Plastic tube multi-layer structure

Abstract

The present invention relates to a tubular body (1) obtained by an extrusion and labeling process comprising the following successive steps: (a) forming a partially or completely tubular label (3) from a film mainly containing resin; (b) continuously introducing the label (3) into a calibration element; (c) continuously extruding or co-extruding a layer (2) onto the concave side of the label (3), said layer mainly containing resin and the resin of the extruded layer (2) being of the same type as the resin of the label (3); and (d) continuously bringing the layer (2) into contact with the concave surface of the label (3), step (c) being carried out within the calibration element while the label is passing through the calibration element.

Description

Corresponding application

[0001] This application claims priority to European Patent Application No. 22183206.6, filed on July 5, 2022, in the name of AISAPACK HOLDING SA, the content of which is hereby incorporated by reference in its entirety into this application.

Technical Field

[0002] The present invention relates to the field of tubular packaging materials, in particular to the field of flexible tubes for liquid or viscous products. More precisely, it relates to recyclable labeled flexible tubes manufactured by the extrusion and labeling processes described in International Publication No. WO 2015 / 159234, International Publication No. WO 2018 / 051235 and International Publication No. WO 2018 / 203210, the content of these publications, in particular the processes described therein, being hereby incorporated by reference in their entirety into this application.

Background Art

[0003] Cylindrical bodies produced by extrusion and labeling are used to produce unsealed labeled packaging materials such as flexible tubes for liquid or viscous products or cartridges for adhesives or mastics. These packaging materials and their manufacturing method by extrusion and labeling are described in the above-mentioned publications.

[0004] International Publication No. WO 2015 / 159234 describes a process and apparatus for manufacturing these packaging materials by extrusion and labeling, as well as the resulting packaging materials.

[0005] International Publication No. WO 2018 / 051235 describes a manufacturing process in which the label comprises at least two layers, one of which has a melting point at least 20°C higher than the melting point of the extruded cylindrical body.

[0006] WO 2018 / 203210 describes a flexible skirt obtained by extrusion and labeling, which exhibits elastic behavior, i.e., it recovers its initial shape after deformation. The skirt is characterized by a label with a tensile strength greater than 3500 N / mm 2 and an extruded layer with a tensile strength less than 1200 N / mm 2 .

[0007] Prior art publications, in particular those mentioned above in this specification, do not teach a method of producing a recyclable packaging material by extrusion and labeling. In particular, the prior art does not teach manufacturing a cylindrical body by extrusion and labeling using a label and an extruded body formed using resins of the same family, and enabling its recycling. For example, in WO 2015 / 159234, a plurality of materials are mentioned for the extruded parts and the label. In its specific implementation, the label includes at least one layer with a melting point exceeding 160°C and at least one layer of the same type as the extruded cylindrical body. More precisely, in the example, for a polyethylene (PE) cylindrical body, PET / PE, PE / PET / PE, PA / PE, Alu / PE, PE / Alu / PE, Papier / PET / PE labels are used. These structures cannot be easily recycled due to the mixture of materials used to make them. The same problem of material mixing is encountered in WO 2018 / 051235 in the same combination, which makes recycling difficult and requires prior separation of the layers.

[0008] The same problem occurs in WO 2018 / 203210, which describes a mixture of different materials for the main layer.

[0009] Therefore, there is a need to develop a process and means that enable obtaining a packaging material that can be recycled in a simple way for most or all of its end-of-life, without treating the preliminary packaging material before recycling, for example, separating its layers or its components (body, label, shoulder, cap, etc.). SUMMARY OF THE INVENTION

[0010] The present invention overcomes the above-mentioned drawbacks by proposing an easily recyclable cylindrical body produced by extrusion and labeling. The cylindrical body according to the present invention in one embodiment is manufactured by the process described in the above publication, the content of which is incorporated herein by reference. For example, in an embodiment of the present invention, the process from International Publication No. 2015 / 159234 is used, and the cylindrical body is formed by the following successive steps: (a) forming a partially or wholly cylindrical label from a film composed of recyclable resin; (b) introducing the label into a calibration element; (c) extruding a layer onto the concave side of the label; (d) bringing the layer into contact with the concave surface of the label and is obtained by an extrusion and labeling process in which step (c) is carried out within the calibration element.

[0011] The above publication is incorporated herein by reference in its entirety when the methods described therein are relevant.

[0012] Generally speaking, the present invention may be used to increase productivity because the melted and extruded material no longer directly contacts the surface of the calibration element. The friction of the melted and extruded material on the calibration element encountered in a standard extrusion process is eliminated, and as a result, the manufacturing speed can be increased.

[0013] The packaging material resulting from this manufacturing process provides a very high cohesiveness between the label and the cylindrical body. The risk of the label peeling off during use of the packaging material is eliminated in contrast to the prior art packaging materials manufactured using adhesive labels later attached to the extruded body.

[0014] The present invention also enables the production of decorated tubes with small or large diameters. It provides very high flexibility and may be used with new extrusion equipment or allows for the modification and adaptation of existing equipment.

[0015] The principles of the present invention and its embodiments are defined in the appended claims at the end of this specification.

[0016] According to one embodiment, the present invention comprises the following successive steps: (a) forming a partially or fully tubular label from a film mainly containing resin; (b) continuously introducing the label into a calibration element; (c) continuously extruding or co-extruding a layer on the concave side of the label, the layer mainly containing resin and the resin of the extruded layer being of the same type as the resin of the label; (d) continuously bringing the layer into contact with the concave surface of the label and an extrusion and labeling process, wherein step (c) is carried out within the calibration element while the label is passing through the calibration element and the content of the same type of resin is more than 70%, relating to a tubular body obtained by the extrusion and labeling process.

[0017] According to one embodiment, the present invention comprises the following successive steps: (a) forming a partially or fully tubular label from a film mainly containing resin; (b) continuously introducing the label into a calibration element; (c) continuously extruding or co-extruding a layer on the concave side of the label, the layer mainly containing resin and the resin of the extruded layer being of the same type as the resin of the label; (d) continuously bringing the layer into contact with the concave surface of the label and includes an extrusion and labeling method, wherein step (c) is carried out within the calibration element while the label is passing through the calibration element and the same type of resin is more than 70%.

[0018] According to an embodiment of the present invention, the label and the extruded material forming the cylindrical body mainly contain the same type of resin in order to enable recycling of the packaging material at the end of its life.

[0019] According to an embodiment of the present invention, the cylindrical body is mainly based on the same type of resin that enables recycling, and the content of the same type of resin in the cylindrical body with a label is preferably more than 85%, preferably more than 95%.

[0020] In an embodiment, the cylindrical body is mainly based on polyethylene, and the content of polyethylene in the cylindrical body with a label is more than 70%, preferably more than 85%, preferably more than 95%.

[0021] In an embodiment, the cylindrical body is mainly based on HDPE, and the content of HDPE in the cylindrical body with a label is more than 70%, preferably more than 85%, preferably more than 95%.

[0022] In an embodiment, when the cylindrical body is recycled together with an HDPE bottle, the cylindrical body 1 mainly contains HDPE, and its mass flow rate, that is, its MFR (measured according to ISO 1133 at 190 °C, 2.16 kg) is less than 4, preferably less than 1.

[0023] In an embodiment, the cylindrical body is mainly based on polypropylene, and the content of polypropylene in the labeled cylindrical body is more than 70%, preferably more than 85%, preferably more than 95%.

[0024] In an embodiment, the cylindrical body is made at least partially from recycled resin. The cylindrical body may include one or more layers of recycled resin. For food compatibility reasons, it is generally recommended to prevent the recycled layer from forming the inner layer of the packaging material and being in contact with the product being packaged.

[0025] In an embodiment, the cylindrical body with a label is made from recycled polyethylene, and the content of recycled polyethylene is more than 30%, preferably more than 50%, preferably more than 70%.

[0026] In an embodiment, the labeled cylindrical body is made of recycled polypropylene, and the content of recycled polypropylene is more than 30%, preferably more than 50%, suitably more than 70%.

[0027] According to the present invention, in an embodiment, the outer surface of the labeled cylindrical body has a coefficient of friction on stainless steel of less than 0.25, preferably less than 0.2, suitably less than 0.17 (standard ISO8295).

[0028] According to the present invention, in an embodiment, the cylindrical body preferably has a change in thickness at the level of the inner surface that is aligned with the edge of the label, and the change in thickness forms a bead or a recess.

[0029] In an embodiment, the change in thickness forms a bead, and the thickness of the bead is 1% to 30% of the total thickness, preferably 5% to 20% of the total thickness.

[0030] According to the present invention, the bead makes it possible to increase the circumferential strength of the cylindrical body at the level of the discontinuity caused by the edge of the label.

[0031] In an embodiment, the change in thickness forms a recess, and the depth of the recess is 1% to 30% of the total thickness, preferably 5% to 20% of the total thickness.

[0032] According to the present invention, the recess makes it possible to reduce the circumferential strength of the cylindrical body at the level of the edge of the label and facilitate opening the cylindrical body at the end of its life.

[0033] According to the present invention, in an embodiment, the width of the bead or the recess is 0.5 mm to 10 mm, preferably 1 mm to 5 mm.

[0034] In an embodiment, a plurality of edges of the label are arranged with ends connected to each other and separated by a gap of 0 to 2 mm, preferably 0 to 500 microns, suitably 0 to 100 microns.

[0035] In an embodiment, a plurality of edges of the label overlap to form an overlap of 0 to 2 mm, preferably 0 to 500 microns, suitably 0 to 100 microns.

[0036] In an embodiment, the strip located between the label and the extruded resin connects a plurality of edges of the label, and the width of the strip is 2 mm to 10 mm, preferably 3 mm to 7 mm.

[0037] In an embodiment, the strip located on the outer surface of the cylindrical body connects a plurality of edges of the label, and the width of the strip is 2 mm to 10 mm, preferably 3 mm to 7 mm.

[0038] According to the present invention, in an embodiment, the cylindrical body preferably includes a barrier layer against oxygen and / or odor and / or substances that can move into the packaging material.

[0039] The cylindrical body according to the present invention has high resistance to stress cracking and provides a strong barrier against water vapor or oxygen.

[0040] In an embodiment, the extruded layer is preferably made of a resin or a mixture of resins that are particularly resistant to stress cracking. The MFR (measured according to standard ISO1133 at 190 °C, 2.16 kg) of the resin or the mixture of resins forming the layer is less than 50, preferably less than 25, suitably less than 4.

[0041] In an embodiment, the thickness of the cylindrical body is preferably 150 to 1500 microns, particularly 200 to 1200 microns.

[0042] In an embodiment, the thickness of the label is 10 to 120 microns, preferably 20 to 80 microns. Of course, other dimensions are also possible. The label 3 preferably covers the entire surface of the cylindrical body.

[0043] The cylindrical body according to the present invention preferably provides an excellent barrier against water vapor and oxygen. The barrier of the cylindrical body against water vapor is less than 0.1 g / tube / day / 100% H2O, preferably less than 0.05 g / tube / day / 100% H2O. The cylindrical body also has an oxygen permeability of less than 6 cm 3 / tube / day / bar, preferably less than 0.75 cm 3 / tube / day / bar. The barrier against oxygen is preferably provided by a label. There are many solutions for imparting barrier properties against oxygen. The label may include, for example, a biaxially oriented or metallized layer, or a layer having a SiOx coating. Other barrier layers such as EVOH and PA layers widely used in the packaging field may also be used as long as these layers do not reduce the recyclability of the cylindrical body due to their properties or their proportions.

[0044] In an embodiment, the labeled cylindrical body includes at least one barrier layer located within the label, and the thickness of the barrier layer occupies less than 10% of the total thickness, preferably less than 5%, preferably less than 1%.

[0045] In an embodiment, the labeled cylindrical body includes at least one barrier layer located within the extrusion layer. According to the present invention, the thickness of the barrier layer occupies less than 10% of the total thickness, preferably less than 5%, preferably less than 2%.

[0046] In an embodiment, the barrier layer may be a layer of EVOH resin or a metallized layer or a SiOx layer.

[0047] The present invention provides several advantages related to the appearance of the cylindrical body and thus the appearance of the packaging material. By changing the selection of the label, particularly the varnish layer on the surface of the label, it is possible to produce a glossy or matte cylindrical body surface.

[0048] According to the present invention, a complete decoration of the cylindrical body can be obtained. According to an embodiment of the present invention, the label extends in the radial direction over the entire circumference of the cylindrical body. The label can be attached so as to completely surround the cylindrical body in the circumferential direction without leaving a gap between the edges of the label. Therefore, it is possible to create a continuous pattern or unbroken text extending around the body of the cylindrical body without a visible joint between the edges of the decorated label.

[0049] It may also be suitable for the decoration of the label to cover the entire axial direction of the cylindrical body.

[0050] In an embodiment, the present invention relates to a product such as a packaging material including at least one cylindrical body as defined in the present application. The product can be a tube or a bottle or a cartridge or any other form of packaging material or any other object.

[0051] (Definition of terms used in the disclosure of the present invention) The following terms and abbreviations are used in the disclosure of the present invention. · Label: A thin film including one or more layers and forming the outer surface of the cylindrical body. The outer surface of the label is generally printed and varnished. · PP: Polypropylene · HDPE: High-density polyethylene · EVOH: Ethylene vinyl alcohol · Bead: An increase in the local thickness of the wall of the cylindrical body that coincides with the plurality of edges of the label · Recess: A decrease in the local thickness of the wall of the cylindrical body that coincides with the plurality of edges of the label · Strip: A thin film connecting the plurality of edges of the label

[0052] The present invention will be better understood from the description of its non-limiting embodiments and the accompanying drawings.

Brief description of the drawings

[0053]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0054] The present invention relates in particular to flexible or rigid cylindrical parts of packaging materials, produced by extrusion and labeling and referred to herein as cylindrical bodies.

[0055] The production of recyclable cylindrical bodies, i.e., cylindrical bodies mainly containing the same type of resin (labels and extrusion layers), requires specific properties for the labels in particular. In particular, the coefficient of friction of the outer surface of the label in the tool for producing the cylindrical body must be below a critical value beyond which the production of the cylindrical body becomes impossible or breakage of the label is seen resulting in a high level of defective packaging materials, as determined by experiments.

[0056] According to the present invention, experiments have determined that the outer surface of the label should preferably have a coefficient of friction on stainless steel of less than 0.25, preferably less than 0.2, and suitably less than 0.17, and the coefficient of friction is measured according to standard ISO8295.

[0057] Since the label is located on the surface of the produced cylindrical body, the outer surface of the cylindrical body according to the present invention consequently has a coefficient of friction on stainless steel of less than 0.25, preferably less than 0.2, and suitably less than 0.17, and the coefficient of friction is measured according to standard ISO8295 and according to a value determined by experiments.

[0058] As described above, according to the present invention, the label and the extrusion layer are mainly composed of the same type of resin in order to enable recycling of the packaging material at the end of its life.

[0059] According to the present invention, the label occupies 2% - 30% of the thickness of the cylindrical body, preferably 5% - 15%. Beads are used to compensate for the reduction in properties at the level of the edge of the label, and recesses are used to emphasize the reduction in properties at the level of the edge of the label.

[0060] Figure 1 shows a labeled cylindrical body 1 including an extrusion layer 2 covered by a label 3 whose edges 4a and 4b are arranged end - to - end. The outer surface of the label, which is also the outer surface of the cylindrical body, has a coefficient of friction of less than 0.2 on stainless steel.

[0061] According to an embodiment, the label 3 and the extrusion layer 2 are mainly based on polyethylene, preferably HDPE.

[0062] Example 1: Coefficient of friction of the label on stainless steel: 0.15 Multi-layer structure of Label 3: - HDPE 25 microns (outer surface with printing and varnish) - Binder 5 microns - EVOH 10 microns - Binder 5 microns - HDPE 25 microns Extrusion layer 2 - Thickness 330 microns - Resin HDPE The content of HDPE in the cylindrical body 1 is 95%.

[0063] Therefore, the cylindrical body 1 can be easily recycled through the HDPE recycling channel.

[0064] According to another embodiment, the label includes a layer of recycled HDPE.

[0065] According to another embodiment (Example 2), the label is made of recycled HDPE, and layer 2 is co-extruded to form a multi-layer structure.

[0066] Example 2: Label 3 - Recycled HDPE 70 microns Extrusion layer 2 is multi-layer (co-extruded) - Recycled HDPE 370 microns (layer in contact with the label) - Binder 10 microns - EVOH 20 microns - Binder 10 microns - HDPE 20 microns (inner surface) The proportion of recycled HDPE in the cylindrical body 1 is 88%. The proportion of unused HDPE is 4%. Therefore, the cylindrical body 1 can be easily recycled through the HDPE recycling channel.

[0067] According to other embodiments, the tubular body includes a barrier layer within the label 3 and another barrier layer within the layer 2. This embodiment is particularly suitable for trapping the recycling layer between two barrier layers located near the inner and outer surfaces of the tubular body respectively. With this configuration, molecules present in the recycled resin can be prevented from moving towards the inner surface and the outer surface of the tubular body. The barrier layer is preferably a thin layer such as a metallized layer or a SiOx layer or a layer formed of other equivalent materials.

[0068] Figure 1 shows a bead 5 located on the inner surface of the tubular body 1 and coinciding with the edges 4a and 4b of the label 3. The bead at least partially compensates for the discontinuity in the circumferential characteristics of the tubular body at the level of the edge of the label. In the example shown in Figure 1, the thickness of the tubular body is 400 microns, and the additional thickness caused by the bead is 40 microns, that is, the bead thickness accounts for 10% of the total thickness. In other embodiments of the present invention, the thickness of the bead is equal to the thickness of the label, that is, 60 microns, which corresponds to 15% of the total thickness. According to the present invention, the thickness of the bead varies from 1% to 30% of the total thickness, preferably 5% to 20%.

[0069] The width of the bead 5 is from 0.5 mm to 10 mm, preferably from 1 mm to 5 mm. The bead 5 makes it possible to improve the resistance of the tubular body 1 to rupture, especially in case of impact.

[0070] According to another embodiment of the present invention shown in Figure 2, the tubular body 1 has a local reduction in the thickness of the extruded layer 2 at the level of the edges 4a and 4b of the label 3, forming a recess 5'. The recess 5' has a depth of 1% to 30% of the total thickness of the wall of the tubular body 1, preferably 5% to 20%. The recess 5' increases the vulnerability of the tubular body at the level of the edge of the label and makes it possible to easily tear the tubular body at the end of its life. Thereby, the user can reduce the remaining amount of the product in the packaging before recycling.

[0071] For example, in the case of the wall thickness of a 300-micron cylindrical body, the depth of the 30-micron recess 5' occupies 10% of the thickness of the cylindrical body. To this reduction in thickness is added the discontinuity caused by the edges of the label. The local reduction in the properties of the cylindrical body makes it easier to tear the cylindrical body.

[0072] Figure 3 shows another embodiment of the present invention in which the edges 4a and 4b of the label overlap. In the embodiment shown in Figure 3, the extrusion layer forms a bead 5 that reinforces the area where the edges 4a, 4b of the label 3 overlap.

[0073] The overlap is from 0 mm to 2 mm, preferably from 0 to 500 microns, and suitably from 0 to 100 microns.

[0074] In an embodiment, the edges 4a and 4b of the label 3 are fixed to each other by welding or adhesion. Alternatively, the edges 4a, 4b are not fixed to each other.

[0075] In an embodiment not shown, the cylindrical body 1 is characterized by a recess 5' at the level of its wall at the level of the overlap of the edges 4a, 4b of the label 3.

[0076] Figure 4 shows another embodiment of the present invention in which the internal strip 6 connects the edges 4a and 4b of the label. The strip 6 is preferably welded to the inner surface of the label. Alternatively, the strip 6 is adhered or fixed by other equivalent means. The strip 6 is preferably made using the same or a similar resin as the resin of the label 3 or the extrusion layer 2, so that the cylindrical body can be easily recycled in accordance with the principles of the present invention.

[0077] In the embodiment shown in Figure 4, the extrusion layer 2 forms a bead 5 that reinforces the wall at the level of the edges 4a, 4b of the label 3.

[0078] In an embodiment of the present invention not shown, the cylindrical body 1 is characterized by a recess 5' at the level of its wall at the level of the edges 4a, 4b of the label 3 (as shown in FIG. 2) instead of the bead 5 of FIG. 4, and thus combines the recess 5' with the internal strip 6.

[0079] FIG. 5 shows another embodiment of the present invention in which the external strip 6' connects the edges 4a and 4b of the label 3. The strip 6' is preferably welded to the outer surface of the label 3. Alternatively, the strip 6' is adhered or fixed by other equivalent means. The strip 7 is preferably made of the same or a similar resin as the resin of the label 3 or the extruded layer 2 so that the cylindrical body 1 can be easily recycled according to the principle of the present invention.

[0080] In the embodiment shown in FIG. 5, the extruded layer 2 forms a bead 5 that reinforces the wall at the level of the edges 4a, 4b of the label 3.

[0081] In an embodiment of the present invention not shown, the cylindrical body 1 is characterized by a recess 5' at the level of its wall at the level of the edges 4a, 4b of the label 3 (as shown in FIG. 2) instead of the bead 5 of FIG. 5, and thus combines the recess 5' with the external strip 6'.

[0082] FIGS. 6 to 8 show examples of packaging materials manufactured from the cylindrical body 1 according to the present invention. These packaging materials can be easily recycled.

[0083] Figure 6 shows a flexible tube 7 intended to contain a viscous or pasty product. The tube 7 features a cylindrical body 1 manufactured by extrusion and labeling according to the principles and embodiments of the present invention described in detail above. One end of the cylindrical body is connected to a head 8 that includes an orifice for removing the product contained in the packaging material. The packaging material also includes an opening and closing system schematically represented by a cap 9 that fits the head 8. The cap 9 and the head 8 may form a separable object such as a cap screwed onto a neck, as shown in Figure 6. Alternatively, the closing system 9 and the head 8 may be inseparable. The head 8 and the cap 9 preferably form one and the same object.

[0084] According to the present invention, the flexible tube 7 formed by the cylindrical body 1, the head 8, and the opening and closing system 9 contains mainly the same type of resin in order to enable the recycling of the entire packaging material at the end of its life without the need to separate the components (cylindrical body 1, head 8, and cap 9) forming the packaging material 7. For example, if the cylindrical body 1 manufactured according to the present invention is based on HDPE, it is therefore preferable that the shoulder head 8 and the cap 9 are also based on HDPE.

[0085] Thus, according to the present invention, the content of the same type of resin in the complete flexible tube is at least 75%, preferably more than 85%, and suitably more than 95%.

[0086] According to the principle of the present invention, the outer surface of the flexible tube 7 has a coefficient of friction on stainless steel of less than 0.25, preferably less than 0.2, and suitably less than 0.17 (standard ISO8295).

[0087] Figure 7 shows a bottle intended to contain a viscous or pasty product. The bottle 11 comprises a tubular body 1 manufactured by extrusion and labeling according to the principles and embodiments of the present invention. One end of the tubular body 1 is connected to a head 8 that includes an orifice for removing the product contained in the packaging material. A bottom 12 is fixed to the second end of the tubular body 1. The packaging 11 also includes an opening and closing system schematically represented by a cap 9 that fits onto the head 8. The cap 9 and the head 8 can form two separable objects, such as a cap 9 screwed onto the neck, as shown in Figure 7. The closing system 9 and the head 8 are preferably connected to each other by suitable means (such as a tongue).

[0088] According to the principles and embodiments of the present invention, the bottle 11 comprising the tubular body 1, the head 8, the bottom 12, and the opening and closing system 9 mainly contains the same type of resin in order to enable recycling of the packaging material at the end of its life. For example, if the tubular body 1 manufactured according to the present invention is based on a PP shoulder 8, the bottom 12 and the cap 9 are also based on PP.

[0089] Thus, according to the principles and embodiments of the present invention, the content of the same type of resin in the bottle is at least 75%, preferably more than 85%, and suitably more than 95%.

[0090] According to the principles and embodiments of the present invention, the outer surface of the bottle 11 has a coefficient of friction on stainless steel of less than 0.25, preferably less than 0.2, and suitably less than 0.17 (standard ISO8295).

[0091] Figure 8 shows a cartridge 13 intended to contain a viscous or pasty product such as an adhesive or a mastic. The cartridge 13 comprises a tubular body 1 manufactured by extrusion and labeling according to the invention. One end of the tubular body is connected to a head 8 including an orifice for taking out the product contained in the packaging 13. The orifice is generally made by cutting off the end of the nozzle before use. The sliding bottom 12 closes the second end of the tubular body and slides to take out the product it contains. The packaging 13 also includes an opening and closing system schematically represented by a cap 9 adapted to the head 8. The cap 9 and the head 8 may form two separate objects such as a cap screwed onto the neck, as shown in Figure 8. The closing system 9 and the head 8 are preferably connected to each other by suitable means (e.g., a tongue).

[0092] According to the principles and embodiments of the present invention, the cartridge 13 comprising the tubular body 1, the head 8, the bottom 12 and the opening and closing system 9 is mainly made of the same type of resin in order to enable recycling of the packaging at the end of its life. For example, if the tubular body 1 manufactured according to the invention is based on HDPE, the shoulder 8, the bottom 12 and the cap 9 are also based on HDPE.

[0093] Therefore, according to the present invention, the content of the same type of resin in the cartridge 13 is at least 75%, preferably more than 85%, suitably more than 95%.

[0094] According to the present invention, the outer surface of the cartridge 13 has a coefficient of friction on stainless steel of less than 0.25, preferably less than 0.2, suitably less than 0.17 (standard ISO8295).

[0095] The embodiments described in this application are described as exemplary examples and should not be regarded as limiting the present invention. Other embodiments may employ means or materials equivalent to those described. For example, the embodiments shown in FIGS. 1 to 5 include beads 5 or recesses 5', but the present invention and its principles equally apply to embodiments of a cylindrical body without beads or recesses. Embodiments may also be combined with each other depending on the situation, or the means used in one embodiment may be used in another embodiment. Dimensions are also given as examples or preferred values and may vary depending on the situation. Similarly, the materials shown are shown as exemplary examples, and other equivalent or suitable materials may be assumed.

[0096] This specification mainly refers to a cylindrical body for forming a tube 7, a bottle 11, and a cartridge 13, but of course other uses are also possible within the framework of the present invention, for example, for forming other objects.

Claims

1. The following are the sequential steps: (a) A step of forming a partially or completely tubular label (3) from a film mainly containing resin, (b) The step of continuously introducing the label (3) into the calibration element, (c) A step of continuously extruding or co-extruding a layer (2) on the concave side of the label (3), wherein the layer mainly comprises a resin, and the resin of the extruded layer (2) and the resin of the label (3) are of the same type. (d) The step of continuously bringing the layer (2) into contact with the concave surface of the label (3), An extrusion and labeling process comprising step (c) being performed within the calibration element while the label is passing through the calibration element, A cylindrical body (1) obtained by an extrusion and labeling process, wherein the same type of resin makes up more than 70% of the total.

2. The cylindrical body according to claim 1, wherein the resin is recyclable and / or recycled.

3. The cylindrical body according to claim 1, wherein the cylindrical body (1) is mainly made of polyethylene or HDPE or polypropylene or HDPE having a mass flow rate of less than 4.

4. The cylindrical body according to claim 1, wherein the cylindrical body (1) is made at least partially from recycled resin.

5. The cylindrical body according to claim 1, wherein the outer surface of the label (3) has a coefficient of friction on stainless steel of less than 0.

25.

6. The cylindrical body according to claim 1, wherein the cylindrical body (1) has a change in thickness at an inner surface level that coincides with a plurality of edges (4a, 4b) of the label (3), and the change in thickness forms a bead (5) or a recess (5').

7. The cylindrical body according to claim 6, wherein the thickness of the bead (5) or the depth of the recess (5') is 1% to 30% of the total thickness.

8. The cylindrical body according to claim 6, wherein the width of the bead (5) or the recess (5') is 0.5 mm to 10 mm.

9. The cylindrical body according to claim 1, wherein the multiple edges (4a, 4b) of the label (3) are arranged with their ends connected and separated by a gap of 0 to 2 mm.

10. The cylindrical body according to claim 1, wherein the multiple edges (4a, 4b) of the label overlap to form an overlap of 0 to 2 mm.

11. The cylindrical body according to claim 1, comprising an internal strip (6) located between the label (3) and the extruded resin (2) and connecting a plurality of edges (4a, 4b) of the label (3), wherein the width of the strip (6) is 2 mm to 10 mm.

12. The cylindrical body according to claim 1, further comprising an external strip (6') located on the outer surface of the cylindrical body (1) and connecting a plurality of edges (4a, 4b) of the label (3), wherein the width of the external strip (6') is 2 mm to 10 mm.

13. The cylindrical body according to claim 1, comprising at least one layer that is a barrier to oxygen and / or odors and / or substances that can move into the packaging material.

14. The cylindrical body according to claim 13, wherein the barrier layer is located within the label (3).

15. The cylindrical body according to claim 13, wherein the barrier layer is located within the extruded layer (2).

16. The cylindrical body according to claim 13, wherein the thickness of the barrier layer each accounts for at least 10% of the total thickness of the label of the extruded layer.

17. A packaging material comprising a tubular body as described in any one of claims 1 to 16.

18. The packaging material according to claim 17, which is a tube (7), a bottle (11), or a cartridge (13).

19. The following are the sequential steps: (a) A step of forming a partially or completely tubular label from a film mainly containing resin, (b) The step of continuously introducing the label into the calibration element, (c) A step of continuously extruding or co-extruding a layer on the concave side of the label, wherein the layer mainly comprises a resin, and the resin of the extruded layer and the resin of the label are of the same type. (d) The step of continuously bringing the layer into contact with the concave surface of the label, Step (c) is performed within the calibration element while the label is passing through the calibration element, An extrusion and labeling method wherein the same type of resin makes up more than 70% of the total.