Molded pulp container

Abstract

The present invention relates to a container comprising: a body comprising molded pulp, the body being a truncated cone, the cone being open at the wider end and closed at the narrower end, the closed end having an annular region and a central region, wherein: i) the internal surface of the central region is closer to the wider end than the internal surface of the annular region; and / or ii) the external surface of the central region is further from the wider end than the external surface of the annular region; and a liner affixed to the internal surface of the body, the liner comprising one or more biodegradable polymers.

Description

[0001] MOLDED PULP CONTAINER

[0002] The present invention relates to molded pulp containers formed from molded pulp with affixed liners, as well as methods for producing such 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 molding pulp into containers and adhering plastic liners 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 molded pulp and plastic liner post-use, so that the pulp 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 container comprising: a body comprising molded pulp, the body being a truncated cone, the cone being open at the wider end and closed at the narrower end, the closed end having an annular region and a central region, wherein: i) the internal surface of the central region is closer to the wider end than the internal surface of the annular region; and / or ii) the external surface of the central region is further from the wider end than the external surface of the annular region; and a liner affixed to the internal surface of the body, the liner comprising one or more biodegradable polymers.

[0010] The annular region and the central region may be of about the same thickness. The annular region may have a greater thickness than the central region. The annular region may have a lesser thickness than the central region.

[0011] 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), or 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 20 to 200 g / m2.

[0012] The 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. The at least one inorganic barrier layer may be disposed on the internal surface of the liner.

[0013] The container may further comprise a filter paper contained within the volume defined by the body, optionally wherein at least a portion of the filter paper is affixed to the body and / or, if present, the flange, for example to the internal surface of the liner or, if present, the inorganic barrier layer, or, if present, the sealing layer.

[0014] The wider end of the cone may be provided with a flange extending away from a central axis thereof.

[0015] The container may further comprise a lid affixed to the wider end of the cone or, if present, to the flange. 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 at least one organic sealing layer.

[0016] A second aspect of the present invention relates to a method of forming a container, the method comprising: molding a pulp to form a body, the body being a truncated cone, the cone being open at the wider end and closed at the narrower end, the closed end having an annular region and a central region, wherein: i) the internal surface of the central region is closer to the wider end than the internal surface of the annular region; and / or ii) the external surface of the central region is further from the wider end than the external surface of the annular region; affixing a liner to the internal surface of the body, the liner comprising one or more biodegradable polymers.

[0017] Molding the pulp may comprise pressing the pulp into a mold.

[0018] The annular region and the central region may be of about the same thickness. The annular region may have a greater thickness than the central region. The annular region may have a lesser thickness than the central region.

[0019] The wider end of the cone may be provided with a flange extending away from a central axis thereof.

[0020] Affixing the liner may comprise lamination of the liner to the body.

[0021] 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.

[0022] The method may further comprise affixing a filter paper, the filter paper contained within the volume defined by the body, optionally the filter paper being affixed to the internal surface of the body and / or, if present, to the flange. The method may further comprise affixing a lid to the wider end of the cone or, if present, the flange.

[0023] A third aspect of the present invention relates to a packaged foodstuff or beverage ingredient comprising the molded pulp container of the first aspect of the present invention enclosing a foodstuff or a beverage ingredient.

[0024] A fourth aspect of the present invention relates to the use of the molded pulp container of the first aspect of the present invention for packaging a foodstuff or a beverage ingredient.

[0025] Brief Description of the Drawings

[0026] Fig. 1 shows cross sectional views of containers according to the present invention. Figs. 1a, 1b, 1c, and 1d show embodiments wherein the external surface of the central region is further from the open end of the body than the external surface of the annular region. Figs. 1e, 1f, 1g, and 1h show embodiments wherein the internal surface of the central region is closer to the open end of the body than the internal surface of the annular region. Fig. 1 i shows an embodiment wherein the external surface of the central region is further from the open end of the body than the external surface of the annular region and the internal surface of the central region is closer to the open end of the body than the internal surface of the annular region.

[0027] Detailed Description

[0028] The first aspect of the present invention relates to a container comprising a body comprising molded pulp.

[0029] Molded pulp refers to the material formed by the moulding of fibrous material. The fibrous materials are typically cellulosic and may be obtained by recycling processed fibre sources, such as paper or cardboard, or obtained directly from natural fibre sources, such as sugarcane bagasse, bamboo, and straw. Molded pulp articles, such as containers, are commonly used for packaging and are widely considered to be sustainable. The molded pulp may have a grammage in the range of 400 to 800 g / m2.

[0030] The body is in the shape of a truncated cone, the cone being open at the wider end and closed at the narrower end. The closed end has an annular region and a central region. In some embodiments, the internal surface of the central region is closer to the wider end than the internal surface of the annular region. This internally raised central region provides reinforcement to the base of the container, reducing deformation when it is pierced by a needle. In embodiments where the molded pulp container further comprises a filter paper, the raised section also prevents the filter paper from being pierced by a needle inserted into the base of the container. The internal surface may be raised by contouring the molded pulp that forms the base while maintaining approximately constant thickness (see Fig. 1e). The internal surface may be raised by the central region comprising thicker molded pulp than the annular region (see Fig. 1f). The internal surface may be raised by contouring the molded pulp that forms the base and by the central region comprising thicker molded pulp than the annular region (see Fig. 1g). The internal surface may be raised by contouring the molded pulp that forms the base to a greater extent than the central region is thinner than the annular region (see Fig. 1h).

[0031] In other embodiments, the external surface of the central region is further from the wider end than the external surface of the annular region. This externally raised central region provides reinforcement to the base of the container, reducing deformation when it is pierced by a needle. The external surface may be raised by contouring the molded pulp that forms the base while maintaining approximately constant thickness (see Fig.1a). The external surface may be raised by the central region comprising thicker molded pulp than the annular region (see Fig. 1b). The external surface may be raised by contouring the molded pulp that forms the base and by the central region comprising thicker molded pulp than the annular region (see Fig. 1c). The external surface may be raised by contouring the molded pulp that forms the base to a greater extent than the central region is thinner than the annular region (see Fig. 1d).

[0032] In certain embodiments, the internal surface of the central region is closer to the wider end than the internal surface of the annular region and the external surface of the central region is further from the wider end than the external surface of the annular region. Both the internal and external surfaces may be raised by the central region comprising thicker molded pulp than the annular region (see Fig. 1 i).

[0033] The container further comprises a liner affixed to the internal surface of the body, the liner comprising one or more biodegradable polymers. The liner provides barrier properties to the container, limiting or preventing the movement of moisture and / or gases therethrough. The liner covers substantially the entire internal surface of the molded pulp and is preferably adhered to substantially the entire internal surface of the molded pulp.

[0034] 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 molded pulp, 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 from 60 to 150 g / m2. By using biodegradable polymer liners with the molded pulp, the entire container can be composted directly without the need for post-use processing.

[0035] The liner may be a multilayer. 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).

[0036] The molded pulp 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.

[0037] The molded pulp 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.

[0038] The molded pulp container may further comprise a filter paper contained within the volume defined by the molded pulp container. The filter paper is preferably affixed to the internal surface of the molded pulp container and / or, if present, 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 molded pulp container and / or the flange, the internal volume defined by the molded pulp container is divided into two volumes. In one example, the filter paper is affixed around the circumference of the internal surface of the molded pulp container and / or the flange, 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 molded pulp container.

[0039] The wider end of the truncated cone may be provided with a flange extending away from the central axis thereof. In embodiments comprising a flange, the liner may additionally cover and, optionally, be affixed to, the flange.

[0040] The molded pulp container may further comprise a lid affixed to open end of the molded pulp container or, if present, the flange. The lid is affixed around the entirety of the open end, thereby sealing the molded pulp container. This allows for the extended storage of goods within the molded pulp 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 open end or, if present, the flange. In embodiments, a portion of the lid extends beyond the perimeter of the open end or, if present, the flange. Such a portion provides a tab for the removal of the lid.

[0041] 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.

[0042] 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.

[0043] A second aspect of the present invention relates to a method of forming a container, the method comprising molding a pulp to form a body and affixing a liner to the internal surface of the body, the liner comprising one or more biodegradable polymers. The body is a truncated cone, the cone being open at the wider end and closed at the narrower end, the closed end having an annular region and a central region. In some embodiments, the internal surface of the central region is closer to the wider end than the internal surface of the annular region. In other embodiments, the external surface of the central region is further from the wider end than the external surface of the annular region. In certain embodiments, the internal surface of the central region is closer to the wider end than the internal surface of the annular region and the external surface of the central region is further from the wider end than the external surface of the annular region.

[0044] In some embodiments, the internal surface of the central region is closer to the wider end than the internal surface of the annular region. This internally raised central region provides reinforcement to the base of the container, reducing deformation when it is pierced by a needle. In embodiments where the molded pulp container further comprises a filter paper, the raised section also prevents the filter paper from being pierced by a needle inserted into the base of the container. The internal surface may be raised by contouring the molded pulp that forms the base while maintaining approximately constant thickness (see Fig.le). The internal surface may be raised by the central region comprising thicker molded pulp than the annular region (see Fig. 1f). The internal surface may be raised by contouring the molded pulp that forms the base and by the central region comprising thicker molded pulp than the annular region (see Fig. 1 g). The internal surface may be raised by contouring the molded pulp that forms the base to a greater extent than the central region is thinner than the annular region (see Fig. 1h).

[0045] In other embodiments, the external surface of the central region is further from the wider end than the external surface of the annular region. This externally raised central region provides reinforcement to the base of the container, reducing deformation when it is pierced by a needle. The external surface may be raised by contouring the molded pulp that forms the base while maintaining approximately constant thickness (see Fig.1a). The external surface may be raised by the central region comprising thicker molded pulp than the annular region (see Fig. 1b). The external surface may be raised by contouring the molded pulp that forms the base and by the central region comprising thicker molded pulp than the annular region (see Fig. 1c). The external surface may be raised by contouring the molded pulp that forms the base to a greater extent than the central region is thinner than the annular region (see Fig. 1d).

[0046] In certain embodiments, the internal surface of the central region is closer to the wider end than the internal surface of the annular region and the external surface of the central region is further from the wider end than the external surface of the annular region. Both the internal and external surfaces may be raised by the central region comprising thicker molded pulp than the annular region (see Fig. 1 i).

[0047] Molding the pulp comprises pressing the pulp into a mold using a block. The block has the inverse shape to the mold. The surfaces of the mold and block may be at constant separation when pressing the pulp to produce a molded pulp container with substantially constant thickness. Alternatively, there may be areas where the surfaces of the mold and block are at a greater separation to provide areas of thicker pulp (as described above). Optionally, the pressing may further comprise heating the pulp. For example, the mold and / or block may comprise an internal heater or be subjected to external heaters prior to pressing.

[0048] Affixing the liner to the internal surface of the body may be done using any suitable means. Preferably the liner is adhered to substantially all of the internal surface of the body. In embodiments, affixing the liner comprises the use of adhesives to adhere the liner to the internal surface of the body. Alternatively, affixing the liner comprises laminating the liner to the internal surface of the body (e.g. by thermolamination). In some embodiments, affixing the liner to the body occurs simultaneously with molding the pulp to form the body. In other embodiments, the pulp is molded to form the body prior to affixing the liner.

[0049] 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. Any suitable method may be used, such as chemical vapour deposition techniques (e.g. plasma enhanced CVD).

[0050] 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.

[0051] The method may further comprise affixing a filter paper to the molded pulp container, the filter paper contained within the volume defined by the molded pulp container. Preferably, the filter paper is affixed to the internal surface of the molded pulp container and / or, if present, to the flange, for example, to divide the volume defined by the molded pulp container into two, such as a lower volume and an upper volume.

[0052] The method may further comprise affixing a lid to the open end of the body or, if present, to the flange. The lid may be affixed by any suitable means, such as heat sealing or ultrasonic welding.

[0053] 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 molded pulp container. The foodstuff or beverage ingredient is placed within the molded pulp container prior to affixing the lid.

[0054] The third aspect of the present invention relates to a packaged foodstuff or beverage ingredient comprising the molded pulp container as described herein enclosing a foodstuff or beverage. By being packaging within the molded pulp 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.

[0055] The fourth aspect of the present invention relates to the use of the molded pulp container as described herein for packaging a foodstuff or beverage ingredient.

Claims

CLAIMS:1 . A container comprising: a body comprising molded pulp, the body being a truncated cone, the cone being open at the wider end and closed at the narrower end, the closed end having an annular region and a central region, wherein: i) the internal surface of the central region is closer to the wider end than the internal surface of the annular region; and / or ii) the external surface of the central region is further from the wider end than the external surface of the annular region; and a liner affixed to the internal surface of the body, the liner comprising one or more biodegradable polymers.

2. The container of claim 1 , wherein: i) the annular region and the central region are of about the same thickness; or ii) the annular region has a greater thickness than the central region; or iii) the annular region has a lesser thickness than the central region.

3. The container of claim 1 or claim 2, wherein the one or more biodegradable polymers are selected from the list of: polyhydroxyalkanoates (PHAs), polyhydroxybutyrate (PH B) 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), or combinations thereof.

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

5. The container of any preceding claim, wherein the liner is present in an amount of from 20 to 200 g / m2.

6. The container of any preceding claim, 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.

7. The container of claim 6, wherein the at least one inorganic barrier layer is disposed on the internal surface of the liner.

8. The container of any preceding claim, further comprising a filter paper contained within the volume defined by the body, optionally wherein at least a portion of the filter paper is affixed to the body and / or, if present, to the flange, for example to the internal surface of the liner or, if present, the inorganic barrier layer.

9. The container of any preceding claim, wherein the wider end of the cone is provided with a flange extending away from a central axis thereof.

10. The container of any preceding claim, further comprising a lid affixed to the wider end of the cone or, if present, to the flange.

11. The 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 at least one organic sealing layer.

12. A method of forming a container, the method comprising: molding a pulp to form a body, the body being a truncated cone, the cone being open at the wider end and closed at the narrower end, the closed end having an annular region and a central region, wherein: i) the internal surface of the central region is closer to the wider end than the internal surface of the annular region; and / or ii) the external surface of the central region is further from the wider end than the external surface of the annular region; affixing a liner to the internal surface of the body, the liner comprising one or more biodegradable polymers.

13. The method of claim 12, wherein molding the pulp comprises pressing the pulp into a mold.

14. The method of claim 12 or claim 13, wherein:i) the annular region and the central region are of about the same thickness; or ii) the annular region has a greater thickness than the central region; or iii) the annular region has a lesser thickness than the central region.

15. The method of any of claims 12 to 14, wherein the wider end of the cone is provided with a flange extending away from a central axis thereof.

16. The method of any of claims 12 to 15, wherein affixing the liner comprises lamination of the liner to the body.

17. The method of any of claims 12 to 16, 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.

18. The method of any of claims 12 to 17, further comprising further comprising affixing a filter paper, the filter paper contained within the volume defined by the body, optionally the filter paper being affixed to the internal surface of the body and / or, if present, to the flange.

19. The method of any of claims 12 to 17, further comprising affixing a lid to the wider end of the cone or, if present, the flange.

20. A packaged foodstuff or beverage ingredient comprising the molded pulp container of any of claims 1 to 11 enclosing a foodstuff or a beverage ingredient.

21. The use of the molded pulp container of any of claims 1 to 11 for packaging a foodstuff or a beverage ingredient.

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