SINGLE-MATERIAL TUBE EQUIPPED WITH AN OVAL-SHAPED TUBE HEAD

Abstract

The invention relates to a flexible tube (100) for containing a liquid or paste-like product, comprising: - a tube head (1) including an upper wall (10) and an annular side wall (20), - a flexible skirt (60) fixed directly to the annular wall (20) of the head (1), the flexible skirt (60) comprising at least 50% by mass of high-density polyethylene; the tube (100) as a whole comprising at least 95% by mass of polyethylene; characterized in that the head (1) is made of polyethylene, the lower end edge (21) having an oblong shape; and in that the wall of the flexible skirt (60) has a thickness between 150 µm and 400 µm, and the head (1) is made of polyethylene (PE) or high-density polyethylene (HDPE). Figure for abbreviation: Figure 7

Description

Title of the invention: SINGLE-MATERIAL TUBE EQUIPPED WITH AN OVAL-SHAPED TUBE HEAD Technical field of the invention

[0001] The invention relates to a flexible tube intended to contain a liquid or paste-like product, comprising:

[0002] - a tube head comprising an upper wall and an annular side wall of which a lower end edge extends in a radial plane, said head comprising a distribution orifice,

[0003] - a flexible skirt fixed directly onto the annular wall of the head, the flexible skirt comprising at least 50% by mass of high-density polyethylene;

[0004] the tube comprising as a whole at least 95% polyethylene. Technical background

[0005] Flexible tubes comprising a tube head with a dispensing orifice, a cap mounted on the tube head that reversibly closes the dispensing orifice, and a flexible skirt attached to the tube head are known. A first aspect of the invention concerns the tube's ability to use as little plastic material as possible, particularly to reduce the tube's carbon footprint. Indeed, today, global plastic production represents one of the largest sources of packaging waste. The consumption and recycling of these plastic products is a major concern for national and regional organizations. Non-recycled plastic materials are currently disposed of through various processes, ranging from landfilling to energy recovery, including thermal and chemical treatments.To reduce plastic consumption, tubes have been proposed with a cap at the end to reversibly close the dispensing opening. Thus, the tube head and the cap become a single component, reducing the amount of plastic used to provide the same functionality. Furthermore, the invention also relates to a tube that can be easily recycled within the same recycling stream. Summary of the invention

[0006] The invention proposes a flexible tube intended to contain a liquid or paste-like product, comprising:

[0007] - a tube head comprising an upper wall and an annular side wall of which a lower end edge extends in a radial plane, said head comprising a distribution orifice,

[0008] - a flexible skirt fixed directly onto the annular wall of the head, the flexible skirt comprising at least 50% by mass of high-density polyethylene;

[0009] the tube comprising as a whole at least 95% polyethylene in pass;

[0010] characterized in that the head is made of polyethylene, in particular high-density polyethylene, the lower end edge having an oblong shape extending along a major axis in the plane and having two main vertices at each end of the major axis;

[0011] and in that the wall of the flexible skirt has a thickness between 150 pm and 400 pm, and the head is made of polyethylene or high-density polyethylene.

[0012] According to another feature of the tube made according to the teachings of the invention, the skirt is made of a multilayer material comprising an outer layer of polyethylene, an intermediate barrier layer of EVOH, and an inner layer of polyethylene.

[0013] According to another feature of the tube made according to the teachings of the invention, the flexible wall has a thickness between 250 pm and 350 pm.

[0014] According to another feature of the tube made according to the teachings of the invention, the distribution orifice is arranged in the center of the upper wall.

[0015] According to another feature of the tube made according to the teachings of the invention, said tube head comprising a hinged cover connected to the tube head by a hinge and movable between an open position and a closed position, said tube head, the hinged cover and the hinge being made of a single piece.

[0016] According to another feature of the tube made according to the teachings of the invention, the tube head is configured so that, when the cover is in the closed position, the head has a flat upper surface.

[0017] According to another feature of the tube made according to the teachings of the invention, the lid includes a tab to facilitate opening the lid by a user's finger.

[0018] According to another feature of the tube made according to the teachings of the invention, said tube head having a height hl between 5 and 20mm, in particular between 8 and 12mm.

[0019] According to another feature of the tube made according to the teachings of the invention, the length of the tube head along its major axis is between 15 and 75mm, in particular between 30 and 50mm.

[0020] According to another feature of the tube made according to the teachings of the invention, the d / hl ratio is between 2 and 6, in particular between 3 and 5.

[0021] According to another feature of the tube made according to the teachings of the invention, the protruding portion has a height h2 between 1.5 and 6mm, in particular between 2 and 4mm.

[0022] According to another feature of the tube made according to the teachings of the invention, the thickness of material at the level of the first upper wall and the second annular lateral wall is between 0.3 and 2mm, in particular between 0.5 and 1mm.

[0023] According to another feature of the tube made according to the teachings of the invention, the head includes an integrity indicator

[0024] According to another feature of the tube made according to the teachings of the invention, the integrity indicator comprises a self-adhesive tab which is glued straddling the lid and the side wall, the tab having a pre-cut forming a break initiation arranged along a joint plane between the lid and the side wall.

[0025] According to another feature of the tube made according to the teachings of the invention, the integrity indicator comprises an axially projecting tab made in one piece with a first associated element in the cover or the side wall, one free end of the tab being fixed to the other in the cover or the side wall, the tab having a break initiation arranged along a joint plane between the cover and the side wall.

[0026] According to another feature of the tube made according to the teachings of the invention, the skirt is obtained by extrusion.

[0027] According to another feature of the tube made according to the teachings of the invention, the skirt is obtained by welding two edges of a laminated sheet. Brief description of the figures

[0028] The invention will be better understood and other details, features and advantages of the invention will become apparent upon reading the following description, given by way of non-limiting example and with reference to the accompanying drawings in which:

[0029] - [Fig. 1] is a perspective view of a tube head made according to the invention in a closed configuration,

[0030] - [Fig. 2] is a perspective view of a tube head of [Fig. 1] in a open configuration, before the opening indicator tab is attached.

[0031] - [Fig. 3] is a perspective view showing the inside of a tube head of the [Fig. 1] in a closed configuration,

[0032] - [Fig. 4] is an axial sectional view along a sectional plane passing through the large axis of the tube head of [Fig. 1] in a closed configuration,

[0033] - [Fig. 5] is a larger-scale detail view of the distribution orifice such as represented in [Fig.4],

[0034] - [Fig. 6] is a perspective view of a tube made according to the teachings of the invention equipped with the tube head of [Fig.1],

[0035] - [Fig. 7] is a partial cross-sectional view of the tube of [Fig. 6] in which the skirt is shown in cross-section,

[0036] - [Fig.8] is a cross-sectional view of a wall of the tube in [Fig.6]. Detailed description of the invention

[0037] For the remainder of the description, elements having an identical structure or analogous functions will be designated by the same reference.

[0038] For the remainder of the description, an axial direction will be adopted which corresponds in the figures to that of the main axis "A" of the head 1. The axial direction is directed from the bottom, near the lower end, to the top, near the upper end.

[0039] For the remainder of this section, radial directions directed orthogonally to the axial direction, radiating from the principal axis, will also be adopted. Finally, tangential directions directed orthogonally to the axial and radial directions will be adopted.

[0040] As illustrated in Figures 1 to 6, the present invention relates to a head 1 for manufacturing a flexible tube 100 intended to contain a liquid or pasty product. The head 1 according to the invention comprises an upper wall 10. The upper wall 10 extends in a radial plane. An annular lateral wall 20 extends downwards from the periphery of the upper wall 10. A free lower end edge 21 of the lateral wall 20 extends in a plane "P". Said plane "P" is shown in [Fig. 1].

[0041] The head 1 has an oblong shape. More specifically, it is an oblong shape with two orthogonal radial axes of symmetry. A major axis "B" extends along the longest radial length of the head, while a minor axis "C" extends orthogonally to the major axis "B" along the shortest radial length of the head 1. The major axis "B" and the minor axis "C" are shown here in the radial plane "P". The intersections between the major axis "B" and the free lower edge 21 are called "principal vertices 211". Similarly, the intersections between the minor axis "C" and the free lower edge 21 are called "secondary vertices 212".

[0042] By way of non-limiting example, the oblong shape may be an oval shape or an elliptical shape.

[0043] At least the free lower end edge 21 of the lateral wall 20 has an oblong shape. The lateral wall 20 is flared here so that the free lower end edge 21 has dimensions greater than those of the upper wall 10.

[0044] The upper wall 10 has the aforementioned oblong shape as the lower end edge 21 but with reduced dimensions due to the flared shape of the lateral wall 20.

[0045] In an unrepresented variant of the invention, the upper wall 10 has a different shape from that of the lower edge 21, for example a circular shape.

[0046] The head 1 includes a distribution orifice 2. Advantageously, the distribution orifice 2 is located on the upper wall 10 of the head 1. The distribution orifice 2 is here arranged in the center of the upper wall 10, that is to say at the intersection between the major axis "B" and the minor axis "C".

[0047] The distribution orifice 2 is here extended axially downwards by a sleeve 200 which extends from the upper wall 10 to form a downward-opening well. One end of the sleeve 200 is located above the plane "P". The sleeve 200 extends, for example, to half of the lateral wall 20, as shown in [Fig. 4].

[0048] The head 1 also includes a projection 3 extending axially downward from an inner face belonging either to the upper wall 10 or to the lateral wall 20 to a free end. In the example shown in Figures 3 and 4, the projection 3 extends axially downward from an overhanging area of ​​the lateral wall 20. The projection 3 is arranged more specifically near one of the main vertices 211. Thus, the projection 3 is arranged at a radial distance from the distribution orifice 2.

[0049] As can be seen in particular in [Fig. 4], a free lower end portion 4 of said protrusion 3 projects axially downwards from said plane "P". In other words, if we consider that the tube head 1 defines an internal volume V by its upper wall 10 and its annular lateral wall 20, the protruding portion 4 of the protrusion 3 projects from said internal volume V.

[0050] In an alternative embodiment of the invention not shown, the distribution orifice is arranged eccentrically in the upper wall, near one of the main vertices. In this case, the protrusion can extend in line with the distribution orifice.

[0051] The projecting portion 4 here has a radial cross-section in the shape of a circular arc. The free-ended projecting portion 4 more specifically has the shape of a half-cylinder. This half-cylinder shape provides a sufficiently strong structure. In an alternative not shown, the projecting portion has a flat or circular cross-section.

[0052] The positioning means allows the tube head 1 to be oriented, in particular with respect to the decoration and / or a longitudinal weld 51 of the skirt during tube manufacturing, so that the skirt is subsequently fixed in a suitable position. Advantageously, the protruding portion 4 cooperates directly with the tooling of the tube production line and not with a component of the tube, as is the case in the prior art. For example, during the manufacture of a tube 100, the head 1 is produced by molding, then it is oriented by receiving the protruding portion 4 of the protrusion 3 in a slide while the head 1 is transported to an assembly area with a skirt of the tube 100.

[0053] Advantageously, the tube head 1 comprises a hinged cover 11. This cover 11 is connected to the tube head about a tangential axis by means of a hinge 12. It is movable between an open position, illustrated in [Fig. 2], and a closed position, illustrated in [Fig. 1]. The cover 11 has a flat upper face that extends in a radial plane in the closed position. The cover 11 has a contour identical in shape to that of the upper face 10. The cover 11 thus covers the upper face 10 in the closed position.

[0054] Alternatively, the cover 11 is smaller than the upper face 10. This further reduces the amount of plastic material required to manufacture the tube head 1. In this case, the upper face 10 has a recess the size of the cover to present a continuous flat surface when the cover 11 is closed.

[0055] Regardless of its embodiment, the cover 11 is designed to cover the distribution orifice 2 in its closed position.

[0056] The flat upper face of the cover 11 provides an appreciable aesthetic appearance and also allows the tube comprising the head 1 according to the invention to stand upright on its head.

[0057] Preferably, the entire tube head 1 according to the invention is formed from a continuous piece of material. The head 1 is thus made of a single piece, that is to say, a monolithic piece. In the prior art, a means for positioning a portion of the tube head cooperates with a complementary shape of another portion of the cap. Since the head 1 according to the invention is not divided into at least two separate pieces but is instead made of a single piece combining the functionalities of these two components, the method of centering the head 1 according to the invention relative to the skirt is a completely different approach.

[0058] Advantageously, the tube head 1, the hinged cover 11, and the hinge 12 are formed as a single piece. The entire tube head 1 assembly is advantageously formed by injection molding, in particular from plastic.

[0059] The head 1 is made of a plastic material, such as polyethylene. This is, for example, high-density polyethylene (HDPE) and / or recycled polyethylene (rPE).

[0060] Advantageously, the cover 11 includes a tab 13. This tab 13 facilitates gripping the cover 11 when it is opened by a user's finger. The presence of the tab 13 is particularly appreciated for a head with small dimensions and a low profile.

[0061] In an unshown variant of the invention, the annular side wall has a recess allowing a user to insert their finger in order to lift the cover. This variant can also be combined with the presence of tab 13 above said clearance depending on the geometry of the head.

[0062] The configuration of the head 1 according to the present invention allows the formation of a tube head 1 with reduced dimensions.

[0063] The tube head has a height hl, shown in particular in [Fig. 4]. The height hl is defined as the length of the line perpendicular to plane "P" measured between plane "P" and the outer face of the upper wall 10. Advantageously, the height hl of the tube head 1 is between 5 and 20 mm. Further advantageously, the height hl of the tube head 1 is between 8 and 12 mm. Even more advantageously, the height hl of the tube head 1 is between 9.3 and 10.3 mm.

[0064] The projecting portion 4 has a height h2, shown in particular in [Fig. 4]. Height h2 is defined as the length of the line perpendicular to plane "P" measured between plane "P" and the free end of the projecting portion 4. It is preferable that said projecting portion 4 have a height h2 in order to cooperate effectively with the tooling, in particular a slide, of the tube production line. Advantageously, the height h2 of the projecting portion 4 is between 1.5 and 6 mm. Advantageously still, the height h2 of the projecting portion 4 is between 2 and 4 mm. Advantageously still, the height h2 of the projecting portion 4 is between 2.5 and 3.5 mm. Such a height h2 of the projecting portion 4 allows for reliable positioning of the head 1 according to the invention.

[0065] Preferably, the hl / h2 ratio is between 1.5 and 5.5. Even more preferably, the hl / h2 ratio is between 2.5 and 4.5, in particular between 3 and 4.

[0066] The tube head 1 has a grip length d along its major axis "B", as shown in particular in [Fig. 4]. Advantageously, the length d of the head 1 is between 15 and 75 mm. Advantageously still, the length d of the head 1 is between 30 and 50 mm. Advantageously still, the length d of the head 1 is between 35 and 45 mm.

[0067] The design of the head 1 according to the present invention is characterized in particular by a substantially reduced height hl, especially compared to the length d of the head 1. This substantially flat design makes it possible to limit the amount of material required to manufacture the tube head 1, particularly plastic. Advantageously, the ratio d / hl is between 2 and 6. Even more advantageously, the ratio d / hl is between 3 and 5. A d / hl ratio such as the one described above characterizes the substantially flat design of the head 1 according to the present invention.

[0068] The head 1 according to the present invention has walls of significantly reduced thickness compared to prior art heads. This thin wall thickness makes it possible to limit the amount of material required to manufacture the tube head 1, particularly plastic. Advantageously, the material thickness at the wall The thickness of the material at the upper wall 10 and the annular side wall 20 is between 0.3 and 2 mm. Even more advantageously, the material thickness at the upper wall 10 and the annular side wall 20 is between 0.5 and 1 mm. Such a wall thickness significantly reduces the amount of material, particularly plastic, required to manufacture the tube head 1. Preferably, the material thickness at the hinge 12 is less than the material thickness at the upper wall 10 and the annular side wall 20.

[0069] Preferably, the hinged cover 11 includes a lug 110 for sealing the distribution orifice 2 when said cover 11 is in the closed position, as illustrated in Figures 4 and 5. The lug 110 has a cylindrical outer wall 111 intended to be inserted axially with a tight fit into the sleeve 200 of the orifice 2.

[0070] Usually, when the lid 11 has never been opened, the tight fit is sufficient to provide some resistance when the lid 11 is first opened. The resistance to opening is then reduced during subsequent openings due to the lubrication of the orifice 2 by the product contained in the tube. However, due to the low height of the head 1, there is a high risk that the product contained in the tube will seep between the lug 110 and the sleeve 200 before the first opening. To maintain good resistance to the first opening, the outer cylindrical face of the lug 110 has a lower bead 112A and an upper bead 112B arranged at a distance one above the other, as illustrated in [Fig. 5].Thus, the ridges 112A and 112B are dimensioned so that, when the cover 11 is closed, the lug 110 is in tight contact with the inner face of the sleeve 200 by two annular zones separated axially by a free space in which the lug 110 is not clamped against the sleeve 200. The presence of these two annular clamping zones with the sleeve 200 increases resistance to initial opening. Furthermore, the lower clamping zone acts as a first seal, preventing a large portion of the product contained in the tube from reaching the upper clamping zone. The upper clamping zone is therefore significantly less lubricated than the lower clamping zone. This ensures continued good resistance to initial opening.

[0071] Here, the lower bead 112A is in tight contact with the inner face of the sleeve 200 when the cover 11 is closed. It thus fulfills the function of the lower clamping zone. The upper bead 112B, on the other hand, is received with radial clearance in the sleeve 200, thus fulfilling the function of a free space. The upper clamping zone is formed by clamping the outer face of the lug 110 located above the second bead 112B against the inner face of the sleeve 200.

[0072] In an alternative embodiment of the invention, the beads 112A and 112B are both in tight contact with the inner face of the sleeve 200 when the cover 11 is closed. Thus, bead 112A serves as the lower clamping zone, while upper bead 112B serves as the upper clamping zone. The free space is defined by an area axially located between the two beads 112A and 112B.

[0073] According to another aspect of the invention, the head 1 includes an integrity indicator 5 which makes it possible to detect whether the cover 11 of the head 1 has already been opened once.

[0074] As shown in Figures 1 and 2, the integrity indicator 5 here comprises a tab 51 projecting axially downwards from the cover 11 to a free end. The tab 51 is formed as a single piece with the cover 11. When the cover 11 is closed, the tab 51 is received in a complementary recess 52 formed in the side wall 20. The free end of the tab 51 is fixed to the side wall 20, for example by welding, in particular by ultrasonic welding, as shown by line 53 of [Fig. 1]. The tab 51 has a break point 55 arranged along a joint plane 54 between the cover 11 and the side wall 20. The break initiation 55 is here formed by slots 56 made in the tongue 51 so that the free end of the tongue 51 is connected to the cover 11 only by bridges 57 of frangible material reserved between the slots.Thus, when an opening force is applied to the cover 11, the free end of the tab 51 remains fixed to the lateral wall 20 while the material bridges 57 are broken to allow the cover 11 to pivot towards its open position.

[0075] In addition, when the material bridges 57 break, there is a plastic deformation of the material which causes a change in the shape of the slots 56. This gives a visual indication to see if the lid 11 has already been opened once.

[0076] In an unrepresented variant of the invention, the integrity indicator comprises a self-adhesive tab which is glued straddling the lid and the side wall, the tab having a pre-cut forming a break point arranged along the joint plane between the lid and the side wall.

[0077] According to another aspect of the invention illustrated in particular in figures 7, 8 and 9, the present invention also relates to a tube 100 comprising a tube head 1 as described above and a flexible skirt 60.

[0078] Advantageously, the wall of the flexible skirt 60 is formed from a sheet of laminated material. Said sheet has two opposite edges and is rolled up on itself so that the opposite edges overlap. Said opposite edges are then welded together to form a longitudinal weld 61.

[0079] Advantageously, the longitudinal weld 61 of the skirt 60 of the tube 100 is positioned on the side of the hinge 12. Thus, as shown in [Fig. 7], when a The user is looking at tube 100 with tab 13 facing them. The longitudinal weld 61 is located on the side of the skirt 60, near a main vertex 211. This configuration is particularly advantageous with regard to the tube's aesthetic appearance. Indeed, the longitudinal weld 61 is an element of the skirt 60 considered unattractive, especially since this area of ​​the skirt 60 is often undecorated. It is therefore advantageous to position this longitudinal weld 61 near a sharply curved area, thus leaving space to decorate areas with a less pronounced curve, which are therefore more visible.

[0080] In an alternative to the invention not shown, the skirt 60 is obtained by extrusion. In this case, it does not have a weld. However, it remains necessary to correctly orient the head 1 with respect to the design of the skirt 60.

[0081] Preferably, the material forming the skirt 60 is a multilayer comprising at least one layer of plastic. Preferably, the laminate comprises at least one layer of HDPE (high-density polyethylene). Even more preferably, PE represents at least 50% by mass of the skirt 60 of the tube 100, in particular 70% by mass. Such a composition of the skirt 60 of the tube 100 further improves the recyclability of said tube 100, particularly in the same recycling stream as the head 1 made of PE.

[0082] The tube 100 as a whole preferably comprises at least 95% by mass of polyethylene (PE). It may be a mixture of polyethylenes of different densities (HDPE, LDPE, MDPE).

[0083] Advantageously, the laminated material forming the skirt 60 comprises at least one barrier layer. Advantageously still, the barrier layer is a plastic barrier layer of the EVOH (ethylene vinyl alcohol) type.

[0084] In the example shown in [Fig.8], the skirt 60 is made of a multilayer material comprising an outer layer 62 of PE, an intermediate barrier layer 63 of EVOH, and an inner layer 64 of PE.

[0085] Preferably, the wall of the skirt 60 has a thickness of between 150 µm and 400 µm. Preferably, the thickness is between 250 µm and 350 µm.

[0086] Preferably, the skirt 60 is fixed directly onto the tube head 1. More precisely, the upper end of the skirt 60 is fixed to a lower end section of the lateral wall 20. As a result, the skirt has an oval shape, at least in its upper section. No additional parts are required to fix the skirt 60 to the head 1. This reduces the number of parts and thus the amount of plastic material needed to manufacture the tube 100 according to the invention, thereby improving the recyclability of said tube 100.

[0087] Preferably, the skirt 60 is fixed to the tube head 1 by high-temperature welding or by overmolding.

Claims

Demands

1. Flexible tube (100) for containing a liquid or pasty product, comprising: - a tube head (1) including an upper wall (10) and an annular side wall (20) of which a lower end edge (21) extends in a radial plane (P), said head (1) including a dispensing orifice (2), - a flexible skirt (60) fixed directly to the annular wall (20) of the head (1), the flexible skirt (60) comprising at least 50% by mass of high-density polyethylene; the tube (100) as a whole comprising at least 95% by mass of polyethylene; characterized in that the head (1) is made of polyethylene, in particular high-density polyethylene, the lower end edge (21) having an oblong shape extending along a major axis (B) in the plane (P) and having two principal vertices (211) at each end of the major axis (B);and in that the wall of the flexible skirt (60) has a thickness between 150 µm and 400 µm, and the head (1) is made of polyethylene (PE) or high-density polyethylene (HDPE), said tube head (1) having a height (hl) between 5 and 20 mm, in particular between 8 and 12 mm, and the length (d) of the tube head (1) along its major axis (B) is between 15 and 75 mm, in particular between 30 and 50 mm, the ratio d / hl being between 2 and 6, in particular between 3 and 5.;

2. Tube (100) according to the preceding claim, characterized in that the skirt (60) is made of a multilayer material comprising an outer layer (62) of polyethylene, an intermediate barrier layer (63) of EVOH, and an inner layer (64) of polyethylene.

3. Tube (100) according to any one of the preceding claims, characterized in that the flexible wall (60) has a thickness between 250 pm and 350 pm.

4. Tube (100) according to any one of the preceding claims, characterized in that the distribution orifice (2) is arranged in the center of the upper wall (10).

5. Tube (100) according to any one of the preceding claims, said tube head (1) comprising a hinged cover (11) connected to the head (1) of tube by a hinge (12) and movable between an open position and a closed position, said tube head (1), the hinged cover (11) and the hinge (12) being made of a single piece.

6. Tube (100) according to claim 5, wherein the tube head (1) is configured so that, when the cover (11) is in the closed position, the head (1) has a flat upper surface.

7. Tube (100) according to any one of claims 5 and 6, wherein the lid (11) includes a tab (13) to facilitate opening the lid by a user's finger.

8. Tube (100) according to any one of the preceding claims, wherein the material thickness at the level of the first upper wall (10) and the second annular lateral wall (20) is between 0.3 and 2mm, in particular between 0.5 and 1mm.

9. Tube (100) according to any one of the preceding claims, characterized in that the head (1) comprises an integrity indicator (5)

10. Tube (100) according to the preceding claim, characterized in that the integrity indicator comprises a self-adhesive tab which is glued straddling the cover (11) and the side wall (20), the tab having a pre-cut forming a break initiation arranged along a joint plane between the cover and the side wall.

11. Tube (100) according to claim 9, characterized in that the integrity witness (5) comprises an axially projecting tab (51) made in one piece with a first associated element among the cover (11) or the side wall (20), one free end of the tab (51) being fixed to the other among the cover (11) or the side wall (20), the tab (51) having a break initiation (55) arranged along a joint plane (54) between the cover (11) and the side wall (20).

12. A method for manufacturing a tube (100) according to any one of the preceding claims, characterized in that the skirt (60) is obtained by extrusion.

13. Method of manufacturing a tube (100) according to any one of claims 1 to 11, characterized in that the skirt (60) is obtained by welding two edges of a laminated sheet.

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