packaging

Abstract

Packaging solutions for transporting temperature sensitive products, such as fish and other foods, are described in which the packaging solution comprises a three layered structure of an outer layer, an inner layer and a middle layer. Also described are methods of making the packaging solution and uses of the packaging solution.

Description

[0001] PACKAGING

[0002] Field of the Invention

[0003] The present invention relates to improved packaging solutions, such as boxes, for transporting temperature sensitive products. The invention also relates to methods for making boxes suitable for transporting temperature sensitive products, and uses of the boxes for transporting temperature sensitive products.

[0004] Background

[0005] Fresh seafood, such as salmon, is highly nutritious and rich in protein and essential nutrients such as Omega-3. Each year the Scottish fishing industry lands over 430,000 tonnes of seafood with a gross value of £560 million, making up 5% of Scotland GDP, and this continues to grow. However, fresh seafood has a short shelf-life and on average, over 4% is spoiled during transportation. The short shelf-life and expensive cold-chain transportation lead to high supermarket prices, making fresh seafood unaffordable to many people.

[0006] The current gold standard for transportation of the 657,000 tonnes of fish landed or farmed annually in the UK is expanded polystyrene boxes (EPS) with fresh ice, with 95% of fish worldwide being shipped in this way.

[0007] The current industry standard EPS box is shown in Figure 1. Figure 1 illustrates a typical arrangement for shipping fresh fish from a production facility to a remote customer. A rigid box 1 with a lid 2 is typically used (shown in cross-section). The box 1 and lid 2 are made from expanded polystyrene, having a wall thickness of about 25mm. Fresh fish 3 are placed into the box, and an amount of crushed ice 4 added on top of the fish. The lid 2 is then placed on the box 1, and secured there with an encircling band (not illustrated).

[0008] When these EPS boxes were introduced, it was reported that they would reduce food waste, increase safety and save £900 million by keeping the fish cold and protecting against physical damage. However, according to the Waste and Resources Action Program (WRAP), about 8000 tonnes (estimated value £26 million) of all salmon produced in the UK is still wasted during transit.

[0009] EPS is often labelled as biodegradable. Although theoretically, this may be true, in real terms, it take hundreds of years for EPS to be naturally degraded. This results in high volumes of pollution from this supply chain as EPS has environmental presence throughout its life cycle. Furthermore, studies have demonstrated that styrene can leak from the packaging into the produce contained. Carcinogens have severe health detriments to the consumer which have been linked to cancerous diseases.

[0010] There is therefore a need to reduce the use of EPS boxes by providing an alternative packaging solution. Ideally, the alternative packaging solution will meet the need of the end- to-end supply chain, and / or reduce the amount of pollution caused by the fishing industry and / or be a safer alternative for the consumer.

[0011] Summary

[0012] In a first aspect, there is provided a box for transporting a temperature sensitive product, comprising an inner layer comprising a food contact safe polymer; an outer layer comprising a polymer; and a middle layer between the inner layer and the outer layer comprising an insulating biofoam composition.

[0013] In some embodiments, the insulating biofoam composition is a starch-based biofoam composition.

[0014] In some embodiments, the insulating biofoam composition is a wheat-based biofoam, miscanthus-based biofoam, barley-based biofoam, hemp-based biofoam and / or polylactic acid biofoam.

[0015] In some embodiments, the outer layer comprises a petrochemical based polymer, a plantbased polymer and / or a recycled polymer.

[0016] In some embodiments, the plant based polymer is derived from a plant material selected from the group consisting of hemp, strawberry plants, corn, starch, seaweed, sugarcane, tree-pulp, bamboo fiber, coffee, algae, wheat straw, rice husks and / or nut husks.

[0017] In some embodiments, the plant based polymer is a plant based polypropylene, polyethylene or polyester, in some preferable embodiments, the plant based polymer is a plant based polypropylene.

[0018] In some embodiments, the recycled polymer comprises recycled polypropylene.

[0019] In some embodiments, the outer layer is a composite material comprising the polymer and a reinforcing agent. In some embodiments, the reinforcing agent is plant fibres.

[0020] In some embodiments, the food contact safe polymer is polyethylene (PE) (high density (HDPE) or low density (LDPE)), polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene succinate (PBS), poly(styrene-butadiene-styrene) (SBS), and / or styrene-acrylonitrile resin (SAN).

[0021] In some embodiments, the inner layer is made of a food contact safe polymer. Alternatively, the inner layer comprises a food contact safe polymer coating.

[0022] In some embodiments, at least a portion of the inner layer comprises an antimicrobial composition.

[0023] In some embodiments, the inner layer comprises an antimicrobial composition coating, or comprises an incorporated antimicrobial composition.

[0024] In some embodiments, the inner layer and the outer layer are comprised, at least in part of the same polymer, preferably polypropylene.

[0025] In some embodiments, the inner layer comprises an outwardly facing lip at an opening of the box such that a portion of the inner layer is adjacent to a portion of the outer layer.

[0026] In some embodiments the outer layer is bonded to the inner layer to seal the middle layer between the inner layer and the outer layer. In some such embodiments, the outer layer is glued to the inner layer, or the outer layer is chemically polymerised to the inner layer.

[0027] In some embodiments, the inner layer has a thickness of about 0.5mm to about 2.5mm.

[0028] In some embodiments, the outer layer has a thickness of about 0.5mm to about 2.5mm.

[0029] In some embodiments, the middle layer has a thickness of about 5mm to about 25mm.

[0030] In a second aspect, there is provided a method for making a box suitable for transporting a temperature sensitive product, comprising: moulding an outer layer comprising a polymer; moulding an inner layer comprising a food contact safe polymer; inserting the inner layer inside the outer layer; injecting a liquid capable of forming an insulating biofoam between the outer layer and the inner layer; foaming the liquid to form a middle layer comprising an insulating biofoam between the outer layer and the inner layer.

[0031] In a third aspect, there is provided a method for making a box suitable for transporting a temperature sensitive product, comprising: moulding an outer layer comprising a polymer; moulding an inner layer comprising a food contact safe polymer; moulding a middle layer comprising an insulating biofoam; assembling the middle layer in between the outer layer and the inner layer.

[0032] In some embodiments, the methods further comprise bonding the inner layer to the outer layer to seal the middle layer between the inner layer and the outer layer.

[0033] In a fourth aspect, there is provided use of the box according to the first aspect, or made by the method of the second or third aspects, for transporting a temperature sensitive product.

[0034] Brief Description of the Figures

[0035] Figure 1 illustrates in cross-sectional view, packaged fish produced by a prior art method; Figure 2 illustrates a side view of a box according to an embodiment of the invention. Figure 3 illustrates a cross sectional view along D-D of Figure 2 showing the internal structure of the box of Figure 2.

[0036] Figure 4 illustrates an enlargement of section E of Figure 3 showing the detail of the structure of the box layers.

[0037] Figure 5 illustrates a plan view of a box according to an embodiment of the invention.

[0038] Figure 6 illustrates top and bottom perspective views of a box according to an embodiment of the invention.

[0039] Figure 7 illustrates a side view of a lid according to an embodiment of the invention.

[0040] Figure 8 illustrates an end view of a lid according to an embodiment of the invention. Figure 9 illustrates a plan view of a lid according to an embodiment of the invention.

[0041] Figure 10 illustrates a cross sectional view along E-E of Figure 9 showing the internal structure of the lid of Figures 7-9.

[0042] Figure 11 illustrates an enlargement of section F of Figure 10 showing the detail of the structure of the lid layers.

[0043] Figure 12 illustrates top and bottom perspective views of a lid according to an embodiment of the invention.

[0044] Figure 13 illustrates a cross-sectional view of a stack of boxes according to the invention showing an embodiment where the inner layer comprises an outwardly facing lip to facilitate bonding of the inner layer to the outer layer. Figure 14 illustrates an enlargement of section G of Figure 13 showing the detail of the lip arrangement.

[0045] Figure 15 illustrates a perspective view of a box and lid according to one embodiment of the invention in which the box comprises the lip arrangement as in Figures 13 and 14. The lip arrangement comprises a reinforcing rib and the lid comprises complementary groove. Figure 16 is a flow chart showing a process for preparing a moulded middle layer from biomass starting material.

[0046] Figure 17 is a flow chart showing a streamlined process for preparing a moulded middle layer from biomass starting material.

[0047] Figure 18 outlines the hypothesised chemical processes in the process for preparing a moulded middle layer from biomass starting material.

[0048] Figure 19 illustrates the visual difference in shrinkage as the biomass percentage in the process for producing the biofoam is increased from 2.5% to 6% in a barley based biofoam. Figure 20 illustrates biofoams made from wheat, miscanthus, barley, hemp shiv and hump dust biomass starting materials.

[0049] Figure 21 is a graph showing the compressive strength of biofoams produced from hemp fine (dust), wheat, hemp coarse (shiv), barley and miscanthus biomass starting materials.

[0050] Detailed Description

[0051] The present invention provides an alternative box to EPS for transporting a temperature sensitive product such as fish or seafood. The box is designed to be washable and sterilisable meaning that it is re-usable for up to 10 years. In contrast, the polystyrene used in the EPS boxes is not re-useable, leading to huge amounts going to landfill.

[0052] The box of the invention can be designed to exactly replicate the space and dimensions of current EPS packaging. This ensures that existing handling equipment and logistics infrastructure can be used.

[0053] The box of the invention has a defrost ratio that is the same, or better than, that of EPS boxes.

[0054] The claimed box is suitable for transporting a temperature sensitive product and comprises an inner layer comprising a food contact safe polymer; an outer layer comprising a polymer; and a middle layer between the inner layer and the outer layer comprising an insulating biofoam composition. The term ‘a box’ as used in this disclosure refers to a container with a base and sides and an opening. Typically the base is flat. The base may comprise other features such as drainage holes, stacking features and / or pallet engagement features. The box may be any size, shape or dimension that is suitable for its purpose. Typically, the box has four sides and is rectangular or square, preferably rectangular. Preferably, the box is the same size, shape and dimensions as standard EPS boxes, typically 800mm x 400mm x 200mm, or the same size, shape and dimensions as any similar sized box in the market. This has the advantage of allowing existing handling equipment to be used.

[0055] The box may further comprise a lid. Any lid may be used but preferably, the lid has the same structure as the box itself, for example, the lid may comprise an inner layer comprising a food contact safe polymer; an outer layer comprising a polymer; and a middle layer between the inner layer and the outer layer comprising an insulating biofoam composition. A lid is not essential however, as the boxes are preferably stackable and therefore the base of one box can act as the lid of the box on which it is stacked.

[0056] The box comprises an inner layer comprising a food contact safe polymer. Food contact safe polymers are any polymer that is considered safe to be in contact with food. Food contact safe polymers are regulated in the UK and must be authorised before they can be used and placed on the market in Great Britain. Regulated EU laws of the authorisation requirements include Regulation 10 / 2011 (plastic monomers and additives), Regulation 282 / 2008 (recycled plastic processes) and Directive 2007 / 42 / EC (regenerated cellulose film).

[0057] The food contact safe polymer is preferably resistant to fish-oil permeation.

[0058] The food contact safe polymer can be a food contact safe plastic.

[0059] The food contact safe polymer may be biodegradable or non-biodegradable.

[0060] The food contact safe polymer may be a petrochemical based (derived) polymer, a plantbased (derived) polymer or a recycled polymer, or a combination thereof.

[0061] Suitable food contact safe polymers include, but are not limited to, polyethylene (PE) (high density (HDPE) or low density (LDPE)), polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene succinate (PBS), poly(styrene-butadiene- styrene) (SBS), and / or styrene-acrylonitrile resin (SAN). In preferred embodiments, the food contact safe polymer is polypropylene and / or polyethylene (high density or low density). In particularly preferred embodiments, the food contact safe polymer is polypropylene.

[0062] A box having an inner layer comprising a polymer is advantageous because it enables the inside of the box to be washed and sterilised, meaning that it is re-usable for up to 10 years.

[0063] In some embodiments, the food contact safe polymer is the same as the polymer of the outer layer. This enables the inner layer and the outer layer to be bonded together by polymerisation such that the middle layer is sealed between the inner and the outer layers.

[0064] The inner layer is preferably designed such that the food contact safe polymer is in contact at least a portion of the contents of the box. In some embodiments, the inner layer may be made of the food contact safe polymer. In other embodiments, the inner layer may comprise a food contact safe polymer coating.

[0065] Preferably the inner layer has a thickness of about 0.5mm to about 2.5mm. Most preferably, the inner layer has a thickness of about 1 mm. A smaller thickness reduces the weight of the box which is preferable for cost of transporting the boxes. A smaller thickness is also preferred, especially when the food contact safe polymer is a petrochemical based (derived) polymer, as it minimises the content of virgin material (i.e. non-recycled polymer) used in the boxes.

[0066] At least a portion of the inner layer may further comprise an anti-microbial composition. The anti-microbial composition can slow or prevent spoilage of the temperature sensitive product. As such, an advantage of the inner layer comprising an anti-microbial composition is that the shelf-life of the temperature sensitive product can be increased, in some cases by up to 21 days.

[0067] The inner layer is preferably designed such that the anti-microbial composition is in contact with at least a portion of the contents of the box. The anti-microbial composition may be provided as an anti-microbial coating on the inner layer. Such a coating can be provided by spraying or washing the anti-microbial coating onto the inner surface. Alternatively or additionally, the anti-microbial composition may be incorporated into the inner layer. In this case, incorporated into means that the anti-microbial composition is mixed in with the inner layer when it is made. Suitable anti-microbial compositions are known in the art, such as triclosan-containing coatings, coatings containing silver or copper and their salts and, most preferably, biodegradable antimicrobial agents such as chitosan and chitin. Also suitable is a combination of one or more anti-microbial compositions, such as chitosan and silver nitrate.

[0068] The anti-microbial composition kills bacteria without compromising quality, taste or safety of the product. This leads to a competitive and economic benefit.

[0069] The box comprises an outer layer comprising a polymer. Any polymer may be used. For example, the polymer may be a petrochemical based (derived) polymer, a plant-based (derived) polymer or a recycled polymer, or a combination thereof. In some embodiments, the polymer is a plastic.

[0070] The polymer may be biodegradable or non-biodegradable.

[0071] In some embodiments, the polymer in the outer layer is the same as the food contact safe polymer of the inner layer. This enables the inner layer and the outer layer to be bonded together by polymerisation such that the middle layer is sealed between the inner and the outer layers.

[0072] A petrochemical based polymer may also be referred to as a synthetic polymer. The petrochemical based polymer is derived from petroleum hydrocarbons. Where the polymer is a petrochemical based polymer, it may be, for example, polyethylene (PE) (high density (HDPE) or low density (LDPE)), polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene succinate (PBS), poly(styrene-butadiene-styrene) (SBS), and / or styrene-acrylonitrile resin (SAN). Preferably, the petrochemical based polymer is polypropylene.

[0073] In some embodiments, the petrochemical based polymer in the outer layer is the same as the food contact safe polymer of the inner layer. This enables the inner layer and the outer layer to be bonded together by polymerisation such that the middle layer is sealed between the inner and the outer layers.

[0074] The term ‘a plant based polymer’ (also referred to as a ‘plant-derived polymer’) includes any polymer that is made from plant-derived molecules, as opposed to petroleum-derived molecules (hydrocarbons). The use of plant based polymers is advantageous from an environmental point of view because they are made from renewable materials, whilst petroleum based polymers are made from a finite source of crude oil using energy-intensive processes to extract.

[0075] In some embodiments, the plant based polymer is derived from a plant material selected from the group consisting of hemp, strawberry plants, corn, starch, seaweed, sugarcane, tree-pulp, bamboo fiber, coffee, algae, wheat straw, rice husks and / or nut husks. In some embodiments, the plant material(s) is extracted from a waste stream. For example, a waste stream generated as a result of agricultural activity, such a waste stream produced as a byproduct of crop production. This provides an advantage to using plant materials to produce the plant based polymer for the outer layer, as the plant materials can be removed as waste streams for or from farmers.

[0076] Preferably, the plant based polymer is derived from strawberry plants. Bio-fermented strawberry plant waste can be used to produce the plant based polymer for the outer layer. This has an advantage of removing strawberry plant waste as a waste stream for farmers.

[0077] The plant based polymer may be a plant based plastic. Preferably, the plant based polymer is a plant based polypropylene, polyethylene or polyester, most preferably a plant based polypropylene. However, the outer layer could comprise a natural polymer such as rubber.

[0078] In some embodiments, the plant based polymer is the same as the food contact safe polymer of the inner layer. This enables the inner layer and the outer layer to be bonded together by polymerisation such that the middle layer is sealed between the inner and the outer layers.

[0079] In some embodiments, the polymer in the outer layer may comprise a recycled polymer. The term recycled polymer can mean any polymer that has been previously used, including previously used polymer that has been broken back down into its constituent Monomers, and then processed back into polymer (with or without additional material). The recycled polymer may be, for example, polyethylene (PE) (high density (HDPE) or low density (LDPE)), polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene succinate (PBS), poly(styrene-butadiene-styrene) (SBS), and / or styrene-acrylonitrile resin (SAN). Preferably, the recycled polymer is polypropylene.

[0080] Using recycled polymers has advantages, including reducing waste and therefore reducing the amount of polymer going to landfill. In particularly preferred embodiments, the outer layer is a composite material. The term composite means a polymer blended with another material. In some such preferred embodiments, the polymer is a recycled polymer, most preferably recycled polypropylene. As outlined above, advantages of using recycled polymers include waste reduction, thereby reducing the amount of polymer going to landfill. However, for regulatory approval, it may be necessary for the polymer to be a petrochemical based polymer, preferably petrochemical based polypropylene.

[0081] In preferred embodiments, the composite material comprises the polymer blended with a reinforcing agent. In such embodiments, the outer layer may be referred to as a biocomposite. The use of the reinforcing agent may help to reduce the weight of the polymer used in the outer layer and / or to stabilise the material.

[0082] The reinforcing agent may be any suitable polymer reinforcer including fibres (glass, plant, carbon, polymeric), fillers (silica), nanotechnology-based additives (nanotubes, nanoclay).

[0083] Where the reinforcing agent is a fiber, it is preferably a plant fibre. Suitable plant fibres may be derived from a plant material selected from the group consisting of hemp, strawberry plants, corn, starch, seaweed, sugarcane, tree-pulp, bamboo fiber, coffee, algae, wheat straw, rice husks and / or nut husks. An advantage of using such plant materials to produce the reinforcing agent for the outer layer is that the plant materials can be removed as waste streams for farmers. In particular, use of strawberry plants is beneficial because once the soft fruit has been removed, the plant stalks and leaves end up as waste.

[0084] Preferably, the plant based polymer is derived from strawberry plants. Bio-fermented strawberry plant waste can be used to produce the plant based polymer for the outer layer. This has an advantage of removing strawberry plant waste as a waste stream for farmers. Plant fibres from plants such as hemp are also particularly suitable as reinforcing agents because their stalks have a very high fiber content with excellent mechanical properties.

[0085] In some such embodiments, the outer layer comprises about 50% to about 70% polymer, preferably recycled polymer, and about 30% to about 50% reinforcing agent, preferably fibres, more preferably plant fibres. In particularly preferred embodiments, the outer layer comprises about 60% polymer, preferably recycled polymer, and about 40% reinforcing agent, preferably fibres, more preferably plant fibres. Preferably the outer layer has a thickness of about 0.5mm to about 10.0mm, for example, about 1mm to about 7mm, or about 1.5mm to about 5mm. Most preferably, the outer layer has a thickness of about 2mm. A smaller thickness reduces the weight of the box which is preferable for cost of transporting the boxes. However, the outer layer provides durability and so a thicker outer layer may be preferred. In addition, depending on the polymer used in the outer layer, and whether or not a reinforcing agent is used, the outer layer has the potential for a net carbon gain. Therefore, it may be preferable to have a thicker outer layer for a greater net carbon gain.

[0086] It is an option to add an ID tag into the outer layer. Such a tag enables tracking of the boxes. There are multiple benefits to tracking the boxes, including potential identification of users that are not handling the boxes responsibly, tracking the contents of the box along their journey, tracking the temperatures that the box is exposed to along the journey, and to establish how the contents of the box are handled on the journey.

[0087] The box comprises a middle layer between the inner layer and the outer layer comprising an insulating biofoam composition. The term biofoam composition means a biological or biologically derived foam. The biofoam is typically low-density, airy and flexible. The biofoam composition is insulating, due to the presence of air within the foam which means it is capable of preventing or reducing loss of heat or cold. The middle layer acts as thermal barrier and can provide most of the box’s insulating properties.

[0088] The insulating biofoam composition may be any insulating biofoam composition known in the art. Preferably, the insulating biofoam composition is a starch-based biofoam composition. The insulating biofoam composition may be made from biomass starting material. The insulating biofoam composition may be a biomass-based biofoam. Preferably, the insulating biofoam composition is a wheat-based, miscanthus-based, barley-based, and / or hempbased biofoam. In some embodiments, the insulating biofoam composition is a wheat-based and / or a hemp-based biofoam The insulating biofoam composition may be a polylactic acid biofoam. Where the insulating biofoam composition may be a wheat-based, miscanthus- based, barley-based and / or hemp-based biofoam, the biofoam is made from wheat, miscanthus, barley and / or hemp biomass. The hemp-based biomass may be, for example, hemp shiv (coarse hemp) and / or hemp dust (fine hemp).

[0089] In some embodiments, the insulating biofoam composition is not a polylactic acid biofoam. The use of a middle layer comprising an insulating biofoam composition confers advantages , including improvement of the defrost ratio of the box. Typically, the thermal conductivity of the layers is about the same or better than that of EPS boxes. Thermal conductivity of an EPS box is typically about 0.0157W / mK. The boxes of the present invention may, for example, have thermal conductivities of between about 0.012 and about 0.018W / mK.

[0090] The middle layer being a biofoam is advantageous from an environmental point of view because it is made from renewable materials, and is biodegradable. It is also a net carbon gain material because it enables carbon capture. Also, the biofoam element may be compatible with the inner and outer layers such that the whole box can be ground down at the end of its life and recycled.

[0091] The middle layer should be as thin as possible whilst still providing a box with the same insulation as current comparable EPS boxes. Preferably the middle layer has a thickness of about 5mm to about 25mm. The thickness can be varied depending on the amount of insulation required, with a thicker middle layer resulting in better insulation. However, the middle layer is preferably not so thick as to decrease the internal volume of the box for containing the temperature sensitive products, thereby necessitating an increase in the external dimensions of the box in order to accommodate a typical product load. In particularly preferred embodiments, a thickness of about 15mm to about 20mm gives a good balance between insulation and box volume.

[0092] The middle layer may be present between the inner and outer layers of the sides of the box only. Alternatively, the middle layer may be present between the inner and outer layers of the base of the box only. However, preferably, the middle layer is present between the inner and outer layers of the sides of the box and the base of the box.

[0093] The middle layer preferably fills the entirety of the void between the inner and the outer layers. This can be achieved by using a pre-moulded thermal box made from the biofoam composition. Such a box is then assembled between a pre-moulded outer layer and a premoulded inner layer. Accordingly, in some embodiments, there is provided a method for making a box suitable for transporting a temperature sensitive product, comprising: moulding an outer layer comprising a polymer; moulding an inner layer comprising a food contact safe polymer; moulding a middle layer comprising an insulating biofoam; assembling the middle layer in between the outer layer and the inner layer. The moulded middle layer may be made by the process shown in Figure 16. This process involves macerating or pulping a biomass starting material before soaking it in an alkaline solution (the biomass may alternatively be macerating or pulped in the alkaline solution). Any suitable biomass starting material may be used, for example, wheat biomass, barley biomass, hemp biomass (hemp shiv (hemp coarse) and / or hemp dust (hemp fine)), miscanthus, and / or paper waste. The biomass starting material may optionally contain an additive. The additive may, for example, be chosen to influence the hydrophobicity of the resulting foam which helps to minimise the amount of water that the box absorbs in use. Suitable additives include any bio-derived polymer especially those with thermoplastic properties. As one example, bio-derived polyester may be used as an additive. The amounts of additive in the biomass starting material can be from 0-25 wt%, preferably about 10-20 wt%.

[0094] The alkaline solution is preferably a solution of sodium hydroxide (NaOH) in water. The solution can be weak and is preferably about a 1% solution of NaOH in water. The soaking can be for as long as 24 hours but is preferably 10-20 minutes. The macerating / pulping step breaks down the cellulose in the biomass and increases the surface area which enables the NaOH to more completely penetrate the cellulose. The NaOH reacts with the cellulose and causes the cellulose to swell up with water between the cellulose molecules. This step also results in bacterial nanocellulose and biomass shredding. The resulting slurry is then cast into a mould / container and frozen until solid. Typically, the mass is frozen at -24 °C. The hypothesised chemical process to this point is outlined in Figure 17.

[0095] The frozen cellulose mass is thawed out and acidified and / or washed to a neutral pH (pH 7). The acidification may involve washing with dilute acid, for example dilute hydrochloric acid. The washing may be done with water. It is not essential to acidify / wash to neutral but it does help to maintain lignin in the cellulose which enhances the waterproof properties of the foam. The cellulose now has a foamed structure resulting from the swelling. The foam can be dried and is then ready to use.

[0096] A streamlined version of this process, which may be used, is shown in Figure 18.

[0097] The amount of biomass present in the alkaline solution may be a least about 1%, or at least about 2%, or at least about 3%, or at least about 4%, or at least about 5%, or at least about 6%. The amount of biomass present in the alkaline solution may be up to about 10%, or up to about 9%, or up to about 8%, or up to about 7%. The amount of biomass is typically about 1-10%. Preferably, the amount of biomass is about 2-8%. Most preferably, the amount of biomass is about 5-6%.

[0098] The larger the amount of biomass in the alkaline solution, the less the shrinkage of the resulting foam is upon drying. Figure 19 illustrates the difference in shrinkage as the biomass percentage is increased from 2.5% to 6% in a barley based foam. An increased amount of biomass in the alkaline solution also results in a harder foam.

[0099] The middle layer may alternatively be made by injecting a liquid capable of forming an insulating biofoam into the void between an outer layer and an inner layer and then foaming the liquid to form an insulating biofoam (this may also be referred to as a foamed biopolymer). The foaming may be done (for example) by addition of a foaming agent, and / or by injection of gas, into the liquid to produce a foam structure. An advantage of this method is that the biofoam typically expands to fill the entirety of the void.

[0100] Accordingly, in some embodiments, there is provided a method for making a box suitable for transporting a temperature sensitive product, comprising moulding an outer layer comprising a polymer; moulding an inner layer comprising a food contact safe polymer; inserting the inner layer inside the outer layer; injecting a liquid capable of forming an insulating biofoam between the outer layer and the inner layer; and foaming the liquid to form a middle layer comprising an insulating biofoam between the outer layer and the inner layer. The liquid may be self-foaming, or can be foamed by thermosetting.

[0101] As an alternative, a twin-shot (or two-shot) injection can be used. Twin-shot injection moulding involves combining two different polymers during one machining cycle. In this case therefore, the inner or outer layer is injection moulded in the same machining cycle as the middle layer. The remaining layer (inner or outer) is then injection moulded. Therefore, there is provided a method for making a box suitable for transporting a temperature sensitive product, the box comprising an inner layer comprising a food contact safe polymer; an outer layer comprising a polymer; and a middle layer between the inner layer and the outer layer comprising an insulating biofoam composition, comprising simultaneously moulding the middle layer and either the inner or the outer layer to form a double layer, and then moulding the other of inner or outer layers and assembling with the double layer to provide the box.

[0102] To help adhesion of the middle layer to the outer layer, the inner surface of the outer layer, which is adjacent to the middle layer, may have a rough surface. Similarly, to help adhesion of the middle layer to the inner layer, the exterior surface of the inner layer, which is adjacent to the middle layer, may have a rough surface.

[0103] It is preferable if the middle layer is completely sealed between the inner and the outer layers. This can be achieved by bonding the inner layer to the outer layer such that the middle layer is sealed between the inner layer and the outer layer. The bonding may be by chemical polymerisation, i.e. the outer layer is chemically polymerised to the inner layer. For polymerisation bonding, it is preferable that the food contact safe polymer and the polymer in the outer layer are the same.

[0104] The bonding may also be done by gluing, i.e. the outer layer is glued to the inner layer.

[0105] In some embodiments, the structure of the box may facilitate sealing of the middle layer between the inner layer and the outer layer. For example, the inner layer may comprise an outwardly facing lip at an opening of the box such that a portion of the inner layer is adjacent to, or overlaps with, a portion of the outer layer. In these embodiments, the outwardly facing lip overhangs the middle layer which facilitates the bonding of the inner layer lip to the outer layer.

[0106] In another embodiment, the outer layer may comprise an inwardly facing lip at an opening of the box such that a portion of the outer layer is adjacent, or overlaps with, to a portion of the inner layer. In these embodiments, the inwardly facing lip overhangs the middle layer which facilitates the bonding of the outer layer lip to the inner layer.

[0107] In some embodiments, the box may comprise a lip on both the inner layer and the outer layer.

[0108] The lip may comprise one or more reinforcing ribs, optionally with complementary groove(s) on the lid.

[0109] The box may comprise additional layers between the inner and the outer layers. These additional layers may be any suitable layers, including insulating layers, structural layers, carbon capture layers, and / or antimicrobial layers.

[0110] A box according to this disclosure is shown in Figure 2. Figure 2 includes a section D-D which is shown in Figure 3 and Figure 3 includes a Section E which is shown in Figure 4. Figures 2-4 show a box comprising an outer layer 1 comprising recycled polypropylene comprising plant fibres, an inner layer 3 comprising FDA approved polypropylene, and a middle layer 2 comprising a biofoam layer. Figure 5 shows the box in plan view and Figure 6 provides a top and bottom perspective view of the box. It can be seen from Figure 5 and 6 that this embodiment of the box has drainage holes and handles.

[0111] A lid according to this disclosure is shown in Figures 7-9. Figure 9 includes a section E-E which is shown in Figure 10. Figure 10 further contains a Section F which is shown in Figure 11. It can be seen from Figure 11 that the lid has the same structure as the box of Figure 2-6 in that it comprises an outer layer 1 comprising recycled polypropylene comprising plant fibres, an inner layer 3 comprising FDA approved OEM polypropylene, and a middle layer 2 comprising a biofoam layer. Also shown in Figure 12 is a top and bottom perspective view of the lid.

[0112] The lip arrangement of the box is shown in Figures 13 and 14. Figure 13 shows cross section of the box with the lip arrangement shown in Section G. Section G is shown in more detail in Figure 13. From these Figures, it can be seen that the inner layer 3 comprises an outwardly facing lip 4 at an opening of the box 5 such that a portion of the inner layer lip is adjacent to (or overlaps) a portion of the inner layer. This ensures that the lip overhangs the middle layer 2 and facilitates the bonding of the inner layer to the outer layer to seal the middle layer in-between.

[0113] Figures 13 and14 also shows an embodiment where the lip comprises a reinforcing rib 6 with a complementary groove 7 on the lid 8. This can be seen in perspective view with the lid and box separate in Figure 15.

[0114] Example 1

[0115] To test the thermal properties of the box structures where the middle layer was made of polylactic acid biofoam, a number of ‘plugs’ of material were produced using different polymers and different thicknesses as outlined in the table below. The plugs were tested using the Lees Disc method (for example, using the methodology in ASTM-D7340).

[0116]

[0117] As can be seen from the thermal conductivity data, all five boxes prepared according to the invention had thermal conductivity that was comparable with the standard EPS box. There was an improvement in the thermal conductivity when the thickness of the outer layer was increased from 1mm to 2mm.

[0118] The optimum structure for the boxes of this example was the virgin polypropylene inner layer, polylactic acid biofoam and hemp derived polypropylene (2mm) with a thermal conductivity of 0.0155.

[0119] Example 2

[0120] To explore the effect of different biofoam compositions for the middle layer of the box, a number of different insulating biofoam compositions were prepared from biomass starting material. The insulating biofoam compositions were all starch-based compositions and were prepared from wheat biomass, barley biomass, miscanthus biomass, hemp dust biomass or hemp shiv biomass.

[0121] The foams were prepared by the process outlined in Figures 16 and 17. The biomass was first macerated. The macerated biomass was then soaked at a concentration of 2% biomass (20g / L) in an NaOH aqueous solution (1% solution) for about 20 minutes. During this time, bacterial nanocellulose and biomass shredding occurred and the cellulose in the biomass starting material swelled. The resulting slurry was then cast into a container the desired dimensions to form the middle layer of the box and then frozen until solid. Once frozen solid, the biomass was thawed and rinsed with weak hydrochloric acid to a neutral pH. The biomass was then dried and the resulting biofoam was ready to be used.

[0122] The resulting foams made from each of the different biomass’ can be seen in Figure 20. The thermal conductivity of the resulting foams was tested and the results can be seen in the table below (together with data for EPS, polylactic acid and Kraft pulp (paper waste) for comparison). The foams were tested using the Lees Disc method.

[0123] It can be seen that the EPS foam has a thermal conductivity of 0.0159 W / mK. Four of the biofoams formed by the above method from starch-based biomass (wheat, barley, hemp dust and hemp shiv) had a lower or comparable thermal conductivity to EPS. Therefore, these biofoams are viable alternatives to EPS foam.

[0124] Example 3

[0125] The density of the different foams that were produced in Example 2 were also tested and the results are shown in the table below.

[0126] It can be seen from the above results that, generally, the biofoams produced from biomass (wheat, miscanthus, barley and hemp) were more dense (and therefore heavier) than EPS. However, the increase in density was not significant as the increased weight of the box mass is negligible with respect to the weight of the box together with its contents (up to 20kg of fish).

[0127] Example 4

[0128] The compressive strength of the different foams we investigated. The foams were produced as for Example 2, expect that the biomass loading was 2.5%. The results are shown in the Figure 21. Compression testing was undertaking in line with ASTM D695.

[0129] As can be seen from Figure 21, the biofoams produced from the biomass starting materials (wheat, miscanthus, barley and hemp) compressed more easily than EPS. However, this is not significant because the biofoams form the middle layer of the box which is supported by both the inner and outer layers.

[0130] Example 5

[0131] The variability of thermal conductivity with crop type was explored. Five different foams from different crops of miscanthus were prepared by the method outlined in Example 2. The thermal conductivity of the resulting foams was tested and the results can be seen in the table below (together with data for EPS for comparison). The foams were tested using the Lees Disc method.

[0132] The results show that there is variability with crop type but that, generally, the thermal conductivity remains comparable with, or better than, that of EPS. In particular, it is noted that Misc GNT10 and Misc GNT9 both showed excellent thermal conductivity results. This enables the selection of particular crop types as the starting biomass in order to obtain a desired thermal conductivity. Example 6

[0133] The effect of increasing the biomass loading in the biofoam production process was investigated. As in the above examples, the macerated biomass (barley) was soaked in an NaOH aqueous solution (1% solution) for about 20 minutes. The amount of barley biomass was varied and foams were produced using 2.5% biomass, 3% biomass, 4% biomass, 5% biomass and 6% biomass. Aside from the biomass percentage, the process remained the same as Example 2.

[0134] The results can be seen in Figure 19. It can be seen that increasing the amount of biomass in the process reduces the amount of shrinkage following the casting, freezing and drying steps. It also result in harder foams.

[0135] Advantages

[0136] The economic and environmental advantages of boxes according to the present disclosure are potentially significant. Increased shelf life of temperature sensitive products has the potential to reduce waste, and translate into cheaper food for the end consumer. Being able to increase the shelf life of perishable products reduces pressure on producers, allowing them to maximise their crops / produce, which in turn gives them a higher rate of return.

[0137] Reducing the spoilage of seafood during transportation has the potential to bring down the unit price of the seafood, thus making this highly nutritious food which contains high quality protein and a healthy fat content such as Omega-3 available and affordable for a wider population.

[0138] The use of the box according to the present disclosure, has the potential to reduce the landfill and waste problems caused by EPS boxes. Furthermore, boxes according to the present disclosure which comprise a bio-composite outer layer comprising plant fibres will reduce the amount of plant waste by using a waste product from another industry. Boxes comprising a recycled polymer further reduce landfill and waste by using recycled polymers. Similarly, if the polymer in the outer layer is a plant-based polymer then this will reduce the use of petrochemicals which is beneficial for the environment.

[0139] For the avoidance of any doubt, the terms “a”, “an” and “the” are intended, unless specifically indicated otherwise or the context requires otherwise, to include plural alternatives, e.g., at least one. "Optional" or "optionally" means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0140] Various other modifications to the present invention will be readily apparent to those skilled in the art.

Claims

Claims1. A box for transporting a temperature sensitive product, comprising: an inner layer comprising a food contact safe polymer; an outer layer comprising a polymer; and a middle layer between the inner layer and the outer layer comprising an insulating biofoam composition.

2. The box according to claim 1, wherein the insulating biofoam composition is a starch- based biofoam composition.

3. The box according the claim 1 or claim 2, wherein the insulating biofoam composition is a wheat-based biofoam, miscanthus-based biofoam, barley-based biofoam, hempbased biofoam and / or polylactic acid biofoam.

4. The box according to any one of claims 1 to 3, wherein the outer layer comprises a petrochemical based polymer, a plant-based polymer and / or a recycled polymer.

5. The box according to claim 4, wherein the plant based polymer is derived from a plant material selected from the group consisting of hemp, strawberry plants, corn, starch, seaweed, sugarcane, tree-pulp, bamboo fiber, coffee, algae, wheat straw, rice husks and / or nut husks.

6. The box according to claim 4 or 5, wherein the plant based polymer is a plant based polypropylene, polyethylene or polyester, preferably a plant based polypropylene.

7. The box according to any one of claims 4 to 6, wherein the recycled polymer comprises recycled polypropylene.

8. The box according to any one of claims 1 to 7, wherein the outer layer is a composite material comprising the polymer and a reinforcing agent.

9. The box according to claim 8, wherein the reinforcing agent is plant fibres.

10. The box according to any one of claims 1 to 9, wherein the food contact safe polymer is polyethylene (PE) (high density (HDPE) or low density (LDPE)), polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene succinate(PBS), poly(styrene-butadiene-styrene) (SBS), and / or styrene-acrylonitrile resin (SAN).

11. The box according to any one of claims 1 to 10, wherein the inner layer is made of a food contact safe polymer, or wherein the inner layer comprises a food contact safe polymer coating.

12. The box according to any one of claims 1 to 11 , wherein at least a portion of the inner layer comprises an antimicrobial composition.

13. The box according to claim 12, wherein the inner layer comprises an antimicrobial composition coating, or wherein the inner layer comprises an incorporated antimicrobial composition.

14. The box according to any one of claims 1 to 13, wherein the inner layer and the outer layer are comprised, at least in part, of the same polymer, preferably polypropylene.

15. The box according to any one of claims 1 to 14, wherein the inner layer comprises an outwardly facing lip at an opening of the box such that a portion of the inner layer is adjacent to a portion of the outer layer.

16. The box according to any one of claims 1 to 15, wherein the outer layer is bonded to the inner layer to seal the middle layer between the inner layer and the outer layer.

17. The box according to claim 16, wherein the outer layer is glued to the inner layer, or wherein the outer layer is chemically polymerised to the inner layer.

18. The box according to any one of claims 1 to 17, further comprising a lid.

19. The box according to any one of claims 1 to 18, wherein the inner layer has a thickness of about 0.5mm to about 2.5mm.

20. The box according to any one of claims 1 to 19, wherein the outer layer has a thickness of about 0.5mm to about 2.5mm.

21. The box according to any one of claims 1 to 20, wherein the middle layer has a thickness of about 5mm to about 25mm.

22. A method for making a box suitable for transporting a temperature sensitive product, comprising: moulding an outer layer comprising a polymer; moulding an inner layer comprising a food contact safe polymer; inserting the inner layer inside the outer layer; injecting a liquid capable of forming an insulating biofoam between the outer layer and the inner layer; foaming the liquid to form a middle layer comprising an insulating biofoam between the outer layer and the inner layer.

23. A method for making a box suitable for transporting a temperature sensitive product, comprising: moulding an outer layer comprising a polymer; moulding an inner layer comprising a food contact safe polymer; moulding a middle layer comprising an insulating biofoam; assembling the middle layer in between the outer layer and the inner layer.

24. The method according to claim 22 or 23, further comprising bonding the inner layer to the outer layer to seal the middle layer between the inner layer and the outer layer.

25. Use of the box according to any one of claims 1 to 21 , or made by the method of any one of claims 22 to 24, for transporting a temperature sensitive product.

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