Recoverable standing pouch based on polyethylene

Abstract

A recyclable standing pouch (1) for beverages, based on polyethylene, has a front side (2), a rear side (3) and a bottom (4), where the front side (2), the rear side (3) and the bottom (4) each have a transparent outer layer (5, 10) and a sealing layer (9, 11), characterized in that the sealing layer (9, 11) has a greater thickness than the outer layer (5, 10).

Description

Technical Field

[0001] The present invention relates to a recyclable stand-up bag for beverages, the stand-up bag having a front side, a rear side and a bottom, wherein the front side, the rear side and the bottom have a transparent outer layer and a sealing layer respectively. Background Art

[0002] Stand-up pouches or stand-up bottom pouches are flexible packaging that can stand on their bottom and are typically used for powders, pastes or beverages to be consumed. The lower portion of the stand-up pouch is provided with side gussets to enable the bag to stand.

[0003] In 1963, Doyen disclosed in patent DE 1 281 140 a bag with a thermoplastic bottom, which consists of two film layers connected by a W-shaped inwardly folded bottom part and welded to each other at their edges by longitudinal welds along the bag height.

[0004] Stand-up pouches (SUPs) were first manufactured about 60 years ago. Early designs used a laminate consisting of a polyethylene terephthalate (PET) sublayer and a polyethylene (PE) sublayer. A sublayer of aluminum film might optionally be placed between them. This type of design is still used commercially, with a typical structure having a thin sublayer of PET, approximately 12 μm, a sublayer of aluminum film, approximately 8 μm thick, and a thicker sublayer of polyethylene, approximately 80 μm thick. A problem with these SUP designs is that the bags are very difficult or impossible to recycle due to the different structural materials.

[0005] Meanwhile, it is known to produce recyclable stand-up pouches composed of at least 95% polyethylene, as many recycling facilities are able to recycle coextruded or laminated films having at least 95% polyethylene as pure polyethylene material.

[0006] EP 3 256 317 B1 discloses a laminate structure composed of a polymer material, wherein the laminate structure comprises an outer web and an inner web, the outer web comprising a first A-layer and a second A-layer, the second A-layer comprising polyethylene selected from the group consisting of LLDPE, MDPE, and HDPE, the inner web comprising a first B-layer in contact with the outer web, the first B-layer comprising polyethylene selected from the group consisting of LLDPE and MDPE, and a third B-layer comprising a sealant composition, with the following provisions: the outer web is laminated to the inner web, and the laminate structure is printed at the interface between the outer and inner webs. The HDPE, MDPE, LLDPE, and the sealant polyethylene together constitute at least 95% by weight of the polymer material used to produce the laminate structure, and the first A-layer also comprises an HDPE composition.

[0007] However, polyethylene has several disadvantages that make it difficult to construct a stand-up pouch made solely of polyethylene. Thus, while high-density polyethylene (HDPE) provides the stiffness required for a stand-up pouch structure, the physical and optical properties of HDPE, such as haze and gloss, are relatively unfavorable. In contrast, linear low-density polyethylene (LLDPE) offers excellent physical and optical properties, but poor stiffness. The physical and optical properties of medium-density polyethylene (MDPE) are generally between those of HDPE and LLDPE. Accordingly, a simple stand-up pouch design composed solely of PE does not possess the combination of optical and stiffness properties provided by prior art designs consisting of a sublayer composed of PET and a sublayer composed of PE.

[0008] Currently, packaging films made of plastic are typically laminated structures composed of various sub-layers. Sub-layers made of different plastics are often combined. Packaging is often produced with externally visible printing. The printing is applied to a suitable printable sub-layer of the film laminate, for example, a sub-layer made of biaxially oriented polypropylene or polyethylene terephthalate.

[0009] Continuous printing methods, such as gravure or flexographic continuous printing, are commonly used for high-quality packaging. In these continuous printing methods, the individual printing units are separated from one another, and the printed film web passes through a dryer and multiple deflection rollers before the next color is applied, thereby extending the drying path. However, with certain films, particularly PE films, this can lead to problems with register accuracy or unacceptable printed images. Therefore, PE films and PE film laminates are often printed on so-called central printing cylinder machines in a satellite-based flexographic printing process. Here, the printed film web is guided on a central cylinder between the individual printing units and only then dried. Intermediate drying, which is possible after ink application, also occurs on a central cylinder, with the film web also guided on the central cylinder during drying. However, this generally does not allow for complete drying between printing units due to the very short drying paths. Consequently, print quality in satellite-based flexographic printing is not as high as in continuous printing.

[0010] For high-quality packaging laminates, packaging manufacturers often require film laminates printed using continuous printing methods, such as gravure printing or (UV) flexographic continuous printing, due to the achievable printed image. Therefore, in such film laminates, PET or PP film webs have been used as printed film webs to date, which are then laminated to form the film laminate using a material sealable at low temperatures, such as a PE film.

[0011] Here, for cost reasons, the film lamination structures for the packaging industry should be as thin as possible. This also means that the individual film sub-layers should be implemented as thin as possible according to their functions. The problem with single-layer structures made of polyethylene is that PE films with a technically important thickness of less than 40 μm can usually only be printed on printing facilities in a limited or not at all continuous structure with the required quality, and in particular cannot be printed by intaglio printing methods or flexographic continuous printing methods.

[0012] At the same time, the current ways of producing and processing plastic materials and packaging films can be optimized. The European Union hopes to reduce the landfill of plastic waste within the scope of its "Green Deal". By 2030, 55% of the packaging waste made of plastic will be recycled.

[0013] In order to meet the challenges of recycling, the design of packaging must be constructed more and more sustainably. For example, this can be achieved by adopting and implementing more single-material structures. Here, the challenge lies in achieving the completely different characteristics of packaging with only one recyclable single-material structure, which was previously achieved by combining different plastic sub-layers with different material substrates.

[0014] At the same time, the same mechanical properties of multi-material structures cannot be achieved, which poses new challenges to the design and construction of stand-up pouches, affecting the shape stability and self-standing stability of stand-up pouches. Therefore, due to the change of material properties, it is necessary to accurately obtain the known and characteristic pouch shapes.

[0015] In addition, commercially available stand-up pouches for beverages are filled and sealed under vacuum at temperatures above 85 °C. The single-material structure of the pouch must ensure the implementation of the pouch shape and the closing seal even under hot filling conditions. Summary of the Invention

[0016] The object of the present invention is to provide a recyclable stand-up pouch, which is implemented as a single-material structure and ensures the known typical shape of the stand-up pouch. In addition, the stand-up pouch should meet the requirements of the "Plastic Pact 2025" and be fully recyclable. The stand-up pouch should protect the contents of the pouch from spoilage, ensure long-term and delicious preservation quality and have a high barrier against oxygen and water vapor permeation. The stand-up pouch should be sealable and also suitable for hot filling beverages. In addition, the sides of the stand-up pouch can be printed repeatedly and precisely. The flexible pouch packaging should undoubtedly be healthy and ecologically sustainable. In addition, the stand-up pouch should also have a comfortable feel.

[0017] The above object is ensured according to the present invention by a recyclable stand-up pouch, method and application according to the parallel independent claims. Advantageous variants can be learned from the dependent claims, the description, the embodiments and the drawings.

[0018] According to the invention, the sealing layer has a greater thickness relative to the outer layer.

[0019] The outer layer forms the outer skin of the stand-up pouch and is implemented transparently in order to expose and also protect here the printed image applied by reverse printing.

[0020] Advantageously, the outer layer consists of a uniaxially oriented polyethylene (MDO PE), where the MDO PE is configured to be stretched more than 2.0 times, preferably more than 3.0 times, in particular more than 4.0 times and / or less than 7.0 times, preferably less than 6.5 times, in particular less than 6.0 times. Thus, the advantages of the outer layer in terms of good stiffness and good toughness are ideally constituted, whereby a repetitive and precise printed image can also be applied to a particularly thin outer layer.

[0021] Ideally, the thickness of the outer layer is greater than 10 μm, preferably greater than 14 μm, in particular greater than 18 μm and / or less than 30 μm, preferably less than 26 μm, in particular less than 22 μm. The outer layer is thus constituted as thin as possible and at the same time sufficiently ensures stability, whereby a typical stand-up pouch shape can be achieved.

[0022] Ideally, the outer layer is constituted in multiple layers, where the outer layer has more than two sub-layers, preferably more than three sub-layers, in particular more than four sub-layers.

[0023] For example, the outer layer has a polyethylene share of greater than 92.5 wt%, preferably greater than 95 wt%, in particular greater than 97.5 wt%. This extremely high polyethylene share enables the implementation of a single-material structure for the stand-up pouch and forms the basis for recyclability.

[0024] The inner side of the stand-up pouch is formed by the sealing layer.

[0025] In a particularly advantageous variant of the invention, the sealing layer is formed by a multi-layer cast polyethylene layer. The sealing layer is particularly advantageously suitable for the sealing process.

[0026] Ideally, the thickness of the sealing layer is greater than 40 μm, preferably greater than 55 μm, in particular greater than 70 μm and / or less than 120 μm, preferably less than 100 μm, in particular less than 80 μm. The sealing layer is thus constituted extremely thinly and at the same time ensures the sealing performance of an absolutely tight seal seam.

[0027] Ideally, the sealing layer is constituted in multiple layers, where the sealing layer has more than two sub-layers, preferably more than three sub-layers, in particular more than four sub-layers.

[0028] For example, the sealing layer has a polyethylene share of greater than 92.5 wt%, preferably greater than 95 wt%, in particular greater than 97.5 wt%. This extremely high polyethylene share enables the implementation of a single-material structure for the stand-up pouch and forms the basis for recyclability.

[0029] The outer layer and the sealing layer are preferably connected to the adhesive sublayer and combined to form the front and rear sides of a rectangle. The bottom of the stand-up pouch can in principle have the same structure. In an advantageous variant, the outer layer and the sealing layer of the bottom are configured to be slightly thinner. The front side, the rear side and the bottom of the stand-up pouch are connected by a sealing structure. Here, the rectangular front side and rear side are stacked on top of each other and a bottom folded in a w-shape is placed therebetween.

[0030] In a particularly advantageous variant of the present invention, the thickness of the sealing layer is configured to be more than 2.00 times, preferably more than 2.75 times, in particular more than 3.50 times that of the outer layer. Thereby, favorable sealing properties of the stand-up pouch implemented as a single-material structure are obtained.

[0031] Ideally, the thickness of the sealing layer is configured to be 6.0 times or less, preferably 5.0 times or less, in particular 4.0 times or less that of the outer layer. A sealing layer that is too thick compared to the outer layer adversely affects the sealing characteristics.

[0032] Heat sealing is a common method for manufacturing seams in flexible stand-up pouches. The purpose of sealing is the absolutely tight and also firm polymerization of the sealable materials. Tightness particularly means preventing microbial contamination as well as the ingress of oxygen and water vapor, which as is well known can cause spoilage of foodstuffs and hygroscopic fillings in stand-up pouches. The individual thickness and implementation of the cast polyethylene sealing layer, as well as the sealing process itself, achieve the required absolute tightness of the stand-up pouch.

[0033] In heat sealing, two heated bars are used, which apply a printed pattern to the material to be sealed and at the same time transfer heat to the interface, whereby the material melts and a connection is formed. The printed pattern ensures good contact between the materials and supports the penetration of the melted viscous material at the interface, which viscous material connects permanently and tightly after cooling. Sealability should be understood as the successful and time-efficient process of connecting the front side, the rear side and the bottom to form a stand-up pouch.

[0034] The stand-up pouch according to the present invention discloses a well-considered polyethylene-based single-material structure. Here, the stand-up pouch ideally has a polyethylene share of more than 92.5 wt%, preferably more than 95 wt%, in particular more than 97.5 wt%. The outstanding single-material structure based on polyethylene forms the basis for favorable recyclability and thus complies with the provisions of the EU's "Green Deal". The stand-up pouch according to the present invention with its thickness ratio of the sealing layer to the outer layer achieves completely different characteristics, which were previously only achievable through material combinations and at the same time, in particular through its recyclability, is particularly sustainable.

[0035] In a particularly advantageous variant of the present invention, the front side and / or the rear side and / or the bottom has at least one functional layer, and the at least one functional layer is arranged between the outer layer and the sealing layer. The functional layer is implemented as an ideal barrier against oxygen and water vapor. At the same time, the functional layer provides additional protection for the bag against puncturing.

[0036] Ideally, the functional layer has a thickness of less than 25 μm, preferably less than 20 μm, particularly less than 15 μm and / or has a thickness of greater than 6 μm, preferably greater than 9 μm, particularly greater than 12 μm.

[0037] Preferably, the functional layer has a barrier sublayer and / or a metallized sublayer and / or a metal sublayer and / or an evaporated aluminum sublayer and / or at least one MDO PE sublayer.

[0038] In an advantageous variant, the functional layer is implemented as an MDO PE layer. Preferably, an extremely thin aluminum sublayer is evaporated onto the MDO PE layer. At the same time, the layer is prepared for adhesive lamination. The layer provides excellent barriers against oxygen, odorants and fragrances and has an excellent water vapor barrier.

[0039] For example, the functional layer has a polyethylene share of greater than 92.5 wt%, preferably greater than 95 wt%, particularly greater than 97.5 wt%. The extremely high polyethylene share enables the implementation of a single-material structure as a stand-up pouch and forms the basis for its recyclability.

[0040] In an advantageous variant of the present invention, the MDO PE layer is evaporated, preferably by vacuum evaporation. Here, preferably a metal sublayer, in particular aluminum and / or an aluminum oxide sublayer, is evaporated. The thickness of the metallized sublayer is greater than 10 nm, preferably greater than 15 nm, particularly greater than 20 nm and / or less than 60 nm, preferably less than 50 nm, particularly less than 40 nm.

[0041] Ideally, the metallized sublayer contributes to the favorable reflection of ultraviolet light irradiated onto the stand-up pouch from the outside.

[0042] In an alternative variant, the functional layer is configured as a barrier sublayer. The barrier sublayer is preferably applied between the sealing layer and the outer layer by plasma-assisted chemical vapor deposition.

[0043] Here, the deposited barrier sublayer can preferably be formed of silicon oxide. Alternatively or additionally, the barrier sublayer can be composed of an amorphous carbon sublayer. In addition, the barrier sublayer can be implemented by a ceramic coating and / or aluminum oxide.

[0044] Preferably, the thickness of the alternative barrier sublayer is 2 nm to 8 nm.

[0045] In another alternative variant of the present invention, the barrier sub-layer can be implemented as an ethylene vinyl alcohol layer and / or a polyvinyl alcohol layer.

[0046] In yet another alternative of the present invention, the barrier sub-layer can be formed in the form of a printed primer sub-layer. This can be implemented, for example, by an ethylene vinyl alcohol sub-layer and / or a polyvinyl alcohol sub-layer and / or a polymer containing carboxyl groups. Here, the barrier sub-layer can either be applied on the inner or outer side of the outer layer or on the outer side of the sealing layer.

[0047] Preferably, the front side has an insertion area for inserting a drinking straw.

[0048] A stand-up pouch for a beverage includes an insertion system for inserting a drinking straw. The drinking straw includes a tubular straw element, and the tubular straw element includes a straw wall, an inlet to be placed in the stand-up pouch, and an outlet to be placed outside the stand-up pouch.

[0049] The straw element can be manufactured by an injection molding method. The cross-section of the straw element can be circular, oval, triangular, or quadrilateral.

[0050] Ideally, the packaging sleeve for the straw element is formed by a thin and transparent polyethylene layer, and the packaging sleeve ensures a hygienic closure of the straw element until the enjoyment of drinking. The ethylene layer is fixed to the stand-up pouch, making it very difficult to remove. The packaging sleeve can be easily opened for removing the straw element. Through the firm connection between the packaging sleeve and the stand-up pouch, effective and common recycling is achieved.

[0051] As a printing method for high-quality packaging, continuous printing methods are mostly applied, such as gravure printing method or flexographic continuous printing method.

[0052] The outer layer has a printed pattern preferably applied by reverse printing. The outer layer is printed for indicating the brand and beverage ingredients and for designing the visual impression of the beverage pouch.

[0053] The method often used for printing the outer layer is flexographic continuous printing. This involves a direct relief printing method, which is also called a roller rotary printing method. A flexible printing plate made of a photopolymer or rubber is used in combination with a low-viscosity printing ink. Here, the raised parts of the printing plate carry the image. The advantages lie in the economy caused by using a large printing width and high printing speed and the availability of cost-effective printing inks. Printing tools, photopolymer printing plates, and / or laser-engraved elastomer sleeves are easily available. Large-scale printing production can be economically well completed by flexographic printing.

[0054] The gas permeability of the film is determined under atmospheric pressure conditions in accordance with DIN EN ISO 2556. Here, a test body formed by the film separates two chambers, one of which contains the test gas at atmospheric pressure, and air is evacuated from the other chamber to an almost vacuum state from a known initial volume. The amount of gas flowing from one chamber through the test body into the other chamber is determined as a function of time by measuring the pressure increase in the second chamber with the aid of a pressure gauge.

[0055] Advantageously, the stand-up pouch has an oxygen permeability of less than 10 cm 3 / m 2 ·day·bar, preferably less than 5 cm 3 / m 2 ·day·bar, especially less than 0.1 cm 3 / m 2 ·day·bar, measured at 23 °C and 0% relative humidity. Thus, the beverage in the stand-up pouch can be stored for a long time without artificial preservatives.

[0056] The water vapor permeability is determined in accordance with DIN 53116 by means of a gravimetric method. A test container filled with a desiccant is closed by a specimen of the bag film and subjected to a defined test environment. The amount of water passing through the specimen is determined by weighing. Here, an amount of water in the range from 1 g / (m 2 ·d) to 200 g / (m 2 ·d) can be detected. The detection limit is also related to the sample characteristics and the sample thickness.

[0057] Ideally, the stand-up pouch has a water vapor permeability of less than 10 g / m 2 in 24 h according to the ASTM D6701-01 standard, preferably less than 5 g / m 2 and especially less than 0.1 g / m 2 . Thus, the hot-filled liquid in the stand-up pouch can be stored for a long time without artificial preservatives and is protected against spoilage for a significant period of time.

[0058] The thickness of the film is measured in accordance with DIN 53370 and stated as an average value. In an advantageous variant of the invention, the front side and / or the back side has a thickness of less than 160 μm, preferably less than 140 μm, especially less than 120 μm, and / or a thickness of more than 80 μm, preferably more than 90 μm, especially more than 100 μm. Thus, the stand-up pouch is particularly thin and thus lightweight, while still having outstanding durability.

[0059] In an advantageous variant, the thickness of the front side and / or the thickness of the rear side is at least 1.1 times, preferably at least 1.2 times, in particular at least 1.3 times, and / or is less than 2.0 times, preferably less than 1.8 times, in particular less than 1.6 times, the thickness of the bottom. Thus, material usage can be minimized.

[0060] In an advantageous variant of the invention, at least one sublayer of the multilayer cast polyethylene layer has a proportion of TiO 2 .

[0061] The filler content can be determined using known measurement methods, such as the ashing method. A sample with a known initial weight is heated to a temperature at which the polymer decomposes thermally but not the filler. For example, 560°C has proven advantageous for this purpose. The sample weight is then remeasured. The difference between the final and initial weights allows the polymer content per square meter to be calculated.

[0062] As an alternative to the ashing method, TGA measurements are possible, in which the weight of the sample is continuously measured while heating. This test method can also clearly distinguish between polymer and filler and allows the polymer content of the film to be determined.

[0063] In an advantageous variant of the invention, at least one sublayer of the multilayer cast polyethylene layer comprises an inorganic filler, wherein the proportion of the filler is greater than 0.5% by weight, preferably greater than 1.0% by weight, in particular greater than 1.5% by weight.

[0064] Ideally, the filler is implemented as titanium dioxide, whereby a white sublayer with advantageous opacity can be achieved.

[0065] In a particularly advantageous variant, the filled sublayer of the sealing layer has an opacity of more than 55%, preferably more than 70%, in particular more than 85% according to DIN 53416. As a result, light incident on the stand-up pouch from the outside is advantageously absorbed, thereby advantageously supporting the shelf life of the beverage in the stand-up pouch.

[0066] In a preferred embodiment, the innermost sublayer of the multilayer cast polyethylene layer that comes into contact with the beverage is pigment-free, in particular titanium dioxide-free, thereby effectively preventing the beverage from coming into contact with pigments or even contamination.

[0067] In an advantageous embodiment of the invention, the sealing layer contains a certain proportion of an antistatic agent. The antistatic agent can be selected from the group consisting of glycerides, fatty acids, tertiary amines, fatty acid amides, hydroxy fatty acid amides, alkali metal sulfonates, polyether-modified polydiorganosiloxanes, polyalkylphenylsiloxanes, and / or mixtures thereof.

[0068] Preferably, the sealing layer contains an antistatic agent in an amount of 0.01% to 2% by weight, preferably 0.1% to 1.5% by weight, and most preferably 0.4% to 1.0% by weight of the layer.

[0069] Since the layers are usually stored in the form of stacks or rolls before being combined and sealed to form a stand-up pouch, migration of the antistatic agent may occur. Therefore, the outer layer can be prophylactically equipped with an antistatic agent.

[0070] A particular challenge lies in the dimensional accuracy of the front and back sides, which are in principle constructed from the same material, in particular from the same web. Here, the later front and back sides are printed onto the web of the outer layer simultaneously and bonded to the functional layer and to the sealing layer. Only polyethylene defined by a special material selection and a special manufacturing method can produce such a dimensionally accurate outer layer that can be printed with very small tolerances. The outer layer is characterized by a particularly small deviation in the thickness per unit area.

[0071] Preferably, the front and back sides form a mirror-symmetrical structure with respect to the different layers. In an alternative variant of the invention, the layers can also be arranged differently.

[0072] In an alternative variant of the invention, the functional layer can in principle also be connected to the outer layer and the sealing layer via thermal lamination.

[0073] The shrinkage or shrinkage rate of plastics is understood to mean the change in the dimensional stability of a test body when tested at temperatures T > TG (amorphous) and T > Ts (partially crystalline), which is caused by the resetting of molecular orientation and the relaxation of internal stresses. Orientation is formed due to the processing technology (extrusion, injection molding or deep drawing), so that the orientation is related to the process parameters of the processing technology. The parameters are the temperature of the tool and the melt, the injection pressure and the holding pressure, the flow path length, and the cooling gradient of the film layer.

[0074] In an advantageous variant of the invention, the front side, back side and bottom of the stand-up pouch have a shrinkage rate of less than 2.5%, preferably less than 2.0%, in particular less than 1.5%. Thereby, the front side, back side and bottom are also dimensionally particularly accurate when implemented as a single-material structure, whereby very precise printing is feasible. This dimensional stability is particularly advantageous during hot filling.

[0075] In an advantageous variant, the stand-up pouch, in particular the outer layer and / or the functional layer, has a barrier to UV light in the wavelength range from 250 nm to 800 nm. Here, the transmittance is less than 5%, preferably less than 3%, in particular less than 1%.

[0076] In summary, it is not easy to meet the sum of the said specifications with a single-material structure. This is achieved by a special combination of these selected individual layers implemented as a single material and a special manufacturing method. However, this can also be achieved when using a single layer including one or more sub-layers made of the same material (such as polyethylene). In addition, the stand-up pouch can also be frozen and can withstand the associated mechanical actions.

[0077] In another variant of the invention, the outer layer has a heat-resistant coating. The coating can be formed, for example, in the form of a sub-layer composed of a mixture of amorphous polyamide and partially crystalline polyamide. Such a coating provides improved gas barrier, especially oxygen barrier, and in a further embodiment, it can be provided with a thin metal sub-layer or metal oxide sub-layer, for example by means of a vacuum deposition method.

[0078] Advantageously, compared with a pure polyethylene outer layer, the heat-resistant coating increases the sealing stability of the outer layer and thus also of the entire stand-up pouch by more than 10 °C, preferably by more than 20 °C, especially by more than 25 °C.

[0079] In a further embodiment, at least 90% by weight, preferably more than 95% by weight, of the outer sub-layer of the outer layer is composed of a mixture of amorphous polyamide and partially crystalline polyamide. The thickness of the outer sub-layer of the outer layer is preferably 2 μm to 4 μm. In this embodiment, the outer sub-layer of the outer layer is particularly advantageous in manufacturing the stand-up pouch because it is significantly less likely to adhere to the sealing jaws through which heat is conducted to the front side, rear side, and bottom of the stand-up pouch to form a sealing line. It should be noted here that the controllable share of polyamide in the total mass of the stand-up pouch has proven to be fully in line with the concept of material recycling.

[0080] Alternatively or additionally, a heat-resistant paint can be applied to the outer layer. Thereby, the outer layer is particularly protected during sealing, whereby the outer layer maintains its shape stability and an attractive appearance.

[0081] The front side, rear side, and bottom of the stand-up pouch are connected by a sealing structure. Here, the rectangular front side and rear side are stacked and a w-shaped folded bottom is placed therebetween, wherein the bottom preferably has punching holes for achieving vertical sealing lines.

[0082] Spatial terms relate to a filled and upright stand-up pouch.

[0083] Preferably, first a horizontal seal line and a seal line with an extension are produced in order to connect the bottom to the front side and the rear side. Here, the seal line with the extension has an overlapping portion with the horizontal seal line, and the overlapping portion preferably depicts a curve with a radius of R44 starting from the center of gravity of the front side and the rear side and then transitions into an inclined seal line that extends up to the upper bottom fold. Advantageously, the vertical seal line is finally implemented, and the vertical seal line also includes the folded bottom in the punched area.

[0084] Ideally, the seal line has a width of 4 mm. Here, the inner radius at the transition from the vertical seal line to the horizontal seal line and / or at the transition from the seal line with the extension to the horizontal or vertical seal line is R1. In addition, the rounded corner at the outside of the stand-up pouch preferably has a radius R4.

[0085] In an improvement of the present invention, the vertical seal line has a width in the range of 4.1 mm to 5 mm.

[0086] In order to ensure an advantageous increase in stability, especially by implementing the single-material structure of the stand-up pouch, a transition structure with an extension is formed between the vertical seal line and the rising seal line.

[0087] The sealed transition structure is characterized in particular by an increased sealing surface, and also imparts reliable standing performance to the stand-up pouch even in a single-material structure, and increases the strength of the seal seam, even under the action of hot filling into the stand-up pouch. For this purpose, the transition structure has a special shape.

[0088] In a particularly advantageous variant of the present invention, the transition structure has a vertical extension that is greater than 0.2%, preferably greater than 0.4%, particularly greater than 0.6% and / or less than 8%, preferably less than 6%, particularly less than 4% compared to the total length of the vertical seal line.

[0089] Ideally, the transition structure has a width relative to the vertical seal line, where the width is greater than 5%, preferably greater than 10%, particularly greater than 15%, and / or the width is less than 40%, preferably less than 35%, particularly less than 30%.

[0090] In a particularly preferred variant of the present invention, the transition structure has a circular or oval or lens or oblong or rectangular or square contour. Here, the transition structure can overlap with the vertical seal line and / or the seal line with the extension, whereby only an additional part of the contour in the seal structure is presented. Despite the change in the mechanical properties of the single-material structure, the transition structure still ensures the typically bulging shape of the stand-up pouch.

[0091] Advantageously, the transition structure has a circle segment with a radius R, which is oriented orthogonally to the circle segment, wherein the radius is greater than R2, preferably greater than R3, in particular greater than R4, and / or smaller than R30, preferably smaller than R25, in particular smaller than R20.

[0092] In this case, the radius of the circle segment can point outward or inward, starting from a top view of the stand-up pouch.

[0093] Preferably, the front side and the back side of the stand-up pouch are connected by a vertical sealing line.

[0094] Preferably, horizontal sealing lines and sealing lines with stretches are used to connect the front or back side of the stand-up pouch to the bottom.

[0095] Ideally, the bottom is connected to the front side and the rear side via vertical sealing lines and / or horizontal sealing lines and / or ascending sealing lines.

[0096] In a particularly advantageous variant of the invention, the vertical sealing line has at least one reinforcing structure for waisting the bag.

[0097] The reinforcement structure is preferably provided in the upper half of the stand-up pouch.

[0098] In a particularly preferred variant of the present invention, the reinforcement structure has a circular or oval or lens or oblong or rectangular or square contour. Here, the transition structure can overlap with the vertical sealing line.

[0099] In an advantageous variant of the invention, the sealed stand-up pouch is filled with a beverage having a temperature exceeding 85° C. Immediately after the filling process, the stand-up pouch is closed by horizontal ultrasonic welding.

[0100] Ideally, in addition to the ultrasonic welding, a horizontal sealing line is also formed to durably close the stand-up pouch.

[0101] According to the present invention, a method for producing a stand-up pouch comprises extruding an outer layer and a sealing layer, bonding the outer layer to the sealing layer, and connecting the front side, rear side, and bottom portion via a sealing structure to form the stand-up pouch. Ideally, the sealing layer is not directly bonded to the outer layer. In an advantageous embodiment of the present invention, a functional sublayer is additionally bonded between the outer layer and the sealing layer. In this case, the sealing layer is thicker than the outer layer.

[0102] According to the present invention, a stand-up pouch is used as a fully recyclable, polyethylene-based, disposable beverage packaging for hot-fill beverages.

[0103] Further advantages and features of the invention emerge from the description of exemplary embodiments with the aid of the drawings and from the drawings themselves. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Here it is shown:

[0105] Figure 1 A perspective view of a stand-up bag is shown.

[0106] Figure 2 A diagram showing a sealing structure,

[0107] Figure 3 A schematic diagram showing the configuration of the front and rear sides,

[0108] Figure 4 A schematic diagram showing the bottom structure. DETAILED DESCRIPTION

[0109] exist Figure 1 , a perspective view of a recyclable stand-up bag 1 for beverages is shown, which has a front side 2, a rear side and a bottom 4. An insertion device 12 is provided on the front side 2, into which a drinking straw 13 is introduced.

[0110] Figure 2 The diagram shows the sealing structure of a stand-up bag 1. For this purpose, the front side 2, the rear side 3 and the bottom 4 of the stand-up bag are connected by a sealing structure 14. For this purpose, the bottom 4 with a W-shaped fold is inserted between the rectangular front side 2 and the rectangular rear side 3.

[0111] A horizontal sealing line 16 and a sealing line with a stretch 17 connect the bottom 4 to the front side 2 and the rear side 3. The sealing line with the stretch 17 overlaps the horizontal sealing line 16 in the middle of the lower portion of the front side 2 and the rear side 3. Starting from the center of gravity of the front side 2 or rear side 3, the sealing line with the stretch 17 has a curve 20 with a radius R44 and then extends in an inclined sealing line 21, which extends to an upper bottom fold 22.

[0112] A vertical sealing line 15 connects the front side 2 to the rear side 3. In the region of the bottom 4, punching holes (not shown in the figures) are provided in the bottom to realize the vertical sealing line 15, whereby the sealing layers 9 of the front side 2 and rear side 3 have contact surfaces for forming a seal.

[0113] The sealing lines 15, 16, and 17 have a width of 4 mm. Here, the inner radius 23 at the transition from the vertical sealing line 15 to the horizontal sealing line and / or at the transition from the sealing line with the stretch 17 to the vertical sealing line 15 or to the horizontal sealing line 16 is R1. Furthermore, the rounded corners 24 on the outside of the stand-up pouch have a radius R4.

[0114] In order to ensure the increased stability that is advantageous, in particular due to the single-material construction of the stand-up pouch 1 , a transition structure 18 is formed between the vertical sealing line 15 and the sealing line with the extension 17 .

[0115] In the illustrated exemplary embodiment, the insertion system 12 consists of a combination of an opening 25 in the form of a semi-circular punching in the front side 2 and a strip 26 sealed via a vertical sealing line 15 between the front side 2 and the rear side 3. Additionally, the strip 26 has a sealing shape 29 that matches the punching.

[0116] Figure 3 Schematic view showing the structure of the front side 2 and the rear side 3. A transparent outer layer 5 is provided on the outer side of the stand-up pouch 1, and a printed pattern 6 is applied to the outer layer in the reverse printing method. The inner side of the stand-up pouch 1 is formed by a sealing layer 9. The outer layer 5 and the sealing layer 9 are respectively connected to a functional layer 8 by means of an adhesive sub-layer 7.

[0117] In the exemplary embodiment, the outer layer 5 consists of MDO PE and has a thickness of 20 μm. The sealing layer 9 is formed by cast-PE and has a thickness of 75 μm. The functional layer 8 consists of metallized and oriented PE and has a thickness of 20 μm, a water vapor permeability of less than 0.1 g / m 2 within 24 h, and an oxygen permeability of less than 0.1 cm 3 / m 2 within 24 h.

[0118] In Figure 4 a schematic view showing the structure of the bottom 4 is shown. The outer layer 10 and the sealing layer 11 are respectively connected to the functional layer 8 by means of an adhesive sub-layer 7. In the exemplary embodiment, the outer layer 10 consists of MDO PE and has a thickness of 20 μm. The sealing layer 11 is formed by cast-PE and has a thickness of 75 μm. The functional layer 8 consists of metallized oriented PE and has a thickness of 20 μm.

[0119] In the embodiments described so far, the outer layer, the sealing layer, and the functional layer have been described essentially as uniform layers (single-material layers) composed of or including sub-layers of PE. However, within the scope of the present invention, embodiments can also be proposed in which at least one of the layers (outer layer, sealing layer, and functional layer) can include more than one material sub-layer. The following embodiments can be provided for each of the layers (outer layer, sealing layer, and functional layer) of the sides 2, 3 (front side and rear side) and the bottom or base 4.

[0120] In one embodiment, it is proposed that one of the layers, such as the outer layer, has one or more sub-layers PE, such as 2 or 3 or 4 sub-layers PE, or comprises the one or more sub-layers PE. In particular, one or more of the sub-layers in the layer may be composed of PE or include PE. In addition, one or more of the sub-layers may include HDPE or LDPE. It may also be proposed that one of the layers, such as the outer layer, has one or more sub-layers including PE, one or more sub-layers including HPDE, and / or one or more sub-layers including LDPE.

[0121] The PE sub-layers (including PE, HDPE, and LDPE) can be co-extruded to manufacture the corresponding layer, which can improve the stability of the corresponding surface (such as the side or bottom surface).

[0122] In addition, it may be proposed to apply a first sub-layer having characteristic properties (such as color or barrier properties with respect to the diffusion of liquids and / or gases such as CO2 or oxygen) on one side of the corresponding layer, such as the outer layer, facing away from and / or towards the internal volume of the container. The sub-layer can be, for example, vapor-deposited or rolled or printed. The sub-layer can include, for example, aluminum and / or TiO2 and / or colored pigments and / or EvOH (ethylene-vinyl alcohol copolymer) or be composed of them.

[0123] Alternatively or additionally, another sub-layer having characteristic properties (such as color or barrier properties with respect to the diffusion of liquids and / or gases such as CO2 or oxygen) can also be provided between one or more sub-layers of the corresponding layer on the back side or front side or bottom. Similar to the sub-layer having characteristic properties already described, the another sub-layer can include aluminum and / or TiO2 and / or colored ink and / or EvOH (ethylene-vinyl alcohol copolymer).

[0124] The first sub-layer and the another sub-layer having characteristic properties, if present, can be designed identically or differently. For example, the first sub-layer can be provided on the side of the outer layer facing away from or towards the internal volume and include EvOH or aluminum, and the another sub-layer can be provided between two adjacent sub-layers (such as an HPDE sub-layer and a PE sub-layer or between two PE sub-layers) and also include EvOH and / or include aluminum and / or TiO2. Alternatively, the first sub-layer can include colored pigments.

[0125] In addition, it may be proposed that one of the layers, such as the outer layer, includes one or more connecting sub-layers. For example, it may be proposed to provide a connecting sub-layer based on PE, for example, between one PE sub-layer in the PE sub-layers (PE, HDPE, LDPE) and the first sub-layer and / or the another sub-layer having characteristic properties, in order to achieve a reliable connection between the corresponding PE sub-layer and the sub-layer having characteristic properties.

[0126] Therefore, in one embodiment, it is proposed that, viewed from the inner volume of the stand-up pouch, one of the layers (especially the outer layer) comprises at least two sublayers of polyethylene or also more sublayers of polyethylene (e.g., three sublayers or four sublayers of polyethylene), wherein at least one of the sublayers, preferably all sublayers, consists of or includes PE, EDPE, HDPE, or LDPE. It can also be proposed that there is a mixture of at least one sublayer consisting of PE, a sublayer consisting of HDPE, and a sublayer consisting of LDPE, or that any number of sublayers consisting of PE, HDPE, and LDPE are present.

[0127] The individual sublayers do not necessarily have to have the same thickness. Thus, the innermost sublayer of an outer layer (as viewed from the inner volume of the container) can, for example, be half the thickness of the immediately following sublayer. Said sublayer can be as thick as the subsequent sublayer or sublayers. For example, the innermost sublayer can have a layer thickness of 1 μm to 5 μm, or 2 μm to 4 μm, or 3 μm, wherein at least one of the outermost sublayers has a thickness of 4 μm to 12 μm, preferably 5 μm to 10 μm, preferably 6 μm.

[0128] The adhesive sublayer can be connected to the outermost sublayer polyethylene, and a sublayer having the characteristic properties described above can be arranged on the adhesive sublayer. The sublayer can, for example, include aluminum or EvOH and be designed to be thicker or thinner than the PE sublayer located below it (for example, 1 μm or 2 μm thinner or thicker than the sublayer located below it).

[0129] In another embodiment, at least one of the layers, in particular the functional layer, can also include a plurality of sublayers composed of materials, which do not necessarily all have to be of the same type, but can be of the same type.

[0130] Therefore, it can be provided that the layer, in particular the functional layer, comprises one or more PE sublayers, wherein the sublayers can be composed of PE, HDPE, or LDPE, or a mixture of sublayers composed of PE, HDPE, or LDPE can also be present. The number of sublayers is not limited. Thus, two, three, four, five, or more sublayers composed of PE and / or LDPE and / or HDPE can be present.

[0131] Furthermore, the layer, in particular the functional layer, may include a metallized sublayer. The metallized sublayer may be arranged, for example, such that the metallized sublayer is arranged on the outermost sublayer of the functional layer facing the outer layer and / or on the outermost sublayer of the functional layer facing the sealing layer and / or on an intermediate sublayer of the functional layer.

[0132] The sublayer having characteristic properties may for example comprise, or consist of, EVOH and / or aluminium and / or titanium dioxide. Additionally or alternatively, the sublayer may for example be a sublayer comprising PE, which sublayer has a metallization made of or comprising aluminium. Additionally or alternatively, a color pigment may also be provided in the sublayer.

[0133] Furthermore, a layer, in particular a functional layer, may comprise one or more sublayers made of polypropylene (PP). Thus, the sublayer polypropylene may for example be provided as the outermost sublayer in the direction of the outer layer and / or in the direction of the sealing layer of the functional layer. Additionally or alternatively, the PP sublayer may also be provided between different sublayers of a layer, in particular a functional layer.

[0134] The individual sublayers of a layer, in particular a functional layer, do not have to be of the same thickness. The sublayers may vary arbitrarily in their layer thickness, it being possible to provide that one or more of the sublayers have a layer thickness that is up to 100% greater than the layer thickness of the sublayer having the smallest layer thickness. For example, one or more sublayers may have a layer thickness of from 1 μm to 5 μm, in particular from 2 μm to 4 μm or 3 μm, and at least one of the sublayers of the layer, in particular the functional layer, may have a layer thickness that is at least twice as great, for example 4 μm, 6 μm, 8 μm or 10 μm or 12 μm. The sublayers may be used to reinforce the layer, thus advantageously influencing the stability of the stand-up pouch.

[0135] The connection between a layer, in particular a functional layer, and the above-described embodiments, in particular the outer layer, may be ensured via a sublayer comprising at least one adhesive and optionally other elements such as color pigments or printing inks.

[0136] In one embodiment, it may for example be provided that, seen from the interior volume of the stand-up pouch, the layer, in particular the functional layer, has a first sublayer made of PE or PP, in particular PP. This may be followed by one or more sublayers made of PE (PE, HDPE, LDPE). Thus, after the sublayer, there may be one sublayer, two sublayers, three sublayers, four sublayers or five sublayers made of PE, preferably three to five sublayers, for example four sublayers. Taking four sublayers as an example, it may be provided that all the sublayers are made of PE or all the sublayers are made of HDPE or all the sublayers are made of LDPE, or comprise PE or HDPE or LDPE. Additionally or alternatively, it may be provided that at least one of the sublayers (for example the outermost sublayer or the innermost sublayer) is made of a different PE type from the remaining sublayers. Thus, it may be provided that the outermost sublayer is made of or comprises HDPE or LDPE or MDPE, while the remaining sublayers are made of or comprise other components, in particular HDPE or LDPE. The corresponding design may also be applied to a greater or smaller number of sublayers made of PE.

[0137] Alternative designs with the PE components alternating along the sublayer run can also be envisaged. Thus, the first sublayer can comprise HDPE or LDPE, the subsequent sublayer can comprise LDPE or HDPE, the subsequent sublayer can comprise HDPE or LDPE, and the immediately subsequent sublayer can comprise HDPE, LDPE or MDPE. Other combinations can also be envisaged here.

[0138] Viewed from the inner cavity of the stand-up pouch, the sublayer coated with the outermost PE sublayer having characteristic properties can have a greater layer thickness than at least one of the sublayers located below it. Thus, the sublayer can have, for example, a layer thickness of from 10 μm to 30 μm or a layer thickness of from 15 μm to 25 μm, in particular a layer thickness of from 18 μm to 22 μm. Thereby, for example, the barrier properties or coloring properties of the sublayer can be reliably achieved.

[0139] In another embodiment, it can be proposed that one of the layers, in particular the sealing layer, consists of or comprises a plurality of sublayers of polyethylene and in particular a mixture of polyethylene with, for example, a metal or an inorganic or organic component.

[0140] In particular, it can be proposed that the sealing layer can comprise two or three or more sublayers based on PE, wherein at least one of the sublayers comprises MDPE and / or LLDPE and comprises an additive (for example 1% or 2% or 5% of the total mass of the sublayer) containing, for example, a metal or an inorganic component, such as titanium dioxide, etc.

[0141] The sublayers of the sealing layer can in particular be designed identically, for example all sublayers are based on MDPE and / or all sublayers are based on LLDPE and / or the sublayers are based on a mixture consisting of LLDPE and MDPE. Mixtures with HDPE and / or LDPE can also be envisaged.

[0142] Similar to the embodiments described so far, it can be proposed that one or more sublayers having characteristic properties are arranged in a layer, in particular in the sealing layer. Thus, it can be proposed that, viewed from the internal volume of the stand-up pouch, a sublayer having characteristic properties, for example a sublayer comprising titanium dioxide or aluminum, is arranged on the innermost sublayer, in particular the PE sublayer, and / or a corresponding sublayer is arranged on the outermost sublayer of a layer, in particular a functional layer, or a corresponding sublayer is arranged between at least two adjacent PE sublayers of the layer of the corresponding sublayer. However, this is not mandatory.

[0143] The layer thicknesses of the individual sublayers of a layer may be identical or different. In particular, it may be provided that one of the sublayers is up to 50% or up to 75% thicker than the thinnest sublayer of the layer. For example, the innermost sublayer may have a layer thickness of 10 μm to 30 μm, in particular 15 μm to 25 μm, and particularly preferably 19 μm, 20 μm, or 21 μm. The subsequent sublayers may, for example, have a layer thickness of between 20 μm and 60 μm, in particular between 30 μm and 40 μm, preferably 32 μm, 33 μm, 34 μm, 35 μm, or 36 μm. The subsequent sublayer may have a layer thickness corresponding to the first sublayer, or may be slightly thicker (e.g., 22 μm instead of 21 μm) or slightly thinner (e.g., 19 μm instead of 20 μm). The layer thicknesses may differ from one another in pairs by up to 20%, by up to 15%, or by up to 10%.

[0144] The values described for the respective layer thicknesses can all be combined with one another.

[0145] The embodiments described so far are independent of whether the corresponding layer is a layer on the back side, front side, or bottom side of the stand-up pouch. Although the layer designs for the sealing layer, functional layer, and outer layer are particularly preferred (see above), the sublayer structure described above can be applied to all layers, and the present invention is not limited in terms of the combination of layers having the above sublayer structure.

[0146] In principle, the embodiment described can be applied to all embodiments of the front side, back side and bottom of the stand-up bag. However, in a preferred embodiment, it can be provided that the material thickness of one of the layers, for example the sealing layer, if it is used as the front side or back side of the stand-up bag, should be slightly thicker (for example up to 5% or up to 10% or up to 20%) than the corresponding layer of the bottom.

[0147] For example, it can be provided that the sealing layer is composed of or includes two or more PE sublayers, as described in the previous embodiments, with a layer thickness of between 70 μm and 85 μm, in particular between 75 μm and 80 μm, in particular 77 μm, 78 μm, or 79 μm, being provided for the side surfaces. This results in high stiffness. For the bottom, a smaller layer thickness can be provided for the same layer, for example, between 70 μm and 80 μm, in particular between 75 μm and 78 μm, and for example, 76 μm or 77 μm. The layer thickness can be set by selecting the layer thickness of the individual sublayers of the layer.

[0148] The described embodiments of the individual layers of the stand-up pouch and of the sublayers provided for these layers can all be combined with one another. In particular, the present invention is not limited to specific layer thicknesses of individual layers in combination with specific layer thicknesses of other layers. Within the meaning of the present invention, the specified layer thicknesses of the layers contribute to the stability and leak-tightness of the stand-up pouch, as well as its recyclability.

[0149] Although all combinations of layer thickness, number of sub-layers, and material composition as described above may be proposed within the scope of the present disclosure, further preferred embodiments will be described below. These embodiments should not be understood as restrictive for the entire invention and also for the feasible combinations of the above-described embodiments.

[0150] As already described, the stand-up pouch includes at least one outer layer 5, 10 and a sealing layer 9, 11, wherein optionally a functional layer 8 may be provided between the outer layer and the sealing layer.

[0151] In one embodiment, it may be proposed that the outer layer is made of PE or at least includes PE in a mass fraction of at least 75%, preferably at least 95%. The outer layer may in particular include oriented PE (OPE), preferably biaxially oriented PE (BOPP) or uniaxially oriented PE (MOPE). Alternatively or additionally, the outer layer may also include high-density PE (HDPE) and / or linear low-density polyethylene (LLDPE) and / or medium-density polyethylene (MDPE). As already described, the outer layer may be implemented as a single sub-layer, but also as a multi-sub-layer (for example, including 2 layers, 3 layers, 4 layers or more layers of PE, corresponding to the material variants just described).

[0152] Regardless of the choice of material (but in combination with any of the mentioned embodiments of PE material), the outer layer may have a layer thickness between 10 μm and 30 μm, preferably between 15 μm and 25 μm, in particular between 18 μm and 24 μm. In particular when using OPE (BOPE or MOPE), the proposed layer thickness can ensure sufficient stability and tear strength during the use of a small amount of material.

[0153] As already described, the sealing layer has a greater layer thickness relative to the outer layer, and the layer thickness is preferably 2 to 4 times the layer thickness of the sealing layer. Thus, in one embodiment, it may be proposed that the sealing layer has a layer thickness of 20 μm to 160 μm, preferably 50 μm to 100 μm, particularly preferably 70 μm to 90 μm (for example, between 73 μm and 85 μm).

[0154] The sealing layer may be entirely made of PE, such as OPE (BOPE and / or MOPE) and implemented as a single sub-layer. However, as already described, it may also be proposed that the sealing layer is composed of multiple sub-layers and may have one of the combinations of sub-layers and materials described above. Here, in particular, the combination of LLDPE and MDPE may be preferred. Thereby, the tear strength of the bag material can be further improved and at the same time it can be ensured that when the sealing layer of the stand-up pouch or generally the multi-layer raw material is sealed, the sealing layer can cause a reliable seal of the stand-up pouch.

[0155] In a particularly preferred embodiment, the melting temperature of the outer layer is greater than the melting temperature of the sealing layer, wherein the melting temperature of the outer layer is greater than 110°C, particularly preferably between 120°C and 220°C, particularly preferably between 130°C and 200°C.

[0156] In contrast, the melting temperature of the sealing layer for initiating the sealing process can be between 80°C and 140°C, particularly preferably between 80°C and 110°C. If the material of the sealing layer is appropriately designed, this can, on the one hand, ensure that the stand-up pouch is sealed without damaging the outer layer. On the other hand, the melting temperature is high enough to enable hot filling of the product. To ensure the sterility of the product and thus a long shelf life, liquids, especially those containing sugar, are typically hot-filled, preferably at temperatures above 60°C and below 90°C. If the melting temperature of the sealing layer of a stand-up pouch for hot-filling products at temperature T1 (particularly between 70°C and 87°C) is set by selecting the material of the sealing layer so that the melting temperature is greater than temperature T1 but less than the melting temperature T2 of the outer layer, a reliable sealing of the product and a long shelf life are thereby ensured.

[0157] As already described, the sealing layer can also be implemented in multiple sublayers. In particular, the sealing layer can be composed of 1 to 12 sublayers, preferably 2 to 10 sublayers or 3 to 9 sublayers (eg coextruded PE) or include sublayers thereof.

[0158] The outer layer and the sealing layer can be bonded to one another (as long as no functional layer is disposed therebetween). The adhesive sublayer can preferably have a layer thickness that is less than the layer thicknesses of the outer layer and the sealing layer. For example, the adhesive sublayer can have a layer thickness of between 2 μm and 8 μm or between 3 μm and 7 μm (including all values therebetween, in particular 3 μm, 5 μm, or 6 μm).

[0159] If a functional layer is additionally provided between the outer layer and the sealing layer, the functional layer can be adhesively bonded not only to the sealing layer but also to the functional layer by means of the adhesive sublayer of the aforementioned embodiment.

[0160] In particular, the functional layer can consist entirely of PE with one or more metal additives (e.g., TiO and / or aluminum and / or aluminum oxide). PE can also be present as oriented PE, such as BOPE or MOPE, or as MDPE, LLDPE, or HDPE. Additives, such as EvOH, can also be provided (in place of or in addition to metal additives).

[0161] Instead of (metallic) additives in the PE material of the functional layer, it can also be provided that the PE material is coated with one or more corresponding additives (either on the surface facing the sealing layer or on the surface facing the functional layer).

[0162] In one embodiment, it can be provided that the functional layer has the same thickness as the outer layer, or the functional layer can have a thickness different from that of the outer layer and be, for example, 0.8 to 1.2 times or 0.9 to 1.1 times the thickness of the outer layer.

[0163] As part of the sealing layer and / or as part of the functional layer, one or more (at least partially) opaque sublayers may also be provided. For example, one or more opaque sublayers may be white. This provides a light barrier that prevents damage to the product.

[0164] While the above embodiments have been described with respect to the outer layer, functional layer, and sealing layer as a whole, it should be understood that the embodiments can be applied to the front and back sides of a stand-up pouch as well as the bottom. It can be provided that the total thickness of the bottom is less than the total thickness of the front and / or back sides. For example, the thickness of the bottom can be at least 75%, at least 85%, or at least 90% to 99% of the total thickness of the front or back sides.

[0165] The total thickness of the material comprising the outer layer, the (optional) functional layer and the sealing layer can preferably be between 80 μm and 150 μm, particularly preferably between 100 μm and 140 μm, and particularly preferably between 110 μm and 135 μm (for example 110 μm, 120 μm or 130 μm), wherein the total thickness is preferably lower when the functional layer is not present.

[0166] The embodiments described herein can be applied to stand-up bags having an internal volume of at least 100 ml, at least 200 ml, or at least 330 ml, or to stand-up bags filled with a liquid volume of 200 ml or 330 ml, respectively. Any other volume is also feasible. In particular, volumes of up to 500 ml, up to 1 liter, or up to 2 liters can be provided.

Claims

1. A recyclable stand-up pouch (1) for beverages Based on polyethylene, Having a front side (2), a rear side (3) and a bottom (4), wherein the front side (2), the rear side (3) and the bottom (4) each have a transparent outer layer (5, 10) and a sealing layer (9, 11), characterized in that, The sealing layer (9, 11) has a greater thickness relative to the outer layer (5, 10).

2. The stand-up pouch according to claim 1, wherein The thickness of the sealing layer (9, 11) is configured to be more than 2.00 times, preferably more than 2.75 times, especially more than 3.50 times that of the outer layer (5, 10).

3. The stand-up pouch according to any one of claims 1 or 2, characterized in that, The thickness of the sealing layer (9, 11) is configured to be 6.0 times or less, preferably 5.0 times or less, especially 4.0 times or less that of the outer layer (5, 10).

4. The stand-up pouch according to any one of claims 1 to 3, wherein the thickness of the sealing layer (9, 11) is configured to be between 2 and 5 times or between 3 and 4 times or between 3.5 and 4 times that of the outer layer (5, 10).

5. The stand-up pouch according to any one of claims 1 to 4, characterized in that, The front side (2) and / or the rear side (3) and / or the bottom (4) have at least one functional layer (8), and the at least one functional layer is disposed between the outer layer (5, 10) and the sealing layer (9, 11), wherein the functional layer (8) has a thickness less than 25 μm, preferably less than 20 μm, especially less than 15 μm and / or has a thickness greater than 6 μm, preferably greater than 9 μm, especially greater than 12 μm.

6. The stand-up pouch according to claim 5, wherein The functional layer (8) has a barrier sub-layer and / or a metallized sub-layer and / or a metal sub-layer and / or at least one MDO PE sub-layer.

7. The stand-up pouch according to claim 5 or 6, characterized in that, The functional layer (8) has a vapor-deposited aluminum sub-layer.

8. The stand-up pouch according to any one of claims 1 to 7, characterized in that, The front side (2) has an insertion area (12) for introducing a drinking straw (13).

9. The stand-up pouch according to any one of claims 1 to 8, characterized in that, The outer layer (5) has a printed pattern (6), and the printed pattern is preferably applied as a reverse printed pattern.

10. The stand-up pouch according to any one of claims 1 to 9, characterized in that, The standing pouch (1) has an oxygen permeability of less than 10 cm 3 / m 2 ·day·bar, preferably less than 5 cm 3 / m 2 ·day·bar, especially less than 0.1 cm 3 / m 2 ·day·bar, measured at 23 °C and 0% relative humidity.

11. The stand-up pouch according to any one of claims 1 to 10, characterized in that, The stand-up pouch (1) has a water vapor permeability of less than 10 g / m 2 , preferably less than 5 g / m 2 , especially less than 0.1 g / m 2 in 24 hours according to the ASTM D6701-01 standard.

12. The stand-up pouch according to any one of claims 1 to 11, characterized in that, The front side (2) and / or the rear side (3) have a thickness less than 160 μm, preferably less than 140 μm, especially less than 120 μm and / or have a thickness greater than 80 μm, preferably greater than 90 μm, especially greater than 100 μm.

13. The stand-up pouch according to any one of claims 1 to 12, characterized in that, The thickness of the front side (2) and / or the thickness of the rear side (3) are configured to be more than 1.1 times, preferably more than 1.2 times, especially more than 1.3 times the thickness of the bottom (4) and / or are 2.0 times or less, preferably 1.8 times or less, especially 1.6 times or less the thickness of the bottom (4).

14. The stand-up pouch according to any one of claims 1 to 13, characterized in that, The outer layer (5, 10) is made of MDOPE, wherein the MDO PE is configured to have a draw ratio greater than 2.0 times, preferably greater than 3.0 times, especially greater than 4.0 times and / or less than 7.0 times, preferably less than 6.5 times, especially less than 6.0 times.

15. The self-standing bag according to any one of claims 1 to 14, characterized in that, The sealing layer (9, 11) is formed by a multi-sub-layer cast polyethylene layer.

16. The stand-up pouch according to any one of claims 1 to 15, characterized in that, The front side (2) and / or the rear side (3) and / or the bottom (4) have a shrinkage rate less than 2.5%, preferably less than 2.0%, especially less than 1.5%.

17. The self-supporting bag according to any one of claims 1 to 16, characterized in that, The outer layer (5, 10) has a heat-resistant coating.

18. A method for manufacturing a stand-up pouch (1), the method having the following steps: - Extruding an outer layer (5, 10) and a sealing layer (9, 11), - Bonding the outer layer (5, 10) to the sealing layer (9, 11), - Welding the front side (2) to the back side (3) and the bottom (4) to form a stand-up pouch (1), characterized in that the sealing layer (9, 11) is formed with a greater thickness relative to the outer layer (5, 10).

19. Use of a stand-up pouch (1) according to any one of claims 1 to 17 as a fully recyclable, single-use beverage packaging for hot filling.

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