PACKAGING ITEM

Abstract

The invention relates to a greaseproof and waterproof packaging item comprising a composite material, the material comprising a fibre substrate and a cross-linked naturally derived polysaccharide.

Claims

1. A greaseproof and waterproof packaging item comprising a composite material, the composite material comprising a fibre substrate and a coating, wherein the coating comprises a cross-linked naturally derived polysaccharide.

2. A greaseproof and waterproof packaging item comprising a composite material, the composite material comprising a fibre substrate and a coating, wherein the coating comprises a cross-linked naturally derived polysaccharide and a polyphenol.

3. A packaging item according to claim 1, wherein the coating is applied to the fibre substrate via a reverse roll, meyer bar, curtain coating, gravure coating, air knife, doctor blade, slot die, or a spraying technique.

4. The packaging item according to claim 1, wherein the polyphenol is a tannin.

5. The packaging item according to claim 4, wherein the polyphenol is tannic acid.

6. The packaging item according to claim 1, wherein the cross-linked naturally derived polysaccharide is an alginate.

7. The packaging item according to claim 6, wherein in the alginate is sodium alginate.

8. The packaging item according to claim 1, wherein the cross linked naturally derived polysaccharide forms a coating or barrier to at least a surface of the fibre substrate.

9. The packaging item according to claim 1, wherein the fibre substrate is selected from paper, paperboard, cardboard, vegetable fibres, food waste fibres, and plant based fibres, such as fibres of seaweed origin.

10. The packaging item according to claim 1, wherein the composite material further comprises a bio-based plasticiser.

11. The packaging item according to claim 10, wherein the bio-based plasticiser is selected from the group consisting of konjac glucomannan, Iota-carrageenan, Kappa-carrageenan, low methoxyl pectin, and glycerol.

12. The packaging item according to claim 1, wherein the fibre substrate comprises polyvalent ions, preferably metal cations and most preferably Calcium ions.

13. The packaging item according to claim 1, wherein the composition further comprises one or more plant-derived saccharide components.

14. The packaging item according to claim 13, wherein the saccharide component is derived from algae.

15. The packaging item according to claim 13, wherein the saccharide component is selected from agar, carrageenan and pectin.

16. The packaging item according to claim 1, wherein the item is selected from a cup, box, tray, clamshell, plate, bag, wrap, bottle, brick and cup holder.

17. The packaging item according to claim 1, wherein the coating is applied to an inner surface of the packaging item.

18. The packaging item according to claim 1, wherein the coating is also heat resistant.

Description

BRIEF DESCRIPTION

[0038] The invention is described with reference to the accompanying drawings in which:

[0039] FIG. 1 shows a diagram of a fibre material (1) with a single coating of a crosslinked polysaccharide membrane (2);

[0040] FIG. 2 shows a diagram of a fibre material (1) with a double coating of a crosslinked naturally derived polysaccharide membrane, internal and external (2).

[0041] FIG. 3 shows a plain corrugated sheet of fibre material (1) with an external crosslinked polysaccharide membrane (2)

[0042] FIG. 4 shows a tube made of fibre material (1) with an external crosslinked naturally derived polysaccharide membrane (2)

[0043] FIG. 5 shows a fibre cup (1) with an internal coating of a crosslinked polysaccharide membrane (2);

[0044] FIG. 6 shows a corrugated cardboard box (2) with an external coating of a crosslinked polysaccharide membrane (1). This makes the exterior of the cardboard box waterproof and greaseproof.

[0045] FIG. 7 shows a tetrahedral shape fibre container with an internal coating of a crosslinked naturally derived polysaccharide membrane.

[0046] FIG. 8 shows a parallelepiped shape fiber container with an internal coating of a crosslinked polysaccharide membrane.

[0047] FIG. 9 shows a bottle shape fiber container with an internal coating of a crosslinked naturally derived polysaccharide membrane.

[0048] FIG. 10 shows a fiber urinal bottles container with an internal coating of a crosslinked polysaccharide membrane.

DETAILED DESCRIPTION

[0049] The invention will now be described by way of the following examples. The skilled person will envisage that features which are optional can be used in different combinations to construct various different embodiments and examples of the invention not limited to composites, products, coatings and methods of producing the same.

Example 1—Dispersion Coating onto Flat Paperboard

[0050] A method of forming a greaseproof and waterproof paperboard for conversion into food packaging, according to one embodiment the invention is provided as follows:

[0051] A reel of uncoated paperboard is fed through an apparatus of rollers and passed through a ‘coating head’. Here a viscous polysaccharide solution (10,000 mPa.Math.s) is mechanically applied at a defined thickness to the moving substrate by any of the following methods: air knife, reverse roll, meyer bar, doctor blade, slot die, gravure.

[0052] The coated board is then passed through a series of ovens to dry the aqueous solution onto the surface before being rewound into a new reel.

[0053] The output reel is then passed through a saline solution in the coating section. This is once again dried and rewound into a final reel. This reel is then passed on to board converters for transformation into a 3D food container.

Example 2—Transfer Moulding With Spraying Method

[0054] A method of forming a greaseproof and waterproof tray for short term food storage and delivery, according to one embodiment the invention is provided as follows:

[0055] A 3D tray is formed via fiber thermoforming. Optimally this tray if formed from cellulose fibres and starch as a binder with no additional barrier additives.

[0056] This tray is passed through a multi-headed spray system which applies a layer of saline. This soaks into the fibers before passing through a secondary spray system which applies a layer of polysaccharide solution to the substrate, where it reacts with the saline and forms an insoluble membrane.

[0057] The coated tray is then passed through a conveyer oven for drying and packed into boxes for transport to the end user.

Example 2a: Transfer Moulding and Dipping Method

[0058] A method of forming a waterproof cup, according to an embodiment of the invention is provided as follows:

[0059] A cup was formed through the “Transfer Moulded” moulded pulp process. This is similar to how egg-boxes are made; a cup shaped mesh is mated with a vacuum chamber that draws water through the mesh into the chamber, with the mesh mould suspended above a liquid return pool. The fibrous slurry similar to that of Example 1 is sprayed from below onto the mould, and the vacuum draws the slurry tightly against the mesh, filling all gaps and spaces. When airflow through the mesh has been sufficiently blocked, the excess slurry falls into the return pool for recycling, and the mould advances onward to the drying process, following by separation of the mesh mould from the dried fibre plating.

[0060] The formed cup, still wet, is then dipped in the same polysaccharide solution as in Example 1. The polysaccharide covered cup was then strained and dipped in the Calcium Chloride solution to crosslink the polysaccharide for 10 minutes.

[0061] The cup was rinsed with water to remove any calcium chloride residue and dried to reach the full mechanical strength of dried pulp.

Example 2b: Transfer Moulding With Calcium and Dipping Method

[0062] A method of forming a waterproof container, according to an embodiment of the invention is provided as follows:

[0063] A container was formed through the “Transfer Moulded” moulded pulp process.

[0064] However, in this case, the liquid return pool contained calcium ions in solution within the fibre substrate itself. The pulp mix thus typically comprises a concentration of 0.1-10% calcium.

[0065] The formed moist cup is then dipped in the same polysaccharide solution as in Example 1, causing the ions in the pulp to crosslink immediately. The polysaccharide covered cup was then strained and dipped in a Calcium Chloride solution to further crosslink the polysaccharide for 10 minutes. In one example, glycerol was added to the bath to increase the flexibility.

[0066] The cup was rinsed with water to remove any calcium chloride residue and dried to reach the full mechanical strength of dried pulp.

Example 3—Dry Application and Laminate

[0067] A method of forming a waterproof cup, according to an embodiment of the invention is provided as follows:

[0068] Uncoated card was die cut into the shape of the walls of the cup as well as the bottom. The cup was then formed around a conical rig and was sealed using non water soluble glue: plant-based pine oleoresin.

[0069] The formed cup was then dipped in the same polysaccharide solution as in Example 1. The polysaccharide covered cup was then duly strained, taking care to remove excess as polysaccharide. This is important in such an example as the excess does not adhere as well on dried paper as on wet pulp. For example, a meniscus shaped polysaccharide film would then form should any excess remain, which would not stick tightly to the surface of the cup.

[0070] The strained cup was then dipped in the Calcium Chloride solution (Example 1) to crosslink the polysaccharide for 10 minutes. The cup was rinsed with water to remove any calcium chloride residue and dried to reach the full mechanical strength of dried pulp.

Example 4: Corrugated Packaging

[0071] A method of forming a waterproof corrugated cardboard for boxes, according to an embodiment of the invention is provided as follows:

[0072] The corrugated cardboard is formed from a wavy sheet of paper, called a flute, sandwiched between two flat sheets, called liners. The waterproof polysaccharide layer is applied to any or to all of these components.

[0073] First, a recyclable pulp paper roll of paper is blasted with hot steam layer of polysaccharide. A 1.2% polysaccharide solution is used to achieve a cardboard substrate with 1-6 g/m.sup.2 and optimally 3 g/m.sup.2 of polysaccharide. Glycerol could be optionally added at this stage to further plasticise the substrate.

[0074] The depth of the polysaccharide film should optimally be 40-60 μm, preferably 50 μm. The concentration of polysaccharide (in the part of the cardboard which it permeates) is 7-9% by weight, usually approximately 8% by weight.

[0075] Calcium Chloride solution (Example 1) is sprayed onto the polysaccharide coating. In the case of the sandwiched layer, the solution should be applied before it is fed to the corrugator to create the flute.

[0076] Later the layers are joined together using two single layers and a flute, wherein at least one and preferably all have been laminated with the crosslinked polysaccharide.

[0077] Boxes using the corrugated cardboard composition may be formed by methods well known in the art. A first trimmer may be used to perforate the boards to create flaps and handles. Rubber sponges cushion the blades so that they only cut the necessary areas. During the trimming a press condenses the boxes overlapping panels to level out their depth. A folding machine bends the cardboard along score lines (that the corrugator pre-set) and glue is used to join sections together. Finally, the glued sections are folded, to ensure they are not visible.

[0078] Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in view of the present disclosure.

[0079] All documents mentioned in this specification are incorporated herein by reference in their entirety.

[0080] “and/or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example “A and/or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein.

[0081] Unless context dictates otherwise, the descriptions and definitions of the features set out above are not limited to any particular aspect or embodiment of the invention and apply equally to all aspects and embodiments which are described. Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in view of the present disclosure. While the invention has been described herein in reference to specific aspects, features and illustrative embodiments of the invention, it will be appreciated that the utility of the invention is not thus limited, but rather extends to and encompasses variations, modifications and alternative embodiments, as will be understood by those of ordinary skill in the field.

Additional Aspects of the Disclosure

[0082] 1. A process for making a composite packaging material comprising: [0083] applying a water-based naturally derived polysaccharide solution to a fibre substrate; applying a water-based solution of polyvalent metal to crosslink the naturally derived polysaccharide and form a coating, layer or barrier on the fibre substrate; and drying.

[0084] 2. The process of aspect 1, wherein the water based naturally derived polysaccharide solution comprises a polyphenol.

[0085] 3. The process of any one of aspects 1 to 2, wherein the process further comprising: rinsing the excess of the water-based polyvalent metal from the substrate.

[0086] 4. The process according to any one of aspects 1 to 3, wherein the fibre substrate is at least partially wet or moist, at least on the surface, when applying the water-based naturally derived polysaccharide solution.

[0087] 5. The process according to any of aspects 1 to 4, wherein the water-based naturally derived polysaccharide solution has a higher viscosity than water.

[0088] 6. The process according to aspect 5, wherein the water-based naturally derived polysaccharide solution has a viscosity of more than 500 cps, preferably more than 1000 cps.

[0089] 7. The process of any of aspects 1 to 6, wherein the steps are repeated at least once to produce the composition packing material with a double or multi-layer, coating or barrier.

[0090] 8. The process of any of aspects 1 to 7, wherein the water-based solution of naturally derived polysaccharide comprises a biologically acceptable naturally derived polysaccharide.

[0091] 9. The process according to any of aspects 1 to 8, wherein the water-based solution of polyvalent metal is a metal ion, such as a poly cation.

[0092] 10. The process according to aspect 9, wherein the poly cation is a Calcium ion.

[0093] 11. The process according to any of aspects 1 to 10, wherein the application of the water-based naturally derived polysaccharide may be applied by dipping or spraying.

[0094] 12. The process according to any of aspects 1 to 11, wherein the water-based solution of polyvalent metal may be applied via dipping or spraying.

[0095] 13. The process according to any of aspects 1 to 12, wherein a bio-based plasticiser is added after applying the water based naturally derived polysaccharide solution to the substrate and before applying a water-based solution of polyvalent metal.

[0096] 14. The process according to any of aspects 1 to 13, wherein at least one plant-derived saccharide component is added after applying the water based naturally derived polysaccharide solution to the substrate and before applying a water-based solution of polyvalent metal.

[0097] 15. The process of any of aspects 1 to 14, wherein the fibre substrate is formed by a process comprising: [0098] blending the fibre with water to form a dilute pulp suspension; [0099] draining the suspension through a flat screen to create a mat of randomly interwoven fibres; [0100] pressing to remove water; and sealing by pressure to pre-form the shape of the fibre substrate.

[0101] 16. The process of any of aspects 1 to 15, wherein the a fibre substrate itself comprises a polyvalent ion, preferably a such as a polyvalent metal cation and most preferably calcium ions.

[0102] 17. A method of manufacturing a water and/or oil proof packaging product comprising: forming a composite material by applying a water-based polysaccharide solution, optionally comprising a polyphenol, to a moist or wet fibre-based packaging substrate; applying a water-based solution of polyvalent metal to crosslink the polysaccharide; forming the composite into a desired packaging shape; and drying to form the packaging product.

[0103] 18. A coating for use with a fibre substrate selected from paper, paperboard, cardboard, vegetable fibres, food waste fibres, plant based fibres, the coating comprising one or more layers of crosslinked polysaccharide and optionally comprising a polyphenol.

[0104] 19. A process for making a composite packaging material comprising: [0105] applying a water-based alginate solution to a fibre substrate; applying a water-based solution of polyvalent metal to crosslink the alginate and form a coating, layer or barrier on the fibre substrate; and drying.