Cosmetic product packaging assembly with closure mechanism
The cosmetic product packaging assembly addresses stress cracking and manufacturing challenges by using a notch on the neck and offset sealing skirt, ensuring a reliable seal and recyclability, particularly with PET materials.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- LOREAL SA
- Filing Date
- 2024-12-16
- Publication Date
- 2026-06-19
AI Technical Summary
Cosmetic product packaging assemblies experience high failure rates due to stress cracking at the neck area, leading to leaks, especially when using materials like polyethylene terephthalate (PET) and containing alcohol or higher branched alkanes, and are difficult to manufacture with complex mold designs.
A cosmetic product packaging assembly with a notch on the inner surface of the neck and a sealing skirt that is offset from the rim, allowing for a clamping contact away from the fragile rim area, using PET for both the container and closure, and a simple manufacturing process.
Reduces stress cracking and manufacturing complexity while ensuring a reliable seal and improved recyclability, with PET being widely recyclable and transparent for product visibility.
Smart Images
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Abstract
Description
Title of the invention: Cosmetic product packaging assembly with a closing mechanism
[0001] The present invention relates to a cosmetic product packaging assembly, comprising:
[0002] - a container having a principal axis defining an axial direction, the a container having a neck defining an opening, the neck comprising:
[0003] an interior surface,
[0004] an external surface bearing fastening elements, and
[0005] a drinking joint connecting the inner surface and the outer surface;
[0006] - a closing element adapted to cooperate with the neck to seal the container and including:
[0007] a sealing plate adapted to extend transversely across the opening of the container,
[0008] a fastening skirt carrying additional fastening elements, the additional elements being complementary to the fastening elements of the neck so as to secure the closure element to the neck of the container, and
[0009] a sealing skirt, the sealing skirt extending inside the fixing skirt in a radial direction, the sealing skirt extending perpendicularly to the sealing plate.
[0010] Packaging device means any packaging which allows the sale, transport, protection and storage of the product it contains.
[0011] A cosmetic product is advantageously a product as defined in Regulation (EC) No 1223 / 2009 of the European Parliament and of the Council of 30 November 2009 on cosmetic products.
[0012] The product contained in the device according to the invention is, for example, a makeup product, such as a foundation, a makeup removal product, such as micellar water, a hygiene product, in particular for the body or hair, or even a cream or serum for the surface of the epidermis.
[0013] Such a conditioning assembly is known, in which the inner surface of the neck has an axial upper portion extending from the rim, the sealing skirt being in tight contact with said upper portion from the rim.
[0014] The clamping contact is intended to create a seal between the neck of the container and the closing element, so that the container is sealed in a hermetic manner.
[0015] However, on a significant proportion of containers, the occurrence of a stress cracking phenomenon is observed at the neck of the container in the area of tight contact with the closing device.
[0016] Such cracking corresponds to the appearance of cracks extending from one side of the drinking tube to the other. This is then likely to lead to a sealing problem. In particular, the more fluid the cosmetic product packaged as a whole is, the more likely it is to leak through these cracks.
[0017] On a typical model, for example, approximately 70% of packaging assemblies are found to be defective with regard to sealing, due to stress cracking.
[0018] One solution to this problem is to provide a sealing skirt whose external face is convex or has a ridge at the level of a free end of said skirt to achieve sealing with the internal surface of the neck.
[0019] However, a closing element with such a sealing skirt has the disadvantage of being more complicated to manufacture, in particular to mold by injection, because it requires a complex sequence of mold element movements for demolding, the external skirt having undercut elements by its convex external face or its bead which requires first clearing a central core before this undercut element can be forcibly demolded.
[0020] The proposal of eco-responsible, environmentally friendly solutions whose design and development take into account environmental issues is becoming a major concern in order to contribute to meeting planetary challenges.
[0021] It is therefore essential to design more durable products, thereby reducing the amount of materials used and / or replacing them with more environmentally friendly materials and / or using recyclable materials in order to reduce the carbon footprint of the product.
[0022] In this context, it is important to offer recyclable packaging containing in particular separable elements and / or made of a minimum of materials and / or free from materials that are difficult to recycle in order to facilitate their end of life.
[0023] Thus, it is necessary to develop packaging made of environmentally friendly recyclable materials to allow for the recovery of packaging at the end of its life and to avoid pollution of recycling channels.
[0024] The aim of the invention is therefore to propose a cosmetic product packaging assembly, preserving the integrity and reliability of the airtight assembly between the container and the closure element, while offering the possibility of providing better recyclability of the device and simple manufacturing.
[0025] To this end, the invention relates to an assembly as described above, in which the inner surface of the neck comprises an upper portion extending from the rim and a clamping portion extending from the upper portion and away from the rim in the axial direction,
[0026] in which the upper portion of the inner surface of the neck comprises a notch, the notch comprising an axial segment extending from the rim over a length and a segment with a radial component connecting the axial segment to the clamping portion of the inner surface of the neck,
[0027] and in which the sealing skirt of the closing member is configured to be in tight contact with the inner surface of the neck in an axial portion included in the clamping portion of the inner surface of the neck, when the closing member cooperates with the neck.
[0028] The step or offset allows the clamping contact to be moved away from the rim by at least the dimension of the axial segment along the axial direction. This limits the forces applied to the neck near the rim, which is a relatively fragile area, including those susceptible to stress cracking, and / or, for example, in the event of any geometric defects in the skirt, such as ovalization.
[0029] Adding the step in the usual model mentioned in the introduction makes it possible to go from about 70% of packaging assemblies considered defective with regard to sealing to 0%.
[0030] This also allows the contact area of the sealing skirt on the neck of the bottle to be moved to a more flexible area than at the foot of the skirt, in its connection area to the tray, which is a very rigid area of the closure element.
[0031] This offers, for example, the possibility of using a copolyester material for the container, and in particular polyethylene terephthalate (PET), which is a material that is particularly well recycled worldwide, but is subject to the stress cracking phenomenon described above, especially when the cosmetic product contained in the container contains alcohol or a higher branched alkane, such as isododecane. With a clamping zone located at the rim, this is likely to cause the free edge of the neck to flare out, possibly resulting in the appearance of crack(s).Thus, by providing a tight contact between the neck of the container and the skirt of the closure, offset axially away from the rim of the neck by the presence of the notch, the radial clamping forces are exerted on the neck away from the relatively fragile area, which is located near the rim, which greatly reduces the risk of flare, and thus of cracking, including when the container is made of a copolyester material, for example PET and when the cosmetic product contained in the container contains alcohol or a higher branched alkane, such as isododecane.
[0032] This also offers the possibility of using the same material, for example PET, for both the container and the closure. Using the same material facilitates recycling. However, by using the same material, the closure material does not have additional resilience compared to the neck, so it does not absorb the radial clamping force between the closure and the neck to ensure a reliable and leak-proof seal between these components. This radial force is then transmitted to the neck. With a clamping zone located at the rim, this is likely to cause the free edge to flare, possibly resulting in the appearance of crack(s).Thus, by providing a clamping contact offset by the presence of the notch, the radial clamping forces are exerted on the neck away from the relatively fragile area, which is located near the rim, which greatly reduces the risk of flare, and thus of cracking, including when the closure element and the container are made of the same material, for example PET, which is a material that is particularly well recycled worldwide.
[0033] Moreover, the sealing skirt of such an assembly is not complex to manufacture, in particular because it has an overall cylindrical shape, without undercut portion.
[0034] Finally, when the container is manufactured by injection blow molding, this helps to limit the influence of venting or cavity filling defects in the mold during the injection blow molding process. These defects, occurring during the injection of the preform, are likely to be more prevalent on the neck, and particularly at the neck opening, than in other areas of the preform. Indeed, a preform manufactured by injection molding and intended to be subsequently blow molded typically has a neck and a tubular portion extending from the neck and defining a base. The injection point of such a preform during its injection molding is located on the base of the tubular portion of the preform, opposite the neck.Thus, during the injection of the preform material into the cavity, the air present in the injection mold cavity is evacuated from the bottom of the cavity, near the injection point, towards the cavity area defining the neck of the preform. Furthermore, the preform material from the injection die has an optimal temperature at the injection point, and this temperature gradually decreases as the material travels through the mold cavity until it reaches the cavity area defining the neck of the preform. This area is therefore the most susceptible to defects, sometimes invisible and consisting, for example, of residual internal stresses, due to imperfect air venting / evacuation or a suboptimal material temperature, leading to a risk of injection molding defects, such as microbubbles, and / or impacting the isotropy of the material. mechanical characteristics of the preform at the level of its neck, and in particular of the neck opening.
[0035] According to other advantageous aspects of the invention, the assembly comprises one or more of the following features, taken individually or in all technically possible combinations:
[0036] - the axial segment is connected to the rim and / or to the radial component segment by via a chamfer or fillet, and / or the radial component segment is connected to the clamping portion of the inner surface of the neck via a chamfer or fillet;
[0037] This is particularly advantageous in terms of centering and / or progressive tensioning of the sealing skirt during the assembly of the container and the closing element.
[0038] - the container is made of copolyester material, in particular a semi- aromatic, such as polyethylene terephthalate, and the closing element is, in particular, made of the same copolyester material, and more particularly of polyethylene terephthalate;
[0039] This improves the recyclability of the container itself. Indeed, PET is a material that is easily and widely recyclable. Furthermore, PET has a Young's modulus greater than 1.5 GPa, is transparent, and is strong enough to form a container for the cosmetic product, which maintains its shape with a standard thickness (except in the case of a deformable portion specifically designed to deform).
[0040] When the container and the closure element are both made of the same copolyester material, in particular PET, the recyclability of the packaging device as such is improved; indeed, since the closure element and the container are made of the same material, these two constituent elements of the packaging assembly can be placed in the same recycling stream, in particular without requiring prior disassembly.
[0041] Finally, the use of PET to form the container and possibly the closure mechanism is particularly advantageous because this material is compatible with a wide range of cosmetic products intended to be contained within the container. Since PET is transparent, it also allows the consumer to see the cosmetic product inside the container, a characteristic that is a marketing advantage for promoting the cleanliness of certain cosmetic products, such as micellar waters.
[0042] - the axial segment of the step has a height measured along the direction axial greater than or equal to 0.3 mm, preferably greater than or equal to 0.5 mm, preferably greater than or equal to 0.7 mm, for example between 0.4 mm and 2 mm;
[0043] Such an axial distance is advantageous for reducing the radial forces applied to the relatively fragile area located near the rim, by moving the tight contact of the rim away from the neck sensitive to cracking.
[0044] - the axial segment of the step has a height measured along the direction axial, and the neck has a thickness measured between the clamping portion of the inner surface and the outer surface, and the ratio of height to thickness is between 1 / 4 and 1 / 2;
[0045] Such a distance is advantageous for reducing the radial forces applied to the relatively fragile area located near the drinking hole, depending on the thickness of said area.
[0046] - the segment with a radial component has a radial dimension greater than or equal to to 0.1 mm, preferably greater than or equal to 0.15 mm, preferably greater than or equal to 0.2 mm;
[0047] Such a radial distance makes it possible to ensure that there is no radial contact between the sealing skirt and the inner surface of the neck in the vicinity of the rim, a non-zero clearance being maintained between these elements in this area, while ensuring centering of the closure member relative to the neck when the sealing skirt is inserted.
[0048] - the segment with a radial component has a radial dimension, and the neck has a thickness measured between the clamping portion of the inner surface and the outer surface, and the ratio of the radial dimension to the thickness is between 1 / 20 and 1 / 5;
[0049] Such a distance is particularly advantageous for reducing the radial forces applied to the relatively fragile area located near the drinking hole, depending on the thickness of said area.
[0050] - the drinking vessel comprises a radial portion, the radial portion forming an end free of the neck, the radial portion having a radial dimension greater than or equal to 0.4 mm, in particular greater than or equal to 0.6 mm, in particular greater than or equal to 0.8 mm, and in particular greater than or equal to 1 mm;
[0051] Such a thickness of rim allows for a rim that is more resistant to stress cracking, allowing for better distribution of the axial stop contact forces with the sealing element, and limiting the influence of venting or filling defects of the mold cavity during the injection of a preform to form the container, which are more present at the rim.
[0052] - the axial segment of the step has a height measured along the direction axial, the segment with radial component having a radial dimension, the ratio of the height of the axial segment to the radial dimension of the segment with radial component being greater than or equal to 2, preferably greater than or equal to 3;
[0053] Such a ratio is particularly advantageous for limiting the transmission of stresses from the tight contact to the area near the rim of the neck.
[0054] - the inner surface of the neck presents, in the axial portion of the clamping portion, a smaller diameter, preferably strictly smaller, than the outer diameter of the sealing skirt adapted to cooperate with the clamping portion when the closing member cooperates with the neck by a distance called radial interference, the radial interference being preferably greater than or equal to 0.05 mm, preferably greater than or equal to 0.1 mm, preferably greater than or equal to 0.15 mm, preferably greater than or equal to 0.2 mm; and / or
[0055] Such a distance is particularly advantageous for ensuring the sealing of the assembly when the closing member cooperates with the neck.
[0056] - the axial segment of the step has a height measured along the direction axial, the ratio of radial interference to the height of the axial segment being less than or equal to 0.33, preferably less than or equal to 0.25, preferably less than or equal to 0.2.
[0057] Such a ratio is particularly advantageous, so that the more the clamping contact exerts a stress force, the further it is placed from the rim of the neck, i.e. the particularly sensitive area, to avoid stress cracking at the rim.
[0058] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:
[0059] [Fig-1] [Fig.1] is a partial cross-sectional view of an assembly according to an example of method of embodiment of the invention,
[0060] [Fig.2] [Fig.2] is an enlarged view of area A of [Fig.1].
[0061] An example of assembly 10 of cosmetic product packaging according to the invention is partially shown in Figures 1 and 2.
[0062] The assembly 10 comprises a container 12 and a closing member 14.
[0063] The container 12 is, for example, made of a copolyester material, more particularly of polyethylene terephthalate (PET), more particularly recycled or not.
[0064] Container 12 is, for example, a bottle.
[0065] Container 12 is suitable for containing the cosmetic product in a receiving volume.
[0066] The container 12 has a principal axis X defining an axial direction.
[0067] The term "radially" or "along a radial direction" is further defined according to the usual direction in relation to this main axis X.
[0068] The container 12 has a neck 16 defining an opening 18.
[0069] The opening 18 allows the passage of cosmetic product, in particular the removal of cosmetic product from container 10 into the receiving volume or the refilling of container 12 with cosmetic product. The opening 18 also allows the passage of the filling tube during the packaging and filling of container 12 with cosmetic product.
[0070] The neck 16 comprises an inner surface 20, an outer surface 22, and a drinking hole 24 connecting the inner surface 20 and the outer surface 22.
[0071] The drinking hole 24 forms a free end of the neck 16 along the axial direction.
[0072] The outer surface 22 carries fastening elements 26 for a closing mechanism, as described below.
[0073] The fastening elements 26 include, for example, a thread or portions of a thread, to allow the screwing of said closing member at the neck.
[0074] The inner surface 20 has, for example, a rotational symmetry about the principal axis X.
[0075] Here, the collar 16 exhibits rotational symmetry around the principal axis X, with the possible exception of the fixing elements 26.
[0076] The inner surface 20 comprises an upper portion 28 extending from the rim 24 and a clamping portion 30 extending from the upper portion and away from the rim 24 in the axial direction.
[0077] The inner surface 20 further includes here a lower portion 32 extending from the clamping portion 30 opposite the upper portion 28.
[0078] The upper portion 28, the clamping portion 30 and, here in addition, the lower portion 32, each correspond to a section of the inner surface 20 along the axial direction.
[0079] The upper portion of 28 includes a step 34.
[0080] The step 34 comprises an axial segment 36 and a segment with a radial component 38.
[0081] The axial segment 36 extends from the drinking hole 24 over a length.
[0082] The axial segment 36 extends along the axial direction.
[0083] The axial segment 36 is here a cylinder with a circular base centered around the axis principal X.
[0084] The axial segment 36 has a height h measured along the axial direction.
[0085] The height h is, for example, greater than or equal to 0.3 mm, preferably greater than or equal to 0.5 mm, preferably greater than or equal to 0.7 mm.
[0086] The height h is, for example, between 0.4 mm and 2 mm.
[0087] In the illustrated embodiment example, the height h is close to 0.7 mm.
[0088] The height h is equal to the extension length of the axial segment 36.
[0089] The thickness e of the neck 16 is measured between the clamping portion 30 of the inner surface 20 and the outer surface 22. It is, for example, between 0.5 mm and 2 mm.
[0090] In the illustrated embodiment, the thickness e of the neck is equal to 1.7 mm.
[0091] The ratio of the height h of the axial segment 36 to the thickness e of the neck 16 is in particular between 1 / 4 and 1 / 2.
[0092] In the illustrated embodiment, the ratio height h of the axial segment 36 to the thickness e of the neck 16 is approximately 0.41.
[0093] The radial component segment 38 connects the axial segment 36 to the clamping portion 30.
[0094] The radial component segment 38 has a non-zero dimension n along the radial direction.
[0095] The diameter of the radial component segment 38 of the inner surface 20 decreases, here continuously, more particularly strictly, from the axial segment 36 towards the clamping portion 30.
[0096] The radial component segment 38 has a radial dimension n, that is to say measured along the radial direction.
[0097] The radial dimension n is, for example, greater than or equal to 0.1 mm, preferably greater than or equal to 0.15 mm, preferably greater than or equal to 0.2 mm.
[0098] In the illustrated embodiment example, the radial dimension n is close to 0.225 mm.
[0099] The ratio of the radial dimension n of the segment with radial component 38 to the thickness e of the neck 16 is in particular between 1 / 20 and 1 / 5.
[0100] In the illustrated embodiment example, the ratio of radial dimension n of the segment with radial component 38 to the thickness e of the neck 16 is approximately 0.13.
[0101] The ratio of the height h of the axial segment 36 to the radial dimension n of the segment with radial component 38 is, for example, greater than or equal to 2, preferably greater than or equal to 3.
[0102] In one embodiment, the radial component segment 38 is, for example, a radial segment. The radial segment then corresponds to a ring perpendicular to the principal axis X.
[0103] Alternatively, the radial component segment 38 comprises a radial component and an axial component, for example as in the example shown.
[0104] The axial segment 36 is, for example, connected to the rim 24 and / or to the radial component segment 38 via a chamfer or a fillet.
[0105] This is particularly advantageous for centering the sealing skirt, described below, during assembly of the assembly.
[0106] The radial component segment 38 is connected to the axial segment 36 and / or to the clamping portion 30 via a chamfer or a fillet.
[0107] This is particularly advantageous in terms of the progressive tensioning of the sealing skirt described below during the assembly of the whole.
[0108] The clamping portion 30 includes an axial portion, extending along the axial direction.
[0109] The axial portion has a circular cylindrical shape around the main axis X.
[0110] The axial portion is here the part of the clamping portion 30 closest to the upper portion 28.
[0111] The drinking hole 24 comprises a radial portion 40.
[0112] The radial portion 40 extends in a plane perpendicular to the principal axis X.
[0113] The radial portion 40 here forms a ring perpendicular to the principal axis X.
[0114] The radial portion 40 has a radial dimension, that is to say, measured along the radial direction, greater than or equal to 0.4 mm, in particular greater than or equal to 0.6 mm, in particular greater than or equal to 0.8 mm, and in particular greater than or equal to 1 mm.
[0115] The radial portion 40 forms a free end of the neck 16, more particularly of the container 12, along the axial direction.
[0116] The closing member 14 is adapted to cooperate with the neck 16 to seal the container 12, more particularly the opening 18, in a tight closure configuration.
[0117] A principal axis and an axial direction are defined relative to the closing member 14, corresponding to the principal axis and axial direction defined previously with regard to the container 12, when the closing member 14 cooperates with the neck 16.
[0118] In a particular embodiment, the closure member 14 is, for example, made of the same copolyester material as the container 12, and more particularly of polyethylene terephthalate (PET).
[0119] The closing member 14 includes a sealing plate 42, a fixing skirt 44 and a sealing skirt 46.
[0120] The obturator plate 42 is adapted to extend transversely to the opening 18 of the neck 16 when the closing member 14 cooperates with the neck 16.
[0121] The sealing plate 42 has a lower surface 48 designed to extend opposite the container 12.
[0122] The lower surface 48 has a stop circumference 50.
[0123] The stop circumference 50 extends in a plane perpendicular to the principal axis X.
[0124] The sealing skirt 46 extends inside the fixing skirt 44 in a radial direction defined with respect to the main axis X.
[0125] The stop circumference 50 extends radially between the fixing skirt 44 and the sealing skirt 46.
[0126] The fixing skirt 44 extends from the obturator plate 42, more particularly from the lower surface 48.
[0127] The fixing skirt 44 extends from an outer perimeter of the shutter plate 42.
[0128] The fixing skirt 44 extends here from the obturator plate 42 in the axial direction.
[0129] The fixing skirt 44 has a general circular cylindrical shape.
[0130] The fixing skirt 44 comprises an inner surface 52 and an outer surface 54.
[0131] The inner surface 52 is designed to extend in relation to the outer surface 22 of the neck 16 when the closing member 14 cooperates with the neck 16.
[0132] The fixing skirt 44, more particularly the inner surface 52, carries complementary fixing elements 56, the complementary elements 56 being complementary to the fixing elements 26 of the neck 16 so as to secure the closing member 14 to the neck 16 of the container 12 by cooperation of the fixing elements 26 and the complementary elements 54.
[0133] The complementary elements 56 include, for example, a tapping or portions of tapping, complementary to the thread.
[0134] The sealing skirt 46 extends perpendicularly to the sealing plate 42.
[0135] The sealing skirt 46 extends from the obturator plate 42, more particularly from the lower surface 48.
[0136] The sealing skirt 46 extends from a circumference of the sealing plate 42.
[0137] The sealing skirt 46 extends here from the shutter plate 42 according to the axial direction.
[0138] The sealing skirt 46 has a generally circular cylindrical shape. By essentially cylindrical, it is meant here that the sealing skirt 46 may have a slight draft with respect to the main axis, for example on the order of 0.5° to 3° of angle.
[0139] The sealing skirt 46 comprises an inner surface 58 and an outer surface 60.
[0140] The outer surface 60 is designed to extend in relation to the inner surface 20 of the neck 16 when the closing member 14 cooperates with the neck 16.
[0141] The inner surface 58 extends, for example, along the axial direction.
[0142] The outer surface 60 has an axial portion 62.
[0143] The outer surface 60 also has a free portion 64.
[0144] The axial portion 62 extends along the axial direction.
[0145] The axial portion 62 of the outer surface 60 is here substantially a cylinder circular around the main axis. Again here, by substantially cylindrical, we mean that the axial portion 62 may have a slight chamfer with respect to the main axis, for example of the order of 0.5° to 3° of angle.
[0146] The axial portion 62 is provided to extend radially in relation to the upper portion 28 and the clamping portion 30 of the inner surface 20 of the neck 16 when the closing member 14 cooperates with the neck 16 in the sealing configuration.
[0147] The free portion 64 extends from the axial portion 62 opposite the obturator plate 42.
[0148] The diameter of the outer surface 60 of the free portion 64 decreases continuously from the axial portion 62 to a free end of the sealing skirt.
[0149] The closure element is adapted to be mounted removably on the container, at the neck, so as to close the opening 18.
[0150] The closing member 14 is thus movable relative to the container 12 between a position in which it does not cooperate with the container and a position corresponding to the leak-proof closure configuration.
[0151] The fixing elements 26 cooperate with the complementary elements 56 to guide the movement of the closing member relative to the container, for example a screwing movement, here up to the tight closing configuration.
[0152] During the cooperation of the closing member 14 with the collar 16, the sealing skirt 46, the collar 16 and the fixing skirt 44 are arranged in this order according to the radial direction, the sealing skirt 46 being closest to the main axis X.
[0153] During the cooperation of the closing member 14 with the collar 16, the collar 16 is radially between the sealing skirt 46 and the fixing skirt 44.
[0154] The radial portion 40 can form an axial stop contact with the closing member 14 when the closing member 14 cooperates with the neck 16 in a sealed closing configuration.
[0155] More specifically, the radial portion 40 can abut against the lower surface 48, here more particularly the abutment circumference 50, in the watertight closure configuration. The abutment circumference 50 also includes here an annular relief 51 entering into axial interference contact with the radial portion 40, in the watertight closure configuration.
[0156] The sealing skirt 46, more particularly the axial portion 62, is configured to be in tight contact with the inner surface 20 of the neck 16, more particularly with the axial portion included in the clamping portion 30 of the inner surface of the neck, when the closure member 14 cooperates with the neck 16, more particularly in the tight closure configuration.
[0157] The term "tightening contact" means that a radial force is applied between the closing member and the neck at that level.
[0158] Here, the inner surface of the neck has, in the axial portion of the clamping portion 30, a diameter that is smaller, preferably strictly smaller, than the outer diameter of the sealing skirt adapted to cooperate with the clamping portion 30 when the closing member 14 cooperates with the neck 16, more particularly in the tight closing configuration, of a so-called radial interference distance ir.
[0159] Here, said outer diameter corresponds to the diameter of the axial portion 62.
[0160] The radial interference is preferably greater than or equal to 0.05 mm, preferably greater than or equal to 0.1 mm, preferably greater than or equal to 0.15 mm, preferably greater than or equal to 0.2 mm.
[0161] This provides a tight contact at a distance from the rim, so as to limit the forces applied to the rim, to limit the risk of stress cracking.
[0162] The ratio of radial interference ir to height h of axial segment 36 is less than or equal to 0.33, preferably less than or equal to 0.25, preferably less than or equal to 0.2.
[0163] The assembly is arranged such that, in the sealed closure configuration, there is no clamping contact between the included rim 24 and the excluded clamping portion 30.
[0164] In use, a user can separate the container and the closure element, so as to release the opening 18, for example to pour the cosmetic product or to refill the container.
[0165] Then, it can close the container 12 with the sealing member 14, more specifically by cooperation of the fastening elements and the complementary fastening elements, here for example by a screwing movement. The user moves the sealing member 14 relative to the container 12 until the leak-proof closure configuration is reached, that is to say here until it comes to rest at the radial portion 40.
[0166] Alternatively, the sealing member 14 is formed by a service capsule, classically comprising a base having the fixing skirt 44, the sealing skirt 46 and the sealing plate 42, the latter being provided with a distribution orifice selectively closed by a pin extending from the lower face of a cover hinged relative to the base.
[0167] When the obturator 14 cooperates with the neck 16, the clamping contact is at the level of the clamping zone 30, at a distance from the rim 24 in the axial direction.
[0168] The axial segment 36 allows the rim clamping zone to be axially offset without any additional radial offset compared to the radially oriented segment. This results in a step with a particularly large axial offset, including relative to the radial offset, specifically designed to compensate for the radial interface. This allows for a relatively thick rim at the edge, especially compared to a chamfer or fillet where the axial offset is equal to the radial offset, as thinning the rim weakens the area around it. Thus, this helps prevent rim cracking.
[0169] In addition, when the obturator is put in place, for example by screwing, the radial surface of the rim forms a stop, so that if the size of the contact surface is reduced, this applies a greater pressure, which is also likely to weaken the area around the rim.
[0170] Furthermore, numerical simulations have shown that the stresses are better distributed, more uniform along the circumferential direction in the area near the rim, with a step according to the invention, compared to a fillet or a chamfer which would have an axial offset similar to the step.
[0171] A manufacturing process for the assembly will now be described with reference to the example described above.
[0172] The process comprises the following steps: - Creation of a preform, - Blow molding, possibly with stretching, of the preform to obtain the container, and - Production of the closing mechanism, in particular by injection molding.
[0173] The preform is, for example, produced by injection molding.
[0174] The preform has a neck with the same geometry as the neck of the container to be produced, as described previously.
[0175] During the blow molding step, the preform is placed in a blow mold having a molding cavity corresponding to the external shape of the container.
[0176] The preform is heated to bring it to the proper temperature before blowing, and possibly stretch-blowing.
[0177] Then, air is injected into the preform, through the opening delimited by the neck and the preform is possibly simultaneously stretched in the case of a stretch-blowing manufacturing process.
[0178] The preform is thus blown, so as to obtain the container.
[0179] The neck opening is in the area of the last injected preform, into which Problems with venting or evacuating air from the mold can arise, as well as the risk of suboptimal temperatures, hindering optimal filling of the mold cavity. The neck opening is therefore susceptible to being more fragile, and therefore more susceptible to stress cracking. This particularly underscores the importance of the assembly according to the invention for such a manufacturing process.
[0180] Furthermore, the thinner the rim, the more susceptible it is to venting defects and suboptimal filling of the mold cavity, and therefore to the formation of injection defects, such as microbubbles, which can promote stress cracking. Thus, the assembly according to the invention makes it possible, on the one hand, to limit the formation of injection defects, and, on the other hand, subsequently to limit the impact of stresses at the rim that could lead to cracking.
Claims
1. Demands Set (10) of cosmetic product packaging, comprising: - a container (12) having a principal axis (X) defining an axial direction, the container (12) having a neck (16) defining an opening (18), the neck (16) comprising: an inner surface (20), an outer surface (22) bearing fastening elements (26), and a drinking spout (24) connecting the inner surface (20) and the outer surface (22); - a closing element (14) adapted to cooperate with the neck (16) to seal the container (12) and comprising: a sealing plate (42) adapted to extend transversely across the opening (18) of the container (12), a fixing skirt (44) carrying additional elements (56) of fastening, the complementary elements (56) being complementary to the fastening elements (26) of the neck (16) so as to secure the closure member (14) to the neck (16) of the container (14), and a sealing skirt (46), the sealing skirt (46) extending inside the fixing skirt (44) in a radial direction, the sealing skirt (46) extending perpendicularly to the sealing plate (42), characterized in that the inner surface (20) of the neck (16) comprises an upper portion (28) extending from the rim (24) and a clamping portion (30) extending from the upper portion (28) and away from the rim (24) in the axial direction, in that the upper portion (28) of the inner surface (20) of the neck (16) includes a notch (34), the notch (34) comprising an axial segment (36) extending from the rim (24) over a length and a segment with a radial component (38) connecting the axial segment (36) to the clamping portion (30) of the inner surface (20) of the neck (16), and in that the sealing skirt (46) of the closing member (14) is configured to be in tight contact with the inner surface (20) of the neck (16) in an axial portion included in the portion of clamping (30) of the inner surface (20) of the neck (16), when the closing member (14) cooperates with the neck (16).
2. Assembly according to claim 1, wherein the axial segment (36) is connected to the rim (24) and / or to the radial component segment (38) via a chamfer or fillet, and / or the radial component segment (38) is connected to the clamping portion (30) of the inner surface (20) of the neck (16) via a chamfer or fillet.
3. Assembly according to claim 1 or 2, wherein the container (12) is made of copolyester material, in particular a semi-aromatic copolyester, such as polyethylene terephthalate (PET), and the closure member (14) is, in particular, made of the same copolyester material, and more particularly of polyethylene terephthalate (PET).
4. Assembly according to any one of claims 1 to 3, wherein the axial segment (36) of the step (34) has a height (h) measured along the axial direction greater than or equal to 0.3 mm, preferably greater than or equal to 0.5 mm, preferably greater than or equal to 0.7 mm, for example between 0.4 mm and 2 mm.
5. Assembly according to any one of claims 1 to 4, wherein the axial segment (36) of the step (34) has a height (h) measured along the axial direction, and the neck (16) has a thickness (e) measured between the clamping portion (30) of the inner surface (20) and the outer surface (22), and wherein the ratio of the height (h) to the thickness (e) is between 1 / 4 and 1 / 2.
6. Assembly according to any one of claims 1 to 5, wherein the radial component segment (38) has a radial dimension (n) greater than or equal to 0.1 mm, preferably greater than or equal to 0.15 mm, preferably greater than or equal to 0.2 mm.
7. Assembly according to any one of claims 1 to 6, wherein the radial component segment (38) has a radial dimension (n), and the neck (16) has a thickness (e) measured between the clamping portion (30) of the inner surface (20) and the outer surface (22), and wherein the ratio of the radial dimension (n) to the thickness (e) is between 1 / 20 and 1 / 5.
8. Assembly according to any one of claims 1 to 7, wherein the drinking spout (24) comprises a radial portion (40), the portion radial (40) forming a free end of the neck (16), the radial portion (40) having a radial dimension greater than or equal to 0.4 mm, in particular greater than or equal to 0.6 mm, in particular greater than or equal to 0.8 mm, and in particular greater than or equal to 1 mm.
9. Assembly according to any one of claims 1 to 8, wherein the axial segment (36) of the step (34) has a height (h) measured along the axial direction, the radial component segment (38) having a radial dimension (n), the ratio of the height (h) of the axial segment (36) to the radial dimension (n) of the radial component segment (38) being greater than or equal to 2, preferably greater than or equal to 3.
10. Assembly according to any one of claims 1 to 9, wherein the inner surface (20) of the neck (16) has, in the axial portion of the clamping portion (30), a diameter less than, preferably strictly less than, the outer diameter of the sealing skirt (46) adapted to cooperate with the clamping portion (30) when the closing member (14) cooperates with the neck (16) by a distance called radial interference (ir), the radial interference (ir) being preferably greater than or equal to 0.05 mm, preferably greater than or equal to 0.1 mm, preferably greater than or equal to 0.15 mm, preferably greater than or equal to 0.2 mm.
11. Assembly according to claim 10, wherein the axial segment (36) of the step (34) has a height (h) measured along the axial direction, the ratio of the radial interference (ir) to the height (h) of the axial segment (36) being less than or equal to 0.33, preferably less than or equal to 0.25, preferably less than or equal to 0.2.