Paper containers

Abstract

To provide a paper container capable of containing contents, and of taking out the contained contents without leaving any residue.SOLUTION: A paper container 10 is composed of a paper container main body 11 and a plastic film 12. The paper container main body 11 has a bottom surface 11a and a side wall 11b rising from a peripheral edge of the bottom surface 11a, in which a space surrounded with the bottom surface 11a and the side wall 11b serves as a content containing portion. A flange 11c is provided around an upper end of the side wall 11b of the paper container main body 11. On the other hand, the plastic film 12 has a thickness of 30 to 500 μm, and a peripheral edge thereof is fixed to the flange 11c of the paper container main body, and a central portion thereof is slackened toward an inside of the content containing portion of the paper container main body 11. In addition, the plastic film 12 has a gap with the bottom surface 11a of the paper container main body 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a paper container that can store contents and from which the stored contents can be removed without leaving any residue. [Background technology]

[0002] Tray-shaped containers and cup-shaped containers made of a paper container body and a plastic film are well known and are described in Patent Documents 1 and 2, for example.

[0003] These tray-shaped paper containers and cup-shaped paper containers have a bottom and side walls that rise from the periphery of the bottom, and the bottom and side walls intersect to form corners. Therefore, when trying to remove the contents from these tray-shaped paper containers or cup-shaped paper containers with, for example, a spoon, some of the contents remain in the corners, making it impossible to remove all of the contents.

[0004] Furthermore, even if the contents are placed in the center, avoiding the corners, the vibrations during transport can cause the contents to lose their shape and move to the corners, making it impossible to remove all of the contents. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-6071 [Patent Document 2] Japanese Patent Application Publication No. 2019-1494 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, an object of the present invention is to provide a paper container that can store contents and from which the stored contents can be removed without leaving any residue. [Means for solving the problem]

[0007] That is, the invention described in claim 1 is composed of a paper container body and a plastic film, The paper container body has a bottom surface and a side wall rising from the peripheral edge of the bottom surface, and the space surrounded by the bottom surface and the side wall is used as a content storage section, and has a flange provided around the upper end of the side wall, The thickness of the plastic film is 30 to 500 μm, This paper container is characterized in that the peripheral edge of the plastic film is fixed to the flange of the paper container body, the central part of the plastic film is loosened toward the inside of the content storage section of the paper container body, and there is a gap between the plastic film and the bottom surface of the paper container body.

[0008] The plastic film is preferably heat-resistant so that it does not melt when heated in a microwave oven.

[0009] The paper container body may be a tray-shaped container having a polygonal cross section, or may be a circular cup-shaped container. [Effects of the Invention]

[0010] In this invention, the peripheral edge of the plastic film is fixed to the flange of the paper container body. The center of the paper container is positioned inside the content storage section of the paper container body, and since the center is loosened toward the inside of the content storage section of the paper container body, this loosening causes the center to have a curved surface.The contents placed on this curved center can be removed without leaving any behind by moving the contents along the curved center with, for example, a spoon.

[0011] Furthermore, by placing the contents in the loosened center of the plastic film, even if vibrations are applied during transportation, the loosened plastic film absorbs the vibrations, preventing the contents from losing their shape.

[0012] Furthermore, because the thickness of the plastic film is 30 to 500 μm, the plastic film will not tear when the contents are scooped up with a spoon or the like, and even when subjected to vibrations during transportation, the plastic film will not tear and the contents will not lose their shape.

[0013] Furthermore, if the plastic film is heat-resistant and does not melt when heated in a microwave oven, the contents can be placed in the center of the plastic film and heated in a microwave oven. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an explanatory cross-sectional view of a paper container according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a paper container according to an embodiment of the present invention will be described with reference to the accompanying drawings, in which Fig. 1 is an explanatory cross-sectional view.

[0016] As can be seen from FIG. 1, the paper container 10 is composed of a paper container body 11 and a plastic film 12.

[0017] The paper container body 11 has a bottom surface 11a and a side wall 11b that rises from the periphery of the bottom surface 11a, and the space surrounded by the bottom surface 11a and the side wall 11b serves as a content storage section. The paper container body 11 also has a flange that protrudes from the upper end of the side wall 11b toward the outside of the paper container body 11.

[0018] The paper container body 11 may be a tray-shaped container formed by folding the paper that constitutes it, or a cup-shaped container in which a single sheet of paper is rolled up to form the side wall 11b. Generally, the cross section of a tray-shaped container is polygonal, while the cross section of a cup-shaped container is circular. In either case, the side wall 11b does not need to rise vertically from the periphery of the bottom surface 11a, and may rise diagonally outward from the periphery of the bottom surface 11a, as shown in the figure.

[0019] The paper container body 11 can be formed by folding or rolling a single-layer or multi-layer blank including paperboard. The structure and assembly method thereof may be well known.

[0020] The paperboard constituting the paper container body 11 has a basis weight of 100 to 500 g / m 2 The preferred basis weight is 190 to 350 g / m 2 It is a cardboard of this size.

[0021] As will be described later, in the paper container 10 of the present invention, the contents 20 do not come into contact with the paper container body 11, so the paper container body 11 can be constructed from a blank made of paperboard alone. However, in addition to this, the blank can also be constructed from a multi-layer sheet laminated with other resins or metal foils. Examples of resins that can be laminated on the paperboard include polyethylene resin, Examples of the metal foil include polypropylene resin, polyester resin, and polyamide resin. Alternatively, the metal foil may be a vapor-deposited film having a metal vapor deposition film or an aluminum oxide vapor deposition film formed thereon. A typical example of the metal foil is aluminum foil.

[0022] Next, the plastic film 12 is arranged like a hammock inside the paper container body 11, and serves to suspend the contents 20 so that they do not come into contact with the paper container body 11. For this reason, the periphery of this plastic film 12 is adhesively fixed to the flange 11c of the paper container body 11, and its center is loosened toward the inside of the content storage section of the paper container body 11. Furthermore, when vibrations are applied to the paper container 10 during transportation, etc., a gap is provided between the plastic film 12 and the bottom surface 11a of the paper container body 11 to prevent these vibrations from being transmitted to the contents 20. By providing this gap between the contents 20 placed in the center of the plastic film 12 and the bottom surface 11a of the paper container body 11, even when vibrations are applied to the paper container 10, the plastic film 12 absorbs the vibrations and prevents them from reaching the contents 20.

[0023] This plastic film 12 can be a single-layer or multi-layer film with a thickness of 30 to 500 μm. If the thickness is less than 30 μm, the film 12 may be torn by an accidental contact with a spoon or the like when scooping up the contents with the spoon. It may also be torn by vibrations during transportation. On the other hand, if the thickness exceeds 500 μm, the flexibility of the film 12 is poor, and therefore the contents 20 may lose their shape due to vibrations during transportation.

[0024] The plastic film 12 may be a stretched film or a non-stretched film, but is preferably a stretched film.

[0025] Furthermore, the plastic that constitutes plastic film 12 may be any plastic, but if microwave heating is expected, it is desirable that the plastic be heat resistant so that it will not melt when heated in a microwave. For example, polypropylene resin, ethylene-vinyl alcohol resin, or polyester resin. If plastic film 12 has a multilayer structure and microwave heating is expected, it is desirable that all plastics that constitute plastic film 12 be heat resistant so that they will not melt when heated in a microwave.

[0026] Furthermore, when the plastic film 12 has a multilayer structure, a layer having oxygen barrier properties or water vapor barrier properties can be provided as part of the layer structure. For example, the above-mentioned ethylene-vinyl alcohol resin is known to have oxygen barrier properties.

[0027] This paper container 10 can be used as follows. That is, as shown in Fig. 1, the contents 20 are placed in the center of the plastic film 12 and transported as is. For example, a product such as mapo tofu cooked in a store can be placed inside the paper container 10 as the contents 20, and the contents 20 can be brought home without losing their shape. Furthermore, if the contents are to be cooked in a microwave oven, the plastic film 12 is heat-resistant, so the contents can be cooked while still contained in the paper container 10. [Example]

[0028] The present invention will be explained below with reference to examples. In these examples and comparative examples, the layer structure and thickness of the plastic film 12 were changed to investigate whether the contents could be completely removed with a spoon, whether the plastic film 12 would tear or the contents would lose their shape due to vibrations during transportation, and whether the plastic film 12 would tear when heated in a microwave oven. For this reason, the same tray-shaped paper container was used as the paper container body 11 in both the examples and comparative examples.

[0029] Example 1 A single-layer film made of heat-sealable polyester film (HS-PET) was used as the plastic film 12. This film has heat resistance so that it does not melt when heated in a microwave oven. Its thickness is 100 μm.

[0030] Example 2 A single-layer film made of HS-PET, the same as in Example 1, was used, except that the thickness was set to 50 μm.

[0031] Example 3 A three-layer co-extruded multilayer film was used as the plastic film 12. The layer structure is symmetrical on the front and back, with polypropylene (PP), ethylene-vinyl alcohol copolymer (EVOH), and polypropylene (PP) laminated in that order. This film is heat-resistant and will not melt when heated in a microwave oven. The thickness is 100 μm.

[0032] Example 4 A film having the same three-layer structure as in Example 3 was used, except that the thickness was set to 50 μm.

[0033] Example 5 A single-layer film made of polyethylene (PE) was used as the plastic film 12. This film does not have heat resistance and does not melt when heated in a microwave oven. Its thickness is 50 μm.

[0034] (Comparative Example 1) As in Example 3, a single-layered film made of HS-PET was used as the plastic film. However, this film was attached to the inside surface of the paper container body 11, and of course, the center portion was not loose, and there was no gap between this film and the bottom surface 11a of the paper container body 11. Furthermore, this film was heat-resistant so that it would not melt when heated in a microwave oven. Its thickness was 50 μm.

[0035] (Comparative Example 2) As in Example 4, a three-layer film made of PP, EVOH, and PP laminated in that order was used as the plastic film. However, this film was attached to the inside surface of the paper container body 11, and of course, the center portion was not loose, and there was no gap between this film and the bottom surface 11a of the paper container body 11. Furthermore, this film was heat-resistant so that it would not melt when heated in a microwave oven. Its thickness was 50 μm.

[0036] (Comparative Example 3) The plastic film used was a single-layer film made of HS-PET. This film is heat-resistant and will not melt when heated in a microwave oven. However, its thickness is 12 μm, thinner than 30 μm.

[0037] Comparative Example 4 The plastic film used was a three-layer film made of PP, EVOH, and PP laminated in that order. This film is heat-resistant and will not melt when heated in a microwave oven. However, its thickness was greater than 500 μm, at 800 μm.

[0038] (Comparative Example 5) The plastic film used was a single-layer film made of HS-PET. This film is heat-resistant and will not melt when heated in a microwave oven. However, its thickness is greater than 500 μm, at 800 μm.

[0039] (test) 200g of mapo tofu was placed in the center of the plastic film 12 of the tray-shaped paper containers of Examples 1 to 5 and Comparative Examples 1 to 5, and the tray-shaped paper containers were tested and evaluated from the following three perspectives: In Comparative Examples 1 and 2, 200g of mapo tofu was placed approximately in the center of the tray-shaped paper container. Residual amount: After the contents were scooped out with a spoon, the amount remaining in the tray-shaped paper container was evaluated. Transportation test: A collection transport test was conducted in a cardboard box based on JIS Z0200. A random vibration test was conducted, and items that lost their shape at level 1 were rated as "X", items that did not lose their shape were rated as "O", and items that were slightly distorted were rated as "△". Microwave oven: The plastic film 12 was heated in a microwave oven and evaluated for melting or not. Those that melted were evaluated as "x", and those that did not melt were evaluated as "o".

[0040] These results are shown in Table 1.

[0041] [Table 1] [Explanation of symbols]

[0042] 10:Paper containers 11: Paper container body 11a: Bottom surface 11b: Side wall 11c: Flange 12: Plastic film 20:Contents

Claims

1. It consists of a paper container body and a plastic film. The paper container body has a bottom surface and a side wall rising from the peripheral edge of the bottom surface, and the space surrounded by the bottom surface and the side wall is used as a content storage section, and has a flange provided around the upper end of the side wall, The thickness of the plastic film is 30 to 500 μm, The peripheral edge of the plastic film is fixed to the flange of the paper container body, the central part of the plastic film is loosened toward the inside of the content storage part of the paper container body, and a gap is provided between the central part of the plastic film and the bottom surface of the paper container body, The paper container is characterized in that the plastic film has heat resistance so that it does not melt or tear when heated in a microwave oven.

2. 2. The paper container according to claim 1, wherein the plastic film has oxygen barrier properties or water vapor barrier properties.

3. 3. The paper container according to claim 1, wherein the paper container body is a tray-shaped container.

4. 3. The paper container according to claim 1, wherein the paper container body is a cup-shaped container.

Images