Transparent cellulose packaging

Abstract

The present invention relates to a three-dimensional food package (100). The three-dimensional food package (100) is made of a cellulosic fibrous material (200) and defines a package interior (V). At least a portion (111) of the three-dimensional food package (100) that bounds at least a portion of the package interior (V) is impregnated with a polymer (300), such that the impregnated portion (111) of the polymer (300) has a light transmittance of greater than 60% for visible light.

Description

[Technical field]

[0001] The present invention relates to food packaging made from fibrous cellulosic materials that have a high level of transparency. [Background technology]

[0002] In the field of packaging, packages made of cellulosic pulp, such as paper or cardboard, or made by forming a cellulosic slurry, are known for packaging edible products for human or animal consumption. It is also known in the field that such cellulosic materials can be chemically or mechanically treated, or combined with other materials, to provide the package with barrier properties, such as a barrier against liquids, moisture, or oxygen, to ensure that the quality of the packaged product is maintained over a period of time.

[0003] Cellulosic materials can be produced, for example, from wood. Wood cannot be used as is to form packaging, but can be transformed through a series of chemical and mechanical treatments in which undesirable wood components such as lignin are removed to obtain a cellulosic material that can then be converted into packaging. Because cellulosic packaging can be produced from renewable resources, these cellulosic packaging have a reduced environmental impact compared to packaging made from other materials such as petroleum-based plastics currently used in packaging, and recycling processes for such materials are available, well known, and cost-effective in most countries.

[0004] However, a drawback of cellulose materials such as paper, cardboard, or moldable cellulose pulp is their lack of transparency. This is particularly problematic in the packaging of edible products, because consumers want to visually control the type, quantity, and quality of the product in the package without having to open the package for that purpose. In addition, the transparency of the package can also be used to ripen fruits or vegetables in the package, or to activate the release of flavors, aromas, or fragrances when exposed to light, such as sunlight.

[0005] As a solution to overcome the lack of transparency of the packaging, cellulosic packaging is often combined with a different transparent material, such as a (petroleum-based) plastic film, to create a see-through window in the package. However, since it is not possible to recycle the cellulose part together with the plastic material, such "hybrid" packaging solutions are generally not suitable for seamless recycling, since either the consumer or the recycling facility needs to separate the different types of components of the packaging. From this, it is clear that the disposal and recycling process of such hybrid packaging solutions can be relatively complicated and costly, and therefore disadvantageous.

[0006] Therefore, in the prior art, attempts have been made to treat cellulosic materials to achieve a level of transparency. To this end, relatively thin layers of paper, e.g. 30 g / m 2 Chemical treatments had to be applied to papers with basis weights of 1000 gsm or less. However, none of the prior art attempts have resulted in a material with transparency. Instead, only translucency has been achieved, but unlike transparency, the product can only be distinguished through the package wall, and the visual display of the product remains unclear and indistinct. Transparency, in contrast, refers to the optical clarity that allows objects to be seen when looking through the material.

[0007] Thus, the translucent paper still lacks transparency since most of the light passing through the paper is blocked or randomly scattered, resulting in a lack of visual definition and a blurred appearance of the packaged item.Furthermore, although a relatively thin thickness of the paper material may be usable in some specific packaging applications, such as overwrapping individual candies or chocolates, for most food packaging purposes, such thickness has been found to pose some challenges due to the relatively low elongation at break and lack of mechanical resistance of the material, as well as increasing the complexity of packaging food products mechanically.

[0008] Further attempts have been made, for example by Feixiang Guan et al. in the Journal of Bioresources and Bioproducts (volume 5, issue 1, February 2020, Pages 37-43), where conventional paper has been chemically treated to achieve a transmittance of over 90% at 550 nm. Although the results obtained are promising in terms of transparency, it is not feasible to bring the required chemical treatment into contact with edible products due to the high toxicity of the chemicals required. Instead, the resulting paper is intended to serve as an alternative substrate in the manufacture of flexible electronics. Thus, the challenge of providing recyclable food packaging with a certain level of transparency remains unsolved.

[0009] It is therefore an object of the present invention to provide packaging from cellulosic fibers that has a high level of transparency, is safe for use with food, can be made sufficiently rigid or stretchable (until breakage) to allow machine production of rigid and flexible packages (e.g. trays or pouches) from such fibers, and is recyclable in paper processing. Advantageously, the packaging can be provided with barrier properties against the transfer of oxygen, grease, and / or moisture.

[0010] These and other objects which become apparent on reading the description are solved by the subject matter of the independent claims. The dependent claims refer to preferred embodiments of the invention. Summary of the Invention

[0011] One aspect of the present invention relates to a three-dimensional food package. The food package is made of a cellulosic fibrous material. The food package defines a package interior. At least a portion of the food package that defines at least a portion of the package interior is impregnated with a polymer, such that the impregnated portion has a (direct) light transmittance of greater than 60% for visible light.

[0012] The packaging may, for example, form an outer shell for storing a food product therein and allow the food product to be enclosed within a package, container, capsule, pouch, or wrapping that may extend in all three dimensions (preferably such that its extension in each dimension may be significant relative to the others). For example, the packaging may be a voluminous body (rather than extending primarily in a single plane). As a food packaging, the packaging may be designed to be safe for direct contact with food products.

[0013] This food packaging therefore allows for the provision of free space within the food packaging (hidden from the outside by the packaging) which allows food to be contained and safely stored throughout the intended shelf life of the product.

[0014] By preparing food packaging from cellulosic fibrous material, i.e. material that may comprise, consist of or resemble fibers and / or be separable into fibers and that may comprise and / or be made from cellulose, it is possible, for example, to produce food packaging from (only) sustainable sources and to recycle (for example EN 13430 standard) or even compost (for example EN 13432 standard) the food packaging (in its entirety) after its use. Furthermore, the mechanical strength and stiffness of the food packaging can be adapted to the application, for example by adapting the parameters of the cellulosic fibrous material.

[0015] Impregnating a section or part of a food packaging, for example, which may form part of a shell surrounding the inside of the packaging, with a polymer allows the introduction and incorporation of a certain amount of substance into the cellulosic fibrous material to adapt the material properties of the food packaging. For example, in the impregnation process, the polymer may be transported into the gaps between the fibers of the cellulosic fibrous material, and thereby absorbed by the cellulosic fibrous material. The polymer can thus change the properties of the impregnated part. For example, the polymer can be used to modify the light scattering behavior of the cellulosic fibrous material of the food packaging, such as the behavior regarding transparency (for example, related to optical clarity, measured as the percentage of light that deviates from the incident light beam by less than 2.5 degrees when passing through the material), haze (for example, related to contrast, measured as the percentage of light that deviates from the incident light beam by more than 2.5 degrees when passing through the material), and transmittance (for example, related to light intensity).

[0016] In particular, that portion of the food packaging is impregnated with a polymer such that such impregnated portion has a (direct) luminous / light transmittance of greater than 60% (e.g., is impregnated in such a manner, process, to such an extent, and / or with such results).

[0017] Here, the (direct) light transmittance is determined as the ratio of the amount of light energy (light flux) emitted by the light source and incident on the impregnated part that passes through the material of the impregnated part without being scattered or only negligibly (e.g. at an angle of less than 2.5 degrees) to the amount of light energy (light flux) emitted by the light source and incident on the impregnated part, and is expressed as a percentage. Preferably, light can pass through the impregnated part regardless of its overall direction of travel. That is, the amount of light that can pass from the inside of the package to the outside of the food package can be the same or at least similar to the amount of light that can pass from the outside of the food package to the inside of the package. Furthermore, the light transmittance value can relate to light that includes light waves having a wavelength spectrum that corresponds to the visible spectrum, i.e. the wavelength spectrum of light visible to the human eye, which can be from 300 nm to 800 nm, preferably from 370 nm to 780 nm.

[0018] It has been found that transparency depends on light passing through a material substantially undeflected, since even slight deflections can impair the visual impression (e.g., as quantified by haze and / or transparency). The inventors have now surprisingly found that by creating food packaging with the claimed level of light transmission in the manner described above, it is possible to provide the food packaging with a transparent portion having a quality that facilitates optically clear viewing of the packaged food inside the packaging from the outside through the material of the food packaging across a wide variety of different food packaging applications (e.g., from coffee capsules to food trays or even water bottles). In comparison, translucent packages known from the prior art do not allow a clear and distinct view of the food through the material. In addition, it has been found that the porosity of the cellulosic fibrous material can be reduced, thereby increasing the diffusion of light, thereby also contributing to the transparency of the food packaging. Thus, the food packaging of the present invention provides a solution to the above-mentioned technical problems present in the prior art.

[0019] According to preferred embodiments, the impregnated portion may have a (direct) light transmission for visible light of more than 65%, more than 70%, more than 75%, more than 80%, more than 85%, more than 90%, more than 95%, or even 100%. Alternatively or additionally, the haze (e.g. corresponding to the (direct) transmission value) may be less than 30%, less than 20%, or less than 10%. Alternatively or additionally, the transparency (e.g. corresponding to the (direct) transmission value) may be more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, or even more than 95%.

[0020] This allows for improved optical clarity by allowing an external view through the food packaging material to view the packaged food inside the package, where it has been found that the levels of light transmission of existing prior art translucent paper materials for food packaging cannot be increased to or beyond the above claimed levels, or that it is economically unfeasible to bring such paper materials to such levels.

[0021] According to a further preferred embodiment, the polymer may be a food grade material. Alternatively or additionally, the polymer may be a bioplastic and / or the polymer may be compostable and / or biodegradable. However, it is also contemplated that the polymer may be a non-biodegradable polymer or a petroleum-derived polymer.

[0022] As used herein, the expression "food grade material" may be understood to mean a material that is safe for human consumption or that is safe for direct (i.e., immediate, unobstructed) contact with food.

[0023] Furthermore, the term "compostable" may be understood to mean that when a material is composted, it can be substantially broken down into organic matter within a few weeks or months. This may be achieved in industrial composting facilities and / or home composters. In such facilities, there may be specific conditions related to wind, sunlight, drainage and other factors. At the end of the composting process, when the material is completely decomposed, it may provide nutrients to the soil. International standards such as EU 13432 or US ASTM D6400 provide the legal framework for specifying the technical requirements and procedures for determining the compostability of materials.

[0024] In comparison, the expression "biodegradable material" may be understood as any material that can be decomposed by (the action of) living organisms (microorganisms, such as bacteria, fungi or algae) into products that are harmless to the environment. This process may take place in an environment in which oxygen is present (aerobic) or in which oxygen is not present (anaerobic).

[0025] Thereby, it is possible to provide the entire food packaging from materials that are not only suitable for food contact but also suitable for composting, thus reducing the ecological footprint of the food packaging.

[0026] According to a preferred embodiment, the polymer may have a similar or identical refractive index to the cellulosic fibrous material. However, it is contemplated that the refractive indices of the two materials may differ from each other. Preferably, the absolute difference between these refractive indices may be less than 30%, less than 20%, or less than 10% of the refractive index of the cellulosic fibrous material.

[0027] Here, the refractive index of a material may be understood as a dimensionless parameter that describes, for example, the speed of light passing through the material. For example, the refractive index of paper may be approximately 1.5.

[0028] This can further increase the degree of transparency of the food packaging since the impregnated portion can be provided only from components having a uniform or at least similar refractive index (as opposed to translucent materials that may contain components with different refractive indexes). In particular, tailoring the refractive index of the polymer to that of the cellulosic fibrous material can provide optimal optical clarity without distortion of light through the food packaging material. In comparison, refractive index differences can reduce optical clarity.

[0029] According to further preferred embodiments, the polymer may comprise a polyolefin, a polyacrylate, a polycaprolactone, a polyester, a polyalcohol, a polyhydroxyalkanoate, a thermoplastic starch, a cellulose derivative, an epoxy resin, or any combination thereof.

[0030] Any of the above polymers can be used to impregnate cellulosic fibrous materials and provide the desired level of transparency for food packaging, particularly as the use of any of these types of polymers may not compromise food safety or the biodegradability or compostability of the food packaging.

[0031] According to a preferred embodiment, the concentration of the polymer that may be contained in the impregnated portion may be continuous or at least partially continuous. Alternatively or additionally, the concentration of the polymer that may be contained in the impregnated portion may vary along at least one of its directions of extension. For example, the concentration of the polymer in the impregnated portion may vary between the inside of the packaging and its opposite side. Preferably, the impregnated portion may comprise 0.5% to 20% by weight of the polymer relative to the weight of the corresponding section of the cellulosic fibrous material. More preferably, the impregnated portion may comprise 1% to 15% by weight of the polymer relative to the weight of the corresponding section of the cellulosic fibrous material.

[0032] It is thereby possible to provide food packaging with different levels of transparency or to alternate between opaque, translucent and transparent sections. In addition to this, it is possible to use locally high concentrations of polymers to provide additional functions such as sealing or barrier functions. Furthermore, this also allows the food packaging material to be converted from flat sheets into three-dimensional packages, for example by forming and sealing the three-dimensional packages.

[0033] According to a further preferred embodiment, the impregnated portion may comprise at least one sealing portion for sealing the impregnated portion. Preferably, the polymer may be suitable for heat and / or ultrasonic sealing. The sealing portion may comprise a concentration of polymer that allows sealing the impregnated portion by heat and / or ultrasonic sealing. The sealing portion may be provided on one side of the impregnated portion and may comprise a higher concentration of polymer than the corresponding opposite side. For example, polyethylene may be used for sealing the impregnated portion.

[0034] Thereby, the food packaging material can be sealed at the side having a locally high concentration of the sealable polymer, sealing the food packaging material to other sealing parts provided in the food packaging or to other elements (e.g. a lid) forming the finished food packaging. Thus, the manufacturing of the food packaging can be simplified and the design freedom of the food packaging can be increased. Furthermore, it has been found that such a configuration can improve the adhesive strength between the sealing parts.

[0035] According to a preferred embodiment, the food packaging may comprise a plurality of impregnated portions. Preferably, at least some of the impregnated portions may be separated from each other by one or more sections of the food packaging, the one or more sections containing a low concentration of polymer compared to the impregnated portion or no polymer at all. Preferably, the impregnated portions may extend throughout the entire food packaging.

[0036] This allows, for example, the food packaging to be provided with multiple windows or one continuous window to view the packaged food from different sides or angles, and in addition, it is also possible to protect light-sensitive parts of the packaged food from light while leaving less sensitive parts of the packaged food exposed.

[0037] According to a further preferred embodiment, the food packaging may comprise an oxygen barrier, a grease barrier and / or a moisture barrier. Alternatively or additionally, at least the impregnated part may comprise an oxygen barrier, a grease barrier and / or a moisture barrier. Preferably, the oxygen barrier is 5 cm thick. 3 / m 2 / day. The moisture barrier may have an oxygen transmission rate (OTR) of less than 5 g / m 2 The composition may have a moisture transmission rate (MVTR) of less than 100 / day.

[0038] Here, OTR can be a measure of the amount of oxygen gas passing through a material over a period of time. For example, OTR can be measured using known methods defined in industry standards such as DIN 53380-3, ASTM D1434, or ISO 2872.

[0039] Additionally, MVTR can be a measure of the transmission of moisture (e.g., water vapor) through a food packaging material. For example, MVTR can be measured using known methods (e.g., gravimetric based) as defined in industry standards such as ISO 2528, ASTM E96, ASTM D1653, or TAPPI T464.

[0040] This allows the food packaging to have the ability to preserve the integrity and quality of the packaged food within the package over its intended shelf life.

[0041] According to preferred embodiments, the food packaging and / or at least the impregnated portion may have a thickness of 5 μm or more, 40 μm or more, 0.1 mm or more, 0.5 mm or more, 1 mm or more, 2 mm or more, 3 mm or more, 4 mm or more, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, 0.5 mm or less, 0.1 mm or less, or 40 μm or less, or the food packaging and / or at least the impregnated portion may have a thickness according to any combination of any of the aforementioned upper and lower limits.

[0042] This allows the food packaging to have the mechanical stability and rigidity required for the particular packaging application without having to compromise or abandon the advantages of having a transparent food packaging. In addition, the thicker food packaging material can provide better barrier properties for the food packaging, which is beneficial for shelf life.

[0043] According to a further preferred embodiment, the impregnated portion may be impregnated in a solid impregnation process.

[0044] Here, a solid impregnation process can be understood as one in which the polymer and the cellulosic fibrous material are each provided as a solid in the impregnation process. For example, the polymer may be provided as a powder, which may preferably have a homogeneous distribution (Gaussian curve distribution) that may vary from 100 nm to several (for example up to 10) μm, and this powder is "forced" into the cellulose matrix of the fibers, for example under the application of a high AC voltage, for example to fill the voids and gaps between the cellulosic fibers.

[0045] It is possible to provide a homogeneously distributed polymer particle in the food packaging. As no solvent is required as opposed to liquid impregnation processes, no traces of solvent are visible inside the food packaging material. Therefore, the level of transparency can be improved and the risk of introducing non-food grade materials into the food packaging is reduced.

[0046] Alternatively or additionally, it is conceivable to use a liquid impregnation process, in which the polymer is dissolved in a solvent such as acetone, chloroform, dichloromethane, etc., and then applied to the cellulosic fibrous material for impregnation. For example, the choice of solvent may vary depending on the type of polymer used. The solvent containing the polymer may thereby be absorbed by the cellulosic fibrous material. Alternatively or additionally, vacuum impregnation may be used.

[0047] According to preferred embodiments, the cellulosic fibrous material may include paper, paperboard, cellulosic pulp suitable for molding, cellulose nanofiber sheet or film, air-laid cellulose and / or delignified wood.

[0048] Thereby, food packaging can be provided from a variety of sustainable, recyclable, biodegradable, compostable and / or food compatible materials, each of which additionally allows for freedom in designing the shape of the food packaging.

[0049] According to further preferred embodiments, the food packaging (e.g. entirely / as a whole) may comprise more than 70% by weight, more than 75% by weight, more than 80% by weight, more than 85% by weight, more than 90% by weight, or more than 95% by weight of cellulose. Alternatively or additionally, the food packaging may be recyclable. For example, the food packaging may be recyclable in a paper recycling process. Alternatively or additionally, the food packaging (as a whole) may be biodegradable.

[0050] Here, the expression "recyclable" can be understood as a material that can be (completely) reused for a new product or new purpose, for example after being mechanically or chemically treated using industrial or natural processes. For example, materials used for food packaging can be collected after use and mixed with water and chemicals to decompose. This is heated and decomposed into strands of cellulose. Plastic coatings and inks can be removed as long as they do not exceed a certain amount. For example, to successfully recycle paper materials, the polymer content in recyclable materials can be only up to about 5% (or preferably up to 20%) of their total weight. Industrial standards such as EN13430, ISO15270 and ISO14001 relate to the requirements laid down for the implementation of industrial recycling.

[0051] In the paper recycling process, the material composition of the food packaging as waste material may undergo a process (such as repulping into fibers) to obtain a material, i.e., recycled material, that can be used for a purpose, such as to make another article (such as a sheet of paper that is not necessarily another food packaging).

[0052] It is thereby possible to provide food packaging that has a high cellulose content which facilitates that the food packaging is biodegradable and / or may be considered particularly suitable for recycling in the paper recycling processes of most countries around the world.

[0053] According to a preferred embodiment, the impregnated portion may form at least one window within the packaging to reveal a food product disposed within the food packaging.

[0054] This allows the consumer to visually control the type, quantity and quality of the food product through a window in the food package without having to open the food package.

[0055] According to a preferred embodiment, the food package may comprise at least one package wall defining a body of the food package. Preferably, the package wall may define a rigid or flexible body of the food package. The body of the food package may define an interior of the package. Preferably, the food package has a density of 30 g / m 2 ~800g / m 2 Alternatively or additionally, at least one package wall, if present, may have a basis weight of 30 g / m 2 ~800g / m 2 The sheet may have a basis weight of 100 g.

[0056] Here, the term "rigidity" may be understood as the ability of a material to withstand an applied mechanical load, for example a load resulting from a food being filled inside the package, or a deformation in response to the gripping force of a user to grasp and carry the filled food package. This ability may preferably result from the compactness of the material of the packaging wall, or may be inherent to the body. For example, the packaging wall may comprise a thickness or density that promotes the material to a certain extent to be mechanically inflexible. In the case of a fiber-based material, for example, the bending stiffness may be determined in a test according to ISO 2493. For example, the rigid body may have a bending stiffness of 400 Nm to 3500 Nm. The rigid body may preferably have a bending stiffness of 30 g / m 2 ~800g / m 2 Preferably, the rigid body has a basis weight of 250 kg / m 3 ~1000kg / m 3However, stiffness may be achieved not only structurally, for example by providing the food package with relatively thick walls or ribs, but also chemically, for example by providing the food package from a particular material or by applying a particular coating or laminate to the food package.

[0057] According to a further preferred embodiment, at least one packaging wall may comprise an impregnated portion. Preferably, the impregnated portion may be integrally formed with at least one packaging wall. Preferably, the food packaging may be provided as a single piece.

[0058] Thereby, the transparent part can be provided as a window that is part of the same structure and material that forms the food packaging. Thus, unlike the prior art, it is not necessary to provide the window from a separate material that can provide transparency. Thus, the recycling process of the food packaging can be greatly simplified. Also, the mechanical stability and barrier properties of the food packaging can be improved, since the food packaging can be formed from only one component or only a few connected components.

[0059] According to a preferred embodiment, the food packaging may be a tray, a cup, a (half) bottle.

[0060] Here, for example, a bottle may be considered as a hollow, narrow-necked container for holding a liquid.

[0061] It is therefore possible to provide food packaging in a form suitable for many different food applications.

[0062] According to a further preferred embodiment, the food packaging may comprise a lid. Here, the lid may preferably comprise an impregnated portion. Preferably, the packaging interior may be closed with the lid. For example, the packaging interior may be closed with the lid by applying heat sealing and / or ultrasonic sealing. For example, the lid may be a cap for a bottle or, preferably, a flat cover for a cup, bowl or tray.

[0063] Thereby, the food package can be sealed at the top by a transparent cover at the intended point of sale, which is particularly advantageous for displaying the packaged food products and presenting the food products in supermarkets.

[0064] According to a preferred embodiment, the food packaging may partially or completely, preferably hermetically, enclose a packaging interior for containing an edible product for human and / or animal consumption. For example, the food product (food) may be a liquid, semi-solid or solid product. The food product may be in the form of a powder, granules, paste, gel and / or sauce. Alternatively or additionally, the food product may comprise or be water.

[0065] It is therefore possible to provide protective food packaging for a large number of different food products.

[0066] A further aspect of the invention relates to a food packaging material made of a cellulosic fibrous material having a portion impregnated with a polymer such that the impregnated portion has a (direct) light transmittance of greater than 60% for visible light. Preferably, the food packaging material may be formable to define an interior of a food package, more preferably the impregnated portion may at least partially define said interior.

[0067] Preferably, the food packaging material has a density of 30 g / m 2 ~800g / m 2 More preferably, the food packaging material may have a basis weight of 30 g / m 2 Super, 40g / m 2 Super, 60g / m 2 Super, 80g / m 2 Super, 100g / m 2 Super, 120g / m 2 Super, 140g / m 2 Super, 160g / m 2 Super, 180g / m 2 Super, 200g / m 2 Super, 220g / m 2 Super, 240g / m 2 Super, 260g / m2 Super, 280g / m 2 Super, 300g / m 2 Super, 320g / m 2 Super, 340g / m 2 Super, 360g / m 2 Super, 380g / m 2 Super, 400g / m 2 Super, 420g / m 2 Super, 440g / m 2 Super, 460g / m 2 Super, 480g / m 2 Super, 500g / m 2 Super, 520g / m 2 Super, 540g / m 2 Super, 560g / m 2 Super, 580g / m 2 Super, 600g / m 2 Super, 620g / m 2 Super, 640g / m 2 Super, 660g / m 2 Super, 680g / m 2 Super, 700g / m 2 Super, 720g / m 2 Super, 740g / m 2 Super, 760g / m 2 Super, 780g / m 2 More than 800g / m 2 , and / or 800 g / m 2 Less than 780g / m 2 Less than 760g / m 2 Less than 740g / m 2 Less than 720g / m 2 Less than 700g / m 2 Less than 680g / m 2 Less than 660g / m 2 Less than 640g / m 2 Less than 620g / m 2 Less than 600g / m 2 Less than 580g / m 2 Less than 560g / m 2 Less than 540g / m 2 Less than 520g / m 2 Less than 500g / m 2 Less than 480g / m 2 Less than 460g / m 2 Less than 440g / m 2Less than 420g / m 2 Less than 400g / m 2 Less than 380g / m 2 Less than 360g / m 2 Less than 340g / m 2 Less than 320g / m 2 Less than 300g / m 2 Less than 280g / m 2 Less than 260g / m 2 Less than 240g / m 2 Less than 220g / m 2 Less than 200g / m 2 Less than 180g / m 2 Less than 160g / m 2 Less than 140g / m 2 Less than 120g / m 2 Less than 100g / m 2 Less than 80g / m 2 Less than 60g / m 2 Less than 40g / m 2 Less than or equal to 30 g / m 2 The sheet may have a basis weight of 100 g.

[0068] Preferably, the rigid packaging body may be formed from the packaging material. It is contemplated that the food packaging material may comprise any one of the features discussed above in relation to the food packaging of the first aspect of the invention.

[0069] This provides all the effects and advantages described above for food packaging as well for food packaging materials.

[0070] Further features, advantages, and objectives of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the embodiments of the invention in conjunction with the accompanying drawings, in which, for example, numerals may be omitted from the figures for clarity, but corresponding features may still be present in the figures. [Brief description of the drawings]

[0071] [Figure 1] 1A-1D show schematic cross-sectional views of different steps of an impregnation process of cellulosic fibrous material according to one embodiment of the present invention. [Diagram 2]1A-1D show schematic cross-sectional views of different steps of an impregnation process of cellulosic fibrous material according to one embodiment of the present invention. [Diagram 3] 1A-1D show schematic cross-sectional views of different steps of an impregnation process of cellulosic fibrous material according to one embodiment of the present invention. [Figure 4] 1 shows a schematic front view of an impregnated part according to a different embodiment of the present invention; [Diagram 5] 1A-1D show schematic side views of impregnated parts according to different embodiments of the present invention. [Figure 6] 1 shows a schematic front view of an impregnated part according to a different embodiment of the present invention; [Figure 7] 1 shows a schematic front view of an impregnated part according to a different embodiment of the present invention; [Figure 8] 1 shows schematic cross-sectional views of different embodiments of food packaging according to the present invention; [Figure 9] 1 shows schematic cross-sectional views of different embodiments of food packaging according to the present invention; [Figure 10] 1 shows schematic cross-sectional views of different embodiments of food packaging according to the present invention; [Figure 11] 1 shows schematic cross-sectional views of different embodiments of food packaging according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0072] The figures show different views and embodiments of a three-dimensional food package 100 according to the present invention.

[0073] Figures 8 to 11 show different examples of the food package 100. For example, in Figures 8 and 9 the food package 100 is exemplarily shown as a tray 101, in Figure 10 the food package 100 is exemplarily shown as a cup 102 and in Figure 11 the food package 100 is exemplarily shown as a bottle 103. However, this is not an exhaustive list and other embodiments of the food package 100 are also conceivable, such as for example a box, a capsule or a sachet.

[0074] The three-dimensional food package 100 is made of a cellulosic fibrous material 200, which is exemplarily shown in FIG. 1, where it is exemplarily shown that the cellulosic fibers can form a matrix having interstices 201 between them. For example, the cellulosic fibrous material 200 can include or be paper, paperboard, cellulosic pulp adapted for molding, cellulose nanofiber sheets or films, air-laid cellulose and / or delignified wood.

[0075] The three-dimensional food package 100 defines a package interior V. This is exemplarily shown in Figs. 8 to 11. The package interior may be suitable or configured to contain a food product. The package interior V may be open or closed. For example, the food package 100 may at least partially enclose the package interior V, as exemplarily shown in Fig. 10 or Fig. 11. Alternatively, the food package 100 may completely, preferably hermetically, enclose the package interior V, as exemplarily shown in Figs. 8 and 9, where the package interior V is shown closed by a lid 112. For example, the package interior V may be closed with the lid 112 by applying a heat seal or an ultrasonic seal.

[0076] The package interior V may thereby be bounded by a package wall 110 forming at least a portion of the food package 100. For example, in Figures 10 and 11, the package wall 110 is illustratively shown defining a single body of the food package 100. In comparison, the food package 100 illustratively shown in Figures 8 and 9 comprises at least two package walls 110, one of which may form the lid 112 and the other of which may form the body of the tray 101.

[0077] Here, the packaging wall 110 may generally surround or enclose the packaging interior V such that an opening (of the body) to the space (e.g., the packaging interior V in Figures 8 to 11) may preferably have an opening to one side.

[0078] The body of the food package 100 may be rigid or flexible. The configuration of the body may vary depending on, for example, the application of the food package and / or the intended contents of the food package 100. For example, the body of the food package 100 may be provided to be rigid for a food package 100 that is a food tray 101 or a capsule. In comparison, the body of the food package 100 may be provided to be flexible for a food package 100 that is a pouch or wrap.

[0079] Generally, the body of the food package 100 may be provided as a single piece or may be composed of one or more (single-piece) half shells that may be glued together (e.g. sealed). For example, the food package 100 exemplarily shown in FIG. 11 may be a bottle 103 that may be made of cellulosic molded pulp and / or made of two half shells (half bottles) or may be a single piece. The bottle 103 may be closed by a lid such as a screw cap. Similarly, the food tray 101 as exemplarily shown in FIGS. 8 and 9, respectively, may also be made, for example, from molded cellulosic pulp and / or may be a single piece. The cup 102 exemplarily shown in FIG. 10 may be made of carton and / or may be a single piece. The tray 101 and the cup 102 may be closed with a lid 112 that may, for example, preferably be made of carton.

[0080] At least a portion 111 of the food package 100, which defines at least a portion of the package interior V, is impregnated with a polymer 300. This is exemplarily shown in Figures 4 to 11.

[0081] For example, a solid impregnation process, a liquid impregnation process or a vacuum impregnation process can be used for this purpose. The different steps of the impregnation process are exemplarily shown in Figs. 1 to 3. Here, it is exemplarily shown how the gaps 201 (shown in Fig. 1) between the fibres of the cellulosic fibrous material 200 can be filled with particles of polymer 300. This is exemplarily shown in Fig. 2. The polymer 300 and the cellulosic fibrous material 200 can then be bonded together (e.g. by heat treatment or other treatment methods) to form a preferably continuous impregnated material 230. This is exemplarily shown in Fig. 3.

[0082] Here, the polymer 300 may preferably be a food grade material. Alternatively or additionally, the polymer 300 may be biodegradable. Preferably, the polymer 300 may be provided as a powder and / or may be soluble in a solvent. Advantageously, the polymer 300 may have a similar or identical refractive index to the cellulosic fibrous material 200. For example, the polymer 300 and the cellulosic fibrous material 200 may both have a refractive index of 1.5. Thus, the resulting refractive index of the impregnated material 230 may be uniform.

[0083] Suitable material choices for polymer 300 may be, for example, polyolefins, polyacrylates, polycaprolactones (PCL), polyesters, polyalcohols, polyhydroxyalkanoates (PHAs), thermoplastic starches (TPS), cellulosics, epoxy resins, or any combination thereof.

[0084] As the polyolefin of the polymer 300, polyethylene (PE) or polypropylene (PP) may be used.

[0085] It is also contemplated (in addition or alternatively) to use polyethylene terephthalate (PET), polybutylene adipate terephthalate (PBAT), polylactic acid (PLA), and / or polybutylene succinate-co-butylene adipate (PBSA) as the polyester of polymer 300.

[0086] Further, cellulose acetate (CA), cellulose acetate-butyrate (CAB), cellulose acetate-propionate (CAP), carboxymethyl cellulose acetate butyrate (CMCAB), and / or hydroxymethylethyl cellulose (HMEC) may be used (in addition or alternatively) as the cellulose derivative of polymer 300.

[0087] Additionally, polyvinyl alcohol (PVOH), butenediol vinyl alcohol copolymer (BVOH), polyvinyl acetate (PVAC, PVA) may be used (in addition or alternatively) as the polyalcohol of polymer 300.

[0088] Polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and / or PHBH (random copolymer of (R)-3-hydroxybutyrate (3HB) and (R)-3-hydroxyhexanoate (3HHx)) may be used (in addition or alternatively) as the polyhydroxyalkanoate (PHA) of polymer 300.

[0089] At least one packaging wall 110 may comprise an impregnated portion 111. Here, the impregnated portion 111 may be integrally formed with the at least one packaging wall 110. This is exemplarily shown in all figures.

[0090] The impregnated portion 111 may be provided anywhere in the food package 100. For example, the impregnated portion 111 may be included in a lid 112 of the food package 100, as exemplarily shown in Figure 8. Alternatively or additionally, the body of the food package 100 may include the impregnated portion 111, as exemplarily shown in Figures 9-11. Of course, it is contemplated that the food package 100 may include two or more impregnated portions 111, as exemplarily shown in Figures 8 and 10.

[0091] The portion 111 of the food package 100 is impregnated with the polymer 300 such that the impregnated portion 111 has a (direct) light transmittance of greater than 60% for visible light, thereby providing the cellulosic fibrous material 200 with an integral transparent region.

[0092] In general, the transparency of impregnated portion 111 may increase with increasing impregnation of cellulosic fibrous material 200. Alternatively or additionally, the transparency of impregnated portion 111 may increase with increasing uniformity of distribution of polymer 300 in cellulosic fibrous material 200. Similarly, the transparency of impregnated portion 111 may increase with increasing closeness of the refractive index of polymer 300 to the refractive index of cellulosic fibrous material 200.

[0093] Thus, the impregnated portion 111 may have a light transmittance to visible light of greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, greater than 95%, or 100%.

[0094] Here, transparency may be measured according to industry standards such as ASTM D 1746-03, where light transmittance may be calculated as a percentage ratio of the light intensity when a test piece such as impregnated portion 111 is placed in a test light beam compared to the light intensity when no test piece is in the test light beam.

[0095] As exemplarily shown in FIGS. 4-11, the impregnated portion 111 may form one or more windows in the package interior V for viewing a food product disposed within the food package 100.

[0096] Preferably, the food product may be placed relatively close to the impregnated portion 111. For example, the distance between the impregnated portion 111 and the food product may be less than 1 mm, less than 2 mm, less than 3 mm, less than 4 mm, less than 5 mm, less than 10 mm, less than 15 mm, less than 20 mm, less than 30 mm, less than 40 mm, or less than 50 mm.

[0097] Preferably, the concentration of the polymer 300 contained in the impregnated portion 111 may be continuous, as exemplarily shown in FIG.

[0098] Alternatively or additionally, it is also conceivable that the impregnated portion may be at least partially continuous, as exemplarily shown in Figures 6 and 7. In Figure 6, for example, the impregnated portion 111 may alternate between sections of the packaging wall 110 that contain a high concentration of the polymer 300 and sections 235 that may contain a lower concentration of the polymer 300 or may not contain any polymer 300 at all. In Figure 7, for example, the concentration of the polymer 300 contained in each of the individual sections 231, 232, 233 may be constant, while the concentration of the polymer 300 in the different sections 231, 232, 233 in the longitudinal or transverse direction of the packaging wall 110 may vary. Here, different patterns are used in Figure 7 to indicate the different concentrations.

[0099] In addition, it is also conceivable that the concentration of the polymer 300 in the impregnated portion 111 may vary along its extension direction (e.g. from the packaging interior V to the outside of the food packaging 100) that defines the thickness of the impregnated portion 111. This is exemplarily shown in the schematic cross-sectional side view of Fig. 5. Here, the concentration of the polymer 300 in each of the individual sections 231, 232, 233 may be constant, while the concentration of the polymer 300 in the different (radially) sections 231, 232, 233, 234 of the packaging wall 110 in the impregnated portion 111 may vary. Here, different patterns are used in Fig. 5 to indicate the different concentrations.

[0100] It is further contemplated that, for example, the cellulosic fibrous material 200 may be impregnated with a gradient of impregnation between one side of the material 200 (e.g., through its thickness or across its length). In this case, one side of the impregnating material 230 may contain a higher concentration of polymer 300 than the other side. This is exemplarily shown in Figures 5 and 7. By providing the polymer 300 as a sealable polymer, the side of the impregnating material 230 that contains a higher concentration of polymer 300 than the opposing side may be heat sealable. The impregnating material 300 may then be used to form a three-dimensional package, such as a food package 100, from a flat sheet.

[0101] Alternatively or additionally, the impregnated portion 111 may comprise at least one sealing portion comprising a concentration of polymer 300 capable of sealing the impregnated portion 111 by heat and / or ultrasonic sealing. A sealable polymer may be used which may be different from polymer 300 or may be the same as polymer 300. Preferably, the sealing portion may be provided on one side of the impregnated portion 111, one side comprising a higher concentration of polymer 300 than the corresponding opposite side.

[0102] As previously mentioned, the food package 100 may include multiple impregnated portions 111. As exemplarily shown in Figure 6, at least some of the impregnated portions 111 may be separated from one another by one or more sections 235 of the food package 100, which sections 235 include a lower concentration of polymer 300 or none at all compared to the impregnated portions 111.

[0103] Alternatively or additionally, the impregnated portion 111 may extend throughout the entire food package 100, as exemplarily shown in FIG.

[0104] Preferably, the food package 100 and / or at least the impregnated portion 111 may include an oxygen barrier. For example, the oxygen transmission rate of the food package 100 (as a whole) is 5 cm 3 / m 2 per day (measured at 23° C. and 50% relative humidity).

[0105] Alternatively or additionally, the food packaging 100 and / or at least the impregnated portion 111 may comprise a grease barrier. For example, a standard grease repellency test may result in a kit test value of more than 10 (maximum achievable is 12).

[0106] Alternatively or additionally, the food package 100 and / or at least the impregnated portion 111 may comprise a moisture barrier. For example, the moisture transmission rate of the food package 100 is 5 g / m 2 / day (measured at 23°C / 85% relative humidity).

[0107] In general, the food package 100 may be configured such that it may contain more than 70%, more than 75%, more than 80%, more than 85%, more than 90%, more than 95% by weight cellulose (notwithstanding the provision of the barrier and / or impregnated portion 111). In particular, the food package 100 may be configured in its configuration such that it may be recyclable (in whole or in whole of its components), preferably in a paper recycling process, and / or may be biodegradable (in whole or in whole of its components).

[0108] The food package 100 and / or at least the impregnated portion 111 may have a thickness (e.g., the thickness of the package wall 110) that may be 5 μm or more, 40 μm or more, 0.1 mm or more, 0.5 mm or more, 1 mm or more, 2 mm or more, 3 mm or more, 4 mm or more, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, 0.5 mm or less, 0.1 mm or less, or 40 μm or less, or any combination thereof.

[0109] Further, the food package 100, or at least one package wall 110, if present, has a fiberglass ... 2 ~800g / m 2 More preferably, the food package 100 may have a basis weight of 30 g / m 2 Super, 40g / m 2 Super, 60g / m 2 Super, 80g / m 2 Super, 100g / m 2 Super, 120g / m 2 Super, 140g / m2 Super, 160g / m 2 Super, 180g / m 2 Super, 200g / m 2 Super, 220g / m 2 Super, 240g / m 2 Super, 260g / m 2 Super, 280g / m 2 Super, 300g / m 2 Super, 320g / m 2 Super, 340g / m 2 Super, 360g / m 2 Super, 380g / m 2 Super, 400g / m 2 Super, 420g / m 2 Super, 440g / m 2 Super, 460g / m 2 Super, 480g / m 2 Super, 500g / m 2 Super, 520g / m 2 Super, 540g / m 2 Super, 560g / m 2 Super, 580g / m 2 Super, 600g / m 2 Super, 620g / m 2 Super, 640g / m 2 Super, 660g / m 2 Super, 680g / m 2 Super, 700g / m 2 Super, 720g / m 2 Super, 740g / m 2 Super, 760g / m 2 Super, 780g / m 2 More than 800g / m 2 , and / or 800 g / m 2 Less than 780g / m 2 Less than 760g / m 2 Less than 740g / m 2 Less than 720g / m 2 Less than 700g / m 2 Less than 680g / m 2 Less than 660g / m 2 Less than 640g / m 2 Less than 620g / m 2 Less than 600g / m 2 Less than 580g / m 2 Less than 560g / m 2Less than 540g / m 2 Less than 520g / m 2 Less than 500g / m 2 Less than 480g / m 2 Less than 460g / m 2 Less than 440g / m 2 Less than 420g / m 2 Less than 400g / m 2 Less than 380g / m 2 Less than 360g / m 2 Less than 340g / m 2 Less than 320g / m 2 Less than 300g / m 2 Less than 280g / m 2 Less than 260g / m 2 Less than 240g / m 2 Less than 220g / m 2 Less than 200g / m 2 Less than 180g / m 2 Less than 160g / m 2 Less than 140g / m 2 Less than 120g / m 2 Less than 100g / m 2 Less than 80g / m 2 Less than 60g / m 2 Less than 40g / m 2 Less than or equal to 30 g / m 2 The sheet may have a basis weight of 100 g.

[0110] For example, the food package 100 may be manufactured by a process that may include the following steps.

[0111] A forming process in which the body of the food package 100 may be formed such that the package interior V may be defined. For example, this may be done using a formable cellulosic sheet material in a pulp forming process or in a thermoforming process. Alternatively or additionally, the food package material may be folded and sealed together to form the body having the package interior V.

[0112] In the impregnation step, at least a portion of the material of the (body of) the food package 100 may be impregnated, for example in a solid impregnation process, to form the above-mentioned impregnated portion 111 (including the impregnating material 230). Preferably, the impregnation step may be completed before or after the formation step.

[0113] In a filling process, the interior packaging V may be filled with a food product.

[0114] Finally, the packaging interior V may be sealed closed, for example by sealing the lid 112 onto the body, preferably via a sealing portion.

[0115] The present invention is not limited to the above-described embodiments, insofar as it is encompassed by the scope of the appended claims. All features of the above-described embodiments can be combined in any possible manner and provided interchangeably.

Claims

1. A three-dimensional food package (100) made of a cellulosic fibrous material (200) and defining an interior package (V), wherein at least a portion (111) of the food package (100) that bounds at least a portion of the interior package (V) is impregnated with a polymer (300) such that the impregnated portion (111) has a light transmittance of greater than 60% for visible light. Three-dimensional food packaging (100).

2. The three-dimensional food packaging (100) of claim 1, wherein the impregnated portion (111) has a light transmittance to visible light of greater than 65%, greater than 70%, greater than 75%, greater than 80%, greater than 85%, greater than 90%, greater than 95%, or 100%.

3. The three-dimensional food package (100) of claim 1 or 2, wherein the polymer (300) is a food grade material, is biodegradable, and / or has a similar or identical refractive index to the cellulosic fibrous material (200).

4. The three-dimensional food package (100) of any one of claims 1 to 3, wherein the polymer (300) comprises a polyolefin, a polyacrylate, a polycaprolactone, a polyester, a polyalcohol, a polyhydroxyalkanoate, a thermoplastic starch, a cellulose derivative, an epoxy resin, or any combination thereof.

5. The three-dimensional food package (100) according to any one of claims 1 to 4, wherein the concentration of the polymer (300) contained in the impregnated portion (111) is continuous, at least partially continuous and / or varies along at least one of the directions of extension of the impregnated portion (111) and / or varies between one side of the impregnated portion (111) of the packaging interior (V) and the opposite side of the impregnated portion (111).

6. The three-dimensional food package (100) according to any one of claims 1 to 5, wherein the impregnated portion (111) comprises at least one sealing portion, the sealing portion comprising a concentration of the polymer (300) capable of sealing the impregnated portion (111) by heat sealing and / or ultrasonic sealing, preferably the sealing portion being provided on one side of the impregnated portion (111), the one side of the impregnated portion (111) comprising a higher concentration of the polymer (300) than the corresponding other opposite side.

7. the food packaging (100) comprises a plurality of said impregnated portions (111), preferably at least some of said impregnated portions (111) being separated from one another by one or more sections (235) of said food packaging (100), said one or more sections (235) comprising a lower concentration of said polymer (300) compared to said impregnated portions (111) or comprising no polymer (300) at all; and / or the impregnated portion (111) extends throughout the entire food package (100); The three-dimensional food package (100) according to any one of the preceding claims.

8. The food packaging (100) and / or at least the impregnated portion (111) is preferably 5 cm ３ / m ２ / day, and / or ２ The three-dimensional food package (100) of any one of claims 1 to 7, comprising a moisture barrier having a moisture transmission rate of less than 100 / day.

9. 9. The three-dimensional food package (100) of any one of claims 1 to 8, wherein the food package (100) and / or at least the impregnated portion (111) has a thickness of 5 μm or more, 40 μm or more, 0.1 mm or more, 0.5 mm or more, 1 mm or more, 2 mm or more, 3 mm or more, 4 mm or more, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, 0.5 mm or less, 0.1 mm or less, or 40 μm or less, or any combination thereof.

10. The three-dimensional food package (100) of any one of claims 1 to 9, wherein the cellulosic fibrous material (200) comprises paper, paperboard, molding-compatible cellulosic pulp, cellulose nanofiber sheet or film, air-laid cellulose, and / or delignified wood.

11. The three-dimensional food packaging (100) according to any one of claims 1 to 10, wherein the food packaging (100) comprises more than 70%, more than 75%, more than 80%, more than 85%, more than 90%, or more than 95% by weight of cellulose and / or is recyclable, preferably in a paper recycling process, and / or biodegradable.

12. The three-dimensional food package (100) according to any one of claims 1 to 11, wherein the impregnated portion (111) forms at least one window in the packaging interior (V) for viewing a food product placed within the food package (100).

13. said food package (100) comprises at least one packaging wall (110) defining a body, preferably a rigid or flexible body, of said food package (100) which bounds said package interior (V); Preferably, said at least one packaging wall (110) comprises said impregnated portion (111) and / or Preferably, said impregnated portion (111) is integrally formed with said at least one packaging wall (110). The three-dimensional food package (100) according to any one of the preceding claims.

14. The food packaging (100), or if present, the at least one packaging wall (110), has a hardness of 30 g / m ２ Up to 800 g / m ２ The three-dimensional food package (100) according to any one of claims 1 to 13, having a basis weight of

15. said food packaging (100) being a tray (101), a cup (102), a bottle (103), and / or said food package (100) comprises a lid (112), preferably comprising said impregnated portion (111), and preferably said package interior (V) is closed with said lid (112), preferably by applying a heat seal and / or an ultrasonic seal; and / or said food package (100) partially or completely encloses, preferably hermetically, said package interior (V) for containing an edible product for human and / or animal consumption; The three-dimensional food package (100) according to any one of the preceding claims.

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