Folded paper container with integrated barriers

Abstract

The present application relates to a precursor for a paper container, the precursor comprising paperboard and comprising: a base section, the base section having the shape of a polygon with N sides; and N wall sections, each wall section being joined to one of the N sides at a proximal end thereof. The present application further relates to a paper container formed from the precursor and a method of forming the paper container.

Description

[0001] FOLDED PAPER CONTAINER WITH INTEGRATED BARRIERS

[0002] The present invention relates to paper containers formed from cut and folded paperboard with affixed liners, as well as precursors for said containers and methods of producing said containers.

[0003] Background

[0004] Containers for products and for use as packaging are increasingly made from biodegradable materials, including compostable materials, such as paper or moulded pulp. However, these materials based on cellulose fibre have poor barrier properties and limited resistance to water, leaving their contents vulnerable to environmental factors and leading to a limited shelf life.

[0005] Some applications are more challenging, requiring the materials of the container to react to particular conditions (e.g. on exposure to water) in predictable and reproducible ways. In addition, certain applications require containers to take a specific form and in order to ensure compatibility with existing systems and apparatus.

[0006] It is known to form containers by folding suitably shaped paperboard and mutually adhering to form a container. Where necessary, plastic liners are adhered to the internal surfaces of these containers to provide a barrier material and impart resistance to fluids. In some more recent iterations, these plastic liners are adhered using heat-sensitive or water-soluble adhesives to allow separation of the paperboard and plastic liner post-use, so that the paperboard may be recycled or composted. However, the requirement to provide specific post-use recycling systems adds complexity and, ultimately, cost to the consumer.

[0007] It is the object of the present invention to address at least one of the foregoing problems.

[0008] Summary of the Invention

[0009] A first aspect of the present invention relates to a precursor for a paper container, the precursor comprising paperboard and comprising a base section, the base section having the shape of a polygon with N sides; and N wall sections, each wall section being joined to one of the N sides at a proximal end thereof. N may be a natural number from 3 to 20, such as 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, or 20, preferably N is an even natural number from 4 to 20, such as 4, 6, 8, 10, 12, 14, 16, 18, or 20.

[0010] Each wall section may be a quadrilateral, such as a rectangle or a trapezoid. One or more of the wall sections may further comprise one or more lateral extensions, the one or more lateral extensions disposed on one or both of the sides of the wall section proximate to adjacent wall sections. The one or more lateral extensions may be present on alternate wall sections or on each of the wall sections. One or more of the wall sections further comprise a flange extension at a distal end thereof. The flange extensions may be present on alternate wall sections or on each of the wall sections.

[0011] A second aspect of the present invention relates to a paper container, the paper container comprising: a precursor comprising paperboard and comprising: a base section, the base section having the shape of a polygon with N sides; and

[0012] N wall sections, each wall section being joined to one of the N sides at a proximal end thereof. the precursor being folded such that the sides of adjacent wall sections are in mutual contact; and a liner affixed to the internal surface of the folded precursor, the liner comprising one or more biodegradable polymers.

[0013] The precursor may be as defined in the first aspect of the present invention.

[0014] The one or more biodegradable polymers may be selected from the list of: polyhydroxyalkanoates (PHAs), polyhydroxybutyrate (PHB) and co-polymers thereof, polybutylenesuccinate (PBS), poly(butylene succinate-co-butylene adipate) (PBS- A / PBSa), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), cellulose acetate, starch, polyvinylalcohol (PVOH), ethylene vinyl alcohol (EVOH), butenediol vinyl alcohol co-polymer (BVOH), and combinations thereof. The liner may comprise a layer of BVOH laminated between layers of biodegradable polyester, such as PHAs, PBSA, or PBHAT. The liner may be present in an amount of from 20 to 200 g / m2, preferably in an amount of from 60 to 150 g / m2.

[0015] The paper container may further comprise at least one inorganic barrier layer selected within the list of: metals, metalloids, oxides thereof, or a combination thereof, such as aluminium, AIOx, SiOx, and combinations thereof, optionally wherein the at least one inorganic barrier layer is disposed on the internal surface of the liner.

[0016] The paper container may further comprise a sealing layer, disposed on the internal surface of the liner or, if present, the inorganic barrier layer.

[0017] The paper container may further comprise a filter paper contained within the volume defined by the paper container, optionally wherein at least a portion of the filter paper is affixed to the paper container, for example to the internal surface of the liner or, if present, the inorganic barrier layer.

[0018] The paper container may further comprise a lid affixed to the distal ends of each of the wall sections or, if present, to the flange formed by the flange extensions. The lid may comprise a laminate material comprising, from its outer side to its inner side: a paper layer having a grammage in the range of 50 to 150 g / m2, at least one organic barrier layer comprising a biodegradable polymer, optionally, an inorganic barrier layer, and optionally, at least one sealing layer.

[0019] A third aspect of the present invention relates to a method of forming a paper container comprising: folding a precursor according to the first aspect of the present invention such that the sides of adjacent wall sections are in mutual contact; and affixing a liner to the internal surface of the folded precursor, the liner comprising one or more biodegradable polymers.

[0020] Affixing the liner may comprise lamination of the liner to the body. The method may further comprise depositing at least one inorganic barrier layer selected within the list of: metals, metalloids, oxides thereof, or a combination thereof, such as aluminium, AIOx, SiOx, and combinations thereof.

[0021] The method may further comprise depositing a sealing layer.

[0022] The method may further comprise affixing a filter paper, the filter paper contained within the volume defined by the paper container, optionally the filter paper being affixed to the internal surface of the paper container.

[0023] The method may further comprise affixing a lid to the distal ends of each of the wall sections or, if present, to the flange formed by from the flange extensions.

[0024] A fourth aspect of the present invention relates to a packaged foodstuff or beverage ingredient comprising the paper container of the second aspect of the present invention enclosing a foodstuff or a beverage ingredient.

[0025] A fifth aspect of the present invention relates to the use of the paper container of the second aspect of the present invention for packaging a foodstuff or a beverage ingredient.

[0026] Brief Description of the Drawings

[0027] Fig. 1 shows a plan view of a precursor having an 8-sided base (in the form of a regular octagon) with trapezoidal wall sections (the wall sections being isosceles trapezoids broadening as they extend from the base.

[0028] Figs. 2A and 2B show the precursor of Fig. 1 following assembly into a paper container in a side view (Fig. 2A) and a plan view (Fig. 2B).

[0029] Fig. 3 shows a plan view of a precursor as in Fig. 1 with lateral extensions extending from both sides of alternate wall sections.

[0030] Fig. 4 shows a plan view of a precursor as in Fig. 1 with flange extensions extending from the distal ends of alternate wall sections. Figs. 5A and 5B show the precursor of Fig. 4 following assembly into a paper container in a side view (Fig. 5A) and a plan view (Fig. 5B).

[0031] Detailed Description

[0032] The first aspect of the present invention relates to a precursor for a paper container. The precursor comprises paper, paperboard, cardboard, or other suitable planar cellulosic material. It will be understood that the material of the precursor is one that is able to be cut and folded to form the container without tearing or otherwise being mechanically compromised (optionally the folding being done along crease lines formed in the material). The paper may have a grammage in the range of 100 to 400 g / m2, preferably in the range of 150 to 300 g / m2.

[0033] The shape of the precursor 10 is that it has a base section 20, the base section 20 having the shape of a polygon with N sides; and N wall sections 30, each wall section 30 being joined to one of the N sides at a proximal end 40 thereof. Accordingly, the precursor 10 has the base section 20 at the centre with the wall sections 30 extending radially therefrom. For the avoidance of doubt, each wall section 20 occupies the totality of the N side of the base section 20 from which it extends.

[0034] N is a natural number (i.e. a positive integer) greater than or equal to 3. This is the minimum number of wall sections 20 required to form a container 50 having an open top. In theory, N has no upper limit, with the shape of the base section 20 becoming an increasingly accurate approximation of a circle as N increases. However, due to practical limits, such as for the tooling, the accuracy and precision of cuts, and the limitations of the material from which the precursor 10 is formed, N should be 20 or fewer. As such, N may be selected from 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, and 20. Preferably, N is from 6 to 14, such as from 8 to 12. These values for N provide a good balance between complexity and approximation of a circular shape.

[0035] In embodiments, N is an even natural number from 4 to 20. N may be selected from 4, 6, 8, 10, 12, 14, 16, 18, and 20. N being an even number allows for precursors 10 and paper containers in which alternate wall sections 30 have particular properties (such as being a different shape) or features (such as lateral extensions 70 or flange extensions 80). Preferably N is selected from even numbers from 6 to 14, such as 8, 10, or 12. These values for N provide a good balance between complexity and approximation of a circular shape.

[0036] The base section 20 may be a regular polygon with N sides (e.g. an equilateral triangle, a square, or a higher regular polygon). Alternatively, the base section 20 may be irregular in that one or more pairs of opposing sides are extended in comparison to the remaining sides (e.g. a rectangle). Further alternatively, the base section 20 may be an irregular polygon.

[0037] When folded to form the paper container 50, the wall sections 30 abut one another to provide a container with a closed wall and an open top. The sides of the adjacent wall sections 30 are preferably the same length. It is preferred that the distance between the distal end 60 and the proximal end 40 of each wall section 20 is the same. This provides a paper container 50 with a constant height.

[0038] One or more of the wall sections 30 may be a quadrilateral. The quadrilateral may be a rectangle or a trapezoid. Alternatively, or additionally, one or more of the wall sections 30 may be a triangle.

[0039] For the avoidance of doubt, a rectangular wall section 30 may be square. In embodiments where all of the wall sections 30 are rectangular, the opening of the container has the same shape and dimensions as the base section 20. In other words, the container will be an N-sided prism with one closed end and one open end.

[0040] Trapezoid includes both those without a line of symmetry and those with a line of symmetry (isosceles trapezoids), with isosceles trapezoids being preferred. Trapezoidal wall sections 30 are joined to the base section 20 by one of their parallel sides. All of the wall sections 30 may be trapezoidal, resulting in a container with an N-sided opening. In some embodiments, all of the wall sections 30 are trapezoidal and narrow as they extend from the base. The resulting container has an opening smaller than the base section 20, but the same shape. In other embodiments, all of the wall sections 30 are trapezoidal and broaden as they extend from the base section 20. The resulting container 50 has an opening larger than the base section 20, but the same shape. Triangle includes right-angled, scalene, isosceles, and equilateral triangles, with isosceles and equilateral being preferred. The inclusion of a triangular wall section 30 results in the opening having one side fewer than the base section 20. In other words, the number of sides for the opening is equal to the number of sides of the base section 20, N, minus the number of triangular wall sections 30. As the number of sides for the opening must be greater than or equal to three, the number of triangular wall sections 30 must be less than or equal to N-3. In other words, the container must comprise at least three quadrilateral wall sections 30 in addition to any triangular wall sections 30. For example, in embodiments where N is an even number, alternate wall sections 30 may be triangular, with the remainder being quadrilateral. The opening of the resulting container has N / 2 sides, for example, a hexagonal base section with wall sections alternating between quadrilateral and square will form a container with a triangular opening.

[0041] One or more of the wall sections 30 may be provided with one or more lateral extensions 70. The lateral extensions 70 may be provided on one or both sides of the wall section 30 that are proximate to adjacent wall sections 30. When folded into the paper container 50, the lateral extensions 70 provide an area of overlap between adjacent wall sections 30 so that additional fixing means may be provided if necessary (such as adhesives). The lateral extensions 70 may be provided on alternate wall sections 30 or on every wall section 30. In some embodiments, the lateral extensions 70 are provided on both sides of alternate wall sections 30. In other embodiments, each wall section 30 has a lateral extension 70 to one side (i.e. in a clockwise or anti-clockwise direction).

[0042] One or more of the wall sections 30 may be provided with a flange extension 80 at the distal end 60 thereof. When folded into a paper container 90, the flange extensions 80 abut to provide a continuous flange 100 around the opening of the container. The provision of this continuous flange 100 reinforces the opening and provides a larger surface area fora lid to adhere to. The flange extensions 80 may be provided on alternate wall sections 30 or on every wall section 30. The distal edge of each flange extension 80 may consist of straight lines substantially parallel to the distal edges 60 of the wall sections 30, such that the outer perimeter of the flange 100 corresponds to the shape of the opening. Alternatively, the distal edge of each flange extension 80 may consist of an arc, such that the circumference of the flange 100 corresponds to a circle.

[0043] The precursor may be formed by application of a suitably shaped die cutter to a blank piece of paper. The precursor may further comprise crease lines to facilitate folding of the precursor when forming the paper container. For example, the precursor may be creased where the wall sections 30 adjoin the base section 20, where the wall sections 30 adjoin the lateral extensions 70 (if present), and / or where the wall sections 30 adjoin the flange extensions 80 (if present).

[0044] The second aspect of the present invention relates to a paper container, the paper container comprising a precursor 10, as described herein, that has been folded so that the wall sections 30 are in mutual contact and a liner affixed to the internal surface of the folded precursor, the liner comprising one or more biodegradable polymers.

[0045] The liner has two functions. Firstly, it provides barrier properties to the container, limiting or preventing the movement of moisture and / or gases through the base and walls of the container. Secondly, it affixes to the folded precursor, thereby causing it to hold its shape and relieve the need to provide adhesives.

[0046] The liner covers substantially the entire internal surface of the folded precursor and is preferably adhered to substantially the entire internal surface of the folded precursor.

[0047] In embodiments comprising lateral extensions 70, these are found within the volume defined by the folded precursor and are considered to form part of the internal surface of the folded precursor, overlapping with the adjacent wall section 30. These may be affixed to adjacent wall sections 30 to provide additional reinforcement and / or temporary fixing of the folded precursor prior to affixing of the liner.

[0048] In embodiments comprising flange extensions 80, the liner may additionally cover and, optionally, be affixed to, the flange 100 that is formed.

[0049] The biodegradable polymer may be any thermoplastic biodegradable polymer. The use of a thermoplastic material allows the liner to be affixed to the internal surface of the folded precursor, and assume the shape thereof, by thermolamination. The one or more biodegradable polymers may be selected from the list of: polyhydroxyalkanoates (PHAs), polyhydroxybutyrate (PHB) and co-polymers thereof, polybutylenesuccinate (PBS), poly(butylene succinate-co-butylene adipate) (PBS-A / PBSa), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), cellulose acetate, starch, polyvinylalcohol (PVOH), ethylene vinyl alcohol (EVOH), butenediol vinyl alcohol co-polymer (BVOH), and combinations thereof. The liner may be present in an amount of from 20 to 200 g / m2, preferably in an amount of from 60 to 150 g / m2. By using biodegradable polymer liners with the paper container, the entire container can be composted directly without the need for post-use processing.

[0050] The liner may be a multilayered structure. In one preferred embodiment, the liner comprises a layer of BVOH laminated between layers of biodegradable polyester, such as PHAs, PBSA, or PBHAT. The thicknesses of the layers of the laminate may be selected to ensure that each of the layers remain contiguous post affixing (e.g. following stretching induced by thermolamination).

[0051] The paper container may comprise at least one inorganic barrier layer selected within the list of: metals, metalloids, oxides thereof, or a combination thereof, such as aluminium, AIOx, SiOx, and combinations thereof. These inorganic barrier layers provide further barrier properties to limit the movement of moisture and / or gases through the paper container. Preferably, the at least one inorganic barrier layer is disposed on the internal surface of the liner. The liner provides a particularly suitable surface for deposition of the one or more inorganic barrier layers. In embodiments wherein the liner is a multi-layered structure, the at least one inorganic barrier layer may be disposed between the layers.

[0052] The paper container may comprise a sealing layer. The sealing layer is disposed on the internal surface of the liner or, if present, the inorganic barrier layer. For the avoidance of doubt, the sealing layer is the innermost of these layers. The sealing layer may be a heat sealing layer. The sealing layer may be a thermoplastic organic polymer. Substantially any food safe thermoplastic polymer may be used, on condition that it has the requisite material properties of robustness and flexibility in the thickness used. In embodiments, the heat sealing layer comprises an ionomer. The sealing layer may be present in an amount of from 2 to 150 g / m2.

[0053] The paper container may further comprise a filter paper contained within the volume defined by the paper container. The filter paper is preferably affixed to the internal surface of the paper container and / or to the flange, for example to the internal surface of the liner or, if present, the inorganic barrier layer, or, if present, the sealing layer. By being affixed to the internal surface of the paper container, the internal volume defined by the paper container is divided into two volumes. In one example, the filter paper is affixed around the circumference of the internal surface of the paper container, dividing the volume into an upper compartment and a lower compartment. Affixing may be achieved by any suitable means, such as ultrasonic welding. The filter paper is useful where the container is to be used for beverage applications. The beverage ingredients are held to one side of the filter paper and water is flowed through the container from this side, removing extracts from the beverage ingredients while leaving the bulk ingredient behind. In one embodiment, the beverage ingredient sits in a top compartment and water flowed through under gravity into the bottom compartment, where it is removed using a perforation through the base of the paper container.

[0054] The paper container may further comprise a lid affixed to the distal ends of the wall sections or, if present, the flange formed from the flange extensions. The lid is affixed around the entirety of the opening, thereby sealing the container. This allows for the extended storage of goods within the container, for example, for a period of up to 9 months. The storage period may be extended by the use of secondary packaging. The perimeter of the lid may correspond to the perimeter of the distal ends of the wall sections or, if present, the flange formed from the flange extensions. In embodiments, a portion of the lid extends beyond the perimeter of the distal ends of the wall sections or, if present, the flange formed from the flange extensions. Such a portion provides a tab for the removal of the lid.

[0055] The lid may comprise a laminate material comprising, from its outer side to its inner side: a paper layer having a grammage in the range of 50 to 150 g / m2, at least one organic barrier layer comprising a biodegradable polymer, optionally, an inorganic barrier layer, and optionally, a sealing layer.

[0056] The organic barrier layer may be any biodegradable polymer as described herein. The inorganic barrier layer may be any inorganic barrier layer as described herein. The sealing layer may be any sealing layer as described herein. In embodiments, the construction of the lid is the same as that of the paper container.

[0057] The third aspect of the present invention relates to a method of forming a paper container, the method comprising folding a precursor 10 as defined herein such that the sides of adjacent wall sections 30 are in mutual contact; and affixing a liner to the internal surface of the folded precursor, the liner comprising one or more biodegradable polymers.

[0058] The method may further comprise cutting a sheet of paper to form the precursor (e.g. using a die cutter).

[0059] Folding the precursor 10 may comprise placing the precursor 10 into a mold. For example, by applying a vacuum to pull the precursor 10 into the mold and / or pressing with a block.

[0060] Once folded to the shape of the final paper container, the liner is placed and affixed to the internal surface of the folded precursor. The liner is preferably affixed to substantially all of the internal surface of the precursor. Affixation may be achieved by any suitable means (such as applying adhesive), but is preferably achieved by lamination (e.g. thermolamination). The liner may be provided in the shape of the internal surface of the folded precursor. Alternatively, the liner may be configured to the shape of the internal surface of the folded precursor during affixation. For example, lamination of a planar liner to the folded precursor within a mold, optionally under vacuum and / or with a block.

[0061] The method may further comprise depositing at least one inorganic barrier layer selected within the list of: metals, metalloids, oxides thereof, or a combination thereof, such as aluminium, AIOx, SiOx, and combinations thereof. Preferably the at least one barrier layer is applied to the internal surface of the liner, between the organic barrier layer and the paper, or, if the liner is a multilayer, between the layers. Any suitable method may be used, such as chemical vapour deposition techniques (e.g. plasma enhanced CVD), transfer metallization, or direct metallization. In certain embodiments, the inorganic barrier layer is provided to the liner prior to affixation of the liner to the folded paper precursor. For example, the inorganic barrier layer may be deposited onto the liner and the two barrier layers are applied to the folded paper precursor as a composite.

[0062] The method may further comprise depositing a sealing layer. The sealing layer may be deposited as an aqueous dispersion and subsequently dried onto the surface of the preceding layer, typically the inorganic barrier layer.

[0063] The method may further comprise affixing a filter paper to the paper container, the filter paper contained within the volume defined by the paper container. Preferably, the filter paper is affixed to the internal surface of the paper container and / or to the flange, for example, to divide the volume defined by the paper container into two, such as a lower volume and an upper volume.

[0064] The method may further comprise affixing a lid to the distal ends of each of the wall sections or, if present, to the flange formed from the flange extensions. The lid may be affixed by any suitable means, such as heat sealing or ultrasonic welding.

[0065] The method may be a method of providing a packaged foodstuff or beverage ingredient, wherein the foodstuff or beverage ingredient is within the volume defined by the paper container. The foodstuff or beverage ingredient is placed within the paper container prior to affixing the lid.

[0066] The fourth aspect of the present invention relates to a packaged foodstuff or beverage ingredient comprising the paper container as described herein enclosing a foodstuff or beverage. By being packaging within the paper container as described herein including a lid, the foodstuff or beverage ingredient has an open shelf life of six months, preferable up to nine months.

[0067] The fifth aspect of the present invention relates to the use of the paper container as described herein for packaging a foodstuff or beverage ingredient. Specific Embodiments

[0068] In certain embodiments, the base section 20 is a regular polygon with 8, 10, or 12 sides and each of the wall sections 30 is an isosceles trapezoid, each of the trapezoids having the same geometry and size and broadening as it extends from the base section 20. The resulting containers 50 have an opening that is broader than the base and approximate a truncated cone.

[0069] These embodiments may include lateral extensions 70, preferably placed on both sides of alternate wall sections 30. These embodiments may include flange extensions 80, preferably placed on alternate wall sections 30. Preferably, one subset of wall sections 30 has the lateral extensions 70 and the second subset of wall sections 30 has the flange extensions 80.

[0070] In certain of these embodiments, the liner comprises a layer of BVOH laminated between layers of biodegradable polyester, such as PHAs, PBSA, or PBHAT. The liner is affixed to the internal surface of the folded precursor by lamination.

[0071] In certain of these embodiments, the paper container has an inorganic barrier layer that is SiOx and / or AIOx. The inorganic barrier layer is applied to the internal face of the liner, preferably by plasma enhanced CVD. A heat sealing layer may be applied to the internal face of the liner or, if present, the inorganic barrier layer.

[0072] In certain of these embodiments, the paper container has a lid affixed to the distal ends of the wall sections 30 or, if present, the flange 100 formed by the flange extensions 80.

Claims

CLAIMS:

1. A precursor for a paper container, the precursor comprising paperboard and comprising: a base section, the base section having the shape of a polygon with N sides; andN wall sections, each wall section being joined to one of the N sides at a proximal end thereof, wherein one or more of the wall sections further comprises one or more lateral extensions, the one or more lateral extensions being disposed on one or both of the sides of the wall section proximate to adjacent wall sections, wherein one or more of the wall sections further comprises a flange extension at a distal end thereof.

2. The precursor of claim 1 , wherein each wall section is a quadrilateral, such as a rectangle or a trapezoid.

3. A paper container, the paper container comprising: a precursor according any of the preceding claims, the precursor being folded such that the sides of adjacent wall sections are in mutual contact and such that the at least one lateral extension is located within a volume defined by the folded precursor, overlapping with the adjacent wall section in order to be part of an internal surface of the folded precursor, and such that the at least one flange extension formed a flange of the paper container; and a liner affixed to the internal surface of the folded precursor and the flange, the liner comprising one or more biodegradable polymers.

4. The paper container of claim 3, wherein the one or more biodegradable polymers are selected from the list of: polyhydroxyalkanoates (PHAs), polyhydroxybutyrate (PHB) and co-polymers thereof, polybutylenesuccinate (PBS), poly(butylene succinate-co- butylene adipate) (PBS-A / PBSa), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), cellulose acetate, starch, polyvinylalcohol (PVOH), ethylene vinyl alcohol (EVOH), butenediol vinyl alcohol co-polymer (BVOH), and combinations thereof.

5. The paper container of claim 4, wherein the liner comprises a layer of BVOH laminated between layers of biodegradable polyester, such as PHAs, PBSA, or PBHAT.

6. The paper container of any of claims 3 to 5, wherein the liner is present in an amount of 20 to 200 g / m2.

7. The paper container of any of claims 3 to 6, further comprising at least one inorganic barrier layer selected within the list of: metals, metalloids, oxides thereof, or a combination thereof, such as aluminium, AIOx, SiOx, and combinations thereof, wherein the at least one inorganic barrier layer is disposed on an internal surface of the liner.

8. The paper container of any of claims 3 to 7, further comprising a sealing layer, disposed on an internal surface of the liner or, if present, the inorganic barrier layer.

9. The paper container of any of claims 3 to 8, further comprising a filter paper contained within the volume defined by the paper container, the filter paper being affixed to the internal surface of the liner or, if present, the inorganic barrier layer, or if present, the sealing layer.

10. The paper container of any of claims 3 to 9, further comprising a lid affixed to the flange of the paper container formed by the flange extensions of the precursor.

11. The paper container of claim 10, wherein the lid comprises a laminate material comprising, from its outer side to its inner side: a paper layer having a grammage in the range of 50 to 150 g / m2, at least one organic barrier layer comprising a biodegradable polymer, optionally, an inorganic barrier layer, and optionally, at least one sealing layer.

12. A method of forming a paper container comprising:16 folding a precursor according to any of claims 1 to 2 such that the sides of adjacent wall sections are in mutual contact, and such that the at least one lateral extension is located within a volume defined by the folded precursor, overlapping with the adjacent wall section in order to be part of an internal surface of the folded precursor, and such that the at least one flange extension formed a flange of the paper container; and affixing a liner by lamination to the internal surface and the flange of the folded precursor, the liner comprising one or more biodegradable polymers.

13. The method of claim 12 further comprising depositing at least one inorganic barrier layer selected within the list of: metals, metalloids, oxides thereof, or a combination thereof, such as aluminium, AIOx, SiOx, and combinations thereof, the at least one inorganic barrier layer being disposed on an internal surface of the liner.

14. The method of any of claims 12 to 13, further comprising depositing a sealing layer on an internal surface of the liner or, if present, on an internal surface of the inorganic barrier layer.

15. The method of any of claims 12 to 14, further comprising affixing a filter paper within a volume defined by the paper container, the filter paper being affixed to an internal surface of the liner or, if present, the inorganic barrier layer, or if present, the sealing layer.

16. The method of any of claims 12 to 15, further comprising affixing a lid to the flange formed by from the flange extensions of the precursor.

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