GB2543074A

GB2543074A - Container

Info

Publication number: GB2543074A
Application number: GB1517741.3A
Authority: GB
Inventors: Hardwick Craig; Davey Alan
Original assignee: Linpac Packaging Ltd
Current assignee: Linpac Packaging Ltd
Priority date: 2015-10-07
Filing date: 2015-10-07
Publication date: 2017-04-12
Also published as: CA3001276A1; GB201517741D0; WO2017060668A1; EP3359466A1; US20180282044A1; AU2016333733A1

Abstract

A packaging system 1 for vacuum skin packaging comprising a container 2 and a support 3 for the product to be packaged, a vacuum reservoir (4, fig. 5A) being formed between the support and the container. The creation of the vacuum chamber may be aided by positioning means which hold the preferably flat support at a distance from the base 5 of the container. These may be ribs 8, recesses 9 or positioning platforms on one or more side walls 6 of the container or ribs 7 and/or platforms (12, fig. 6) on the base of the container. The container is preferably made of PET, recycled PET, PP, PE, PS and/or EPS, more preferably comprising PET/PE, PET/PEP, rPET/PE or rPET/PEP layers and shaped to be stackable with other containers of the same type. The support may further be perforated (14, fig. 11) to facilitate the drawing of any exudate from e.g. a packaged food product into the vacuum reservoir. The thermoplastic film which is placed over the container in the process of vacuum packaging may be made from polyethylene, an ethylene copolymer and/or a gas-moisture barrier material and preferably comprises a sealing layer and a peelable layer.

Description

CONTAINER

The present invention relates to containers suitable for use in the packaging, storage, transportation and/or display of a product, such as a fresh food product, and to processes for making such containers. More particularly, the present invention relates to containers for the vacuum skin packaging of products and corresponding processes.

It is known to use plastic containers to package, store, transport and display fresh food. These containers may be sealed with a lidding film to protect the food within the container from the surrounding environment. Additionally, the atmosphere within such containers may be modified to enhance the shelf life and/or appearance of the fresh food within the container.

Alternatively, the products can be packaged by way of known vacuum packaging processes. For example, vacuum skin packaging processes are widely used for packaging fresh products such as meat, poultry, fish, cheese and the like. The product is typically placed on a support; a film is positioned above the product and heated; the air between the product and the film is evacuated and vacuum is applied so that the film contacts the product and the support thereby forming a tight “skin” around the product and a seal with the support. Vacuum skin packaging usually increases the shelf life of fresh products.

It has also been observed, both in conventional containers and in vacuum packaging, that juices exuded by products, such as blood from meat, remain in contact with the product and, as well as being unsightly, affect its quality and freshness. Absorbent pads can be inserted and although the exudates are absorbed, they remain in contact with the product. Other packaging designs have been developed wherein the exudates is isolated from the products (for example in EP 2 540 642 and US 7,921,992) but these packaging often have intricate designs, which complicate the manufacturing processes and increase the associated costs.

It is an object of the invention to at least alleviate the above-mentioned disadvantages, or to provide an alternative to existing products.

According to a first aspect of the invention, there is provided a process for packaging a product comprising the step of creating a vacuum reservoir in a container. The vacuum reservoir can take up the liquids exuded from the product as well as any gases arising from the aging of the product to maintain a desired level of vacuum within the pack. This can increase the shelf life of fresh products when compared to conventional vacuum packaging systems as well as improve organoleptics and eating quality.

In a preferred embodiment, the process comprises the steps of positioning a support for the product into a container so as to create a reservoir; placing the product onto the support; placing a thermoplastic film over the container; and removing the air between the container and the film.

Preferably, the process further comprises the step of lifting and heating the film above the container. For example, the film is drawn upwards by vacuum to form a dome shape above the container and heated to soften the material of the film.

Preferably, the process comprises the step of applying vacuum so that the film contacts the product and the support.

Preferably, the process comprises the step of applying vacuum so as to create a vacuum reservoir between the support and the container. The air is removed from the container and the film is sucked downwards onto and around the product and onto the upper surface of the support.

Preferably, the container comprises a base and one or more side walls extending from the base. This feature is particularly advantageous in that the container provide rigidity and protection to the packaged product. In addition, it facilitates the packaging, handling, transport and display of the packaged product. The base of the container may be substantially rectangular, square, or circular or any shape suitable for the intended use.

The packaging system according to the present invention may be a two-part system comprising a container and a support, which are detachably coupled. The support can be inserted and positioned into the container so as to create a space between the base of the container and the lower surface of the support, for a vacuum reservoir. Within the context of the invention, a packaging system in which the container and the support are not detachable and/or integrally formed is also considered.

In a preferred embodiment, the container comprises means for positioning the support within the container. This allows the support to be positioned so as to create a vacuum chamber of suitable dimensions and shape. By controlling the position of the support, the volume and therefore the vacuum capacity of the vacuum reservoir can be adjusted according to the intended use.

Preferably, the container comprises one or more positioning recesses in one or more side walls. For example, the outer edge of the support can be inserted or slotted into one or more recesses so as to be retained in the correct position. Preferably, the container comprises one or more positioning ribs in one or more side walls. More preferably, the support can be slotted and/or retained between two or more ribs. Preferably, the container comprises a positioning platform to support the support above the base of the container. The platform may run along the whole or part of the inner periphery of the side walls. It may be one or more platforms. Preferably, the base of the container comprises one or more positioning ribs. Preferably, the highest portions of the ribs are aligned within a same plane. The highest portion of the ribs preferably comprises a substantially flat surface. Preferably, the ribs extend from the side wall(s) of the container. In addition or alternatively, ribs and/or platforms are located in one or more corners of the container.

Preferably the process comprises the step of applying adhesive onto the positioning means of the container, prior to positioning the support onto the positioning means. The adhesive may be applied by means of one or more rollers to apply a homogenous layer of adhesive, or more preferably using a robot, such as an automated robot, programmed to apply one or more beads of adhesive, which will be flattened by the support in position. In some applications, the use of adhesive is not required.

In a preferred embodiment, the container is nestable and/or stackable with other containers of the same type. The container may comprise one or more features to facilitate the separation of nested or stacked containers, for example denesting recesses. The packaging system of the present invention is therefore easy to store and transport, as the containers can be nested or stacked onto each other. The supports can be provided separately and the system assembled at the point of packaging.

Preferably, the container comprises or consists of a rigid or semi-rigid sheet, suitably formed into the useful container shape. Preferably, the container comprises or consists of one or more thermo-formed thermoplastic materials such as polyethylene terephthalate (PET), recycled polyethylene terephthalate (rPET), polypropylene (PP), polyethylene (PE), polystyrene (PS), expanded polystyrene (EPS), each of which can have various advantages in terms of recyclability, recycled content, rigidity, gas barrier properties, visual appearance and the like. Other preferred materials include PET/PE, PET/PEP, rPET/PE and rPET/PEP layers. Containers comprising a layer of polyethylene peelable (PEP), such as PET/PEP or rPET/PEP layers are preferred in peelable applications, whereas PET/PE or rPET/PE layers are preferred for lock-sealed but non-peelable applications.

Preferably the container and/or the support comprise of a polyethylene surface layer (or liner) to improve the sealing characteristics of the skin film to the tray and provide a seal that can be easily peeled during opening. A preferred material for the container is PET, which provides an efficient barrier to gas and prevents the loss of vacuum. Thus, the container may comprise or consist of PET.

Preferably the liner (food contact side) has good sealing properties and for example comprises or consists of PE or a modified PE material with peelable properties brought about by techniques known in the art.

Preferably, the skin film comprises material combinations known in the art that give good skinning performance including but not limited to puncture resistance, high gas barrier, good conformability to complex product shapes, good sealing properties with lock-seal and peelable tray substrates. In addition, the skin film preferably comprises a gas barrier layer (for example oxygen and/or carbon dioxide barrier) to prevent loss of the vacuum.

The support may be a substantially flat insert. The outer perimeter of the support may have substantially the same shape as the inner perimeter of the container. The outer perimeter may have slightly smaller dimensions than the same dimensions as those of an inner perimeter of the container. The outer perimeter of the support may be such that there is one or more gaps between the outer perimeter of the support and the inner periphery of the container to allow for the passage of gas and/or liquids. The support may have angular or curved comers. The support may be clipped, slotted, placed, glued or otherwise fitted into position.

Preferably, the support comprises one or more apertures and/or perforations. More preferably, the support comprises perforations arranged in a pattern. In addition or alternatively, the support may comprise one or more slits. For example, the slits may be parallel to the longitudinal walls or the lateral walls of a substantially rectangular container. The apertures, perforations and/or slits are such that they allow for the passage of gas and/or fluids.

According to a second aspect of the invention, there is provided packaging system for use in the process as described above, wherein the system comprising a vacuum reservoir.

According to a third aspect of the invention, there is provided a container for use in a packaging system according to the present invention and as defined in any one of the preceding paragraphs.

The invention will be further described with reference to the drawings and figures, in which figures 1 and 2 are schematic representations of a first packaging system according to the present invention, wherein the container and the support are shown prior to assembly; figure 3 is a schematic representation of the packaging system of figures 1 and 2, wherein the container and the support are shown in an assembled configuration; figure 4 is a top view of the packaging system of figure 3; figures 5A and 5B are cross-sectional views of the packaging system of figure 3; figures 6 and 7 are schematic representations of a second packaging system according to the present invention, wherein the container and the support are shown prior to assembly; figure 8 is a schematic representation of the packaging system of figures 6 and 7, wherein the container and the support are shown in an assembled configuration; figure 9 is a top view of the packaging system of figure 8; figures 10A and 10B are cross-sectional views of the packaging system of figure 8; and

Figure 11 is a schematic representation of a support for use in a packaging system according to the present invention.

Referring to figure 1, there is illustrated a packaging system 1 comprising a container 2 and a support 3. A vacuum reservoir 4 is illustrated on figures 5A and 5B.

The container 2 comprises a base 5 and side walls 6 extending from the base 5. The container 2 can be manufactured by thermo-forming or injection moulding processes as known in the art. An advantage of the present invention is that the elements of the packaging system 1 are simple to manufacture and little modification to existing manufacturing tools is required. The container 2 consists of or comprises one or more materials and/or layers selected from PET, rPET, PP, PE, PS, EPS, PET/PE, PET/PEP, rPET/PE and rPET/PEP.

One or more, in this case several, ribs 7 formed in the base 5 of the container 2. These ribs 7 have a substantially flat upper surface and form a supporting and positioning platform for the support 3. One or more ribs 8 are formed in the side walls 6 of the container 2. The ribs 8 have a slopped upper surface (relative to the side wall) to facilitate the insertion of the support 3 and a lower surface which is substantially perpendicular to the side wall 6 so as to prevent the support 3 from dislodging itself. Thus, the support 3 is retained between the base ribs 7 and the wall ribs 8. Other configurations may be envisaged. For example, the side walls 6 may comprise recesses, such as recesses formed by two ribs, between which the support 3 can be inserted.

In this embodiment, the container 2 is nestable with other containers of the same type and comprises recesses 9 located adjacent or at one more comers so as to facilitate the separation of nested containers. The container 2 comprises a peripheral flange 10 surrounding the mouth of the container 2 to facilitate handling, packaging, nesting and/or stacking. This is particularly advantageous in the context of the present invention as the vacuum skin packaged products can be stacked onto the flange of another vacuum skin packaged product below, without the product becoming compressed under the weight of the products above.

The support 3 consists of a substantially flat insert with an upper surface 3a for supporting a product (not shown) and a lower surface 3b. In the assembled configuration shown in figures 3 to 5, the vacuum reservoir 4 is defined by the lower surface 3b of the support 3, the base 5 and side walls 6 of the container 2. The support 3 comprises a semi-rigid or rigid material. The support 3 comprises or consists of a rigid or semi-rigid flat sheet or a thermo-formed shaped platform comprising or consisting of a thermo-plastic material such as PET, recycled PET, PP, PS, PE. The simple structure of the support 3 is particularly advantageous for manufacture, transport and handling purposes.

In the preferred embodiment, the support comprises one or more apertures, more preferably a series of perforations (for example a pattern of 24 perforations of 1.5mm diameter). The perforations facilitate both the generation of the vacuum reservoir and the flow of blood and meat juices from the product into the vacuum reservoir. Flow of gas and meat juices can be controlled and adapted by changing the pattern, frequency and size of the perforations.

In another embodiment, the container 2 and the support 3 are integrally formed. Alternatively, in use, the support 3 is coupled to the container 2 is a non-detachable manner. In another embodiment, the support 3 is partly connected to the container 2. For example, the support 3 may be hingedly connected to the container 2.

Figures 6 to 10 illustrate a second packaging system according to the present invention. The system 1 comprises a support 3 with an upper surface 3a and a lower surface 3b, a container 2, and a vacuum reservoir 4. The container 1 comprises a base 5 and side walls 6. The differences between the containers of the first and second packaging system are discussed below.

The container 1 comprises positioning ribs 11 formed in the base 5 of the container 1 and extending from the side walls 6 of the container 1. In addition, the container 1 comprises a positioning platform 12 located at each corner of the container 1. In this embodiment, the positioning ribs 11 and the platforms 12 comprise a substantially flat upper surface for placing the support 3 thereon. The upper surfaces are located within a same place to receive the substantially flat support 3. The support 3 is therefore positioned above but not against the base 5, so as to create a vacuum reservoir 4 between the lower surface 3a of the support 3 and the base 5.

The base 5 of the container 1 comprises absorption features 13 comprises a plurality of recesses and protusions; recesses to receive any fluid seeping from the product and protrusions to direct the fluid towards the recesses. With reference to figure 11, the fluid can seep from the product, through slits 14, into the vacuum reservoir 4. Where the support 3 comprises apertures and/or perforations (not shown), the fluid can seep through said apertures and/or perforations.

In use, a container 2 is formed by a thermo-forming process from a plastics material. The packaging system is assembled by inserting a support 3 into the container 2. Pressure is applied to push the support 2 along the sloped surface of the ribs 8, until the support 2 slots itself between the lower surface of the wall ribs 8 and the upper surface of the base ribs 7.

In the second packaging system as shown in figures 6 to 10, adhesive is applied onto the flat upper surfaces of the positioning ribs 11 and platforms 12 formed in the base 5 of the container 1, prior to positioning the support 3. The adhesive can be applied using an automated robot programmed to drop a bead of adhesive onto the upper surfaces. The use of the adhesive is not always required, as the vacuum combined with the weight of the product also maintain the support 3 into position.

Where the container 1 comprises a positioning platform (not shown) along the inner periphery of the side walls 6, then the support 3 can be placed directly onto the platform or adhesive can be applied onto the platform prior to placing the support 3.

The product is placed on the upper surface of the support 3 and a film (not shown) is placed over the container 2 containing the product and the support 3. The film consists of or comprises a plastics material such as those typically used in other skin packaging applications, for example multi-layer combinations of PE, an ethylene copolymer such as Surlyn® (Dupont™ Ionomer), and one or more gas barrier materials such as EVOH and/or PA.

In a preferred embodiment, the film comprises an outer layer of cross-linked material. This crosslinking process transforms the normally thermo-plastic layers to materials which are semithermosetting in nature. This allows, as one particular benefit, that the outer layer (for example comprising polyethylene) can be in contact with the heating dome of the vacuum skinning apparatus, which may be at up to 240°C, without melting or sticking to that dome as an untreated polymer material normally would.

The film can comprise a moisture-barrier layer or material to prevent moisture loss from the product, in particular meat products. The film can comprise an oxygen-permeable layer or material to prevent the product, in particular meat products, from drying out and to preserve its red colour.

The film is lifted above the container 2, for example by being drawn upwards by applying a vacuum, to form a dome shape above the container 2. The film is heated at temperatures ranging from 160°C to 240°C, which are high enough so that the film material softens. The film is then sucked downwards towards the product and the support, preferably by application of vacuum. Enough vacuum is applied so that (1) the film contacts and partially surrounds the product, (2) the film contacts and adheres to the upper surface 3 a of the support 3 and to the container 2, (3) the air in the vacuum chamber 4 is evacuated, thereby creating a vacuum reservoir. The evacuation of air can be through the apertures, perforations and/or slits 14 formed in the support 3, and/or through any gap between the support 3 and the side walls 6. The product is vacuum skin packaged in a packaging system 1 comprising a container 2.

It has been observed that the shelf life of a product thus packaged is increase up to at least six weeks due to the presence of the vacuum reservoir 4 compared to 1 to 2 weeks for a product packaged in a conventional film-lidded container and 3 to 4 for a product in a conventional vacuum skin packaging without a vacuum reservoir. In addition, any exudate from the product is drawn into the vacuum chamber 4, which further decreases the risk of product degradation and produces a fresher, more appealing appearance.

The present packaging process and system have been found to be particularly advantageous when used for packaging minced meat(s) or products comprising minced meat(s).

Due to its form, minced meat has a tendency to retain air and residual air may remain in the meat after the vacuum stage. In the present invention, this residual air is slowly drawn out of the meat, sucked towards and retained in the vacuum reservoir. Consequently, the shelf life of the mince meat can be further extended.

The present packaging process and system have been found to have unexpected advantages when used for packaging meat products, such as beef. Aged beef can be obtained by a dry-aging process or a wet-aging process. In a dry-aging process, beef is hung or placed on a rack to dry for several weeks under specific conditions. Once the meat has lost enough moisture, the dry crust is trimmed off and discarded. By this process, up to half of the original meat weight can be lost through drying and trimming. In a wet-aging process, the meat is typically aged in a vacuum sealed bag to retain its moisture. Generally, dry-aged beef is considered to have superior taste compared to wet-aged beef. Wet-aged beef obtained using the packaging system according to the present invention has been found to have dry-aging taste characteristics, without the associated weight loss.

Thus, from the above description, it can be seen that the present invention provides a process and packaging system which increases the shelf-life and improves the eating quality of fresh products. This is achieved through the use of a vacuum chamber. The packaging system is simple to manufacture, to use and to transport and combines an extended shelf life compared to conventional vacuum skin film packaging with the presentation and protection benefits of rigid or semi-rigid containers.

Claims

1. The packaging system for vacuum skin packaging a product, wherein the packaging system comprises a container and a support arranged and configured to create a vacuum reservoir.

2. The packaging system according to claim 1, wherein the container comprises a base and one or more side walls extending from the base.

3. The packaging system according to any one of claims 1 or 2, wherein the container comprises means for positioning the support to create a vacuum reservoir.

4. The packaging system according to claim 3, wherein the container comprises one or more recesses in one or more side walls.

5. The packaging system according to claim 3 or 4, wherein the container comprises one or more positioning ribs in or more side walls.

6. The packaging system according to claim 5, wherein the support can be retained between two or more ribs.

7. The packaging system according to any one claims 3 to 6, wherein the container comprises a positioning platform along one or more side walls.

8. The packaging system according to any one claims 3 to 7, wherein the base of the container comprises one or more positioning ribs and/or platforms.

9. The packaging system according to any preceding claim, wherein the container comprises or consists of one or more materials selected from PET, rPET, PP, PE, PS and EPS.

10. The packaging system according to claim 9, wherein the container comprises or consists of PET/PE, PET/PEP, rPET/PE or rPET/PEP layers.

11. The packaging system according to any preceding claim, wherein the container is nestable and/or stackable with other containers of the same type.

12. The packaging system according to any preceding claim, wherein the support is substantially flat.

13. The packaging system according to any preceding claim, wherein the support comprises one or more apertures, perforations and/or longitudinal slits.

14. A packaging system according to any preceding claim, wherein the system comprises a vacuum reservoir.

15. A container as defined in any one of the preceding claims.

16. A process for packaging a product comprising the step of creating a vacuum reservoir in a container.

17. The process according to claim 15, comprising the steps of a. positioning a support for the product into a container so as to create a reservoir; b. placing the product onto the support; c. placing a thermoplastic film over the container; and d. removing the air between the container and the film.

18. The process according to claim 16, comprising the step of lifting and heating the film above the container prior to the application of vacuum.

19. The process according to claim 16 or 17, comprising the step of applying vacuum so that the film contacts the product and the support.

20. The process according to any one of claims 16 to 18, comprising the step of applying vacuum so as to create a vacuum reservoir between the support and the container.

21. The process according to any one of claims 16 to 19, wherein the film comprises one or more materials selected from PE, an ethylene copolymer, a gas and/or moisture barrier material.

22. The process according to any one of claims 16 to 20, wherein the film comprises a sealing layer and/or a peelable layer.

23. A packaging system as described herein with reference to the accompanying drawings and/or examples

24. A container as described herein with reference to the accompanying drawings and/or examples.

25. A process for packaging a product as described herein with reference to the accompanying drawings and/or examples.