WO2020127799A1

WO2020127799A1 - Method for generating a digital model of a cosmetic product applicator

Info

Publication number: WO2020127799A1
Application number: PCT/EP2019/086407
Authority: WO
Inventors: Amine OUNACEUR; Camille Schreiber; Audrey THENIN
Original assignee: L'oreal
Priority date: 2018-12-19
Filing date: 2019-12-19
Publication date: 2020-06-25
Also published as: FR3090295A1; FR3090295B1

Abstract

The invention relates to a method for generating a digital model of an applicator member, the applicator member comprising a core (10) along an axis (X) and a row of patterns (19), each comprising an applicator element (18, 18a; 18b), the method comprising: (i) calculating a curve of intersection (32) between a helical surface (30) and an envelope surface (S, S1), (ii) calculating patterns (19), each pattern (19) being a replica, at a given position, of a reference pattern (19r) moved helically following the helical surface (30) from a reference position to the given position along the axis (X) in such a way that its distal end (20d) follows the curve of intersection (32), the reference pattern (l9r) extending within a volume delimited by the envelope surface (S) and having its end (20d) on the curve of intersection (32), and (iii) recording the digital model generated in a computer memory.

Description

METHOD FOR GENERATING A DIGITAL MODEL OF A COSMETIC

PRODUCT APPLICATOR

The present invention relates to a method for generating, using a computer- assisted design tool, a digital model of an applicator member, the applicator member comprising a core that is elongate along a longitudinal axis X and at least one row of applicator patterns, the applicator patterns each comprising one or more applicator elements, and a method for producing a corresponding applicator member.

Technical field

Applicator members for applying cosmetic product are usually produced using one or more molds made on the basis of a digital model of the applicator member. The use of molds to produce applicator members requires simple shapes that can be demolded. To produce applicator members having rows of applicator elements extending helically around the core, the core is twisted after production.

International application WO 2016/050790 discloses an applicator for applying a cosmetic product, comprising a molded applicator member comprising a core and applicator elements extending from the core, the core comprising at least two helical grooves extending along the longitudinal axis of the core.

Application W02008/113939 describes an applicator for applying a cosmetic product, produced by additive manufacturing, having a plurality of grooves extending helically around the core over at least one turn.

There is a need to design applicator members of complex shapes.

Summary of the invention

The invention aims to achieve this objective and relates, according to one of its aspects, to a method for generating, using a computer-assisted design tool, a digital model of an applicator member, the applicator member comprising a core that is elongate along a longitudinal axis and at least one row of applicator patterns, the applicator patterns each comprising one or more applicator elements,

the method comprising the following steps, implemented by computer in the computer-assisted design tool:

i. calculating at least one curve of intersection between a helical surface that is coaxial with the longitudinal axis of the core and an envelope surface of the applicator member, ii. calculating a plurality of applicator patterns of the row, each applicator pattern being a replica, at a given position along the longitudinal axis of the core, of a predefined reference applicator pattern having at least been moved helically following the helical surface from a reference position to the given position along the longitudinal axis of the core in such a way that its distal end follows the curve of intersection, the reference applicator pattern extending within a volume delimited by the envelope surface of the applicator member and having its distal end on the curve of intersection, and

iii. recording the digital model thus generated in a computer memory.

The“ longitudinal axis of the core” means the line connecting all of the centers of gravity of the cross sections of the core. The longitudinal axis may be a central axis, or even an axis of symmetry for the core, notably when the core has a circular cross section or a cross section in the overall shape of a regular polygon.

The expression“ moved helically following the helical surface from a reference position to the given position along the longitudinal axis of the core (X)” means that the reference applicator pattern moves, between its reference position and the given position, in translation along the longitudinal axis by a distance corresponding to the distance between the reference position and the given position along the longitudinal axis of the core and a rotation about the longitudinal axis of the core by an angle corresponding to the angle between the radial axis defined by the distal end of the reference applicator pattern and the radial axis defined by the curve of intersection at the given position.

With such a method for generating the digital model, it is possible to easily produce a digital model for applicator members of relatively complex shape, in particular having an envelope surface of complicated shape and/or whose helical surface performs a high number of turns around the longitudinal axis of the core.

Preferably, the reference applicator pattern comprises one or more applicator elements.

Such a method also makes it possible to easily generate a model for an applicator member in which the distribution of applicator elements appears to be substantially random, in particular by playing with the distance between the successive applicator patterns of a row of applicator elements, with the number of turns of the helical surface around the longitudinal axis of the core, with the shape of the reference applicator patterns, in particular the shape of the applicator element or elements and/or the orientation of the applicator element or elements relative to the core and relative to one another, or with the shape of the envelope surface of the applicator member.

The method may comprise a step of calculating an external surface of the core of the applicator member, the applicator pattern, preferably, being such that the applicator element or elements of the applicator patterns extend from the surface of the core.

The digital model is configured so that the applicator member is obtained by additive manufacturing. This means that the various elements of the applicator member are designed in the digital model such that they are made from the same material as each other within the applicator member. This also makes it possible to design complex shapes that can be obtained in a single step, without the need to use a mold.

Preferably, the applicator member comprises at least two rows of applicator patterns, step (i) comprising calculating at least two curves of intersection each defined by the intersection between a helical surface that is coaxial with the longitudinal axis of the core and the envelope surface, step (ii) comprising calculating an applicator pattern for each row, each applicator pattern being a replica, at a given position along the longitudinal axis of the core, of a predefined reference applicator pattern of said row having been moved helically following the corresponding helical surface from a reference position to the given position along the longitudinal axis of the core in such a way that its distal end follows the corresponding curve of intersection, the reference applicator pattern of each row extending within the envelope surface of the applicator member and having its distal end on the corresponding curve of intersection.

Preferably, the reference applicator patterns of at least two of the rows are of identical shape.

As an alternative, the reference applicator patterns of at least two rows are of different shapes. Preferably, the reference applicator pattern of one row consists of an applicator element in the form of a spike and the reference applicator pattern of another row consists of an applicator element comprising a body and at least one protuberance extending from the body, or in the form of a loop, open or closed. Preferably, said at least two helical surfaces have the same shape and are intertwined; the spirals of one of the helical surfaces may extend at the same distance from the two adjacent spirals of the other helical surface.

The longitudinal axis of the core may be rectilinear or may have one or more curves between its distal and proximal ends. Preferably, the longitudinal axis of the core is rectilinear and coincident with the longitudinal axis of a stem supporting the applicator member.

The core may have a cross section of circular or polygonal shape, such as square, rectangular or triangular. The term“ cross section” means any section produced in a plane orthogonal to the longitudinal axis of the core.

The core may have a cross section that is constant from its proximal end to its distal end. As an alternative, the core has a cross section the shape and/or dimension(s) of which varies along its longitudinal axis. For example, the cross section may reduce on approach to a distal and/or proximal end. Preferably, the section reduces on approach to the distal end of the applicator member.

The core may be solid or hollow.

The core may be made of a single material or of a plurality of materials, while still being monobloc. For example, the core comprises a center of a flexible material covered with a casing of a more rigid material, the two materials being fused together at their joins.

The core may comprise one or more longitudinal openings. The latter allow product accumulation. Thus the autonomy of the applicator and its capacity for holding cosmetic product are increased. The openings may also allow a degree of flexibility of the core. The longitudinal openings may extend helically over the core. The method may comprise a step of calculating one or more longitudinal openings on the external surface of the core by intersection of the external surface of the core with one or more secondary helical surfaces that are coaxial with the longitudinal axis of the core, in particular one or more secondary helical surfaces that are parallel to the helical surface.

The core may comprise one or more grooves. The latter allow product accumulation. Thus, the autonomy of the applicator and its capacity for holding cosmetic product is increased. The method may comprise a step of calculating one or more grooves on the external surface of the core, in particular two grooves, by intersection of the external surface of the core with one or more secondary helical surfaces that are coaxial with the longitudinal axis of the core, in particular one or more secondary helical surfaces that are parallel to the helical surface.

The or at least one, or better still each, secondary helical surface may be at the same distance from the adjacent spirals of the helical surface or surfaces.

As an alternative, the or at least one, or better still each, secondary helical surface is coincident with the or one of the helicoid(s).

As an alternative, the core is cylindrical.

Preferably, the helical surface or surfaces have a constant pitch along the longitudinal axis of the core.

As an alternative, the helical surface or surfaces have a variable pitch along the longitudinal axis of the core.

Preferably, the helical surface or surfaces form(s), around the longitudinal axis of the core, at least one turn, better still a plurality of turns, in particular between 2 and 60 turns, better still between 3 and 40 turns, over the entire length of the applicator member. Such a number of turns allows the applicator member to have an appearance of being furnished with applicator elements and gives the impression that the applicator elements are arranged at random.

Preferably, the reference applicator pattern of the or of at least one row comprises a plurality of applicator elements, in particular two applicator elements. Preferably, the reference applicator pattern of each row comprises a plurality of applicator elements, in particular two applicator elements.

Preferably, at least two of the applicator elements of the reference applicator pattern of the or of at least one row are different, in particular one of the applicator elements is a spike and another of the applicator elements comprises a body and at least one protuberance extending from the body or in the form of a loop.

The applicator elements of the reference applicator pattern of the or of at least one row, better still of each row, may extend along axes of elongation that are mutually coplanar, in particular coplanar with a transverse plane of the core.

As an alternative, the applicator elements of the reference applicator pattern of the or of at least one row, better still of each row, extend along axes of elongation that are not mutually coplanar. Preferably, the applicator elements of the reference applicator pattern of the or of at least one row, better still of each row, are spaced apart by a distance of between 0.1 mm and 5 mm, better still of between 0.5 mm and 1 mm.

Preferably, the applicator elements of each applicator pattern of a or of each row have a ratio of their heights in pairs that is constant along the or each of the rows. In this case, step (ii) of the method comprises calculating a plurality of applicator patterns of the row, each applicator pattern being a replica, at a given position along the longitudinal axis of the core, of a predefined reference applicator pattern having been moved helically following the helical surface from a reference position to the given position along the longitudinal axis of the core, and having undergone a homothety where the envelope surface varies in section, in such a way that its distal end follows the curve of intersection, the reference applicator pattern extending within a volume delimited by the envelope surface of the applicator member and having its distal end on the curve of intersection.

As an alternative, the distal ends of the applicator elements of each applicator pattern of a or of each row are spaced apart by a constant distance along the or each row. In this case, step (ii) of the method comprises calculating a plurality of applicator patterns of the row, each applicator pattern being a replica, at a given position along the longitudinal axis of the core, of a predefined reference applicator pattern having only been moved helically following the helical surface from a reference position to the given position along the longitudinal axis of the core, in such a way that its distal end follows the curve of intersection, the reference applicator pattern extending within a volume delimited by the envelope surface of the applicator member and having its distal end on the curve of intersection.

As an alternative, the reference applicator pattern of the or of at least one row comprises a single applicator element. Preferably, the reference applicator pattern of each row comprises a single applicator element.

Preferably, the applicator element or at least one of the applicator elements of the reference applicator pattern of the or of at least one row, better still of each row, comprises a body and at least one protuberance extending from the body.

As an alternative, the applicator element or at least one of the applicator elements of the reference applicator pattern of the or of at least one row, better still of each row, forms a loop. The loop may be open or closed. The term“ open loop” means that the contour of the loop has an opening forming an opening. This may be positioned at a non-zero distance from the core, for example in the central portion, so as to separate the applicator element into two separate parts each connected to the core by one of the two connection feet. The opening may be positioned elsewhere, for example at the connection to the core such that the applicator element is connected to the core by a single foot.

The fact that the loop is open may allow eyelashes to pass through the opening and/or confer greater flexibility on wiping.

The opening may have a width less than or equal to 0.3 mm, better still less than or equal to 0.2 mm, even better still less than or equal to 0.1 mm.

The applicator element or at least one of the applicator elements of the reference applicator pattern of the or of at least one row, better still of each row, may comprise a distal end that is enlarged or not rectilinear, in particular curved.

The applicator element or at least one of the applicator elements of the reference applicator pattern of the or of at least one row, better still of each row, may be hollow.

The applicator element or at least one of the applicator elements, better still each applicator element, of the reference applicator pattern of the or of at least one row, better still of each row, may extend in a plane transverse to the longitudinal axis of the core.

The applicator element or at least one of the applicator elements, better still each applicator element, of the reference applicator pattern of the or of at least one row, better still of each row, may extend in a plane longitudinal to the longitudinal axis of the core.

The applicator element or at least one of the applicator elements, better still each applicator element, of the reference applicator pattern of the or of at least one row, better still of each row, may extend along an axis of elongation making a non-zero angle with a plane transverse to the longitudinal axis of the core. This makes it possible in particular to have a better distribution of the applicator elements around the core, in particular a better proliferation, and to prevent the appearance, visually, of large areas without applicator elements when seen from the side.

Preferably, the applicator element or at least one of the applicator elements, better still each applicator element, of the reference applicator pattern of the or of at least one row, better still of each row, extends along an axis of elongation making a non-zero angle with the plane defined by the longitudinal axis of the core and the center of gravity of the base of the axis of elongation with the core. This makes it possible in particular to have a better distribution of the applicator elements around the core, in particular a better proliferation, and to prevent the appearance, visually, of large areas without applicator elements when seen end-on.

Preferably, the distal end of each reference applicator pattern is defined by the or at least one applicator element of the reference applicator pattern.

Preferably, the applicator elements of each applicator pattern of the or of each row defining the distal end of the applicator pattern have the same shape, in particular comprising a body and at least one protuberance extending from the body.

Preferably, the applicator elements of each applicator pattern of the or of each row defining the distal end of the applicator pattern have axes of elongation that all make the same angle with the tangent to the corresponding curve of intersection.

Consecutive applicator patterns of the row or of one and the same row may be spaced apart along the longitudinal axis by a distance of between 0.1 mm and 5 mm, better still between 0.5 and 1 mm.

Preferably, consecutive applicator patterns of the row or of one and the same row are spaced apart by the same distance.

Preferably, the reference applicator pattern or patterns do not have an axis of symmetry.

The reference applicator pattern or patterns may have a plane of symmetry, in particular a plane transverse or longitudinal to the longitudinal axis of the core.

As an alternative, the applicator pattern or patterns do not have a plane of symmetry.

Preferably, the applicator member does not have an axis of symmetry.

Preferably, the applicator member does not have a plane of symmetry.

The or each row may comprise a number of applicator elements of between 2 and 500 elements, better still of between 5 and 300.

Preferably, the envelope surface has a circular section.

The envelope surface may have any shape. Preferably, the envelope surface is cylindrical.

As an alternative, the envelope surface section has a continuously variable dimension along the longitudinal axis of the core, in particular decreasing toward the ends of the applicator member, and possibly passing through one or more extrema. For example, the envelope surface may have, seen from the side of the applicator member, a shape that is substantially polygonal, oval, in particular circular, ogival, oblong or a peanut shape.

The invention also relates to a method of production, using a production tool, of an applicator member on the basis of the file of a digital model generated by the method as described above.

Such a method allows an applicator to be produced in a single step, wherein the various elements constituting the applicator are made from the same material as each other without the need to use a mold.

Such a method allows a monobloc applicator member to be produced, wherein the various elements constituting the applicator member are made from the same material as each other without the need to use a mold.

Such a method also makes it possible to develop new forms of applicator, particularly ones which are impossible to produce by injection molding because of the presence of undercuts and/or closed loops.

Preferably, the method of production is automatic.

Preferably, a blank of the applicator member or the applicator member itself is produced in successive layers, on the basis of a file of the digital model of the applicator member, generated by the method as described above.

Preferably, the successive layers are predetermined in the file of the digital model.

Preferably, the method of production is controlled by the file of the digital model.

Such a method also allows the development of new forms of applicator member, particularly ones which are impossible to produce by injection molding because of the presence of undercuts.

Preferably, the method comprises the steps consisting of

a. depositing a layer of a flowable raw material on a printing substrate, b. locally solidifying the raw material to form a layer corresponding to a layer determined on the basis of the digital model of the applicator member,

c. repeating steps a. and b., the layer of raw material previously deposited forming the printing substrate, in order to produce, continuously in successive layers, solid parts which adhere to one another so as to form the applicator member according to the digital model.

Such a method does not include a step of designing a mold.

Preferably, the successive layers have a constant thickness.

The raw material may be liquid, in particular a photo-crosslinkable material, or powdery material.

In the case of a photo-crosslinkable raw material, in step (ii), the raw material may be solidified slice by slice, by irradiation of the photo-crosslinkable raw material.

In the case of a powdery raw material, step (ii) can be performed by sintering the powdery raw material layer by layer.

The production method by additive manufacturing may be a process of filament deposition printing (FDM), stereo lithography (SLA), Multi Jet Fusion (MJF), Selective Laser Sintering (SLS) or Digital Light Processing (DLP), in particular CLIP (Continuous Liquid Interface Production), preferably MLF.

Preferably, the production method is a Multi Jet Fusion technique. The method may comprise the steps consisting of:

a. depositing a layer of powdery material on a printing substrate, b. dispensing one or more coalescence agents and coalescence modifiers onto parts of the layer which are determined on the basis of the digital model of the applicator member,

c. applying energy to the layer of powdery material, in particular by irradiation with infrared or near infrared light, so as to cause at least partial fusion of the parts on which the coalescence agent or agents have been applied,

d. cooling the layer of powdery material to solidify the fused parts, e. repeating steps a. to d., the layer of powdery material previously deposited forming the printing substrate, in order to produce continuously, in successive layers, solid parts adhering to one another so as to form the applicator member.

The powdery material may be a material in powder form selected from a semi crystalline thermoplastic material, in particular a polyamide such as nylon 12 or PA220, preferably pure, metal, composite, ceramic, glass, resin or polymer.

The coalescence agent or agents may be a composition of an ink type comprising carbon black, such as for example the ink composition CM997A available in particular from the Hewlett-Packard Company. The coalescence agent or agents may additionally comprise an infrared and/or near infrared and/or visible light absorber, in particular the ink compositions CE039A and CE042A available in particular from the Hewlett-Packard Company.

The coalescence modifying agent or agents may be a colloidal ink, a dye-based ink or a polymer-based ink. The coalescence modifying agent or agents may comprise solid compounds or compounds in solution, in particular may be a saline solution. The coalescence modifying agent or agents may be the ink composition CM996A or CN673A available in particular from the Hewlett-Packard Company. Preferably, the layer of powdery material has a thickness of between 90 and 110 microns.

Preferably, the printing plate has a dimension ranging from 10 cm x 10 cm, to 100 cm x 100 cm.

The method for producing the applicator may be as described in international application W02015106816.

As an alternative, the method of production by additive manufacturing comprises:

a. localized irradiation by a light source, notably a laser, in a predefined build zone, of a fluid photo-crosslinkable material contained in a vat so as to form one or more polymerized solid parts in the polymerizable material in said build zone, the polymerized solid part or parts being attached to a substrate, the irradiation site or sites in the predefined build zone being determined on the basis of the digital model of the applicator member, b. moving the substrate and the polymerized solid parts attached to the latter relative to the light source, in the direction away from the build zone so as to free the polymerized solid parts from the build zone, the build zone once again filling up with fluid photo-crosslinkable material,

c. repeating steps a) and b) to produce continuously, in successive layers, solid parts which adhere together so as to form the applicator member.

The vat comprises, preferably, a surface in fluidic communication with a source of polymerization inhibitor, step a) being performed while forming or keeping a fluid zone between the predefined build zone and said surface, in which fluid zone the polymerization of the fluid photo-crosslinkable material is inhibited by the polymerization inhibitor.

Preferably, the polymerization inhibitor is oxygen. Preferably, the fluid zone has a height which is less than or equal to 1 mm, preferably between 500 pm and 0.01 pm, better still between 100 pm and 10 pm.

Preferably, the localized irradiation and movement of the support are continuous, wherein the fluid zone and the build zone at their interface have a polymerization gradient such that production of the applicator member is substantially continuous. This makes it possible to limit the presence of visible strata as found in methods of production by additive manufacturing that produce the object layer by layer.

The method comprises preferably an additional step of heating the applicator member formed. This makes it possible to harden the structure of the applicator member manufactured and to smooth out its surface.

The method comprises preferably an additional step of heating the applicator member formed. This improves polymerization of the material of the applicator member produced.

The method for producing the applicator may be as described in international applications WO2014126830 and WO2014126837.

Brief description of the drawings

The invention may be better understood from reading the following detailed description of non-limiting implementation examples thereof, and with reference to the appended drawing, in which:

[Fig 1] shows an application and packaging device according to the invention, [Fig 2] shows a digital model of an applicator member produced in accordance with the invention,

[Fig 3] is an end-on view, i.e. along III, of the digital model of figure 2,

[Fig 4] is a view of a detail of the applicator member of figures 1 to 2,

[Fig 5] shows the envelope surface of the applicator member of figures 1 to 4, [Fig 6] is a view in cross section of the applicator member of figures 1 to 5,

[Fig 7] is a view in cross section of the applicator member of figures 1 to 5,

[Fig 8] shows an applicator element of the applicator member of figures 1 to 7, [Fig 9] shows one of the steps in the production of a digital model according to the invention,

[Fig 10] shows one of the steps in the production of a digital model according to the invention, [Fig 11] shows one of the steps in the production of a digital model according to the invention,

[Fig 12] shows one of the steps in the production of a digital model according to the invention,

[Fig 13] is a detail of figure 12,

[Fig 14] shows one of the steps in the production of a digital model according to the invention,

[Fig 15] is a perspective view of an alternative applicator member produced in accordance with the invention,

[Fig 16] is an end-on view along XVI of the applicator member of figure 15, [Fig 17] shows the detail XVII of the applicator member of figure 15,

[Fig 18] shows an applicator element of the applicator member of figure 15,

[Fig 19] is a view along XIX of the applicator element of figure 18,

[Fig 20] shows a cross section along XX-XX of figure 15,

[Fig 21] shows a longitudinal section along XXI- XXI of figure 15,

[Fig 22] is a schematic perspective representation in profile of an alternative applicator member produced in accordance with the invention,

[Fig 23] is a view of a detail of the applicator member of figure 22,

[Fig 24] is a view along XXIV of the applicator member of figure 22,

[Fig 25] a and b show an applicator element of the applicator member of figures 22 to 24,

[Fig 26] shows envelope surfaces of the applicator member of figures 22 to 24, [Fig 27] shows envelope surfaces of the applicator member of figures 22 to 24, [Fig 28] is a cross section through the applicator member of figures 22 to 27, [Fig 29] is a cross section through the applicator member of figures 22 to 27, [Fig 30] is a schematic perspective representation of an alternative applicator member produced in accordance with the invention,

[Fig 31] is an end-on view of the applicator member of figure 30,

[Fig 32] shows a detail of the applicator member of figures 30 and 31,

[Fig 33] shows an applicator element of the applicator member of figures 31 and 32, [Fig 34] is a schematic perspective representation of an alternative applicator member produced in accordance with the invention,

[Fig 35] is an end-on view of the applicator member of figure 34,

[Fig 36] shows a detail of the applicator member of figures 34 and 35,

[Fig 37] shows, in cross section, the applicator member of figures 28 and 29, [Fig 38] a to f show steps in the production of the applicator member according to the invention,

[Fig 39] shows a device for producing the applicator member according to the production steps of figures 38a-f,

[Fig 40] shows a first step of an alternative method for producing the applicator member according to the invention, and

[Fig 41] shows a second step of the alternative method for producing the applicator member according to figure 52.

Detailed description

Figure 1 shows a packaging and application device 1 produced in accordance with the invention, comprising an applicator 2 and an associated container 3 containing a product P to be applied to the eyelashes and/or eyebrows, for example mascara or a care product.

The container 3 comprises, in the example in question, a threaded neck 4 and the applicator 2 comprises a closure cap 5 designed to be fastened on the neck 4 so as to close the container 3 in a sealed manner when it is not in use, the closure cap 5 also constituting a gripping member for the applicator 2.

The container 3 may also be produced differently.

The container 3 also comprises a wiping member 6, for example inserted into the neck 4.

The applicator 2 comprises a stem 7 of longitudinal axis Y, which is attached at its upper end to the closure cap 5 and at its lower end to an applicator member 8. The latter comprises a core 10 bearing applicator elements 18 that extend from the core 10 and all around the latter.

This wiping member 6, which may be any wiping member, comprises, in the example in question, a lip designed to wipe the stem 7 and the applicator member 8 when the applicator 2 is withdrawn from the container 3. The lip defines a wiping orifice 6a having a diameter adapted to that of the stem.

The wiping member 6 may be made of elastomer.

The wiping member 6 may comprise a wiping orifice 6a with a circular shape, optionally with slots.

The diameter of the wiping orifice 6a of the wiping member 6 is for example between 2.5 and 6 mm, being for example around 3.5 mm or 5 mm.

The wiping member 6 may optionally have undulations, allowing the wiping orifice to widen more easily when the applicator member 8 passes through.

The wiping member may also be adjustable, if appropriate.

In the example illustrated, the stem 7 has a circular cross section, but it would not constitute a departure from the scope of the present invention if the stem 7 had a different cross section, it then being possible to fasten the cap 5 on the container 3 in some other way than by screwing, if necessary. The wiping member 6 is adapted to the shape of the stem 7 and to that of the applicator member 8, if appropriate.

Preferably, and as in the example in question, the longitudinal axis Y of the stem 7 is rectilinear and coincident with the longitudinal axis of the container 3 when the applicator 2 is in place thereon, but it would not constitute a departure from the scope of the present invention if the stem 7 were not rectilinear, forming for example an elbow.

If need be, the stem 7 may have an annular narrowing at its portion that is positioned opposite the lip of the wiping member 6, so as not to mechanically stress the latter unduly during storage.

The stem 7, to which the applicator member 8 is fixed, may be at least partially, and in particular completely, flexible, in particular in the vicinity of the applicator member.

The applicator member 8 may be fixed to the stem 7 by any means, and in particular by force-fitting, snap-fastening, adhesive bonding, welding, stapling or crimping, in a corresponding housing provided at the end of the stem 7.

As shown in figure 2, the applicator member 8 may comprise an end piece 9 for fastening it in a corresponding housing in the stem 7.

One example of an applicator member according to the invention is described in relation to figures 2 to 4 hereinbelow. The applicator member 8 comprises a core 10 and a plurality of applicator patterns 19 extending from the core 10. As shown in figure 2, the core 10 is of a shape that is elongate along a longitudinal axis X. The latter is rectilinear but, as an alternative, may be of another shape, notably having one or more curvatures between the distal and proximal ends. The longitudinal axis X is an axis of symmetry for the core.

As shown in figures 2 and 4 in particular, the core 10 comprises two grooves 16 and 17 each turning around the longitudinal axis of the core X following two respective helices 13 and 15. The two helices 13 and 15 are opposite one another relative to the longitudinal axis X and have the same pitch. The helices 13 and 15 extend around the axis X over more than one turn, in particular over more than 6 turns, for example over 40 turns.

The applicator member 8 bears a plurality of applicator patterns 19 extending from the core 10, each comprising a single applicator element 18. The applicator patterns 19 are all substantially identical in shape, notably give or take their height.

The applicator elements of the embodiment relating to figures 1 to 8 are described in detail hereinbelow.

In the example shown in figure 8, the applicator elements 18 comprise a body 20 and two protuberances 22a and 22b extending laterally from the body 20.

The body 20 of the applicator elements 18 comprises a rectilinear proximal portion 20a and a non-rectilinear distal portion 20b, as shown in figures 3, 4, 6 to 8.

The bodies 20 of the applicator elements 18 each extend along an axis of elongation C contained in a plane transverse to the longitudinal axis X of the core 10.

The axis of elongation C comprises a rectilinear part C_a along which the proximal portion of the body 20a extends, and at least one non-rectilinear, notably curved, part Cb along which the distal portion of the body extends. The axis of elongation C defines a plane of elongation M, notably coincident with a transverse plane of the longitudinal axis X.

The rectilinear part C_a of the axis of elongation C is oriented radially, namely along a radial axis of the core.

In an alternative form that is not illustrated, the rectilinear part C_a of the axis of elongation is inclined relative to the radial axis of the core at the base of the body. Thus, the bodies 20 of the applicator elements 18 are transverse to the longitudinal axis X of the core and inclined relative to the radial axis of the latter at their base. In the embodiment shown, the proximal portion 20a of the bodies 20 of the applicator elements 18 has a circular cross section. As an alternative, the cross section is polygonal, for example triangular or rectangular.

The proximal portion 20a has a cross section that decreases from the base toward the distal portion 20b, as shown. That allows the end of the applicator element to be given flexibility that makes its contact with the skin gentler.

The height L of the body, measured from the core along the rectilinear part C_a of the axis of elongation C, from the base of the applicator element 20_p to its distal end 20_d, may be between 0.2 mm and 5 mm, preferably between 0.5 mm and 3 mm.

The non-rectilinear distal portion 20b of each body 20 is curved, preferably in the form of a hook.

The non-rectilinear distal portion 20b has a cross section the dimension of which is constant along the axis Cb, with a rounded free end.

It may have a curve with a radius of curvature r of between 0.2 and 2 mm. The radius of curvature r corresponds to the radius of curvature of the axis of the non-rectilinear part, as shown in figure 8.

The distal portion 20b of the body extends in an arc of a circle of angular extent Q of between 10° and 180°, better still between 90° and 180°, better still between 135° and 180°, for example substantially equal to 150°.

Preferably, the distal portion has a radius of curvature r of between 5% and 40% of the height L of the body, better still between 10% and 25%, even better still between 15% and 20%. In the example shown, the radius of curvature is constant along the curved portion, and represents 15% of the height of the body. Preferably, the radius of curvature r is substantially equal to the height of the curved part Cb of the axis of elongation C measured along the rectilinear part of the axis Ca.

The applicator element 18 comprises two protuberances 22a and 22b each extending along an axis of extension P extending in the same plane of elongation M as the body 20, in particular in a plane transverse to the longitudinal axis X of the core 10. Preferably, they extend at different heights on the body 20, from the rectilinear portion 20a of the body, on the same side of the body 20 as the distal portion 20b of the body 20. The protuberances 22a and 22b, as shown, are all of substantially identical shape. They have a constant cross section and a rounded free end. As an alternative, the cross section may vary, in particular decreasing toward their free end.

The protuberances 22a and 22b extend on the same side of the body 20. In the example shown, the curvatures of the protuberances 22a and 22b are oriented in the same circumferential direction as the non-rectilinear distal end.

The protuberances 22 are concave toward the core 10.

The axes of extension P of the protuberances 22a and 22b are preferably curved. They are preferably concentric to the non-rectilinear part C_t>. These have a radius of curvature r_p that is preferably substantially identical to the radius of curvature r of the curved distal portion 20b. The radius of curvature r_p corresponds to the radius of curvature of the axis of extension. Preferably, the protuberances extend in an arc of a circle of angular extent q_r which is less than that of the distal end 20b.

Preferably, the distal end 20b and the protuberances 22a and 22b extend laterally from the body 20 over the same distance d from the rectilinear part of the axis of elongation C.

One of the protuberances 22a extends in the distal half of the applicator element, in such a way as to constitute reserves of product at a distance from the core.

The applicator elements 18 are arranged in rows of applicator elements. The rows of applicator elements 18 extend around the core, each following the helical path of one of the two helices 13 and 15. These rows extend between the two grooves 16 and 17, preferably at the same distance from the latter. This does not have to be the case. For example, according to one alternative, the applicator member 8 comprises rows of applicator elements that do not follow the helical path of the grooves 16 and 17. The rows of applicator elements 18 may be helical but extend along helical grooves 16 and 17.

In this embodiment, the core has a cross section that is constant from its proximal end to its distal end. In an alternative form that has not been shown, the distal and/or proximal ends of the core are tapered, which facilitates insertion into the container containing the product.

The length H of the core 10 is, for example, between 15 mm and 27 mm.

As an alternative, the core is a solid cylindrical core and the rows of applicator elements 18 extend helically or along the longitudinal axis of the core X. Each row has, for example, between 2 and 500 applicator elements, better still between 5 and 200 applicator elements, as described above.

The applicator elements are aligned with one another at their base along the corresponding row.

In the example in question, as can be seen in particular in figure 5, the applicator element 8 has an envelope surface S, the longitudinal axis of which is rectilinear and coincident with the longitudinal axis X of the core 10. The envelope S has symmetry of revolution about said axis X, being of elongate shape, of circular section and becoming enlarged at its center, as can be seen notably figure 5. The envelope surface S has, in the example shown, a cross section the dimension of which varies over the entire length of the applicator member 8, notably exhibiting two minima, at points corresponding substantially to the distal end and to the proximal end of the applicator member, and a maximum in the middle of the length H of the applicator member 8.

It would not constitute a departure from the scope of the invention if an envelope surface of another shape, for example spherical, ovoid, frustoconical or biconical, or exhibiting several extrema, were to be considered. For example, the envelope surface may have, seen from the side of the applicator member, a shape that is substantially polygonal, oval, in particular circular, ogival, oblong or a peanut shape.

The distance between the base of two consecutive applicator patterns 19 of the same row may be between 0.1 mm and 5 mm, preferably between 0.5 mm and 1 mm.

In the example shown, the planes of elongation of all the applicator elements are coincident with a transverse plane of the core so that the distal portions 20b and the protuberances 22 of the applicator elements 18 all extend circumferentially to the core 10 in the clockwise or counterclockwise direction starting from the proximal portion of the body 20a.

Preferably, the applicator elements 18 of one and the same row have distal portions 20b and protuberances 22 all extending from their respective proximal portion 20a in the same circumferential direction. The applicator elements 18 of adjacent rows around the core 10 may have distal portions 20b and protuberances 22 which extend from their respective proximal portion 20a in opposite circumferential directions as is shown in particular in figure 7. As an alternative, all the applicator elements have distal portions 20b and protuberances 22 all extending from their respective proximal portion 20a in the same circumferential direction.

Like the cross section of the envelope surface S of the applicator member, the height L of the proximal portions of the bodies may vary over all or part of the length of the applicator member. This height may exhibit one or more extrema, notably a maximum mid way along the length. The height of the bodies may equally diminish on nearing at least one of the proximal and distal ends of the applicator member, preferably on nearing the proximal and distal ends of the applicator member.

The applicator member 8 described above is produced on the basis of a file comprising a digital model created using a computer-assisted design tool.

The method for creating the corresponding digital model will now be described with reference to figures 9 to 14.

In a first step, the longitudinal axis X of the core and an envelope surface S of the applicator member are defined in the computer design tool, as shown in figure 9.

In a second step shown in figures 10 and 11, a helical surface 30 coaxial with the longitudinal axis of the core X is defined. The latter cuts the envelope surface S along a curve of intersection 32 shown in figure 11. Preferably, the helical surface extends around the longitudinal axis X over a plurality of turns, for example 14 turns in the present case.

In a third step shown in figures 12 and 13, the core 10 is defined in the form of a cylinder and a reference applicator pattern 19r is positioned within the volume defined by the envelope surface in such a way that its distal end 20d is tangential to the curve of intersection 32, as can be seen in figure 13, and that its proximal end 20p extends from the core 10. In the example shown, the reference applicator pattern 19r comprising a single applicator element 18r as described above extends radially to the longitudinal axis of the core X. However, this does not have to be the case. In the example shown, the core 10 is defined in the form of a cylinder prior to the primary applicator pattern, but this does not have to be the case, and in particular the core could have another shape and/or be defined subsequently, or during the first or second step.

In the fourth step, the applicator patterns 19 are each defined by replicating the reference applicator pattern 19r along the curve of intersection 32, the reference pattern 19r being moved helically following the helical surface, from a reference position to the position of said applicator pattern 19 on the longitudinal axis of the core X and optionally undergoing a homothety in the case where the height of the applicator elements varies, such that its distal end 20d remains tangential to the curve of intersection 32. The digital model shown in figure 14 is thus obtained.

These steps may be repeated to create one or more identical or non-identical additional rows of applicator patterns. In the case shown in figures 1 to 8, these steps may be repeated with a helical surface 30' intertwined with the helical surface 30, and having spirals at the same distance from the adjacent spirals of the helical surface 30, and with a reference applicator pattern 19r' of the same shape but with protuberances oriented in the opposite direction circumferentially.

One or more helical grooves like that shown in figures 2 to 7 may also be defined by intersection between a helical surface intertwined with the preceding helical surfaces, and the surface of the core 10.

In the embodiment illustrated previously, the applicator patterns 19 comprise only a single applicator element 18.

As an alternative, as shown in figures 15 to 29, the applicator pattern 19 comprises a plurality of applicator elements 18. These alternatives differ from the first embodiment by virtue of the shape of the applicator patterns and their arrangement on the core 10.

Only the differences between these embodiments and the first embodiment are described.

In the example shown in figures 15 to 21, the reference applicator pattern 19r comprises two types of applicator elements:

- applicator elements 18a comprising a body 20 and protuberances 22 extending laterally from the body 20, and

- applicator elements 18b in the form of spikes.

The applicator elements 18b have a circular section and taper toward their distal end. As shown in figure 21, the applicator elements 18b may all be inclined toward the distal end 11 of the applicator member 8 relative to a radius at their base, by the same angle a of between 0° and 90°, better still between 5 and 30°, even better still between 10 and 20°.

The bodies 20 of the applicator elements 18a may be in the form of spikes with a circular section and tapering toward their distal end. As shown in figure 20, the bodies 20 of the applicator elements 18a may extend along an axis of extension C in a plane transverse to the longitudinal axis of the core 10. The axes of extension may all be inclined relative to the radial axis R at their base by the same angle b of between 0 and 90°, better still between 5 and 30°, even better still between 10 and 20°.

The bodies 20 of the applicator elements 18a may thus be all transverse to the longitudinal axis X of the core and all inclined relative to the radial axis R at their base.

In the example shown in figures 15 to 21, the applicator elements 18a and 18b of the reference applicator pattern 19r are not coplanar.

The applicator elements 18a comprise several protuberances 22 extending along three sides of the body 20. As shown in figure 20, the applicator elements 18a may comprise one or more protuberances 22a and 22b each extending along an axis of extension P contained in a transverse plane of the core 10, and one or more protuberances 22c each extending along an axis of extension contained in a longitudinal plane of the core toward the distal end 11 of the applicator member 8. The protuberances 22a and 22b may extend on either side of the body 20. None of the applicator elements 18 comprise protuberances extending toward the proximal end 14 of the applicator member 8.

The fact that all of the applicator elements 18a are oriented in the same way relative to the longitudinal axis X and that all of the applicator elements 18b are oriented in the same way relative to the longitudinal axis X is a direct consequence of the fact that the digital model is obtained by repetition of the reference applicator pattern 19r along the longitudinal axis.

As shown, the protuberances 22 are all of substantially identical shape, but this does not have to be the case.

The protuberances 22a and 22b extend from the body at the same height h and are symmetrical with one another relative to a median plane M. As can be seen in figure 19, the protuberances 22c extend from their base at a height on the body that is different to that of the protuberances 22a and 22b. The difference in height d on the body 20 of the protuberances 22c and 22a or 22b may be between 0 and 1.5 mm.

In the case where the applicator elements comprise several protuberances 22a, respectively 22b or 22c extending from the same side of the body, the latter may be identical and be connected to the body at different heights h along the latter. In the example shown, the protuberances 22a or 22b extending from the same side of the body 20 are spaced apart by a height h_a of between 0.05 and 2 mm, better still between 0.1 mm and 1 mm. The protuberances 22c extending from the same side of the body 20 are spaced apart by a height h_e of between 0.1 and 3 mm, preferably between 0.5 and 1 mm. The height h, is greater than the height h_a.

The axes of extension P of the protuberances 22a, 22b and 22c all make for example, as shown, an angle g with the axis of extension C of the body of between 45° and 135°, preferably other than 90°. In the example shown, the protuberances extend partially in the direction of the base of the corresponding applicator element 18a, the angle g being for example substantially equal to 65°.

Each applicator element 18a is symmetrical relative to a median plane M but this does not have to be the case.

Preferably, the applicator elements 18a comprise protuberances 22 extending over the upper half of the applicator element so as to constitute reserves of product at a height.

The applicator elements 18a define, by their distal ends, the envelope surface Si of the applicator member, shown in figure 3, in which the applicator member 18 is inscribed. The envelope surface Si is of substantially cylindrical shape, with the exception of its distal end which has a decreasing diameter.

The applicator elements 18b may define, by their distal ends, an additional envelope surface S2, shown in figure 16, inscribed within the envelope surface Si and having the same shape. The distance e between the additional envelope surface S2 and the envelope surface Si may be constant, in particular between 0 and 2 mm, for example substantially equal to 0.5 mm. Thus, the applicator elements 18b may be smaller than adjacent applicator elements 18a, the distance between the distal ends of adjacent applicator elements 18a and 18b, in projection along an axis transverse to the core 10, being equal to the distance e.

In this way, the distal ends of the applicator elements 18a define the distal ends of the applicator patterns 19.

In the embodiment described above, the protuberances 22 all have the same shape, but this does not have to be the case. For example, the protuberances 22c have a different shape to the protuberances 22a and 22b, in particular owing to their different orientations relative to the core.

In the example shown in figures 22 to 29, the reference applicator pattern 19r comprises two types of applicator elements: - an applicator element 18a comprising a body 20, two protuberances 22a and 22b extending laterally from the body 20, and an enlarged distal end 20b, and

- an applicator element 18b in the form of a spike.

The enlarged distal end 20b of each body 20, as shown in figure 25a, may be rounded, in particular in the form of a disc

The applicator elements 18a extend along axes of extension C which are all inclined relative to the radial axis R at their base, in particular by the same angle b. The axes of extension C may extend in a plane transverse to the longitudinal axis X or, preferably, be inclined relative to such a transverse plane.

The applicator elements 18b are all inclined relative to the radial axis R at their base, in particular by the same angle a. The applicator elements 18b may extend in a plane perpendicular to the longitudinal axis X or, preferably, be inclined relative to such a perpendicular plane.

In the example shown, the applicator elements 18a and 18b of the reference applicator pattern 19r are coplanar and make between them an angle d, visible in figure 28, of between 10 and 90°, better still between 25 and 45°.

Preferably, the distal end is flattened along a plane of symmetry Mo of the applicator element as shown in figure 25b, in such a way that it does not project laterally beyond the base. In this example, the applicator element is delimited in profile view by two parallel planes Mi; M2. The latter are spaced apart by a distance D which is smaller than or equal to the largest dimension of the base of the applicator element. However, the distal end 20b could be not flattened.

As shown in figure 25a, the length / of the enlarged distal part 22, measured along the axis of elongation C, is for example greater than or equal to 0.1 mm, better still 0.5 mm.

The ratio f/l , where l denotes the total height of the body 20, is for example between 15% and 50%.

The applicator elements 18a each comprise two protuberances 22a and 22b each extending along an axis of extension P contained in the same plane, in particular circumferentially to the core. The protuberances 22a and 22b extend on either side of the body 20. The protuberances 22a and 22b, as shown, are all of substantially identical shape. They have a constant cross section and a rounded distal end. As an alternative, the cross section may vary, in particular decreasing toward their distal end.

The protuberances 22a and 22b extend from the body at the same height h relative to the base of the body, being symmetrical to one another relative to the axis of extension C. As an alternative, the protuberances 22a and 22b extend from the body at different heights relative to the base of the body and/or are not symmetrical with one another relative to the axis of extension C.

The axes of extension P of the protuberances 22a and 22b each make an external angle g with the axis of extension C of the body of between 45° and 135°. In the example shown, the protuberances extend in the direction of the free end of the corresponding applicator element 18a, the angle g being substantially equal to 120°.

The applicator elements 18a comprise protuberances 22a; 22b extending over the distal half of the applicator element, in such a way as to constitute reserves of product at a distance from the core.

Preferably, each applicator element 18a is symmetrical relative to a median plane M, but this does not have to be the case.

In the example in question, as can be seen in particular in figures 26 to 28, the free ends of the applicator elements 18a define an envelope surface S I of the applicator member 8, the longitudinal axis of which is rectilinear and coincident with the longitudinal axis X of the core 10. The envelope S I has symmetry of revolution about this axis X, and in particular has the shape of a peanut, i.e. an elongate cylindrical shape narrowing at its center, as can be seen in particular in figure 16. The envelope surface S 1 has, in the example shown, a cross section that varies over the entire length of the applicator member 8, notably exhibiting three local minima, at points corresponding substantially to the distal end of the applicator member, to the middle of the length H of the applicator member 8 and to the proximal end of the applicator member.

The applicator elements 18b are substantially identical to the additional applicator elements described with reference to the second embodiment.

They differ from those described above in that the angle a is between 0° and 10°, for example substantially equal to 5°. In the embodiment shown in figures 30 to 33, the applicator member comprises two rows of applicator elements and the reference applicator patterns 19r of each of the rows comprise a single applicator element 18a and 18b, respectively. The reference applicator patterns 19r are different. The applicator elements 18a are in the form of a loop and the applicator elements 18b are in the form of spikes.

The applicator elements 18a extend from the core via two rectilinear feet 20a connected to one another at their distal ends by a rounded portion 20b. The rounded portion 20b has, on its surface oriented outward, reliefs 40 in the form of several bosses separated from one another by a recess. Such reliefs allow the formation of reserves of product.

The applicator elements 18a and 18b extend radially in a longitudinal plane of the core 10.

In this embodiment, the applicator elements 18a and 18b are not alternating within the helical rows. The applicator member 8 comprises two entwined helical rows, one of the rows being a row of applicator elements 18a in the form of a loop, as described above, and the other row being a row of applicator elements 18b in the form of spikes.

In the embodiment shown in figures 34 to 37, the applicator member comprises two rows of applicator elements and the reference applicator patterns 19r of each of the rows comprise a single applicator element 18a and 18b, respectively. The reference applicator patterns 19r are different. The applicator elements 18a are in the form of a loop and the applicator elements 18b are in the form of spikes.

The applicator elements 18a extend from the core via two feet 20a connected to one another at their distal ends by a rounded portion 20b, as shown in figure 31. The feet 20a are undulating but could, as an alternative, be rectilinear.

The applicator elements 18a extend in a transverse plane of the core 10.

In this embodiment, the applicator elements 18a and 18b are not alternating within the helical rows. The applicator member 8 comprises four entwined helical rows. Two of the rows are rows of applicator elements 18a in the form of loops as described above, extending over the strands of material 12 and 14 respectively from the core 10 between the grooves 16 and 17, and the two other rows are rows of applicator elements 18b in the form of spikes extending in the grooves 16 and 17 respectively, as shown figures 28 and 30. The invention is not limited to the embodiments described above. In particular, the shapes of applicator elements of the various embodiments may be combined with the various arrangements of applicator elements on the core described above.

The applicator elements may have shapes other than those described above.

For example, the applicator element may comprise one or more protuberances in the form of a spout oriented outward or toward the core and being connected to the core by flat, concave or convex surfaces, in the form of a triangle connected to the body by one of its edges, in the form of a boss of the body, in the form of a hook oriented toward the base or outward, in the form of a loop or in the form of a mushroom.

The applicator element may again have an enlarged distal end in the form of a half-disc. The enlarged distal end may be solid or hollow.

The applicator elements may take the form of teeth comprising or not comprising one or more projecting reliefs, spikes having one or more bends, in the form of a V or an X or having a V or an X at the end, or in the form of an open loop.

The applicator elements may be without an axis of symmetry.

In the examples shown, the applicator elements 18a of the applicator members are all of one or two types. The applicator member may comprise more than two different types of applicator elements.

The applicator member 8 may be produced using a device for production by additive manufacturing on the basis of a digital model of the applicator member 8.

The digital model faithfully represents the applicator member 8 in three dimensions, and may be generated using computer-assisted design software such as SolidWorks 3D.

As shown in figures 38a-f and 39, the production device 50 may comprise a printing substrate 51, a powdery material dispenser 53 for depositing a layer of powdery material 63 on the printing substrate 51, a first agent dispenser 55 for depositing one or more coalescence agents 65 on the layer of powdery material 63, a second agent dispenser 57 for supplying one or more coalescence modifying agents 67 and a source of energy 59.

During production, the powdery material dispenser 53 deposits a first layer of powdery material 63 over the whole surface of the printing substrate 51 as shown in figure 38a, moving the material dispenser 53 along the axis Yd. One or more coalescence agents 65 and/or coalescence modifiers 67 are then deposited on the parts of the layer 63, as shown in figure 38a, by moving the associated dispensers along the axis Yd. The parts of the layer 63 on which the agents 65 and the modifiers 67 are deposited are determined according to the digital model created beforehand.

Once the coalescence agents 65 and coalescence modifiers 67 have been deposited, they penetrate the layer 63 at least partially, as can be seen in figure 38b. Finally, energy is applied to the whole of the layer 63 using the source 51. Applying this energy causes at least partial fusion of the parts on which the coalescence agent or agents 65 have been applied, thus allowing, once the layer has cooled, the fused parts to solidify as shown in figure 38c. The modifiers 67 make it possible to obtain distinct edges of the fused zones by preventing fusion of the peripheral zones. After the layer of material 63 has been treated, as described above, a new layer 73 of powdery material is deposited on the layer 63 treated previously, as shown in figure 38d. The process explained above may then be repeated to generate the three-dimensional applicator member layer by layer as shown in figures 38d-f.

During production, the substrate 51 moves along the axis z in such a way that, as new layers of material are deposited, a predefined gap is maintained between the surface of the layer deposited most recently and the dispensers 55 and 57. As an alternative, the substrate 51 does not move along the axis z and the dispensers 55 and 57 may move along this axis.

Preferably, the applicator member 8 is produced by means of this device from its proximal end, i.e. the free end of the end piece 9 intended to be attached to the stem 7, to its distal end 11. The reverse is also possible.

Such a production method, suitable for making the applicator, is described in particular in international application W02015106816.

As an alternative, the applicator member 8 is produced using a different device for production by additive manufacturing, in particular by light irradiation of a photo- crosslinkable material, as shown in figures 40 and 41. In the example in question, the production device may comprise a light source 40, a vat 42 arranged above the light source 40 and a substrate 46. The vat 42 is at least partially transparent to the radiation emitted by the light source. It contains a liquid photo-crosslinkable material 44.

During production, the light source 40 is operated in accordance with the digital model to crosslink the liquid material 44 in a build zone between the substrate 46 and the plate 42, following a pattern dependant on the digital model. The crosslinked parts of the liquid material 44 are solid. Before production, as shown in figure 40, the substrate 46 is immersed in the liquid material 44 and the build zone is in contact with the substrate 46, in such a way that the liquid material 44 is crosslinked on the substrate 46, becoming attached to the latter. During production, as shown in figure 41, the substrate 46 is moved away from the light source 40 at the speed of production of the applicator member 8, such that the crosslinked parts are produced in successive layers, each crosslinked layer becoming attached to the one before.

The vat 42 may have a surface 48 between the substrate 46 and the light source 40 which is in fluidic communication with a source of polymerization inhibitor, in particular a source of oxygen. The polymerization inhibitor allows the liquid material 44 to be maintained in liquid form, by preventing its polymerization by the light irradiation, in a fluid zone of thickness not equal to zero. This fluid zone extends from the surface 48 to the build zone and allows the liquid to flow toward the build zone. Preferably, the fluid zone has a height of between 10 pm and 100 pm.

It may be that the interface between the fluid zone and the build zone is not distinct but may be formed with a polymerization gradient. In that case, the substrate 46 is moved continuously and the irradiation by the light source 40 is continuous.

Preferably, the applicator member 8 is produced using this device, from its proximal end 13 to its distal end 11. The reverse is also possible.

After the applicator member 8 has been produced, it is detached from the substrate 46 and heated to harden and smooth out the structure.

Such a production method, suitable for making the applicator, is described in particular in international applications WO2014126830 and WO2014126837.

As an alternative, the applicator member 8 is produced using a different device for production by additive manufacturing, notably by filament deposition printing (FDM), stereolithography (SLA) or Selective Laser Sintering (SLS).

The invention is not limited to the exemplary embodiments described above.

The device may comprise a reservoir of product and the applicator may be mounted by its proximal end corresponding to the free end of the end piece 9 on the reservoir. In this case, the applicator has a hollow core and at least one opening for supplying the applicator with cosmetic product.

Claims

1. A method for generating, using a computer-assisted design tool, a digital model of an applicator member, the applicator member comprising a core (10) that is elongate along a longitudinal axis (X) and at least one row of applicator patterns (19), the applicator patterns (19) each comprising one or more applicator elements (18, 18a; 18b) the method comprising the following steps, implemented by computer in the computer-assisted design tool:

(i) calculating at least one curve of intersection (32) between a helical surface (30) that is coaxial with the longitudinal axis (X) of the core and an envelope surface (S, S I) of the applicator member (8),

(ii) calculating a plurality of applicator patterns (19) of the row, each applicator pattern (19) being a replica, at a given position along the longitudinal axis of the core, of a predefined reference applicator pattern (19r) having at least been moved helically following the helical surface (30) from a reference position to the given position along the longitudinal axis (X) of the core in such a way that its distal end (20d) follows the curve of intersection (32), the reference applicator pattern (19r) extending within a volume delimited by the envelope surface (S) of the applicator member and having its distal end (20d) on the curve of intersection (32), and

(iii) recording the digital model thus generated in a computer memory.

2. The method as claimed in claim 1, comprising a step of calculating an external surface of the core (10) of the applicator member, the applicator pattern, preferably, being such that the applicator element or elements (18, 18a; 18b) of the applicator patterns (19) extend from the surface of the core.

3. The method as claimed in any one of the preceding claims, wherein the applicator member (8) comprises at least two rows of applicator patterns (19), step (i) comprising calculating at least two curves of intersection (32) each defined by the intersection between a helical surface (30) that is coaxial with the longitudinal axis (X) of the core and the envelope surface, step (ii) comprising calculating an applicator pattern (19) for each row, each applicator pattern (19) being a replica, at a given position along the longitudinal axis of the core, of a predefined reference applicator pattern (19r) of said row having been moved helically following the corresponding helical surface (30) from a reference position to the given position along the longitudinal axis (X) of the core in such a way that its distal end (20d) follows the corresponding curve of intersection (32), the reference applicator pattern (19r) of each row extending within the envelope surface (S) of the applicator member and having its distal end (20d) on the corresponding curve of intersection (32).

4. The method as claimed in claim 3, wherein the reference applicator patterns (19r) of at least two of the rows are of identical shape.

5. The method as claimed in claim 3, wherein the reference applicator patterns (19r) of at least two rows are of different shapes, the reference applicator pattern (19r) of one row preferably consisting of an applicator element in the form of a spike (18b) and the reference applicator pattern (19r) of another row preferably consisting of an applicator element (18a) comprising a body (20) and preferably at least one protuberance (22, 22a, 22b, 22c) extending from the body, or the body being in the form of a loop.

6. The method as claimed in any one of the preceding claims, wherein the helical surface or surfaces (30) form(s), around the longitudinal axis of the core, at least one turn, better still a plurality of turns, in particular between 32 and 60 turns, better still between 3 and 40 turns, over the entire length of the applicator member.

7. The method as claimed in any one of the preceding claims, wherein the reference applicator pattern (19r) of the or of at least one row, preferably of each row, comprises a plurality of applicator elements (18, 18a; 18b), in particular two applicator elements.

8. The method as claimed in claim 10, wherein at least two of the applicator elements (18a; 18b) of the reference applicator pattern (19r) of the or of at least one row are different, in particular one of the applicator elements (18b) is a spike and another of the applicator elements (18a) comprises a body (20) and at least one protuberance (22, 22a, 22b, 22c) extending from the body or the body being in the form of a loop.

9. The method as claimed in any one of claims 1 to 6, wherein the reference applicator pattern (19r) of the or of at least one row, better still of each row, comprises a single applicator element (18, 18a; 18b).

10. The method as claimed in any one of the preceding claims, wherein the applicator element or at least one of the applicator elements (18, 18a; 18b), better still each applicator element, of the reference applicator pattern of the or of at least one row, better