EP2921418A1 - Improved tube using the properties of the skirt for the tube head - Google Patents

Abstract

The present invention relates to a tube head (1) adapted to be associated with a skirt (3) so as to form an internal volume (V) of the tube, said tube head (1) comprising a body (5), said body (5) comprising a neck (9) and a shoulder (7) comprising an inner face (11) and an outer face (13), said tube head (1) further comprising an insert (21) disposed in contact with said inner face (11), so as to form a barrier between the body (5) and the product contained in the internal volume (V), said outer face (13) of the shoulder (7) comprising, opposite the insert, an attachment surface (23) of said skirt (3), said attachment surface (23) having a radius of curvature greater than 2.5 mm. The invention also relates to a flexible tube for product with a liquid or pasty consistency, comprising such a tube head (1).

Description

The present invention relates to the field of flexible tubes for the storage and distribution of products with a liquid or pasty consistency, in particular cosmetic products.

Flexible tubes commonly consist of a tube head associated with a skirt, the tube head comprising a neck for extracting a product contained in the tube, while the skirt forms the internal volume of the tube adapted to receive a product.

The skirt is conventionally formed of a multilayer sheet, adapted to exhibit satisfactory mechanical strength and sealing properties.

The tube head is commonly made by injecting plastic material, and comprises an insert conforming to the inner face of the shoulder of the tube head, so as to form a barrier separating the tube head itself from the product. contained in the tube and thus protect them, particularly in the case of products having a very aggressive composition vis-à-vis the material of which is formed the tube head and / or products very sensitive to oxidation under the effect of the oxygen of the air.

In general, the skirt is linked to the outer face of the shoulder, while the insert is linked to the inner face of the shoulder. There is therefore a zone of weakness between the insert and the skirt, at which the sealing of the tube is provided solely by the material forming the tube head. To better protect the tube head and limit sealing problems, it is known to partially cover the outer face of the shoulder by the skirt to thus benefit from the properties of the multilayer sheet component skirt. Conventionally, the shape of the shoulder consists first of all in a cylindrical portion, then a frustoconical portion whose diameter decreases in the direction of the neck. The skirt then covers the cylindrical portion, then at least a portion of the frustoconical portion of the shoulder. The length of the covering is, however, limited by the appearance of deformations of the end of the skirt, in particular folds which prevent a good fixation of the skirt on the head, a good seal and a good protection of the tube head and the product contained. These folds appear especially at the passage of the junction zone between the cylindrical portion and the frustoconical portion, which sometimes has a sharp edge. In particular, in the case of tubes whose tube head is overmolded on the skirt, the material can be inserted into the folds during the injection of the material of the tube head.

There is therefore a need for a tube in which the lap length of the tube head is increased thereby improving the tightness of the tube head.
For this purpose, the present invention provides a tube head adapted to be associated with a skirt so as to form an internal volume of the tube, said tube head comprising a body, said body comprising a neck and a shoulder comprising an inner face and an outer face, said tube head further comprising an insert disposed in contact with said inner face, so as to form a barrier between the body and the product contained in the internal volume, said outer face of the shoulder comprising, opposite of the insert, an attachment surface of said skirt, said attachment surface having a radius of curvature greater than 2.5 mm.

By "facing" it is understood that the attachment surface is arranged so that once the skirt associated with the tube head, the skirt and the insert are superimposed.

By increasing the radius of curvature of the attachment surface of a skirt, it limits the appearance of cracks, especially creases, when the end of the skirt is folded so as to partially cover the outer face of the skirt. shoulder. It is then possible to benefit from the properties of the multilayer sheet constituting the skirt over a greater length without seeing deformations appear which prevent a good fixation of the skirt on the head. Thus, by the proper application of the skirt in the area where it must be facing the insert, satisfactory protection of the tube head and the product contained in the tube is ensured.

• ledit rayon de courbure est compris de préférence entre 2,8 et 5 mm,
• ladite surface d'attachement représente au moins 1/3 de la face externe de l'épaule,
• ladite surface d'attachement représente au moins 1/2, voire au moins 2/3 de la face externe de l'épaule,
• ledit corps est réalisé dans un matériau choisi parmi les suivants :
  • polyéthylène, polypropylène, polyéthylène téréphtalate, polyamide, copolymère d'éthylène et d'alcool vinylique, ou un mélange de ces matériaux,
• ledit matériau dans lequel est réalisé ledit corps comprend en outre un absorbeur d'oxygène à base Fer, à base Sulfite, des vitamines, ou des polyamides additivés.

According to various embodiments of the invention, which may be taken together or separately:

• said radius of curvature is preferably between 2.8 and 5 mm,
• said attachment surface is at least 1/3 of the outer face of the shoulder,
• said attachment surface is at least 1/2 or at least 2/3 of the outer face of the shoulder,
• said body is made of a material selected from the following:
  • polyethylene, polypropylene, polyethylene terephthalate, polyamide, copolymer of ethylene and vinyl alcohol, or a mixture of these materials,
• said material in which said body is made further comprises an iron-based oxygen absorber, based on sulfite, vitamins, or additive polyamides.

• une tête de tube telle que décrite précédemment,
• une jupe présentant une extrémité proximale liée à la surface d'attachement de manière à recouvrir partiellement la face externe de l'épaule.

The invention also relates to a flexible tube for product with a liquid or pasty consistency. Said tube comprises:

• a tube head as described above,
• a skirt having a proximal end attached to the attachment surface so as to partially cover the outer face of the shoulder.

• ladite extrémité proximale de la jupe a un rayon de courbure supérieur à 2,5 mm,
• ledit rayon de courbure est compris de préférence entre 2,8 et 5 mm,
• ladite extrémité proximale est disposée en vis-à-vis d'une périphérie externe de l'insert, de manière à ce que ladite extrémité proximale recouvre au moins 1/5 d'une portion externe de l'insert,
• ladite extrémité proximale recouvre au moins 1/4 voire 1/3, voire 1/2 de la portion externe de l'insert,
• ladite extrémité proximale et ladite périphérie externe de l'insert définissent un canal de matière de l'épaule entre l'insert et la jupe, ledit canal étant d'épaisseur E et de longueur L,
• la longueur L du canal est supérieure à 0.5 mm, voire supérieure à 1 mm,
• ladite longueur L du canal est comprise entre 0.5 et 5 mm, voire entre 1 et 2 mm,
• l'épaisseur E du canal est supérieure à 0,2 mm,
• l'épaisseur E du canal est comprise entre 0,2 et 0,6 mm, voire entre 0,4 et 0,55 mm.

According to different features of the invention that can be taken together or separately:

• said proximal end of the skirt has a radius of curvature greater than 2.5 mm,
• said radius of curvature is preferably between 2.8 and 5 mm,
• said proximal end is disposed opposite an outer periphery of the insert, so that said proximal end covers at least 1/5 of an outer portion of the insert,
• said proximal end covers at least 1/4 or even 1/3 or even 1/2 of the outer portion of the insert,
• said proximal end and said outer periphery of the insert define a channel of material of the shoulder between the insert and the skirt, said channel being of thickness E and length L,
• the length L of the channel is greater than 0.5 mm, or even greater than 1 mm,
• said length L of the channel is between 0.5 and 5 mm, or even between 1 and 2 mm,
• the thickness E of the channel is greater than 0.2 mm,
• the thickness E of the channel is between 0.2 and 0.6 mm, or even between 0.4 and 0.55 mm.

• la figure 1 est une vue schématique d'une tête de tube selon un aspect de l'invention,
• la figure 2 est une vue schématique partielle d'un tube selon un aspect de l'invention,
• la figure 3 est une vue détaillée d'une portion de la figure 2.

Other characteristics, objects and advantages of the invention will emerge from the description which follows, which is purely illustrative and nonlimiting, and which should be read with reference to the appended drawings, in which:

• the figure 1 is a schematic view of a tube head according to one aspect of the invention,
• the figure 2 is a partial schematic view of a tube according to one aspect of the invention,
• the figure 3 is a detailed view of a portion of the figure 2 .

In all the figures, the common elements are identified by identical reference numerals.

The figure 1 shows a sectional view of a tube head 1 according to one aspect of the invention. Said tube head 1 is adapted to be associated with a skirt 3 so as to form an internal volume V of the tube (partially visible figure 2 ). The tube head 1 comprises a body 5 comprising a shoulder 7 and a neck 9 connected to the shoulder 7. Said shoulder 7 extends substantially radially from the neck 9 which defines a longitudinal axis ZZ. It comprises an inner face 11 oriented towards the internal volume V of the tube defined by the skirt 3 and an outer face 13 facing away from this internal volume V.

The neck 9 defines an internal conduit 15 for dispensing a product contained in the internal volume V of the tube. In the embodiment shown, the neck 9 comprises a thread 17 on its outer periphery, adapted to allow screwing a cap on the neck 9 comprising a complementary thread, and a bearing surface 19 which can perform a stop function for such a plug.

The tube head 1 further comprises an insert 21 disposed in contact with said inner face 11 of the shoulder 7, so as to form a barrier between the body 5 and the product contained in the internal volume. The insert 21 as presented is solid and comprises a central portion 22 forming a lid adapted to close the neck 9 prior to its first use in which said central portion 22 is at least partially perforated. Other embodiments may comprise an insert having a central orifice typically corresponding to the internal diameter of the neck 9, and thus not requiring cutting of the insert prior to the first use of the tube.

As represented in the figure 2 , the shoulder 7 is linked to the skirt 3 forming the body of the associated flexible tube and thus defining the internal volume V of the tube which may contain a product with a liquid or pasty consistency.

Said outer face 13 of the shoulder 7 thus comprises an attachment surface 23 to which is connected a proximal end 25 of said skirt 3 so as to partially cover the outer face 13 of the shoulder 7. In other words, the surface of the shoulder Attachment 23 is the part of the outer face 13 of the shoulder 7 with which the proximal end 25 of the skirt 3 is in contact when the tube head 1 and the skirt 3 are assembled. In this embodiment, said attachment surface 23 is located at the outer periphery of the shoulder 7. It is formed here by a decrease in the thickness of the outer periphery of the shoulder 7. This decrease is substantially identical to the thickness of the proximal end 25 of the skirt 3 so that the connection between the skirt 3 and the shoulder 7 is made without extra material thickness. More generally, said general attachment surface is formed by a rounded portion of the shoulder 7, located opposite the insert 21.

The tube head 1 is connected to the skirt 3, typically by overmolding the tube head 1 on the skirt 3. In other words, the skirt 3, previously formed, is placed in a mold in which the material of the tube head 1 is then injected to form said tube head 1.

Alternatively, the tube head 1 is connected to the skirt 3 by welding or gluing by assembling the proximal end 25 of the skirt 3 to the attachment surface 23 of the shoulder 7 of the previously formed tube head 1, in particular by injection or compression injection, or by any other technique.

According to the invention, the attachment surface 23 has a radius of curvature greater than 2.5 mm, preferably between 2.8 and 5 mm. The proximal end 25 of the skirt 3 can thus partially cover the outer face 13 of the shoulder 7 over a length greater than a conventional tube head without any deformation of the end. 25 of the skirt 3, in particular folds do not appear. Advantageously, said attachment surface 23 represents at least 1/3 of the outer face 13 of the shoulder 7, or even at least 1/2, or even at least 2/3 of the outer face 13 of the shoulder 7, measured at the foot of the neck, here the stop 19 at the outer periphery of the head 1.

Once the tube head 1 and the assembled skirt 3, the attachment surface 23 of the shoulder 7 of the tube head and the proximal end 25 of the skirt 3 have a substantially identical radius of curvature. The radius of curvature of the proximal end 25 of the skirt 3 is thus greater than 2.5 mm, preferably between 2.8 and 5 mm.

The figure 3 presents a detailed view of a portion of the figure 2 , spotted on the figure 2 by an area surrounded by a circle.

The figure 3 allows to visualize the proximal end 25 of the skirt 3 which partially covers the outer face 13 of the shoulder 7. It is disposed vis-à-vis an outer periphery 27 of the insert 21, so that that said proximal end 25 covers at least 1/5 of an outer portion 31 of the insert 21, or even at least 1/4 or even 1/3 or 1/2 of the outer portion 31 of the insert 21. The outer portion 31 of the insert 21 extends substantially radially from the shoulder 7 as shown figure 2 . The skirt 3 is thus superposed in the direction defined by the axis ZZ with the outer periphery 27 of the insert 21, so that, on a portion of the tube head 1 along the axis ZZ, the tube 1 comprises from the outside to the inside of the tube, the skirt 3, the shoulder 7 and then the insert 21.

Said proximal end 25 and said outer periphery 27 of the insert 21 thus define a channel 29 of material of the shoulder 7 between the insert 21 and the skirt 3, corresponding to the material of the shoulder 7 between the proximal end 25 of the skirt 3 and the outer periphery 27 of the insert 21, these two elements being arranged on either side of the shoulder 7.

We define a thickness E of this channel 29, corresponding to the average thickness of the material forming the shoulder 7 between the insert 21 and the skirt 3. Said thickness E is measured so as to take the shortest distance between a point of the upper face of the insert 21 and the lower face of the proximal end 25 of the skirt 3 or even the shortest distance between a point of the lower face of the proximal end 25 of the skirt 3 and the upper face of the insert 21.

A length L of the channel 29 corresponding to the distance between the proximal end 25 of the skirt 3 and the external rim of the insert 21 is also defined. This distance is measured between the proximal end 25 of the skirt 3 and the orthogonal projection of the outer edge of the insert 21 on the proximal end 25 of the skirt 3 relative to an axis tangent to said insert at said outer edge.

The thickness E of the channel 29 is typically greater than 0.2 mm, preferably between 0.2 and 0.6 mm, or even between 0.4 and 0.55 mm.

The length L of the channel 29 is typically greater than 0.5 mm, or even greater than 1 mm. Preferably, it is between 0.5 and 5 mm, or even between 1 and 2 mm.

The channel 29 between the skirt 3 and the insert 21 makes it possible to satisfactorily limit the migration of oxygen between the outside and the inside of the tube, and thus prevent oxidation of a product contained in the tube, for a tube head body 1 made of an advantageous material such as the materials which will be presented hereinafter.

The body 5 is typically made of plastic. It may be made of several materials, among which may be mentioned polyolefins, barrier materials or mixtures of these materials. As examples of polyolefins, mention may be made of polyethylene, polypropylene, or a copolymer of these two materials. Examples of barrier materials are polyethylene terephthalate, polyamide, copolymers of ethylene and vinyl alcohol, or a mixture of these materials. It may further comprise an iron-based oxygen absorber based on sulphite, vitamins, or additive polyamides.

The skirt 3 and the insert 21 are typically formed of plastic and / or laminated metal; for example a multilayer assembly comprising one or more barrier layers limiting infiltration and leakage of components and one or more layers of plastic, such as polyethylene. The barrier layer may comprise a metal layer (of aluminum for example) and / or an ethylene-vinyl alcohol layer (EVOH).

Claims (10)

Tube head (1) adapted to be associated with a skirt (3) so as to form an internal volume (V) of the tube, said tube head (1) comprising a body (5), said body (5) comprising a neck (9) and a shoulder (7) comprising an inner face (11) and an outer face (13), said tube head (1) further comprising an insert (21) disposed in contact with said inner face (11) , so as to form a barrier between the body (5) and the product contained in the internal volume (V), said outer face (13) of the shoulder (7) comprising, facing the insert, a surface of attachment (23) of said skirt (3), said attachment surface (23) having a radius of curvature greater than 2.5 mm. Tube head (1) according to the preceding claim, wherein said attachment surface (23) is at least 1/3 of the outer face (13) of the shoulder (7). Tube head (1) according to any one of the preceding claims, wherein said body (5) is made of a material selected from the following: polyethylene, polypropylene, polyethylene terephthalate, polyamide, copolymer of ethylene and vinyl alcohol , or a mixture of these materials. Tube head (1) according to the preceding claim, wherein the material in which said body (5) is formed further comprises an oxygen-based oxygen absorber based on sulfite, vitamins, or additized polyamides. Flexible tube for liquid or paste-like product, comprising: - a tube head (1) according to one of claims 1 to 4, - a skirt (3) having a proximal end (25) connected to the attachment surface (23) so as to partially cover the outer face (13) of the shoulder (7). Tube according to the preceding claim, wherein said proximal end (25) of the skirt (3) has a radius of curvature greater than 2.5 mm. Tube according to any one of claims 5 or 6, wherein said proximal end (25) is disposed opposite an outer periphery (27) of the insert (21), so that said proximal end (25) covers at least 1/5 of an outer portion (31) of the insert (21). Tube according to the preceding claim, wherein said proximal end (25) and said outer periphery (27) of the insert (21) define a channel (29) of material of the shoulder (7) between the insert (21) and the skirt (3), said channel (29) being of thickness E and of length L. Tube according to the preceding claim, wherein the length L of the channel (29) is greater than 0.5 mm. Tube according to any one of claims 8 or 9, wherein the thickness E of the channel (29) is greater than 0.2 mm.

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