WO2008139168A1

WO2008139168A1 - Multi-compartment pack and method of forming the pack

Info

Publication number: WO2008139168A1
Application number: PCT/GB2008/001624
Authority: WO
Inventors: James Patrick Dale
Original assignee: Rpc Containers Limited
Priority date: 2007-05-10
Filing date: 2008-05-09
Publication date: 2008-11-20
Also published as: GB0919618D0; GB0709040D0; GB2463997B; GB2463997A

Abstract

A multi-compartment pack (10) comprises a plurality of containers (20, 30), wherein each container is formed, filled and sealed separately before the containers are joined together to form the pack. The containers (20, 30) may be filled with different food products, which require different forms of treatment after the container is sealed. In a preferred method, the containers are filled and sealed at different sites, subjected to different processing treatments, and then brought together to form the multi-compartment pack at a further site.

Description

MULTI-COMPARTMENT PACK AND METHOD OF FORMING THE PACK

The invention relates to a package, and more particularly to a pack comprising two or more containers, which are initially formed separately and subsequently joined together. The invention also relates to a method for producing the pack.

So-called "twin-pot" containers are well known. Such containers typically have two separate compartments, which can for example contain different foodstuffs. A well-known example, at least in the United Kingdom, is the Mϋller "Corner" range, in which a compartment containing yoghurt is integrally formed with a smaller compartment for fruit compote or the like.

The compartments are integrally formed, and sealed by a single membrane seal. Thus, both compartments must be filled before the container can be sealed, and so the compartments are usually filled on the same production line. If the compartments are to be filled with different products, then the production line must include means for supplying both products, which can increase plant costs.

Further, since the compartments are integrally formed, any treatment applied to one of the filled compartments will inevitably be applied to the other filled compartment. For example, it is not possible to have one compartment containing a product which needs to be retorted, and to have the other compartment containing a cold-fill product. This limits the range of the products which can be used with such a container.

Similarly, even if only one of the products requires a barrier layer, then it is necessary to form both compartments with a barrier layer, which can increase the cost of the pack.

According to a first aspect of the invention, there is provided a method of forming a multi-compartment pack, comprising the steps of: forming each compartment as a separate container; filling each container so formed; sealing each filled container; and joining the containers together to form said multi-compartment pack.

Since the containers are filled and sealed before they are joined to each other, each container can receive a different treatment, appropriate to its contents, before the completed multi-compartment pack is formed. This increases the range of products which can be supplied in the multi-compartment pack.

The containers can include any product, and the pack is particularly suited to products which must be kept separate until use (for example, epoxy adhesives). However, it is preferred for the containers to be filled with food products, and more particularly for each container to be filled with a different food product. Each food product can then receive an appropriate treatment after filling.

In a particularly preferred method, each container is filled with product at a different site, and after the containers are sealed, they are joined to each other at a further site to form said multi-compartment pack. This further site may be one of the sites at which filling took place, or may be a different site altogether.

Preferably, the containers are joined together by welding, preferably ultrasonic welding. Such a joining method is simple and cheap, and does not affect the contents of the containers.

In a preferred form, after the containers are filled and sealed, at least one of the containers is subjected to heating. This can serve, for example, to cook a food product in the container, and by using the method of the invention, only the food products contained in the pack that require cooking are cooked.

According to a second aspect of the invention, there is provided a multicompartment pack, comprising a plurality of containers joined together, wherein each of said plurality of containers is formed, filled and sealed separately before the containers are joined together. The same advantages as those discussed above with regard to the method accrue to the pack.

The containers may contain different food products, hi this case, it is preferred that the compartment(s) which contain food that requires a barrier layer is/are provided with a barrier layer, and the compartments) which contain food that does not require a barrier layer is/are not provided with a barrier layer. This can reduce the cost of the pack, as it avoids the unnecessary use of barrier materials.

The pack can have any number of compartments, but for the sake of simplicity, it is preferred for the pack to have two compartments. If the pack has three or more compartments, then two or more of the compartments could be filled with the same product; there is no need for all of the compartments to be filled with a different product.

The invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first container which will form a first compartment of a pack;

Figure 2 is a cross-sectional view of the first container;

Figure 3 is a detail cross-sectional view of a part of the first container (circled in Figure 2);

Figure 4 is a perspective view of a second container, which will form a second compartment of a pack;

Figure 5 is a cross-sectional view of the second container; Figure 6 is a perspective view of the first and second containers when connected to form a pack;

Figure 7 is a cross-sectional view of the first and second containers when connected to form a pack; and

Figure 8 is a flowchart showing a preferred method of forming a multicompartment pack.

As best shown in Figures 6 and 7, a pack 10, which may contain food products, consists of two containers 20, 30 joined together. In the Figures, the containers are of differing sizes, but this need not be the case. Further, although Figures 6 and 7 show the containers as being open, it will be appreciated that the pack as sold will have a covering on its upper surface to seal it, described in more detail later.

The first (in this case, larger) container 20 is shown in more detail in Figures 1 to 3. As can be seen from these Figures, the container is generally square in plan view. The sides of the container slope inwards, such that the base of the container is smaller that the opening at the top. This allows containers to be nested within each other, to reduce the amount of storage space required to store the containers.

Around the edge of the container is an outwardly protruding lip 22. At one side of the container, the lip is formed with an upwardly open recess 24 at its edge (as best shown in Figure 3). Further, a groove 26 is formed in the underside of the lip 22, between the recess 24 and the body of the container. This groove 26 allows separation of the connected containers, as will be discussed in more detail later.

The second (in this case, smaller) container 30 is shown in more detail in Figures 4 and 5. The second container is generally rectangular in plan view, with the length of the long side of the second container being roughly equal to the length of the side of the first container which has the recess. As with the first container, the sides of the second container slope inwards to allow the containers to be nested.

Again, a protruding lip 32 is formed around the edge of the second container. The thickness of the lip 32 is roughly equal to the depth of the recess 24 on the first container 20, such that the lip 32 can be accommodated in the recess 24.

The two containers 20, 30 are formed separately, and any suitable method may be used to form the containers. One particularly suitable method is thermoforming.

This separate formation of the containers allows them to be filled separately, and so products which require different filling regimes can be filled into each container. For example, one container could be filled with a food product that needs to be cooked in the container, while the other container could be filled with a cold- fill product. After each container is filled, it is closed using a membrane seal, and the closed container can then be subjected to any necessary treatment (for example, to cook the food product).

The two containers 20, 30 can then be joined as a final step in the production of the pack 10. This connection is preferably done through ultrasonic welding. The lip 32 of the smaller container 30 is positioned in the recess 24 of the larger container 20, and the containers 20, 30 are welded together to form a single "twin- pot" pack 10. It has been found that the weld is secure even when the membrane covering of the larger container is trapped between the recess 24 and the lip 32.

Although the drawings show the weld as being a single straight line, other geometries could of course be used. Further, methods other than welding (for example, gluing with a suitable glue) could be employed to join the containers.

The groove 26 formed in the underside of the Hp 22 on the larger container 20 allows the two containers 20, 30 to separated from each other after welding. The groove forms a line of weakness, and the pack 10 can be flexed along this line to break the two parts away from each other. This allows the contents of the smaller container 30 to be poured into the larger container 20, to allow the products to be mixed.

Further, as the compartments are formed separately, it is possible to avoid the unnecessary use of barrier layer. If only one of the products requires the use of barrier layer, then the container containing that product (and the membrane seal, if appropriate) can contain a barrier layer. However, as the other product does not require a barrier layer, there is no need for the other container to be formed with a barrier layer. This can reduce the costs of the completed pack.

Furthermore, it should be noted that as the containers are formed separately, they need not be filled at the same time, or the same place. It is possible (and indeed preferred) for the containers to be filled in different plants at different times, and transported to where they will be joined to each other (which could be one of the plants where filling took place). Thus, the pack of the invention allows a more _N flexible production process.

A currently preferred form of the production process for a two-compartment pack will now be described with reference to Figure 8.

A first container and a first food product are provided at a first site, and a second container and a second food product are provided at a second site. Although it is possible for the first and second containers to be manufactured on-site, it is expected that the containers will be formed at a forming plant and-transported to the first and second sites.

The first container is then filled with the first product and sealed, and the second container is filled with the second product and sealed. As the filling processes take place at different sites, different filling processes (for example, hot- filling and cold-filling) can be used for each container. The sealed containers are then subjected to any necessary treatment (for example, retorting); again, as the filling processes take place at different sites, the first and second containers can be subjected to different treatments without any difficulty.

- The filled and sealed first container and the filled and sealed second container are then brought together at the same site. This could involve transporting the second containers to the first site, or transporting the first containers to the second site; it is also possible that the first and second containers will be transported to a third site, where the necessary welding and packaging machinery can be provided.

As the containers are sealed, there is no risk of contamination from the products contained in the containers. This is particularly useful if one of the products can cause an allergic reaction, such as peanuts. Normally, to reduce the risk of potentially dangerous allergic reactions from cross-contamination, products which do not contain nuts are produced and packaged in an entirely nut-free environment; however, it is then not possible to produce any finished products containing nuts in this environment. If, however, the nut-containing product is supplied already sealed in a container, then the same plant can be used to produce nut-free and nut-containing products.

After the first and second containers are brought to the same site, they are welded together to form a multi-compartment pack. The welded pack may be wrapped or otherwise packaged to make it ready for distribution and sale.

Although the above description has been in the context of a two- compartment pack, it will be appreciated that the invention allows packs with three (or more) compartments to be formed.

Claims

1. A method of forming a multi-compartment pack, comprising the steps of: forming each compartment as a separate container; filling each container so formed; sealing each filled container; and joining the containers together to form said multi-compartment pack.

2. A method as claimed in claim 1 , wherein each container is filled with a food product.

3. A method as claimed in claim 2, wherein each container is filled with a different food product.

4. A method as claimed in claim any preceding claim, wherein each container is filled with product at a different site, and after the containers are sealed, they are joined to each other at a further site to form said multi-compartment pack.

5. A method as claimed in any preceding claim, wherein the containers are joined together by welding, preferably ultrasonic welding.

6. A method as claimed in any preceding claim, wherein after the containers are filled and sealed, at least one of the containers is subjected to heating.

7. A multi-compartment pack, comprising a plurality of containers joined together, wherein each of said plurality of containers is formed, filled and sealed separately before the containers are joined together.

8. A pack as claimed in claim 7, wherein the containers contain different food products.

9. A pack as claimed in claim 8, wherein the compartment(s) which contain food that requires a barrier layer is/are provided with a barrier layer, and the compartment(s) which contain food that does not require a barrier layer is/are not provided with a barrier layer.

10. A pack as clamed in any of claims 7 to 9, wherein the pack has two compartments.

11. Containers for forming a pack as claimed in any of claims 6 to 10.