different number (lower or higher). As illustrated, the device 100 further comprises at least one cup 22, received in a cavity 18. For reasons of physicochemical compatibility with the compositions A, B, the cup 22 is preferably formed from of a material that does not present any risk of interaction with these compositions A, B. In particular, the cup 22 is made of a material to which the compositions A, B do not adhere. The cup 22 is preferably made of a more rigid material than the compositions A, B. The internal surface of the cup 22 is advantageously covered with a material limiting or even preventing the adhesion of the compositions A, B on this internal surface of the cup 22. For example, the internal surface of the cup 22 is covered with a film of rubber or silicone. As shown in the figures, the device 100 may in particular comprise six cups 22 which are each received in one of the six cavities 18. In this case, each of the cups 22 has a radially internal surface that is substantially cylindrical.

According to the example illustrated, the device 100 further comprises at least one core 24 which is movable in translation along a longitudinal axis XX between an inserted position, illustrated in FIG. 3B, in which each core 24 is positioned in a respective cup 22, and a withdrawn position, illustrated in FIG. 3A, in which each core 24 is withdrawn from its associated cup 22.

As illustrated by Figures 6A-6C, each core 24 preferably comprises a rigid frame 50 partially covered with a deformable teat 52, preferably elastic. The teat 52 is for example made of silicone. The pacifier 52 has a decorative surface portion S ', here in projecting relief. Two examples of frames 50 are illustrated in Figures 6B and 6C. In each case, the frame 50 comprises a duct opening out on the one hand at its lower end 54 intended to be placed opposite a bevelled end 24A of the core 24 and, on the other hand, at a location 56 intended to be outside the cup 22, even when the core 24 is (partially) inserted into the cup 22. In the example of FIG. 6B, a plurality of outlets 58 are further provided in the lower part of the cup. the frame 50, intended to be hermetically covered by the teat 52. In the example of FIG. 6C, however, the lower part of the frame 50 comprises grooves 58, here four in number, intended to be hermetically covered through the teat 52. Here, each groove 60 opens out through a longitudinal slot in the duct connecting the outlets 54 and 56. Such grooves 60 have the advantage of promoting the deformation of the teat 52 when the space between the teat 52 and the frame 50 is placed in a vacuum. The frame 50 has here two outlets which are intended to be outside the bucket 22 when the core 24 is partially inserted into the cup 22. For example, an outlet makes it possible to connect the core 24 to a pressure source, ensuring the maintenance of the volume of the core 24. The other outlet can then allow the core to be connected. 24 to a source of vacuum, ensuring the contraction of the teat 52. In this case, as shown in the figures, the device 100 comprises six cores 24 which are each received in one of the six cups 22.

The device 100 further comprises a means 26 for deforming the cup 22 to extract a stick of cosmetic product from the cup without damaging it. In this case, the means 26 makes it possible to deform each of the six buckets 22. Each bucket 22 is of a size smaller than that of the cavity 20, so as to define a space E between each of the buckets 22 and the corresponding cavity 20. The means 26 makes it possible to depressurize the spaces E and thus deform each of the cups 22 and allow easy demolding without damaging the stick of cosmetic product 10, as illustrated in FIG. 7. The means 26 is of the known type and may include a vacuum pump, piping, and check valves.

The device 100 illustrated in the figures thus makes it possible to simultaneously produce six sticks of cosmetic product 10.

In the following, we describe more particularly the case of the production of a stick of cosmetic product 10 in a cup 22 by means of a core 24, it being understood that this description applies to each of the cups 22 arranged in the cavities 20 with each time a core 24.

To achieve a bevelled surface 10A of the heart 12 surrounded by sheath 14 at the level of the free end 10A, the core 24 is shaped to come into contact with the bottom of the cup 22. For this purpose, the core 24 has a bevelled free end 24A of equivalent shape to the bevelled free end 10A of the stick of cosmetic product 10. The interior of the cup 22 also has a corresponding bevelled internal surface 22A. Thus, when the core 24 is inserted into the cup 22, the free end 24A of the core 24 comes into contact with the bevelled internal surface 22A of the cup 22. This contact makes it possible to prevent the composition A intended to form the sheath 14 does not pass between the free end 24A of the core 24 and the bevelled internal surface 22A of the cup 22. In the absence of contact, the core 12 would not be visible at the level of the free end 10A in the stick of cosmetic product 10 because it would be completely covered by the sheath 12, at least before the first uses of the stick of cosmetic product 10.

Furthermore, in order to ensure a constant thickness 14 'of the sheath 14 around the core 12 at the level of the free end 10A, the core 24 is offset with respect to the longitudinal axis XX, as best seen at FIG. 5. For this purpose, an offset D can be provided between the longitudinal axis XX of the stick of cosmetic product 10, and the axis X12 of the core 12 of the stick of cosmetic product 10. The axis X12 of the core 12 is defined as being the median axis of the cylindrical part 12C of the heart 12 of the stick of cosmetic product 10. This axis X12 is therefore defined outside the zone of the oblique surface 10A of the stick of cosmetic product 10.

In the example illustrated, the cup 22 is elastic. [0057] The device 100 further comprises a pressure adjustment means

25 of the core 24 in the cup 22. This makes it possible to ensure contact between the free end 24A of the core 24 and the bevelled internal surface 22A of the cup 22 while preventing the cup 22 from deforming under too much pressure from the cup. core 24. For this purpose, the core 24 is slidably mounted on a block 28 by means of the pressure adjustment means 25. The pressure adjustment means 25 here comprises a bearing 30, a rod 32 and a spring 34. The spring 34 makes it possible to exert a pressure on the bearing 30 and thus to regulate the pressure exerted by core 24 on the bottom of the cup 22. The characteristics of the spring 34 are chosen according to the dimensions of the core 24 and of the bucket 22, and of the elasticity of the bucket 22. The elasticity of the spring 34 is adapted so that the movement of a finger 42 relative to the core 24 is stopped before the deformation of the core 24 while the movement of the block 28 continues its implementation race. Spring 34 is preferably a compression spring. The stroke of the core 24 is preferably less than 5 mm, for example equal to 2 mm. When the core 24 is properly seated in the cup 22, the pressure adjusting means 25 is preferably substantially at mid-stroke. Each core 24 is independent. Thus, with reference to FIG. 5, the two cores 24 illustrated are at different heights. In this case, a difference d, more or less large and possibly zero, is thus visible in FIG. 5 between the two cores 24 shown. This gap d is also present between the free ends 24A of the core 24 coming into contact with the bevelled internal surface 22A of the bucket 22. This gap d is also present at the level of the bearings 30. This difference in height is linked to the difference in compression. of the two springs 34. This difference d may be due, for example, to differences between the buckets 22, in particular because of their manufacturing tolerances.

The device further comprises a flange 38 and a reduction plate 40. As best seen in Figures 5, 7A, 7B and 8, the flange 38 is intended to remain on the base 18 to hold the cup 22, while that the reduction plate 40 is intended to be removed after making the stick of cosmetic product 10, to allow the latter to be attached to a dispensing mechanism 16, preferably before unmolding the stick of cosmetic product 10 from the cup 22.

The flange 38 is held at the base 18, for example by magnetization.

The reduction plate 40 can be arranged and centered on the flange 38 by a centering finger 42 fixed to the reduction plate 40. In this case, there are as many centering fingers 42 as there are cores 24 and buckets 22. In fact, as best seen in FIG. 5, the finger 42 is inserted through the flange 38 into the cup 22. The finger 42 is of course provided with a through opening 42 ' allowing the passage of the core 24 through the finger 42 and the filling with the composition A intended to form the sheath 14.

The reduction plate 40 can be held on the flange 38, for example by magnetization. In order to ensure the correct positioning of the core 24 in the bucket 22, the device 100 - in particular the block 28 - may further comprise a means 36 for guiding in translation and centering the core 24 in the bucket 22 .

The translational guide and centering means 36 comprises one or more rings 44 for translational guide and centering intended to be inserted into housings 46 provided on the flange 38. In this case, it can be provided two guide rings in translation and centering 44 intended to be inserted into two corresponding housings 46. These rings 44 allow the block 28 to be centered against the base 18, by means of the flange 38 and the reduction plate 40. The translational guide and centering rings 44 are inserted and adjusted in the housings 46 slightly frustoconical to facilitate guiding and centering. Ring 44 can be metal. The ring 44 can be fixed to the base 18 by means of the flange 38, by means of magnets 47 positioned on the flange 38, opposite the housings 46 of the reduction plate 40. The block 28 can then be held. firmly against the base 18.

The translational guide and centering means 36 can be retractable, thus allowing to retract between the inserted position (Figure 3B) and the withdrawn position (Figure 3A) of the core 24.

Furthermore, the rings 44 are magnetic so that the translational guide and centering means 36 can be maintained in the retracted position relative to the block 28 by means of magnets 48 provided on the block 28 and / or on the translational guide and centering means 36, as best seen in FIG. 4A.

When the core 24 moves from the withdrawn position to the inserted position, the block 28 is approached to the base 18, in this case the reduction plate 40, so that each core 24 is gradually inserted into the corresponding cup 22.

As soon as the rings 44 fit into the housing 46, the translational guide and centering means 36 being retracted beforehand, the core 24 has reached its position inserted in the cup 22 (FIG. 4A). To this end, the translational guide and centering means 36 may include a sliding assembly 38, more precisely a pair of sliding assemblies 38. Each sliding assembly 38 is formed of a sliding rod 38A mounted to slide in translation in a guide bearing 38C embedded in the block 28, via slides 38B, other bearings or ball cages, for example.

Referring to Figures 4A to 4C, the block 28 comprises a housing 38D in which the guide bearing 38C is embedded and relative to which the rod 38A is able to slide along the longitudinal axis X-X. Thus, the rod 38A can come to be retracted inside the block 28 by sliding.

Hereinafter, the steps of an example of a method of manufacturing a stick of cosmetic product are described. The means for supplying and pouring or injecting compositions A and B are not described below. Indeed, such means are well known to those skilled in the art. The method described below makes it possible to manufacture a stick of cosmetic product 10, in particular of lipstick, comprising two compositions A and B, extending along a longitudinal axis XX, but also a stick of product cosmetic, in particular lipstick, of the heart-sheath type. Hereinafter, the description is made of a method for making a cosmetic stick 10 of the core-sheath type. It should however be understood that the description is not limited to this type of cosmetic product stick, but can be applied to any type of cosmetic product stick comprising two compositions A and B, such as the first composition A s' spreads around the second composition B over at least a portion of the stick of cosmetic product 10. In a step E1, the translational guide and centering means 36 is retracted and the cores 24 are lubricated beforehand with a lubricating material making it possible to prevent compositions A and B from adhering thereto. For this purpose, the cores 24 are for example coated with silicone. In order to allow contact between the free end 24A of the core 24 and the bevelled internal surface 22A of the cup 22, provision may be made for the free end 24A of the core not to be covered with silicone. The coating can be carried out by spraying.

In a step E2, the reduction plate 40 and the centering fingers 42 which are fixed to it are placed on the flange 38, itself placed on the base 18.

In a step E3, the block 28 is brought above the base 18, in this case above the reduction plate 40, for example by means of a robotic arm (not shown).

In a step E4, the block 28 is then lowered along the longitudinal axis XX to approach the translational guide and centering means 36 of the base 28, in this case of the reduction plate 40, each core 24 gradually being inserted into the corresponding cup 22. The approximation of the block 28 stops when the translational guide and centering rings 44 of the translational guide and centering means 36 are in position in the housings 46.

The guide rings in translation and centering 44 fit snugly into the housing 46 and are held by magnetization against the flange 38, the block 28 then being held fixed against the base 18. Each core 24 is then in contact with the bevelled internal surface 22A of the cup 22 without deforming the latter, thanks to the corresponding pressure adjustment means 25. Each core 24 comes into contact with the bevelled internal surface 22A of the cup 22 before the end of the approximation of the block 28 (Figures 3B, 4A and 5). At this stage, the core 24 can be supplied with pressurized gas, to maintain the shape of the core 24. Once the core 24 has been placed inside the cup 22, that is to say in inserted position, we bring in a step E5, a filling head (not shown) facing the through opening 42 'provided in the cup 22. It is then poured or injected inside the cavity C, defined by the free volume between the core 24 and the cup 22, an amount of composition A corresponding substantially to the volume of said cavity C (FIG. 5). During this stage of casting or injection, the composition A penetrates inside the cavity C, expels the air initially present in the latter and comes into contact with the relief surface S 'of the core 24. Also during this step, the core 24 can be supplied with pressurized gas to ensure that the core retains its shape during this step. Optionally, there may be provided a step E6 of preheating or cooling the cup 22, carried out before the step of casting or injecting composition A.

A step E 7 of cooling and at least partial solidification of the composition A thus cast follows. After cooling and at least partially solidifying, the composition A poured inside the cavity C adheres to the cup 22, at its filling zone, by contact with the side wall and the bottom of the cup 22. It can be provided. that the emerging opening 42 'provided in the fingers 42 is slightly frustoconical, narrowing downwards from the stick of cosmetic product 10, that is to say towards the end 10B of the stick of cosmetic product 10. This makes it possible to reduce the diameter of the stick of cosmetic product 10 in order to adapt it to the dispensing mechanism 16. Also, this plays a role in the maintenance of the sheath 14 when the core 24 is withdrawn.

After at least partial cooling of the composition A, the part of the core 24 between the teat 52 and the frame 50 is placed in a vacuum during a step E8. This allows the core to be withdrawn from the cup 22, without damaging the casting or injected composition A. The block 28 is then reassembled along the longitudinal axis XX. The magnets 48 are then separated from the translational guide and centering means 36 which stretch progressively, the cores 24 still being in the buckets 22, until they are fully deployed, the cores 24 then being outside the buckets 22. The fully deployed position of the translational guide and centering means 36 is defined by a stop of the sliding assemblies 38. For this purpose, the device 100 may include screws 37, screwed to the translational guide and centering rings 44, which are able to slide in bores 37 'provided in the block 28 and come into abutment against a shoulder 37 ”provided in the bores 37'. When the screws 37 come into abutment in the bores 37 'against the shoulders 37 ”, as shown in FIG. 4B, the translational guide and centering rings 44 are still housed in the housings 46.

As illustrated in Figure 4C, while the block 28 continues to be moved apart, until the cores 24 have reached their withdrawn position, along the longitudinal axis XX of the base 18 (in l 'species of the reduction plate 10), the screws 37 being in abutment, the guide rings in translation and centering 44 are withdrawn from the housings 46 by means of the screws 37. It can be provided that the magnets 48 holding the retracted position have a lower magnetic force than the magnets 47 holding the ring 44 in the housing 46. The translational guide means and centering 36 allows a rectilinear extraction of the cores 24 to avoid damaging the sheath 14 until 'in the withdrawn position (Figures 3A, 4C and 7A).

Once the cores 24 are in the withdrawn position, the block 28 is moved away from the base 28 by displacement means, not shown. The aforementioned silicone coating is then repeated on the cores 24 (step E1). The translational guiding and centering means 36 is then retracted into the retracted position by retraction means (not shown).

When the core 24 is removed from the cup 22 (see FIG. 7A), it leaves room for a cavity C 'formed inside the sheath 14. This cavity C' has a through opening 14 ”which can then be filled with composition B.

Then, in step E9, a second filling head (not shown) is brought to face the through opening 14 ”and it is poured or injected inside the second cavity C ', an amount of composition B corresponding substantially to the volume of said second cavity C'. During this casting or injection step, the second composition B penetrates inside the second cavity C ’and adheres to the sheath 14 of composition A, at their contact interface (see Figure 7B).

Preferably, the second composition B, cast inside the sheath 14, has a melting point lower than or equal to that of the first composition A. In this way, it is avoided that the second composition cast at the inside of the sheath 14 does not melt the first composition A. In this case, the adhesion between the core 12 and the sheath 14 can be obtained by friction or chemical reaction, between the first and second compositions A and B, localized at the interface of the core 12 and of the cladding 14. [0109] Alternatively, provision can be made for the second composition B, cast inside the cladding 14, to have a melting temperature slightly higher than that of the first composition A. In this way, when the second composition B is poured inside the sheath 14, it locally melts the first composition A. In this case, the adhesion between the core 12 and the sheath 14 can be obtained at the interface of the core 12 and of the sheath 14, by melting / mixing, between the first and second compositions A and B.

A new step E10 of cooling and solidifying the second composition B cast follows. The second composition B poured inside the second cavity C ’, then adheres to the first composition A, poured during the first cycle. The first and second compositions A, B then form an integral whole, namely the stick of cosmetic product 10.

Before unmolding the stick of cosmetic product 10 from the cup 22, the reduction plate 40, and therefore the centering finger 42 fixed to the reduction plate 40, is removed in a step E11, to allow the stick to be fixed. of cosmetic product 10 to a dispensing mechanism 16, as illustrated in FIG. 8. The manipulation of the reduction plate 40 can be done by a robotic arm (not shown in the figures).

In order to be able to extract the stick of cosmetic product 10 from the cup 22 without damaging it, the means 26 for deforming the cup 22 is actuated to deform each of the six cups 22 (step E12), as illustrated in FIG. 8. Under the effect of the air suction, the space E present between the cup 22 and the cavity 20 is reduced to a space E 'and the cup 22 is deformed thanks to its elasticity under the effect of this. pressure. As soon as the cup 22 is deformed, it moves away from the sheath 14 and from the core 12, and the stick of cosmetic product 10 can be released from the mold without damaging the stick of cosmetic product 10.

After demoulding, the relief surface S forms a decorative relief pattern on the internal face of the sheath of the cosmetic product 10.

The production cycle composed of steps E1 to E12 described above can then resume at the start of the process.

A rotary plate machine can be used to implement this method, the bases 18 then moving from station to station for carrying out each step E1 to E12.

The invention is not limited to the only examples described above but is, on the contrary, susceptible to numerous variations accessible to those skilled in the art.

By relief, it is understood here that the decorative surface portion S is protruding or recessed, so as to form at least one undercut with respect to a release along the axis of the stick of cosmetic product 10. In the example illustrated, the core and the sheath have complementary reliefs. According to a variant not shown, the relief in the sheath is a hollow, opening onto the radially outer surface of the stick of cosmetic product, which is filled with a protruding relief of the composition forming the heart of the stick of cosmetic product. Other variations of the reliefs in the heart and sheath are accessible to those skilled in the art.

In the example illustrated, the outer surface of the stick of cosmetic product is devoid of a relief decoration zone. Alternatively, however, this external surface of the stick of cosmetic product can have a relief decoration zone. To do this, the cup 22 may have a protruding or recessed relief. In particular, each cup 22 may have a raised surface (not shown) which is complementary to a raised surface produced on the sheath 14. For example, when the raised surface of the stick of cosmetic product 10 protrudes, the surface in relief of the cup 22 is recessed. Conversely, when the relief surface of the stick of cosmetic product 10 is hollow, the relief surface of the cup 22 is protruding.

[0100] Furthermore, in the example illustrated, the cup 22 is flexible and deformable. However, the cup 22 can also be rigid, in particular when the stick of cosmetic product to be produced has no protruding or recessed relief on its external surface.

Claims

[Claim 1] A stick of a cosmetic product, in particular a lipstick, comprising first (A) and second (B) compositions extending along a longitudinal axis (XX) of the stick of cosmetic product such that the first composition (A) extends around the second composition (B) over at least a portion of the stick of cosmetic product, the first composition (A) being self-supporting, the internal surface of the first composition (A) having at least one relief.

[Claim 2] A cosmetic product stick according to claim 1, in which the first composition (A) is translucent or transparent, the second composition (B) preferably being colored.

[Claim 3] A cosmetic stick according to claim 1 or 2, wherein the second composition (B) is self-supporting.

[Claim 4] A cosmetic product stick according to claim 3, in which the external surface of the second composition (B) has at least one relief complementary to the at least one relief of the internal surface of the first composition (A).

[Claim 5] A cosmetic stick according to claim 1 or 2, wherein the second composition (B) is a viscous liquid or gel.

[Claim 6] A cosmetic product stick according to any preceding claim, in which the cosmetic product stick is of the core-sheath type, the first (A) and second (B) compositions being arranged with respect to one another. the other to form a heart (12) surrounded by a sheath (14) along the longitudinal axis (XX), the sheath (14) having an internal lateral surface having said at least one relief.

[Claim 7] A cosmetic stick according to any preceding claim having a bevelled free end (10A).

[Claim 8] A stick of cosmetic product according to claims 6 and 7, in which the sheath (14) has at the level of the bevelled free end (10A) a thickness (14 ') which is constant around the core (12).

[Claim 9] A cosmetic stick according to claim 8, wherein at the bevelled free end (10A), the core (12) is concentric with the sheath (14).

[Claim 10] A cosmetic product stick according to any one of the preceding claims, in which the at least one relief on the radially internal surface of the first composition (A) is protruding towards the second composition (B) or recessed in the first composition (A).

[Claim 11] A cosmetic product stick according to any one of the preceding claims, in which the at least one relief on the radially inner surface of the first composition (A) comprises a hole radially passing through the first composition (A), the second composition (B) preferably extending through the hole to the radially outer surface of the first composition (A).

[Claim 12] A method of manufacturing a stick of cosmetic product, in particular lipstick, comprising a first composition (A) and a second composition (B), the first and second compositions (A, B) extending from along a longitudinal axis (XX) of the stick of cosmetic product, such that the first composition (A) extends around the second composition (B) on at least one portion of the stick of cosmetic product, the first composition (A) being self-supporting, the internal surface of the first composition (A) having at least one relief, the process comprising:

- the installation of a deformable core (24) in a cup (22), the core having a substantially cylindrical or frustoconical surface with at least one relief,

- molding, in particular by casting or injection, of a first composition (A) between the core (24) and the cup (22) to form a first element (14),

- the withdrawal of the core (24) from the bucket (22),

- casting or injecting a second composition (B) to form a second element (12) at least partially inside the first element (14), thus forming a stick of cosmetic product (10), and

- a step (E12) consisting in unmolding the stick of cosmetic product (10) from the cup (22).

[Claim 13] A method of manufacturing a cosmetic stick according to claim 12, comprising lubricating the core (24).

[Claim 14] A method of manufacturing a cosmetic stick according to claim 12 or 13, in which the withdrawal of the core (24) from the cup is carried out after having deformed the core (24), in particular contracted the core (24). ).

[Claim 15] Device for manufacturing a stick of cosmetic product, in particular lipstick, comprising first (A) and second (B) compositions extending along a longitudinal axis (XX) of the stick of product cosmetic such that the first composition (A) extends around the second composition (B) over at least one portion of the stick of cosmetic product, the first composition (A) being self-supporting, the internal surface of the first composition (A) having at least one relief, the device comprising:

- a base (18) comprising a cavity (20) formed in the base (18),

- a cup (22) received in the cavity (20),

- a core (24) movable in translation between an inserted position in which the core (24) is positioned in the cup (22), the core (24) coming into contact with the bottom of the cup (22), and a withdrawn position wherein the core (24) is withdrawn from the cup (22), the core (24) being deformable, the core (24) having a substantially cylindrical or frustoconical shape with at least one relief on its side surface, and

- a means for deforming the core (24) so that the core (24) can be extracted from the cup (22) after having molded the first composition (A) in the space between the cup (22) and the core (24).

[Claim 16] A device according to claim 15, wherein:

- the cup (22) is smaller than that of the cavity (20) so as to define a space (E) between the cup (22) and the cavity (20), and

- the bucket (22) comprises a means (26) for depressurizing the space (E).

[Claim 17] A device according to claim 15 or 16, wherein the core (24) comprises a deformable nipple, defining a sealed internal space, and a channel, said channel placing said fluid in communication with said. internal space and a device for pressurizing and / or reducing the closed internal space.

[Claim 18] Device according to any one of claims 15 to 17, further comprising means (25) for adjusting the pressure exerted by the core (24) on the bottom of the bucket (22).

[Claim 19] Device according to the preceding claim, wherein the pressure adjusting means (25) comprises a spring (34).

[Claim 20] Device according to any one of claims 15 to 19, further comprising a translational guide and centering means (36) of the core (24) in the bucket (22).

[Claim 21] Device according to the preceding claim, wherein the translational guide and centering means (36) is retractable.

[Claim 22] Device according to claim 21, further comprising magnetization means (48) making it possible to maintain the translational guide and centering means (36) in the retracted position.

[Claim 23] Device according to one of claims 20 to 22, in which the core (24) and the translational guide and centering means (36) are mounted on a block (28).

[Claim 24] Device according to any one of claims 20 to 23, wherein the translational guide and centering means (36) comprises a centering ring (44) adapted to cooperate with a housing (46) provided in the base (18).

[Claim 25] A device according to any one of claims 15 to 24, comprising a plurality of cavities (20), a plurality of cups (22) and a plurality of cores (24), each core (24) having a substantially shape. cylindrical or frustoconical with at least one relief on its side surface, wherein the plurality of cavities (20) is formed in the base (18), wherein each of the cups (22) is received in a respective cavity (20), and in which each of the cores (24) is movable in translation between an inserted position in which the core (24) is positioned in a cup (22) and a withdrawn position in which the core (24) is removed from the cup (22).