FR2979206A1 - METHOD FOR MANUFACTURING A COSMETIC PRODUCT APPLICATOR, USE AND SERIES OF COSMETIC PRODUCT APPLICATORS THEREFOR - Google Patents

Abstract

This method comprises providing an insert (16) and attaching a flexible tip to the insert (16). The fixing step includes pouring a product to form a foam on the insert (16) and cross-linking the product to form a foam on the insert (16) to form a foam block.

Description

The present invention relates to a method for manufacturing a cosmetic product applicator, the method comprising the following steps: - supply of a cosmetic product applicator an insert ; - Attaching a soft foam tip on the insert. For the purposes of the present invention, the term "cosmetic product" is intended to mean a product as defined in Regulation (EC) No. 1223/2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products.

The cosmetic product is for example a composition to be applied to a keratinous surface of a user, such as the nails, the skin, including the skin of the eyelids, or the lips. The aforementioned method is intended to be used to manufacture cosmetic product applicators comprising a rod-shaped insert, and a deformable tip attached to the insert. FR 2 948 542 describes an example of an applicator of this type. To manufacture the applicator, it is known to provide an insert, for example plastic or metal. Then, the tip is manufactured separately in a deformable plastic material, for example by molding. The tip is then assembled hot or cold on the rod.

In the state of the art, the insert is glued or nested with the foam. The resistance between the foam and the insert is low (approximately 400 g). In some cases, the tip is not fixed sufficiently robustly on the insert, so that it is likely to detach later, especially during use.

To overcome this problem, FR 2 948 542 also suggests forming the tip by overmoulding on the insert, to reduce the clearance between the insert and the tip. Such a method does not give complete satisfaction in a mass production. In particular, overmolding each endpiece requires properly positioning each insert and injecting each end into a suitable mold, which can be long and tedious to implement. FR 2 894 791, FR 2 888 734, US 2005/0097693, EP 875 169, WO 2009/019393 and FR 2 762 494 also describe processes for manufacturing cosmetic product applicators.

An object of the invention is to obtain a method of manufacturing cosmetic product applicators, in which a tip is fixed in a particularly robust manner on an insert, the method being however very economical to implement. For this purpose, the subject of the invention is a process of the aforementioned type, characterized in that the fixing step comprises the following phases: casting a product intended to form a foam on the insert; crosslinking the product intended to form a foam on the insert to form a block of foam. The method according to the invention may comprise one or more of the following characteristics, taken separately or in any technically possible combination: it comprises the supply of a plurality of inserts, the fixing step comprising the phases following: - overmoulding of the plurality of inserts by a continuous block of foam connecting the inserts together; cutting the continuous block to separate the block into a plurality of individual foam blocks each receiving an insert; forming a tip on each insert from the individual block overmolding said insert; after the cutting phase, each individual block overmoulds a single insert, the tip being formed on each insert from the individual block attached to said insert, the step of forming the tip comprises machining the foam block fixed on the insert, after crosslinking; the insert comprises an elongated element and a retaining element, in particular a projection, a groove or a hole, the fixing step comprising casting the product on or in the retaining element; the elongated element extends along a longitudinal axis, the retaining element having a transverse surface with respect to the elongated element, the casting phase comprising the product arrangement intended to form a foam facing the transverse surface; to cover the transverse surface; the foam forming the flexible tip is an elastomeric foam, advantageously chosen from polyurethane, NBR, SBR, PE or mixtures thereof, and the insert is made from a material that is more rigid than the tip; flexible, especially based on a plastic material, a thermoplastic material, a thermosetting material, a metal, wood, or a foam.

The subject of the invention is also a use of an applicator manufactured by the method described above for the production of a cosmetic product conditioning device comprising a cosmetic product reservoir, the applicator being intended for taking the cosmetic product present in the cosmetic product container. The reservoir.

The invention also relates to a cosmetic product applicator, comprising an insert and a flexible foam tip, characterized in that the flexible tip is attached to the insert by crosslinking. The applicator may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination: the flexible tip defines at least one outer surface obtained by cutting a continuous block of material, and the insert comprises an elongate element and a retaining element, in particular a radial projection with respect to the elongate element, a groove or an orifice, the flexible endpiece overmolding the retaining element.

The invention also relates to a series of cosmetic product applicators, each applicator of the series being as described above. The series may comprise the following characteristic: the flexible tip of each applicator defines at least one outer surface obtained by cutting a continuous block of material overmolding several inserts.

The invention will be better understood on reading the description which follows, given solely by way of example, and with reference to the appended drawings, in which: FIG. 1 is a view taken in section along an axial plane a first cosmetic product applicator manufactured by a first method according to the invention; FIG. 2 is a schematic side view of an example of a cosmetic product conditioning device comprising the applicator of FIG. 1; FIG. 3 is a functional block diagram of the various steps of the first manufacturing method according to the invention; - Figure 4 is a sectional view along a median plane of a mold for the implementation of a first phase of the process illustrated in Figure 3; - Figure 5 is a sectional view along a median axial plane of a common block of flexible material overmolding a plurality of inserts during a vulcanization phase of the block; and - Figure 6 is a view similar to Figure 5 during a machining phase of a portion of the block; - Figures 7 to 9 illustrate alternative applicators according to the invention; - Figure 10 illustrates a cluster of inserts; - Figure 11 illustrates an applicator variant according to the invention; - Figure 12 illustrates another variant of the applicator according to the invention; 13 is a view similar to FIG. 4 of another mold intended to implement a first phase of the method illustrated in FIG. 3. In the following, the terms "distal" and "proximal" are given in FIG. Are generally understood as respectively closer, and farther away from the member of a user grabbing an applicator. Figures 1 and 2 illustrate a first applicator 10 of cosmetic product manufactured by a method according to the invention. The applicator 10 is intended in particular to be implemented within a cosmetic product conditioning device 12, an example of which is shown diagrammatically in FIG. 2. The cosmetic product intended to be applied by the applicator 10 is for example a cosmetic product in the form of a liquid, a cream, a gel, a dispersed solid such as a powder or a block of solid. The cosmetic product is for example a composition intended to be applied to a keratinous surface of a user such as the nails, the skin, including that of the eyelids, or the lips. The applicator 10 is particularly suitable for applying products used for makeup eyelashes, eyebrows or eyelids, or for the application of product on the nails of a user. In particular, these applicators may be makeup applicators such as nail polish, gloss, mascara, eyeshadow, foundation, etc. They may also be intended for applying skin care products or hair products. In addition to the applicator 10, the device 12 generally comprises a reservoir 14 of cosmetic product visible in FIG. 2. The applicator 10 is intended to be dipped in the cosmetic product present in the reservoir 14, then to be extracted from the reservoir 14 for be brought into contact with the user's keratinous surface.

As illustrated in FIGS. 1 and 2, each applicator 10 obtained by the method according to the invention comprises an insert 16 in the general shape of a rod, and a tip 18 of foam attached to the insert 16 by crosslinking a product intended for form a foam. Advantageously, the applicator 10 further comprises a gripping member 20 disposed at a proximal end of the insert 16.

The gripping member 20 advantageously forms a shutter member of the reservoir 14 when it is present.

As illustrated by FIGS. 1 and 2, the insert 16 comprises an elongated element 24 in the form of a rod, and a retaining element formed here by a head 26 for fixing the endpiece 18. The head 26 is disposed in this for example, at the distal end of the elongated element 24.

Advantageously, the fastening head 26 and the elongated element 24 are integral. The insert 16 is for example made of a thermoplastic material, thermosetting, a metal, wood or a foam, in particular a foam of composition distinct from the foam of the tip.

The elongate member 24 extends substantially along a local axis A-A 'shown vertical in Figure 1. The elongate member 24 is flexible to be flexibly deformable between the fingers of a user. It is for example attached to the gripping member 20, or to a tubular element secured to the gripping member 20.

The fixation head 26 has an elongated distal portion 28 and a proximal retaining portion 30 of the tip 18. The distal portion 28 has a shape converging towards the distal end of the applicator 10, opposite the elongated element 24. It extends here substantially in the axial extension of the elongated element 24 along the axis A-A '.

In this example, the proximal retaining portion 30 protrudes transversely of the distal portion 28 and the distal end of the elongate member 24. It defines at least one proximal transverse surface 32 oriented toward the elongated member 24 and at least one distal transverse surface 34. As will be seen below, the surfaces 32, 34 are completely covered by the tip 18. In this example, the proximal transverse surface 32 has a region adjacent to the elongate member 24 which extends substantially in a plane perpendicular to the axis A-A '. The surfaces 32, 34 thus define respectively with the peripheral surface of the elongated element 24 and with the outer surface of the distal portion 28 of the proximal and distal shoulders adapted to retain axially the nozzle 18 with respect to the insert 16 according to FIG. axis A-A '. In the example shown in Figure 2, and in at least one axial plane passing through the axis A-A ', the attachment head 26 of the insert 16 has a general shape of three leaf clover.

The proximal portion 30 is annular. It extends angularly continuously around the axis A-A '. In a variant (not shown), the proximal portion 30 is formed by a plurality of disjointed transverse regions separated from each other by gaps.

The tip 18 completely covers the head 26 and partially the distal end of the elongated element 24. It is overmolded on the insert 16 being fixed by crosslinking on the insert 16. Thus, the tip 18 is applied to the insert 16, over the entire outer surface of the head 26. The tip 18 comprises a tip body 40 made of a softer material than the insert 16. The body 40 is formed for example from an elastomer , in particular starting from a flexible foam such as a polyurethane foam, a foam of NBR (Nitrile Butadiene Rubber) or a foam of SBR (Styrene Butadiene Rubber), a PE foam (Polyethylene) or advantageously their mixtures, especially a mixture of SBR and NBR. The body 40 of the tip 18 is formed from a porous material capable of receiving and retaining cosmetic product in its pores and / or interstices. According to the invention, the body 40 delimits an outer surface 42 obtained by cutting and machining a block of material molded onto the insert 16.

In this example, the surface 42 has been machined to converge while moving away from the elongate member 24 along the axis A-A '. It thus has a general shape of tip covering the fixing head 26 and the distal end of the elongated element 24. According to the invention, the endpiece 18 receives the attachment head 26 and the distal end of the element elongate 24 in a cavity of corresponding shape. In particular, the tip 40 delimits a proximal collar 44 applied around the distal end of the elongated element 24 and applied on the proximal transverse surface 32 to ensure effective axial locking of the tip 18 on the insert 16. In variants shown in Figures 7 to 9 and 11 to 12, the insert 16 is devoid of projecting head 26. The retaining element of the nozzle 18 is formed by at least one through opening 35A (see FIGS. 7, 8, 11 and 12) or by a groove 35B, for example a dovetail. The tip 18 then partially covers the insert in the vicinity of the retaining element and enters the through opening 35A or the groove 35B forming the retaining element.

A method of manufacturing at least one applicator 10, and advantageously a series of applicators 10 according to the invention is implemented in an installation illustrated schematically in Figures 4, 5 and 6. This installation comprises a mold 50 for producing a foam block overmoulding at least one insert 16 (FIG. 4), a device 52 for crosslinking the foam block (FIG. 5). It further comprises an optional device (not shown) for cutting the foam block into several parts, in the case where several inserts 16 are received in the foam block. Referring to Figure 6, the installation further comprises an optional device 54 for machining each individual block of foam mounted on an insert to form a tip 18. As shown in Figure 4, the mold 50 has a first wall 60A, a second wall 60B delimiting with the first wall 60A a molding cavity 62, and means 64 for injecting a fluid material able to solidify in the cavity 62.

The first wall 60A delimits at least one orifice 66 for introducing an elongated element 24. The orifice 66 opens into the cavity 62. The second wall 60B extends facing the first wall 60. The cross-linking device 52 is capable of crosslinking, for example vulcanizing the block formed in the mold 50. It comprises for example means for emitting light radiation, electromagnetic radiation or heating means, such as an oven . The machining device 54 comprises for example a milling cutter or a rotary grinding wheel. The manufacturing method according to the invention will now be described, with reference to FIG.

This method comprises a step 110 for supplying at least one insert 16, advantageously a plurality of inserts 16 and a step 112 for forming a tip 18 on each insert 16. The step 112 comprises a phase 114 of provision or each insert 16 in the mold 50, a casting phase 116 of a block of flexible material on the or each insert 16 and a phase of crosslinking of the block. Step 112 further comprises an optional phase 120 (for example mechanical, laser, water jet) of the common block in several parts and an optional phase 122 for machining each part cut from the block for form a tip 18.

Initially, in step 110, at least one insert 16, advantageously a plurality of inserts 16 as described above are provided. These inserts 16 are for example provided separately or in the form of a cluster of inserts 16 interconnected by breakable parts 123 (see Figure 16). During phase 114, with reference to FIG. 4, each insert 16 is introduced into an orifice 66 formed in the first wall 60A of the mold. The elongated element 24 is received in the wall 60A, with the exception of a distal section 124 projecting into the molding cavity 62. The retaining element (here the head 26) also projects into the molding cavity 62. It is located away from the first wall 60A and away from the second wall 60B. The number of inserts 16 introduced simultaneously into the cavity is greater than or equal to 1, and is in particular greater than 10 or even 50. In addition, an empty intermediate space 126 extends between each insert 16, and in particular between the segments. distal 126 facing each insert 16. Then, during the phase 116, a fluid material for forming a foam is introduced into the molding cavity 62. This material is in particular a foaming material or a previously foamed material by mechanical stirring, for example by threshing. The material thus introduced fills the cavity 62. It is intended to form a continuous common block 128 of flexible material over-molding an individual insert 16 or a plurality of inserts 26. The block 128 is partially visible in FIG. 5. The continuous block 128 has a shape substantially complementary to that of the cavity 62. In the case where the block covers several inserts 16, the block 128 has a width greater than the width of two inserts 26 and a height greater than the height of the head 26 of the insert 16. Each insert retainer 16 is fully embedded in the continuous block 128. In addition, the proximal section 124 of each insert 16 is surrounded by material forming the continuous block 128. In the step 118, in FIG. 5, the continuous block 128 is placed facing the device 52 to be subjected to crosslinking, for example by vulcanization. This crosslinking makes it possible in particular to create covalent chemical bonds between the molecules forming the material constituting the continuous block 128. It also makes it possible to ensure the connection between the block 128 and each insert 16. The block 128 overmolding each insert 16 is then extracted Out of the molding cavity 62. Then, at step 120 when multiple inserts 16 are received in the same block 128, the continuous block 128 is cut into a plurality of individual blocks 130A-130E.

Each individual block 130A to 130E contains at least one insert 26.

This cutting is for example carried out using a cutting member, or with the aid of another cutting device such as a laser device. In particular, the cut is made parallel to the axis A-A 'of each insert 16, in the intermediate space 126 between two parallel inserts 16.

In the example shown in FIG. 5, each individual block 130A to 130E contains a single insert 16 after cutting. In this example, each individual block 130A to 130E advantageously also has a substantially parallelepiped shape, for example a cube shape.

As a variant, each individual block 130A to 130E has another shape, for example a cylindrical shape of axis A-A '. Then, during the phase 122, each individual block 130A to 130E is machined using the machining device 54 to adapt the shape of the outer surface of the block 130A to 130E to the outer surface 42 desired for the endpiece 18 .

During this machining, a flange 44 of material is held in contact with the proximal transverse surface 32, and around the distal portion 124 of the elongated element 24. As illustrated in FIG. 2, the applicators 10 thus formed can then be used for producing a cosmetic product packaging device 12 comprising, for example, a reservoir 14.

The method which has just been described thus makes it possible to obtain a large quantity of applicators 10 of various shapes, in which the tip 18 of the applicator is fixed in a very robust manner on the insert 16 carrying it by the crosslinking. material for forming the foam. These applicators 10 are obtained at low cost, in particular taking into account the possibility of overmolding simultaneously a large number of inserts 16 by a common block 128 of flexible material, then cutting the block 128 into several individual blocks 130A to 130E, so that forming a tip 18 on each insert 16. The method is therefore particularly economical to implement and simplifies the manufacture of applicators 10.

In a variant, the machining phase 122 is omitted. The end pieces 18 are formed directly by the cutting of the continuous block 128 into a plurality of individual blocks 130A to 130E, each part containing an insert 16. In a variant, a single applicator 10 is made at the same time by casting a single block containing a single insert 16 and then by crosslinking, without cutting the block.

In another variant (FIG. 11), at least two inserts 16 are assembled together by gluing, after the attachment of a tip 18 on each insert 16, for example by an adherent part 200, the applicator can then form a roll or a sphere. In another variant, visible in Figure 12, the insert 16 is an axis of rotation having through openings 35A. The applicator then forms a roll. In another variant, shown in Figure 16, the inserts are placed against a wall 60A of the mold without being introduced into the orifices. The wall 60A is then devoid of orifice. The inserts 16 are advantageously locked on projections 300 formed on the wall 60A. The term "one" must be understood as "at least one", unless the opposite is specified.

Claims (14)

1. A method of manufacturing an applicator (10) of cosmetic product, the method comprising the following steps: - providing an insert (16); - Attaching a flexible tip (18) foam on the insert (16); characterized in that the fixing step comprises the following steps: - casting a product for forming a foam on the insert (16); crosslinking the product intended to form a foam on the insert (16) to form a block of foam. 2.- Method according to claim 1, characterized in that it comprises the supply of a plurality of inserts (16), the fixing step comprising the following phases: - overmoulding of the plurality of inserts (16) by a continuous foam block (128) connecting the inserts (16) to each other; - cutting the continuous block (128) to separate the block (128) into a plurality of individual foam blocks (130A to 130E) each receiving an insert (16); forming a tip (18) on each insert (16) from the individual block (130A to 130E) overmolding said insert (16) 3. A method according to claim 2, characterized in that after the cutting step, each individual block (130A to 130E) overmold a single insert (16), the tip (18) being formed on each insert (16) from the individual block (130A to 130E) attached to said insert (16). 4.- Method according to any one of the preceding claims, characterized in that it comprises machining the foam block attached to the insert (16), after crosslinking. 5.- Method according to any one of the preceding claims, characterized in that the insert (16) comprises an elongate member (24) and a retaining element, in particular a projection, a groove or a hole, the step of fastener comprising pouring the product onto or into the retainer. 6. A process according to claim 5, characterized in that the elongated element (24) extends along a longitudinal axis (A-A '), the retaining element having a transverse surface relative to the elongate element. (24), the casting phase comprising the product disposition for forming a foam facing the transverse surface (32) to cover the transverse surface (32). 7. A process according to any one of the preceding claims, characterized in that the foam forming the flexible tip (18) is an elastomeric foam, preferably selected from polyurethane, NBR, SBR, PE or mixtures thereof. 8.- Method according to any one of the preceding claims, characterized in that the insert (16) is made of a more rigid material than the flexible tip (18), in particular based on a plastic material , a thermoplastic material, a thermosetting material, a metal, wood, or a foam. 9.- Use of an applicator (10) manufactured by the process according to any one of the preceding claims for producing a device (12) for packaging a cosmetic product comprising a reservoir (14) of cosmetic product, applicator (10) being intended to take the cosmetic product present in the reservoir (14). 10. Applicator (10) of cosmetic product, comprising an insert and a flexible foam tip; characterized in that the flexible tip (18) is attached to the insert (16) by crosslinking. 11- Applicator (10) according to claim 10, characterized in that the flexible tip (18) defines at least one outer surface (42) obtained by cutting a continuous block of material. 12. Applicator according to one of claims 10 or 11, characterized in that the insert (16) comprises an elongated element (24) and a retaining element (26), in particular a radial projection relative to the an elongate member (24), a groove or an orifice, the flexible tip (18) overmolding the retaining member. 13.- series of applicators (10) of cosmetic product, each applicator (10) of the series being according to any one of claims 10 to 12. 14.- Series according to claim 13, characterized in that the flexible tip (18) of each applicator (10) defines at least one outer surface obtained by cutting a continuous block of material overmolding several inserts (16).