ES2640117T3 - Enhanced tube that exploits the properties of the skirt for the tube head - Google Patents

Abstract

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 internal face (11) and an external face (13), said tube head (1) also comprising an insert (21) arranged in contact with said face internal (11), so that it forms a barrier between the body (5) and the product contained in the internal volume (V), the said external face (13) of the shoulder (7), in front of the insert, comprising a surface of fixing (23) to said skirt (3), characterized in that said fixing surface (23) has a radius of curvature between 2.5 mm and 5 mm.

Description

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DESCRIPTION

Enhanced tube that exploits the properties of the tube head skirt

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

The flexible tubes are usually constituted by a tube head associated with a skirt, the tube head comprising a neck for the extraction of a product contained in the tube, while the skirt forms the internal volume of the tube adapted to receive a product.

The skirt is traditionally formed by a multilayer sheet, adapted to present satisfactory mechanical resistance and sealing properties.

The tube head is usually made by injection of plastic material, and comprises an insert that conforms to the inner side of the shoulder of the tube head, so that it forms a barrier that separates the tube head itself from the product contained in the tube and thus protect them, in particular in the case of products that have a very aggressive composition with respect to the material from which the tube head is formed and / or products very sensitive to oxidation under the effect of air oxygen.

In general, the skirt is attached to the outer side of the shoulder, while the insert is attached to the inner side of the shoulder. There is therefore a zone of weakness between the insert and the skirt, at which level the tightness of the tube is only secured by the material that forms the tube head. In order to best protect the tube head and limit sealing problems, it is known to partially cover the outer face of the shoulder by the skirt so as to benefit from the properties of the multilayer sheet that makes up the skirt. Classically, the shape of the shoulder consists primarily of a cylindrical portion, then a conical trunk portion whose diameter decreases in the direction of the neck. The skirt then covers the cylindrical portion, and then at least a part of the conical trunk portion of the shoulder. The length of the coating is limited however by the appearance of deformations of the limb of the skirt, especially folds that prevent a good fixation of the skirt to the head, a good tightness and a good protection of the tube head and the contained product. These folds appear above all in the passage of the junction zone between the cylindrical portion and the truncated cone portion, which sometimes has a living 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 tube head material.

A tube head according to the preamble of claim 1 is known from WO 2014/032878.

There is therefore a need for a tube in which the coating length of the tube head increases thus improving the tightness of the tube head.

For this purpose, the present invention proposes a tube head adapted to be associated with a skirt so that they form an internal volume of the tube, said tube head comprising a body, said body comprising a neck and a shoulder comprising a inner face and an outer face, said tube head comprising also an insert arranged in contact with said inner face, so as to form a barrier between the body and the product contained in the inner volume, said outer shoulder face comprising , in front of the insert, a fixing surface to said skirt, said fixing surface having a radius of curvature between 2.5 mm and 5 mm.

By "opposite", it is understood that the fixing 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 fixing surface of a skirt, the appearance of cracks, especially folds, is thus limited when the tip of the skirt is folded so that it partially covers the outer face of the shoulder. It is then possible to benefit from the properties of the multilayer sheet that composes the skirt over a more important length without seeing deformations that prevent a good fixation of the skirt to the head. Thus, by the proper application of the skirt in the area where it must be in front of the insert, a satisfactory protection of the tube head and the product contained in the tube is ensured.

According to different embodiments of the invention, which may be taken jointly or separately:

- the aforementioned radius of curvature is between 2.8 mm and 5 mm,

- the said fixing surface represents at least 1/3 of the external face of the shoulder,

- each fixing surface represents at least 1/2, or at least 2/3 of the outer face of the shoulder,

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- the said body is made of a material chosen from among 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 also comprises an iron-based oxygen absorber, based on sulphite, vitamins, or additive polyamides.

The invention also concerns a flexible tube for liquid or paste consistency product. The said tube comprises.

- a tube head as described above,

- a skirt that has a proximal limb attached to the fixing surface so that it partially covers the outer face of the shoulder.

According to different features of the invention that may be taken jointly or separately:

- the aforementioned proximal limb of the skirt has a radius of curvature between 2.5 mm and 5 mm,

- the radius of curvature is preferably between 2.8 mm and 5 mm,

- said proximal extremity is arranged in front of an outer periphery of the insert, so that said proximal extremity covers at least 1/5 of an outer portion of the insert,

- the said proximal limb covers at least 1/4 or 1/3, or 1/2 of the outer portion of the insert,

- said proximal limb and said outer periphery of the insert define a channel of shoulder material between the insert and the skirt, said channel of thickness E and length L,

- the length L of the channel is greater than 0.5 mm, or greater than 1 mm,

- the mentioned length L of the channel is between 0.5 mm and 5 mm, or between 1 mm 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 mm and 0.6 mm, or between 0.4 mm and 0.55 mm.

Other features, objectives and advantages of the invention will be apparent from the description that follows, which is purely illustrative and not limiting, and which must be read in relation to the accompanying drawings, in which:

- Figure 1 is a schematic view of a tube head according to an aspect of the invention,

- Figure 2 is a partial schematic view of a tube according to an aspect of the invention,

- Figure 3 is a detailed view of a portion of Figure 2.

In the set of figures, the common elements are indicated by identical numerical references.

Figure 1 shows a sectional view of a tube head 1 according to an aspect of the invention. Said tube head 1 is adapted to be associated with a skirt 3 so that they form an internal volume V of the tube (partially visible in Figure 2). The tube head 1 comprises a body 5 comprising a shoulder 7 and a neck 9 attached to the shoulder 7. Said shoulder 7 extends substantially radially from the neck 9 defining a longitudinal axis Z-Z. It comprises an internal face 11 oriented towards the internal volume V of the tube defined by the skirt 3 and an external face 13 oriented opposite to this internal volume V.

The neck 9 defines an internal conduit 15, which is used for the distribution of a product contained in the internal volume V of the tube. In the embodiment shown, the neck 9 comprises a threaded 17 on its outer periphery, adapted to allow a screw to be screwed onto the neck 9 comprising a complementary thread, as well as a support surface 19 that can perform a stop function for said plug.

The tube head 1 also comprises an insert 21 arranged 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 shown is solid and comprises a central portion 22 that forms an operculum adapted to seal the neck 9 prior to its first use during which said central portion 22 is at least partially perforated. Other embodiments may comprise an insert that has a central hole that typically corresponds to the internal diameter of the neck 9, and thus does not need to cut the insert prior to the first use of the tube.

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As shown in Figure 2, the shoulder 7 is attached to the skirt 3 that forms the associated flexible tube body and thus defines an internal volume V of the tube that can contain a product of liquid or pasty consistency.

The said outer face 13 of the shoulder 7 thus comprises a fixing surface 23 to which a proximal end 25 of the said skirt 3 is attached so that it partially covers the outer face 13 of the shoulder 7. In other words, the fixing surface 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 head of the tube 1 and the skirt 3 are assembled. In this embodiment, said fixing surface 23 is located on 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 limb next 25 of the skirt 3 so that the union between the skirt 3 and the shoulder 7 is made without material thickness. More generally, said general fixing surface is formed by a rounded part of the shoulder 7, located in front of the insert 21.

The tube head 1 is attached to the skirt 3, typically by overmolding the tube head 1 onto the skirt 3. In other words, the skirt 3, previously formed, is placed inside a mold into which it is then injected the material of the tube head 1 to form said tube head 1.

In variant, the tube head 1 is attached to the skirt 3 by welding or glued by assembling the proximal end 25 of the skirt 3 to the fixing surface 23 of the shoulder 7 of the tube head 1 previously formed, especially by injection or by compression injection , or by any other techniques.

According to the invention, the fixing surface 23 has a radius of curvature comprised between 2.5 mm and 5 mm, preferably between 2.8 mm 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 classic tube head without deformations of the tip 25 of the skirt 3, especially folds. Advantageously, said fixing surface 23 represents at least 1/3 of the outer face 13 of the shoulder 7, or at least 1/2, or at least 2/3 of the outer face 13 of the shoulder 7, measured at the foot of the neck, in this case of the stop 19 on the outer periphery of the head 1.

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

Figure 3 presents a detailed view of a portion of Figure 2, indicated in Figure 2 by an area surrounded by a circle.

Figure 3 allows visualizing the proximal extremity 25 of the skirt 3 that partially covers the external face 13 of the shoulder 7. It is arranged in front of an external periphery 27 of the insert 21, so that said proximal extremity 25 covers at least 1 / 5 of an outer portion 31 of the insert 21, or at least 1/4, or 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 in Figure 2. The skirt 3 is thus superimposed according to the direction defined by the ZZ axis with the outer periphery 27 of the insert 21, so that, in a portion of the tube head 1 according to ZZ, the tube 1 comprises outside the inside of the tube, the skirt 3, the shoulder 7 and then the insert 21.

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

A thickness E of this channel 29 is defined, corresponding to the average thickness of material that forms the shoulder 7 between the insert 21 and the skirt 3. The said thickness E is measured so that the shortest distance between a point of the upper face of the insert 21 and the lower face of the proximal extremity 25 of the skirt 3 or also the shortest distance between a point of the lower face of the proximal extremity 25 of the skirt 3 and the upper face of the insert 21.

A length L of the channel 29 is also defined, corresponding to the distance between the proximal extremity 25 of the skirt 3 and the outer flange of the insert 21. This distance is measured between the proximal extremity 25 of the skirt 3 and the orthogonal projection of the external flange of the insert 21 on the proximal end 25 of the skirt 3, with respect to an axis tangent to said insert at the level of said external flange.

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

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

The channel 29 between the skirt 3 and the insert 21 allows 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, in a tube head body 5 1 made of an advantageous material, such as the materials that will be presented below.

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

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

Claims (9)

5 10 fifteen twenty 25 30 1. Tube head (1) adapted to be associated with a skirt (3) so that they form an internal volume (V) of the tube, said tube head (1) comprising a body (5), said body comprising (5) a neck (9) and a shoulder (7) comprising an inner face (11) and an outer face (13), said tube head (1) also comprising an insert (21) arranged in contact with the said inner face (11), so as to form a barrier between the body (5) and the product contained in the inner volume (V), said outer face (13) comprising the shoulder (7), facing the insert, a fixing surface (23) to said skirt (3), characterized in that said fixing surface (23) has a radius of curvature between 2.5 mm and 5 mm. 2. Tube head (1) according to the preceding claim, wherein said fixing surface (23) represents at least 1/3 of the outer face (13) of the shoulder (7). 3. 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, ethylene copolymer and of vinyl alcohol, or a mixture of these materials. 4. Tube head (1) according to the preceding claim, in which the material in which said body is made (5) also comprises an iron-based oxygen absorber, based on Sulphite, vitamins, or additive polyamides. 5. Flexible tube for liquid or paste consistency product, comprising: - a tube head (1) according to one of claims 1 to 4, - a skirt (3) having a proximal limb (25) attached to the fixing surface (23) so that it partially covers the outer face (13) of the shoulder (7). 6. Tube according to the preceding claim, wherein said proximal end (25) is arranged in front of 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). 7. 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 shoulder material (7) between the insert ( 21) and the skirt (3), said channel (29) being of thickness E and length L. 8. Tube according to the preceding claim, in which the length L of the channel (29) is greater than 0.5 mm. 9. Tube according to any one of claims 7 or 8, wherein the thickness E of the channel (29) is greater than 0.2 mm.