WO2013026853A1

WO2013026853A1 - Method for manufacturing a cosmetic product applicator, associated use and series of cosmetic product applicators

Info

Publication number: WO2013026853A1
Application number: PCT/EP2012/066287
Authority: WO
Inventors: Denis Befve; Eric Caulier; Rodolphe Da Rovare
Original assignee: L'oreal
Priority date: 2011-08-25
Filing date: 2012-08-21
Publication date: 2013-02-28
Also published as: FR2979206A1; FR2979206B1

Abstract

This method comprises the supply of an insert (16) and the attaching of a flexible tip onto the insert (16). The step of attaching includes the pouring of a product intended to form a foam on the insert (16) and the cross-linking of the product intended to form a foam on the insert (16) in order to forma a foam block.

Description

Method for manufacturing a cosmetic product applicator, associated use and series of cosmetic product applicators

This invention relates to a method for manufacturing a cosmetic product applicator, the method comprising the following steps:

- supply of an insert;

- attaching of a flexible foam tip onto the insert.

"Cosmetic product" means in particular, in the sense of this invention, a product such as defined in Regulation (EC) no. 1223/2009 of the European Parliament and of the Council of 30 November 2009 relating to cosmetic products.

The cosmetic product is for example a composition to be applied to a keratinous surface of a user, such as nails, skin, including the skin of the eyelids, or lips.

The aforementioned method is intended to be implemented to manufacture cosmetic product applicators comprising an insert in the shape of a rod, and a deformable tip fixed on the insert.

FR 2 948 542 describes an example applicator of this type. In order to manufacture the applicator, it is known to supply an insert, for example made of plastic material or of metal. Then, the tip is manufactured separately from a deformable plastic material, for example by molding. The tip is then hot or cold assembled on the rod.

In the prior art, the insert is glued or nested with the foam. The stability between the foam and the insert is weak (approximately 400 g).

In certain cases, the tip is therefore not fixed in a sufficiently robust manner on the insert, in such a way that it is able to separate later, in particular during use.

To overcome this problem, FR 2 948 542 also suggests forming the tip by insert molding on the insert, in order to reduce the clearance between the insert and the tip.

Such a method however is not completely satisfactory in mass production.

In particular, insert molding of each tip requires correctly positioning each insert and injecting each tip 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 methods for manufacturing cosmetic product applicators.

A purpose of the invention is to obtain a method for producing cosmetic product applicators, wherein a tip is fixed in a particularly robust manner on an insert, the method however being very economical to implement.

For this purpose, the invention relates to a method of the aforementioned type, characterized in that the step of attaching comprises the following phases:

- pouring of a product intended to form a foam on the insert; - cross-linking of the product intended to form a foam on the insert in order to form a foam block.

The method according to the invention may comprise one or several of the following characteristics taken in isolation or in any technically possible combination:

- it comprises the supply of a plurality of inserts, with the step of attaching comprising the following phases:

- insert molding of the plurality of inserts by a continuous foam block connecting the inserts together;

- cutting of the continuous block in order to separate the block into a plurality of individual foam blocks each receiving an insert;

- forming of a tip on each insert using the individual block insert molding said insert;

- after the cutting phase, each individual block insert molds a single insert, with the tip being formed on each insert using an individual block attached to said insert,

- the step of forming of the tip comprises the machining of the foam block fixed on the insert, after cross-linking;

- the insert comprises an extended element and a retaining element, in particular a projection, a groove or a hole, the step of attaching comprising the pouring of the product on or in the retaining element;

- the extended element extends along a longitudinal axis, the retaining element comprising a transverse surface relative to the extended element, with the phase of pouring comprising the arrangement of product intended to form a foam facing the transverse surface to cover the transverse surface;

- the foam forming the flexible tip is an elastomer 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 flexible tip, in particular a plastic material, a thermoplastic material, a thermosetting material, metal, wood, or a foam.

Another purpose of the invention is the use of an applicator manufactured by the method described above for the creation of a cosmetic product packaging device comprising a reservoir of cosmetic product, the applicator being intended to draw the cosmetic product present in the reservoir.

Another purpose of the invention is a cosmetic product applicator, comprising an insert and a flexible foam tip, characterized in that the flexible tip is mounted on the insert via cross-linking. The applicator may comprise one or several 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 extended element and a retaining element, in particular a radial protrusion relative to the extended element, a groove or an orifice, with the flexible tip insert molding the retaining element.

The invention also relates to a series of cosmetic product applicators, with each applicator in the series being as described above.

The series may have the following characteristic:

- the flexible tip of each applicator defines at least one outer surface obtained by cutting a continuous block of material insert molding several inserts.

The invention will be better understood after reading the following description given solely as an example with reference to the appended drawings in which:

- Figure 1 is a sectional view along an axial plane of a first cosmetic product applicator manufactured by a first method according to the invention;

- Figure 2 is a diagrammatic side view of an example of a cosmetic product packaging device comprising the applicator in Figure 1 ;

- Figure 3 is a functional block diagram of the various steps of the first method for manufacturing according to the invention;

- Figure 4 is a sectional view along a median plane of a mold intended for the implementation of a first phase of the method shown in Figure 3;

- Figure 5 is a sectional view along an axial median plane of a common block of flexible material insert molding a plurality of inserts, during a vulcanizing 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 show the variants of applicators according to the invention;

- Figure 10 shows a cluster of inserts;

- Figure 1 1 shows a variant of the applicator according to the invention;

- Figure 12 shows a another variant of the applicator according to the invention;

- Figure 13 is a view similar to Figure 4 of another mold intended for the implementation of a first phase of the method shown in Figure 3.

In all of what follows, the terms "distal" and "proximal" generally mean respectively closer to, and further from the limb of a user grasping an applicator. Figures 1 and 2 show a first cosmetic product applicator 10 manufactured by a method according to the invention.

The applicator 10 is intended in particular to be implemented in a cosmetic product packaging device 12, of which an example is shown diagrammatically in Figure 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 nails, skin, including that of the eyelids, or the lips. The applicator 10 is in particular suitable for applying products used for makeup of the eyelashes, eyebrows or eyelids, or for the application of product on the nails of a user. In particular, these applicators may be applicators of makeup such as nail varnish, gloss, mascara, eye shadow, foundation, etc.

They may also be intended to apply skin care products or hair care products.

In addition to the applicator 10, the device 12 generally comprises a cosmetic product reservoir 14 visible in Figure 2. The applicator 10 is intended to be soaked in the cosmetic product present in the reservoir 14, then to be extracted from the reservoir 14 in order to be brought into contact with the keratinous surface of the user.

As shown in Figures 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 foam tip 18 mounted on the insert 16 by cross-linking of a product intended to form a foam.

Advantageously, the applicator 10 further comprises a gripping element 20 arranged at a proximal end of the insert 16.

The gripping element 20 advantageously forms a closing part of the reservoir 14, when the latter is present.

As shown in Figures 1 and 2, the insert 16 comprises an extended element 24 in the shape of a rod, and a retaining element formed here by a head 26 for attaching the tip 18. The head 26 is arranged, in this example, at the distal end of the extended element 24.

Advantageously, the head for attaching 26 and the extended element 24 form a single piece.

The insert 16 is for example made from a thermoplastic, thermosetting material, a metal, wood or a foam, in particular a foam of composition separate from the foam of the tip.

The extended element 24 extends substantially along an local axis A-A' shown as being vertical in Figure 1 . The extended element 24 is flexible in order to be deformed by bending between the fingers of a user. It is for example mounted on the gripping element 20, or on a tubular element fixed to the gripping element 20.

The head for attaching 26 comprises an extended distal portion 28 and a proximal portion 30 for retaining the tip 18.

The distal portion 28 has a shape that converges towards the distal end of the applicator 10, opposite the extended element 24. It extends here substantially in the axial extension of the extended element 24 along the axis A-A'.

In this example, the proximal retaining portion 30 protrudes transversally relative to the distal portion 28 and relative to the distal end of the extended element 24. It defines at least one transverse proximal surface 32 facing the extended element 24 and at least one distal transverse surface 34.

As we will see later, the surfaces 32, 34 are entirely covered by the tip 18.

In this example, the proximal transverse surface 32 has a region adjacent to the extended element 24 which extends substantially in a plane perpendicular to the axis A- A'.

The surfaces 32, 34 as such define respectively with the peripheral surface of the extended element 24 and with the outer surface of the distal portion 28 of the proximal and distal shoulders able to axially retain the tip 18 relative to the insert 16 along the axis A-A'.

In the example shown in Figure 2, and in at least one axial plane passing through the axis A-A', the head for attaching 26 of the insert 16 has the general shape of a three- leafed 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 separated transverse regions separated from each other by spaces.

The tip 18 entirely covers the head 26 and partially the distal end of the extended element 24.

It is insert molded on the insert 16 and is attached by cross-linking on this insert

16. As such, the tip 18 is applied onto the insert 16, over the entire outer surface of the head 26.

The tip 18 comprises a tip body 40 made from a more flexible material than the insert 16.

The body 40 is for example formed using an elastomer, in particular using a flexible foam such as a polyurethane foam, an NBR (Nitrile Butadiene Rubber) foam or an SBR (Styrene Butadiene Rubber) foam, a PE (Polyethylene) foam or advantageously mixtures thereof, in particular a mixture of SBR and NBR.

The body 40 of the tip 18 is formed from a porous material that can receive and retain the 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 insert molded on the insert 16.

In this example, the surface 42 was machined in order to converge by displacing away from the extended element 24 along the axis A-A'. It thus has the general shape of a point covering the head for attaching 26 and the distal end of the extended element 24.

According to the invention, the tip 18 receives the head for attaching 26 and the distal end of the extended element 24 in a cavity of corresponding shape. In particular, the tip 40 delimits a proximal flange 44 applied around the distal end of the extended element

24 and applied on the proximal transverse surface 32 in order to provide an effective axial blocking of the tip 18 on the insert 16.

In the variants shown in Figures 7 to 9 and 1 1 to 12, the insert 16 does not have a projecting head 26.

The retaining element of the tip 18 is formed by at least one through opening 35A (see Figures 7, 8, 1 1 and 12) or by a groove 35B, for example as a dovetail.

The tip 18 then partially covers the insert in the vicinity of the retaining element and penetrates into the through opening 35A or into the groove 35B forming the retaining element.

A method of manufacturing of at least one applicator 10, and advantageously a series of applicators 10 according to the invention is implemented in an installation shown diagrammatically in Figures 4, 5 and 6.

This installation comprises a mold 50 for making a foam block insert molding at least one insert 16 (Figure 4), a cross-linking device 52 of the foam block (Figure 5). It furthermore comprises an optional device (not shown) for cutting the foam block into several portions, in the case where several inserts 16 are received in a foam block.

In reference to Figure 6, the installation further comprises an optional device 54 for machining each individual foam block mounted on an insert to form a tip 18.

As shown in Figure 4, the mold 50 comprises 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 matter able to solidify in the cavity 62.

The first wall 60A delimits at least one orifice 66 for introducing an extended 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 able to cross-link, for example to vulcanize the block formed in the mold 50. It comprises for example means for emitting a luminous radiation, electromagnetic radiation or means of heating, such as an oven.

The machining device 54 comprises for example a milling-cutter or a rotating grinding wheel.

The method of manufacturing according to the invention will now be described, in reference to Figure 3.

This method comprises a step 1 10 of supplying at least one insert 16, advantageously a plurality of inserts 16 and of a step 1 12 of forming a tip 18 on each insert 16.

The step 1 12 comprises a phase 1 14 of arranging or of each insert 16 in the mold 50, a phase 1 16 of pouring of a block of flexible material on the or each insert 16 and a phase 1 18 of cross-linking of the block.

The step 1 12 further comprises an optional phase 120 of cutting (for example mechanical, by laser, by stream of water) of a common block into several portions and an optional machining phase 122 of each portion cut using the block to form a tip 18.

Initially, in the step 1 10, at least one insert 16, advantageously a plurality of inserts 16 such as described above are supplied. These inserts 16 are for example supplied separately or in the form of a cluster of inserts 16 connected together by breakable portions 123 (see Figure 16).

During the phase 1 14, in reference to figure 4, each insert 16 is introduced into an orifice 66 arranged in the first wall 60A of the mold. The extended element 24 is received in the wall 60A, with the exception of a distal segment 124 protruding into the molding cavity 62. The retaining element (here the head 26) also protrudes 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 even greater than 50.

In addition, an intermediate empty space 126 extends between each insert 16, and in particular between the distal segment 126 facing each insert 16.

Then, during the phase 1 16, a fluid material intended to form a foam is introduced into the molding cavity 62. This material is in particular a foaming material or a material foamed beforehand via mechanical agitation, for example by beating.

The material introduced as such fills the cavity 62. It is intended to form a common continuous block 128 of flexible material insert molding an individual insert 16 or a plurality of inserts 26. The block 128 is partially visible in figure 5. The continuous block 128 has a shape that is 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 retaining element of insert 16 is entirely embedded in the continuous block

128. In addition, the proximal segment 124 of each insert 16 is surrounded by material forming the continuous block 128.

During the phase 1 18, in reference to figure 5, the continuous block 128 is placed facing the device 52 in order to be subjected to a cross-linking, for example via vulcanization.

This cross-linking makes it possible in particular to create covalent chemical bonds between the molecules forming the material comprising the continuous block 128. This also makes it possible to provide the bond between the block 128 and each insert 16.

The block 128 insert molding each insert 16 is then extracted outside of the molding cavity 62.

Then, in the step 120 when several inserts 16 are received in the same block 128, the continuous block 128 is cut into a plurality of individual blocks 130A to 130E. Each individual block 130A to 130E contains at least one insert 26.

This cutting is for example carried out using a cutting edge, or using another cutting device such as for example a laser device.

In particular, cutting is carried out 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 Figure 5, each individual block 130A to 130E contains one single insert 16 after cutting.

In this example, each individual block 130A to 130E also has advantageously a shape that is substantially parallelepiped, for example a shape of a cube.

In an alternative embodiment, each individual block 130A to 130E has another shape, for example a cylindrical shape of axis A-A'.

The, during the phase 122, each individual block 130A to 130E is machined using the machining device 54 in order to adapt the shape of the outer surface of the block 130A to 130E to the outer surface 42 desired for the tip 18.

During this machining, a flange 44 of material is maintained in contact with the proximal transverse surface 32, and around the distal segment 124 of the extended element 24.

As shown in Figure 2, the applicators 10 formed as such can then be used to create 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 high quality of applicators 10 with varied shapes, wherein the tip 18 of the applicator is fixed in a very robust manner on the insert 16 bearing it via the cross-linking of the material intended to form the foam.

These applicators 10 are obtained at least cost, in particular taking into account the possibility of simultaneously insert molding a large number of inserts 16 by a common block 128 of flexible material, then of cutting the block 128 into several individual blocks 130A to 130E, in order to form a tip 18 on each insert 16.

The method is therefore particularly economical to implement and simplifies the manufacture of the applicators 10.

In one alternative embodiment, the machining phase 122 is omitted. The tips 18 are formed directly via the cutting of the continuous block 128 into a plurality of individual blocks 130A to 130E, with each portion containing an insert 16.

In one alternative embodiment, a single applicator 10 is made at a time by pouring a single block containing a single insert 16 then via cross-linking, without cutting the block.

In another alternative embodiment (Figure 1 1 ), at least two inserts 16 are assembled together by gluing, after the attaching of a tip 18 onto each insert 16, for example by an adhering part 200, the applicator can then form a roller or a sphere.

In another alternative embodiment, visible in Figure 12, the insert 16 is an axis of rotation having through openings 35A. The applicator then forms a roller.

In another alternative embodiment, shown in Figure 16, the inserts are placed against a wall 60A of the mold without being introduced into the orifices. The wall 60A then does not have an orifice.

The inserts 16 are advantageously braced on projections 300 formed on the wall 60A.

The term "one" must be understood to mean "at least one" unless mentioned otherwise.

Claims

1 . Method for manufacturing a cosmetic product applicator (10), the method comprising the following steps:

- supply of an insert (16);

- attaching of a flexible foam tip (18) onto the insert (16);

characterized in that the step of attaching comprises the following phases:

- arranging of the insert (16) in a mold (50);

- pouring of a product intended to form a foam on the insert (16);

- cross-linking of the product intended to form a foam on the insert (16) in order to form a foam block.

2. Method according to claim 1 , characterized in that it comprises the supply of a plurality of inserts (16), with the step of attaching comprising the following phases:

- insert molding of the plurality of inserts (16) by a continuous foam block (128) connecting the inserts (16) together;

- cutting of the continuous block (128) in order to separate the block (128) into a plurality of individual foam blocks (130A to 130E) each receiving an insert (16);

- forming of a tip (18) on each insert (16) using the individual block (130A to 130E) insert molding said insert (16);

3. Method according to claim 2, characterized in that after the cutting phase, each individual block (130A to 130E) insert molds a single insert (16), with the tip (18) being formed on each insert (16) using the individual block (130A to 130E) attached to said insert (16).

4. Method according to any of the preceding claims, characterized in that the step of forming of the tip (18) comprises the machining of the foam block fixed on the insert (16), after cross-linking.

5. Method according to any of the preceding claims, characterized in that the insert (16) comprises an extended element (24) and a retaining element, in particular a projection, a groove or a hole, the step of attaching comprising the pouring of the product on or in the retaining element.

6. Method according to claim 5, characterized in that the extended element (24) extends along a longitudinal axis (Α-Α'), the retaining element comprising a transverse surface relative to the extended element (24), with the phase of pouring comprising the arrangement of product intended to form a foam facing the transverse surface (32) to cover the transverse surface (32).

7. Method according to any of the preceding claims, characterized in that the foam forming the flexible tip (18) is an elastomer foam, advantageously chosen from polyurethane, NBR, SBR, PE or mixtures thereof.

8. Method according to any of the preceding claims, characterized in that the insert (16) is made from a material that is more rigid than the flexible tip (18), in particular a plastic material, a thermoplastic material, a thermosetting material, metal, wood, or a foam.

9. Use of an applicator (10) manufactured by the method according to any of the preceding claims for the creation of a cosmetic product packaging device (12) comprising a reservoir (14) of cosmetic product, the applicator (10) being intended to draw the cosmetic product present in the reservoir (14).

10. Cosmetic product applicator (10), comprising an insert and a flexible foam tip; characterized in that the flexible tip (18) is mounted on the insert (16) via cross- linking.

1 1 . 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 1 1 , characterized in that the insert (16) comprises an extended element (24) and a retaining element (26), in particular a radial protrusion relative to the extended element (24), a groove or an orifice, with the flexible tip (18) insert molding the retaining element.

13. Series of cosmetic product applicators (10), each applicator (10) in 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 insert molding several inserts (16)..