FR2891707A1 - Seal for lid of cosmetic product container has two inner lips that converge to grip container ring when pressed in place - Google Patents

Abstract

The lid seal, designed to engage with the rim (23) of a container (20) of a cosmetic product, typically a gel, powder, foam or cream with an ingredient that is volatile or sensitive to air, has inner (31) and outer (32) lips on either side of a recess (33) the same shape as the rim. When the lid is fitted and the seal is pressed against the container rim the two lips converge to grip the rim and seal it. The seal recess has a width slightly greater than the thickness of the rim and a depth equivalent to at least half the thickness.

Description

PINCEMENT JOINT FOR SEALED CASES TECHNICAL FIELD s The invention

  relates to the field of housings for cosmetic products, typically makeup products, having a bottom and a lid, said cover and said bottom being provided with complementary closure means. It relates more particularly to cases with tight closure. STATE OF THE ART Cosmetic products, in particular for makeup and skin care, often contain volatile compounds which guarantee a certain smoothness on application but which evaporate very quickly on contact with the open air. to leave a dry extract on the skin. Other products, packaged in a similar fashion, may also contain air sensitive compounds. All these products require to be packaged in perfectly airtight cases under penalty of seeing their state deteriorate rapidly and become either aesthetically unacceptable (dried product in the bottom of the bucket) or unusable.

  In general, the housings comprise a hollow lid, typically provided with an inner mirror, and a hollow base, typically provided with a grid or intermediate support of one or more cups for receiving said cosmetic product. Said buckets can be replaced by refills, which allows the user to pay only the replacement of the consumed product while continuing to use said housing. A refill is generally in the form of a tank - or scoop - containing said cosmetic product which is in the form of a gel, a mousse, a cream or, more generally, powder, compacted or not. The so-called "waterproof" boxes, usually used for these products, contain refills designed to guarantee an airtight closure around the product. These refills are often "sleevées" that is to say surrounded by a sleeve - usually thermoformed and / or heat shrunk - or covered with a lid - usually heat sealed - after packaging to ensure good product preservation until 'at first use by the consumer.

  In order to solve these sealing problems, most of the makeup products comprising volatile components have most often been packaged in cylindrical containers with circular, elliptical or oval orthogonal cross sections, called "sticks". With this type of container, it is easy to achieve a good seal by diametral interference between the cover and the body, that is to say by forcibly engaging a cylindrical side wall of the 1s cap around a cylindrical wall of the body , the diameter at rest of the cylindrical wall of the hood being slightly less than the diameter at rest of the cylindrical wall of the body. Some housings use the same diametric interference sealing system as the sticks, but given the large diameters of the buckets, the diametric interference necessary to ensure the seal is often very strong, which involves great efforts of closure and opening of the housings. In the latter case, the parts concerned by the sealing must necessarily have a shape close to a circle, a low eccentricity ellipse or a flattened oval to ensure a good uniformity of the diametric interference - that the It can also be called lateral - all around the sealing zone.

  However, the diametral - or lateral - interference which permits a watertight closure not only requires a force high enough to close the container (this force is certainly easily reached by pressing on the lid) but also a high force to open it, which may be inconvenient for the user, because the application of such a force can -3 cause a sudden opening of the housing with the risk of projection of elements contained within said housing.

  To overcome the strong diametral interference, the French patent application FR 2 803 993 recommends the use of flexible lips attached to the cover and the other to the housing, cooperating with each other in a sealed manner in tangential junction so that the both of these lips are flexed when the housing is closed. These lips make it possible to reduce the force required for opening and closing the lid, but such a solution is only applicable to substantially circular pieces - that is to say having a circle-shaped section. ellipse with low eccentricity or slightly elongated oval - otherwise the level of tightness is poor. In general, and more particularly for buckets having no substantially circular shape, generally used flat seals, reported or overmolded in the lids of the refills, and they are associated with a closure system that ensures a high pressure on the joint. Thus, the French patent application FR 2 788 255 proposes a housing cover provided with a seal which has at least one flexible lip protruding so as to define, in the closed position of said housing, at least one zone of sealing along the outer face of the wall at the periphery of the housing compartment. The French application FR 2 819 159 proposes a similar principle but by limiting the seal to the assembly constituted by the bucket and an auxiliary lid which bears on said bucket.

  When the bucket is not circular, it is very difficult, given the large area required for the use of the product block and the flexibility of certain parts of the housing that results, to guarantee a homogeneous pressure. over the entire usable area of the joint. This may result in a lack of adhesion of the seal in certain parts of the casing, the latter no longer playing the intended role, which is to prevent the evaporation of volatile products and thus prevent degradation of the cosmetic product. In order to seal the entire useful surface of the seal, complex housing structures that are difficult to make and expensive to make must be designed. Thus, the French patent application FR 2,833,144 describes a sealed casing slides, where an auxiliary cover is guided in translation from a closed position to an open position, said slides, associated with lugs integral with the auxiliary lid w , to better distribute the compression force on the seal over the entire length of the lid and not only at the hinge and the clasp.

  The object of the invention is to provide a casing for products with volatile components which does not have the drawbacks mentioned above and which allows the application of a homogeneous pressure of the seal over its entire useful surface, whatever the shape of the bucket. employed and without resorting to an effort of opening and closing too important. DESCRIPTION OF THE INVENTION A first object according to the invention is a cosmetic container comprising a vessel and a lid, said vessel having a bottom and a side wall, said lid being provided with a seal typically located at the periphery. said cover, characterized in that said seal comprises at least one substantially axial inner lip and a substantially axial outer lip which surround a cavity intended to receive the upper edge of said side wall of the tank, said seal being designed so that when said upper edge of the side wall of the tank comes into contact with the bottom of said cavity by transmitting on the seal the axial closing force, the ends of the inner and outer lips undergo a lateral displacement respectively centrifugal and centripetal so that both come into contact with said side wall of the vessel.

  s To ensure a perfect airtightness, it is necessary to have a sealing means on the entire perimeter of the junction between the tank and the lid. This is why the seal is advantageously in the form of a closed contour, typically located at the periphery of said lid to benefit from the flexibility of the latter. The seal according to the invention comprises an inner lip and an outer lip which are substantially axial, that is to say which are oriented substantially in the direction of application of the closing force, which itself is in perpendicular to the bottom of the tank. Preferably, the seal has a constant section over its entire length and follows a closed contour whose shape at rest corresponds to the general shape 1s of the upper edge of the side wall of the vessel. The latter being generally plane, the inner and outer lips, substantially axial, are oriented in a direction substantially perpendicular to the plane of the joint.

  These lips have significant heights relative to the thickness of the upper edge of the side wall of the vessel. They frame a cavity whose width is slightly greater than the thickness of the upper edge of the side wall of the tank and whose height is typically at least equal to half of said thickness. The seal according to the invention is designed such that when the bottom of said cavity is subjected to an axial compressive force, the ends of the inner and outer lips undergo a lateral displacement respectively centrifugal and centripetal so that they create a a kind of macro-pinching of said upper edge of the side wall of the tank with two contact zones obstructing the passage of air. The adjectives "centripetal" and "centrifugal" are here used in a general sense, going beyond a purely axisymmetric geometrical configuration and signifying "inwardly" and "outwardly", respectively.

  Preferably, the inner and outer lips have comparable flexibility and the displacement of their ends has substantially the same amplitude. However, and particularly for containers of small size, the outer lip, less flexible than the inner lip, has an end which, without the application of the closing force, is already close to the side wall and the pinching is essentially by centrifugal displacement of the end of the inner lip.

  The invention makes it possible, on the one hand, to overcome the problems of manufacturing dimensional tolerances associated with a diametrical or lateral interference aimed at. It allows the other hand, the pressure force exerted flat on the seal being converted into a lateral force acting on the ends of the joint, to overcome the problems of flatness encountered in the housings of the prior art 1s. Indeed, even if, locally, the upper edge of the side wall does not come into contact with the bottom of the cavity, the overall deformation of the seal allows a pinch which also ensures, at this location, two sealing zones . The invention also makes it possible to instantly eliminate any diametrical interference as soon as the casing is unlocked, which, in fact, makes it possible to have a very low opening force.

  The examples given below show different sections of joint to obtain the desired effect. These seals are adapted to different embodiments and to different possible applications. Their sections are based on the same principle: the bottom of the cavity is easily sinking under the effect of the axial force and its axial displacement causes a flexion of the seal resulting in a pinching of the inner and outer lips. The profile of the section of the seal and that of the end of the edge of the side wall can be studied so as to favor the best contact conditions as a function of the position of the targeted contact zone: presence of gadroons on the parts opposite the ends of the lips, end of the edge and rounded cavity bottom allowing -7 a greater contact area under the direct effect of the axial closing force, ... The container for cosmetic product according to the invention may be a refill of makeup product and / or a case cup. As a refill, this container should be equipped with an overpack that maintains pressure on the lid. As a bucket, the tank can be placed in the bottom of the housing, and the lid is placed so that it undergoes an axial closing force through either the main housing cover or a lid ~ o secondary (axial interference).

  Preferably, the tank is made of a material which is a barrier to the diffusion of the volatile product concerned. For example, if it is water, the tank will preferably polypropylene, if it is silicone (cyclométhycone), the 1s tank will preferably polypropylene (PP) or acrylobutadiène styrene (ABS and if it is isododecane, the vessel will preferably be made of polystyrene acrylonitrile (SAN).

  The seal is made of a flexible material adapted to the volatile compound, for example an elastomeric polymer of the styrene-ethylene-butadiene-styrene copolymer type (SEBS) or a silicone, preferably a two-component silicone (two components which react when they are Implementation).

  The lid may be of any material if the gasket covers it completely. Otherwise, a material similar to that of the tank, preferably a little more rigid, will be aimed at preserving the geometry of the lid, and therefore that of the seal, under the effect of the forces generated during the openings and closures of said container.

  The invention also relates to a housing for the packaging of a cosmetic product for facials, typically in the form of gel, powder, pressed or not, foam or cream, said product comprising a volatile compound or sensitive to air, said housing comprising a lid generally provided with an inner mirror and a base provided with an intermediate support of at least one cup for receiving said cosmetic product, characterized in that said cup is a container such as the one previously defined. FIGS. FIG. 1 a diagrammatically illustrates, in front view, a section of a container according to the invention with a first type of seal, before application of the closing force. Figure 1b schematically illustrates, in front view, a section of the same 1s container during the application of the closing force. 2 schematically illustrates, in front view, a section of a similar container with a variant of the same type of seal, before application of the closing force. Figures 3a and 3b detail, respectively before and during the application of the closing force, the sections in front view of a second type of seal and the upper edge of the side wall of the container. Figure 4 schematically illustrates, during the application of the closing force, the section in front view of a third type of seal on the upper edge of the side wall of the container. FIG. 5 schematically illustrates, during the application of the closing force, the section in front view of a fourth type of saddle joint on the upper edge of the side wall of the container. Figures 6a and 6b schematically illustrate, respectively before and during the application of the closing force, the front view sections of a fifth type of seal and the top edge of the side wall of the container.

  Figures 7a and 7b schematically illustrate, respectively before and during the application of the closing force, the sections in front view of a sixth type of seal and the upper edge of the side wall of the container.

EXAMPLE 1 (Figures la and lb)

  The container 1 of this example is a refill for a cosmetic product comprising a tank 20 and a lid 10. The tank has a bottom 21 and a side wall 22. The cover 10 is provided with a seal 30 which forms a closed contour at the periphery of the lid.

  The seal 30 comprises a substantially axial inner lip 31 and an outer lip 32 substantially axial which surround a cavity 33 intended to receive the upper edge 23 of the side wall 22 of the tank 20. The seal 30 1s is designed so that when the upper edge 23 of the side wall 22 of the tank comes into contact with the bottom 330 of the cavity 33 by transmitting on the seal the axial closing force F, the ends of the inner and outer lips 320 and 320 respectively undergo lateral displacement centrifugal (E) and centripetal (I) so that both come into contact with the side wall 22 of the tank 20.

  The seal 30 is of a material adapted to the nature of the packaged cosmetic product. It must in particular have good barrier properties vis-à-vis the volatile component it contains. Depending on the material used, the seal may be an elastomeric thermoplastic extruded or injected, an elastomer injected and baked or silicone, preferably injected in two-component.

  Once placed on the lid, the seal 30 follows a plane closed peripheral contour. The inner lip 31 and the outer lip 32 are substantially axial, that is, oriented substantially in the direction of application of the closing force, perpendicular to the bottom 21 of the tank and the plane of the joint. The cavity 33 has a width which is slightly greater than the thickness of the upper edge 23 of the side wall 22 of the vessel and a height which is, in the present case, of the order of twice said thickness. When the bottom 330 of the cavity 33 is subjected to an axial compressive force F, the ends of the inner and outer lips 320 and 320 make a kind of macro-pinching of the upper edge 23 of the side wall 22 of the tank 20 with three or , especially in the event of a flatness defect, that is to say when the contact is not established at 43 between the upper edge 23 and the bottom of the cavity 33, at least two contact zones 41 and 42 which make obstacle to the passage of air.

  The inner and outer lips have comparable flexibility and the displacement of their ends has substantially the same amplitude.

  EXAMPLE 2 (FIG. 2) 1s The container of this example is a refill for a cosmetic product very similar to that presented in the previous example, with the difference that the seal is in the form of a molded elastomeric piece which comprises, in addition to the inner 31 and outer 32 lips, a central portion 34 20 and thus completely covers the cover 10. The cover may in this case be of any material, since the diffusion barrier opposed to the air is provided entirely by the joint and the tank, the latter must be made of a material exerting a suitable diffusion barrier.

EXAMPLE 3 (FIGS. 3a and 3b)

  The lid of the container of this example has a joint whose section has a small average thickness with respect to the height of the substantially axial lips, here typically less than one fifth of said height. The ends of the inner and outer lips have, on their opposite faces, gadroons 310 'and 320', whose smaller radius of curvature makes it possible to locate the contact zones 41 ', 42' more precisely, to reduce the area of contact and locally increase the normal stress in these areas. If, for reasons of unevenness, the contact is not established at 43 ', there remain at least two airtight contact zones at 41' and 42 '. EXAMPLE 4 (Figure 4)

  The container of this example is small. Its lid has a H-shaped sectional seal, one of the recesses of the H serving as a cavity for receiving the upper edge of the side wall of the vessel. The horizontal bar of the H, corresponding to the bottom of the cavity, is the thinnest part of the section of the seal and sinks easily under the effect of a vertical force, causing an opening of the branches of the H above said bar and a closure of said branches of H below. EXAMPLE 5 (FIG. 5)

  The container of this example is also small. Its lid has a joint whose section is as in the previous example, in the form of H but it is asymmetrical: the outer lip, generally thicker and less flexible than the inner lip, has an end which, without the application of the closing force, is already close to the side wall and almost to its contact. The pinching is effected essentially by centrifugal displacement of the end of the inner lip 52. EXAMPLE 6 (FIGS. 6a and 6b)

  The container lid of this example has an extruded thermoplastic elastomer seal, the section of which has an open cavity 63 -30 for surrounding and then pinching the upper edge of the side wall of the vessel - and an inner recess 65 near the bottom. of the cavity 63, making it easy to push away. Here again, when the closing force is exerted, the axial displacement of the bottom of the cavity causes a flexion of the seal which results in a rotation of the inner and outer lips and, consequently, by a centrifugal lateral displacement of the end of the inner lip and a centripetal lateral displacement of the end of the outer lip.

EXAMPLE 7 (FIGS. 7a and 7b)

  The lid of the container of this example has a seal 70 whose section ~ o has a substantially constant thickness, small relative to the height of the substantially axial lips, typically less than one fifth of said height. In this way, the bottom of the cavity can be deformed under the effect of the closing force by marrying the shape of the upper edge 73 of the side wall of the vessel. In this example, the latter has a rounded shape 15 which increases the contact surface perpendicular to the closing force.

Claims (11)

  Cosmetic container (1) comprising a vessel (20) and a lid (10), said vessel having a bottom (21) and a side wall (22), said lid being provided with a seal (30) typically placed at the periphery of said cover, characterized in that said seal comprises at least one substantially axial inner lip (31) and an essentially axial outer lip (32) which surround a cavity (33) intended to receive the upper edge (23) of said side wall of the tank, said seal being designed such that ~ o when said upper edge of the side wall of the tank comes into contact with the bottom (330) of said cavity by transmitting on the joint the axial force closure (F), the ends (310, 320) of the inner and outer lips undergo a respectively centrifugal (E) and centripetal (I) lateral displacement, so that both come into contact with said lateral wall of the 1s tank.   2) Container according to claim 1 characterized in that said seal follows a closed contour whose shape at rest corresponds to the general shape of the upper edge of the side wall of the vessel.   3) Container according to claim 1 or 2 characterized in that said cavity has a width slightly greater than the thickness of the upper edge (23) of the side wall (22) of the tank (20) and a height at least equal to half of said thickness. 25   4) Container according to any one of claims 1 to 3 wherein said inner (31) and outer (32) lips have comparable flexibility so that said centripetal and centrifugal lateral displacements of their ends (310, 320) - which result the application of closing force (F) - have substantially the same amplitude. 2014-   5) Container according to any one of claims 1 to 3 wherein the outer lip, less flexible than the inner lip, has an end which, without the application of the closing force, is already close to said side wall of the vessel and wherein the nip is effected essentially by centrifugal displacement of the end of the inner lip (52).   6) A container according to any one of claims 1 to 4, wherein said bottom (330) of the cavity (33) is easily sinking under the effect of the axial force ~ o (F) closing so that its axial displacement causes flexion of the seal (30) which results in pinching of the inner (31) and outer (32) lips on the upper edge (23) of said side wall, thereby creating at least two sealed contact areas (41); , 42). 1s   7) A container according to any one of claims 1 to 4, wherein the ends of said lips have on their faces vis-à-vis gadroons (310 ', 320'), whose lower radius of curvature can locate more precisely the contact areas (41 ', 42') with the side wall of the tank. 20   8) A container according to any one of claims 1 to 4, wherein the section of said seal (70) has a thickness less than one fifth of the height of the substantially axial lips, and wherein the upper edge (73) of the side wall of the tank has a rounded shape. 25   9) A container according to any one of claims 1 to 8, wherein said vessel is made of a material which is a barrier to the diffusion of the volatile product contained in the cosmetic product thus packaged.   A container according to any of claims 1 to 9, wherein said seal is a part which comprises, in addition to the inner (31) and outer (32) lips, a central portion (34), the overlying assembly entirely the lid and being made of a material which is a barrier to the diffusion of the volatile product contained in the cosmetic product thus conditioned.   11) Box for packaging a cosmetic product for facials, typically in the form of gel, powder, pressed or not, foam or cream, said product comprising a volatile or air-sensitive compound, said housing comprising a lid generally provided with an inner mirror and a base provided with an intermediate support of at least one cup for receiving said cosmetic product, characterized in that ~ o said cup is a container according to any one of Claims 1 to 10.