Recyclable sterile package and related methods

Abstract

The present disclosure relates to the field of packaging and provides for recyclable, aseptic packaging for food and other items, as well as methods of use and production associated therewith.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 533,593, filed August 18, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of packaging and provides recyclable aseptic packaging for food and other articles, as well as manufacturing methods and methods of use thereof. Background Technology

[0003] Typically, single-use packaging containers for liquids (and other) foods are made from packaging laminates based on cardboard or cartons. One common type of container is marketed under the brand name Tetra Brik Aseptic® and is commonly used for aseptic packaging of liquid foods such as milk and juice for long-term storage and sale. The packaging material used in this type of container is typically a laminate consisting of a main layer of paper or cardboard and one or more outer liquid-tight layers comprising thermoplastic materials. To ensure the container is airtight (e.g., for aseptic packaging, milk, or juice packaging), the laminate usually includes at least one additional layer, most commonly aluminum foil. This multi-material laminate structure has been designed to withstand the harsh conditions required to establish and maintain a sterile environment.

[0004] However, the multi-material laminates currently used in packaging have a major drawback: their recycling is often extremely complex and expensive, making them environmentally unsustainable. In particular, the use of cardboard and aluminum has a significant impact on global warming, as obtaining these materials requires substantial amounts of energy and water (and cardboard also contributes to deforestation). Summary of the Invention

[0005] Given the aforementioned shortcomings of current multi-material laminated packaging containers, there is an urgent need for alternative designs, especially those that can achieve efficient recycling without sacrificing structural integrity and / or other critical packaging performance. This disclosure addresses these and other needs by providing a process for manufacturing rigid, shelf-stable aseptic packaging on novel and existing roll-fed aseptic filling machines, wherein the resulting packaging can be subsequently ground, cleaned, dried, and reused to manufacture packaging materials designed to be fed back into roll-fed filling machines. The aforementioned and other advantages of the packaging materials, structures, and methods described in this disclosure will become further clear when combined with the following description and accompanying drawings.

[0006] In a first general aspect, this disclosure provides a multilayer sheet comprising a plurality of layers arranged in the following order: a first rigid layer, a first foam layer, one or more layers of recycled material between the first foam layer and a second foam layer, and a second rigid layer.

[0007] In some aspects, the multilayer sheet further includes an outer layer adjacent to the first rigid layer. In some aspects, the multilayer sheet further includes a third rigid layer adjacent to the second rigid layer. In some aspects, the multilayer sheet further includes an outer layer adjacent to the first and second rigid layers.

[0008] In some cases, the first rigid layer of a multilayer sheet comprises: a) 25% HDPE, 20% CaCO3MB, 50% talc MB, and 5% TiO2MB. As used herein, “MB” refers to “masterbatch”. MB is a solid additive used to color plastics (coloring masterbatch) or to impart other properties to plastics (functional masterbatch).

[0009] In some aspects, the first foam layer of the multilayer sheet comprises: a) 10% LDPE, 10% talc MB, 35% recycled material, and 45% HDPE, optionally, wherein the recycled material comprises recycled packaging (e.g., post-consumer aseptic packaging).

[0010] In some aspects, the one or more layers of recycled material include an adhesive layer.

[0011] In some aspects, each of one or more layers of recycled material comprises: a) recycled material, wherein at least a portion of the recycled material comprises recycled packaging; or b) recycled material, wherein the recycled material comprises recycled packaging. In some aspects, each of one or more layers of recycled material comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 60, 70, 80, 90, or 100% recycled material, or a percentage of recycled material selected from the endpoints of any of the above percentage values.

[0012] In some aspects, the second foam layer comprises: a) 10% LDPE, 10% talc MB, 35% recycled material, and 45% HDPE, optionally wherein the recycled material comprises recycled packaging. In some aspects, the second foam layer comprises: a) 0-20% LDPE, 0-25% talc MB, 10-50% recycled material, 25-55% HDPE, and 0-20% CaCO3, or integer percentages of LDPE, talc MB, recycled material, HDPE, and / or CaCO3 within any of the above ranges.

[0013] In some aspects, the second rigid layer comprises: a) 50% talc MB, 30% HDPE, and 20% CaCO3. In some aspects, the second rigid layer comprises: a) 20-75% talc MB, 10-40% HDPE, and 0-35% CaCO3, or integer percentages of LDPE, recycled materials, HDPE, and / or CaCO3 within any of the above ranges.

[0014] In some respects, the outer layer comprises LDPE.

[0015] In some aspects, the third rigid layer comprises: a) 30% HDPE, 20% CaCO3MB, 50% talc MB, and 5% TiO2MB. In some aspects, the third rigid layer comprises: a) 10-40% HDPE, 0-35% CaCO3MB, 20-75% talc MB, and 2.5-10% TiO2MB, or integer percentages of HDPE, CaCO3MB, and / or TiO2MB within any of the above ranges.

[0016] In some aspects, the thickness of the first rigid layer is 20-60 μm; the thickness of the second rigid layer is 20-60 μm; the thickness of the third rigid layer is 20-60 μm; the thickness of the first foam layer is 60-300 μm; the thickness of the second foam layer is 60-300 μm; the thickness of the recycled material layer is independently selected to be 2-20 μm; and / or the thickness of the outer layer is 10-70 μm.

[0017] In some aspects, the thickness of the first rigid layer is 20-60 μm; the thickness of the second rigid layer is 20-60 μm; the thickness of the first foam layer is 110-220 μm; the thickness of the second foam layer is 110-220 μm; the thickness of the recycled material layer is independently selected to be 2-15 μm; and the thickness of the outer layer is 10-20 μm.

[0018] In some aspects, the first and / or second foam layers of the multilayer sheet comprise microfoam layers prepared by: a) injecting supercritical gas into the layers; or b) chemical foaming achieved by causing large gas releases through the mixing of an endothermic agent in the layers.

[0019] In some aspects, the multilayer sheet of any of the above aspects may be laminated to a second multilayer film, the second multilayer film comprising a laminate, an impact-resistant layer, at least one adhesive layer, a barrier layer and / or at least one packaging seal layer.

[0020] In some aspects, the second multilayer film includes a plurality of layers arranged in the following order: a laminate; an impact-resistant layer; a first adhesive layer; a barrier layer; optionally, a second adhesive layer; a first packaging seal layer; and optionally, a second packaging seal layer.

[0021] In some aspects, the laminate comprises: a) 70% Dow Innate ST50 polyethylene and 25% a small amount of additives. In some aspects, the laminate comprises: a) 50-90% Dow Innate ST50 polyethylene and 10-35% a small amount of additives, or an integer percentage of Dow Innate ST50 polyethylene or a small amount of additives within any of the above ranges.

[0022] In some aspects, the impact-resistant layer comprises: a) 75% Dow Innate ST50 polyethylene and 25% LDPE.

[0023] In some aspects, the first adhesive layer and / or the second adhesive layer each independently comprise: a) 30% Bondyram 5101 (maleic anhydride) and 70% Dow Innate ST50 polyethylene. In some aspects, the first adhesive layer and / or the second adhesive layer each independently comprise: a) 30% Bondyram TL 4108 (maleic anhydride modified polyethylene) and 70% Dow Innate ST50 polyethylene. In some aspects, each independently comprises: a) 10-40% Bondyram 5101 (maleic anhydride) or Bondyram TL 4108 (maleic anhydride modified polyethylene) and 40-90% Dow Innate ST50 polyethylene, or any integer percentage of Bondyram 5101 (maleic anhydride), Bondyram TL 4108 (maleic anhydride modified polyethylene), or Dow Innate ST50 polyethylene within the above ranges.

[0024] In some aspects, the barrier layer comprises ethylene-vinyl alcohol, such as Kuraray F171 EVOH.

[0025] In some aspects, the first and / or second packaging sealing layers each independently comprise: a) 31% Dow Innate ST50 polyethylene, 60% Dow Engage 8770 plastide (or Dow Affinity VP8770G1 plastide), and 9% a small amount of additives. In some aspects, the first and / or second packaging sealing layers each independently comprise: a) 20-40% Dow Innate ST50 polyethylene, 50-70% Dow Engage 8770 plastide (or Dow Affinity VP 8770G1 plastide), and 5-15% a small amount of additives, or integer percentages of Dow Innate ST50 polyethylene, Dow Engage 8770 plastide, Dow Affinity VP 8770G1 plastide, or a small amount of additives within any of the above ranges.

[0026] In some aspects, the thickness of the laminate is 15-80 μm; the thickness of the impact-resistant layer is 15-40 μm; the thickness of the first adhesive layer and the second adhesive layer are each independently selected to be 2-15 μm; the thickness of the barrier layer is 2-15 μm; and / or the thickness of the first packaging sealing layer and the second packaging sealing layer are each independently selected to be 10-25 μm.

[0027] In some aspects, the thickness of the laminate is 69 μm; the thickness of the impact-resistant layer is 15 μm; the thickness of the first adhesive layer and the second adhesive layer are each independently selected to be 3 μm; the thickness of the barrier layer is 3 μm; and the thickness of the first packaging sealing layer and the second packaging sealing layer are each independently selected to be 15 μm.

[0028] In a second aspect, this disclosure provides a method of manufacturing aseptic packaging, comprising: a) providing a multilayer sheet according to any of the above embodiments, wherein the multilayer sheet has a thickness of 200-800 μm (e.g., 200, 300, 400, 500, 600, 700 or 800 μm, or a thickness within the range defined by any pair of the above values), and a nominal flexural stiffness of 20-500 Taper units (e.g., 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480 or 500). (a) Taper units, or quantities within the range defined by any pair of values ​​above); b) Cutting one or more holes through a multilayer sheet; c) Forming a laminated multilayer sheet by laminating the multilayer sheet cut in step b) onto a second multilayer film comprising a laminate layer, an impact-resistant layer, at least one adhesive layer, a barrier layer, and at least one packaging sealing layer, wherein the lamination creates one or more holes covered by the multilayer film; d) Forming creased aseptic packaging material by adding one or more creases to the laminated multilayer sheet; e) Optionally, rolling the pre-creased aseptic packaging material into a roll.

[0029] In some respects, the nominal bending stiffness is measured at 15°.

[0030] In some respects, the multilayer sheet provided in step a) contains at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% recycled polyolefin.

[0031] In some aspects, the method of manufacturing aseptic packaging further includes the following steps: prior to step b), performing a double-sided surface treatment on the multilayer sheet provided in step a) to laterally increase the energy of the surface of the multilayer sheet to at least 35 dynes, while masking the longitudinal overlap sealing area of ​​the surface.

[0032] In some aspects, the method of manufacturing aseptic packaging further includes the steps of printing on at least one side of the multilayer sheet in step a), optionally after surface treatment of both sides of the multilayer film.

[0033] In some aspects, the use of inks resistant to high concentrations of hydrogen peroxide for printing registration marks that are compatible with roll-to-roll filling machines, and the application of a two-component varnish (such as Siegwerk Flexo OPV FSBM7BONH) that is resistant to both high concentrations of hydrogen peroxide and the high temperatures of hot air typically generated by roll-to-roll aseptic filling machines.

[0034] In some aspects, steps b) through d) are performed using a multi-die rotary creasing machine, wherein a first die is configured to cut one or more holes through the multilayer sheet to laminate the barrier film to the non-printing surface of the multilayer sheet, and a second die adds creasing to the laminated multilayer sheet.

[0035] In some aspects, one or more creases added to the laminated multilayer sheet in step d) are configured to fold the laminated multilayer film into a rigid box.

[0036] In a third aspect, this disclosure provides a method for filling aseptic packaging, comprising: a) providing aseptic packaging material with creases as described herein, wherein the aseptic packaging material with creases is rolled into a roll; b) sterilizing the roll by feeding it into a roll-fed aseptic filling machine configured to sterilize the aseptic packaging material with creases by passing the material through a heated bath containing hydrogen peroxide, optionally wherein the temperature of the bath is in the range of 40-80°C and the weight concentration of hydrogen peroxide is 20-50%; c) after sterilization, removing the hydrogen peroxide from the aseptic packaging material with creases by passing the material through a scraper and blowing sterile hot air onto both sides of the sheet; d) folding the aseptic packaging material with creases into a continuous tube and sealing the tube longitudinally to form a continuous liquid-tight tube; e) filling the tube with pasteurized liquid; f) laterally sealing the filled tube.

[0037] In some aspects, step f) is performed using a roll-feed aseptic filling machine with opposing claws, the claws being configured to clamp the filling tube while simultaneously closing and pulling the tube.

[0038] In some aspects, step f) is performed by replacing the claw-sensor sealing system of the roll-feed filling machine with a pulse sealing system, a thermostatic sealing system, or an ultrasonic sealing system. In some aspects, steps d) through f) are performed in a sterile environment.

[0039] Brief description of the attached figures The accompanying drawings mentioned herein illustrate and describe exemplary aspects of this disclosure and are not intended to limit the scope of the invention as defined by the claims.

[0040] Figure 1 This diagram illustrates an exemplary method for manufacturing and filling aseptic packaging, representing one aspect of this disclosure. In particular, it shows a process for producing recyclable aseptic packaging using waste aseptic packaging on a continuous roll-to-roll feeding device.

[0041] Figure 2 This is a schematic diagram illustrating a process for manufacturing aseptic packaging using a hot-melt unit according to an exemplary aspect of this disclosure.

[0042] Figure 3This is a schematic diagram illustrating another process for manufacturing aseptic packaging using ultrasonic processing according to an exemplary aspect of this disclosure.

[0043] Figure 4 A schematic diagram illustrates a general process for manufacturing aseptic packaging according to exemplary aspects of this disclosure. In particular, the diagram illustrates a process for creating an opening in a sealed aseptic package.

[0044] Figure 5 An exemplary method is shown for ensuring the structural integrity of the sealing tube during the sterilization step of the feed tube in an aseptic filling machine. This step is performed before filling begins and involves blowing ultra-high temperature sterile air through the feed tube, wherein the air exits from the bottom of the filling tube, flows back through the empty sealing tube, and is discharged into the sterile chamber.

[0045] Figure 6 This is a perspective view of a multilayer sheet that can be used to manufacture aseptic packaging according to this disclosure. In this case, the multilayer sheet includes a rigid sheet assembly that can be laminated to a barrier film assembly to form aseptic packaging.

[0046] Figure 7 This is a perspective view of a multilayer film that can be used to manufacture aseptic packaging according to this disclosure. In this case, the multilayer sheet includes a nitrogen-injected... Figure 6 The rigid sheet assembly shown in the figure. As illustrated, the first or second foam layer of the rigid film assembly can expand to form microfoams after the injection of a gas (such as N2 or CO2) or the release of a gas by an endothermic agent. The rigid sheet assembly with one or more microfoam layers can be laminated onto a barrier membrane assembly to form aseptic packaging.

[0047] Figure 8 This is a perspective view of a multilayer film that can be used to manufacture aseptic packaging according to this disclosure. In this case, the multilayer film includes an oxygen barrier membrane assembly that can be laminated to a rigid sheet assembly to form aseptic packaging.

[0048] Figure 9 This is a perspective view of a laminated multilayer sheet that can be used to manufacture aseptic packaging according to this disclosure. In this case, the laminated multilayer film comprises... Figure 7 The rigid film assembly shown is laminated to Figure 8 The barrier membrane assembly shown is used to form aseptic packaging. Detailed Implementation

[0049] The following detailed description, taken in conjunction with the accompanying drawings, is intended to illustrate various configurations of this disclosure and is not intended to imply that the concepts described herein can only be implemented through these configurations. The detailed description includes specific details to ensure a full understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be implemented without these specific details.

[0050] Methods for manufacturing aseptic packaging In some aspects, this disclosure provides methods for manufacturing aseptic packaging (e.g., by thermally laminating or ultrasonically welding rigid sheet components to barrier film components).

[0051] Figure 1 A general process for manufacturing and filling aseptic packaging according to exemplary aspects of this disclosure is illustrated. As shown in the figure, this method can be advantageously used to manufacture aseptic packaging from recycled materials. For example, shelf-stable aseptic packaging (290) or other packaging comprising one or more multilayer sheets as described herein can be milled (300) to obtain milled starting material, which is then washed and / or dried (310). The resulting material may also optionally be regranulated (320). In some embodiments, any or all of the above steps can be performed via a polyolefin washing line (330). The washed / dried, optionally regranulated starting material can be collected to provide recycled aseptic box material (340) for subsequent downstream processing (e.g., as a raw material for manufacturing new aseptic packaging).

[0052] In some respects, the recycled aseptic box material (340) may contain at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% of recycled polyolefin, or within any of the above-mentioned pairs of values. The recycled aseptic box material (340) may be fed into a multilayer extrusion line (120).

[0053] In some aspects, the multilayer extrusion line (120) is configured to process recycled aseptic box material (340) or a portion thereof by performing rigid layer extrusion and / or gas-injected multilayer extrusion (110) to produce a multilayer sheet (e.g., comprising a first rigid layer, a first foam layer, one or more layers of recycled material between the first and second foam layers, a second rigid layer, and optionally an outer layer adjacent to the first rigid layer and / or a third rigid layer adjacent to the second rigid layer). The resulting multilayer sheet can be printed (130) on its surface and treated with varnish (140) on at least one side (e.g., by flexographic, gravure, or digital printing press (150)). In some aspects, the multilayer sheet can be used as a rigid component of laminated multilayer sheets, which is described in further detail below.

[0054] Parallel to (or in sequence with) the above, a multilayer extrusion line (120) can be configured to produce a multilayer film by extrusion. This second multilayer film may optionally contain recycled aseptic box material (340), but in some exemplary embodiments, the recycled aseptic box material (340) may be contained only in a rigid sheet. In either case, the multilayer film can be used as a barrier film assembly of a laminated multilayer sheet, as described in further detail below. In some aspects, the multilayer film includes a laminated layer, an impact-resistant layer, at least one adhesive layer (e.g., two adhesive layers), a barrier layer, and / or at least one packaging seal layer. For example, the multilayer film may include multiple layers arranged in the following order: a laminated layer; an impact-resistant layer; a first adhesive layer; a barrier layer; optionally, a second adhesive layer; a first packaging seal layer; optionally, a second packaging seal layer.

[0055] Multilayer sheets and multilayer films can be fed into, for example, a multi-station rotary folding machine (200), configured to cut one or more openings (e.g., holes) (160) in the multilayer sheet and laminate the sheet with the multilayer film (170) to form a composite multilayer sheet. After lamination, the composite multilayer sheet can be folded (180), for example, to allow the composite multilayer sheet to be subsequently folded into the shape of a rigid package. In some aspects, the folded packaging material can optionally be rolled (190) to produce one or more rolls of aseptic packaging material.

[0056] The creased packaging material (optionally rolled) can then be processed using a filling machine (such as a Tetra Pac Tb-8 device or an ESSIBOX aseptic device). As illustrated in this exemplary aspect, the roll of pre-creased packaging material is fed into a roll-feed filling machine configured to unwind the roll (220) and sterilize the unwound pre-creased packaging material by a hydrogen peroxide bath (230) or other means. In some aspects, sterilization can be performed by a heated bath containing hydrogen peroxide, optionally in the range of 40-80°C and with a hydrogen peroxide weight concentration of 10-70%. In particular aspects, the temperature can be 50, 55, 60, 65, 70, 75, or 80°C, or a temperature within the range defined by any pair of the above values. Similarly, the hydrogen peroxide concentration can be at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% (by weight), or a concentration within the range defined by any pair of the above values. In any case, after sterilization, the pre-indented packaging material can be longitudinally sealed (240), filled (e.g., with pasteurized liquid food) (260), and then transversely sealed (250). In a typical embodiment, the sealing and filling steps can be performed in a sterile environment. After sealing, the resulting package can optionally be cut (270) and wing seals can be added (280) to finally obtain shelf-stable aseptic packaging (290) containing liquid food or other contents of the manufacturer's choice.

[0057] like Figure 1 As shown and as stated above, the manufacturing process described herein can be used to recycle shelf-stable aseptic packaging (290) manufactured prior to this process.

[0058] Figure 2-3 This illustration demonstrates the use of a hot-melt apparatus according to various aspects of this disclosure. Figure 2 ) or ultrasonic welding ( Figure 3 An exemplary process for manufacturing aseptic packaging. As demonstrated in these figures, the first and second multilayer films described herein can be manufactured by extrusion and laminated to form a composite multilayer film suitable for aseptic packaging.

[0059] Figure 4 This illustration shows another general method for manufacturing aseptic packaging according to this disclosure, which addresses the above... Figure 1 The processing steps described in the case were summarized.

[0060] Figure 5An exemplary method for ensuring the integrity of the sealing tube during the feed tube sterilization step in an aseptic filling machine is illustrated. This step is performed before filling begins and involves blowing ultra-high temperature sterile air (750) through the feed tube (740) (where air is exhausted from the bottom of the filling tube (790)), which then flows back through the empty sealing tube (770) and into the sterile chamber (830). For the sterility of the sterile area (830), positive pressure must be maintained, meaning the sealing tube cannot be damaged during this step. To prevent ultra-high temperature sterile air from blowing through the holes in the sealing tube, a water ring (820) sprays a water mist onto the surface of the tube outside the sterile chamber (830), thereby preventing the packaging material from melting.

[0061] Multilayer film In some respects, this disclosure provides multilayer films that can be used to manufacture aseptic packaging. Figure 6-9 This is a three-dimensional view of the various multilayer films described herein, including a rigid film assembly for preparing the composite microlayer film for aseptic packaging described herein. Figure 6 In this example, the multilayer film represents an exemplary embodiment of the first multilayer film described in the above-described method of manufacturing aseptic packaging. The first multilayer film includes a first rigid layer (910), a first foam layer (895), one or more layers of recycled material (e.g., layers 870, 880, 890) between the first foam layer and the second foam layer, and a second rigid layer (855). This example also includes outer layers (920) and (840), which are optional components of the first multilayer film.

[0062] It should be understood that, in some respects, rigid sheet assemblies include composite microlayer sheets used in aseptic packaging as described herein. Figure 6 The multilayer membrane may optionally include one or more microfoam layers manufactured by: a) injecting a supercritical gas into the layer, or b) chemical foaming achieved by gas release caused by an endothermic agent mixed in the layer. The gas may be N2, CO2, other harmless and / or inert gases, or mixtures thereof. Figure 7 Indicate Figure 6 A variation of a multilayer sheet, wherein the first and second foam layers have been treated as described above, resulting in the formation of a microfoam layer with an increased thickness than the untreated layers.

[0063] In some aspects, the first rigid layer comprises: 50% talc MB, 25% HDPE, 20% CaCO3 MB, and 5% TiO2 MB. In some aspects, the first foam layer comprises: a) 10% LDPE, 10% talc MB, 35% recycled material, and 45% HDPE, optionally wherein the recycled material includes recycled packaging. In some aspects, one or more layers of recycled material comprise: a) recycled material, wherein at least a portion of the recycled material includes recycled packaging, or b) recycled material, wherein all of the recycled material includes recycled packaging. In some aspects, the second foam layer comprises: a) 10% LDPE, 10% talc MB, 35% recycled material, and 25% HDPE, optionally wherein the recycled material includes recycled packaging. In some aspects, the second rigid layer comprises: a) 50% talc MB, 25% HDPE, 5% TiO2 MB, and 20% CaCO3 MB. In some aspects, the outer layer comprises LDPE. In some cases, the third rigid layer comprises 30% HDPE and 70% LDPE.

[0064] The thickness of each layer in the multilayer sheet can vary in different implementations. For example, the thickness of the first rigid layer can be 10-50 μm; the thickness of the second rigid layer can be 10-50 μm; the thickness of the third rigid layer can be 10-50 μm; the thickness of the first foam layer can be 50-200 μm; the thickness of the second foam layer can be 50-200 μm; the thickness of one or more recycled material layers can be independently selected as 5-25 μm; and / or the thickness of the outer layer can be 10-40 μm.

[0065] Figure 8 A barrier film assembly for manufacturing the composite microlayer film of the aseptic packaging described herein is shown. In this example, the multilayer film represents an exemplary embodiment of the multilayer film in the method of manufacturing aseptic packaging described above. The multilayer film includes a laminate layer (800), an impact-resistant layer (790), at least one adhesive layer (760, 780), a barrier layer (770, in this example, an EVOH barrier layer), and / or at least one packaging sealing layer. In this case, an optional packaging sealing layer (740, 750) is also shown.

[0066] In some aspects, the laminate comprises 70% Dow Innate ST-50 polyethylene and 25% trace amounts of additives. In some aspects, the impact-resistant layer comprises: a) 75% Dow Innate ST-50 polyethylene and 25% LDPE. In some aspects, the first adhesive layer and / or the second adhesive layer each independently comprises: a) 30% Bondyram 5101 (maleic anhydride) or Bondyram TL 4108 (maleic anhydride modified polyethylene) and 70% Dow Innate ST-50. In some aspects, the barrier layer comprises a) EVOH. In some aspects, the first packaging seal layer and / or the second packaging seal layer each independently comprises: a) 31% Dow Innate ST-50 polyethylene, 60% Dow Affinity VP 8770 plastomer (or Dow Affinity VP8770G1 plastomer), and 9% trace amounts of additives.

[0067] The thickness of each layer in the multilayer film can vary in different embodiments. For example, the thickness of the laminate can be 10-30 μm; the thickness of the impact-resistant layer can be 15-30 μm; the thickness of the first adhesive layer and the second adhesive layer can each be independently selected as 2-10 μm; the thickness of the barrier layer can be 2-10 μm; and / or the thickness of the second packaging sealing layer and the second packaging sealing layer can each be independently selected as 10-30 μm.

[0068] Any of the multilayer rigid sheets and multilayer films described herein can be laminated together to prepare sterile packaging with the properties required for a given application using the above-described method for manufacturing sterile packaging.

[0069] Methods of using aseptic packaging In some aspects, this disclosure provides methods for using aseptic packaging (e.g., for containing pasteurized liquid foods). It is also contemplated that aseptic packaging, comprising a multilayer sheet and one or more multilayer films, manufactured according to the methods described herein, can be used to contain any desired contents.

[0070] In some respects, the aseptic packaging described herein can be used to store dry, liquid, or semi-liquid foods. Exemplary foods that can be stored include, for example, dairy products, and non-limiting examples of the foods covered include beverages based on milk, soy, rice, and seeds, fruit juices, sweet fruit juices, carbonated beverages, energy drinks, isotonic beverages, coffee / tea drinks, coconut water, tea drinks, wine, broth, jalapenos, tomatoes, sauces (such as pasta sauce), beans, olive oil, etc.

[0071] In some respects, the packaging described herein can also be used for storing ready-to-eat prepared foods (MREs) requiring a long shelf life when refrigerated. This packaging material is suitable for this application scenario as the most commonly used modified atmosphere packaging (“MAP”), where the air inside the packaging is evacuated and inert gases such as nitrogen (N2), carbon dioxide (CO2), or carbon monoxide (CO) are injected into the food packaging. The barrier properties of the film allow the gas concentration in the MAP packaging to be maintained around the food for an extended period. Because the material is easy to indent, cut, and seal, it can be shaped into… Figure 9 The box shape shown. The same multi-die rotary press (200) is used, in which one die station is configured to cut large holes (160) in a rigid multilayer sheet and laminate the rigid sheet to a multilayer barrier film (170) to form a composite multilayer sheet; it is then crimped (180), which allows the composite multilayer sheet to be subsequently folded into the shape of a rigid package.

[0072] Sheets can be folded and sealed, and then cut to a specified length at the third mold station, or cut into blanks for folding and sealing in subsequent processes.

[0073] Example Example #1: Three-layer foam sheet, seven-layer UHT film Example 1: Three-layer foam board, seven-layer ultra-high temperature sterilization film Post-consumer packaging cartons produced by Essibox machines are shipped to a washing / recycling line in Tocincipa, Colombia. The cartons are emptied before arrival. The first stage of processing involves passing the cartons through a metal detector and then feeding them into a twin-shaft shredder, which shreds them into flakes with an average width of 10 mm. The shredder then feeds the flakes into a heated lye bath containing a single-spiral agitator designed to thoroughly remove any residue from the material's surface. After soaking in the lye bath for 12 minutes, the granular flakes are fed into a stirred rinsing tank designed to remove lye from the material's surface, where they remain for up to 12 minutes. Finally, they are fed into an 8-meter-long water tank equipped with a series of paddle agitators to remove any remaining material from the surface. All flakes remain on the surface of the water bath for approximately 8 meters during the 20-minute transport. After the washing bath, the flakes are fed into a centrifugal dryer, where the central drum rotates at 3600 rpm to remove all surface liquid. The sheet then enters a corrugated chamber called a "label remover," which blows hot air counter-currently through the sheet. The lighter "label" material is carried away by the hot air, while the heavier sheet is collected into a large cardboard box. Once a large cardboard box is full, the sheet is fed into a granulation extruder, where the molten sheet undergoes vacuum and atmospheric pressure degassing to remove any residual moisture from the polymer itself. Finally, the sheet is granulated to produce granules (solid only) identical to the initial aseptic cardboard box composition. During this re-granulation stage, all injected nitrogen is vented.

[0074] Solid granules are then added to the "B" extruder at a ratio of 20% by weight. The extrusion line operates identically to when using 100% new raw materials. (It is anticipated that omitting the granulation stage and directly feeding the flake material into the extruder will also yield no change). Since the "B" extruder accounts for 54% of the final product (184 gsm out of 338 gsm), the 20% recycled cardboard in the "B" layer represents 10.9% of the finished cardboard boxes made from old, recycled, aseptic cardboard.

[0075] In the rigid extrusion process, a blow-up ratio of 3.2 is used to produce a tube with a diameter of 1008 mm. This tube is then pressed into a 1580 mm wide "laid-out" sheet and cut on both sides to create two separate 1.5-meter wide webs. Edge scraps are collected and ground for reuse as recycled material for new extruded sheets. Each web undergoes a corona treatment to increase the surface energy of the printed surface to a minimum of 40 dynes before being wound using a surface winding machine. No masking treatment is performed in the corona treatment unit, thus the entire printed surface is exposed to the surface treatment.

[0076] The virgin HDPE used was SABIC B5429, with a 1% secant modulus of 1050 MPa (ASTM D638). Although the 2% secant modulus is not listed in SABIC's technical documentation, it is estimated to be 850 MPa for SABIC 5429, very close to Dow Chemical's 880 MPa, and 40% lower than Dow Chemical's Elite AT6900. After nitrogen injection, the outer layer remained very smooth, with Sheffield units less than 35 and minimal expansion. Before nitrogen injection, the spacing between the two rigid layers was 164 micrometers, resulting in a normalized Taber stiffness of 23 Taber units. After injecting 0.095% nitrogen, the spacing between the rigid layers decreased to 310 micrometers, resulting in an I-beam stiffness effect and increasing the Taber stiffness to 46. The increase in expansion stiffness is limited by the lower 2% secant modulus of the selected HDPE grade, but its advantage is a very smooth surface, making it ideal for printing. Another factor required for printing and laminating to polyolefins (HDPE, LDPE, LLDPE, PP) is to increase their surface energy from its natural state (approximately 30 dynes) to a transverse energy of over 38 dynes. This is typically achieved using a corona treatment machine on the extrusion line. In this example, the input corona treatment machine is set to 38% of its maximum power and is able to increase the surface energy to greater than 38 dynes.

[0077] The sheet was printed with an image of cows and a farm, and coated with a two-component varnish to protect the roll during the aseptic machine sterilization stage. It was anticipated that the more stable the HDPE-based sheet prepared at this stage, the smoother the machine start-up and the less prone it was to deformation during longitudinal sealing. The varnish used was a two-component system, product number FSBM7BONH (10-619728-8), manufactured by SIEGWERK USA in Des Moines, Iowa. As expected, the image quality was excellent due to the Sheffield value being below 35. After printing, the roll was cut to a finished width of 355 mm to allow for a 25 mm trim allowance per side during the creasing stage. The roll was then fed into a Comco creasing machine, where a 164-tooth solid creasing die was used to creasing the roll at a speed of 8 m / min, with an average creasing depth of 9 mils, and all creasing segments having a 70° cone angle and a 2° radius.

[0078] After crimping, the crimped roll was fed into the Essibox machine, where we encountered problems maintaining a longitudinal seal at the maximum permissible hot air temperature of 340°C. The success rate of longitudinal sealing of the tubing was less than 50%, and the pattern display on the sealing area showed distortion during sealing. Although the melting temperature of the 16.9 gsm polymer in the sealing area was below 100°C, significant adhesion difficulties still existed at the overlap area between the sealing and printed surfaces of the sheet. After investigating the cause of the sealing difficulties, it was found that the surface energy of the overlapping area of ​​the printed surface played an important role in the initiation of the seal. (770) The surface energy measured was >38 dynes. Prior to this discovery, the research team had not tracked the relationship between the lateral surface energy of the overlapping area of ​​the printed surface and the hot air temperature required for longitudinal sealing. Subsequently, the research team measured samples 1-5 and found a direct correlation between the surface energy of the overlapping area and the hot air temperature required for sealing: the higher the dyne value of the sealing area, the higher the hot air temperature setting.

[0079] If the roll material deforms during machine downtime, the sterile environment of the sterile room must be destroyed to repair the damage, and then the entire filling machine (including the filling tube) must be resterilized, which will consume a lot of time and material costs.

[0080] After applying a two-component varnish to the printed surface of the HDPE roll, a significant reduction in deformation was observed in the same sterilization cycle (chamber 330°C, filling tube 360°C). Furthermore, no issues were observed with the roll material at the tube transition area when the production line was restarted after the sterilization step. The sealed tube was sprayed with water outside the sterile chamber 5. Applying a high-temperature resistant varnish to the printed layer is likely a crucial step in the entire process, as its primary function is to protect the roll material from deformation during production line downtime.

[0081] In this example, despite a longitudinal seal failure rate exceeding 50%, sufficient sealed cartons were produced at standard production rates to repeatedly conduct free-fall drop tests on loaded containers according to standard D 585 (ASTM # D5276) and to accept the fiberboard containers. A "four-drop cycle test method" was used (drop test at the corner, the shortest side radiating from that corner, and the longest side radiating from that corner), with selected height increments of 150 mm (approximately 6 inches). The initial height used was 500 mm. All four samples remained intact at the initial height; with a seven-fold increase in height, the first failure was recorded at a height of 1550 mm (3 out of 4 passed), where the failure was due to an overlap in the transverse seal.

[0082]

[0083]

[0084] Example 2: Nine-layer foam sheet and seven-layer laminated film Table 2 lists the data for Examples 2 and 3. The rigid sheet in Example 2 was produced on a 9-layer production line 27 located in Washington Courthouse, Ohio. A 400 mm diameter die was modified with a convergence angle, resulting in a final clearance of less than 0.90 mm. The sheet comprised two foam layers (“C” and “G”), with a nitrogen concentration set such that increasing the nitrogen concentration to 0.135% would cause both layers to expand 2.25 times (from 84 microns to 200 microns). No oxygen barrier material was used in the rigid sheet; layers D, E, and F contained 100% recycled cardboard material, and foam layers C and G each contained 20% recycled cardboard material.

[0085] A 760 mm diameter tubular material was formed using a blow-up ratio of 1.9, which was then pressed into a 1190 mm wide sheet. This sheet was then cut on both sides to create two separate 1.1-meter wide rolls. Edge scraps were collected and ground for reuse as recycled material for new extruded sheets. Each roll underwent a corona treatment to increase the surface energy of the printed side to a minimum of 40 dynes, but the two 28 mm wide zones of the corona treatment were rotated 90° relative to the sheet surface to intentionally avoid activating the surface energy of the overlapping areas. The two rolls were then wound using a surface winding machine. The laminated surface of the rigid sheet was left untreated, with the entire laminated surface exposed to the surface treatment; otherwise, "stringing" would occur.

[0086] The total percentage of recycled cardboard in the rigid sheet was 13.7% by weight, decreasing to 10.9% after lamination onto a 69-micron sterile film. The HDPE used was Braskem Grade HDB0355, with a 1% secant modulus of 1250 MPa (ASTM D638). Layers “B” and “I” are considered the outer rigid layers. Before nitrogen injection, the spacing between the two rigid layers was 203 microns, resulting in a Taber stiffness of 23. After nitrogen injection, the spacing between the two rigid layers increased to 435 microns, creating an I-beam stiffness effect that increased the Taber stiffness to 76. In this sample, the expansion rate of the foam layer increased to 2.38 times the solid thickness, but the surface smoothness improved significantly as the Sheffield smoothness value of the outer layer decreased to less than 25. The sheet was printed and cut to a finished width of 355 mm and sent to a multi-die station for lamination onto the UHT film and final creasing.

[0087] Rigid sheets produced on a 9-layer production line are then laminated onto a 69-micron-thick UHT film specifically designed for the oxygen and sunlight barriers required for stable shelf-life storage of UHT pasteurized milk. This film contains 3 microns of EVOH (from Kuraray's F171 grade) surrounded by a 3-micron-thick adhesive layer. The final sheet of Sample 2 provides oxygen barrier properties through a 69-micron-thick laminate containing 16.9 g / m² of sealant with a melting temperature below 100°C. The oxygen barrier performance of the final product is suitable for aseptic applications (below 5 cc / m²·d); its sealing performance makes a reliable longitudinal seal impossible.

[0088] Two improvements were made to the ESSIBOX filling machine prior to filling: 1. Lower the hot air bar by about 2.5 inches, so that it is within 1 / 2 inch of the longitudinal pressure seal.

[0089] 2. Install a constant temperature single-sided control system to replace the induction heating clip.

[0090] The aseptic sheet performed excellently on the roll-feed filling machine, exhibiting no deformation during sterilization (due to water spraying outside the aseptic zone), maintaining a good seal, and allowing the longitudinal hot air temperature to drop to 285°C during production, the same set temperature as the liquid cardboard product. After the carton edges were folded, they were exposed to the same hot air temperature (480°C) as the cardboard material, and the top of the folded edges remained adhered to the carton surface without any issues, while the bottom remained tucked under the packaging.

[0091] Approximately 50 samples were specifically reserved for evaluating the drop test height of the filling boxes. The four-corner drop test was conducted 24 hours after filling, and the first failure occurred at a height of 1.8 meters.

[0092] Example 3: Nine-layer sheet (without composite film) Example #3: 9-layer sheet, without lamination: Data for this embodiment is shown in Table 2. The rigid sheet in Example 3 was produced on a 9-layer production line 27 located in Washington Courthouse, Ohio. A 400 mm diameter die was modified with a convergence angle, resulting in a final clearance of less than 0.90 mm. The sheet comprises two foam layers (“C” and “G”), with a nitrogen concentration set to expand the two foam layers 2.50 times (from 81 microns to 203 microns) by increasing the nitrogen concentration to 0.150%. Layer E uses an oxygen-barrier material (EVOH, Kuraray F171 grade). Layers D and F use an adhesive layer consisting of 30% maleic anhydride (Bonddyram TL 4108) and 70% Dow Chemical Engage st50 polyethylene. Layers C and G each contain 20% recycled cardboard material, bringing the total recycled cardboard content of the structure to 10.9%. Layer “I” consists of 40% sealing grade material Dow Engage st50 polyethylene and 60% Dow Innate st50 polyethylene.

[0093] A tube with a diameter of 760 mm was formed using a blow-up ratio of 1.9. This tube was then pressed into a flat sheet 1190 mm wide and slit on both sides to form two separate 1.1-meter wide rolls. Edge scraps were collected and ground for reuse as recycled material for new extruded sheets. Only the printed side of each roll was subjected to a corona treatment to increase the surface energy of the printed side to a minimum of 40 dynes. However, the two 28 mm wide zones of the corona treatment were rotated 90° relative to the sheet surface to intentionally avoid activating the surface energy of the overlapping areas. Since the sheets did not require lamination, the inner surfaces were not exposed to the surface treatment. The two rolls were then wound using a surface winding machine.

[0094] The total amount of recycled cardboard in the rigid sheet was 10.1% by weight. The HDPE used was Braskem HDB0355 grade, with a 1% secant modulus of 1250 MPa (ASTM D638). Layers “B” and “H” are considered the outer rigid layers. Before nitrogen injection, these two rigid layers were spaced 171 micrometers apart, resulting in a Taber stiffness of 17. After nitrogen injection, the two rigid layers were spaced 415 micrometers apart, achieving an I-beam stiffness effect in the structure, increasing the Taber stiffness to 68. For this sample, the expansion ratio of the foam layer increased by 2.5 times compared to the solid thickness, but the surface smoothness was significantly improved, as the Sheffield smoothness value of the outer layer increased to below 25. The sheet was printed and cut to a finished width of 355 mm and sent to a multi-mold laminator for lamination onto a UHT film and final creasing. The final sheet of Sample 2 provides oxygen barrier through 3-micron EVOH in the "E" layer, with the sealant (Dow Affinity 8770G1 plastide) located in the "I" layer, weighing a total of 16.2 g / m². The sealant's melting temperature is below 100°C. The oxygen barrier of the final product is suitable for aseptic applications (below 5 cc / m²). 2 • (days); its sealing performance makes it impossible to produce a reliable longitudinal seal.

[0095] Two improvements were made to the ESSIBOX filling machine prior to filling: 1. Lower the hot air bar by about 2.5 inches, so that it is within 1 / 2 inch of the longitudinal pressure seal.

[0096] 2. Install a constant temperature single-sided control system to replace the induction heating clip.

[0097] The aseptic sheet performed excellently on roll-fed filling machines, exhibiting no deformation during sterilization (due to water spraying outside the aseptic zone), maintaining a good seal, and allowing the longitudinal hot air temperature to be reduced to 285°C during production, the same set temperature as for liquid cardboard products. Folding the carton edges and exposing them to the same hot air temperature (480°C) as the cardboard material, the top of the folded edges remained adhered to the carton surface without any issues, and the bottom was tucked under the packaging.

[0098] Approximately 50 samples were specifically reserved for evaluating the drop test height of the filling boxes. The four-corner drop test was conducted 24 hours after filling, and the first failure occurred at a height of 1.65 meters.

[0099] Example #4: 9-layer foam board and 7-layer laminate: Data for this embodiment is provided in Table 3. The rigid sheet in this embodiment was produced on a 9-layer production line 27 located in Washington Courthouse, Ohio. A 400 mm diameter die was modified with a convergence angle, resulting in a final clearance of less than 0.90 mm. The sheet comprises two foam layers (“C” and “G”), wherein the nitrogen concentration is set to expand the two foam layers by 2.40 times (from 90 micrometers to 216 micrometers) by increasing the nitrogen concentration to 0.155%. No oxygen barrier material is used in the rigid sheet; layers D, E, and F contain 100% recycled cardboard material, while foam layers C and G each contain 35% recycled cardboard material.

[0100] The main difference between this embodiment and Examples 1-3 is the use of HDPE-based talc in the first and second rigid molding layers of B and H, and a significant reduction in the amount of CaCO3. It was found that the higher concentration of talc in the rigid layer acts as an excellent foaming nucleating agent, and the foamed layer was able to withstand significantly higher waste cardboard loads compared to samples 1, 2, and 3 with more CaCO3. Furthermore, the presence of the talc-based nucleating agent in the reinforcing layers of B and H also increased the Taber stiffness to 115 (from 76 in Examples 2 and 3).

[0101] Using a blow-up ratio of 1.9, a tube with a diameter of 760 mm was produced, which was then pressed into a flat sheet 1190 mm wide. This sheet was then cut on both sides to form two separate 1.1-meter wide rolls. Edge scraps were collected and ground for reuse as recycled material for new extruded sheets. Each roll underwent a corona treatment to increase the surface energy of both the printed and inner surfaces to a minimum of 40 dynes. Only on the printed surface, two 28 mm wide zones of the corona treatment were rotated 9° relative to the sheet surface to intentionally avoid activating the surface energy of the overlapping areas. Both rolls were wound using a surface winding machine. The laminated surface of the rigid sheet was not treated with any barrier treatment; the entire laminated surface was exposed to the surface treatment, and without treatment, a "stringing" effect would occur.

[0102] The total amount of recycled cardboard in the rigid sheet was 26.7% by weight, which decreased to 23.1% after lamination with a 69-micron sterile film. The HDPE used was Braskem HDB0355 grade, with a 1% secant modulus of 1250 MPa (ASTM D638). Layers “B” and “I” were considered the outer rigid layers. Before nitrogen injection, the two rigid layers were spaced 207 microns apart, resulting in a Taber stiffness of 23. After nitrogen injection, the two rigid layers were spaced 435 microns apart, creating an I-beam stiffness effect that increased the Taber stiffness to 118. For this sample, the expansion rate of the foam layer increased to 2.40 times the solid thickness, but the surface smoothness remained excellent, with a Sheffield smoothness value of less than 25 Sheffield units. The sheet was printed and cut to a finished width of 355 mm and sent to a multi-die station for lamination onto the UHT film and final creasing.

[0103] Rigid sheets prepared on a 9-layer production line were then laminated onto a 69-micron UHT membrane specifically designed for oxygen and sunlight barrier requirements in the shelf-stable storage of UHT pasteurized milk. This membrane contained 3 microns of EVOH (from Kuraray's F171 grade) surrounded by a 3-micron adhesive layer. The final sheet of Sample 4 provided oxygen barrier properties through a 69-micron-thick laminate containing 16.9 g / m² of sealant with a melting temperature below 100°C. The final product's oxygen barrier performance was suitable for aseptic applications (less than 2 cc / m²·day); its sealing performance enabled reliable longitudinal sealing.

[0104] Two improvements were made to the ESSIBOX filling machine prior to filling: 1. Lower the hot air bar by about 2.5 inches so that it is within 1 / 2 inch of the longitudinal pressure seal.

[0105] 2. Install a constant temperature single-sided control system to replace the induction heating gripper.

[0106] The aseptic sheet performed excellently on roll-fed filling machines, exhibiting no deformation during sterilization (due to water spraying outside the aseptic zone), maintaining a good seal, and allowing the longitudinal hot air temperature to be reduced to 285°C during production, the same set temperature as for liquid cardboard products. Folding the carton edges and exposing them to the same hot air temperature (480°C) as the cardboard material, the top of the folded edges remained adhered to the carton surface without any issues, and the bottom was tucked under the packaging.

[0107] For the thermostatic gripper, the machine seal and the control system, manufactured by TOSS MachineComponents in Nazareth, Pennsylvania, were modified. The gripper temperature is set at 235°C, and the seal is heated over a 650-millisecond cycle.

[0108] Approximately 50 samples were specifically reserved for evaluating the drop test height of the filling boxes. The four-corner drop test (ASTM D5276) was conducted 24 hours after filling, with the first failure occurring at a height of 1.8 meters.

[0109] Although the cartons were formed using thermostatic strips on the ESSibox machine, preliminary evaluations indicated that employing a more advanced transverse sealing method (such as ultrasonic sealing) could increase production speed. In ultrasonic sealing, heat is generated within the material being welded (rather than in thermostatic sealing where the temperature of the jaws transfers heat from the outside of the packaging to the inside). Tests conducted using the material from Example #4 with a 30 kHz ultrasonic welding apparatus showed a sealing time of 110 milliseconds for an excellent seal, with virtually no markings on the outside of the sheet.

[0110]

[0111]

[0112] In summary, it should be understood that although many aspects of this specification have been emphasized with reference to specific embodiments, those skilled in the art will readily recognize that these disclosed embodiments are merely illustrative of the principles of the subject matter disclosed herein. Therefore, it should be understood that the disclosed subject matter is by no means limited to the specific compounds, compositions, articles, apparatus, methods, schemes, and / or reagents described herein, unless explicitly stated otherwise. Furthermore, those skilled in the art will recognize that various changes, modifications, substitutions, adjustments, additions, deletions, and combinations thereof can be made based on the teachings herein without departing from the spirit of this specification.

[0113] The use of the terms "may" or "may" with reference to a particular embodiment or aspect thereof is also accompanied by alternative meanings of "may not" or "cannot." Therefore, if this specification discloses an embodiment or aspect thereof that can or is capable of being part of the subject matter of the invention, it also explicitly includes a negative limitation or exclusionary condition, meaning that the embodiment or aspect thereof may not or cannot be part of the subject matter of the invention. Similarly, the use of the term "optionally" when referring to an embodiment or aspect thereof means that the embodiment or aspect thereof may or may not be part of the subject matter of the invention. Whether such a negative limitation or exclusionary condition applies depends on whether the claimed subject matter contains such a negative limitation or exclusionary condition.

[0114] While the numerical ranges and sets of values ​​within the broad scope of this invention are approximate, the numerical ranges and sets listed in the specific examples have been reported as precisely as possible. However, any numerical range or value inevitably contains a certain degree of error, which must be due to the standard deviation of its respective test measurements. The numerical ranges of values ​​listed herein are intended only as a convenient method for individually referring to each specific value falling within that range. Unless otherwise stated herein, each specific value within a numerical range is incorporated into this specification as if it were separately listed herein.

[0115] In describing this invention (especially in the following claims), unless otherwise stated herein or explicitly contradicted by the context, the terms “a,” “an,” “the,” and similar designations used are to be construed as encompassing both the singular and plural. Furthermore, ordinal numbers used for identified elements (e.g., “first,” “second,” “third,” etc.) are used only to distinguish these elements and do not indicate or imply a necessary or limited number of such elements, nor a specific position or order of such elements, unless expressly stated otherwise. Unless otherwise stated herein or explicitly contradicted by the context, all methods described herein may be performed in any suitable order. Any examples or exemplary language provided herein (e.g., “for example”) is intended only to better illustrate the invention and does not limit the scope of other claims of the invention. No language in this specification should be construed as indicating any unclaimed element essential to the implementation of this invention.

[0116] When used in claims, the open-ended transitional word "comprising" (and its equivalent open-ended phrases, such as "comprising," "containing," and "having"), whether added at the time of filing or in amendment, covers all expressly listed elements, limitations, steps, and / or features, whether used alone or in combination with unlisted subject matter; the listed elements, limitations, and / or features are essential, but other unlisted elements, limitations, and / or features may be added and still constitute the structure within the scope of the claims. The specific embodiments disclosed herein may be further defined in claims using the closed transitional phrases "consisting of" or "mainly composed of," instead of or modified to "comprising." When used in claims, the closed transitional phrase "consisting of," whether added at the time of filing or in amendment, excludes any elements, limitations, steps, or features not expressly listed in the claims. The closed transitional phrase "consisting of" limits the scope of the claims to the expressly listed elements, limitations, steps, and / or features, as well as any other elements, limitations, steps, and / or features that do not substantially affect the essential and novel features of the claimed subject matter. Therefore, the meaning of the open transition phrase "consistent with..." is defined as encompassing all expressly listed elements, limitations, steps, and / or features, as well as any optional, unspecified additional elements, limitations, steps, and / or features. The meaning of the closed transition phrase "consistent with..." includes only the elements, limitations, steps, and / or features expressly listed in the claims; while the meaning of the closed transition phrase "consistent with..." includes only the elements, limitations, steps, and / or features expressly listed in the claims, as well as elements, limitations, steps, and / or features that do not substantially affect the basic and novel features of the claimed subject matter. Therefore, the meaning of the open transition phrase "comprising" (and its equivalents) as a limiting case includes the claimed subject matter specified by the closed transition phrase "consistent with..." or "consistent with...". Therefore, the embodiments described or claimed herein that use the phrase "comprising" have been explicitly or inherently described, implemented, and supported by both the phrases "consistent with..." and "consistent with...".

[0117] All patents, patent publications, and other publications referenced and specified in this specification are expressly incorporated herein by reference in their entirety for the purpose of describing and disclosing, for example, combinations and methods described in such publications that may be relevant to the present invention. These publications are intended solely to disclose information prior to the filing date of this application. Nothing of this kind should be construed as an admission that the inventor has no right to disclose such information prior to a prior invention or for any other reason. All statements regarding the dates or contents of these documents are based on information available to the applicant and do not constitute any admission of the accuracy of such dates or contents.

[0118] Finally, the terminology used herein is for describing particular embodiments only and is not intended to limit the scope of the invention, which is fully defined by the claims. Therefore, the invention is not limited to what is shown and described herein.

Claims

1. A multilayer sheet comprising a plurality of layers arranged in the following order: First hard layer; First foam layer; One or more layers of recycled material between the first foam layer and the second foam layer, and Second hard layer.

2. The multilayer sheet of claim 1 further includes an outer layer adjacent to the first rigid layer and the second rigid layer.

3. The multilayer sheet according to claim 1 or 2 further includes a third rigid layer adjacent to the second rigid layer.

4. The multilayer sheet according to any one of claims 1-3, wherein the first rigid layer comprises: a) 25-35% HDPE, 0-20% CaCO3MB, 40-70% talc MB and 0-5% TiO2MB.

5. The multilayer sheet according to any one of claims 1-4, wherein the first foam layer comprises: a) 5-15% LDPE, 5-20% talc MB, 10-35% recycled cardboard material and 25-55% HDPE, optionally wherein the recycled material comprises recycled packaging.

6. The multilayer sheet according to any one of claims 1-5, wherein the one or more recycled material layers comprise an adhesive layer.

7. The multilayer sheet according to any one of claims 1-6, wherein each of the one or more recycled material layers comprises: a) Recycled materials, wherein at least a portion of the recycled materials comprises recycled packaging; or b) Recycled materials, wherein all of the recycled materials include recycled packaging.

8. The multilayer sheet according to any one of claims 1-7, wherein the second foam layer comprises: 5-15% LDPE, 5-20% talc MB, 10-35% recycled cardboard material and 25-55% HDPE, optionally wherein the recycled material comprises recycled packaging.

9. The multilayer sheet according to any one of claims 1-8, wherein the second rigid layer comprises: a) 25-35% HDPE, 0-20% CaCO3MB, 40-70% talc MB and 0-5% TiO2MB.

10. The multilayer sheet of claim 2, wherein the outer layer comprises: a) ≥50% LDPE, and / or ≤50% HDPE.

11. The multilayer sheet of claim 3, wherein the third rigid layer comprises: a) 30% HDPE, 70% LDPE.

12. The multilayer sheet according to any one of claims 3-11, wherein: The thickness of the first hard layer is 10-50 μm; The thickness of the second hard layer is 10-50 μm; The thickness of the third hard layer is 15-50 μm; The thickness of the first foam layer is 50-300 μm; The thickness of the second foam layer is 50-300 μm; The thickness of each of the one or more recycled material layers is independently selected to be 2-25 μm; and / or The outer layer has a thickness of 10-30 μm.

13. The multilayer sheet according to any one of claims 3-11, wherein: The thickness of the first hard layer is 37 μm; The thickness of the second hard layer is 20 μm; The thickness of the third hard layer is 17 μm; The thickness of the first foam layer is 200 μm; The thickness of the second foam layer is 200 μm; The thickness of each of the one or more recycled material layers is independently selected to be 5 μm; and / or The outer layer has a thickness of 15 μm.

14. The multilayer sheet of any one of claims 3-13, wherein the first foam layer and / or the second foam layer of the multilayer sheet comprises a microfoam layer prepared by: a) injecting a supercritical gas into the layer; or b) chemical foaming due to gas release caused by an endothermic agent mixed in the layer.

15. The multilayer sheet of claim 14, wherein the gas is N2 or CO2.

16. A laminated multilayer sheet, comprising: The multilayer sheet of any one of claims 1-15 laminated to a multilayer sheet, the multilayer sheet comprising a laminate layer, an impact-resistant layer, at least one adhesive layer, a barrier layer and / or at least one packaging sealing layer.

17. The laminated multilayer sheet of claim 16, wherein the multilayer sheet comprises a plurality of layers arranged in the following order: Laminated layer; Impact-resistant layer; First adhesive layer; The barrier layer; Optionally, a second adhesive layer; First packaging sealing layer; and Optional, a second packaging sealing layer.

18. The laminated multilayer film of claim 16 or 17, wherein the laminate comprises: a) A mixture of 70% Dow Innate ST50 polyethylene and 25% TiO2, a slip agent, and an anti-blocking agent; or b) 70% metallocene linear low-density polyethylene ("mLLDPE"), TiO2MB, lubricant and antiblocking agent.

19. The laminated multilayer sheet according to any one of claims 16-18, wherein the impact-resistant layer comprises: a) 75% Dow Innate ST50 polyethylene and 25% LDPE.

20. The laminated multilayer sheet of any one of claims 16-19, wherein the first adhesive layer and / or the second adhesive layer each independently comprises: a) 30% Bondyram 5101 (maleic anhydride) or Bondyram TL 4108 (maleic anhydride modified polyethylene); and 70% Dow Innate ST50 polyethylene; or b) mLLDPE-based maleic anhydride co-extruded adhesive layer mixture.

21. The laminated multilayer sheet according to any one of claims 16-20, wherein the barrier layer comprises: a) 100% Kuraray F171 EVOH; or b) 28-45% ethylene EVOH oxygen barrier resin; or c) Grinloop GLHP09PE-based oxygen barrier material obtained from AxiPolymer (Montreal, Canada).

22. The laminated multilayer sheet of any one of claims 16-21, wherein the first packaging sealing layer and / or the second packaging sealing layer each independently comprises: a) 31% Dow Innate ST50 polyethylene, 60% Dow Engage 8770 plastide or Dow Affinity VP8770G1 plastide, and 9% trace additives; or b) 28-45% ethylene EVOH oxygen barrier resin.

23. The laminated multilayer sheet according to any one of claims 17-22, wherein: The thickness of the laminate is 10-30 μm; The thickness of the impact-resistant layer is 10-30 μm; The thicknesses of the first adhesive layer and the second adhesive layer are each independently selected to be 2-10 μm; The thickness of the barrier layer is 2-15 μm; and / or The thickness of the first and second packaging sealing layers is independently selected to be 10-40 μm.

24. The laminated multilayer sheet according to any one of claims 17-22, wherein: The thickness of the laminate is 10-20 μm; The thickness of the impact-resistant layer is 10-20 μm; The thicknesses of the first adhesive layer and the second adhesive layer are each independently selected to be 2-10 μm; The thickness of the barrier layer is 2-10 μm; The thickness of the first packaging sealing layer and the second packaging sealing layer are each independently selected to be 10-20 μm.

25. A method for manufacturing aseptic packaging, comprising: a) Provide a multilayer sheet according to any one of claims 1-15, wherein the multilayer sheet has a thickness of 200-800 μm and a nominal bending stiffness of 30-500 Taber units; b) Cut one or more holes through the multilayer sheet; c) Forming a laminated multilayer sheet by laminating the multilayer sheet cut in step b) onto a multilayer sheet, wherein the multilayer sheet includes a laminate layer, an impact-resistant layer, at least one adhesive layer, a barrier layer, and at least one packaging sealing layer, wherein the lamination results in the one or more pores being covered by the multilayer sheet; d) Aseptic packaging with creases is formed by adding one or more creases to the laminated multilayer sheet; e) Optionally, the aseptic packaging with the creases is wound into a roll.

26. The method of claim 25, wherein the nominal bending stiffness is measured at 15°.

27. The method of claim 25 or 26, wherein the multilayer sheet provided in step a) comprises at least 5%, 10%, 15%, 20%, 25%, 30% or 35% recycled polyolefin.

28. The method according to any one of claims 25-27, further comprising the following steps: Prior to step b), the double sides of the multilayer sheet provided in step a) are surface treated to increase the energy of the surface of the multilayer sheet laterally to a minimum of 35 dynes, while shielding the longitudinal overlapping sealing area on the surface.

29. The method according to any one of claims 25-28, further comprising the step of: after surface treating both sides of the multilayer sheet, printing on at least one side of the multilayer sheet provided in step a).

30. The method of claim 29, wherein the printing: a) Coated with a two-component varnish that protects the ink from hydrogen peroxide and increases its resistance to high-temperature hot air in sterile chambers; and / or b) Includes two sets of registration marks, one set for indentation operations and one set for matching with roll-feed filling machines; Optionally, the ink packaging used in the printing is also resistant to hydrogen peroxide.

31. The method of any one of claims 25-30, wherein steps b) to d) are performed using a multi-die rotary crease machine, wherein the first die is configured to cut one or more holes through the multilayer sheet, a barrier film is laminated to the non-printing surface of the multilayer sheet, and a second die adds one or more creases to the laminated multilayer film.

32. The method of any one of claims 25-30, wherein steps b) to d) are performed using a multi-die rotary crease machine, wherein the first die is configured to insert a perforated rectangle into the rigid sheet to form a removable nozzle at one or both folding corners of the finished box, a barrier film is laminated to the non-printing surface of the multilayer film, and a second die adds one or more creases to the laminated multilayer film.

33. The method of any one of claims 25-31, wherein one or more creases added to the multilayer sheet in step d) are configured to fold the laminated multilayer sheet into a rigid box.

34. A method for filling aseptic packaging, comprising: a) Providing a crease-free aseptic package according to any one of claims 25-33, wherein the crease-free aseptic package is wound into a roll; b) Sterilizing the creased aseptic packaging by feeding the roll into a roll-fed aseptic filling machine, the roll-fed aseptic filling machine being configured to sterilize the creased aseptic packaging by passing it through a heat bath containing hydrogen peroxide, optionally wherein the bath temperature is in the range of 40-80°C and the weight concentration of hydrogen peroxide is 20-50%; c) After sterilization, remove hydrogen peroxide from the sterilized packaging with the creases; d) Fold the aseptic package with the creases into a continuous tube and seal the tube longitudinally to form a continuous liquid-tight tube; e) Fill the tube with pasteurizing liquid; f) Seal the filling tube laterally.

35. The method of claim 34, wherein step f) is performed by a roll-fed aseptic filling machine, wherein the induction-heated opposing clamp is configured to seal the filled tube by simultaneously pulling the tube through pulse heating, constant temperature heating or ultrasound after closure.

36. The method of claim 34 or 35, wherein a water ring is installed at the outlet of the sterile chamber prior to filling and packaging, and the water ring is used to spray water mist onto the packaging material during the filling tube sterilization step performed before or during step b).

37. The method of any one of claims 34-36, wherein steps d) to f) are performed in a sterile environment.

Images