Patent Application
20220332098
The invention relates to a laminated material for forming a container. The invention also relates to a flexible tube skirt comprising said laminated material.
Nowadays, the worldwide plastic production represents one of the biggest waste sources. The consumption and the recycling of these plastic products is a major concern for national and regional organizations. The non-recycled plastic materials are currently disposed of by a variety of processes from landfill disposal to energy recovery through thermal and chemical treatments.
In the case of cosmetic packaging industry, laminated materials comprising several plastic layers are widely used as they represent advantages in terms of product protection and mechanical properties.
Some alternatives to plastics are studied in many technical fields. In the field of cosmetics packaging, it has already been envisaged to replace some plastic layers with a paper layer. As the paper is easily recyclable, the presence of a paper layer improves the recyclability of the laminated material. The thicker the paper layer, the higher the proportion of paper in the laminate and the more recyclable the laminate. However, the presence of a paper layer in the laminate has certain drawback.
A first drawback of the use of paper lies in the fact that the paper layer promotes delamination. In case of a laminate material used to form a tube skirt, this delamination is especially promoted in the region of the junction between a tube head and the skirt.
A conventional technique for forming a tube skirt is to overlap the edges of a laminate sheet and compress this overlapping region to form a longitudinal side seam. A second drawback of the presence of a paper layer in the laminate material is that, when forming the side seam, it is not possible to compress and heat as much as with plastic laminate since the paper has a lower compression ratio than usual plastic layers.
The present invention attempts to solve at least one of the above mentioned problems and propose a laminated material for forming a flexible container, said laminated material comprising one or several polymeric layers and at least two paper layers.
In such laminated material, the applicant discovered that for the same amount of paper in mass in the laminated material, multiplying the number of layers of paper helps to limit the delamination of the laminated material. Therefore, It is possible to increase the paper quantity in the laminated material and thus improving the recyclability of the material without causing delamination.
The invention can also comprise any of the following features taken individually or in any technically possible combination:
The invention also relates to a tube skirt made of the laminated material as described above, said tube skirt comprising an overlap side seam and at least a sealing strip at the level of the overlapping region.
The invention can also comprise any of the following features taken individually or in any technically possible combination:
The invention also relates to a tube comprising the tube skirt as described above, in which the paper represents at least 50% in mass of the tube.
The invention will be better understood thanks to the following description which is only indicative and which is not intended to limit said invention, accompanied with the following figures:
In the context of the invention, the following definitions and abbreviations are used. As used herein, the terms “outer”, “inner”, “upper” and “lower”, and the like, used with respect to the various layers refer to the laminated 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.
The term “container” is used herein to refer to an item which may contain a product. Such products are usually liquids, gels or pastes. Preferred containers include tubes and pouches. The container may further comprise a lid or a cap and, if necessary, attachment means for the lid or cap (such as a tube head or shoulder) before it forms a useful commercial container. As a consequence, the laminated material of the invention can form a tube skirt, an insert of a tube head or a combination thereof.
The term “flexible laminate” as used herein describes a laminate 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.
The term “adhesive layer” refers to a layer which is placed between two layers with the object of ensuring that the two layers are joined together.
The term “polymer” refers to a large molecule, or macromolecule, composed of many repeated subunits.
The term “polyolefin” refers to any of a class of polymers produced from a simple olefin as a monomer.
The term “PP” refers to polypropylene.
The term “PE” refers to polyethylene.
As illustrated in
For the same amount of paper in mass in the laminated material, multiplying the number of paper layers involves a diminution of the thickness of said paper layers. The applicant discovered that reducing the thickness of the paper layers allows to reduce the delamination of laminated material 1.
Indeed, when forming the laminated material and when forming a tube skirt from said laminated material, the paper layers of laminated material may undergo mechanical stress which can lead to delamination issues. When a layer of paper of a given thickness is replaced by a plurality of paper layers of lower thickness, the mechanical stress originally undergone by the single paper layer is distributed over the different paper layers of reduced thickness and reduced in each layer under a given threshold under which delamination issues can be more easily avoided.
As exposed above, the paper layers may promote delamination. In case of a laminate material used to form a tube skirt, this delamination is especially promoted in the region of the junction between a tube head and the skirt as the laminated material forming the tube skirt is folded on its inner side. The invention allows reducing the delamination issues, especially during the manufacturing of the tube skirt.
In the context of the invention, the addition of a new layer of paper does not consist in adding paper material in the laminated material but rather in better distributing a given quantity of paper.
The polymeric layers 10 can comprise any polymer suitable for their use in the field of cosmetic packaging such as PE and PP. Advantageously, the polymeric layers all comprise PE. More advantageously, the polymeric layers are made of PE, especially LDPE (low density polyethylene).
Advantageously, the laminated material 1 comprises at least one barrier layer 20. The barrier layer 20 can comprise any material suitable for the their use in the field of cosmetic packaging. Advantageously, the barrier layer 20 comprise aluminum. More advantageously, the barrier layer 20 comprise EVOH.
Advantageously, the laminated material 1 may comprises adhesive layers 40 or tie layers, especially to establish contact between the barrier layer 20 and a neighboring layer. The adhesive layer 40 can comprise any adhesive suitable for this use, such as EAA (Ethylene Acrylic Acid).
Advantageously, the paper layers represent at least 60% in mass of the laminated material. More advantageously, the paper layer represents at least 70% in mass of the laminated material. Such a ratio of paper in the laminated material 1 allows a good recyclability of said laminated material.
Preferably, each paper layer 30 has a thickness comprised between 100 and 200 μm. A paper layer 30 having a thickness of less than 100 μm will be sensitive and its manipulation during the manufacturing of the laminated material 1 will be complex. A paper layer 30 having a thickness of more than 200 μm will be easily and safely handled during the manufacturing of the laminated material 1 but will involve delamination issues, especially when folded. Thus, a paper layer 30 having a thickness comprised between 100 and 200 μm allows safe manipulation and decreases the delamination issues.
The total thickness of the paper layers depends on the thickness of each paper layer 30 and on the number of paper layers 30. Advantageously, the total thickness of the paper layers 30 is comprised between 200 μm and 400 μm.
Preferably, the total thickness of the laminated material is comprised between 300 and 450 μm. This range of thickness allows good mechanical properties for a laminated material 1 comprising around 70% of paper in mass.
Advantageously, the total thickness of the paper layers 30 represent more than 50% of the total thickness of the laminated material 1. More advantageously, the total thickness of the paper layers 30 represent more than 70% of the total thickness of the laminated material 1. Such a ratio of paper in the laminated material 1 allows a good recyclability of said laminated material 1 while keeping good mechanical properties.
Preferably, as represented in the
In the same way, The term “outer” paper layer does not mean that there can't be any layers above said outer paper layer 32. The outer paper layer 32 is the first layer of paper starting from the upper surface of the laminated material 1.
Advantageously, according to the embodiments represented at the
When forming a tube 200, a tube skirt 100, made from the laminated material 1, is fixed to a tube head 150 as represented in
A paper layer having a higher grammage will be more subject to mechanical stress. Advantageously, the grammage of the inner paper layer 31 is inferior to the grammage of the outer paper layer 32. This configuration helps to reduce the delamination issues.
These delamination issues can be further reduced by controlling other features such as the contact surface between paper and polymer.
Advantageously, according to the embodiment represented at the
Alternatively, according to this embodiment, the paper layers 30 have the same thickness. Still according to this embodiment, the paper layers 30 advantageously have the same grammage.
Preferably, the paper layers 30 are separated by at least one polymeric layer 10. The presence of a polymeric layer 10 between paper layers 30 allows to avoid paper/paper contact which could lead to delamination issues.
Advantageously, at least one paper layer 30 is sandwiched by polymeric layers 10. The paper layer 30 being sandwiched by polymeric layers 10, the contact surface between the paper and the polymer is increased.
More advantageously, all the paper layers 30 are sandwiched by polymeric layers 10. In the same way, this configuration further increases the contact surface between the paper and the polymer. This configuration can be seen at the
The applicant discovered that, when the contact surface between the paper and the polymer is increased, the cohesion of the laminated material 1 is improved. This reduces the delamination issues.
In a preferred embodiment, the laminated material 1 comprises at least two polymeric layers 10 and at least two paper layers 30, said paper layers representing at least 70% in mass of the laminated layer, the thickness of each paper layer being comprised between 100 and 200 μm.
In the context of the invention, if a thicker laminated material is wanted for a specific use, the thickness increasing is not realized by using thicker paper layers but rather by adding a new paper layer of substantially the same thickness, which is advantageously comprised between 100 and 200 μm.
The following structures are exemplary embodiments of laminated materials according to the present invention. The invention is not restricted to the specific laminated material of the exemplary embodiments but encompasses other laminated material structures falling within the scope of the appended claims.
The different layers of these exemplary embodiments of laminated material are described starting from the external layer, i.e. the intended outer surface uppermost, to the internal layer, i.e. the intended inner (product-contacting) surface lowermost. Examples 1 to 4 respectively correspond to
The total thickness of the laminated material according to this embodiment is 415 μm.
The total thickness of the laminated material according to this embodiment is 445 μm.
The total thickness of the laminated material according to this embodiment is 463.5 μm.
The total thickness of the laminated material according to this embodiment is 685 μm.
As represented at
When forming a tube skirt, a sheet of laminated material is cylindrically rolled. Opposite edges of said sheet are overlapped in order to form an overlapping region 110. Said overlapping region 110 is then compressed and heated in order to form an overlap side seam 120. As represented at
However, when using a laminated material 1 comprising a paper layer 30, it is not possible to compress and heat as much as with plastic laminate since the paper has a lower compression ratio than usual plastic layers. The compression needed to form the overlap side seam 120 might damages the paper.
The thicker the paper layer, the more sensitive the paper will be to compression. When a paper layer is compressed, the paper structure can be altered and degraded. For a same level of compression, this alteration is more important with thicker paper layer. Therefore, by multiplying the number of paper layers and thus by reducing the thickness of said paper layers, the resistance to compression of the laminated material is improved and the paper will be less altered.
However, in case of a high percentage of paper in the laminated material, the maximal allowable compression might not be enough to securely seal the skirt. It thus might be necessary to secure the sealing of the skirt. Furthermore, due to this low compression, the tube skirt 100 might comprises, in the overlapping region, a discontinuity 105 in the shape of a step at least in the inner side of the skirt, which makes joining the tube head to said tube skirt problematic. During this assembly step, said discontinuity 105 generates defects in the manufactured packaging, such as leaks or visible defects, making it unsuitable for sale.
Advantageously, the tube skirt 100 comprises at least a sealing strip 130 at the level of the overlapping region 110. This sealing strip 130 secures the sealing of the tube skirt 100, removes the discontinuity 105 in the internal surface at the side seam 120 and makes it easier to join the tube head 150 to said tube skirt 100.
The sealing strip 130 represents a small percentage in mass of the tube skirt 100. The sealing strip is either a monolayer or a multilayer strip.
Said sealing strip 130 also protects the edges of the laminated material sheet in the overlapping region. This aspect is especially relevant for the paper layers 30 as their edges are particularly sensible.
Preferably, as represented at
Advantageously, the overlap side seam 120 has a width (w) of at most 0.5 mm. As the sealing is already secured by at least one sealing strip 130, it is not necessary to form a large overlapping region 110. Reducing the width (w) of the overlapping region allows to save material. At an industrial scale, this small amount of saved material is particularly relevant.
More advantageously, the sealing strip 130 have a width comprised between 3 and 5 mm. This allows to cover the entire overlapping region 110 and the discontinuity 105. The sealing of the tube skirt 100 is thus improved.
Preferably, the sealing strips 130 comprise PE and EVOH. The PE is a sealable material allowing a good sealing of the skirt 100 and a good sealing with the tube head 150. The EVOH has good barrier properties and thus ensure the barrier effect at the level of the side seam 120.
This aspect of the invention is not limited to the laminated material described above with several layers of paper. Indeed, such overlapping region can be used with laminated material for forming a flexible container having one or several paper layers.
According to this aspect, the invention concerns a tube skirt formed by a rolled up sheet of laminated material comprising two opposite edges, said tube skirt comprising an interior side, an exterior side and a longitudinal overlap side seam overlapping the edges of the sheet, said tube skirt comprising a first sealing strip covering the overlap side seam at the interior side of the tube skirt and a second sealing strip covering the overlap side seam at the exterior side of the tube skirt
The tube skirt according to this aspect of the invention can also comprise any of the following features taken individually or in any technically possible combination:
As represented at
| Number | Date | Country | Kind |
|---|---|---|---|
| 19306112.4 | Sep 2019 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/075915 | 9/16/2020 | WO |
