INSERT FOR A TUBE HEAD OF A FLEXIBLE TUBE CONTAINER, ASSOCIATED TUBE HEAD AND FLEXIBLE TUBE CONTAINER

Abstract

 The present invention relates to an insert (6) designed to be arranged in contact with a shoulder (2) of a tube head (1) of a tube container (40) so as to form a barrier between the tube head (1) and a product contained in the tube container (40),
the insert (6) is formed from a multi-layer material (100) comprising an inner layer (101) made of polyethylene, an outer layer (103) made of polyethylene and at least two polymeric barrier layers (105), the multi-layer material (100) comprising at least 50% of high-density polyethylene (HDPE) and the insert (6) being of a different color of the tube head (1).

Description

Technical field of the invention

[0001] The present invention relates to the field of tube container, such as flexible tube container and more specifically to an insert for a tube head of such tube container.

Background

[0002] Tube container, such as flexible tube container, commonly consist of a tube head associated with a flexible skirt, the tube head comprising a neck for removing a product contained in the tube container, while the skirt forms the internal volume of the tube container which is designed to receive a product.

[0003] The skirt is conventionally formed from a multi-layered sheet which is designed to have satisfactory mechanical resistance and sealing properties.

[0004] The tube head is, however, commonly produced by plastics injection, and this may prove to be unsatisfactory for certain applications owing to the very aggressive nature of some products.

[0005] To overcome these issues, several solutions have been proposed. In particular, it is possible to place, in the area of the tube head, an insert, or rondelle, that fits with the inner face of the shoulder of the tube head to form a protective barrier separating the tube head from the product contained in the tube container. The insert thus limits the infiltration and leakage of unwanted components through the tube head, and protects the tube head and the contents of the tube container. This insert can comprise a polymeric layer, such as a layer of ethylene vinyl alcohol (EVOH).

[0006] Such tube head structures are however difficult and costly to manufacture. In particular, it is difficult to position, in particular to centre, the insert so that the shoulder of the tube head is properly protected. The insert must nonetheless be properly positioned. A poor positioning could also lead to significant plastic deformations of the insert and reduce its barrier properties. Extended storage periods of the product could lead to the deterioration of the tube head and/or of the product.

[0007] Some inserts are also known to provide a hermetic closure of the internal volume of the tube container to hermetically preserved the product while it is stored, prior to its first use, which represents a significant part of the overall lifetime of the tube container.

[0008] These inserts comprise a central portion that hermetically closes the neck of the tube head and requires to be cut, perforated and/or pierced when first used.

[0009] In this case the tube head is generally provided with a cap which includes a punch for cutting, perforating and/or piercing the insert and more particularly the central portion thereof.

[0010] In some cases, the cutting and/or perforation of the insert may be defective, which may cause poor distribution and/or contamination of the product with pieces of the insert. Sometimes, the cutting and/or perforation of the insert may be defective, which may cause poor distribution and/or contamination of the product with pieces of the insert.

[0011] It may also happen that the insert which is difficult to cut and/or perforate is torn from the tube head instead of being cut and/or perforated during the first step of opening the central portion of the insert. The tube head is then no longer protected from the product contained in the internal volume of the tube container which can cause its contamination and/or degradation. There is therefore a need for a solution allowing to solve at least some of the disadvantages the above-mentioned drawbacks.

Summary of the invention

[0012] For this purpose, the present invention proposes an insert designed to be arranged in contact with a shoulder of a tube head of a tube container so as to form a barrier between the tube head and a product contained in the tube container,
the insert is formed from a multi-layer material comprising an inner layer made of polyethylene, an outer layer made of polyethylene and at least two polymeric barrier layers, the multi-layer material comprising at least 50% of high-density polyethylene (HDPE) and the insert being of a different color of the tube head.

[0013] The invention thus makes it possible to provide a tube head comprising an insert which forms a barrier which thus protects the body of the tube head from the product which it contains.

[0014] Such inserts comprising polymeric barrier layers make it possible to avoid using conventional metal inserts or at least comprising a metal barrier layer. The risk that the metal layer is in contact with the product contained in the tube container is avoided, and the risk that it oxidizes said metal layer, in particular at the level of an outer peripheral edge and/or at the level of an inner peripheral edge after the first opening / cutting.

[0015] Combined to such a proportion of HDPE makes it possible to have an insert having adequate barrier properties to protect the tube head of the product contained in the tube container while having an insert resistant to deformation, particularly during its positioning and/or fixing. on the tube head.

[0016] Furthermore, detection of the insert in relation to the tube head is made easier due to the difference of color between the insert and the tube head, particularly by the inspection machine when it is placed in the tube head. The positioning and the centering of the insert are thus made easier.

[0017] According to an aspect of the invention, said insert comprises a central portion and a peripheral region, said central portion forming a non-perforated disc which is designed to seal a neck of the tube head, and said peripheral region being arranged in contact with a complementary surface of the shoulder of the tube head.

[0018] The HDPE adds stiffness to the multi-layer material that it is easier to be cut and/perforated, particularly by a punch during the first use. If the multi-layer material has less stiffness, then it will be more flexible / pliable and therefore will not be cut by the punch before the first use. HDPE also helps to improve moisture barrier, which in-turn helps to improve the oxygen barrier of the polymeric barrier layers, such as EVOH barrier layers. The polymeric barrier layer can be highly moisture sensitive and oxygen barrier is drops significantly when the barrier layer is exposed to moisture/humidity. Having HDPE instead of other polyethylene (linear low-density polyethylene, low density polyethylene, etc), helps to improve the humidity barrier and therefore maintain high level oxygen barrier for the insert.

[0019] According to various embodiments, which may be taken together or separately:

• the tube container is a flexible tube container,
• the multi-layer material comprising at least 55% of high-density polyethylene,
• the insert comprises a central orifice in alignment with the neck and defining an internal edge,
• each polymeric barrier layer is made of EVOH,
• the multi-layer material comprises an adhesive layer between the polymeric barrier layers and the inner layer and/or between the polymeric barrier layers and the outer layer,
• the multi-layer material comprises adhesive layers on both side of each polymeric barrier layer,
• at least one of the adhesive layers is made of a different color of the tube head,
• an outer adhesive layer is made of a different color of the tube head,
• the outer layer comprises high density polyethylene,
• the inner layer comprises high density polyethylene,
• the multi-layer material comprises an internal layer made of polyethylene,
• the internal layer comprises high density polyethylene,
• the internal layer is made of a different color of the tube head,
• the internal layer comprises at least one sub-layer of polyolefin plastomer (POP),
• the multi-layer material comprises an adhesive layer between the polymeric barrier layers and the internal layer,
• the internal layer comprises colored material,
• the multi-layer material has a symmetrical structure with respect to a median plane of the multi-layer material,
• the total thickness of the multi-layer material is between 75 and 150 µm,
• the total thickness of the multi-layer material is between 90 and 130 µm,
• the total thickness of the multi-layer material is between 100 and 110 µm,
• the outer layer has a thickness between 10 and 30 µm,
• the outer layer has a thickness between 15 and 25 µm,
• the outer layer has a thickness between 15 and 20 µm,
• the inner layer has a thickness between 10 and 30 µm,
• the inner layer has a thickness between 15 and 25 µm,
• the inner layer has a thickness between 15 and 20 µm,
• each polymeric layer has a thickness between 5 and 10 µm,
• the adhesive layer has a thickness between 1 and 15 µm,
• the adhesive layer has a thickness between 1 and 5 µm,
• the adhesive layer has a thickness between 2 and 3 µm,
• the adhesive layer has a thickness between 7 and 12 µm,
• the adhesive layer has a thickness between 8 and 10 µm,
• an outer adhesive layer has a thickness between 7 and 12 µm,
• the outer adhesive layer has a thickness between 8 and 10 µm,
• an inner adhesive layer has a thickness between 7 and 12 µm,
• the inner adhesive layer has a thickness between 8 and 10 µm,
• the internal layer has a thickness between 10 and 60 µm,
• the internal layer has a thickness between 25 and 60 µm,
• the internal layer has a thickness between 30 and 50 µm,
• the internal layer has a thickness between 35 and 45 µm,
• the internal layer has a thickness between 10 and 30 µm,
• the internal layer has a thickness between 10 and 20 µm,
• the internal layer has a thickness between 15 and 20 µm,
• the outer layer comprises low density polyethylene (LDPE),
• the inner layer comprises low density polyethylene (LDPE),
• the insert has a truncated cone shape, converging from an outer edge towards a center.

[0020] According to another aspect, the invention relates to a tube head which is designed to be associated with a skirt so as to form an internal volume of a tube container, such as a flexible tube container, said tube head comprising a body, which is made of plastic material, comprising a neck having an opening at a first end, through which opening a product is removed from the internal volume of the tube container, and a shoulder which is joined to a second end of the neck opposite the first end,
said tube head further comprising an insert as described above arranged in contact with the shoulder so as to form a barrier between the body and the product contained in the internal volume.

[0021] According to various embodiments, which may be taken together or separately:

• said insert is arranged substantially perpendicular to a longitudinal axis of the neck,
• the tube head comprises a cap which is designed to be assembled to said neck, said cap comprising a punch which is designed to make a perforation in said insert to produce an opening in the insert, the opening having a cross-section which is less than or equal to the internal cross-section of the neck,

[0022] According to another aspect, the invention relates to a tube container, such as a flexible tube container, comprising a tube head as described above and a flexible skirt associated with said tube head so as to form an internal volume of the tube container, said internal volume being separated from the neck by the insert.

Brief description of figures

[0023] Further characteristics and advantages of the invention will become apparent from the following detailed description, for the understanding of which reference is made to the attached drawings in which:

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

Figure 2 is a cross-sectional view of the tube head shown in Figure 1 and associated with a perforating cap,

Figure 3 is a schematic representation of a tube container according to the present invention,

Figure 4 is a schematic diagram of the layers that form the insert according to a first embodiment of the invention,

Figure 5 is schematic diagram of the layers that form the insert according to a second embodiment of the invention.

Detailed description of the invention

[0024] In the following description, elements with identical structure or similar functions will be referred to by the same reference.

[0025] In the context of the invention, the following definitions and abbreviations are used.

[0026] As used herein, the terms "outer", "inner", "upper" and "lower", and the like, used with respect to the various layers refer to the multi-layer polymeric material with the intended outer or upper surface uppermost and the intended inner or lower (product-contacting) surface lowermost. In addition, these terms and the terms "over", "under" or "on" do not imply that the layers are necessarily directly in contact. For example, the upper layer being "formed on" the barrier layer does not preclude the presence of one or more other intervening layers located between the upper layer and the barrier layer. Furthermore, layers may be provided under the inner layer, i.e. between the inner layer and the product, or above the outer layer (like decorative layers). The term "container" is used herein to refer to an item which may contain a product. Such products are usually liquids, gels or pastes.

[0027] The term "adhesive layer" refers to a layer also called "tie layer" which is placed between two layers with the object of ensuring that the two layers are joined together. The term "tie layer" refers to grafted polyethylene.

[0028] The term "polymer" refers to a large molecule, or macromolecule, composed of many repeated subunits.

[0029] The term "polyolefin" refers to any of a class of polymers produced from a simple olefin as a monomer.

[0030] The term "PE" refers to polyethylene.

[0031] The term "LDPE" refers to low density polyethylene.

[0032] The term "LLDPE" refers to linear low-density polyethylene.

[0033] The term "HDPE" refers to high density polyethylene.

[0034] The term "EVOH" refers ethylene-vinyl alcohol.

[0035] Figure 1 is a cross-sectional view of a tube head 1 according to an aspect of the invention. The tube head 1 comprises a body 11 comprising a shoulder 2 and a neck 3 connected to the shoulder 2.

[0036] The shoulder 2 is connected to a skirt 4 which forms the body of the associated tube container 40 and thus defines an internal volume of the tube container 40.

[0037] The tube container can be a flexible tube container as illustrated in figure 3.

[0038] The term "flexible" as used herein describes a sheet or a container made thereof which can bend or be bent easily and which does not break (unless it is bent too much). Herein in connection with the containers the term flexible indicates that if the container is subjected to a force, for example, by being filled with a liquid, or by applying pressure with a finger or a hand, it will change its form without breaking. A flexible container can also be considered to be a "squeezable" container or a "collapsible" container.

[0039] The neck 3 defines an internal passage 5 which is used for distributing a product contained in the internal volume of the tube container 40.

[0040] The product can be a cosmetic or a pharmaceutic product. Such products are usually liquids, gels or pastes, such as toothpaste, hair dye...

[0041] In the embodiment shown, the neck 3 comprises an external thread 31 which makes it possible for a cap 7 to be screwed onto said neck 3, and a bearing surface which can function as a stop for a cap 7 of this type.

[0042] The tube head 1 is connected to the skirt 4, typically by overmoulding the tube head 1 on the skirt 4, or for example by welding or bonding when joining the skirt 4 to the tube head 1 formed previously, more particularly by injection moulding or by compression injection moulding, or by any other technique.

[0043] The skirt 4 is typically made of plastics material and/or of multi-layer material, for example a multi-layered assembly comprising one or more barrier layers of polymeric material such as EVOH and one or more layers of plastics material, such as polyethylene.

[0044] The tube head 1 further comprises an insert 6 arranged so as to be in contact with, more particularly so as to bear on, the shoulder 2, typically in contact with, more particularly bearing against, a surface of the shoulder 2 oriented towards the internal volume of the tube defined by the skirt 4. The insert 6 is thus arranged in direct contact with the surface of the shoulder 2. The contact can be produced by overmoulding the body 11 of the tube head 1 on the insert 6 which in particular makes it possible to fix the insert 6 to the body 11 of the tube head 1.

[0045] According to the invention, the insert 6 is formed from a multi-layer material 100 comprising an inner layer 101 made of polyethylene, an outer layer 103 made of polyethylene and at least two polymeric barrier layers 105, the multi-layer material 100 comprising at least 50% in weight, preferably at least 55% in weight, of high-density polyethylene (HDPE) and the insert 6 being of a different color of the tube head 1.

[0046] The invention thus makes it possible to provide a tube head 1 comprising an insert 6 which forms a barrier which thus protects the body 11 of the tube head 1 from the product which it contains.

[0047] Such inserts 6 comprising polymeric barrier layers 105 make it possible to avoid using conventional metal inserts or at least comprising a metal barrier layer. The risk that the metal layer is in contact with the product contained in the tube container 40 is avoided, and the risk that it oxidizes said metal layer, in particular at the level of an outer peripheral edge and/or at the level of an inner peripheral edge.

[0048] Combined to such a proportion of HDPE makes it possible to have an insert 6 having adequate barrier properties to protect the tube head 1 of the product contained in the tube container 40 while having an insert 6 resistant to deformation, particularly during its positioning and/or fixing. on the tube head 1.

[0049] Furthermore, detection of the insert 6 in relation to the tube head 1 is made easier due to the difference of color between the insert 6 and the tube head 1, particularly by the inspection machine when it is placed in the tube head 1. The positioning and the centering of the insert 6 are thus made easier.

[0050] HDPE also helps to improve moisture barrier, which in-turn helps to improve the oxygen barrier of the polymeric barrier layers 105. Especially, in case of EVOH barrier layers 105, EVOH is highly moisture sensitive and oxygen barrier is drops significantly when EVOH layer is exposed to moisture/humidity. Having HDPE instead of other polyethylene (linear low-density polyethylene, low density polyethylene, etc), helps to improve the humidity barrier and therefore maintain high level oxygen barrier for the insert 6.

[0051] The insert 6 according to an aspect of the invention comprises a central portion 8 and a peripheral region 9, the central portion 8 forming a non-perforated disc which is designed to seal the neck 3 of the tube head 1, and the peripheral region 9 is arranged in contact with a complementary surface of the shoulder 2 of the tube head 1.

[0052] Thus, advantageously, the peripheral region 9 has a design complementary to the design of the shoulder 2 of the tube head 1. Depending on the shape of the shoulder 2 of the tube head 1, the insert 6 can have a truncated cone shape, converging from an outer edge towards a center.

[0053] In the embodiment shown in Figure 1 and 2, the insert 6 is slightly in a truncated cone shape, particularly on the peripheral region 9.

[0054] As in the embodiment shown in Figure 1 and 2, the peripheral section 9 is mounted so as to be in contact with, more particularly so as to bear against, a complementary surface of the body 11, while the central portion 8 forms a film seal which is designed to seal the neck 3 of the tube head 1 prior to its first use, during which said central portion 8 is perforated at least in part by a punch 12 as set out above.

[0055] The product contained in the tube container 40 is thus protected in a lasting and efficient manner during the storage period thereof prior to use, and this storage period typically represents the majority of the lifetime of the tube container 40.

[0056] The insert 6, and more particularly the central portion thereof, thus forms a film seal which seals the internal volume of the tube container 40 defined by the skirt 4 and protects the product contained in said internal volume.

[0057] Advantageously, the tube head 1 comprising an insert 6 with the central portion 8 closing the neck 3 is typically associated with a perforating cap 7, for example of the type shown in Figure 2.

[0058] The perforating cap 7 as shown is reversible; it has a first end provided with an internal thread 71 which is designed to cooperate with the external thread 31 of the neck 3 and thus to screw the perforating cap 7 to the tube head 1, and a second end provided with a punch 12 which is designed to be inserted into the neck 3 and to perforate all or part of the insert 6, and more specifically all or part of the central portion 8 thereof which seals the neck 3.

[0059] In the cross-section shown in Figure 2, it can be seen that the punch 12 is dimensioned such that when the perforating cap 7 bears against the neck 3, the perforating end of the punch 12 goes beyond the position of the insert 6 in the tube head 1 and can perforate it, thus making it possible for the user to produce an opening which allows the internal volume of the tube container 40 and the internal passage of the neck 3 to communicate in order for the product contained in the internal volume to be dispensed.

[0060] The HDPE adds stiffness to the multi-layer material 100 that it is easier to be cut and/perforated, particularly by a punch 12 during the first use. If the multi-layer material 100 has less stiffness, then it will be more flexible / pliable and therefore will not be cut by the punch before the first use.

[0061] In another embodiment not shown, the insert 6 comprises a central orifice in alignment with the neck 3 and defining an internal edge.

[0062] Inserts 6 according to the invention comprising polymeric barrier layers 105 make it possible to avoid using conventional metal inserts or at least comprising a metal barrier layer. The risk that the metal layer is in contact with the product contained in the tube container 40 is avoided, and the risk that it oxidizes said metal layer, in particular at the level of the outer peripheral edge and/or at the level of an inner peripheral edge after perforation of the insert 6 by the punch 12.

[0063] Advantageously, the multi-layer material 100 is obtained by a blown manufacturing process. In another embodiment, the multi-layer material 100 is obtained from two multi-layer films comprising each a polymeric barrier layer 105 and laminated together.

[0064] Advantageously, the total thickness of the multi-layer material 100 is between 75 and 150 µm more preferably between 90 and 130 µm, and even more preferably between 100 and 110 µm.

[0065] Such a thickness makes it possible to have a good barrier effect and good protection of the tube head 1 and of the product contained in the tube container 40 while having a flexible insert 6 resistant to deformation, particularly during its positioning and/or fixing. on the tube head 1.

[0066] Advantageously, each polymeric barrier layer 105 is made of EVOH. EVOH has good barrier effect with regard to oxygen, moisture and flavors.

[0067] Preferably, each polymeric barrier layer 105 has a thickness between 5 and 10 µm. This thickness is sufficient to ensure the function of barrier layer 105 but without stiffening the insert 6 which may be slightly deformed during its positioning and/or fixing on the tube head 1.

[0068] Advantageously, the outer layer 103 and/or the inner layer 101 comprise HDPE.

[0069] Particularly, the outer layer 103 and/or the inner layer 101 can comprise sub-layers.

[0070] In addition to a sub-layer of HDPE, the outer layer 103 and the inner layer 101 can also comprises a sub-layer of low-density polyethylene (LDPE). The use of LDPE in the inner and outer layers 101, 103 improves the welding of the insert 6 on the tube head 1. Moreover, the LDPE provides flexibility to the insert 6 improving its resistance to deformation, particularly during its positioning and/or fixing on the tube head 1.

[0071] Preferably, the outer layer 103 has a thickness between 10 and 30 µm, more preferably between 15 and 25 µm, and even more preferably between 15 and 20 µm.

[0072] Preferably, the inner layer 101 has a thickness between 10 and 30 µm, more preferably between 15 and 25 µm, and even more preferably between 15 and 20 µm.

[0073] Preferably, in addition to the outer layer 103, the inner layer 101 and the at least two barrier layers 105, the multi-layer material 100 comprises an internal layer 107 made of polyethylene.

[0074] Advantageously, the internal layer 107 has a thickness between 10 and 60 µm.

[0075] In an example, the internal layer 107 has a thickness preferably between 25 and 60 µm, more preferably between 30 and 50 µm, and even more preferably between 35 and 45 µm. In another example, the internal layer 107 has a thickness preferably between 10 and 30 µm, more preferably between 10 and 20 µm, and even more preferably between 15 and 20 µm.

[0076] Advantageously, in an example, the internal layer 107 is made of a different color of the tube head 1. Thus, the internal layer 107 can comprise colored material. For example, the colored material is a colored master batch, such as a blue master batch.

[0077] This makes it possible to have an insert 6 that is differentiable from the tube head 1, which makes it easier to position the insert 6 on the tube head 1.

[0078] The internal layer 107 is advantageously made of a single layer, preferably made of HDPE or of a plurality of sub-layers.

[0079] The internal layer 107 can comprises sub-layers made of HDPE 1071 which facilitates the perforation and/or the cutting of the insert 6 during the first use.

[0080] The internal layer 107 can also comprises at least one sub-layer of polyolefin plastomer (POP) 1072.

[0081] Advantageously, the POP layer 1072 allows the adhesion of the material at the central portion. The polyolefin plastomer (POP) is a lower melting point resin and therefore can be sealed when the material is still hot during the blown manufacturing process, thereby avoiding the lamination step to get two barrier layers 105.

[0082] The internal layer 107 has a thickness between 25 and 60 µm.

[0083] In an example, the internal layer 107 has a thickness between 25 and 60 µm, preferably between 30 and 50 µm, and even more preferably between 35 and 45 µm.

[0084] In another example, the internal layer 107 has a thickness between 10 and 30 µm, preferably between 10 and 20 µm, and even more preferably between 15 and 20 µm.

[0085] To improve cohesion between the different layers, the multi-layer material 100 comprises an adhesive layer 109 between the different layers.

[0086] Thus, an adhesive layer 109 is placed between the polymeric barrier layers 105 and the inner layer 101 and between the polymeric barrier layers 105 and the outer layer 103.

[0087] An adhesive layer 109 is also place between the polymeric barrier layers 105 and the internal layer 107.

[0088] Advantageously, the adhesive layer 109 has a thickness between 1 and 15 µm. Advantageously, in an example, the adhesive layer 109 has a thickness between 1 and 5 µm, preferably between 2 and 3 µm.

[0089] In another example, an outer adhesive layer 1091 and/or an inner adhesive layer 1092 has a thickness between 7 and 12 µm, preferably between 8 and 10 µm.

[0090] The outer adhesive layer 109 is the adhesive layer 109 intended to be directed towards the shoulder 2 of the tube head 1, more precisely it is the adhesive layer 109 between the outer layer 103 and the polymeric barrier.

[0091] The inner adhesive layer 1092 is the adhesive layer 109 intended to be directed towards the inside of the tube, more precisely it is the adhesive layer 109 between the inner layer 1 and the polymeric barrier.

[0092] In another example, the outer adhesive layer 1091 is made of a different color of the tube head 1. Thus, the outer adhesive layer 1091 can comprise colored material. For example, the colored material is a colored master batch, such as a blue master batch.

[0093] This makes it possible to have an insert 6 that is differentiable from the tube head 1, which makes it easier to position the insert 6 on the tube head 1.

[0094] In an example, the multi-layer material 100 has a symmetrical structure with respect to a median plane of the multi-layer material 100.

[0095] For example, the multi-layer material 100 is made up of symmetrical layers. Advantageously, the multi-layer material 100 has a completely symmetrical structure with respect to its median plane, i.e., having symmetrical layers with substantially the same thickness and made up of substantially the same material.

[0096] In another example, the multi-layer material 100 has a symmetrical structure with respect to the internal layer 107. In other words, the layers located on either side of the internal layer 107 have substantially the same thickness and made up of substantially the same material.

[0097] The only difference can be in the color of the layers. For example, an outer layer 103, such as the outer adhesive layer 1091, can be made of a different color of the tube head 1, such as blue and the corresponding inner layer 1, such as the inner adhesive layer 1092, can be made of a color similar to the tube head 1, i.e. made of a different color of the corresponding outer layer 103.

[0098] The symmetry, not only geometric but also in terms of the component material, limits the behavioral heterogeneities of the different layers. The symmetry relative to the median plane of the multi-layer material 100, or to the internal layer 107, makes it possible to compensate differential shrinkage or deformations between layers occurring on one side of the multi-layer material 100 with differential shrinkage or deformations between layers occurring on the other side of the multi-layer material 100.

[0099] Thus, the symmetrical layers have substantially the same thickness and are substantially made up of the same material, but not necessary the same color.

[0100] A first embodiment of the structure of the multi-layer material 100 of the insert 6 according to the invention is illustrated at figure 4.

[0101] It has to be noticed that the figure 4 is schematic representation and that the layers are not at scale.

[0102] The different layers of these exemplary embodiments of multi-layer material 100 are described starting from the outer layer 103, i.e. the layer intended to be in contact with the shoulder 2 of the tube head 1, to the interne layer, i.e. the layer intended to be in contact with the product contained in the tube container 40.

[0103] In this first embodiment, the insert 6 is formed from a symmetric multi-layer material 100 comprising an inner layer 101 made of polyethylene, an outer layer 103 made of polyethylene, two polymeric barrier layers 105 made of EVOH and an internal layer 107 made of polyethylene.

[0104] The EVOH barrier layers 105 are located on either side of the internal layer 107, i.e. between the inner layer 101 and the internal layer 107 and between the outer layer 103 and the internal layer 107.

[0105] The inner and the outer layers 101, 103 comprise three sub-layers: an outer/innermost layer made of an 80:20 mixture respectively of HDPE and LDPE and two sub-layers of HDPE. The internal layer 107 comprises six sub-layers: two blue sub-layers of HDPE 1071, two white sub-layers of HDPE 1071 and two central sub-layers of POP 1072.

[0106] To prevent any delamination problems, the inner layer 101, the outer layer 103 and the internal layer 107 are maintained together with adhesive layer 109.

[0107] Advantageously, the adhesive layer 109 is a 70:30 mixture of respectively LLDPE and maleic anhydride grafted linear LLDPE.

[0108] A second embodiment of the structure of the multi-layer material 100 of the insert according to the invention is illustrated at figure 5.

[0109] It has to be noticed that the figure 5 is schematic representation and that the layers are not at scale.

[0110] The different layers of these exemplary embodiments of multi-layer material 100 are described starting from the outer layer 103, i.e. the layer intended to be in contact with the shoulder 2 of the tube head 1, to the interne layer, i.e. the layer intended to be in contact with the product contained in the tube container 40.

[0111] In this second embodiment, the insert 6 is formed from a symmetric multi-layer material 100 comprising an inner layer 101 made of polyethylene, an outer layer 103 made of polyethylene, two polymeric barrier layers 105 made of EVOH and an internal layer 107 made of polyethylene.

[0112] The EVOH barrier layers 105 are located on either side of the internal layer 107, i.e. between the inner layer 101 and the internal layer 107 and between the outer layer 103 and the internal layer 107.

[0113] The inner and the outer layers 101, 103 comprise only HDPE.

[0114] The internal layer 107 comprises on layer of white HDPE.

[0115] To prevent any delamination problems, the inner layer 101, the outer layer 103 and the internal layer 107 are maintained together with adhesive layer 109.

[0116] Advantageously, the adhesive layer 109 is made of maleic anhydride-modified, linear low-density polyethylene.

[0117] The outer adhesive layer 1091 is a blue layer.

[0118] The thickness of the outer and the inner adhesive layer 1091, 1092 is comprises between 8 and 10 µm.

[0119] The number of sub-layers composing the inner layer 101, the outer layer 103 and the internal layer 107 is not limited to the examples illustrated in the figures 4 and 5.

Claims

1. Insert (6) designed to be arranged in contact with a shoulder (2) of a tube head (1) of a tube container (40) so as to form a barrier between the tube head (1) and a product contained in the tube container (40),
the insert (6) is formed from a multi-layer material (100) comprising an inner layer (101) made of polyethylene, an outer layer (103) made of polyethylene and at least two polymeric barrier layers (105), the multi-layer material (100) comprising at least 50% of high-density polyethylene (HDPE) and the insert (6) being of a different color of the tube head (1).

2. Insert (6) according to the preceding claim, comprising a central portion and a peripheral region, said central portion forming a non-perforated disc which is designed to seal a neck of the tube head (1), and said peripheral region being arranged in contact with a complementary surface of the shoulder (2) of the tube head (1).

3. Insert (6) according to any of the preceding claims, wherein each polymeric barrier layer (105) is made of EVOH.

4. Insert (6) according to any of the preceding claims, wherein the multi-layer material (100) comprises an adhesive layer (109) between the polymeric barrier layers (105) and the inner layer (101) and/or between the polymeric barrier layers (105) and the outer layer (103).

5. Insert (6) according to any of the preceding claims, wherein the outer layer (103) and/or the inner layer (101) comprise high density polyethylene.

6. Insert (6) according to any of the preceding claims, wherein the multi-layer material (100) comprises an internal layer (107) made of polyethylene.

7. Insert (6) according to any of the preceding claims, wherein the multi-layer material (100) has a symmetrical structure with respect to a median plane of the multi-layer material (100) or with respect to the internal layer (107).

8. Insert (6) according to any of the preceding claims, wherein the total thickness of the multi-layer material (100) is between 75 and 150 µm.

9. Tube head (1) which is designed to be associated with a skirt (4) so as to form an internal volume of a tube container (40), said tube head (1) comprising a body (11), which is made of plastic material, comprising a neck (3) having an opening at a first end, through which opening a product is removed from the internal volume of the tube container (40), and a shoulder (2) which is joined to a second end of the neck (3) opposite the first end,
said tube head (1) further comprising an insert (6) according to any of claims 1 to 8 arranged in contact with the shoulder (2) so as to form a barrier between the body (11) and the product contained in the internal volume.

10. Tube head (1) according to the preceding claim, wherein said insert (6) is arranged substantially perpendicular to a longitudinal axis of the neck (3).

11. Tube head (1) according to any of claims 9 or 10, further comprising a cap (7) which is designed to be assembled to said neck (3), said cap (7) comprising a punch (12) which is designed to make a perforation in said insert (6) to produce an opening in the insert (6), the opening having a cross-section which is less than or equal to the internal cross-section of the neck (3).

12. Tube container (40) comprising a tube head (1) according to any of claims 9 to 11 and a flexible skirt (4) associated with said tube head (1) so as to form an internal volume of the tube container (40), said internal volume being separated from the neck (3) by the insert (6).

Drawing