Method of manufacturing a flexible barrier structure, flexible barrier structure, and apparatus for manufacturing a flexible barrier structure

Abstract

A method (100) for manufacturing a flexible barrier structure (10) is described. The method includes: pretreating (110) a flexible substrate (11) by providing (111) a beam of charged particles on the flexible substrate (11); depositing (120) a seed layer (20S) on the pretreated flexible substrate (11), depositing (130) one or more barrier layers (21) on the seed layer (20S), and plasma post-treating (140) a top layer (21T) of the one or more barrier layers (21).

Description

METHOD OF MANUFACTURING A FLEXIBLE BARRIER STRUCTURE, FLEXIBLE BARRIER STRUCTURE, AND APPARATUS FOR MANUFACTURING A FLEXIBLE BARRIER STRUCTURETECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to methods of manufacturing a flexible barrier structure, flexible barrier structures and apparatuses for manufacturing a flexible barrier structure.BACKGROUND

[0002] Coated flexible substrates, comprising polymeric flexible substrates with barrier layers deposited thereon, are extensively employed in the packaging industry for enclosing food products, chemical substances, pharmaceutical formulations, and agricultural materials. The barrier layers are specifically engineered to mitigate the ingress of moisture and / or oxygen, thereby preserving the integrity and quality of the packaged goods. Presently, barrier materials for barrier layers on flexible substrates primarily include metals (e.g., aluminum and tinplate), polymers (e.g., EVOH or PVDC), and polymers coated with thin metallic or oxide layers. The production of such coated flexible substrates typically involves depositing the barrier layer onto the surface of the polymeric flexible substrate through evaporation processes.

[0003] Although commonly used barrier layers provide good protection against moisture and / or oxygen, deterioration of their barrier properties after a certain period of time has been observed. Further, in the case where the barrier layers are damaged, for instance, during transportation of the goods protected by the coated flexible substrates, the barrier properties of the coated flexible substrates are also diminished. One of the challenges in the state of the art is ensuring adequate adhesion of the barrier layers to the flexible substrate. Pooradhesion can compromise the durability and performance of the barrier layers, leading to reduced effectiveness in protecting against moisture and / or oxygen. This issue is further exacerbated when the barrier layers are subjected to mechanical stresses, such as those encountered during transportation, downstream processing or handling, which can cause delamination or other forms of damage.

[0004] Accordingly, there is a demand for improved flexible barrier structures, improved methods of manufacturing flexible barrier structures, and improved apparatuses for manufacturing flexible barrier structures which at least partially overcome one or more of the disadvantages of the state of the art.SUMMARY

[0005] In light of the above, a method for manufacturing a flexible barrier structure, a flexible barrier structure, and an apparatus (200) for manufacturing a flexible barrier structure according to the independent claims are provided. Further aspects, benefits, and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings.

[0006] According to an aspect of the present disclosure, a method for manufacturing a flexible barrier structure is provided. The method includes pretreating a flexible substrate by providing a beam of charged particles on the flexible substrate. Additionally, the method includes depositing a seed layer on the pretreated flexible substrate. Further, the method includes depositing one or more barrier layers on the seed layer. Moreover, the method includes plasma post-treating a top layer of the one or more barrier layers.

[0007] According to another aspect of the present disclosure, a flexible barrier structure is provided. The flexible barrier structure includes a pretreated flexible substrate. The pretreated flexible substrate is pretreated by a beam of charged particles. Additionally, the flexible barrier structure includes a seedlayer on the pretreated flexible substrate. Further, the flexible barrier structure includes one or more barrier layers on the seed layer: The one or more barrier layers include a plasma post-treated top layer. In particular, the flexible barrier structure is manufactured by a method according to any embodiments described herein.

[0008] According to a further aspect of the present disclosure, an apparatus for manufacturing a flexible barrier structure is provided. The apparatus includes a vacuum chamber. Additionally, the apparatus includes a charged particle device for pretreating a flexible substrate. Further, the apparatus includes a deposition apparatus for depositing a seed layer on the flexible substrate and one or more barrier layers on the seed layer. Further, the apparatus includes a plasma device for post-treating a top layer of the one or more barrier layers. The charged particle device, the deposition apparatus, and the plasma device are provided within the vacuum chamber.

[0009] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing each described method aspect. These method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the disclosure are also directed at methods for operating the described apparatus. The methods for operating the described apparatus include method aspects for carrying out every function of the apparatus.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

[0011] FIG. 1 shows a block diagram for illustrating a method of manufacturing a flexible barrier structure according to embodiments of the present disclosure;

[0012] FIGS. 2 to 4 show block diagrams for illustrating further embodiments of the method of manufacturing a flexible barrier structure according to the present disclosure; and

[0013] FIGS. 8 and 9 show exemplary embodiments of an apparatus for manufacturing a flexible barrier structure according to the present disclosure.DETAILED DESCRIPTION OF EMBODIMENTS

[0014] Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with any other embodiment to yield yet a further embodiment. It is intended that the present disclosure includes such modifications and variations.

[0015] Within the following description of the drawings, the same reference numbers refer to the same or to similar components. Generally, only the differences with respect to the individual embodiments are described. Unless specified otherwise, the description of a part or aspect in one embodiment can apply to a corresponding part or aspect in another embodiment as well.

[0016] With exemplary reference to FIG. 1 , a method 100 for manufacturing a flexible barrier structure 10 according to embodiments of the present disclosure is described.

[0017] According to embodiments, which can be combined with other embodiments described herein, the method includes pretreating (represented by block 110 in FIG. 1 ) a flexible substrate 11 by providing (represented byblock 111 in FIG. 1 ) a beam 211 of charged particles on the flexible substrate 11. Additionally, the method includes depositing (represented by block 120 in FIG. 1 ) a seed layer 20S by depositing material on the pretreated flexible substrate 11. Further, the method 100 includes depositing (represented by block 130 in FIG.1 ) one or more barrier layers 21 on the seed layer 20S. Moreover, the method 100 includes plasma post-treating (represented by block 140 in FIG. 1 ) a top layer 21 T of the one or more barrier layers 21 . In other words, the top layer 21 T of the one or more barrier layers 21 is typically exposed to a plasma environment 30 (schematically represented by the doted wave lines in FIG. 1 ). It is to be understood that the seed layer 20S, the one or more barrier layers 21 , and the plasma post-treated top layer 21 T may be referred to as barrier coating 20.

[0018] Accordingly, compared to the state of the art, an improved method of manufacturing a flexible barrier structure is provided. In particular, the method according to embodiments described herein beneficially provides for improved adhesion of the barrier coating to the flexible substrate. Another advantage is that adhesion of the barrier coating to downstream webs or films applied in subsequent process steps can be enhanced. As a result, the overall stability and structural integrity of the flexible barrier structure is improved.

[0019] In the present disclosure, a "flexible barrier structure" can be understood as a multilayered material system configured to provide a barrier against the transmission of gases and moisture while maintaining flexibility and lightweight properties. It is to be noted, that embodiments of the flexible barrier structure are particularly well-suited for application in packaging, electronics, or photovoltaics due to their ability to combine functional protection with form adaptability.

[0001] In the present disclosure, a "flexible substrate" can be understood as a bendable substrate. For instance, the “flexible substrate” can be a “foil” or a “web”. In the present disclosure, the term “flexible substrate” and the term “substrate” may be synonymously used. For example, the flexible substrate asdescribed herein may include or consist of one or more materials selected from the group of polyolefins (PO), polyester (PES), polyurethane (Pll), polypropylene (PP), polyacrylate (PAC), polysiloxane (PSI), polydimethylsiloxane (PDMS), polycarbonate (PC), polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), triacetyl cellulose (TAC), cyclo olefin polymer (COP), polyethylene naphthalate (PEN), one or more metals, paper, and the like. According to some embodiments, the flexible substrate may be a coated substrate, for instance having a hard coating. For example, the substrate thickness can be 1 pm or more and 200 pm or less. More specifically, the substrate thickness can be selected from the range of having a lower limit of 8 pm and an upper limit of 25 pm, for instance for food packaging applications.

[0020] In the present disclosure, a “beam of charged particles " can be understood as a stream of particles that possess an electric charge (positive or negative) and move together in a directed path. For instance, the charged particulars can be ions of electrons. Pre-treating a flexible substrate by providing a beam of charged particles on the flexible substrate refers to a process in which the substrate is treated before undergoing further processing, by exposing the substrate to a beam of charged particles, typically using a particle accelerator or ion beam source. The pre-treatment with charged particles modifies the surface properties of the substrate, improving wettability, cleanliness, reactivity, and adhesion, particularly for subsequent layers.

[0021] According to embodiments, which can be combined with other embodiments described herein, providing (represented by block 111 in FIG. 1 ) the beam of charged particles on the flexible substrate 11 includes providing a charge particle dose of 4 x 1014to 6 x 1015charged particles / cm2, particularly 6 x 1 o14to 4 x 1 o15charged particles / cm2, more particularly 8 x 1 o14to 2 x 1 o15charged particles / cm2.

[0022] According to embodiments, which can be combined with other embodiments described herein, providing (represented by block 111 in FIG.1 )the beam of charged particles on the flexible substrate 11 includes providing a charged particles energy of 100 eV to 9000 eV, particularly 200 eV to 7000 eV, more particularly 400 eV to 5000 eV.

[0023] In the present disclosure, a "seed layer" can be understood as a thin film or layer of material deposited on the substrate to promote or guide the growth of another material layer during a subsequent deposition or growth process. The seed layer serves as a foundation, influencing the nucleation, orientation, and quality of the material grown on top of the seed layer. According to embodiments, which can be combined with other embodiments described herein, the seed layer is a metal oxide layer, particularly an aluminum oxide layer.

[0024] In the present disclosure, "one or more barrier layers" can be understood as at least one layer configured to prevent or reduce the transmission of substances like gases (e.g. oxygen, carbon dioxide, etc.), moisture, or other chemicals through coating. According to embodiments, which can be combined with other embodiments described herein, at least one layer of the one or more barrier layers is a metal layer, particularly an aluminum layer.

[0025] In the present disclosure, a "top layer of the one or more barrier layers" refers to the outermost layer of the one or more barrier layers. Typically, the top layer serves as the first point of contact with a subsequent film, which may be laminated on the top layer, or with the external environment. In particular, the top layer can be configured to provide specific surface properties or additional protection to the underlying layers.

[0026] In the present disclosure, "plasma post-treating" refers to the process of exposing a material to a plasma environment after a primary treatment, coating, or fabrication step to modify surface properties, particularly to improve performance of a previously applied layer. The term "plasma" typically describes a partially ionized gas composed of ions, electrons, andneutral species. The term “plasma” may also refer to a mixture of electrons and positively charged ions created when matter is continually supplied with energy, for instance, by increasing the temperature and / or applying high voltage at specific frequencies.

[0027] According to embodiments, which can be combined with other embodiments described herein, pretreating (represented by block 110 in FIG. 1 ) the flexible substrate 11 further includes conducting (represented by block 112 in FIG. 1 ) a plasma pre-treatment of the flexible substrate 11 . In the present disclosure, a "plasma pre-treatment of the flexible substrate" refers to a process of exposing the substrate to a plasma environment before a primary processing step, such as coating or laminating. Typically, the plasma pretreatment results in a modification of the surface properties of the substrate. In particular, the plasma pre-treatment may improve wettability, cleanliness, reactivity, and adhesion, particularly for subsequent layers.

[0028] The combined use of charged particle pre-treatment and plasma pre-treatment offers several synergistic advantages that can enhance the surface properties of materials. In particular, the combination of charged particle pre-treatment and plasma pre-treatment provide for improved surface activation and functionalization, increasing reactivity and bonding strength of the substrate, such that adhesion to subsequent layers can be improved.

[0029] Further, the charged particle pre-treatment and the plasma pretreatment work together to optimize surface wettability, enabling liquids to spread more evenly, which is crucial for subsequent coating or printing applications. Moreover, the combination ensures a more thorough cleaning of the substrate by removing contaminants at both the macro and molecular levels, thus improving surface cleanliness and reducing defects in later processing stages.

[0030] According to embodiments, which can be combined with other embodiments described herein, plasma post-treating (represented by block140 in FIG. 3) the top layer 21 T of the one or more barrier layers 21 includes creating (represented by block 141 in FIG. 3) a passivation layer 20P. The term “passivation layer” can be understood as a protective layer that is configured material to improve stability and resistance to environmental factors. In particular, the passivation layer formed during plasma posttreatment serves as a protective barrier that enhances resistance to oxidation. By stabilizing the surface, the passivation layer prevents further degradation and ensures the durability of the underlying material. This protective layer also increases the longevity of the coating by shielding it from environmental stresses and can make the surface chemically inert, thereby reducing the risk of unwanted reactions or contamination.

[0031] According to embodiments, which can be combined with other embodiments described herein, the passivation layer 20P is a metal oxide layer, particularly an aluminum oxide layer.

[0032] According to embodiments, which can be combined with other embodiments described herein, plasma post-treating (represented by block 140 in FIG. 1 ) the top layer 21 T of the one or more barrier layers 21 comprises employing a process gas. Typically, the process gas includes oxygen and an inert gas. In particular, the process gas includes oxygen, nitrogen and an inert gas. For instance, the inert gas can be argon, helium or neon.

[0033] According to embodiments, which can be combined with other embodiments described herein, the method further includes laminating (represented by block 150 in FIG.4) a film 12 onto the top layer 21 T of the one or more barrier layers 21. The film 12 can be a further flexible substrate as described herein.

[0034] According to an embodiment, which may be combined with other embodiments described herein, the film 12 may include a printed film or a colored film. In other words, the film 12 may be provided with a layer of printed material prior to the film 12 being laminated to the top layer 21 T of the one ormore barrier layers 21 , or the film 12 may be formed from a material having a coloring treatment, e.g. a tinting treatment, applied thereto.

[0035] It is to be understood, that with the method 100 according to embodiments described herein, a flexible barrier structure 10 as exemplarily shown in FIGS. 1 to 7 can be produced. In other words, embodiments of the flexible barrier structure 10 are typically manufactured by a method 100 according to embodiments described herein.

[0036] As exemplarily shown in FIG. 1 , according to embodiments, which can be combined with other embodiments described herein, the flexible barrier structure 10 includes a pretreated flexible substrate 11 . The pretreated flexible substrate is pretreated by a beam of charged particles. Additionally, the flexible barrier structure 10 includes a seed layer 20S on the pretreated flexible substrate 11. Further, the flexible barrier structure 10 includes one or more barrier layers 21 on the seed layer 20S. The one or more barrier layers 21 comprise a plasma post-treated top layer 21 T. FIGS. 1 to 4 show examples with only one barrier layer 21. Accordingly, as indicated in FIG. 1 , the barrier layer 21 is also the top layer 21 T. FIG. 5 shows an example in which the one or more barrier layers 21 include a first barrier layer 21 a and a second barrier layer 21 b. Accordingly, the second barrier layer 21 b represents the top layer 21 T. With exemplary reference to FIG. 6, it is to be understood that more than two barrier layers 21 may be provided, particularly a first barrier layer 21 a, a second barrier layer 21 b, and one or more further barrier layers 21 x.

[0037] According to embodiments, which can be combined with other embodiments described herein, the Oxygen Transmission Rate (OTR) of the barrier structure 10 is OTR < 15 cm3 / m2per day, particularly OTR < 10 cm3 / m2. The OTR is a measure of how much oxygen gas passes through a material or barrier over a specific period of time (such as a day), typically expressed as the volume of oxygen (in cubic centimeters) that permeates through a unit area of the material (usually measured in m2) under controlled conditions, such as temperature and humidity.

[0038] The OTR is measured by determining the amount of oxygen that permeates through the material or sample of interest over a specific period of time under controlled environmental conditions. The measurement is typically performed using an oxygen permeability tester, which is designed to assess the gas diffusion through films, coatings, or other barrier materials. The amount of oxygen passing through the material is detected by sensors, and the rate of transmission is calculated based on the volume of oxygen, the sample area, and the time. Standard laboratory environmental conditions for temperature and humidity for measuring OTR are typically 23°C ± 2°C and a relative humidity of 50% ± 5%.

[0039] According to embodiments, which can be combined with other embodiments described herein, the water vapor transmission rate WVTR of the barrier structure 10 is VWTR < 0.3 g / m2per day, particularly WVTR < 0.2 g / m2per day, more particularly WVTR < 0.1 g / m2per day. The water vapor transmission rate WVTR is a measure of the rate at which water vapor permeates through a material or barrier over a specific period of time. It quantifies the amount of moisture that passes through the material, typically measured in grams of water vapor per unit area (usually m2) per unit of time (such as a day). The WVTR is typically measured using standardized testing methods that quantify the amount of water vapor that permeates through a material or sample of interest over a specified period of time. Standard laboratory environmental conditions for temperature and humidity for measuring WVTR are typically 23°C ± 2°C and a relative humidity of 50% ± 5%. The most common method for measuring WVTR is the desiccant method (cup method), where a material is exposed to a desiccant that absorbs water vapor. By measuring the weight gain of the desiccant, the WVTR is determined. Other methods include the gravimetric method, molecular sieve method, and water vapor sensor method. In all cases, temperature and humidity are strictly controlled to ensure the accuracy and consistency of the results.

[0040] According to embodiments, which can be combined with other embodiments described herein, wherein the Bond Strength (BS) of the barrier coating 20 to the first flexible substrate is BS > 2.5 N / 15 mm, particularly BS > 3.0 N / 15 mm, more particularly BS > 3.5 N / 15 mm. Typically, the barrier coating 20 includes a seed layer 20S as described herein, one or more barrier layers 21 as described herein, and a plasma post-treated top layer 21 T as described herein.

[0041] BS refers to the measure of the adhesive force that holds two materials together, specifically the adhesion of one material to another. In this context, BS refers to the strength of the bond between the barrier coating and the first flexible substrate. The BS is an important property for ensuring that the barrier coating remains securely attached to the substrate, especially under stress or external forces, such as stretching, bending, or environmental conditions. In particular, the BS is defined as the force (measured in Newtons, N) required to break the bond between the barrier coating and the flexible substrate, when the bond is applied over a defined width (in this case, 15 mm). For instance, BS > 3.0 N / 15 mm indicates that the BS of the barrier coating to the flexible substrate is at least 3.0 Newtons per 15 millimeters of width.

[0042] The BS is typically measured by performing a peel test or tensile test on the coated substrate. During the test, a section of the flexible substrate with the barrier coating is subjected to a force that attempts to separate the coating from the substrate. The force at which the coating separates (i.e. , the bond is broken) is recorded.

[0043] In the peel test, one end of the coated substrate is peeled away from the other at a defined angle (typically 90° or 180°) and speed. The force required to peel the coating off is measured, and the BS is calculated based on the force and the width of the material (15 mm according to embodiments of the present disclosure). Alternatively, a tensile test can be conducted, where a strip of the coated substrate is pulled apart. The amount of force required to break the bond between the coating and the substrate is measured.

[0044] With exemplary reference to FIGS. 8 and 9, an apparatus 200 for manufacturing a flexible barrier structure according to embodiments of the present disclosure is described.

[0045] According to embodiments, which can be combined with other embodiments described herein, the apparatus 200 includes a vacuum chamber 201. The vacuum chamber 201 may be at a pressure below atmospheric pressure. For instance, the apparatus 200 may include equipment allowing for generating or maintaining a vacuum in the vacuum chamber 201 . In particular, the apparatus 200 may include vacuum pumps, evacuation ducts, vacuum seals and the like for generating or maintaining the vacuum in the vacuum chamber 201. For instance, the vacuum chamber 201 may have one or more vacuum pumps for evacuating the vacuum chamber. In some embodiments, two or more turbo-vacuum pumps may be connected to the vacuum chamber 201 .

[0046] The term “vacuum”, as used herein, can be understood in the sense of a technical vacuum having a vacuum pressure of less than 10 mbar, for example, 10’3mbar. Typically, the pressure in a vacuum chamber as described herein, may be between 10’3mbar and about 10’8mbar, more typically, between 10’5mbar and 10’7mbar, and even more typically, between about 10’6mbar and about 10’7mbar.

[0047] Additionally, the apparatus 200 includes a charged particle device 210 for pretreating a flexible substrate 11 . In the present disclosure, a “charged particle device” can be understood as a system or tool configured for providing a beam of charged particles as described herein.

[0048] Further, the apparatus 200 includes a deposition apparatus 220 for depositing a seed layer 20S on the flexible substrate 11 and one or more barrier layers 21 on the seed layer 20S. In the present disclosure, a “deposition apparatus” may be understood as an apparatus configured for depositing material on a flexible substrate. For example, the deposition apparatus 200may be a physical vapor deposition (PVD) apparatus, a chemical vapor deposition (CVD) apparatus, an evaporation deposition apparatus, or another deposition apparatus known in the art.

[0049] As exemplarily shown in FIGS. 8 and 9, the apparatus 200 for manufacturing a flexible barrier structure 10 may include a deposition drum 202. In the present disclosure, a “deposition drum” can be understood as a drum or a roller having a film support surface for contacting the substrate. In particular, the deposition drum 202 may be rotatable about a rotation axis and may include a substrate guiding region. Typically, the substrate guiding region is a curved film support surface, e.g. a cylindrically symmetric surface, of the deposition drum 202. The curved substrate support surface of the deposition drum may be adapted to be (at least partly) in contact with the substrate during operation of the apparatus 200. The deposition drum 202 may be heated or cooled depending on the material to be deposited. The apparatus 200 exemplarily shown in FIGS. 8 and 9 includes a deposition drum 202, however, the present disclosure is not limited thereto. For example, the substrate 11 may be transported past the deposition apparatus 220 by spanning the substrate 11 between two rollers.

[0050] The deposition apparatus 220 may include at least one deposition unit. Particularly, the deposition apparatus may include a plurality of deposition units. During guiding of the substrate 11 by the deposition drum 202 past the deposition apparatus 220, the substrate may be in direct contact with the substrate support surface of the deposition drum 202. As the deposition drum 202 rotates, the film is guided past the deposition units which face toward the curved substrate support surface of the deposition drum, so that the substrate can be coated with one or more layers of deposited material while being moved past the deposition units at a predetermined speed. The deposition units may include a deposition source configured for providing a material for depositing layers as described herein, e.g. the seed layer and the one or more barrier layers.

[0051] Moreover, the apparatus 200 includes a plasma device 230 for posttreating 140 a top layer 21 T of the one or more barrier layers 21 . The charged particle device 210, the deposition apparatus 220, and the plasma device 230 are provided within the vacuum chamber 201 . In the present disclosure, a “plasma device” can be understood as a system or tool configured to provide a plasma as described herein.

[0052] According to embodiments, which can be combined with other embodiments described herein, the apparatus 200 may include a further plasma device 231 for conducting a plasma pre-treatment of the flexible substrate 11 , as exemplarily shown in FIG. 9.

[0053] With exemplary reference to FIG. 9, according to embodiments, which can be combined with other embodiments described herein, the apparatus 200 may further include a laminating apparatus 240 for laminating a film 12 onto the top layer 21 T of the one or more barrier layers 21 . Typically, the laminating apparatus 240 is provided within the vacuum chamber 201 .

[0054] In the present disclosure, a “laminating apparatus” can be understood as an apparatus configured to join a coated flexible substrate with a further film to each other, to produce a composite flexible structure. The laminating apparatus may include a pair of pinch rollers configured for bringing the coated flexible substrate and the film to be laminated into contact with each other, and for applying pressure to the stack of the coated flexible substrate, and the further film so that the stack is laminated together.

[0055] According to an embodiment, which may be combined with other embodiments described herein, the laminating apparatus 240 may include a thermal laminating apparatus. A thermal lamination apparatus joins two or more films using a thermally-activated lamination layer by applying heat and pressure to laminate the films together. Thermal lamination may be advantageous over common techniques, e.g. solvent lamination, as there is no wet coating process to manage. For example, thermal lamination can avoidthe providing and storing coating solution or the use of a complex coating head or drying ovens, and potential splashing of solvents. Subsequent cleanup can also be avoided. Further, thermal lamination has minimal curing time in comparison to common lamination techniques. The Laminating apparatus may include, for example, a heater configured to heat the stack of the coated flexible substrate and the further film, such that they are thermally joined to each other to form a composite flexible barrier structure.

[0056] In view of the above, it is to be understood that the embodiments of the present disclosure represent advancements that effectively address the limitations and challenges present in the state of the art. Specifically, the described embodiments offer a notable improvement in the adhesion between the barrier coating and the flexible substrate, a critical factor in ensuring the reliability and durability of the barrier structure. This enhanced adhesion minimizes the risk of delamination and maintains the protective performance of the barrier coating under various operational and environmental stresses.

[0057] Moreover, the embodiments described herein also facilitate stronger adhesion of the barrier coating to additional webs or films applied in subsequent processing stages, such as lamination or coating. This feature is particularly advantageous for producing multilayered structures, where robust interlayer adhesion is essential to maintaining the structural integrity and functional performance of the final product.

[0058] By improving both initial adhesion and downstream compatibility, embodiments of the present disclosure ensure a more stable and durable flexible barrier structure, capable of withstanding mechanical stresses, such as those encountered during handling, transportation, and end-use applications. These advancements collectively enhance the reliability, longevity, and performance of the barrier structure, making it highly suitable for demanding packaging and protective applications.

[0059] While the foregoing is directed to embodiments of the disclosure,other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

[0060] In particular, this written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any devices or systems and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if the claims have structural elements that do not differ from the literal language of the claims, or if the claims include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

WHAT IS CLAIMED:

1. A method (100) of manufacturing a flexible barrier structure (10), comprising:- pretreating (110) a flexible substrate (11 ) by providing (111 ) a beam (211 ) of charged particles on the flexible substrate (11 );- depositing (120) a seed layer (20S) on the pretreated flexible substrate (11 ),- depositing (130) one or more barrier layers (21 ) on the seed layer (20S), and- plasma post-treating (140) a top layer (21 T) of the one or more barrier layers (21 ).

2. The method (100) of claim 1 , wherein pretreating (110) the flexible substrate (11 ) further comprises conducting (112) a plasma pre-treatment of the flexible substrate (11 ).

3. The method (100) of claim 1 or 2, wherein plasma post-treating (130) the top layer (21 ) comprises creating (141 ) a passivation layer (20P).

4. The method (100) of any of claims 1 to 3, wherein providing (111 ) the beam of charged particles on the flexible substrate (11 ) comprises providing a charge particle dose of 4 x 1014to 6 x 1015charged particles / cm2, particularly 6 x 1014to 4 x 1015charged particles / cm2, more particularly 8 x 1014to 2 x i o15charged particles / cm2.

5. The method (100) of any of claims 1 to 4, wherein providing (111 ) the beam of charged particles on the flexible substrate (11 ) comprises providing a charged particles energy of 100 eV to 9000 eV, particularly 200 eV to 7000 eV, more particularly 400 eV to 5000 eV.

6. The method (100) of any of claims 1 to 5, wherein plasma posttreating (140) the top layer (21T) comprises employing a process gas comprising oxygen and an inert gas, particularly the process gas comprising oxygen, nitrogen and an inert gas, particularly at least one of argon, helium and neon.

7. The method (100) of any of claims 1 to 5, wherein the flexible substrate comprises a polymer material selected from the group consisting polyolefin (PO), polyester (PES), polyurethane (Pll), polypropylene (PP), polyacrylate (PAC), polysiloxane (PSI), polydimethylsiloxane (PDMS), polycarbonate (PC), polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), triacetyl cellulose (TAC), cyclo olefin polymer (COP), polyethylene naphthalate (PEN), and combinations thereof.

8. The method (100) of any of claims 1 to 7, wherein the seed layer (20S) is a metal oxide layer, particularly an aluminum oxide layer.

9. The method (100) of any of claims 1 to 7, wherein at least one layer of the one or more barrier layers (21 ) is a metal layer, particularly an aluminum layer.

10. The method (100) of any of claims 1 to 9 in combination with claim 3, wherein the passivation layer (20P) is a metal oxide layer, particularly an aluminum oxide layer.

11. The method (100) of any of claims 1 to 10, further comprising laminating (150) a film (12) onto the top layer (21 T) of the one or more barrier layers (21 ).

12. A flexible barrier structure (10), comprising:- a pretreated flexible substrate (11 ), the pretreated flexible substrate (11 ) being pretreated by a beam of charged particles,- a seed layer (20S) on the pretreated flexible substrate (11 ),- a one or more barrier layers (21 ) on the seed layer (20S), wherein the of one or more barrier layers (21 ) comprise a plasma post-treated top layer (21 T), particularly wherein the flexible barrier structure (10) is manufactured by a method (100) according to any of claims 1 to 11 .

13. The flexible barrier structure (10) of claim 12, wherein the oxygen transmission rate OTR of the barrier structure (10) is OTR < 15 cm3 / m2per day, particularly OTR < 10 cm3 / m2.

14. The flexible barrier structure (10) of claim 12 or 13, wherein the water vapor transmission rate WVTR of the barrier structure (10) is WVTR < 0.3 g / m2per day, particularly WVTR < 0.2 g / m2per day, more particularly WVTR < 0.1 g / m2per day.

15. The flexible barrier structure (10) of any of claims 12 to 14, wherein the seed layer (20S), the one or more barrier layers (21 ), and the plasma posttreated top layer (21 T) constitute a barrier coating (20), and wherein the bond strength BS of the barrier coating (20) to the first flexible substrate is BS > 2.5 N / 15 mm, particularly BS > 3.0 N / 15 mm, more particularly BS > 3.5 N / 15 mm.

16. An apparatus (200) for manufacturing a flexible barrier structure (10), comprising:- a vacuum chamber (201 );- a charged particle device (210) for pretreating a flexible substrate (11 )- a deposition apparatus (220) for depositing a seed layer (20S) on the flexible substrate (11 ) and one or more barrier layers (21 ) on the seed layer (20S); and- a plasma device (230) for post-treating (140) a top layer (21 T) of the one or more barrier layers (21 ), wherein the charged particle device (210), the deposition apparatus (220), and the plasma device (230) are provided within the vacuum chamber.

17. The apparatus of claim 16, further comprising a further plasma device (231 ) for conducting a plasma pre-treatment of the flexible substrate (11 ).

18. The apparatus of claim 16 or 17, further comprising a laminating apparatus (240) for laminating a film (12) onto the top layer (21 T) of the one or more barrier layers (21 ) , wherein the laminating apparatus (240) is provided within the vacuum chamber (201 ).

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