Polyethylene-based arrangement

Abstract

The invention relates to a Polyethylene-based arrangement (8) for the storage of grain, silage, warm or wet industrial products, comprising at least one outer layer (1), at least one inner layer (7) and at least a first polyamide barrier layer (3). The arrangement (8) comprises at least a further polyamide barrier layer (5), whereas at least one functional layer (4) is arranged between the first barrier layer (3) and the further barrier layer (5). The polyamide is formed as a copolyamide PA 6 / 6.6 with a melting point according to DIN EN ISO 11357 of less than 180 °C.

Description

[0001] Polyethylene-based arrangement.

[0002] Description

[0003] The invention relates to a polyethylene-based arrangement for the storage of grain, silage, warm or wet industrial products, comprising at least one outer layer, at least one inner layer and at least a first polyamide barrier layer.

[0004] Tubular film ensiling is an efficient, flexible and environmentally friendly technology for preserving and storing all types of animal feed or wet industrial products in a specially developed tubular film. Originally developed for the ensiling of green waste, today a wide variety of substrates can be stored in silage tubes. Silage tubes are also used for composting organic material. Today, for example, pressed pulp as well as maize and grass silage are also stored in silage tubes.

[0005] A typical silage tube comprises at least two layers and is approx. 120 m long and 5 m in diameter. Accordingly, high demands are placed on a silage tube in terms of tensile strength and puncture resistance.

[0006] Special machines are required to fill the silage tubes, which usually first crush the material to be stored and then press it into the tubes. DE 10 2010 046 183 A1 describes such a device.

[0007] Sealing against oxygen is of crucial importance for ensiling. Traditionally, stable polyethylene-based films have been used for silage tubes. However, the use of these conventional films has repeatedly led to the formation of mold due to the penetration of oxygen.

[0008] Conventional films for silage tubes based on polyolefins would have to be very thick to ensure sufficient impermeability to oxygen and would therefore be heavy and relatively expensive to produce. For this reason, films with special barrier arrangements were developed for silage tubes. These barrier arrangements are polymers that have a particularly high impermeability to gases, especially oxygen.

[0009] DE 698 17 012 T2 describes a multi-layer film for agricultural silage products. The film has a layer made of a polyamide that acts as an oxygen barrier. The film product can consist of two or more layers, for example co-extruded layers, of which at least one layer or possibly even several layers consist of an insulating plastic layer. In the case of a multilayer film with at least two insulating layers, these insulating layers may consist of the same plastic material or of different plastic materials, all of which are airtight.

[0010] DE 10 2009 052 948 B4 describes a covering system for silage with an underlay film made of a polyamide and a silage film made of a polyethylene.

[0011] DE 10 2017 107 060 A1 discloses a method for increasing the tear resistance of a multilayer film. The multilayer film has at least one barrier arrangement which comprises a total thickness for reducing gas permeability. According to the invention, the barrier arrangement is divided into at least two layers to increase the tear resistance.

[0012] The European Union aims to reduce the landfilling of plastic waste as part of its "Green Deal". By 2030, 55 % of plastic packaging waste is to be recycled. This poses completely new challenges for the production and construction of silage bags, tubes and films.

[0013] In order to meet the challenges of recycling, the design of packaging must become increasingly sustainable. This can be achieved, for example, by realizing and implementing more mono-material constructions. The challenge here lies in achieving the previously known barrier effect with just one recyclable monomaterial construction of a silage sleeve.

[0014] Furthermore, the silage tube must also be able to achieve the mechanical properties achieved to date. Otherwise, the silage tubes could burst during filling or tear during transportation.

[0015] The task of the present invention is to provide a polyethylene-based arrangement that meets the requirements of the Plastics Pact 2025 and is fully recyclable. The polyethylene-based arrangement should also be suitable for packaging and storing grain, silage, warm or wet industrial products. In addition, the polyethylene-based arrangement should be able to exhibit the mechanical properties achieved to date.

[0016] According to the invention, this task is ensured by a polyethylene-based arrangement, a method and a use according to the subsidiary main claims. Preferred variants can be found in the sub-claims, the description, the embodiment example and the drawing.

[0017] According to the invention, the arrangement comprises at least a further polyamide barrier layer whereas at least one functional layer is arranged between the first barrier layer and the further barrier layer, whereas the polyamide is formed as a copolyamide PA 6 / 6.6 with a melting point according to DIN EN ISO 11357 of less than 180 °C.

[0018] DIN EN ISO 11357 is a standard for the determination of thermal properties of plastics, including melting and softening temperatures, specific heat capacity, thermal conductivity and other thermal transitions. The standard specifies various techniques for thermal analysis, including differential scanning calorimetry (DSC), thermogravimetry (TG), dynamic mechanical analysis (DMA) and other methods. These methods enable the characterization of temperature dependencies of various thermal properties.

[0019] The polyethylene-based arrangement can be designed, for example, as a silage bag, silage tube, silage plane or as a silage tarpaulin.

[0020] Polyamides used for silage films usually have melting temperatures of over 220 °C. Special polyamides, for example, have melting temperatures of 207 °C. However, these temperatures are still too high for the silage films, which preferably consist of a high proportion of polyethylene, to be recycled after their intended use. The polyamide with high melting points leads to low bubble stability and high die temperatures, which have an unfavorable effect on the mechanical properties of the downstream products.

[0021] In a particularly advantageous variant of the invention, the polyamide of the barrier layer has a melting point of less than 179 °C according to DIN EN ISO 11357. This previously unattained low melting point of a polyamide component produces a polyethylene-based arrangement specially for silage tubes that can be excellently recycled in accordance with the task.

[0022] For example, the thickness of the barrier layers is more than 5 pm and less than 20 pm. This means that the barrier layer is particularly thin and saves material, while still having excellent barrier properties.

[0023] For example, in the embodiment with two barrier layers, the film has similar individual thicknesses, with the deviation being a maximum of 20 %, preferably a maximum of 10 %, in particular a maximum of 5 %.

[0024] In one variant of the invention, the barrier layers have the same thickness. In addition, the proportion of the barrier layer is less than 5 % by weight of the polyethylene-based arrangement and therefore fully complies with the European Union's specifications for the recyclability of plastic films.

[0025] In particular, the low melting point of the polyamide in the barrier layers results in a recyclate of the polyethylene-based arrangement which, due to the lower overall melting point, is better suited for all processes that allow the recyclate to be reused in a valuable way.

[0026] For example, polyamide of the barrier layer has a density according to ISO 1183- 1 of more than 1.08 g / cm3, preferably more than 1.10 g / cm3and / or less than 1 .20 g / cm3, preferably less than 1.16 g / cm3.

[0027] In a variant of the invention, the polyamide of the barrier layer has a tensile strength at break of more than 80 MPa, preferably of more than 100 MPa and / or of less than 200 MPa, preferably of less than 160 MPa.

[0028] For example, the polyethylene-based arrangement has a seven-layer structure. In the middle, the functional layer is surrounded by a barrier layer and a further barrier layer.

[0029] According to the invention, the barrier layers of the film are divided. Surprisingly, it was found that splitting the barrier layers significantly improves the mechanical properties of the polyethylene-based arrangement while maintaining high oxygen impermeability without increasing the thickness of the film.

[0030] In a variant of the invention, the tear resistance of the polyethylene-based arrangement is increased by a factor of 1.5, preferably by a factor of 2, in particular by a factor of 2.5. This is of great importance in particular for silage tubes. As a result, polyethylene-based arrangement is provided which, with a high oxygen impermeability and a flexible behavior, simultaneously have a high tear resistance, so that undesired bursting or tearing is prevented and at the same time only a relatively small thickness of the polyethylene-based arrangement is required, so that the silage tube according to the invention is relatively light.

[0031] For example, the functional layer comprises least 60 % by weight of an LLDPE with an MFI of more than 0.8 and least 5 % by weight of an maleic anhydride grafted concentrate grade. At the same time, this ensures enormous tear resistance, while also securing the connection to the two barrier layers.

[0032] In one variant of the invention, the proportion of LLDPE in the functional layer is more than 70 % by weight and less than 90 % by weight.

[0033] For example, the proportion of a maleic anhydride grafted concentrate grade in the functional layer is more than 10 % by weight and less than 20 % by weight.

[0034] For example, the functional layer has a proportion of LLDPE which density according to ISO 1183-1 is more than 0.918 g / cm3and is less than 0.922 g / cm3, and which MFI (at 190 °C at 5 kg) according to ISO 1133-1 is more than 0.9 g / 10 min and is less than 1 .1 g / 10 min.

[0035] For example, the functional layer has a proportion of a maleic anhydride grafted concentrate grade which density according to ISO 1183-1 is more than 0.919 g / cm3and is less than 0.921 g / cm3, and which MFR (at 190 °C at 5 kg) according to ISO 1133-1 is more than 0.1 g / 10 min and is less than 0.5 g / 10 min.

[0036] The flow behavior of polyolefins is described using the melt flow rate respectively the MFI according to ISO 1133-1 , usually at a temperature of 190 °C for polyethylene and 230 °C for polypropylene at a load of 2.16 kg, 5 kg or 21 .6 kg. A higher melt flow index correlates with a lower average molecular weight of the polymer. At the same time, the higher the melt index of a polymer, the lower the melt viscosity, which is advantageous for a high output of the extrusion system. On the other hand, polymers with a high molecular weight, i.e. a low melt index, are advantageous in terms of mechanical stability, in particular tensile strength or toughness.

[0037] In one variant of the invention the intermediate layers are arranged between the first barrier layer and the outer layer and the further barrier layer and the inner layer, whereas intermediate layers comprise least 40 % by weight of an mLLDPE and at least 15 % by weight of an LDPE, whereas MFI of the mLLDPE and of the LDPE is below 0,3.

[0038] The production of LLDPE is initiated by transition metal catalysts, in particular Ziegler or Philips type catalysts. The actual polymerization process can be carried out either in the solution phase or in gas phase reactors. As a rule, octene is the comonomer in the solution phase, while butene and hexene are copolymerized with ethylene in a gas phase reactor. LLDPE has a higher tensile strength and a higher impact and puncture resistance than LDPE. It is very flexible and expands under load. It can be used to produce thinner films that have better resistance to stress cracking. It has good resistance to chemicals. It has good electrical properties. However, it is not as easy to process as LDPE, has a lower gloss and a narrower range for heat sealing.

[0039] In one variant of the invention, the proportion of mLLDPE in the intermediate layer is more than 50 % by weight and less than 70 % by weight.

[0040] For example, the proportion of LDPE in the intermediate layer is more than 10 % by weight and less than 30 % by weight.

[0041] For example, the proportion of a maleic anhydride grafted concentrate grade in the intermediate layer is more than 10 % by weight and less than 20 % by weight. In one variant of the invention, the intermediate layer has a proportion of mLLDPE which density according to ISO 1183-1 is more than 0.918 g / cm3and is less than 0.924 g / cm3, and which MFI (at 190 °C at 5 kg) according to ISO 1133-1 is more than 0.1 g / 10 min and is less than 0.28 g / 10 min.

[0042] For example, the intermediate layer has a proportion of LDPE which density according to ISO 1183-1 is more than 0.919 g / cm3and is less than 0.923 g / cm3, and which Ml (at 190 °C at 5 kg) according to ISO 1133-1 is more than 0.1 g / 10 min and is less than 0.29 g / 10 min.

[0043] In one variant of the invention the outer layer and the inner layer comprises least 50 % by weight of an mLLDPE with a MFI of less than 0.6 and at least 15 % by weight LLDPE with a MFI of more than 0.8.

[0044] By way of example, the proportion of mLLDPE in the outer layer and / or the inner layer is more than 55 % by weight and less than 80 % by weight. The proportion of mLLDPE in the outer layer and / or the inner layer advantageously increases the stability of the silage tube.

[0045] For example, the outer layer and / or the inner layer has a proportion of LLDPE. The proportion of LLDPE greatly increases the tear resistance of the outer layer and / or the inner layer. Exemplarily, the amount of LLDPE in the outer layer and / or the inner layer is more than 15 % by weight and / or less than 35 % by weight.

[0046] In one variant of the invention, the outer and / or the inner layer has a proportion of mLLDPE which density according to ISO 1183-1 is more than 0.920 g / cm3and is less than 0.922 g / cm3, and which MFR (at 190 °C at 5 kg) according to ISO 1133-1 is more than 0.3 g / 10 min and is less than 0.55 g / 10 min. For example, the outer and / or the inner layer has a proportion of LLDPE which density according to ISO 1183-1 is more than 0.918 g / cm3and is less than 0.922 g / cm3, and which Ml (at 190 °C at 5 kg) according to ISO 1133-1 is more than 0.85 g / 10 min and is less than 1 .5 g / 10 min.

[0047] The water vapor permeability of dry or moisture-sensitive goods is determined in accordance with DIN 53116 or ASTM D6701-01 using a gravimetric measurement method. A test container filled with a desiccant is sealed with a sample of foil and exposed to a defined test climate. The amount of water permeating through the sample is determined by weighing. A quantity of water in a range of 1 - 200 g / (m2■ d) can be detected. The detection limit is also dependent on the composition and thickness of the sample.

[0048] In a variant of the invention, the polyethylene-based arrangement has a water vapor permeability of less than 50 g / m2, preferably less than 25 g / m2, in particular less than 10 g / m2in 24 h according to ASTM D6701-01 . This makes the storage of grain, silage, warm or wet industrial products particularly advantageous, whereby the silage material is coated for a particularly long time.

[0049] To fulfill its task, a silage tube must have a specific oxygen impermeability. This is the only way to ensure an appropriate fermentation process during ensiling, e.g. in the silage tube, or impermeability to chemicals in the case of disinfection films.

[0050] For example, the polyethylene-based arrangement has an oxygen permeability of less than 100 cm3 / m2d bar, preferably less than 60 cm3 / m2d bar, in particular less than 30 cm3 / m2d bar at 23°C and 50 % relative humidity in accordance with ASTM D3985.

[0051] The Elmendorf test according to DIN 53128 determines the average force in grams or mN required to tear a sample after the tearing process has been initiated. During the test, one or more layers of the film are torn with a pendulum over a defined distance. The force applied during tearing is measured by the loss of potential energy of the pendulum.

[0052] In one variant of the invention, the polyethylene-based arrangement has a tensile strength in the machine direction according to Elmendorf DIN 53128 of more than 20 — , preferably more than 25 — , in particular more than 30 — . This means that |im |im |im the silage tube is optimally prepared for the challenge during the filling process and effectively prevents the silage tube from traveling.

[0053] The puncture resistance is determined in accordance with JAS P1019, whereby a test sample of the polyethylene-based arrangement is clamped in a sample holder. The clamping device is designed so that the inside diameter is 10 mm. A probe with a rounded tip pierces the test sample at a constant speed. The force and elongation required for piercing are determined.

[0054] For example, the polyethylene-based arrangement has a puncture resistance according to JAS P1019 of more than 15 mJ, preferably more than 20 mJ, in particular more than 25 mJ. As a result, the silage film also withstands the demands of filling the silage tube extremely well.

[0055] The polyethylene-based arrangement has a tear resistance in MD according to ASTM 1922 of more than 300 kN / m, preferably more than 400 kN / m, in particular more than 500 kN / m. This makes the silage hose particularly tear-resistant during the filling process as well as during transport and storage.

[0056] The polyethylene-based arrangement has a tear resistance in CD according to ASTM 1922 of more than 300 kN / m, preferably more than 400 kN / m, in particular more than 500 kN / m The polyethylene-based arrangement has a Spencer puncture Energy according to ASTM3420 of more than 2000 mJ, preferably more than 2350 mJ, in particular more than 2700 mJ. The special structure and the specially selected raw materials produce a film for silage tubes that can withstand the enormous mechanical stresses that occur when filling or plugging the hose.

[0057] The special physical parameters of the silage tube are achieved through the selection and combination of suitable raw materials, whereby the structure of the silage tube in particular plays a decisive role in achieving the properties.

[0058] For example, the silage tube has a seven-layer structure.

[0059] In a further variant, the polyethylene-based arrangement is designed with five layers, whereby, in contrast to the seven-layer variant, the outer and inner layers are each not designed as a double layer.

[0060] A version with nine layers is also conceivable.

[0061] In a variant of the invention, the outer layer has a proportion of a titanium dioxide TiC>2. This is preferably coated TiC>2. Due to the proportion of titanium dioxide, the outer layer is white, whereby an excellent reflection of sunlight can be achieved and thus an excellent protection of the silage material can be realized.

[0062] For example, the titanium dioxide is integrated in a white polybatch. In a variant of the invention, the outer layer has a proportion of white polybatch of more than 5 wt.% and less than 20 wt.%.

[0063] In a further variant of the invention, the intermediate layers also have a proportion of white polybatch with titanium dioxide, the proportion in the intermediate layer being more than 5 % by weight and less than 20 % by weight. For example, the functional layer also has a proportion of white polybatch with titanium dioxide, whereby the proportion in the intermediate layer is more than 5 % by weight and less than 20 % by weight.

[0064] Opacity is the opposite of transparency. It is a measure of opacity or opaqueness and is usually expressed as a percentage. In particular, the opacity of a completely opaque film is 100 % and a completely or fully transparent film has an opacity of 0 %.

[0065] For example, the outer layer respectively the polyethylene-based arrangement has an opacity according to DIN 53416 of more than 45 %, preferably more than 60 %, in particular more than 75 %. In this advantageous way, the high-energy solar radiation can be reflected and thus the contents of the silage hose can be effectively protected.

[0066] In a variant of the invention, the inner layer has a proportion of a black pigment.

[0067] For example, the inner layer also has a proportion of black polybatch, whereby the proportion in the inner layer is more than 5 % by weight and less than 20 % by weight.

[0068] A particularly favorable embodiment of the invention is a relatively thin film which, despite its low thickness, has sufficient tear resistance and simultaneously high oxygen barrier properties.

[0069] It proves to be advantageous if the thickness of the polyethylene-based arrangement is less than 400 pm, preferably less than 350 pm, in particular less than 300 pm and / or more than 50 pm, preferably more than 75 pm, in particular more than 100 pm. ASTM D1922 specifies the procedure for determining the tear resistance, or "tear propagation resistance," of plastic film and thin sheeting using a pendulum-type instrument. In the test, a pre-notched specimen is clamped in the device, and a pendulum is released to tear the sample. The force required to propagate the tear is measured by the energy absorbed by the pendulum. The test is typically performed at room temperature, and multiple specimens are tested to ensure accuracy. The average tear resistance is reported in terms of energy per unit thickness or force.

[0070] For example, the polyamide of the first polyamide barrier layer and the further barrier layer has a tear resistance according to ASTM D1922 of more than 1 .8 N, in particular of more than 1 .9 N, preferably of more than 2.0 N, carried out with a 50 pm PA layer for the testing procedure.

[0071] JAS P-1019 outlines the procedure for measuring the tear strength of paper and paperboard materials. In this test, a pre-notched paper sample is secured in a pendulum-type tear tester. The pendulum is released, and the force required to propagate the tear through the sample is measured. The energy absorbed by the pendulum during tearing is used to calculate the tear strength. The test is typically conducted at standard conditions, and multiple samples are tested to ensure consistency. The results are reported as the average tear strength in mN (millinewtons), which reflects the material's resistance to tearing.

[0072] In a variant of the invention, the polyamide of the first polyamide barrier layer and the further barrier layer has a puncture energy according to JAS P-1019 of more than 32 mJ, preferably of more than 34 mJ, carried out with a 50 pm PA layer for the testing procedure.

[0073] For example, the polyamide of the first polyamide barrier layer and the further barrier layer has a puncture deformation according to JAS P-1019 of more than 9.5 mm, preferably of more than 11 mm, carried out with a 50 pm PA layer for the testing procedure.

[0074] The ISO 307 standard outlines the procedure for determining the viscosity number and limiting viscosity number of polyamide solutions using capillary viscometry. First, a polyamide sample is dissolved in an appropriate solvent, such as sulfuric acid, at a specific concentration. The flow time of both the pure solvent and the polymer solution is then measured using a capillary viscometer, ensuring the temperature is maintained at 25°C. The relative viscosity is calculated by dividing the solution's flow time by the solvent’s flow time. From this, the specific viscosity and viscosity number are derived. The limiting viscosity number is determined by extrapolating the viscosity number to zero concentration, which provides insight into the polymer’s molecular weight.

[0075] In a variant of the invention, the polyamide of the first polyamide barrier layer and the further barrier layer has a relative viscosity according to ISO 307 of more than 3.5, in particular of more than 3.8, preferably of more than 4.0.

[0076] The ASTM E794-95 standard outlines the procedure for determining the melting or crystallization temperature of materials using thermal analysis. A small sample is placed in a thermal analysis device, such as a differential thermal analyzer (DTA) or thermomechanical analyzer (TMA). The sample is heated or cooled at a controlled rate, typically 5°C to 10°C per minute. The temperature is recorded as the material undergoes phase transitions, such as melting or crystallization. The onset of the phase change is identified from the thermal curve, and the corresponding temperature is reported as the melting or crystallization point.

[0077] For example, the polyamide of the first polyamide barrier layer and the further barrier layer has a crystallization temperature according to ASTM E794-95 of less than 145 °C, in particular of less than 140 °C, preferably of less than 130 °C. The copolymerization ratio of polyamide, the polyamide of the first polyamide barrier layer and the further barrier layer, refers to the proportion of different monomers used in the polymerization process to create the copolymer. In the case of polyamide of the barrier layers, this ratio typically indicates the balance between two types of monomers, such as diamines and diacids, or lactams, which form the polyamide chains. The ratio affects the material's properties, such as mechanical strength, flexibility, and thermal resistance. For the polyamide of the barrier layers, this ratio determines its specific characteristics tailored for application of silage tubes.

[0078] In a variant of the invention, the polyamide of the first polyamide barrier layer and the further barrier layer has a copolymerization ratio of more than 10 %, in particular of more than 15 %, preferably of more than 20 %, above the copolymerization ratio of an average polyamide.

[0079] The copolymerization ratio of an average polyamide refers to the ratio of monomers used in the synthesis, typically diamines and dicarboxylic acids. In many cases, a 1 :1 ratio of these monomers is used to achieve a regular structure and balanced mechanical properties. This balanced ratio ensures that repeating units are evenly distributed along the polymer chain, which optimizes the stability and strength of the polyamide. Deviations from the ideal ratio can lead to changes in the material properties, such as flexibility or chemical resistance.

[0080] For example, the polyamide of the first polyamide barrier layer and the further barrier layer comprises a copolymerization ratio of PA 6 to PA 6.6 of more than 85 / 15.

[0081] Only through the special selection and the outstanding design of this new polyamide can a silage hose be achieved that, on the one hand, fulfills the recyclability requirements of the EU and, at the same time, achieves at least the mechanical properties of known silage hoses that cannot be classified as recyclable.

[0082] This provides silage tubes which, with a high oxygen impermeability and a flexible behavior, simultaneously have a high tear resistance, so that undesired bursting or tearing is prevented and at the same time only a relatively low thickness of the multilayer film is required, so that the polyethylene-based arrangement according to the invention is relatively light. In addition, the embodiment of the polyethylenebased arrangement according to the invention realizes for the first time a variant which is also considered recyclable according to the new specifications of the European Union and which also proves itself in the practical implementation of recycling due to the low melting point of the polyamide.

[0083] According to the invention, a polyethylene-based arrangement is produced by a process in which an outer layer of polyethylene, two barrier layers of polyamide, an functional layer, two intermediate layers and an inner layer of polyethylene are produced by coextrusion, whereby the extrusion temperature at the nozzle of the barrier layer is less than 200 °C.

[0084] The extruders for blown film coextrusion are usually arranged in a ring around the blowing ring. The raw material, usually plastic granulate or powder, is fed into the hopper. The hopper ensures that the material is fed evenly into the extruder. The extruder screw is the central element of the extruder and is driven by an electric motor in the extrusion barrel. The screw has a helical shape and rotates to melt and advance the plastic material. The screw is divided into different zones, whereby the temperature is increased zone by zone from the hopper to the nozzle. For this purpose, the extrusion barrel is designed as a heated container with several heated zones to ensure precise control of the temperature along the extruder screw. The nozzle is located at the end of the extrusion cylinder. This is where the molten plastic strand is formed before being fed into the blowing ring. In the blowing ring, the melted plastic strand is blown into a flat tube, which is then inflated into a bubble. The blowing ring is tempered to control the temperature of the melted film. After the bubble is formed, the film is passed through a cooling section where cooling air streams or water sprays are used to lower the temperature and stabilize the film. The drawing device pulls the extruded film away from the bubble and ensures a uniform thickness and width. This process defines the final mechanical properties of the polyethylene-based arrangement. The finished polyethylene-based arrangement is rolled up on a winder.

[0085] In a variant of the invention, the difference between the extruder die temperatures for extrusion of the inner and outer layers and the barrier layer is less than 70 °C.

[0086] The special temperature management and control realizes a polyethylene-based arrangement which is advantageously recyclable due to its properties, in particular its melting temperature and its almost unmixed design.

[0087] According to the invention, the polyethylene-based arrangement is used as recyclable silage tube for storing grain, silage, warm or wet industrial products.

[0088] Further features and advantages of the invention are apparent from the description of examples of embodiments.

[0089] Example 1 :

[0090] Outer embodiment example 1 has the following structure of the individual layers:

[0091] 20 % by volume outer layer

[0092] 17 % by volume intermediate layer

[0093] 10 % by volume barrier layer

[0094] 6 % by volume functional layer

[0095] 10 % by volume barrier layer

[0096] 17 % by volume intermediate layer

[0097] 20 % by volume inner layer

[0098] Table 1 shows a seven-layer polyethylene-based arrangement, with the mechanical parameters of the film listed in the right-hand column.

[0099] Further advantages and features of the invention are apparent from the description of an embodiment example with reference to drawings and from the drawings themselves. In this connection

[0100] Fig. 1 a schematic representation of the polyethylene-based arrangement.

[0101] Fig. 1 shows a polyethylene-based arrangement 8 with seven layers for a silage tube.

[0102] In this embodiment, the outer layer 1 is made of a proportion of mLLDPE, whereas the outer layer 1 comprise 61 % by weight of an mLLDPE with a melting temperature of 113 °C and whereas MFI of the mLLDPE is 0.45. In addition, the outer layer 1 has a proportion of LLDPE, whereas the outer layer 1 comprise 25 % by weight of an LLDPE with a melting temperature of 119 °C and whereas MFI of the LLDPE is 1.0. The outer layer 1 also contains a proportion of white masterbatch, whereas outer layer 1 comprise 7 % by weight of a white Masterbatch and whereas MFI of the white masterbatch is 15.0. Furthermore, the outer layer 1 contains additives and flow aids of 6 % by weight.

[0103] The intermediate layers 2 and 6 are made of a proportion of LDPE, whereas the intermediate layers 2 and 6 comprise 53.5 % by weight of an LDPE with a melting temperature of 116 °C and whereas MFI of the LDPE is 0.27. In addition, the intermediate layers 2 and 6 have a proportion of a further LDPE, whereas the intermediate layers 2 and 6 comprise 20 % by weight of an LDPE and whereas MFI of the LDPE is 0.25. The intermediate layers 2 and 6 also contain a proportion of white masterbatch, whereas the intermediate layers 2 and 6 comprise 12 % by weight of a white Masterbatch and whereas MFI of the white masterbatch is 15.0. The proportion of a maleic anhydride grafted concentrate grade in the intermediate layers 2 and 6 are 10 % by weight, whereas MFI of the maleic anhydride grafted concentrate grade is 0.3. Furthermore, the intermediate layers 2 and 6 contains additives and flow aids of 4 % by weight. The barrier layers 3 and 5 are made of a copolyamide PA 6 / 6.6, whereby the melting point of the copolyamide PA 6 / 6.6 is 179 °C.

[0104] The functional layer 4 is made of a proportion of LLDPE, whereas the functional layer 4 comprise 76.5 % by weight of an LLDPE with a melting temperature of 119 °C and whereas MFI of the LLDPE is 1 .0. The functional layer 4 also contains a proportion of white masterbatch, whereas functional layer 4 comprise 8 % by weight of a white masterbatch and whereas MFI of the white masterbatch is 1 .0. Furthermore, the functional layer 4 contains additives and flow aids of 3.5 % by weight. The proportion of a maleic anhydride grafted concentrate grade in the functional layer 4 is 10 % by weight, whereas MFI of the maleic anhydride grafted concentrate grade is 0.3.

[0105] The inner layer 7 is made of a proportion of mLLDPE, whereas the inner layer 7 comprise 63.5 % by weight of an mLLDPE with a melting temperature of 113 °C and whereas MFI of the mLLDPE is 0.45. In addition, the inner layer 7 has a proportion of LLDPE, whereas the inner layer 7 comprise 25 % by weight of an LLDPE with a melting temperature of 119 °C and whereas MFI of the LLDPE is 1.0. The inner layer 7 also contains a proportion of black masterbatch, whereas inner layer 7 comprise 8 % by weight of a black masterbatch and whereas MFI of the black masterbatch is 15.0. Furthermore, the inner layer 7 contains additives and flow aids of 4 % by weight.

Claims

Polyethylene-based arrangementClaims1 . Polyethylene-based arrangement (8) for the storage of grain, silage, warm or wet industrial products, comprising:- at least one outer layer (1 )- at least one inner layer (7) - at least a first polyamide barrier layer (3), characterized in that the arrangement (8) comprises at least a further polyamide barrier layer (5), whereas at least one functional layer (4) is arranged between the first barrier layer (3) and the further barrier layer (5), whereas the polyamide is formed as a copolyamide PA 6 / 6.6 with a melting point according to DIN EN ISO 11357 of less than 180 °C.

2. Polyethylene-based arrangement according to claim 1 , characterized in that intermediate layers (2, 6) are arranged between the first barrier layer (3) and the outer layer (1 ) and the further barrier layer (5) and the inner layer(7), whereas intermediate layers (2, 6) comprises least 40 % by weight of an mLLDPE and at least 15 % by weight of an LDPE, whereas MFI of the mLLDPE and of the LDPE is below 0.3.

3. Polyethylene-based arrangement according to claim 1 or 2, characterized in that the outer layer (1 ) and the inner layer (7) comprises least 50 % by weight of an mLLDPE with a MFI of less than 0.6 and at least 15 % by weight LLDPE with a MFI of more than 0.8.

4. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the functional layer (4) comprises least 60 % by weight of an LLDPE with a MFI of more than 0.8 and least 5 % by weight of an maleic anhydride grafted concentrate grade.

5. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyethylene-based arrangement (8) has a water vapour permeability of less than 50 g / m2, preferably of less than 25 g / m2, in particular of less than 10 g / m2in 24 h according to ASTM D6701-01.

6. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyethylene-based arrangement (8) has an oxygen permeability of less than 100 cm3 / m2d bar, preferably of less than 60 cm3 / m2d bar, in particular of less than 30 cm3 / m2d bar according to ASTM D3985.

7. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyethylene-based arrangement (8) has a puncture resistance energy according to JAS P1019 of more than 15 mJ, preferably more than 20 mJ, in particular more than 25 mJ.

8. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyethylene-based arrangement (8) has a tear resistance in MD according to ASTM 1922 of more than 300 kN / m, preferably more than 400 kN / m, in particular more than 500 kN / m.

9. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyethylene-based arrangement (8) has a tear resistance in CD according to ASTM 1922 of more than 300 kN / m, preferably more than 400 kN / m, in particular more than 500 kN / m10. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyethylene-based arrangement (8) has a Spencer puncture Energy according to ASTM3420 of more than 2000 mJ, preferably more than 2350 mJ, in particular more than 2700 mJ.

11. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyethylene-based arrangement (8) has a tensile strength in the machine direction and / or cross machine direction according to Elmendorf DIN 53128 of more than 20 — , preferably more than 25 — , in particular more than 30 — .|im |im12. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the outer layer (1 ) has an opacity according to DIN 53416 of more than 45 %, preferably more than 60 %, in particular more than 75 %.

13. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyethylene-based arrangement (8) has a thickness of less than 400 pm, preferably less than 350 pm, in particular less than 300 pm and / or more than 50 pm, preferably more than 80 pm, in particular more than 100 pm.

14. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyamide of the first polyamide barrier layer (3) and the further barrier layer (5) has a tear resistance according to ASTM D1922 of more than 1 .8 N.

15. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyamide of the first polyamide barrier layer (3) and the further barrier layer (5) has a puncture energy according to JAS P-1019 of more than 32 mJ.

16. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyamide of the first polyamide barrier layer (3) and the further barrier layer (5) has a puncture deformation according to JAS P-1019 of more than 9.5 mm.

17. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyamide of the first polyamide barrier layer (3) and the further barrier layer (5) has a copolymerization ratio of more than 10 % above the copolymerization ratio of an average polyamide.

18. Polyethylene-based arrangement according to at least one of the proceeding claims, characterized in that the polyamide of the first polyamide barrier layer (3) and the further barrier layer (5) comprises a copolymerization ratio of PA 6 to PA 6.6 of more than 85 / 15.

19. Process for the manufacture of a polyethylene-based arrangement (8) comprising the following steps: extrusion of an outer layer (1 ) of a polyethylene, - extrusion of a barrier layer (3, 5) of a polyamide, extrusion of an inner layer (7) of a polyethylene, characterized in that the extrusion temperature at the nozzle of the barrier layer (3, 5) is less than 200 °C.

20. Use of a polyethylene-based arrangement (8) according to any one of claims 1 to 13 as recyclable silage tube for the storage of grain, silage, warm or wet industrial products.

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