Packaging container and method for manufacturing packaged food packaged in said packaging container

Abstract

To provide a packaging container including a container body for storing an article and a top seal for sealing the container body and having a printing layer difficult to be peeled when the top seal is peeled.SOLUTION: A packaging container 2 includes: a container body 4 which defines a storage space 34 having an upper opening; and a top seal 6 bonded to the container body to be peelable and adapted to seal the upper opening. The container body includes a base body 12 having a recess 24 in an upper surface, a first laminate film 14 made of a transmissive material, having a printing layer 30 provided to a rear surface, and joined to the upper surface of the base body on the rear surface, and a second laminate film 16 made of a transmissive material and joined to the upper surface of the first laminate film. A bond strength between the first laminate film and the base body is larger than that between the first laminate film and the second laminate film.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging container including a container body for containing an item and a top seal that is peelably attached to the container body and seals the container body, and a method for producing a packaged food packaged in the packaging container. [Background technology]

[0002] A container body that can be sealed with a top-sealing lid is known (for example, Patent Document 1). The container body in Patent Document 1 is made of polystyrene foam and has a bottom, a side part standing from the outer periphery of the bottom, and a flange part extending outward from the upper end of the side part. The flange part has a flat part with a width of 4 mm or more around the entire periphery, and the top-sealing lid is heat-welded within the width of the flat part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-164084 A Summary of the Invention [Problem to be solved by the invention]

[0004] In order to highlight the food contained in the container body, a printed layer including a pattern, letters, etc. may be provided on the container body. However, when the top seal (the top seal lid material) is peeled off after the top seal is heat-welded to the container body, the printed layer may peel off at the welded portion between the flange and the top seal. This peeling of the printed layer causes a problem of degrading the design of the container body.

[0005] In view of the above problems, the problem that the present invention aims to solve is to provide a packaging container that includes a container body for containing an item and a top seal for sealing the container body, in which a printed layer is not easily peeled off when the top seal is peeled off, and a method for manufacturing a packaged food packaged in the packaging container. [Means for solving the problem]

[0006] The packaged food according to the present invention is a packaging container (2) including a container body (4) defining an upper opening storage space (34), and a top seal (6) peelably adhered to the container body and sealing the upper opening, the container body having a base (12) with a recess (24) on its upper surface, a first laminate film (14) made of a permeable material and having a printing layer (30) on its back surface and joined to the upper surface of the base at its back surface, and a second laminate film (16) made of a permeable material and joined to the upper surface of the first laminate film, and the bonding strength between the first laminate film and the base is greater than the bonding strength between the first laminate film and the second laminate film.

[0007] According to this configuration, the adhesive strength between the first laminate film and the base is greater than the adhesive strength between the first laminate film and the second laminate film, so that when the top seal is peeled off, the second laminate film is peeled off from the first laminate film before the first laminate film is peeled off from the base, thereby preventing the first laminate film from being peeled off from the base and protecting the printed layer provided on the back surface of the first laminate film.

[0008] In the above embodiment, preferably, the first laminate film is welded to the base, and the second laminate film is adhered to the first laminate film.

[0009] According to this configuration, the adhesive strength between the first laminate film and the substrate can be made greater than the adhesive strength between the first laminate film and the second laminate film.

[0010] In the above embodiment, the first laminate film and the second laminate film are preferably formed from the same material.

[0011] According to this configuration, the first laminate film and the second laminate film are made of the same material, so that they can be easily adhered to each other.

[0012] In the above embodiment, preferably, the base is made of filler-containing polypropylene, and the first laminate film and the second laminate film are each made of polypropylene.

[0013] This arrangement results in cheaper packaged food.

[0014] In the above embodiment, the top seal is preferably thermocompression bonded to the second laminate film.

[0015] According to this configuration, when the top seal is thermocompression bonded to the second laminate film, a weak portion can be formed in the second laminate film. This allows the second laminate film to be broken at the weak portion when the top seal is peeled off, making it easier for the second laminate film to be separated from the first laminate film. Therefore, when the top seal is peeled off, the first laminate film is prevented from being peeled off from the base, and the printed layer can be protected.

[0016] In the above embodiment, the base preferably comprises a horizontal bottom wall, a peripheral wall erected on the outer peripheral edge of the bottom wall, and a flange portion extending horizontally from the upper edge of the peripheral wall, and the second laminate film and the top seal are joined above the flange portion.

[0017] This configuration makes it easier to join the top seal to the second laminate film.

[0018] The present invention is a method for manufacturing a packaged food packaged in a packaging container (2) including a container body (4) defining a storage space with an upper opening, and a top seal (6) peelably adhered to the container body and sealing the upper opening, the container body having a base (12) with a recess (24) on its upper surface, a first laminate film (14) made of a permeable material, having a printed layer on its back surface and bonded to the upper surface of the base at its back surface, and a second laminate film (16) made of a permeable material and bonded to the upper surface of the first laminate film, the manufacturing method including the steps of welding the first laminate film to the base, adhering the second laminate film to the first laminate film, accommodating food (38) in the storage space, and thermocompression-bonding the top seal to the second laminate film with the food accommodated therein.

[0019] According to this configuration, the adhesive strength between the first laminate film and the base is greater than the adhesive strength between the first laminate film and the second laminate film, so that the printed layer provided on the upper surface of the base is protected. Furthermore, when the top seal is thermocompressed to the second laminate film, a weak portion can be formed in the second laminate film. This allows the second laminate film to be broken at the weak portion when the top seal is peeled off, so that the second laminate film is easily separated from the first laminate film. Therefore, the first laminate film can be prevented from being peeled off from the base, so that the printed layer provided on the back surface of the first laminate film can be better protected.

[0020] In the above embodiment, preferably, in the process of joining the top seal to the upper surface of the second laminate film, the top seal and the second laminate film are heat-pressed together while the frozen food is contained in the storage space.

[0021] According to this configuration, the temperature change applied to the second laminate film during heat welding is large, so that the weak portion formed in the second laminate film can be made weaker.

[0022] In the above embodiment, the first laminate film and the second laminate film are preferably formed from the same material.

[0023] According to this configuration, the first laminate film and the second laminate film are made of the same material, so that they can be easily adhered to each other.

[0024] In the above embodiment, preferably, the base is made of filler-containing polypropylene, and the first laminate film and the second laminate film are each made of polypropylene.

[0025] This arrangement results in cheaper packaged food.

[0026] In the above embodiment, the base preferably comprises a horizontal bottom wall (18), a peripheral wall (20) erected on the outer periphery of the bottom wall, and a flange portion (22) extending horizontally from the upper edge of the peripheral wall, and the second laminate film and the top seal are joined above the flange portion.

[0027] This configuration makes it easier to join the top seal to the second laminate film. Effect of the Invention

[0028] According to the present invention, it is possible to provide a packaged food comprising a food, a container body for containing the food, and a top seal for sealing the container body, in which a printed layer is not easily peeled off when the top seal is peeled off, and a method for manufacturing the packaged food. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a perspective view of a packaged food product according to the present invention; [Diagram 2] Cross-sectional view of Fig. 1 along line II-II [Diagram 3] FIG. 1 is an explanatory diagram for explaining the first half of the manufacturing process of the packaged food according to the present invention. [Figure 4] FIG. 1 is an explanatory diagram for explaining the latter half of the manufacturing process of the packaged food according to the present invention. [Diagram 5] An enlarged view of the area enclosed by the dashed double-dashed line in Figure 4. [Figure 6] FIG. 1 is an explanatory diagram for explaining the steps a user takes when eating food contained in a packaged food according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, an embodiment of a packaging container according to the present invention and a method for producing a packaged food packaged in the packaging container will be described with reference to the drawings.

[0031] As shown in FIG. 1, a packaging container 2 according to the present invention is used for packaging items such as food, and includes a tray-shaped container body 4 and a top seal 6 that seals the container body 4.

[0032] 2, the container body 4 is configured as a multilayer structure made up of a plurality of layers. More specifically, the container body 4 includes a base 12 forming the bottom layer, a first laminate film 14 forming a layer bonded to the upper surface of the base 12, and a second laminate film 16 forming a layer bonded to the upper surface of the first laminate film 14.

[0033] The base 12 is formed of a composite material (PPF, filler-containing polypropylene) in which a filler is kneaded with a polypropylene base material. The filler may be talc, which is an inorganic powder. The base 12 has a rectangular bottom wall 18 extending substantially horizontally, a peripheral wall 20 erected on the outer periphery of the bottom wall 18, and a flange portion 22 extending substantially horizontally from the upper edge of the peripheral wall 20. The bottom wall 18 and the peripheral wall 20 define a recess 24 on the upper surface of the base 12, which is open upward and recessed downward. As shown in FIG. 1, the recess 24 is provided with a partition wall 26 extending substantially horizontally.

[0034] The first laminate film 14 is made of a material having transparency. In this embodiment, the first laminate film 14 is made of non-oriented polypropylene (CPP). The back surface of the first laminate film 14 is printed. In other words, a print layer 30 is provided on the back surface of the first laminate film 14. In this embodiment, the back surface of the first laminate film 14 is printed with a wood grain pattern when viewed from above over the entire surface.

[0035] 2, the back surface of the first laminate film 14 is bonded to the upper surface of the base 12, including the upper surface of the bottom wall 18, the inner surface of the peripheral wall 20, and the upper surface of the flange portion 22. In this embodiment, the first laminate film 14 is welded to the base 12.

[0036] The welding here refers to a bonding method in which a thermoplastic sheet or the like is heated and melted, preferably bonded by applying pressure, and then cooled to bond. When the first laminate film 14 is welded to the base 12, the back surface of the first laminate film 14 is heated at least until it reaches or exceeds the melting point.

[0037] The second laminate film 16 is formed of a material having the same transparency as the first laminate film 14. In this embodiment, the second laminate film 16 is made of non-oriented polypropylene (CPP). The back surface (lower surface) of the second laminate film 16 is joined to the entire upper surface of the first laminate film 14. In this embodiment, the second laminate film 16 is adhered (dry laminated) to the entire upper surface of the first laminate film 14 by an adhesive. The back surface of the second laminate film 16 is not printed and is a colorless and transparent film. This allows the wood grain pattern applied to the first laminate film 14 to be seen through the second laminate film 16.

[0038] By joining the first laminate film 14 and the second laminate film 16 inside the recess 24, a storage space 34 having an opening 32 that opens upward (i.e., an upward opening) is defined in the container body 4. The storage space 34 is divided into a plurality of spaces 34A to 34D by the partition wall 26. It is preferable that the upper surface of the partition wall 26 is lower than the upper surface of the flange portion 22.

[0039] The top seal 6 is a colorless, transparent film made of polypropylene (PP). The top seal 6 is peelably attached to the upper surface of a portion of the second laminate film 16 located above the flange portion 22 (more specifically, a portion of the second laminate film 16 bonded to a portion of the first laminate film 14 bonded to the upper surface of the flange portion 22). In this embodiment, the top seal 6 is thermocompression bonded to the second laminate film 16 around the entire periphery of the opening 32, sealing the entire opening 32. However, the top seal 6 may be attached to the second laminate film 16 with an adhesive.

[0040] The term "thermocompression bonding" as used herein refers to a method of bonding by heating the materials to be bonded to a predetermined temperature below their melting points and applying pressure to cause plastic deformation. When the top seal 6 is thermocompression bonded to the second laminate film 16, both the top seal 6 and the second laminate film 16 are heated to a predetermined temperature below their melting points and bonded by applying pressure to the materials.

[0041] In this embodiment, the top seal 6 is larger than the second laminate film 16 and includes a portion extending substantially horizontally from above the outer edge of the second laminate film 16. A tab 36 that is not bonded to the second laminate film 16 is formed at the end of the top seal 6.

[0042] The first laminate film 14 and the substrate 12 are heat-welded, and the first laminate film 14 and the second laminate film 16 are bonded with an adhesive, so that the bonding strength between the first laminate film 14 and the substrate 12 is greater than the bonding strength between the first laminate film 14 and the second laminate film 16. The bonding strength here indicates the strength of the bond between the two joined surfaces. The bonding strength is the tensile load per unit area required for the joined portion to peel off when a load is applied in a direction away from the joined surfaces, and may be the so-called peel strength (peel adhesive strength).

[0043] Furthermore, the bonding strength between the second laminate film 16 and the top seal 6 is greater than the bonding strength between the first laminate film 14 and the second laminate film 16 .

[0044] 1 and 2, food 38 is accommodated in accommodation space 34. This results in a packaged food 40 that includes packaging container 2 and food 38 packaged in packaging container 2. In this embodiment, accommodation space 34 accommodates frozen food 38A that can be eaten after heating in a microwave oven.

[0045] Next, a method for producing packaged food 40 will be described with reference to Figures 3 and 4. As shown in Figure 3(A), an operator processes a PPF sheet into a base 12, and then welds the back surface of a first laminate film 14, which has a printed layer 30 provided on its back surface, to the base 12. Thereafter, as shown in Figure 3(B), an operator adheres a second laminate film 16, which has an adhesive applied to its back surface, to the first laminate film 14. This completes the container body 4, as shown in Figure 4(A).

[0046] 4(A), the worker places food 38 in storage space 34 of container body 4. However, when food 38 is frozen food 38A, the worker may cool food 38 and container body 4 to a low temperature (−18° C. or lower) and place food 38 in storage space 34 at that low temperature.

[0047] Next, as shown in FIG. 4(B), the worker places the top seal 6 so as to seal the opening 32, and heats the portion of the top seal 6 located above the flange portion 22 using a tool 42 while pressing the top seal 6 against the second laminate film 16, thereby thermocompressing the top seal 6 to the second laminate film 16. At this time, the worker may heat the top seal 6 while cooling the container body 4 and the food 38 to a low temperature (below -18°C) to prevent the temperature of the food 38 from increasing. Furthermore, the worker may blow nitrogen gas or carbon dioxide gas into the storage space 34 to perform thermal welding of the top seal 6 in a nitrogen or carbon dioxide atmosphere. At this time, as shown in FIG. 5, a fragile portion 44 that is more easily broken than other portions is formed in the vicinity of the connection portion between the flange portion 22 of the second laminate film 16 and the peripheral wall 20 due to temperature changes during thermal welding or the temperature difference between the thermally welded portion and the external environment. Once the heat welding of the top seal 6 is complete, the production of the packaged food product 40 is complete.

[0048] When eating food 38, a user first heats packaged food 40 in a microwave oven. Heating in the microwave oven makes fragile portion 44 more easily ruptured. Then, the user pinches tab 36 with his or her fingers to peel off top seal 6. This causes peeling between first laminate film 14 and second laminate film 16, as shown in FIG. 6(A), and top seal 6 is lifted together with second laminate film 16. Then, as shown in FIG. 6(B), second laminate film 16 is ruptured at fragile portion 44, and first laminate film 14 and top seal 6 are separated. This opens storage space 34, and packaging container 2 is opened. This allows the user to take out food 38 (see FIG. 4(B)) from storage space 34 and eat it.

[0049] Next, the effects of the manufacturing method of the packaging container 2 and the packaged food 40 will be described. The first laminate film 14 and the base 12 are heat-sealed, and the first laminate film 14 and the second laminate film 16 are bonded by an adhesive. This makes it possible to make the bonding strength between the first laminate film 14 and the base 12 greater than the bonding strength between the first laminate film 14 and the second laminate film 16. This allows the user to lift the knob 36 with his or her fingers, and the second laminate film 16 is peeled off from the first laminate film 14 without peeling the first laminate film 14 off from the base 12. This protects the print layer 30 provided on the back surface of the first laminate film 14.

[0050] The first laminate film 14 and the second laminate film 16 are formed of CPP. By making the first laminate film 14 and the second laminate film 16 from the same material in this way, the two films become more compatible with each other and are more easily adhered to each other. In addition, since the base 12 is made of polypropylene containing filler and the first laminate film 14 and the second laminate film 16 are both made of polypropylene, the packaging container 2 can be manufactured at low cost.

[0051] When the top seal 6 is heat-sealed to the second laminate film 16, the second laminate film 16 is rapidly heated. As a result, as shown in FIG. 5, a fragile portion 44 is formed in the second laminate film 16 at the portion bonded to the top seal 6 and in the vicinity thereof, i.e., in the vicinity of the flange portion 22. As a result, when a user picks up the tab 36 with his / her fingers, as shown in FIG. 6(B), the second laminate film 16 is broken in the vicinity of the flange portion 22, and the portion of the second laminate film 16 on the tab 36 side can be separated from the first laminate film 14. Therefore, when the top seal 6 is peeled off, the first laminate film 14 is prevented from peeling off from the base 12, and the printed layer 30 can be protected.

[0052] Furthermore, in this embodiment, since the top seal 6 and the second laminate film 16 are thermally bonded in a low-temperature environment, the weak portion 44 formed in the portion of the second laminate film 16 bonded to the top seal 6 and in the vicinity thereof can be made weaker than when the second laminate film 16 is thermally bonded in a room temperature environment. This makes the weak portion 44 of the second laminate film 16 more likely to break. Therefore, the portion of the second laminate film 16 on the tab portion 36 side can be more easily separated from the first laminate film 14, and the printed layer 30 can be protected.

[0053] The present invention has been described above with reference to its preferred embodiments. However, as will be easily understood by those skilled in the art, the present invention is not limited to such embodiments, and can be modified as appropriate without departing from the spirit of the present invention.

[0054] In the above embodiment, the printed layer 30 is provided on the back surface of the first laminate film 14, but the present invention is not limited to this embodiment. For example, the printed layer 30 may be provided on the upper surface of the base 12. In the above embodiment, an example in which food 38 is contained in the packaging container 2 is described, but the present invention is not limited to this embodiment. The packaging container 2 may contain an item other than food 38.

[0055] Furthermore, not all of the components shown in the above embodiment are necessarily essential, and they can be appropriately selected without departing from the spirit of the present invention. [Explanation of symbols]

[0056] 2: Packaging container 4: Container body 6: Top seal 12: Base 14: First lamination film 16: Second lamination film 18: Bottom wall 20: Peripheral wall 22: Flange part 24: Recess 26: Partition wall 30: Printing layer 32: Opening 34: Containment space 34A: Space 34B: Space 34C: Space 34D: Space 36: Knob 38:Food 38A: Frozen foods 40:Packaged food 42: Tools 44: Weakened part

Claims

1. A packaging container including a container body defining an upper opening of a storage space, and a top seal releasably attached to the container body to seal the upper opening, The container body includes: A base having a recess on an upper surface and a printing layer on the upper surface; a first laminate film made of a transparent material and bonded at its back surface to the upper surface of the base; a second laminate film made of a transparent material and bonded to an upper surface of the first laminate film; A packaging container, wherein the bonding strength between the first laminate film and the substrate is greater than the bonding strength between the first laminate film and the second laminate film.

2. the first laminate film is welded to the substrate; The packaging container according to claim 1 , wherein the second laminate film is adhered to the first laminate film.

3. 3. The packaging container according to claim 2, wherein the first laminate film and the second laminate film are made of the same material.

4. The substrate is made of filler-containing polypropylene, The packaging container according to claim 3 , wherein the first laminate film and the second laminate film are each made of polypropylene.

5. The packaging container according to any one of claims 2 to 4, wherein the top seal is heat-pressed to the second laminate film.

6. The base body includes a horizontal bottom wall, a peripheral wall provided on an outer peripheral edge of the bottom wall, and a flange portion extending horizontally from an upper edge of the peripheral wall, The packaging container according to any one of claims 1 to 5, wherein the second laminate film and the top seal are joined above the flange portion.

7. A method for producing a packaged food packaged in a packaging container including a container body defining an upper opening of a storage space, and a top seal releasably attached to the container body and sealing the upper opening, comprising: The container body includes: A base having a recess on an upper surface and a printing layer on the upper surface; a first laminate film made of a transparent material and bonded at its back surface to the upper surface of the substrate; a second laminate film made of a transparent material and bonded to an upper surface of the first laminate film; The manufacturing method includes: welding the first laminate film to the substrate; Adhering the second laminate film to the first laminate film; storing food in the storage space; and heat-pressing the top seal to the second laminate film while the food is contained therein.

8. A method for producing packaged food as described in claim 7, wherein in the process of joining the top seal to the upper surface of the second laminate film, the top seal and the second laminate film are heat-pressed together while the frozen food is contained in the storage space.

9. 9. The method for producing a packaged food according to claim 7 or 8, wherein the first laminate film and the second laminate film are formed from the same material.

10. The substrate is made of filler-containing polypropylene, The method for producing packaged food according to claim 9, wherein the first laminate film and the second laminate film are each made of polypropylene.

11. The base body includes a horizontal bottom wall, a peripheral wall provided on an outer peripheral edge of the bottom wall, and a flange portion extending horizontally from an upper edge of the peripheral wall, The method for producing a packaged food according to any one of claims 7 to 10, wherein the second laminate film and the top seal are joined above the flange portion.

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