Biodegradable Multi-Layer Packaging Element, Such as a Foil or Wrap, for a Food Product, Packaging Unit with Such Packaging Element, and Method for Manufacturing Such Packaging Element

Abstract

The present invention relates to a biodegradable multi-layer packaging element, such as a foil or wrap, for a food product, a food packaging unit comprising such multi-layer and a method for manufacturing such biodegradable multi-layer, with the multi-layer comprising: —an inner cover layer comprising an amount of a biodegradable aliphatic polyester; —a first intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers; —a functional layer comprising a vinyl alcohol polymer; —a second intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers; and —an outer cover layer comprising an amount of a biodegradable aliphatic polyester.

Claims

1. A biodegradable multi-layer packaging element, such as a foil or wrap, for a food product, with the multi-layer comprising: an inner cover layer comprising an amount of a biodegradable aliphatic polyester; a first intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers; a functional layer comprising a vinyl alcohol polymer; a second intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers; and an outer cover layer comprising an amount of a biodegradable aliphatic polyester.

2. The biodegradable multi-layer packaging element according to claim 1, wherein the multi-layer is a co-extruded laminated multi-layer.

3. The biodegradable multi-layer packaging element according to claim 1, further comprising a paper layer.

4. The biodegradable multi-layer packaging element according to claim 3, further comprising a second paper layer.

5. The biodegradable multi-layer packaging element according to claim 3, wherein the paper layer comprises an opening for a window.

6. The biodegradable multi-layer packaging element according to claim 1, wherein the thickness of the individual layers is within the range of 1.5 to 50 μm.

7. The biodegradable packaging unit according to claim 1, wherein the functional layer is positioned asymmetrically in the multi-layer.

8. The biodegradable multi-layer packaging element according to claim 1, wherein the biodegradable aliphatic polyester comprises an amount of one or more of PBS, PHB, PHA, PCL, PLA, PGA, PBST, PBAT, PHBH and PHBV.

9. (canceled)

10. The biodegradable multi-layer packaging element according to claim 1, wherein the multi-layer comprises a colouring agent that is biodegradable.

11. (canceled)

12. The biodegradable multi-layer packaging element according to claim 1, wherein the biodegradable aliphatic polyester is bio-based.

13. A food packaging unit comprising a biodegradable multi-layer packaging element according to claim 1.

14. The food packaging unit according to claim 13, wherein the biodegradable multi-layer packaging element forms a foil to cover a compartment of the food packaging unit, wherein the biodegradable multi-layer is melted or fused with the compartment.

15. (canceled)

16. The food packaging unit according to claim 14, wherein the packaging unit comprises a layer of biodegradable aliphatic polyester on a contact surface to improve melting or fusing of the multi-layer thereon.

17. The food packaging unit according to claim 13, wherein the amount of biodegradable aliphatic polyester in the food packaging unit is in the range of 0.5 to 20 wt. %.

18. (canceled)

19. The food packaging unit according to claim 13, further comprising an amount of natural fibers and/or alternative fibers.

20. A method for manufacturing a biodegradable multi-layer packaging element, such as a foil or wrap, for a food product, the method comprising the step of providing a multi-layer comprising: an inner cover layer comprising an amount of a biodegradable aliphatic polyester; a first intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers; a functional layer comprising a vinyl alcohol polymer; a second intermediate layer of a biodegradable material for connecting and/or sealing adjacent layers; and an outer cover layer comprising an amount of a biodegradable aliphatic polyester.

21. The method according to claim 20, wherein providing the biodegradable multi-layer comprises the step of co-extruding the layers, and/or further comprising the step of providing a food packaging unit and providing the biodegradable multi-layer to the food packaging unit, and/or wherein the biodegradable multi-layer is melted or fused with at least a compartment of the food packaging unit, and/or further comprising the step of providing the biodegradable multi-layer as a biodegradable top seal film.

22.-24. (canceled)

25. The method according to claim 20, further comprising the step of performing sterilisation and pasteurisation of the packaging units.

26. The method according to claim 20, further comprising the step of biodegrading or decomposing the packaging unit.

27. (canceled)

28. The method according claim 20, further comprising the step of adding an amount of natural fibers and/or alternative fibers.

Description

[0117] Further advantages, features and details of the invention are elucidated on the basis of preferred embodiments thereof, wherein reference is made to the accompanying drawings, in which:

[0118] FIG. 1A shows a packaging unit for margarine having a packaging element according to the present invention as foil, more specifically acting as a cover;

[0119] FIG. 1B-E show different embodiments of a packaging element according to the invention

[0120] FIG. 2 shows a packaging element according to the invention as candy bar wrap;

[0121] FIG. 3 shows a container for coffee milk having a packaging element according to the invention as a foil;

[0122] FIG. 4 shows a food tray having a packaging element according to the invention as foil and having a paper layer with a window;

[0123] FIG. 5 shows a packaging element according to the invention as ice cream wrap;

[0124] FIG. 6 shows a pouch comprising a packaging element according to the invention;

[0125] FIG. 7 shows a container for yoghurt having a packaging element according to the invention as foil;

[0126] FIG. 8 shows a meat container having a packaging element according to the invention as foil; and

[0127] FIG. 9 shows experimental results with conventional packaging units and packaging units according to the present invention.

[0128] Container 2 (FIG. 1A) relates to a container for margarine. Container 2 has bottom part 4 and side walls 6 defining opening 8. Before use, opening 8 is covered with packaging element 10 comprising a biodegradable (laminated) multi-layer 10. In this embodiment there is provided a separate cover 12.

[0129] In the illustrated embodiment container 2 is provided with peelable packaging element 10. Edge 14 of packaging element 10 is peeled from edge 16 of container 2. In this embodiment packaging element 10 comprises a number of layers as transparent film and a paper layer. It will be understood that layers can also be provided as non-transparent, or alternatively as semi-transparent and/or partly transparent. Alternatively, container 2 can also be provided without cover 12.

[0130] Optionally, container 2 is manufactured from a moulded pulp material and comprises an additional film layer of biodegradable aliphatic polyester and/or may comprise an amount of biodegradable aliphatic polyester that is blended into the moulded pulp. This renders bottom part 4 and/or walls 6 water or liquid repellent and/or improves the heating step to melt or fuse (laminated) multi-layer 10 on or to edge 16. One of the further advantages of the use of biodegradable aliphatic polyester is the reduction or prevention of the liquid entering or migrating into the material during use. Another advantage is the constancy of size or dimensional stability.

[0131] Biodegradable packaging element 10 comprises a (laminated) multi-layer (FIG. 1B) comprising first cover layer 10a, first intermediate layer 10b, central functional layer 10c, second intermediate layer 10d, and second cover layer 10e. it will be understood that other layers can be added to multi-layer 10. It will be understood that (laminated) multi-layer 10 can be applied to container 2 and/or other packaging units that are illustrated or are not illustrated.

[0132] In an alternative embodiment (FIG. 1C) packaging element 10 comprises paper layer 10f. In a further alternative embodiment (FIG. 1D) packaging element 10 comprises second paper layer 10g. In this embodiment paper layers 10f, 10g provide a sandwich type configuration for multilayers 10a-e.

[0133] An alternative biodegradable packaging element 20 with a (laminated) multi-layer 20 (FIG. 1E) comprises first cover layer 20a, first intermediate layer 20b, first functional layer 20c, second intermediate layer 20d, central flexible layer 20e, third intermediate layer 20f, second functional layer 20g, fourth intermediate layer 20h, and second cover layer 20i. It will be understood that other layers can be added to multi-layer 20. It will be understood that (laminated) multi-layer 20 can be applied to container 2 and/or other packaging units that are illustrated or are not illustrated. It will also be understood that one or more paper layers 10f, 10g can be applied to multi-layer 20.

[0134] Wrap 102 (FIG. 2) comprises packaging element 110 for a candy bar 101 with a number of layers 10a-e, 20a-i and a paper layer 10f. Paper layer 10f is provided with text and illustrations.

[0135] Container 202 (FIG. 3) for holding coffee milk comprises bottom part 204 and side walls 206 defining opening 208. Before use, opening 208 is covered with packaging element 210 comprising a biodegradable (laminated) multi-layer 210, preferably according to one of the embodiments illustrated in FIGS. 1A-C.

[0136] In the illustrated embodiment container 202 is provided with peelable packaging element 210. Edge 214 of packaging element 210 is peeled from edge 216 of container 202. In this embodiment packaging element 210 comprises a number of layers 10a-e, 20a-i and a paper layer 10f.

[0137] Food tray 302 (FIG. 4) comprises bottom part 304 and side walls 306 defining compartment 307 configured for receiving and holding a product, and opening 308. Before use, opening 308 is covered with packaging element 310 comprising a biodegradable (laminated) multi-layer 310.

[0138] In the illustrated embodiment container 302 is provided with peelable packaging element 310. Edge 314 of packaging element 310 is peeled from edge 316 of container 302. In this embodiment packaging element 310 comprises a number of layers 10a-e, 20a-i as transparent film and a paper layer 10f. It will be understood that layers can also be provided as non-transparent, or alternatively as semi-transparent and/or partly transparent. In the illustrated embodiment paper layer 10f is provided with opening 318 enabling a consumer to inspect the contents of compartment 307.

[0139] Inner surface 320 of packaging unit 302 comprises PBS and/or PBAT and/or PBST and/or PLA material, optionally as film layer or alternatively blended and/or integrated with the fibres of the moulded pulp material. In the illustrated embodiment container 302 is manufactured from a moulded pulp or fluff pulp material, optionally comprising an amount of natural fibers and/or alternative fibers. This improves the possibilities for giving packaging unit 302 a natural paper feel and/or look. This may also be applied to other type of packaging units. For example, in instant or ready-to-eat meals, such that conventional sleeves can be omitted from the packaging units. This enables a more cost-efficient packaging unit with a possible weight reduction.

[0140] Packaging unit 302 has numerous applications, including but not limited to, airplane meals. Such meals are provided to the airplane after (dry) sterilisation and pasteurisation. In combination with the (O.sub.2)-barrier properties of the (laminated) multi-layer (and top seal film) the shelf-life of the food product is significantly improved. In addition, the O.sub.2-barrier prevents or at least reduces oxidation processes in the food and thereby contributes to the maintenance of food taste.

[0141] Wrap 402 (FIG. 5) comprises packaging element 410 for a candy bar 401 with a number of layers 10a-e, 20a-i and a paper layer 10f. Paper layer 10f is provided with text and illustrations.

[0142] Pouch 502 (FIG. 6) for holding solid and/or liquid products such as soup comprises bottom part 504 and side wall 506 with opening 508. In the illustrated embodiment bottom part 504 and side wall 506 comprises packaging element 510. In this embodiment packaging element 510 comprises a number of layers 10a-e, 20a-i and a paper layer 10f.

[0143] Container 602 (FIG. 7) for holding a food product such as yoghurt comprises bottom part 604 and side walls 606 defining opening 608. Before use, opening 608 is covered with packaging element 610 comprising a biodegradable (laminated) multi-layer 610.

[0144] In the illustrated embodiment container 602 is provided with peelable packaging element 610. Edge 614 of packaging element 610 is peeled from edge 616 of container 602. In this embodiment packaging element 610 comprises a number of layers as transparent film 10a-e, 20a-i and paper layer 10f. It will be understood that layers can also be provided as non-transparent, or alternatively as semi-transparent and/or partly transparent.

[0145] Packaging unit 802 (FIG. 8) for holding meat 801 comprises bottom part 804 and side walls 806 defining an opening. Bottom part 804 comprises a number of protrusions or spikes 803. In the illustrated embodiment meat 801 lies on foil 809 and is covered by packaging element 810 having a number of layers 10a-e, 20a-i that are preferably transparent. Lower foil 809 also comprises a number of layers 10a-e, 20a-i and/or comprises an absorbent material.

[0146] It will be understood that other types of food packaging units and/or packaging elements can also be envisaged in accordance with the present invention. Other examples of food packaging products may relate to cup carriers, cups, plates and other table ware etc.

[0147] When manufacturing a packaging element 10, 110, 210, 310, 410, 510 and/or food packaging unit 2, 102, 202, 302, 402, 502 preferably a moulded pulp material is prepared. Optionally, an amount of biodegradable aliphatic polyester, such as PBS and/or PBAT and/or PBST and/or PHBH, is blended or mixed into the moulded pulp material and/or an amount of biodegradable aliphatic polyester, such as PBS and/or PBAT and/or PBST and/or PHBH is included in a separate layer that is provided in or on the packaging unit 2, 102, 202, 302, 402, 502. Such separate layer may improve the contact with (laminated) multi-layer 10, 110, 210, 310, 410, 510, optionally comprising a vinyl alcohol polymer, such as HAVOH and/or BVOH. Preferably, (laminated) multi-layer is co-extruded with the moulded pulp material and deep-drawn. In addition, or as an alternative, the raw unit is moulded. Optionally, the raw unit is dried in the mould applying an in-mould drying process. In such alternative embodiment (laminated) multi-layer 10, 110, 210, 310, 410, 510 is provided in the mould and a heating step is performed. Optionally, an additional layer of biodegradable aliphatic polyester is provided to improve the contact between the packaging unit and the (laminated) multi-layer. Finally the product is released from the mould.

[0148] Several post-drawing or post-moulding operations may optionally be performed in relation to unit 2, 102, 202, 302, 402, 502 optionally including, but not limited to, labelling including in-mould labelling, marking including printing and digital printing, testing. In several of the preferred embodiments, the compostable (laminated) multi-layer 10, 110, 210, 310, 410, 510 is at least arranged on the food contact area of the product containing part of the packaging unit. In preferred embodiments this film is capable of being used in a microwave or oven as a so-called ovenable film. Preferably, layer 10, 110, 210, 310, 410, 510 is capable of withstanding temperatures up to 170° C., 190° C., or even higher. The biodegradable aliphatic polyester preferably comprises an amount of PBS and/or PBAT and/or PBST and/or MFC and/or biodegradable aliphatic polyester that may comprise an amount of one or more of PHB, PHA, PCL, PLA, PGA, PBAT, PBST, PHBH and PHBV. Especially a combination of a compostable packaging unit involving extrusion and/or in-mould drying further improves the sustainability as compared to conventional packaging units. The (digital) printable properties enable printing of packaging and/or food characteristics/information. This may obviate the use of separate sleeves, for example. In addition, it enables the application of prints, for example a fish & chips (newspaper) print on the packaging unit.

[0149] Experiments have been performed with one or more of the illustrated food packaging elements and/or units that were provided with (laminated) multi-layer 10, 110, 210, 310, 410, 510. These experiments involved comparing the “in-use” characteristics of the food packaging elements and/or units as compared to conventional packaging elements and/or units, and also the compostable characteristics. An amount of a biodegradable aliphatic polyester was added to the moulded pulp material and a refining step was performed. Measurements were done at a temperature of about 23° C. and a relative humidity of about 50%. Measurements involved a compression test. This showed a significant improvement in compression value. For example, a packaging unit with 7.5% PLA and a refining step showed a compression value of 450 to 500 N, while for a similar conventional product under the same conditions this value is about 180 N. Even a sub-optimal conditions of RH about 90% the compression value for the packaging unit according to the invention was about 250 to 270 N, thereby still outperforming the conventional product at its optimal conditions.

[0150] In a further test the multi-layer was applied to the food packaging element and/or unit and for 24 hours exposed to 23° C. and a relative humidity of about 50%. No oxygen penetration, referred to as the oxygen transfer rate (OTR), was detected. In fact, oxygen penetration was below 0.08 ml/m.sup.2 day.

[0151] Further experiments in relation to the OTR were performed on several samples at a temperature of about 23° C. and a relative humidity of about 50%. Different multi-layers were tested. Samples in accordance with multi-layer 10 having one functional layer were tested having PBAT-PLA or PBAT cover layers and a GPolymer functional layer (thickness of 4 or 6 μm) and a total thickness of about 100 μm or about 120 μm, respectively. Also, samples in accordance with multi-layer 20 having two functional layers were testes having PBAT-PLA cover layers and two GPolymer functional layers (thickness of 2×2 or 2×3 or 2×4 μm) and a total thickness of about 80 μm, about 100 μm, about 120 μm, or about 150 μm, respectively, and a (central) flexibility layer of a blend of biopolymers, such as PBS, PBAT and/or PBST. Also, these samples showed an OTR below 0.08 ml/m.sup.2 day, and even below 0.05 ml/m.sup.2 day, which was the lowest test limit in this experiment. These experiments confirmed an OTR below 1 ml/m.sup.2 d, and even below 0.1 ml/m.sup.2 d, is achieved. Optionally, the inner and outer cover layers are provided with different thicknesses.

[0152] Further tests related to the water vapor transmission rate (WVTR). Several biofilms with multi-layer 10, 20 were tested. In Table 1 some experimental results are included. Tests were performed at a temperature of about 23° C. and a relative humidity of about 50%. In the table results are shown for two samples of the same composition.

TABLE-US-00001 TABLE 1 WVTR measurements measurement Biofilm measurement type PBS cover and below 3000 mg/m.sup.2 d Aquatran GPolymer (thick) PBS cover and below 3000 mg/m.sup.2 d Aquatran GPolymer (thick) PBS cover and 3000-3500 mg/m.sup.2 d Aquatran GPolymer (thin) PBS cover and 3000-3500 mg/m.sup.2 d Aquatran GPolymer (thin) PBAT-PLA cover 2000-2500 mg/m.sup.2 d Aquatran and GPolymer PBAT-PLA cover 2000-2500 mg/m.sup.2 d Aquatran and GPolymer Cover only: Blend around 20 g/m.sup.2 d Permatran PBAT and PLA (indicative value)* Cover only Blend around 20 g/m.sup.2 d Permatran PBAT and PLA (indicative value)*

[0153] Results show that water vapor transmission can be reduced significantly as compared to conventional materials that show water vapor transmission rates of up to 200 g/m.sup.2 d. Also, at higher temperatures and pressures the transmission rate remains functional. Due to the fact that the functional layer of the biofilm is protected on both sides by a thin intermediate (tie) layer of PBAT (biopolyester) these layers avoid that the functional layer of GPolymer gets affected by water. This supports the good WVTR barrier properties of the entire film composition. Furthermore, the low water vapor transmission rate that is achieved also reduces the loss of aroma due to a high WVTR.

[0154] Other tests were performed to show the dual ovenable (oven and microwave) performance of the packaging element and/or unit according to the invention. In the experiments the (laminated) product was heated to a temperature of about 190° C. for about 30 minutes. Results show that the film layer remains intact and does not melt. No leakage was detected. Furthermore, the strength and stability of the packaging element and/or unit were not significantly affected. As a further effect, the packaging unit was more stable in view of twisting when removing the packaging unit from the oven as is often the case with conventional packaging units. Furthermore, the packaging element and/or unit of the invention showed a limited temperature increase to about 50 to 70° C., while the conventional units reached a temperature of about 90 to 100° C. under similar conditions. Other experiments with a (food) tray shows an even improved heat resistance when heating the tray to a temperature of 180 to 200° C., and in addition shows (an improved) oil, acid and moisture resistance/repellence.

[0155] Other test were performed to show the performance of the packaging unit according to the invention by heating the packaging unit in an oven and/or microwave. In the experiments the (laminated) product, comprising a (laminated) layer with a total thickness of about 40 μm, was heated to a temperature of about 180° C. for about 35 minutes. Results show that the film layer remains intact and does not melt. No leakage was detected. Furthermore, the strength and stability of the packaging unit were not significantly affected. As a further effect, the packaging unit was more stable in view of twisting when removing the packaging unit from the oven as is often the case with conventional packaging units. Leaking of the film layer was tested by using food simulantia such as 95% ethanol, modified polyphenylene oxide (MPPO), 2,2,4-trimethylpentane, and the like. Thus, this test showed a safe use of the laminate product as packaging, for example food packaging.

[0156] Additional tests compared the temperature on the outside of the packaging element and/or unit after cooking (“cool to touch”) with different types of meals by heating in both the microwave and oven between a conventional packaging unit from CPET (Crystalline Polyethylene Terephthalate) and a packaging unit that is about 100% biodegradable and made from moulded fibre. The cooking instructions for the ready meals were: [0157] Microwave: 5 minutes at 700 Watt; [0158] Oven: 30 minutes at 180° C. (air heated).

[0159] For the measurements, an IR (infrared) thermometer was used to observe the temperature on the outside of different parts of each tray/packaging unit.

[0160] Temperature of the food trays was measured regularly, starting directly after being taken out of the oven/microwave. Results for temperatures at the upper part of the trays are shown in FIG. 9 and are representative for the entire packaging units.

[0161] Results clearly show a substantial temperature difference in the range of 10-15° C. showing that the packaging unit according to the invention is cooler when being touched by a user. Food temperatures are similar in both packaging units during the entire time period. During the experiments it was observed that the CPET trays became “wobbly”/unstable after heating. In addition, the biodegradable packaging unit has a weight that is about 10% lower as compared to the CPET tray, while outperforming this CPET tray.

[0162] In still further tests other characteristics were examined. It was shown that wipeability of the packaging unit could be improved. Further improvements where shown by addition of further additives.

[0163] Also, shelf-life tests were performed. In these tests a packaging unit with a packaging element involving a (laminated) multi-layer as a top seal film according to the invention is compared to a conventional packaging unit for fresh meals. Tests revealed a significant shelf-life increase from about 8 days to 12 days.

[0164] The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged.