TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to a method for manufacturing a food packaging material. Particularly, the present disclosure relates to a method for manufacturing an eco-friendly food packaging material. Embodiments of the present disclosure further relate to an apparatus for manufacturing the food packaging material, in particular an eco-friendly food packaging material, and a food packaging material, in particular an eco-friendly food packaging material.

BACKGROUND

[0002] There is a high need for single-use food packaging material which can be employed for aseptic packaging of liquid foods such as milk, fruit juices etc, sold for long term ambient storage but also for solid foods such as convenience products, fast food and snacks etc. Whereas the use of pure aluminum was usual in the past, for environment and cost reasons, modern packaging is usually made from a thermoplastic that is coated with a thin layer of metal. Such a composite can provide the needed stability, the required liquid-tight and gas-tight property and, if needed, the anti-septic property of the packaging material.

[0003] However, the packaging material as described also has various drawbacks. In particular, packaging including polymers is more and more perceived as harmful to the environment by customers, and food producers are afraid that customers feel less inclined to acquire their products if not provided in a more environmentally friendly packaging.

[0004] Therefore, various attempts have been made to coat a paper material, instead of a polymeric material, with a metal layer. However, while the replacement of polymer with paper has advantages with regard to the customer perceiving the packaging as eco-friendly, it turns out that the thus produced packaging material is often insufficient in quality.

[0005] In view of the above, there remains a need for a food packaging material as well as methods and apparatuses for manufacturing a food packaging material having high quality with increased environmental sustainability.

SUMMARY

[0006] In light of the above, a method for producing a food packaging material is provided. Further, an apparatus for producing a food packaging material is provided. Further, a food packaging material is provided. Further aspects, benefits, details and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings.

[0007] According to one aspect of the present disclosure, a method for producing a food packaging material is provided. The method includes, in a vacuum environment, providing a supporting substrate; providing a release layer; coating with a vacuum deposited layer; providing a top coat layer; wherein at least the release layer, the vacuum deposited layer and the top coat layer form a first layer stack. The method further includes providing a bio-degradable material; bonding the first layer stack to the bio-degradable material; and removing the supporting substrate from the first layer stack with at least the vacuum deposited layer, the top coat layer and the bio-degradable material forming a second layer stack.

[0008] According to a further aspect of the present disclosure, an apparatus for producing a food packaging material is provided. The apparatus includes a vacuum chamber which includes a deposition device for depositing a vacuum deposited layer above a supporting substrate; and a top coat layer applicator for applying a top coat layer. The apparatus further includes a first guide for providing a bio-degradable material; a bonding agent applicator; and a second guide for collecting the supporting substrate.

[0009] According to a further aspect of the present disclosure, a food packaging material is provided. The food packaging material includes the following layers: a bio-degradable material; a bonding agent; a top coat layer produced under vacuum conditions; and a vacuum deposited layer produced under vacuum conditions.

[0010] Further aspects, advantages, and features of the present disclosure will be described in the following the description, the accompanying drawings and the dependent claims.

[0011] The aspects of the present disclosure allow for the quality of the resulting packaging material to be high. At the same time, the use of a bio-degradable material instead of plastic, which has commonly been used until now, increases the environmental sustainability and thus customers are more likely to acquire food products contained in the food packaging material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] 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. Typical embodiments are depicted in the drawings and are detailed in the description which follows.

FIG. 1 shows a schematic view of a coating chamber forming part of an apparatus for manufacturing a food packaging material according to embodiments described herein;

FIG. 2 shows a schematic view of parts of an apparatus for manufacturing a food packaging material according to embodiments described herein;

FIG. 3 schematically illustrates the sequence of embodiments of the method as disclosed herein, by exemplarily illustrating (a) the first layer stack, (b) the connection of the first layer stack with the bio-degradable material, and (c) food packaging material as described herein;

FIG. 4 schematically illustrates the sequence of embodiments of the method as disclosed herein, by exemplarily illustrating (a) the first layer stack, (b) the connection of the first layer stack with the bio-degradable material, and (c) food packaging material as described herein; FIG. 5 shows a schematic view of a coating chamber of an apparatus for manufacturing a food packaging material according to embodiments described herein;

FIG. 6 shows a schematic view of a coating chamber of an apparatus for manufacturing a food packaging material according to embodiments described herein;

FIG. 7 is a flow diagram of a method of producing a food packaging product according to embodiments described herein.

DETAILED DESCRIPTION

[0013] 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.

[0014] 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 applies to a corresponding part or aspect in another embodiment as well.

[0015] The inventors of the present disclosure have found a number of reasons for the unsatisfactory quality of packaging materials that are produced by depositing paper with a layer, such as a metallization layer, under vacuum. In particular, the roughness of the paper surface causes an uneven deposition, in the worst case resulting in interruptions, defects and cracks. Further, under vacuum, the paper degases which regularly jeopardizes the vacuum and consequently worsens the deposition process. Furthermore, known techniques for coating paper with a layer under vacuum are slow. In addition, the typical coating process includes the action of loading the uncoated paper roll into the vacuum chamber, evacuating the vacuum chamber, performing the deposition, and afterwards venting the vacuum chamber again to withdraw the coated paper roll. Then, another uncoated paper roll for subsequent coating can be added. A high share of the processing time is thus used up by creating a vacuum for each new paper roll, and it is an overall goal to reduce the processing time. [0016] A high quality and economic coating benefits from deposition under vacuum conditions. Non-vacuum driven processes, such as gluing an aluminum layer to paper, normally require a thick aluminum layer which is cost intensive and, at the same time, against the goal of economic sustainability. In addition, handling aluminum in a non-vacuum environment regularly results in damages to the aluminum which can cause the food packaging material to deteriorate. For instance, the exposed metal layer may be damaged or oxidized. For example, if the exposed deposited layer contacts a roller or passes through a gate valve, the fragile layers of deposited or printed material, such as metal and particularly Aluminum, may be particularly susceptible to damage, e.g. by scratching, rubbing or marring. Further, if an exposed deposited layer, particularly a metallic layer, passes through a processing chamber containing air or oxygen, the deposited layer may become oxidized before one or more further protective top coating layers can be coated thereon. A deposited layer which is damaged or oxidized leads to a reduced quality of the resulting composite film.

[0017] Thus, the present search and development in the technology of producing sustainable food packaging material aims at improving deposition on paper in the vacuum environment of a coating chamber.

[0018] In contrast, the present inventors had the idea to provide a method and apparatus for the production of food packaging material that benefits from vacuum deposition, yet avoiding the mentioned problems of depositing layers on paper under vacuum. The proposed process has a number of advantages:

• The bio-degradable material, such as paper, is not needed in the vacuum chamber during deposition of the vacuum deposited layer. The bio-degradable material therefore does not pollute the vacuum and consequently does not disturb the deposition process, such as the metallization process.

• For this reason, there is no need to pre-condition the bio-degradable material due to the moisture inherent in the bio-degradable material. The drying times for the bio-degradable material before processing become less important and can consequently be reduced thereby reducing the overall complexity and costs of the process.

• The surface of the bio-degradable material, in particular the unevenness and inhomogeneities of the surface, no longer play a central role since the vacuum deposition is not performed on the bio-degradable material; by bonding the stack including the deposited layer to the bio-degradable material, the inhomogeneities and unevenesses are no longer problematic.

• The deposition process can benefit from the long existing experience in deposition on a supporting substrate, which is typically a polymeric material.

• The supporting substrate can be re-used several times, for instance at least three times, or even at least five times. This is highly advantageous with regard to environmental sustainability.

• The supporting substrate can be chosen from a material where a small thickness is sufficient. For instance, as used herein, a supporting substrate with a thickness of less than 10 microns can be used which is typically a polymeric material, such as an oriented polyethylene terephthalate (OPET). The length of supporting substrate foil that fits to a roll is drastically longer as compared to the length of, e.g., a paper roll with the same radius. For instance, state-of-the art paper coating techniques use a paper thickness of at least 45 microns. Indeed, in this example, the length of foil is 4.5 times more for the OPET foil than for the paper. Thus, the produced length of produced foil per venting action is increased, reducing the production costs. Put in other words, per produced meter of foil, 4.5 times fewer venting actions are necessary.

• The handling of the exposed deposited layer, such as a deposited aluminum layer, outside of the vacuum is avoided. This is because the deposition is performed on the supporting substrate or rather on a release layer. The deposited layer is subsequently covered by a top coat layer whilst still within the vacuum chamber. The top coat layer may be printed by a vacuum chamber printing process. Alternatively, the top coat layer may be laminated to the vacuum deposited layer whilst still within the coating chamber. Consequently, once the first layer stack is rolled up within the vacuum chamber, the deposited layer is protected on both sides which simplifies the subsequent processing in the non-vacuum environment.

For bonding the first stack to the bio-degradable material, such as paper, the composite of the deposition layer and the top coat layer (and possibly the release layer and/or lacquer layer) is released as one layer stack. Thus, the integrity of the first layer stack is preserved until the bonding takes place, and the sandwiched deposited layer is protected throughout this whole process.

[0019] Within the vacuum chamber, the supporting substrate, which is typically a flexible substrate such as a polymeric foil, is processed while being moved past processing equipment. The flexible substrate may be made from a polymer, in particular from a polyester, more particularly from a polyethylene terephthalate (PET), more particularly from an oriented PET (OPET), biaxially- oriented polyethylene terephthalate (BOPET), and/or bi-axial Oriented Polypropylene (BOPP). The flexible substrate may be provided on a roll to the vacuum chamber. The flexible substrate is provided with the release layer on top. In embodiments, the release layer is coated on the flexible substrate e.g. in a non-vacuum environment. The release layer may be made from a solution based polyester resin.

[0020] In embodiments, the roll with the supporting substrate may be provided with a release layer and optionally a lacquer layer coated to the supporting substrate. The release layer and/or the lacquer layer may be coated above the supporting substrate, such as directly on top of the release layer, in a non-vacuum environment. In other embodiments, the coating of the supporting substrate with at least one of the release layer and the lacquer layer may be performed in a vacuum, such as in the vacuum chamber as disclosed herein.

[0021] As used herein, the release layer may be an intermediate layer of a layer stack allowing for separating the one or more layers above the release layer from the one or more layers below the release layer. This is typically done in a controlled environment, such as by exerting heat and/or pressure. The release layer may remain with one or the other separated layer stack. In embodiments of the present disclosure, the release layer remains with the second layer stack.

[0022] The release layer as disclosed herein may, further to the functionality to enable the separation as described, function as a lacquer layer. The release layer may be the lacquer layer as described herein. In particular, the release layer may be a protective layer for the vacuum deposited material. The release layer may in particular be a barrier layer. Although in the following description the release layer and the lacquer layer are mostly described as two separate layers, it is understood that the release layer and the lacquer layer are the same layer in typical embodiments of the present disclosure. [0023] Where provided, the lacquer layer may be made from a resin, such as nitrocellulose, vinyl chloride, vinyl acetate and related copolymers, and a solvent, such as alkanol, alkyl acetate, and alkyl ketone.

[0024] Processing as understood herein particularly includes deposition of a vacuum deposited layer on the supporting substrate, such as deposition of the vacuum deposited layer above, or directly on, the release layer. In embodiments, the vacuum deposited layer is a metallization layer and is in particular selected from the group consisting of aluminum, aluminum oxide (AlOx), and silicon oxide (SiOx).

[0025] The apparatus performing this task may include a deposition drum coupled to a transport system for moving the release layer along a transportation path, wherein at least a portion of the release layer is processed while the supporting substrate, along with possible further layers coated thereon, is guided on the deposition drum. A so-called roll-to-roll (R2R) coating system, which allows for the coating while the supporting substrate is moved on the guiding surface of a deposition drum, can provide a high throughput. [0026] An evaporation process, such as a thermal evaporation process, a PVD (physical vapor deposition) process and/or a CVD (chemical vapor deposition) process can be utilized for depositing a layer of coating material on the release layer or lacquer layer. Herein, this layer is typically referred to as a metallization layer. The deposition device may be adapted for coating the substrate with a particular coating material while the substrate is moved past the deposition device by a transport system, e.g. a roller assembly. The deposition may result in a layer thickness of smaller than 1 micron, in particular of less than 0.8 microns or even less than 0.5 microns.

[0027] According to an aspect of the present disclosure, an apparatus for manufacturing a food packaging material is provided. FIG.s 1 and 2 illustrate an embodiment of such an apparatus according to the present disclosure. [0028] As shown, within the vacuum chamber 130, the composite of supporting substrate 100, the release layer 101 and, if present, an additional lacquer layer 102 is guided over a coating drum 150. The composite is coated with a vacuum deposited layer 103 by the deposition device 160. The vacuum deposited layer 103 may in particular be a metallization layer, consisting of, or including, Aluminum. The composite of supporting substrate, release layer, additional lacquer layer (if any) and vacuum deposited layer is subsequently provided with a top coat layer 104 by the top coat layer applicator 170. The first layer stack 111 is produced.

[0029] In general, and not limited to any embodiment described herein, the top coat layer may be printed. The ink used for the printing may be an acrylate-based composition that has superior properties for printing a top coat layer in vacuum in the context of the present disclosure. In particular, the top coat layer is beneficial in protecting the vacuum deposited layer in the course of further handling of the composite. According to embodiments, the top coat layer is coated above, in particular directly on, the vacuum deposited layer.

[0030] Further, a bio-degradable material 201 is provided. In embodiments, the bio-degradable material 201 is provided outside the vacuum chamber 130 in a non-vacuum environment 200. For instance, the bio-degradable material may be a web, such as a cellulose based web, in particular a paper web. The bonding agent applicator 230 applies a bonding agent, such as an adhesive, to the bio-degradable material 201 and/or the first layer stack 111. The bonding agent applicator is typically positioned in a non-vacuum environment. Subsequently, the bio-degradable material 201 and the first layer stack 111 are bonded together. Bonding may include the activation of the bonding agent by the exertion of pressure and/or heat onto the bonding agent.

[0031] As illustrated in FIG. 2 but not limited thereto, the bonding may be assisted by one or more pinch rollers 260. In embodiments, the one or more pinch roller 260 exert a pressure on at least one of the first layer stack and the bio-degradable material. In particular, the first layer stack and the bio-degradable material may be sandwiched by a pair of pinch rollers 260 so as to perform the bonding.

[0032] After the bonding (as exemplarily illustrated in FIG. 2), the supporting substrate 100 is removed from the layer stack by activation of the release layer 101, resulting in the production of the second layer stack 112. This sequence is beneficial in that the vacuum deposited layer remains sandwiched, and thus protected, between the top coat layer and the supporting substrate during the activity of bonding. In other embodiments, the supporting substrate 100 is removed from the layer stack before or at the same time as the activation of the release layer 101, resulting in the production of the second layer stack 112.

[0033] In FIG. 2, an exemplary release layer activator 240 is illustrated. For instance, the release layer activator may exercise heat and/or pressure on the first layer stack 111. Thereby, the release layer allows for the separation of the supporting substrate 100 from the rest of the layer stack, which ultimately results in the production of the second layer stack 112. In typical embodiments, the activated release layer remains on the second layer stack 112.

[0034] As described, the activities of providing the bio-degradable material 201, bonding the first layer stack to the bio-degradable material and removing the supporting substrate from the first layer stack may particularly be performed in a non-vacuum environment. Likewise, the apparatus of the present disclosure may provide the first guide 210 for providing a bio-degradable material 201, the bonding agent applicator 230, and the second guide 220 for collecting the supporting substrate 100 in a non-vacuum environment. In embodiments, the apparatus further includes a release layer activator, in particular in the non-vacuum environment, for activating the release layer and causing the vacuum deposited layer and the top coat layer to separate from the supporting substrate.

[0035] According to embodiments, an adhesive on the bio-degradable material and/or the first layer stack is provided. Bonding the first layer stack to the bio-degradable material optionally includes bonding the top coat layer to the bio-degradable material. This can be done in a non vacuum environment.

[0036] A “non-vacuum environment” as understood herein can particularly be an environment under atmospheric pressure. A “non-vacuum environment” as understood herein can also include a non-clean room environment.

[0037] FIGs. 3 and 4 illustrate the possible actions as explained in relation to FIGs. 1 and 2 in view of an embodiment of the processed layer stack. With reference to FIG. 3a) and FIG. 4a), an embodiment of the first layer stack 111 is shown, including, from bottom to top, the supporting substrate 100, the release layer 101 functioning also as a lacquer layer, the vacuum deposited layer 103, and the top coat layer 104. As explained, at least the coating with the vacuum deposited layer 103 and the subsequent provision of the top coat layer by e.g. printing or laminating is done in a vacuum environment, such as in the vacuum chamber as described herein.

[0038] Generally, and not limited to any embodiment, the supporting substrate may be a flexible substrate, such as a foil or web, in particular a polymeric foil. Typically, the supporting substrate does not form part of the completed food packaging product. The release layer as understood herein is any material above the supporting substrate that allows for the controlled separation of the supporting substrate from the layers which are above the release layer. Above the release layer is in particular the vacuum deposited layer and the top coat layer. Further layers may be present, in particular, a further lacquer layer may be present. Coating the supporting substrate with the release layer and/or an additional lacquer layer may be done outside a vacuum environment, but also in a vacuum environment.

[0039] The release layer may have a thickness of less than 50 microns, less than 8 microns, or even less than 5 microns. The release may be controlled by the exertion of heat and/or pressure. As exemplarily described previously, the apparatus of the present disclosure may include a release layer activator, typically located in the non-vacuum environment, to exert heat and/or pressure. Once released, the supporting substrate can be collected, e.g. on a supporting substrate drum. The supporting substrate drum is typically provided in a non-vacuum environment.

[0040] After the completion of the first layer stack 111 in a vacuum environment, the first layer stack 111 is bonded to the bio-degradable material 201. This is regularly done outside the vacuum environment. Thus, neither the bio-degradable material nor the bonding agent can reduce the vacuum quality. In order to do so, a bonding agent 202 may be distributed on the bio-degradable material 201 as it is illustrated in FIG. 3b). Alternatively, the bonding agent may be distributed on the first layer stack 111 as it is illustrated in FIG. 4b).

[0041] The bonding agent 202 typically forms a layer as illustrated in FIG. 3b) and FIG. 4b). Hereupon, the first layer stack is bonded to the bio-degradable material. At this stage of the process, the layer stack may include the supporting substrate, the release layer, possibly further layers such as another lacquer layer, the vacuum deposited layer, the top coat layer, the bonding agent, and the bio-degradable material. Further layers may be included according to the specific process design as needed.

[0042] Finally, FIG. 3c) and FIG. 4c) illustrate the layer stack after the further release activity. During this release, the supporting material 100 is separated from the rest by activation of the release layer 101. The supporting material 100 may, for instance, be rolled up on a supporting substrate drum. The supporting substrate may be re-used again. The remaining second layer stack 112, including the bio-degradable material 201, the bonding agent 202 (exemplarily shown as layer in the Figure), the top coat layer 104, and the vacuum deposited layer 103, as well as possibly the release layer 101 and/or further lacquer layers can be used as food packaging material. As illustrated in FIGs. 3c) und 4c), the release layer 101 is the outermost layer. In such a situation, it is recommendable that the release layer, further to being able to allow for the separation from the supporting substrate, has the property of a protective layer.

[0043] In embodiments, methods and apparatuses of the present disclosure further include one or more of the following: Printing, laminating and/or coating the food packaging material. All these activities are typically performed outside a vacuum environment. The vacuum deposited layer is sandwiched and protected for these activities as described.

[0044] According to embodiments, the second layer stack has a very low level of polymeric material such as a level of polymeric material of less than 10 wt%, in particular less than 6 wt%, in particular, in particular the second layer stack may be substantially free of any plastic material. According to embodiments, the finished food packaging material produced according to the present disclosure finished food packaging material has a level of polymeric material of less than 10 wt%, in particular less than 6 wt%, in particular, the food packaging material may be free of any plastic

[0045] By providing the deposition device and the top coat layer applicator within the same vacuum chamber, potential defects in the at least one deposited layer, in particular the metallization layer, which result in a reduced quality of the resulting composite film, are reduced or avoided. Particularly, the layer stack with the exposed vacuum deposited layer is not transported out of the vacuum chamber. Thus, potentially damaging contact between the metallized layer and a transport roller or gate valve is avoided.

[0046] The at least one top coat layer may be coated or laminated over the vacuum deposited layer, such as the metallized layer, directly after the metallization layer is formed, so that the metallized layer is protected from damage. In other embodiments, the at least one top coat layer may be coated or laminated over the vacuum deposited layer after the vacuum deposited layer and a subsequent further layer is formed. In this embodiment the vacuum deposited layer is likewise protected from damage. Further, the exposed vacuum deposited layer is not subjected to a different processing environment prior to being protected by the top coat layer, which avoids oxidation of the exposed vacuum deposited layer. This is particularly advantageous if the vacuum deposited layer is a metallization layer, such as an aluminum layer. As such, the apparatus and method according to aspects of the present disclosure allow for the manufacture of a first layer stack high in quality and robust enough for further handling that can be done in a non-vacuum environment. [0047] The term “film” or “substrate” as used herein shall particularly embrace flexible substrates such as a plastic film, a web, a foil, or a strip. It is noted that a film or substrate as used within the embodiments described herein is typically bendable. The term “film” or “flexible substrate” or “composite” may be synonymously used with the term “foil” or the term “web”. In particular, it is to be understood that some embodiments of the apparatus described herein can be utilized for coating any kind of flexible substrate, e.g. for manufacturing flat coatings with a uniform thickness, or for manufacturing coating patterns or coating structures in a predetermined shape on the film or on top of an underlying coating structure.

[0048] The term “composite” as used herein shall particularly embrace a structure which includes a plurality of layers, deposited material layers and/or printed material layers joined in a manner to produce a layered product.

[0049] The apparatus and method according to aspects of the present disclosure may be configured for manufacturing a food packaging material with a length of 500 m or more, 1000 m or more. The width of the supporting material and/or the bio-degradable material may be 300 mm or more, 500 mm or more, or 1 m or more. The width of the supporting material and/or the bio-degradable material may be 5 m or less, particularly 2 m or less. As explained already and not limited to any embodiment, the bio-degradable material may specifically be a cellulose-based material such as paper. For the present disclosure, the cellulose based material such as the paper may be provided as a web that may have sizes as indicated in this paragraph.

[0050] Typically, the thickness of

- the supporting material may be at least 5 microns and/or not larger than 25 microns;

- the release layer may be at least 1 g/m ² and/or not larger than 12 g/m ² ;

- the lacquer layer may be at least 1 g/m ² and/or not larger than 12 g/m ² ;

- the vacuum deposited layer may be at least 5 nm and/or not larger than 500 nm;

- the top coat layer may be at least 50 nm and/or not larger than 5 microns;

- the paper may be at least 25 g/m ² and/or not larger than 120 g/m ² ; and/or

- the adhesive layer may be at least 1 g/m ² and/or not larger than 8 g/m ² . [0051] The apparatus and method according to aspects of the present disclosure are used for the manufacture of a composite film for food packaging. In this application, the at least one deposited vacuum deposited layer may be surrounded by one or more barrier layers to reduce the permeation/diffusion rates for gases such as oxygen, carbon dioxide and water vapor. A barrier layer aims at increasing the barrier by making a more difficult path for oxygen and water molecules to travel through the layer, and by protecting the vacuum deposited layer from mechanical and environmental damage

[0052] By avoiding damage to the one or more vacuum deposited layers, the performance of the vacuum deposited layers is improved, leading to improved shelf life of products packaged in the composite film, and the quality of the packaged food can be maintained over a longer period of time. The barrier properties of the composite film may depend on the type and thickness of the films as well as on the type and thickness of the barrier layers deposited thereon.

[0053] The quality of the resulting layer stack may further depend on the cleanliness of the surface of the supporting substrate, the release layer, and/or the lacquer layer before deposition of the one or more deposited layers in the vacuum chamber. Debris and small particles may be present before coating. These particles may be coated with the deposited layer and may later be mechanically removed by contact with rollers of the apparatus. At the positions of these defects, the compound film may not include the deposited layer, resulting in a composite film with, for example, reduced gas barrier performance or reduced aesthetic quality.

[0054] In the present disclosure, a “deposition device” may be understood as an apparatus configured for depositing material on a substrate. For example, the deposition device 160 may be a physical vapor deposition (PVD) apparatus, chemical vapor deposition (CVD) apparatus, evaporation deposition apparatus, or another deposition apparatus known in the art. The deposition device may include an evaporator for evaporating material or a crucible. The deposition process may include sputtering, plasma enhanced evaporation, and/or e-beam evaporation. Herein, bonding or laminating a layer to another layer is not understood as depositing the layer.

[0055] In the present disclosure, the deposition drum, can be understood as a drum or a roller having a substrate support surface for contacting the supporting substrate. In particular, the deposition drum may be rotatable about a rotation axis and may include a film guiding region. Typically, the film guiding region is a curved film support surface, e.g. a cylindrically symmetric surface, of the deposition drum. The curved film support surface of the deposition drum may be adapted to be (at least partly) in contact with the supporting substrate during operation of the deposition device. The deposition drum may be heated or cooled depending on the material to be deposited.

[0056] The apparatus for producing food packaging material exemplarily shown in the figures includes a deposition drum 150, however, the present disclosure is not limited thereto. For example, the substrate support along with the release layer and optionally a lacquer layer may be transported past the at least one deposition device 160 by spanning between two rollers.

[0057] FIG. 5 illustrates another example of parts of the apparatus according to the present disclosure. As exemplarily illustrated, the vacuum chamber 130 for producing the first layer stack 111 may include one or more guide rollers. At least one roller may be an active roller with a drive or motor for rotating the roller. In some arrangements, more than one active roller may be provided. An “active” roller or roll as used herein may be understood as a roller that is provided with a drive or a motor for actively moving or rotating the respective roller. For example, an active roller may be adjusted to provide a predetermined torque. Active rollers can be configured as substrate tensioning rollers configured for tensioning the substrate with a predetermined tensioning force during operation. Generally, and not limited to the embodiment of Fig. 5, at least one of the unwinding spool 501, the deposition drum 160 and/or the rewinding spool 502 may be active rollers.

[0058] At least one roller may be a passive roller. In some arrangements, more than one passive roller may be provided. A “passive” roller as used herein may be understood as a roller or roll that is not provided with a drive for actively moving or rotating the passive roller. The passive roller may be rotated by the frictional force of the foil that may be in direct contact with an outer roller surface during operation.

[0059] However, in embodiments that can be combined with all other embodiments described herein, no guide roller is positioned along the transport path for the composite between the deposition device 160 and the top coat layer applicator 170. This is also illustrated in FIG. 5 in which, after the deposition device 160, the composite is transported without any further contact to a guide roller to the top coat layer applicator by which the further top coat layer is applied on top of the vacuum deposited layer. Note that this limitation does not exclude a roller or rollers being provided between the deposition device 160 and the top coat layer applicator 170 which contact the non-coated surface of the vacuum deposited composite.

[0060] In addition or alternatively, in embodiments of the present disclosure, no guide roller is provided until the top coat layer is sufficiently hardened. This is also illustrated in FIG. 5 in which the composite, after the top coat layer applicator, is forwarded to an e-cure station 524 without any contact to a guide roller during that transport. Note that this limitation does not exclude a roller or rollers being provided between the top coat layer applicator 170 and the e-cure station 524 which contact the non-coated surface of the vacuum deposited composite.

[0061] Not limited to the embodiment of, but merely illustrated in relation to, FIG. 5, the vacuum chamber 130 may include a support for an unwind spool 501 and/or a support for a rewind spool 502. The unwind spool 501 may be a roll with the supporting substrate 100 that may further include the release layer 101. The rewind spool 502 is supposed to collect the freshly produced first layer stack 111 in which the vacuum deposited layer, such as the metallization layer, is well protected, namely sandwiched between the supporting substrate 100 and the top coat layer 104. Sandwiched in this context includes the possibility that further layers are present. For instance, an additional lacquer layer 102 may be present between the supporting substrate 100 and the top coat layer 104. The additional lacquer layer may be between the vacuum deposited layer and the supporting substrate. More specifically, the additional lacquer layer may be between the vacuum deposited layer and the release layer.

[0062] The composite may be unspooled from unwind spool 501 and directed towards the deposition device 160 during operation of the apparatus. Between the support for the unwind spool 501 and deposition device 160 several further elements may be provided on the path of the composite. For instance, a pre-treater 530 may be provided. A pre-treater as understood herein may treat the substrate laminate before the vacuum deposition. Accordingly, in the method according to embodiments disclosed herein, pre-treatment of the substrate laminate may forego the vacuum deposition of the vacuum deposited layer. For instance, the pre-treatment may include cleaning and/or heating the composite; both activities can positively influence the deposition process. One or more guide rollers, such as guide roller 511, 512, and 513 illustrated in FIG. 5, may be provided before and/or after the pre-treater 530. [0063] The top coat layer applicator 170 as understood herein may in particular be a printing station. A printing station may include a reservoir 521 for receiving ink and/or an inking roller 522 for collecting ink (e.g. from the ink reservoir 521) and transferring the ink to an applicator roller 523. The applicator roller 523, in this example, receives the ink from the inking roller 522 and applies the ink to the composite, typically directly on top of the vacuum deposited layer 103. This is also illustrated in FIG. 5. However, in other embodiments, one or more further layers may be provided or deposited on top of the vacuum deposited layer before the top coat layer is coated thereto.

[0064] In embodiments, the ink is an unsaturated component consisting essentially of an unsaturated acrylate monomer, or a combination of an unsaturated acrylate monomer and an unsaturated acrylate oligomer and precursor, the unsaturated component of which is polymerizable or crosslinkable by the application of electron beam radiation, wherein the ink is substantially absent of unsaturated acrylate components, substantially absent of polymerization initiators, and substantially absent of solvents. Alternatively, the ink may include a first component which is polymerizable or crosslinkable in the presence of an acid; and a cationic photoinitiator which generates a sufficient amount of an acid upon exposure to sufficient ultraviolet radiation, electron beam radiation, plasma radiation or combinations of two or more of ultraviolet radiation, electron beam radiation and plasma radiation, to cause polymerizing or crosslinking of the first component.

[0065] In embodiments, an after-coating treatment of the top coat layer is performed. The after- coating treatment may in particular dry and/or harden the coated top coat layer. As illustrated in FIG. 5, the after-coating treatment may include an after-treatment drum 520 over which the composite is guided. The after-coating treatment may include an e-cure station 525. In the e-cure station 525, the printed ink may be exposed to electron beam radiation. As shown, it is possible that several e-cure stations 525 are provided. As this is done within the vacuum chamber, and thus in a substantially oxygen-free atmosphere, the ink composition is polymerized and/or crosslinked. Reference number 524 illustrates further elements of the e-cure station 525, such as a vacuum insulation part or a shield.

[0066] As illustrated in FIG. 5, but not limited thereto, one or more further guide rollers 514, 515 and 516 may be provided between the top coat layer applicator and the rewind support for the rewind spool 502. [0067] In embodiments, the process is carried on until the complete composite from unwind spool 501 is used up and collected in the rewind spool 502. At this stage, the composite on the rewind spool corresponds to the first layer stack 111. Typically, once the roll is completed, the rewind spool 502 is taken out of the vacuum chamber 130 and provided to the further processing activities as disclosed herein outside the vacuum environment. For this reason, as one possible embodiment, the roll providing the first layer stack 111 in FIG. 2 is denoted with the reference number 502. The further processing activities particularly include providing a bio-degradable material, bonding the first layer stack to the bio-degradable material; and removing the supporting substrate from the first layer stack.

[0068] During guidance of the supporting substrate by the deposition drum past the deposition device, the supporting substrate may be in direct contact with the substrate support surface of the deposition drum. As the deposition drum rotates, the composite is guided past the deposition device which faces toward the curved film support surface of the deposition drum, so that the vacuum deposited layer can be coated while being moved past the deposition device at a predetermined speed.

[0069] The deposition device may include a deposition source configured for providing a material to be deposited. For example, the deposition device may include a sputter source or an evaporation source. In embodiments, the deposition device may include a plurality of deposition stations. In some embodiments, two or more of the deposition stations are configured to deposit the same material. For instance, if a metallic layer is deposited, and the metallization is performed with Aluminum, two or more deposition stations of the deposition device may include a source for Aluminum deposition.

[0070] The vacuum chamber is at a pressure below atmospheric pressure. For instance, the apparatus for the production of food packaging material may include components and equipment allowing for generating or maintaining a vacuum in the vacuum chamber. The apparatus may include vacuum pumps, evacuation ducts, vacuum seals and the like for generating or maintaining the vacuum in the vacuum chamber. For instance, the vacuum chamber 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. [0071] The term “vacuum”, as used herein, can be understood in the sense of a technical vacuum having a vacuum pressure of less than, for example, 10 mbar. Typically, the pressure in a vacuum chamber as described herein may be between 10 ⁵ mbar and about 10 ⁸ mbar, more typically between 10 ⁵ mbar and 10 ⁷ mbar, and even more typically between about 10 ⁶ mbar and about 10 ⁷ mbar. A non-vacuum environment as understood herein refers to an environment that is typically under atmospheric pressure, however, in certain embodiments underpressure of up to 10 ² mbar or even 10 ³ mbar is understood as a non-vacuum environment.

[0072] FIG. 6 shows a schematic view of the vacuum chamber of an apparatus producing a food packaging material according to embodiments described herein.

[0073] According to an embodiment, which may be combined with other embodiments described herein, the apparatus may include a support for the unwinding spool 501 provided upstream of the deposition apparatus 200, the unwinding spool 501 being configured for unwinding the supporting substrate. Further unwinding spools may be provided. As illustrated, at least one lamination unwinding spool 412, 413 may be provided upstream of a laminating apparatus. The at least one lamination unwinding spool 412, 413 may be configured for unwinding at least the top coat layer 104. Additionally, the at least one lamination unwinding spool may be configured for unwinding a connection layer 108 that connects the top coat layer 104 with the metallization layer 103. For instance, the connection layer 108 may be glue. The connection is typically performed in the top coat layer applicator 170, which is, in this embodiment, a laminating apparatus. The laminating apparatus is configured to suitably activate the connection layer 108 so that the connection layer causes a connection between the vacuum deposited layer and the top coat layer under vacuum conditions.

[0074] The deposition device 160 as exemplarily shown in FIG. 2 includes a deposition drum 150 and a plurality of deposition stations 161, 162, 163, 164, 165 and 166. The plurality of deposition stations may be provided around the circumference of the deposition drum 150. For instance, the deposition device may include at least three or at least four deposition stations. For example, the deposition device may include a plurality of sputter sources and/or a plurality of evaporation sources. The modular design of the deposition device facilitates replacing deposition stations 161 to 166 by radially removing a deposition station and loading another deposition station into the deposition device.

[0075] According to embodiments that can be combined with other embodiments, gas separation walls may be provided between two adj acent deposition stations in order to reduce a flow of process gases from one deposition station to another deposition station, e.g. to an adjacent deposition station during operation, respectively. Accordingly, a high gas separation between neighboring deposition stations can be provided beneficially.

[0076] The terms “upstream of’ and “downstream of’ as used herein may refer to the position of the respective component with respect to another component along a film transportation path.

[0077] The apparatus and methods of the present disclosure may be configured to guide the respective foils at a speed of 1 m/s or more, particularly 5 m/s or more, more particularly 10 m/s or more, or even 15 m/s or more.

[0078] As described, but not limited to the illustrated figures, a roll-to-roll (R2R) coating system may be provided inside the vacuum chamber for producing the first layer stack. In embodiments, a roll is provided that includes a composite foil of supporting substrate together with a release layer coated above the supporting substrate and optionally a lacquer layer. Further layers may be included in the composite.

[0079] A roll-to-roll bonding system may be provided for performing the activities of providing a bio-degradable material, bonding the first layer stack to the bio-degradable material; and removing the supporting substrate from the first layer stack. In embodiments, the roll-to-roll bonding system is provided in a non-vacuum environment.

[0080] The guiding speed of the processing may be determined by an active roller, also referred to as the “master roller”, which may be preset to rotate at a predetermined rotation speed. One or more further active rollers may be tension-controlled rollers such that the tension of the substrate can be controlled as appropriate and an extensive or an insufficient substrate tension can be avoided. In other arrangements, e.g. in an apparatus configured for sputter deposition of the vacuum deposited layer, the transport system may be configured for a lower guiding speed of the film, e.g. a guiding speed of 10 m/min or less. [0081] In embodiments, the first layer stack and the second layer stack are produced asynchronously. This can be understood as follows. In a first activity, a roll of composite foil having the first layer stack is produced in a vacuum environment. This roll is subsequently taken out of the vacuum. Subsequently, the roll with the first layer stack is bonded to the bio-degradable material as described herein in a non-vacuum environment, such as in atmospheric pressure. At the same time the bonding process happens, the coating chamber can be used to coat the composite foil including the first layer stack that is collected by another roll.

[0082] Still with reference to FIG. 6, according to an embodiment, which may be combined with other embodiments described herein, at least one of the winding spool 501, the at least one laminate unwinding spool 112, 113, and the rewinding spool 501 may be provided in at least one spool chamber 401, 402, 403, 404 respectively. For example, first unwinding spool 501 which is configured for unwinding the supporting substrate may be provided in a first winding spool chamber 401 which is separate from the vacuum chamber 130. Similarly, the at least one laminate winding spool 412, 413 which is configured for unwinding the at least one connection layer 108 and the top coat layer 104 may be provided in a respective second winding spool chamber 402, 403. Additionally or alternatively, the unwinding spool 502 which is configured for winding the foil with the deposited first layer stack 111 may be provided in a rewinding spool chamber 404.

[0083] The respective spool chambers 401, 402, 403, 404 may be provided with gate valves 401a, 402a, 403a, 404a arranged at a wall of vacuum chamber 130 to allow for a respective film to be transported into and out of the vacuum chamber 400. Particularly, the gate valves 401a, 402a, 403a, 404a include a sealing device such that the respective spool chamber 401, 402, 403, 404 can be vented, while the vacuum chamber 400 may be maintained in an evacuated state. Providing the unwinding and winding spools within separate spool chambers facilitates quick and efficient loading and unloading of the respective spools, without venting the vacuum chamber 130. Due to the comparative robustness of the top coat layer 104, the connection layer 108, and the produced layer stack 111 in comparison to the fragile exposed vacuum deposited layer 104, the respective films may pass through the respective gate valves with no or negligible damage which has no effect on the quality of the resulting composite film. [0084] Alternatively, the quality of the layer stack 111 may be further improved by avoiding any contact between a respective film and a gate valve. For example, and not limited to any embodiment, at least one of the unwinding spool 501, the at least one laminate unwinding spool 112, 113, and the rewinding spool 502 may be provided in the same vacuum chamber 130 as the deposition device 160 and the top coat layer applicator 170. Such an arrangement allows for the respective films to be transported through the apparatus without passing through a vacuum chamber gate valve, reducing the occurrence of scratching, rubbing or marring of the surfaces of the respective films prior to deposition, prior to lamination or after lamination. It follows that the quality of the resulting composite film is further improved.

[0085] According to an embodiment, which may be combined with other embodiments described herein, the laminating apparatus may include a thermal laminating apparatus. For example, the laminating apparatus may include heating elements configured to heat the stack of layers such that the layers are thermally joined to each other. The heating elements may include a non-contact heating element, e.g. an infrared heating element, or may include a contact heating element, e.g. a heated roller. Particularly, pinch rollers may be provided to apply additionally pressure. In embodiments, the pinch rollers are heated pinch rollers.

[0086] According to a further aspect described herein, a method for manufacturing a food packaging product is provided. As diagrammatically shown in FIG. 7, the method includes providing a supporting substrate 700, providing a release layer 701 that in some embodiments is a lacquer layer at the same time, coating the lacquer layer with a metallization layer 702, and providing a top coat layer 703, in a vacuum environment. In embodiments, the method may include the provision, in particular the deposition of, additional layers in the vacuum environment. In particular, the method may include providing an additional lacquer layer.

[0087] The method further includes, in particular in a non-vacuum environment, providing a bio degradable material 705; bonding the first layer stack to the bio-degradable material 706; and removing the release layer from the first stack 707. In embodiments, the method may include the provision, in particular the lamination of, additional layers in the non-vacuum environment. [0088] 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.