The current invention relates to an injection moulded container which is suitable for food products and which comprises portions of recycled plastic materials.

Description of related art There is currently large public interest in reducing the amount of waste from plastic packaging. One way to reduce plastic packaging waste, is to recycle more plastic. Recycled plastic is already often used in different plastic products, including plastic packaging. However, when making plastic packaging which is suitable for containing food products, specific requirements are made to the recycled material to ensure user safety.

In particular, regulations say that any material which is in contact with food, must be a food grade material. However, when acquiring generic recycled plastic material which is suitable for injection moulding, it is difficult to ensure that all the material is food grade ready as it is not certain where the material comes from. For example, many cities have implemented plastic recycle bins, but it cannot be certain what the users put into their recycle bins. Recycled material therefore needs to be cleaned and or treated such that it is free of any potential contaminants prior to being used in packaging for food products. This increases the cost of the material thereby making it less suitable for low cost injection moulded containers. Also, at the current time, the amount of available food grade certified recycled plastic material is not very high. This also adds to the cost. Furthermore, for typical food containers, it is often desired to use Poly Propylene (PP). There is a lot of recycled PP material on the market, but it is used for all sorts of other products and it is expensive to treat to make it food grade certified. It is therefore difficult and expensive to get a hold of food grade certified recycled PP Summary of the invention

It is therefore a first aspect of the current invention to provide a plastic packaging as mentioned in the opening paragraph which has a reduced cost in comparison to prior art solutions.

A second aspect of the current invention is to provide a plastic packaging as mentioned in the opening paragraph which has a simple manufacturing process. A third aspect of the current invention is to provide a plastic packaging as mentioned in the opening paragraph which allows for many different forms.

These aspects are solved at least in part by an injection moulded container comprising a bottom, a sidewall extending upwardly from the bottom and an upper rim defining a container opening arranged at the upper edge of the sidewall, said container comprising an inner functional barrier layer and a first injection moulded portion, said inner functional barrier layer comprising a bottom portion and a side wall portion and said first injection moulded portion comprising a side wall portion and an upper rim portion, said first injection moulded portion being injection moulded from a food grade plastic material and being injected in a first injection moulding step to join to the inner functional barrier layer such that the inner functional barrier layer and the first injection moulded portion together provide a sealed inner surface of the injection moulded container where the container further comprises a second injection moulded portion, said second injection moulded portion being injection moulded in a second step, being arranged outside the inner functional barrier layer and comprising a recycled plastic material. In this way, a large portion of the container can be made from non food grade recycled material.

According to food safety regulations, recycled materials which are not food grade certified may be used in food containers if they are kept separated from food contact by a functional barrier layer.

The functional barrier layer could be provided by many different types of functional barrier materials as will be known to the person skilled in the art. The term functional barrier material should, in the context of the current invention, be understood as a material which prevents undesired chemicals contained in the recycled plastics material of the second layer from wandering out of the recycled plastics material and through the layer with the functional barrier material in a quantity which is undesirable. Depending on the degree of contamination or risk of contamination of the recycled plastics material, the functional barrier material could be different types. In a case where a light contamination is present, a rather simple functional barrier material could be provided. In a case where a more significant contamination is present, a stronger functional barrier material would be needed.

One typical functional barrier material would be ethylene vinyl alcohol (EVOH). Another material could be PolyEster or Polyethylene terephthalate (PET). Another example could be a foil with an aluminium barrier layer. This could be a flexible film coated with Aluminium Oxide (AIOx). Other suitable films with or without suitable coatings or layers will also be known to the person skilled in the art. However, in certain cases, it might be enough to just provide a clean layer of plastic, for example Polypropylene (PP), on one or both sides of the recycled plastics material layer. The person skilled in the art will be able to test if a potential barrier material is suitable when considering the food product and the degree of contamination of the recycled material of the second layer.

In the plastic packaging industry, specifications of the functional barrier properties will be made for different applications and for different recycled plastic materials. The person skilled in the art will then be able to choose a functional barrier material and its dimensions which fulfil the demands for a specific application. As such, in the current specification, no specific limits will be provided for the functional barrier properties, as it will be dependent on a case by case analysis and should easily be provided by a person skilled in the art.

In one embodiment, the inner surface of the container is provided by the exposed surfaces of the inner functional barrier layer and the first injection moulded portion.

In one embodiment, the inner functional barrier layer is provided as one or more foil elements which are folded and/or assembled into a container like shape with one or more gaps and/or one or more overlapping areas between adjacent portions of the one or more foil elements and in that the first injection moulded portion is arranged to fill the one or more gaps and/or cover the one or more overlapping areas. In this way, the gaps in the barrier material are filled by a clean material. It should be noted that in certain cases, the barrier layer should overlap the clean material a certain amount to ensure that contaminants in a material located adjacent the clean material does not wander through the clean material and onto the exposed surface of the clean material. Hence, it will be typical that the barrier layer overlaps the clean material a certain distance. In one embodiment, the certain distance could be at least 1 times the thickness of the container, or at least 2 times the thickness of the container or at least 3 times the thickness of the container. Likewise, in certain cases, the barrier layer can be arranged such that it overlaps itself to reduce the gap between adjacent portions of the barrier layer. However, even in these cases, in some applications it will be desireable to cover these overlapping areas with clean material to further reduce the risk of contaminants in the recycled material from passing through the overlapping areas of the barrier layer.

In one embodiment, the foil elements are made from a flexible foil element. In one embodiment, the foil elements are made from a material which bonds to the material of the first injection moulded portion during the injection moulding process.

In one embodiment, the first injection moulding material could comprise multiple different materials which are co-injected. In this case multiple materials are injected simultaneously via an injection nozzle to form an outer skin and an inner core. In this case, the inner core could be made of a barrier material or of an oxygen scavenger material.

In one embodiment, the container further comprises an outer foil layer. In one embodiment, the outer foil layer is a decorative In Mould Label (IML).

In one embodiment the outer foil layer is a functional barrier layer. In one embodiment, the outer foil layer is made from a flexible foil material. In one embodiment, the outer foil layer comprises a layer of a plastic foil material. In one embodiment, the outer foil layer has a layer made from a material which bonds to the material of the second injection moulded portion during the injection moulding process. In one embodiment, the outer surface and the inner surface of the outer foil layer are made from materials which bond together when overlapped and heated in an injection mould. In one embodiment the outer foil layer comprises a first portion which covers a first portion of the second injection moulded portion, covers a first portion of the first injection moulded portion and covers a second portion of the outer foil layer and/or a second portion of the second injection moulded portion. This should be understood in a way such that the named first portion of the outer foil layer extends across a portion of the first injection moulded portion so that it attaches to the second injection mould portion on both sides of the first injection moulded portion. It should be noted that in most cases, the first injection moulded portion will be cooled by the time the outer foil layer is added. Hence, the outer foil layer will not attach so well to the first injection moulded portion and having it extend across the first injection moulded portion so that it can attach to the second injection moulded portion on both sides of the first injection moulded portion ensures that the outer foil layer is firmly attached to the container without any loose edges. Instead of attaching to the second injection moulded portion, the outer foil layer can also attach to itself if the inner and outer layers of the outer foil layer can join together when heated.

In another embodiment, a layer of adhesive could be applied to the outer surface of the first injection moulded portion prior to applying the outer foil layer to the first injection moulded portion.

In one embodiment, the container has a rectangular form with four rectangular sidewall portions connected by four side edge portions and in that the inner functional barrier layer covers the sidewall portions and in that the first injection moulding portion is exposed on the inside of the container at the four side edge portions. In one embodiment, the second injection moulded portion is arranged outside the inner functional barrier layer and between adjacent portions of the first injection moulded portion. The above mentioned aspects are also solved at least in part by a method of manufacturing an injection moulded container, said method comprising the steps of: (a) providing a first injection moulding station comprising a first injection mould cavity, (b) providing an injection mould core at the first injection moulding station, (c) providing an inner foil with functional barrier properties, (d) placing the inner foil on the injection mould core, (e) closing the first injection mould cavity with the injection mould core, (f) injecting a food grade injection moulding material into the closed first injection mould cavity to form a first injection moulded portion which is bonded to the inner foil, (g) opening the first injection mould cavity, (h) providing a second injection moulding station comprising a second injection mould cavity, (i) providing an injection mould core at the second injection moulding station, (j) moving the first injection moulded portion and the inner foil from the first injection moulding station to the second injection moulding station, (k) arranging the first injection moulded portion and the inner foil on the injection mould core or in the second injection mould cavity, (I) closing the second injection mould cavity with the injection mould core, (m) injecting a second injection moulding material into the closed second injection mould cavity, said second injection moulding material comprising a recycled plastic material, (n) opening the second injection mould cavity, and (o) removing the injection moulded container from the second injection mould cavity.

By manufacturing the container in two steps, two different materials can be used, a clean material in a first step which together with the barrier label forms an inner layer of the container and a potentially contaminated material in a second step where an outer layer is formed. It should be noted that the “clean” inner layer could be the innermost surface of the container, or additional coatings/films/foils could be further applied. Likewise, it could be that the potentially contaminated material could form a part of the outer surface of the container, or additional coatings/films/foils could be further applied. However, the second injection moulded material will be located outside the inner foil.

In one embodiment, the steps of providing a mould core at the second injection moulding station, moving the first injection moulded portion and the inner foil from the first injection moulding station to the second injection moulding station and arranging the first injection moulded portion and the inner foil on the injection mould core comprise the step of moving the injection mould core from the first injection moulding station to the second injection moulding station without removing the first injection moulded portion and the inner foil from the injection mould core. In this way, instead of first removing the moulded part form the injection mould core, moving it and then applying it to another injection mould core, by moving the injection mould core itself, a much faster process can be implement.

In one embodiment, the injection mould core used at the first injection moulding station is the same as the injection mould core used at the second injection moulding station. In one embodiment, the first injection moulding station comprises a first injection mould core and the second injection moulding station comprises a second injection mould core. In one embodiment, the first injection mould core and the second injection mould core are identical. In one embodiment, the method comprises the step of moving the first injection mould core to the second injection moulding station and the step of moving the second injection mould core to the first injection moulding station. In another embodiment, the method comprises the further step of moving the first injection mould core back to the first injection moulding station and moving the second injection mould core back to the second injection moulding station.

In one embodiment of the method, the method further comprises the step of adding an outer foil to the second injection mould cavity prior to closing the second injection mould cavity. In one embodiment of the method, the outer foil comprises functional barrier properties. In one embodiment of the invention, the step of providing the outer foil comprises the step of providing an outer foil in the form of a label having a first portion which overlaps a second portion of the label when it is placed in the mould cavity.

In one embodiment, the step of injecting the food grade injection moulding material into the injection mould cavity includes injecting the food grade injection moulding material into the injection mould cavity via more than one injection nozzle. In one embodiment, the food grade material is injected via four injection nozzles, one injection nozzle located at each corner of the container. In one embodiment, the nozzles are located along a bottom surface of the container. In one embodiment, the nozzles are located at the rim portion of the container. In one embodiment, the rim portion comprises a skirt portion extending outwardly and downwardly from the upper edge of the rim portion and in that the injection points of the nozzles are located on the inside surface of the skirt portion.

It should be emphasized that the term "comprises/comprising/comprised of" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Brief description of the drawings

In the following, the invention will be described in greater detail with reference to embodiments shown by the enclosed figures. It should be emphasized that the embodiments shown are used for example purposes only and should not be used to limit the scope of the invention. Figure 1 shows a perspective view of a first embodiment of a container according to the current invention.

Figure 2 shows an exploded view of the container of figure 1.

Figure 3 shows a perspective view of a second embodiment of a container according to the current invention.

Figure 4 shows an exploded view of the container of figure 3.

Figure 5 shows a schematic representation of a first apparatus to make a container according to the current invention.

Figure 6 shows a partial schematic representation of a second apparatus to make a container according to the current invention.

Figure 7 shows a schematic representation of a third embodiment of a container according to the current invention showing details of one step of the manufacturing method.

Detailed description of the embodiments

The container 1 of figures 1 and 2 comprises a functional barrier layer in the form of a barrier foil 2, a first injection moulded portion 4 made from a food grade plastic material and a second injection moulded portion 6 made from a recycled and potentially non-food grade plastic material.

As can be seen from the figures, the inner surface 8a, 8b, 8c, 8d, 9a, 9b, 9c, 9d of the sidewall of the container and inner surface 10 of the bottom of container which would be in contact with food material in the container, are made from either the barrier foil 2 or the food grade material of the first injection moulded portion 4. Also, the upper rim 12 of the container is made from the food grade material 4. The recycled material 6 will therefore not come into direct contact with food material placed in the container during use of the final container as it is hidden behind the barrier foil 2 and the food grade material 4.

In this embodiment, the container is a rectangular container with four sidewall portions 8a, 8b, 8c, 8d connected by side edge portions 9a, 9b, 9c, 9d. As can be seen from the figures, there is a gap 3a, 3b, 3c, 3d between adjacent sidewall portions of the inner barrier foil 2. The material of the first injection moulded portion fills these gaps at the side edge portions 9a, 9b, 9c, 9d. A portion of the barrier foil 2 will overlap 11 with the first injection moulded portion.

To manufacture the container of figure 1 , in a first step, the inner barrier foil layer 2 is prepared as a blank via a cutting process. In a second step, the inner barrier foil layer is applied on a mould core. In this embodiment, the barrier label comprises a bottom portion 10 and four rectangular sidewall portions 8a, 8b.8c, 8d. The foil can be applied to the core on the bottom portion and then the sidewall portions can be folded up. In other cases, depending on the shape of the container, the inner barrier foil layer could be folded or otherwise formed, either prior to being applied on the mould core, or during application to the mould core. In a third step, a first mould cavity is joined with the mould core to close the mould. Food grade plastic material is then injected into the mould to form the first injection moulded portion 4. The mould is then opened.

In one embodiment of the method, the newly injection moulded part is maintained on the mould core. The mould core is then moved over to a second mould cavity. The mould core is then joined with the second mould cavity and recycled material is injected into the second mould cavity. The second mould is then opened and the finished container removed from the mould.

In another embodiment of the method, instead of moving the mould core, the newly injection moulded part is removed from the mould core after the first moulding operation. The newly injection moulded part is then moved over to a second moulding station. The part is then inserted into a second mould cavity or placed on a second mould core and the mould closed and then injected with recycled plastic. This type of double injection moulding operations is known in the art of injection moulding as“Over moulding”. The technique will not be described in great detail here, as the person skilled in the art is well versed in the art of over moulding.

In both methods as described above, the plastic is injected via a single injection nozzle, in the bottom surface of the mould cavity. Plastic material will then flow into the cavity from this central location and fill channels 13 in the bottom portion and then the side edges 9a, 9b, 9c, 9d and then the rim portion 12.

Figures 3 and 4 show another embodiment of a container 20 according to the invention. In this example, the container also comprises an inner functional barrier layer 22, a first injection moulded portion 24 made from a food grade material and a second injection moulded portion 26 made from a recycled material. However, in contrast to the first embodiment, this second embodiment also has an outer functional barrier layer 28 also in the form of a barrier foil 28.

The outer functional barrier layer 28 ensures that when empty containers are stacked one inside the other, the outer surface of the second injection moulded portion of an upper container will not come into contact with the “clean” inner surface of a lower container. This ensures that contaminants in the recycled plastic material, cannot wander from the recycled material of the upper container to the inner surface of the lower container which will later come into contact with food contents.

It should in this case be noted, that since the time period in which the container will be stacked is often times well known and since the points of contact between the stacked containers can also be determined, it could be that it is not necessary to cover the entire outer surface of the container and/or the required barrier properties of the outer barrier layer could be less than those of the inner barrier layer. For example, in some cases a simple In Mould Label with a simple food grade PP layer arranged on the outside of the container might be enough to satisfy the requirements for a barrier material. This is true if potential contaminants will not be able to wander through the outer layer in a risky amount in the time in which there is contact between the stacked containers.

An additional benefit of using an outer functional barrier layer in the form of a foil, is that the outer layer could also be provided with decoration and function as an in mould label (IML). In certain cases, it might be desired to have the decoration provided by an IML, but it might not be necessary to have functional barrier properties in the IML.

In the embodiment shown in figures 3 and 4, the outer barrier layer is formed as a butterfly label. In particular, the portions of the outer barrier layer which wrap around the side edges of the container are formed to be longer than in prior art applications. In this way the outer barrier layer portions will overlap in a region 30 such that the label will bond to itself during the step of injection moulding the second injection moulded portion 26. In traditional situations where an outer butterfly In Mould Label is used, the side edge portions of the label will bond to the injection moulded material during the injection moulding operation. However, in the current situation, the side edge portions of the container are formed from a food grade material which was formed in a previous injection moulding operation. Hence, this material will be“cold” and the label might not bond to this material properly. Hence, in the current situation, the side edge portions of the label are made longer, so that they overlap other portions of the label. Hence, one portion of the label will be bonded to a portion of the recycled material, and another portion of the label will overlap this portion and join to itself. In another embodiment, instead of overlapping itself, the label could just overlap the portion of the first injection moulded material and reach a portion of the recycled material on the other side of the first injection moulded material. In this case, there would still be some exposed recycled material on the outer surface of the container, however, by placing it in a position in which it does not come into contact with other containers during stacking, this might be okay.

As can be seen from figures 3 and 4, when the container is finished, the recycled material is not directly exposed anywhere on the container. All the recycled material 26 is covered by either the inner barrier layer 22, the food grade material 24 of the first injection moulded portion or the outer barrier Iayer28 . Even the corner portions 32 of the side edge portions which are exposed through the holes 34 in the outer label 28 are made from the food grade material.

In this second embodiment, the method would further comprise the step of adding an outer barrier foil to the second mould cavity, prior to injecting the second injection moulding material.

It should also be noted that in this second embodiment, an outer barrier layer was added to cover the situation where the containers are stacked. However, depending on the design of the containers, it could be ensured that the points of contact between stacked containers only occurs in the food grade certified areas. For example, in one situation, it could be imagined that only the bottom corners or the side edges of the container are in contact with a lower container when stacked. As these areas are made from a food grade material, there is no danger of migration of contaminants between the recycled material and the clean inner surface. In another example, the upper rim of the container is also made from a clean material. As is known in the art, stacking features can be added to the upper rim, so that the only point of contact between stacked containers occurs at the upper rim.

In another embodiment, not shown, one or more outer channel(s) could be formed in the outer surfaces of the side edge portions of the food grade material of the container in the first injection moulding operation. During the second injection moulding operation, hot recycled material could flow through these channels to which the outer foil/label/barrier layer could engage. Depending on the placement of the channels with respect to the inner barrier layer, it could be that there is not enough barrier material between the recycled material and the interior surface of the container to prevent migration of contaminants from the recycled layer to the food contents. In this case, the channels could be arranged such that they are placed behind the inner barrier layer. In the embodiment shown in the figures, the side edge portions of the food grade material are shown to be quite wide and the side gap in the inner barrier foil to also be quite wide. However, in other embodiments, the gap in the inner barrier foil could be made smaller. It could also be imagined that the corner portions of the container have a slightly increased wall thickness, to ensure that there is room for both a layer of barrier material, a layer of food grade material, a layer of recycled material and possibly a layer of outer label.

The actual apparatus to manufacture the container according to the current invention could be provided in many different forms. However, one apparatus is schematically shown in figure 5. In this embodiment, two mould cores 50 are provided on a first side 52 of a rotating fixture 54 and two mould cores 56 are provided on a second side 58 of the rotating fixture 54. The mould cores are all identical in this embodiment. A first fixture 60 having two first mould cavities 62 is arranged on the first side of the rotating fixture and a second fixture 64 having two second mould cavities 66 is arranged on the second side of the rotating fixture 54. The first mould cavity 62 is arranged for forming the first injection moulded portion and the second mould cavity 66 is arranged for forming the second injection moulded portion. The first side 52 of the apparatus could be considered a first moulding station and the second side 58 of the apparatus could be considered a second moulding station.

During the process, the inner barrier foil is applied on the first side to the mould core 50 and the mould closed. The food grade material is then injected on the first side. The mould is opened and the fixture rotated 180 degrees. The injection moulded container moulded in the first step is not removed from the cores, but is just rotated with the core. A new inner barrier layer is added on the first side 52 and if desired, an outer foil can be added to the second mould cavity 66. The moulds are then closed again. Food grade material is injected on the first side 52 and recycled material is injected on the second side 58. This time when the mould is opened, the completed container is removed on the second side. The process is then repeated.

It should be noted that an apparatus similar to the one which was schematically shown in figure 5 could be provided with any number of cores/cavities. For example, an example of one core on either side of the fixture could be provided. Or an example of four cores arranged in a square pattern on either side of the fixture could be provided. Other combinations are also possible.

Another embodiment of an apparatus to manufacture the container according to the invention is shown in figure 6. In this case, the moulding station only acts on one side. In this case, the mould cavities 70,72 are all arranged on the same side of a rotating fixture 74. A corresponding fixture provided with matching cores (not shown) will be provided opposite to the fixture having the mould cavities 70,72. The mould cavities shown in dashed lines 70 are arranged as cavities which form the first injection moulded portion. The mould cavities shown in solid lines 72 are arranged as cavities which form the second injection moulded portion. The mould cores (not shown) are all identical.

In a first step, an inner barrier foil is applied to the cores associated with the first mould cavities 70. The mould is then closed and food grade material is injected into the first mould cavities. The mould is then opened and the fixture is rotated 180 degrees. New inner barrier foils are again applied to the cores associated with the first mould cavities 70 and if desired, outer foil layers are applied to the second mould cavities 72. The mould is closed and food grade material is injected into the first mould cavities and recycled material is injected into the second mould cavities 72. The mould is then opened and the finished container is removed from the second mould cavities 72. The fixture is then rotated again and the procedure repeated. The area shown with the dashed line 76 could be considered the first moulding station and the area shown outside the dashed line 78 could be considered the second moulding station.

In this embodiment, the fixture containing the mould cavities is shown to be rotated. However, in another embodiment, not shown, the fixture containing the cores could be rotated instead. Other forms of apparatus could also be provided as will be known to the person skilled in the art.

Figure 7 shows a partial exploded view of another embodiment 80 of a container according to the invention. In this case, the figure shows the inner barrier label 82 and the first injection moulded portion 84 made from the food grade material. The second injection moulded portion is not shown. In this embodiment, the first injection moulded portion 84 is injection moulded via four separate injection points 86 via four injection nozzles (not shown). In this case, there is no real bottom portion of the first injection moulded portion, just four side edge portions 88 and an upper rim portion 90. This can be used to reduce the flow lengths in the injection moulded portion as well as reducing the amount of food grade material needed.

It should be noted that the embodiments shown in the figures and described in this specification have been rectangular containers, however, a similar idea could also be applied to containers of other shapes. The scope of the claims should therefore cover containers of many different shapes, not just rectangular. In a round container for example, one could imagine an inner bottom barrier label and an inner wrap around side barrier label. The labels could be applied to a mould core. In a first injection moulding operation, food grade material is injected to seal the gap between the bottom and the side label, seal the gap/overlap at the side edges of the side label and then form the upper rim of the container. A second injection moulding procedure can then inject recycled material in the sidewall, outside the side barrier label and/or in the bottom, outside the bottom label barrier label.

It is to be noted that the figures and the above description have shown the example embodiments in a simple and schematic manner. Many of the specific mechanical details have not been shown since the person skilled in the art should be familiar with these details and they would just unnecessarily complicate this description. For example, the specific materials used and the specific injection moulding procedure have not been described in detail since it is maintained that the person skilled in the art would be able to find suitable materials and suitable processes to manufacture the container according to the current invention based on his or her common general knowledge and the teachings of this specification.