Biodegradable and Compostable Food Packaging Unit from a Moulded Pulp Material with a Cellulose-Base Laminate Layer, and Method for Manufacturing Such Food Packaging Unit

Abstract

The present invention relates to a biodegradable food packaging unit (2) from a moulded pulp material and a method for manufacturing such biodegradable packaging unit. The packaging according to the invention comprises a food receiving or carrying compartment having a food contact surface, wherein the moulded pulp material comprises an amount of a biodegradable aliphatic polyester; wherein the food contact surface comprises a cellulose-based laminate layer (10); and wherein the food packaging unit is a compostable food packaging unit. In a preferred embodiment the amount of biodegradable aliphatic polyester is in the range of 0.5-20 wt. %, more preferably in the range of 1-15 wt. %.

Claims

1. Food packaging unit from a moulded pulp material, the packaging unit comprising a food receiving or carrying compartment having a food contact surface, wherein the moulded pulp material comprises an amount of a biodegradable aliphatic polyester; wherein the food contact surface comprises a cellulose-based laminate layer; and wherein the food packaging unit is a compostable food packaging unit.

2. Food packaging unit according to claim 1, wherein the cellulose-based laminate layer is melted or fused with the biodegradable aliphatic polyester.

3. Food packaging unit according to claim 1, wherein the amount of biodegradable aliphatic polyester is in the range of 0.5-20 wt. %.

4. (canceled)

5. Food packaging unit according to claim 1, wherein the biodegradable aliphatic polyester comprises an amount of one or more of PBS, PHB, PHA, PCL, PLA, PGA, PHBH and PHBV.

6. Food packaging unit according to claim 1, wherein the packaging unit comprises a layer of biodegradable aliphatic polyester on the food contact, surface to improve melting or fusing of the cellulose-based laminate layer with the packaging unit.

7. Food packaging unit according to claim 1, wherein the packaging unit comprises a circumferential edge comprising a connecting surface that is substantially free of the laminate layer to enable providing a transparent layer as closure of the packaging unit.

8. Food packaging unit according to claim 1, wherein the cellulose-based laminate layer comprises a colouring agent.

9. Food packaging unit according to claim 8, wherein the colouring agent is biodegradable.

10. Food packaging unit according to claim 1, wherein the cellulose-based laminate layer comprises a print.

11. Food packaging unit according to claim 10, wherein the print is provided on the moulded pulp material side of the cellulose-based laminate layer in a mirror image such that the print can be seen from the food side of the cellulose-based laminate layer.

12. Food packaging unit according to claim 1, wherein the unit is biodegradable at a temperature in the range of 5 to 60 C.

13. Food packaging unit according to claim 1, wherein the biodegradable aliphatic polyester is bio based.

14. Food packaging unit according to claim 1, further comprising an amount of natural and/or alternative fibers.

15. Method for manufacturing a food packaging unit from a moulded pulp material, the method comprising the steps of: preparing moulded pulp material; adding an amount of biodegradable aliphatic polyester; moulding the food packaging unit; providing a cellulose-based laminate layer; and releasing the food packaging unit from the mould.

16. Method according to claim 15 further comprising the step of subjecting the packaging unit to a heating step heating the packaging unit to a temperature about the melting temperature of the biodegradable aliphatic polyester to crosslink/interact with the cellulose fibers of the laminate layer to increase strength and improve barrier properties, wherein the cellulose-based laminate layer is provided to the packaging unit in an in-mould processing step, wherein moulding the food packaging unit comprises connecting biodegradable aliphatic polyester to cellulose fibres of the moulded pulp material, and wherein the heating step heats the temperature of the packaging unit to a heating temperature in the range of 145-195 C.

17. (canceled)

18. (canceled)

19. Method according to claim 15, wherein adding an amount of biodegradable aliphatic polyester in the range of 0.5-20 wt. %.

20. (canceled)

21. Method according to claim 15, further comprising the step of biodegrading the packaging unit, wherein biodegrading comprises decomposing the food packaging unit, and wherein the decomposing is performed at a temperature in the range of 5 to 40 C.

22. (canceled)

23. (canceled)

24. Method according to claim 15, further comprising the step of in-mould drying the packaging unit.

25. Method according to claim 15, further comprising the step of adding an amount of natural fibers.

26. Food packaging unit from a moulded pulp material, the packaging unit comprising a food receiving or carrying compartment having a food contact surface, wherein the moulded pulp material comprises an amount of a biodegradable aliphatic polyester; wherein the food contact surface comprises a cellulose-based laminate layer; and wherein the food packaging unit is a compostable food packaging unit, wherein the cellulose-based laminate layer is melted or fused with the biodegradable aliphatic polyester, wherein the amount of biodegradable aliphatic polyester is in the range of 0.5-20 wt. %.

Description

[0082] 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:

[0083] FIGS. 1A and 1B show a packaging unit configured for receiving a food product according to the present invention

[0084] FIGS. 1C and 1D show an alternative packaging unit according to the present invention;

[0085] FIG. 2 shows a plate as food receiving product according to the invention;

[0086] FIGS. 3A and 3B shows a packaging unit according to the invention comprising PBS and/or another biodegradable aliphatic polyester;

[0087] FIG. 4 shows an example of an alternative food packaging product according to the present invention;

[0088] FIG. 5 shows further packaging units for a bottle divider according to the present invention; and

[0089] FIGS. 6A and 6B show further packaging units according to the invention;

[0090] FIGS. 7A and 7B show a packaging unit for eggs according to the invention; and

[0091] FIG. 8 shows experimental results with conventional packaging units and packaging units according to the present invention.

[0092] Packaging unit 2 (FIG. 1A) relates to a food receiving container having bottom part 4 and side walls 6 defining opening 8. On the inside of container 2 there is provided cellulose-based laminate layer 10. In the illustrated embodiment layer 10 comprises print 12. Preferably, in the illustrated embodiment the print is provided on the back side of laminate layer 10. Laminate layer 10 (FIG. 1B) comprises a food oriented side 14 and a packaging side 16. In the illustrated embodiment parts 18 can be removed or cut from sheet or layer 10 to dimension laminate layer 10 according to the specifications and enable providing layer 10 into the inside of container 2. This enables positioning laminate layer 10 correctly relative to corners 20. In this illustrated embodiment print 12 is provided in a mirror image on package side 16 of laminate layer 10 to render the render print 12 visible for a user or consumer.

[0093] Packaging unit 22 (FIG. 1C) provides a further embodiment of a food receiving container having bottom part 24 and side walls 26 defining opening 28. Packaging unit 22 has length L, width W and height H. On the inside of container 22 there is provided laminate layer 30, optionally comprising a print. In the illustrated embodiment laminate layer 30 is provided on the inside of packaging unit 22 and extends from bottom part 24 up to contour or edge 32. Contour or edge 32 is provided a small distance from the upper side of edge 34. This distance is preferably in the range of 1 to 12 mm. Edge 34 (FIG. 1D) is provided with width W1 that defines contact surface 36 for connecting to a liner or seal. In the illustrated embodiment this liner or seal is connected directly to the moulded pulp material, optionally with an adhesive, in stead of being connected to laminate layer 30. Width W1 is in the illustrated embodiment in the range of 1 to 15 mm, preferably in the range of 2 to 5 mm.

[0094] Packaging unit 22 (FIG. 1C) comprises first denesting elements 38 and second denesting elements 40. In the illustrated embodiment denesting elements 38, 40 enable denesting of a stack of packaging units 22. Denesting elements 38, 40 are designed asymmetrically. It will be understood that alternative denesting elements can also be envisaged in accordance with the present invention as alternatives or in combination. These alternative denesting elements can be designed asymmetrically or symmetrically. Asymmetrical denesting elements enable denesting with packaging units 22 in one orientation and disable or at least render denesting more difficult in another orientation. Denesting elements 38, 40 have as an additional advantage that these elements do not significantly change the size of contact surface 36 and/or the internal volume of packaging unit 22. In the illustrated embodiment, denesting elements 38, 40 are provided at or adjacent edge 34. This prevents the provision of marks, edges, protrusions, nocks and the like on or close to bottom part 24. Such irregularities on or close to bottom part 24 hinders cleaning or emptying packaging unit 22.

[0095] In another embodiment plate 50 (FIG. 2) is on the food receiving side provided with cellulose-based laminate layer 52. In the illustrated embodiment bottom or back side 54 of plate 50 is not provided with such laminate layer.

[0096] Packaging unit 102 (FIGS. 3A and B) carries or holds eggs and comprises cover part 104 and bottom part 106. In the illustrated embodiment packaging unit 102 comprises laminate layer 101. Bottom part 106 is provided with back surface 108, sides 110 and front surface 112, and bottom surface 114. Cover part 104 is provided with back surface 116, side surfaces 118, front surface 120 and top surface 122. In the illustrated embodiment transition 124 is provided between top surface 122 and back and front surfaces 116, 120.

[0097] In the illustrated embodiment, top surface 122 of cover part 104 is provided with groove 126 comprising a number of openings 128. Openings 128 are defined by two adjacent arch-shaped edges 130, 132 having a larger thickness as compared to the average thickness of cover part 104. Side surfaces 118 of cover part 104 are provided with denest nocks or denest elements 134. In the illustrated embodiment, bottom part 106 is provided with similar elements 136 mirroring denest elements 134. Hinge 138 connects back surface 116 of cover part 104 with back surface 108 of bottom part 106. Lock 140 comprises nose-shaped lock element 142 that is connected to flap 144 of bottom part 106. Cover part 104 is provided with openings 146 that capture lock elements 142 therewith defining lock 140.

[0098] In the illustrated embodiment, bottom part 106 is provided with a number of product receiving compartments 148, cones 150 and separating walls 152. Cone 150 extends from the bottom of bottom part 106 in an upward direction. Cover part 104 comprises cone support 154. Inner surface 158 of packaging unit 102 comprises PBS and/or PLA material, optionally as film layer or alternatively blended and/or integrated with the fibres of the moulded pulp material.

[0099] In the illustrated embodiment, packaging unit 102 comprises twelve product receiving compartments 48 that are provided in two rows of six compartments 148. Individual compartments 48 are separated from each other by walls 152 and cones 150. It will be understood that other configurations can also be envisaged in accordance to the invention.

[0100] Packaging unit 102 may also be configured to receive other products, such as tomatoes, kiwis.

[0101] It will be understood that other types of food packaging units can also be envisaged in accordance with the present invention.

[0102] Packaging unit 202 (FIG. 4) comprises laminate layer 201 that is provided on bottom part 204 and cover part 206. Unit 202 is provided with biodegradable aliphatic polyester, such as PBS and/or PLA, and is capable of holding an amount of ice cream. Cover part 206 comprises top seal 208 of a (paper) label whereon layer or film 210 of biodegradable aliphatic polyester(s) is provided. Optionally, fibers 212 are included in the cover part 206. This improves the possibilities for giving the unit 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.

[0103] As a further example, bottle divider 302 (FIG. 5) is illustrated with cellulose-based laminate layer 301. Also, bottle divider 102 may comprise an additional film layer of PBS (and/or appropriate alternative biodegradable aliphatic polyester) and/or may comprise an amount of PBS that is blended into the moulded pulp.

[0104] A further example in accordance with the present invention is cover 402, for example for an ice cup (FIG. 6A) that is provided with laminate layer 401. Another example of a packaging unit according to the invention is sip lid 502 (FIG. 6B) that is provided with laminate layer 501. Cover 402 and sip lid 502 comprise 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 cover 402 and sip lid 502 water or liquid repellent and/or improves the heating step to melt or fuse cellulose-based layer 401, 501 on or to cover 402 and/or sip lid 502. 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 sip lid material during use. Another advantage is the constancy of size or dimensional stability. In this specific case this prevents sip lid 502 loosening from a cup or beaker for hot beverages such as coffee, tea or soup, or cold beverages such as carbonated drinks, and cup 402 from loosing from an ice cup, for example. It will be understood that such lids 502 can also be applied to other food containers. For example, lids 502 can be applied to containers for milkshakes, for example. Further details and examples of lids 502 are disclosed in WO 2010/064899, including embodiments with specific flanges and notches.

[0105] Sip lid 502 is preferably coated with a biodegradable aliphatic polyester liner, such as a PBS liner in addition to cellulose-based laminate layer 501 to improve the melting properties. As mentioned, sip lids 502 can be used for cups and milkshakes. Also, sip lids can be applied to so-called ready meal trays (for example for pizza, wraps, fish, meat, lobster, pasta, . . . ) and act as a (digital) printable and barrier seal, for example.

[0106] It will be understood that other designs for packaging units in accordance with the invention can be envisaged. For example, containers 602, 702 (FIGS. 7A and B) illustrate different designs for egg cartons capable of holding eggs P and comprise cellulose-based laminate layer 601, 701.

[0107] Other examples of food packaging products may relate to cup carriers, cups, plates and other table ware etc.

[0108] When manufacturing a food packaging unit 2, 50, 102, 202, 302, 402, 502, 602 a moulded pulp material is prepared. Optionally, an amount of biodegradable aliphatic polyester, such as PBS, is blended or mixed into the moulded pulp material and/or an amount of PBS is included in a separate layer that is provided in or on unit 2, 50, 102, 202, 302, 402, 502, 602. Such separate layer may improve the contact with cellulose-based laminate layer 10, 52, 101, 201, 301, 401, 501, 601. Preferably, the raw unit is moulded. Optionally, the raw unit is dried in the mould applying an in-mould drying process. In a presently preferred embodiment cellulose-based laminate layer 10, 52, 101, 201, 301, 401, 501, 601 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 laminate layer. Finally the product is released from the mould. Several post-moulding operations may optionally be performed in relation to unit 2, 50, 102, 202, 302, 402, 502, 602 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 laminate layer 10, 52, 101, 201, 301, 401, 501, 601 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, 52, 101, 201, 301, 401, 501, 601 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 MFC and/or biodegradable aliphatic polyester that may comprise an amount of one or more of PHS, PHA, PCL, PLA, PGA, PHBH and PHBV. Especially a combination of a compostable packaging unit involving 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.

[0109] Experiments have been performed with one or more of the illustrated food packaging units that were provided with cellulose-based layer 10, 52, 101, 201, 301, 401, 501, 601. These experiments involved comparing the in-use characteristics of the food packaging units as compared to conventional packaging 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 450-500 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 250-270 N, thereby still outperforming the conventional product at its optimal conditions.

[0110] Other tests were performed to show the dual ovenable (oven and microwave) performance of the packaging 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. 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. Furthermore, the packaging unit of the invention showed a limited temperature increase to about 50-70 C., while the conventional units reached a temperature of about 90-100 C. under similar conditions. Other experiments with a (food) tray shows an even improved heat resistance when heating the tray to a temperature of 180-200 C., and in addition shows (an improved) oil, acid and moisture resistance/repellence.

[0111] Additional tests compared the temperature on the outside of the product packaging 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 100% biodegradable and made from moulded fibre. The cooking instructions for the ready meals were: [0112] Microwave: 5 minutes at 700 Watt; [0113] Oven: 30 minutes at 180 C. (air heated).

[0114] For the measurements, an IR (infrared) thermometer was used to observe the temperature on the outside of different parts of each tray/packaging unit.

[0115] 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. 8 and are representative for the entire packaging units.

[0116] 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.

[0117] 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.

[0118] 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.