Packaging sheet for packaging of cheese, and associated packaging and manufacturing methods

Abstract

Disclosed is a packaging sheet for packaging of cheese, in particular white moulded soft cheese. The packaging sheet comprises: an inner surface and an outer surface of the packaging sheet, said inner surface being configured for facing the cheese in a packaged use position of the packaging sheet; a paper layer with a first surface and a second surface; a coloured layer provided on a first surface of the paper layer, an outer surface of the coloured layer establishing said outer surface of the packaging sheet; and a polymer layer with a water vapour transmission rate of at least 300 g/m2/24 hours at 38° C. and 90% atmospheric humidity. The polymer layer being coated on the second surface of the paper layer with a first surface of the polymer layer facing the paper layer and a second surface of the polymer layer establishing said inner surface of the packaging sheet.

Claims

1. A packaging sheet for packaging of cheese, comprising an inner surface and an outer surface of the packaging sheet, said inner surface being configured for facing the cheese in a packaged use position of the packaging sheet, a paper layer with a first surface and a second surface, the paper layer having a thickness in the range of 25 to 50 g/m.sup.2, a coloured layer provided at or on the first surface of the paper layer, an outer surface of the coloured layer establishing said outer surface of the packaging sheet, and a polymer layer with a water vapour transmission rate in a range of at least 300 g/m.sup.2/24 hours to 1200 g/m.sup.2/24 hours at 38° C. and 90% atmospheric humidity, the polymer layer being positioned at the second surface of the paper layer with a first surface of the polymer layer facing the paper layer and a second surface of the polymer layer establishing said inner surface of the packaging sheet, wherein the polymer layer comprises polyester or polyethylene terephthalate (PET), wherein the polymer layer is nonporous, wherein the packaging sheet has an oxygen transmission rate of at least 2000 cm.sup.3/m.sup.2/24 hours/bar.

2. The packaging sheet according to claim 1, wherein an adhesive layer is provided between the paper layer and the polymer layer, the adhesive layer and the polymer layer being co-extruded on the paper layer.

3. The packaging sheet according to claim 2, wherein the adhesive layer comprises ethylene-acrylic ester-maleic anhydride (EVA) terpolymer.

4. The packaging sheet according to claim 2, wherein the coextruded adhesive and polymer layers are provided in the packaging sheet with an accumulated thickness corresponding to a weight of 5 to 9 g/m.sup.2.

5. The packaging sheet according to claim 2, wherein the adhesive layer consists of ethylene acrylic ester maleic anhydride (EMA) terpolymer.

6. The packaging sheet according to claim 1, wherein the paper layer extends over a majority of the first surface of the polymer layer.

7. The packaging sheet according to claim 6, wherein the paper layer extends over an entirety of the first surface of the polymer layer.

8. A packaging sheet for packaging of cheese, comprising an inner surface and an outer surface of the packaging sheet, said inner surface being configured for facing the cheese in a packaged use position of the packaging sheet, a paper layer with a first surface and a second surface, the paper layer having a thickness in the range of 25 to 50 g/m.sup.2, a coloured layer provided at or on the first surface of the paper layer, an outer surface of the coloured layer establishing said outer surface of the packaging sheet, and a polymer layer with a water vapour transmission rate in a range of 300 g/m.sup.2/24 hours to 1200 g/m.sup.2/24 hours at 38° C. and 90% atmospheric humidity, the polymer layer being positioned at the second surface of the paper layer with a first surface of the polymer layer facing the paper layer and a second surface of the polymer layer establishing said inner surface of the packaging sheet, wherein the polymer layer comprises an ethylene-methyl acrylate copolymer lacquer of a type which is obtained by emulsifying ethylene-methyl acrylate copolymer in water, wherein the packaging sheet has an oxygen transmission rate of at least 2000 cm.sup.3/m.sup.2/24 hours/bar, wherein the polymer layer is nonporous.

9. The packaging sheet according to claim 8, wherein the polymer layer is provided with a thickness corresponding to 2 to 8 g/m.sup.2.

10. The packaging sheet according to claim 8, wherein the polymer layer is provided with a thickness corresponding to 2 to 6 g/m.sup.2.

11. The packaging sheet according to claim 8, wherein the paper layer extends over a majority of the first surface of the polymer layer.

12. The packaging sheet according to claim 11, wherein the paper layer extends over an entirety of the first surface of the polymer layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above and/or additional objects, features and advantages of the present invention will be further outlined by the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the appended drawings, wherein:

(2) FIG. 1 shows a schematic view of a packaging sheet according to an embodiment of the present invention.

(3) FIG. 2 shows a schematic view of a packaging sheet according to another embodiment of the present invention.

(4) FIG. 3 shows a schematic view of a packaging sheet according to another embodiment of the present invention.

(5) FIG. 4 schematically shows a piece of cheese wrapped in a packaging sheet according to an embodiment of the present invention.

(6) FIG. 5 is a cross sectional view of the cheese package of FIG. 4 taken along the line IV-IV of FIG. 4.

(7) FIG. 6 shows a flowchart of a method for manufacturing a packaging sheet according to an embodiment of the present invention.

DETAILED DESCRIPTION

(8) In the following description, reference is made to the accompanying figures, which show by way of illustration how the invention may be practiced. Note that for illustrative purposes the dimensions of especially thicknesses of the different sheets shown are exaggerated.

(9) FIGS. 1 and 2 show a packaging sheet 1 for packaging of one or more pieces of cheese 15, in particular white moulded soft cheese, as shown in FIG. 4. The packaging sheet 1 comprises an inner surface 2 and an outer surface 3. The inner surface 2 faces the cheese 15 in the packaged use position of the packaging sheet 1 shown in FIG. 4. The packaging sheet 1 comprises a paper layer 4. The paper layer 4 has a first surface 5 and a second surface 6. The packaging sheet 1 comprises a coloured layer 7. The coloured layer 7 is provided on the first surface 5 of the paper layer. An outer surface 9 of the coloured layer 7 establishes the outer surface 3 of the packaging sheet 1. The packaging sheet 1 further comprises a polymer layer 8. The polymer layer 8 has a first surface 10 and a second surface 11. The polymer layer 8 has a water vapour transmission rate of at least 300 g/m.sup.2/24 hours at 38° C. and 90% atmospheric humidity. The polymer layer 8 is coated on the second surface 6 of the paper layer 4. Thereby the first surface 10 of the polymer layer 8 faces the paper layer 4. And the second surface 11 establishes the inner surface 2 of the packaging sheet 1. The packaging sheet 1 further has a water vapour transmission rate lower than or equal to 1000 g/m.sup.2/24 hours at 38° C. and 90% atmospheric humidity. The packaging sheet 1 has an oxygen transmission rate higher than or equal to 2000 cm.sup.3/m.sup.2/24 hours/bar. The paper layer 4 extends over substantially an entirety of the first surface 10 of the polymer layer 8.

(10) FIG. 1 shows a polymer layer 8, which is a polyester layer 12, specifically a PET layer.

(11) FIG. 2 shows a polymer layer 8, which is an ethylene-methyl acrylate copolymer lacquer 13. The lacquer 13 may be of a type which is obtained by emulsifying ethylene-methyl acrylate copolymer in water. The ethylene-methyl acrylate copolymer lacquer 13 is provided at 2 to 8 g/m.sup.2, preferably 2 to 6 g/m.sup.2, more preferred 2 to 4 g/m.sup.2.

(12) FIG. 3 shows a packaging sheet 1 as described with reference to to FIG. 1 where an adhesive layer 14 is furthermore provided between the paper layer 4 and the polyester layer 12 for adhesion of the layers together. The adhesive layer 14 is preferably a layer of ethylene-acrylic ester-maleic anhydride (EMA) terpolymer. The adhesive layer 14 and the polyester layer 12 are co-extruded on a second surface 6 of the paper layer 4. The coextruded adhesive layer 14 and polyester layer 12 are provided at 5 to 9 g/m.sup.2, preferably 6 to 8 g/m.sup.2, more preferred 6.5 to 7.5 g/m.sup.2.

(13) FIGS. 4 and 5 show different view of a packaged piece of white moulded soft cheese 15 forming a cheese package 20. The cheese package 20 may be arrived at by firstly cutting out or otherwise providing a piece of the cheese 15 of suitable size and shape. A suitable size may be 2-4 by 2-20 by 2-20 cm. A packaging sheet 1, which may be according to any one of the above described embodiments, is cut out from a larger piece of packaging sheet (not shown), specifically a long length of wrapping of packaging sheet, which is conventionally rolled off of a large roll and led into a cutting machine that cuts out suitable pieces of the larger packaging sheet into sheet sizes and shapes suitable for being wrapped around the cheese 15. Such a roll may have a width of 1-2 m and a rolled up sheet length of several hundred meters. The cut out packaging sheet 1 may be cut into a rectangular or square of 5-30 by 5-30 cm. Next, the cheese 15 is wrapped in the cut out packaging sheet 1 as will be described in the following.

(14) First the plane, i.e. un-folded and un-bent, packaging sheet 1 is positioned on a plane packaging surface, and the cheese 15 is positioned substantially centrally on with a lower surface abutting the packaging sheet 1. Then the peripheral edges of the packaging sheet 1 are lifted upwards from the plane surface and are led towards each other above the cheese 15 until the cheese 15 is wrapped within, enclosed by the packaging sheet 1. In this situation a main part of an inner surface 2 of the packaging sheet 1 abuts the cheese 15. Then a transparent shrink film sheet 16 is wrapped in the same conventional manner to enclose the cheese 15 wrapped in the packaging sheet 1. The shrink film or shrink wrap is of a conventional type, which gains an adhesive effect when being heated so that the shrink film in the resultant package adheres to the outer surface 9 of the resultant cheese package 20 and also maintains a structural integrity of the cheese package as is known to the skilled person.

(15) Then the external shrink film sheet 16 is provided with a rectangular paper label 17, preferably using a label application machine. The label 17 is suitable for displaying information regarding the cheese 15. The label 17 has an outer side 18 and an inner side 19. The inner side 19 is configured for facing the cheese 15. An adhesive (not shown) is provided on the inner side 19 of the label 17. The edges (not shown) of the external layer 16 and/or the packaging sheet 1 are connected on an upper side of the cheese package 20 by means of the label 17, which in a conventional manner is applied onto the sheet edges that are all assembled near a center of an upper surface of the cheese package 20, see FIG. 5. Thereby the cheese 15 is sealed from the environment and forms the resultant closed cheese package 20.

(16) Note that FIG. 4 shows the package 20 with a rectangular cross sectional shape. Usually the package will of course have softer edges that follow the curved outer peripheral surface of the cheese 15 so that the package may more resemble an ellipse in the cross section shown.

(17) The cheese package may have other sizes such as for example substantially triangular when seen from above to include a substantially triangular piece of cheese. In another embodiment a round cheese similar to the one shown in FIG. 5 is divided into a number of substantially triangular cheese pieces that may each be individually wrapped in a package sheet and positioned in a shape as shown in FIG. 5 after which the wrapped cheese pieces, which may be positioned in a tray to keep their mutual positions, are wrapped with a shrink film in the exact same manner as described above in connection with FIG. 5.

(18) FIG. 6 illustrates an embodiment of the method according to the invention for manufacturing a packaging sheet 1 according to any one of the above embodiments. In the following each step of the method will be described in sequence.

(19) In step 100 the packaging sheet 1 is provided. In step 300 the coloured layer 7 is printed on the first surface 5 of the paper layer 4 in a conventional method for printing on paper, the skilled person being able to choose a suitable method. In step 400 the polymer layer 8 is coated in a conventional manner directly onto the second surface 6 of the paper layer 4, which provides adherence between the two layers. This coating step may also be performed in a conventional manner. The adhesive layer 14 of the embodiment of FIG. 3 may optionally be coextruded with the polymer layer 8 in step 400 to provide improved adhesion. Alternatively, the polymer layer 8 may be an ethylene-methyl acrylate copolymer lacquer of a type which is obtained by emulsifying ethylene-methyl acrylate copolymer in water as shown in FIG. 2 in which case the second surface 6 of the paper layer 4 is coated by applying the ethylene-methyl acrylate copolymer lacquer onto it. This lacquer 13 is applied onto the paper layer 4 in a liquid form and may for example be applied using flexographic printing or using a smooth roller. It may alternatively be sprayed onto the paper layer 4 or applied using a blade. When the lacquer has been applied in a suitable, substantially uniform thickness across the entire surface 6, it is allowed to dry and harden. Finally, in step 600 a roller with a surface roughness may be applied to emboss the inner surface 2 of the packaging sheet 1 to increase the surface roughness of the inner surface 2. After this step the resultant packaging sheet 1 is usually rolled up to form a roll with a large length of sheet. Then the roll may be stored until it is transported to a cutting machine in which the length of sheet is rolled off of the roll and guided into a cutting machine, which via cutting blades cuts the sheet 1 into several (pieces of) packaging sheets of desired shapes and sizes. The resultant multiplicity of (pieces of) packaging sheets 1 may then be stacked into stacks of several hundred sheets and may be stored or transported to a manufacturing line for wrapping or packaging cheese in a manner as described above.

(20) Although some embodiments have been described and shown in detail herein, the invention is not restricted to them, but may also be embodied in other ways within the scope of the subject matter defined in the following claims. In particular, it is to be understood that other embodiments may be utilised and structural and functional modifications may be made without departing from the scope of the present invention.

(21) In device claims enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims or described in different embodiments does not indicate that a combination of these measures cannot be used to advantage.

(22) It should be emphasized that the term “comprises/comprising” 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.