JP2024084537A - Cold insulation packaging container and package - Google Patents

Abstract

To provide a packaging container with excellent cold insulation properties which can simplify packaging work.SOLUTION: A cold insulation packaging container includes a first sealing member 10 that has a first paper base material 10B and a first resin sheet 10A that covers at least a portion of the surface thereof, a second sealing member 20 that has a second paper base material 20B and a second resin sheet 20A that convers at least a portion of the surface thereof, and a resin bag body 30 that contains a to-be-packed object, a heat insulating member 42 surrounding it and the first sealing member 10. A folding 32 of the bag body 30 that is formed by being folded to seal the bag body 30 has a sealing structure 90 that is sandwiched between a covering surface 13 of the first resin sheet 10A of the first sealing member 10 and a covering surface 23 of the second resin sheet 20A of the second sealing member 20.SELECTED DRAWING: Figure 5

Description

This disclosure relates to a packaging container and a package for keeping things cool.

When storing and transporting food, beverages, and ingredients, etc., cold-keeping packaging containers are used to maintain quality and freshness. One such packaging container known to be made of polystyrene foam, which is lightweight and has relatively good cold-keeping properties (e.g., Patent Document 1). However, containers made of polystyrene foam are difficult to regenerate and recycle. For this reason, from the perspective of effective resource utilization, packaging containers using paper insulation material are being considered. For example, Patent Document 2 proposes a technology that uses defibrated material obtained by defibrating waste paper as insulation material.

JP 2015-52433 A JP 2022-62905 A

In order to maintain the insulation properties of a cold storage packaging container, it is necessary to use a combination of various components such as a box body, a bag body, and adhesive tape, which can easily make the packaging work complicated. On the other hand, the items to be packed in the cold storage packaging container need to be packed quickly to maintain their freshness and quality. Therefore, the present disclosure provides a packaging container and a package that have excellent cold storage properties and can simplify the packaging work.

One aspect of the present disclosure provides the following packaging container:

[1] A packaging device comprising: a first sealing member having a first paper base material and a first resin sheet covering at least a portion of its surface; a second sealing member 20 having a second paper base material and a second resin sheet covering at least a portion of its surface; an item to be packed and a heat insulating member surrounding the item; and a resin bag body that contains the first sealing member;
A packaging container for keeping things cold has a sealing structure in which a folded portion of a bag body formed by folding the bag body to seal it is sandwiched between a covered surface made of a first resin sheet of a first sealing member and a covered surface made of a second resin sheet of a second sealing member.

The above-mentioned packaging container has a sealing structure in which the folded portion of the bag body is sandwiched between the surface covered by the first resin sheet of the first sealing member and the surface covered by the second resin sheet of the second sealing member. This sealing structure has a folded portion, so the packaged object can be contained and sealed without welding or gluing the bag body. This allows the packaged object to be packed quickly and smoothly. In addition, since the sealing structure is formed by the resin sheet and the folded portion of the resin bag body, that is, by the resins being in close contact with each other, it is possible to sufficiently prevent cold air (gas) from leaking from the inside of the bag body to the outside. Therefore, the above-mentioned packaging container has excellent cold retention properties and can simplify the packaging work.

The packaging container of [1] above may be any one of [2] to [8] below.

[2] A cold storage packaging container as described in [1], comprising an outer box for housing the bag body, and the sealing structure is constrained by the outer box.
[3] The first sealing member is a lid that is placed over the upper end of the side wall portion formed by the insulating member 42, and together with the side wall portion forms a closed space for accommodating the packaged item. The cold storage packaging container described in [1] or [2].
[4] The cold storage packaging container described in any one of [1] to [3], wherein the second sealing member is a plate-shaped member arranged between the lid member that closes the outer box and the folding portion.
[5] A packaging container for cold storage described in any one of [1] to [4], in which dry ice is stored together with the items to be packed in the storage section surrounded by the insulating member.
[6] The packaging container for cold storage described in any one of [1] to [5], wherein the insulating member contains at least one of kitchen paper and molded pulp.
[7] The heat insulating member and the outer box are made of paper, in the packaging container for cold storage described in any one of [1] to [6].
[8] A packaging container for cold storage described in any one of [1] to [7], wherein the first resin sheet and the second resin sheet are made of polyethylene or polypropylene, and the bag body is made of high-density polyethylene.

The packaging container of [2] above includes an outer box that restrains the sealing structure. Therefore, for example, even if the internal pressure of the bag body rises, the function of the sealing structure having the folded portion can be maintained. That is, when the internal pressure inside the bag body rises, the first sealing member is pressed toward the second sealing member. Here, since the packaging container includes an outer box that restrains the sealing structure, the folded portion is pressed in a direction in which the two covering surfaces face each other. Therefore, the airtightness inside the bag body is maintained at a sufficiently high level, and as a result, the cold retention can also be maintained at a sufficiently high level. In this way, by including an outer box that restrains the sealing structure, it is possible to prevent the folded portion from loosening as the bag body expands, causing the sealing structure to fail.

In the packaging container of [3] above, the first sealing member serves as a lid for forming a closed space to accommodate the packaged item. This reduces the number of parts, lowers manufacturing costs, and further simplifies packaging operations. In [4] above, the second sealing member is a plate-shaped member, so that the size of the packaging container can be prevented from becoming too large while maintaining a sufficiently high level of cold insulation.

In the above [5], dry ice sublimes in the temperature environment used for normal packaging work, so if an attempt is made to pack the bag by tying or welding the opening, the bag will expand immediately, making the packing work difficult. In the above packaging container, the bag can be sealed by sandwiching the folded portion between two covering surfaces, so sealing the bag and assembling the packaging container can be completed almost simultaneously. Therefore, the packing work can be carried out smoothly even when storing dry ice.

In the above [6], the insulating material contained in the insulating member contains at least one of kitchen paper and pulp mold, so that the cold insulation can be further improved while reducing manufacturing costs. In the above [7], the insulating member and the outer box are made of paper, so that they can be recycled to make effective use of resources. In the above [8], the bag body is made of high-density polyethylene, which makes it easy to form the folded part, improves the sealing property, and can sufficiently increase the cold insulation property. In addition, since high-density polyethylene has a certain degree of gas permeability, when dry ice is used as a cooling material, it is possible to suppress the pressure inside the bag body from becoming excessively high while maintaining the sealing property. In addition, since the first resin sheet and the second resin sheet are made of polyethylene or polypropylene, the manufacturing cost can be sufficiently reduced.

One aspect of the present disclosure provides the following packaging:

[9] Provided is a package comprising a packaging container according to any one of [1] to [8] above, and an item to be packaged and dry ice contained in the packaging container.

The packaging body includes the packaging container described above. The bag body in the packaging container is sealed by sandwiching the folded portion between the covering surface of the first resin sheet of the first sealing member and the covering surface of the second resin sheet of the second sealing member. This maintains a sufficiently high level of airtightness within the bag body, and as a result, the cold retention properties can be maintained at a sufficiently high level. In addition, since the folded portion of the bag body can be sealed by sandwiching it between the two covering surfaces, the sealing of the bag body and the assembly of the packaging container can be completed almost simultaneously. Therefore, the packaging work can be performed smoothly even when dry ice is stored.

The package of the above [9] may be the following [10].
[10] The package described in [9], wherein the packaged items include at least one of frozen foods and frozen desserts.

The above-mentioned package has excellent cold insulation properties and can simplify the packaging process. For this reason, it is particularly useful for packaging frozen foods and frozen desserts, which require quick packaging and sufficient cold insulation properties.

This disclosure makes it possible to provide a packaging container and package that have excellent cold retention properties and can simplify packaging operations.

FIG. 1 is a perspective view of a packaging container (packaging body) according to one embodiment. FIG. 2 is an exploded perspective view of the packaging container (packaging body) of FIG. 1 . 4A and 4B are diagrams showing a bag body and a heat insulating member and a first sealing member housed therein. 4 is a cross-sectional view of the packaging container (packaging body) of FIG. 1 taken along line IV-IV. 5 is an enlarged cross-sectional view showing the folded portion of the bag body, the first sealing member, the second sealing member, and the vicinity thereof, in the cross-section shown in FIG. 4. FIG. 1 is a perspective view showing a side wall portion formed of a heat insulating member and a first sealing member that is placed to close the upper end side of the side wall portion. FIG. Photographs illustrating the manufacturing procedure of the packaging body of the embodiment are shown in (A) and (B). Photographs illustrating the manufacturing procedure of the packaging body of the embodiment are shown in (A) and (B). Photographs illustrating the manufacturing procedure of the packaging body of the embodiment are shown in (A) and (B). Photographs illustrating the manufacturing procedure of the packaging body of the embodiment are shown in (A) and (B). 13A and 13B are graphs showing the evaluation results of the cold retention properties of Examples 1 and 2 (changes in temperature over time). Graphs (A) and (B) show the evaluation results of the cold retention properties of Comparative Examples 1 and 2 (changes in temperature over time). Graphs (A) and (B) show the evaluation results of the cold retention properties of Examples 3 and 4 (changes in temperature over time).

An embodiment of the present disclosure will be described below, with reference to the drawings where appropriate. However, the following embodiment is an example for explaining the present disclosure, and is not intended to limit the present disclosure to the following content. In the description, the same reference numerals will be used for the same elements or elements having the same functions, and duplicated descriptions will be omitted where appropriate. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of each element are not limited to those shown in the drawings.

A cold storage packaging container 100 (package 200) according to one embodiment has an appearance as shown in FIG. 1, and can be disassembled as shown in FIG. 2 and FIG. 3. As shown in FIG. 1 to FIG. 3, the packaging container 100 (package 200) includes an outer box 60, an insulating member 42 housed in the bottom of the outer box 60, a resin bag body 30, and a second sealing member 20. The bag body 30 contains an insulating member 41 that forms a side wall, and a first sealing member 10 that functions as a lid that closes the storage section surrounded by the insulating member 41. The packaged object is housed in a closed space formed by the bag body 30 that is superimposed on the upper surface of the insulating member 41, the four insulating members 41 that form the side walls, and the first sealing member 10. That is, the bottom surface of the closed space that houses the packaged object is a part of the bag body 30, the side surfaces of the closed space are made of the insulating member 41, and the top surface is made of the first sealing member 10. From the viewpoint of recycling, the heat insulating members 41 and 42 may be made of paper material only. The heat insulating members 41 and 42 can be constructed by housing the heat insulating material in a box made of paperboard for paper containers such as corrugated cardboard and coated cardboard.

The insulating material preferably includes at least one of defibrated material containing cellulose fibers, kitchen paper, and molded pulp. As such, if the material is capable of containing gas (air) inside, it can sufficiently improve the cold retention. From the viewpoint of reducing manufacturing costs and simplifying the manufacturing process, the insulating material preferably includes at least one of kitchen paper and molded pulp, and from the viewpoint of further improving the cold retention, it is more preferable that the insulating material includes kitchen paper.

Examples of defibrated materials include those obtained by defibrating paper. Paper used as a raw material may be, for example, waste paper such as newspapers, books, magazines, catalogs, high-quality paper, packaging boxes, cardboard boxes, pulp molds, and paper cushioning materials. Equipment for obtaining defibrated materials from such raw materials may include commercially available dry defibration devices (defibrators) or wet defibrators, as appropriate. Defibrated materials may also be obtained using mills used for cooking at home. In addition to the defibrated cellulose fibers, the defibrated materials may contain additives such as paper powder, coloring materials such as ink and toner that were attached to the waste paper, and anti-bleeding agents. The defibrated cellulose fibers may be entangled with each other.

The outer box 60 may be, for example, a normal cardboard box. The top surface of the outer box 60 is configured to be openable, and a lid member 61 (flap) is connected to the upper ends of each of the four side walls 64, and the outer box 60 is closed by folding the lid member 61 inward. In the closed state, the lid member 61 may be fixed by adhering tape 66 in an H-shape. As shown in FIG. 1, the bottom surface of the outer box 60 may also be fixed by adhering tape 66.

2, the bag body 30 is accommodated on the insulating member 42 in the outer box 60. As shown in FIG. 3, the bag body 30 has an opening 24 at the top, and the insulating member 41 forming the side wall and the first sealing member 10 forming the lid body that covers the upper end of the insulating member 41 are accommodated inside the bag body 30 as one body. With the insulating member 41 and the first sealing member 10 accommodated, the upper part of the bag body 30 is folded to close the opening 24, and the folded part 32 as shown in FIG. 2 is formed to seal the bag body 30. The folded part 32 of the bag body 30 has a crease and is formed by overlapping the upper ends of the bag body 30. Such a folded part 32 is sandwiched between the upper surface (covering surface 13) of the first sealing member 10 and the lower surface (covering surface) of the second sealing member 20 as shown in FIG. 2 and FIG. 3. In this way, a sealing structure is formed in which the folded part 32 is sandwiched between the mutually opposing covering surfaces.

The bag body 30 is made of resin. Examples of resin include polyolefins such as low-density polyethylene (LDPE, LLDPE), high-density polyethylene (HDPE), polypropylene (PP), and nylon. Among these, polyolefins are preferred from the viewpoint of low cost, good foldability, and a certain degree of gas permeability, and among polyolefins, high-density polyethylene (HDPE) is more preferred. High-density polyethylene can suppress excessive increase in internal pressure even when a sublimating or vaporizing coolant such as dry ice is used as the coolant while maintaining high sealing properties at the folded portion 32. The gas permeability of carbon dioxide of the bag body 30 may be 10,000 to 300,000 mL/m ² ·d·MPa, or may be 20,000 to 200,000 mL/m ² ·d·MPa, from the viewpoint of sufficiently maintaining excellent cold insulation while suppressing excessive increase in internal pressure. This gas permeability can be measured in an environment of 20° C. and 65% RH in accordance with JIS K 7126-1.

As shown in FIG. 4, the first sealing member 10 is placed over the upper end of the side wall portion formed by the insulating member 42, and makes the storage section 72 taken in by the side wall portion (insulating member 41) into a closed space. In this way, the first sealing member 10 functions both as a lid and as a sealing member that sandwiches and seals the folding section 32. The storage section 72 in FIG. 4 may contain the packaged item and a cooling material such as dry ice. The bag body 30 is interposed between the outer box 60 and the insulating member 41 and is exposed at the bottom surface of the storage section 72. The upper part of the bag body 30 is folded to form the folding section 32.

As shown in FIG. 4, the folding portion 32 is sandwiched between the first sealing member 10 (covered surface 13) and the second sealing member 20 (covered surface 23). The packaging container 100 (packaged body 200) has a sealing structure 90 in which the folding portion 32 is sandwiched between the covered surface 13 of the first resin sheet of the first sealing member 10 and the covered surface 23 of the second resin sheet of the second sealing member 20. The sealing structure 90 is surrounded by an outer box 60. The lid member 61 of the outer box 60 is fixed with tape 66, such as craft tape. The sealing structure 90 is restrained by the outer box 60 so that the covered surface 13, the folding portion 32, and the covered surface 23 are kept in close contact with each other.

The packaging container 100 (packaging body 200) has a sealing structure 90, which allows for sufficiently high airtightness. The areas of the covering surface 13 and the covering surface 23 may be approximately the same, and their centers may be aligned with each other. The outer edge of the covering surface 23 may be in contact with the inner wall of the outer box 60. This allows for even higher airtightness.

Although FIG. 4 does not show the packaged object and the cooling material contained in the storage section 72, the storage section 72 may store dry ice together with the packaged object. In this case, as the dry ice sublimes, the internal pressure of the bag body 30, which is a closed space, increases, and the bag body 30 expands. When carbon dioxide gas leaks from the folding section 32, the first sealing member 10 is lifted and pressed in a direction toward the second sealing member 20. Since the sealing structure 90 is restrained by the outer box 60, the folding section 32 is firmly sandwiched between the covering surfaces 13 and 23. This prevents the folding section 32 from loosening and prevents gaps from forming between the folding section 32 and the covering surfaces 13 and 23. This prevents a large amount of gas (cold air) from leaking out of the bag body 30 from the sealing structure 90. In this embodiment, the insulating member 42 is disposed between the bottom surface of the outer box 60 and the bag body 30, so that the bottom surface of the outer box 60 can be prevented from expanding even if dry ice is stored as a cooling material.

Figure 5 shows an enlarged cross-sectional view of a portion of the folding section 32 and its vicinity. The first sealing member 10 has a first paper base material 10B and a first resin sheet 10A covering one side (top) of the first paper base material. The second sealing member 20 has a second paper base material 20B and a second resin sheet 20A covering one side (bottom) of the second paper base material 20B.

The first resin sheet 10A of the first sealing member 10 and the second resin sheet 20A of the second sealing member 20 are in contact with the folded portion 32. In this way, the folded portion 32 made of resin is in direct contact with the first resin sheet 10A and the second resin sheet 20A, thereby improving the adhesion between the first sealing member 10 and the second sealing member 20 and the folded portion 32 (bag body 30). In addition, it is possible to suppress the outflow of cold air (gas) from the folded portion 32. Therefore, the packaging container 100 (package body 200) has excellent cold insulation properties. In FIG. 5, gaps are drawn at both ends of the folded portion 32 to explain the folded portion 32, but in reality, these gaps may be crushed and adjacent materials may be in direct contact with each other vertically.

The first sealing member 10 may be a first resin sheet 10A laminated to a first paper base material 10B, or may be a first resin sheet 10A attached to a first paper base material 10B with adhesive or double-sided tape. The second sealing member 20 may be a second resin sheet 20A laminated to a second paper base material 20B, or may be a second resin sheet 20A attached to a second paper base material 20B with adhesive or double-sided tape. Examples of the first paper base material 10B and the second paper base material 20B include cardboard, coated cardboard, and other paper container boards, and boxes made of these. The box may be filled with a heat insulating material. Examples of heat insulating materials are as described above. The material and thickness of the first paper base material 10B and the second paper base material 20B may be the same or different.

Materials for the first resin sheet 10A and the second resin sheet 20A include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, and nylon. Of these, polyolefins are preferred from the viewpoint of reducing costs, and polyethylene is more preferred. The first resin sheet 10A and the second resin sheet 20A may also be biodegradable plastic films. Biodegradable plastic films are decomposed by microorganisms, and therefore can suppress, for example, marine pollution.

The thickness of the first resin sheet 10A and the second resin sheet 20A may be, for example, 1 to 100 μm, or 5 to 40 μm, from the viewpoint of achieving both strength and manufacturing costs. The first resin sheet 10A and the second resin sheet 20A may be a resin film. The material and thickness of the first resin sheet 10A and the second resin sheet 20A may be the same or different. The first resin sheet 10A and the second resin sheet 20A may each have a single-layer structure, or may be configured by laminating two or more layers of resin sheets. The first sealing member 10 and the second sealing member 20 may each be a laminate in which one or more paper base materials and one or more resin sheets are laminated.

The sealing structure 90 can seal the bag body 30 by tightly contacting the folding portion 32 with the covering surface 13 covered by the first resin sheet 10A and the covering surface 23 covered by the second resin sheet 20A. Therefore, the folding portion 32 does not need to have a welding portion or an adhesive portion. Therefore, the packaged item can be packed quickly and smoothly, and can be easily opened. Since there is no need to use a blade to open the bag body 30, it is also safe. By providing a sealing structure 90 in which the covering surfaces 13, 23 and the folding portion 32 are not bonded to each other, safety is improved and the packing and opening operations can be performed even more easily.

In this embodiment, only one side (the surface on the folding section 32 side) of the first paper base material 10B and the second paper base material 20B is covered with the first resin sheet 10A and the second resin sheet 20A, but this structure is not limited to this. For example, the entire surface of the first paper base material 10B and the second paper base material 20B may be covered with the first resin sheet 10A and the second resin sheet 20A.

Figure 6 shows the insulating member 41 that constitutes the side wall portion, the storage section 72 that is surrounded by the side wall portion, the packaged item 70 that is stored in the storage section 72, dry ice 75 that is placed on the packaged item 70, and the first sealing member 10 that forms a lid that covers the upper end side of the side wall portion. The side wall portion is formed by combining four insulating members 41 that contain insulating material. The insulating member 41 may be a box body filled with insulating material. The four insulating members 41 may be connected, or may be arranged along the inner wall of the outer box 60 to form the side wall portion. Examples of insulating materials and boxes are as described above.

The packaged item 70 is not limited to frozen foods and ice cream, but may be, for example, fresh foods or beverages. The packaging container 100 may not contain polystyrene foam and may be composed only of paper and resin sheets. Such packaging containers are lightweight and can be easily regenerated and recycled after use. This promotes recycling and allows for more effective use of resources.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, the packaging container 100 has a rectangular prism-like appearance, but may also be cylindrical. The insulating materials contained in the insulating members 41, 42 and the first sealing member 10 may be different from each other or may be the same. The outer box may be double- or triple-layered, in which case it may be constructed by combining cardboard and paperboard for folding cartons. The storage section may be divided into multiple sections along the vertical or horizontal direction.

In a modified example of the packaging container 100, a resin sheet may be arranged along the inner surface of the side wall portion. The resin sheet may be the same as the first resin sheet 10A and the second resin sheet 20A. In another modified example, the insulating member 41 constituting the side wall portion and the insulating member 42 for the bottom portion may be combined so as to be in direct contact with each other to form an inner box. In this case, the bag body may contain the inner box and the first sealing member 10, and the bag body 30 may be arranged so as to be interposed between the inner box and the inner surface of the outer box 60. In this case, a resin sheet may be arranged along the inner surface of the inner box. The resin sheet may be the same as the first resin sheet 10A and the second resin sheet 20A.

The contents of this disclosure will be explained in more detail with reference to examples and comparative examples, but this disclosure is not limited to the following examples.

Example 1
<Preparation of packaging container>
A packaging container as shown in Figs. 1 to 3 was produced. Defibrated material obtained by drying and defibrating pulp as a heat insulating material (manufactured by AIPA Corporation, obtained by setting the screen diameter of the defibrator to φ = 1 mm) was filled into a cardboard box (paper thickness: 1 mm) to produce heat insulating members that would become the side walls and bottom. The weight of the defibrated material filled into the heat insulating member 41 that would become the side walls was 190 g, and the weight of the defibrated material filled into the heat insulating member 42 that would become the bottom was 120 g. As the outer box 60, a cardboard box (length x width x height = 262 mm x 252 mm x 180 mm, thickness: 1 mm) was assembled using craft tape. As shown in Fig. 2, with the top surface of the cardboard box (outer box) open, the heat insulating member 42 that would become the bottom was placed on the bottom surface of the outer box 60. After that, the bag was placed so as to be in contact with the top surface of the heat insulating member 42 and the inner surface of the outer box. The bag used was a high-density polyethylene bag (HDPE, thickness: 13 μmm) having a perimeter approximately equal to that of the cardboard box used as the outer box.

As shown in FIG. 7(A), the side wall was formed using four insulating members 41 so that the bag was interposed between the inner surface of the outer box 60 and the insulating members 41. Next, as shown in FIG. 7(B), the upper end side of the side wall was sealed with the first sealing member 10 to make the storage section in which the packaged item was stored into a closed space. The first sealing member 10 was produced by storing an insulating material in a cardboard box (thickness: 1 mm) in which 80 g of the defibrated material was filled in a paper bag, and attaching a high-density polyethylene film (thickness: 12 μm) to one side (top surface) of the cardboard box with double-sided tape. The first sealing member 10 was placed on the side wall so that the high-density polyethylene film (thickness: 13 μm) was on the outside.

As shown in Figs. 8(A), (B) and 9(A), (B), the bag body 30 was folded so as to cover the first sealing member 10, forming a folded portion 32 on the first sealing member 10. The second sealing member 20 was placed over the folded portion 32 (Fig. 10(A)). The second sealing member 20 was made by attaching a high-density polyethylene film (thickness: 13 μm) to one side (lower surface) of a plate-shaped cardboard (thickness: 1 mm) with double-sided tape. The entire one side of the cardboard was covered with the film. The second sealing member 20 was placed over the folded portion 32 so that the surface covered by the film was in contact with the folded portion 32.

As shown in FIG. 10(B), the lid member 61 (flap) of the outer box was folded and fixed with craft tape to constrain the sealing structure. In this way, a packaging container with the appearance shown in FIG. 1 was obtained. As mentioned above, cardboard boxes were used for the insulating members that form the side walls and bottom, and the first sealing member, but in the photographs of FIG. 7 to FIG. 9, for ease of viewing, examples are shown in which boxes made of coated cardboard are used for these members instead of cardboard boxes.

<Creating packaging>
In the procedure for producing the above-mentioned packaging container, before placing the first sealing member 10 on the side wall, ice cream in a container was placed as the packaged item 70 in the storage section surrounded by the side wall, as shown in FIG. 6. The ice cream in the container was divided into an upper and lower tier, with four ice creams placed in each tier (total of eight ice creams). One of the four ice cream containers in each tier was selected, and a sensor (93 in FIG. 7(A)) of a thermometer (TR-71nw, product name, manufactured by T&D) was fixed inside the selected ice cream container. Dry ice (1050 g) was placed on the ice cream container in the upper tier as shown in FIG. 6. After that, the first sealing member 10 was placed on the storage section containing the ice cream and dry ice to make it a closed space, and the packaging container was produced in the same procedure as when producing the above-mentioned packaging container, to produce a package having the appearance shown in FIG. 1. The folded portion 32 of the bag was sealed by being sandwiched between the surface covered by the high-density polyethylene film of the first sealing member and the surface covered by the high-density polyethylene film of the second sealing member.

<Evaluation of workability during packaging work>
The ease of packaging was evaluated. If the packing work for the ice cream and dry ice could be carried out smoothly, it was evaluated as "passed", and if the packing work could not be carried out smoothly, it was evaluated as "failed". The results are shown in Table 1.

<Evaluation of cold retention>
After the folded portion was sealed, the temperature change over time in the upper and lower ice cream containers housed in the container was measured. The outside air temperature was kept constant at about 16° C. The measurement was continued for 24 hours.

Figure 11 (A) is a graph showing the measurement results. The lower curve shows the temperature inside the upper ice cream container, and the upper curve shows the temperature inside the lower ice cream container. Immediately after the measurement began, the temperature dropped due to the cooling effect of the dry ice, and reached its minimum temperature after 6 to 10 hours. The minimum temperatures inside the upper and lower ice cream containers, the temperatures after one day (24 hours), and the amount of dry ice remaining after one day were as shown in Table 1.

Example 2
As the first sealing member, a laminate was prepared by laminating a polypropylene film (thickness: ²⁰ μm) and a foamed polyethylene sheet (product name: Minafoam, thickness: 2 mm, manufactured by Sakai Chemical Industry Co., Ltd.) in this order on one side (upper surface) of a commercially available paperboard (coated board, 270 g/m2) from the coated board side to prepare a laminate. The polypropylene film was laminated and attached to one side of the coated board. The foamed polyethylene sheet was attached to the film using double-sided tape.

As the second sealing member, a laminate was prepared by laminating a polypropylene film (thickness: 20 μm) and a foamed polyethylene sheet (product name: Minafoam, thickness: ² mm, manufactured by Sakai Chemical Industry Co., Ltd.) in this order on one side (upper surface) of a commercially available paperboard (coated board, 270 g/m2) from the coated board side to prepare a laminate. The polypropylene film was laminated and attached to one side of the coated board. The foamed polyethylene sheet was attached to the film using double-sided tape.

A packaging container and a package were produced in the same manner as in Example 1, except that the above-mentioned first and second sealing members were used instead of the first and second sealing members 10 and 20 of Example 1, that a thermal insulation material in which defibrated material was enclosed in a paper bag was placed in a cardboard box (thickness: 1 mm) and sandwiched between the second sealing member and the top lid of the outer box, and that the initial weight of the dry ice was 1030 g. The folded portion of the bag was sandwiched and sealed between the expanded polyethylene sheet of the first sealing member and the expanded polyethylene sheet of the second sealing member. The cold retention of the package was evaluated in the same manner as in Example 1.

Figure 11 (B) is a graph showing the measurement results. The lower curve shows the temperature inside the upper ice cream container, and the upper curve shows the temperature inside the lower ice cream container. Immediately after the start of the measurement, the temperature dropped due to the cooling effect of the dry ice, and reached its minimum temperature after 3 to 9 hours. The minimum temperatures inside the upper and lower ice cream containers, as well as the temperature after one day (24 hours), the amount of dry ice remaining after one day, and the evaluation results of workability are shown in Table 1.

(Comparative Example 1)
A packaging container and a package were produced in the same manner as in Example 1, except that the first sealing member 10 and the second sealing member 20 were not used, and the weight of the defibrated material was slightly changed as follows. The weight of the defibrated material filled in the heat insulating member 41 that becomes the side wall was 200 g, the weight of the defibrated material filled in the heat insulating member 42 that becomes the bottom was 100 g, and the weight of the defibrated material filled in the paper bag used in the first sealing member 10 was 70 g. The folded part of the bag was sandwiched between a cardboard box (thickness: 1 mm) containing a heat insulating material in which the defibrated material was sealed in a paper bag, and a lid member (flap) of the outer box, and was apparently sealed. The cold insulation property of the package was evaluated in the same manner as in Example 1.

Figure 12 (A) is a graph showing the measurement results. The lower curve shows the temperature inside the upper ice cream container, and the upper curve shows the temperature inside the lower ice cream container. Immediately after the measurement began, the temperature dropped due to the cooling effect of the dry ice, and reached its minimum temperature after 6 to 9 hours. The minimum temperatures inside the upper and lower ice cream containers, as well as the temperature after one day (24 hours), the amount of dry ice remaining after one day, and the evaluation results of workability are shown in Table 1.

(Comparative Example 2)
As the first sealing member, a laminate was prepared by laminating a polypropylene film (thickness: 20 μm) on one side (upper surface) of a commercially available paperboard (coated cardboard, 270 g/m ² ). A packaging container and a package were produced in the same manner as in Example 2, except that this first sealing member was used, the polypropylene film of this first sealing member and the folded part of the bag body were attached with double-sided tape to seal the folded part, and the second sealing member was not used. The folded part of the bag body was sandwiched between the polypropylene film of the first sealing member and a cardboard box (paper thickness: 1 mm) containing a heat insulating material in which defibrated material was enclosed in a paper bag, and was apparently sealed by being attached with double-sided tape. The cold insulation property of the package was evaluated in the same manner as in Example 1.

Figure 12 (B) is a graph showing the measurement results. The lower curve shows the temperature inside the upper ice cream container, and the upper curve shows the temperature inside the lower ice cream container. Immediately after the start of the measurement, the temperature dropped due to the cooling effect of the dry ice, and reached its minimum temperature after 5 to 10 hours. The minimum temperatures inside the upper and lower ice cream containers, as well as the temperature after one day (24 hours), the amount of dry ice remaining after one day, and the evaluation results of workability are shown in Table 1.

Example 3
A packaging container and a package were produced in the same manner as in Example 1, except that a commercially available kitchen paper (manufactured by Oji Nepia Co., Ltd., product name: Nepia Super Absorbent Kitchen Towel) was used as the heat insulating material, and the initial weight of the dry ice was 1020 g. The number of kitchen paper sheets filled in the heat insulating member 41 that becomes the side wall part was 24 sheets each (total of 24 sheets x 4 = 96 sheets, thickness of each cardboard box: 20 mm), the number of kitchen paper sheets filled in the heat insulating member 42 that becomes the bottom part was 39 sheets (thickness of cardboard box: 25 mm), and the number of kitchen paper sheets filled in the cardboard box (paper thickness: 1 mm, box thickness: 20 mm) in the first sealing member 10 was 23 sheets.

Figure 13 (A) is a graph showing the measurement results. The lower curve shows the temperature inside the upper ice cream container, and the upper curve shows the temperature inside the lower ice cream container. Immediately after the measurement began, the temperature dropped due to the cooling effect of the dry ice, and reached its minimum temperature after 4 to 7 hours. The minimum temperatures inside the upper and lower ice cream containers, as well as the temperature after one day (24 hours), the amount of dry ice remaining after one day, and the evaluation results of workability are shown in Table 2.

Example 4
A packaging container and a package were produced in the same manner as in Example 1, except that a commercially available kitchen paper (manufactured by Oji Nepia Co., Ltd., product name: Nepia Super Absorbent Kitchen Towel) was used as the heat insulating material, and the initial weight of the dry ice was 1060 g. The number of kitchen paper sheets filled in the heat insulating member 42 that becomes the side wall part was 40 sheets each (total of 40 sheets x 4 = 160 sheets, thickness of each cardboard box: 25 mm), the number of kitchen paper sheets filled in the heat insulating member 41 that becomes the bottom part was 40 sheets (thickness of cardboard box: 25 mm), and the number of kitchen paper sheets filled in the cardboard box (paper thickness: 1 mm, box thickness: 25 mm) in the first sealing member 10 was 40 sheets.

Figure 13 (B) is a graph showing the measurement results. The lower curve shows the temperature inside the upper ice cream container, and the upper curve shows the temperature inside the lower ice cream container. Immediately after the start of the measurement, the temperature dropped due to the cooling effect of the dry ice, and reached its minimum temperature after 7 to 10 hours. The minimum temperatures inside the upper and lower ice cream containers, as well as the temperature after one day (24 hours), the amount of dry ice remaining after one day, and the evaluation results of workability are shown in Table 2.

(Comparative Example 3)
As shown in Figures 8(A), 8(B) and 9(A), 8(B), instead of folding the bag body 30 to cover the first sealing member 10, the upper end of the bag body 30 was tied with a string and sealed. However, immediately after tying and sealing, the bag body 30 expanded due to the sublimation of the dry ice, and it was not possible to cover it with the second sealing member. At this point, the packaging work was stopped. For this reason, the evaluation result of the workability was "failed."

As shown in Table 1, it was confirmed that the packages (packaging containers) of Examples 1 to 4 had excellent cold insulation. In addition, in Examples 1 to 4, the folded part of the bag was sandwiched between the covering surface of the first resin sheet of the first sealing member and the covering surface of the second resin sheet of the second sealing member, and the sealing structure formed by sandwiching the folded part of the bag was restrained by an outer box. For this reason, the packaging work could be performed smoothly. In Examples 1 to 4, the sealing property in the sealing structure was well maintained, which is thought to be the reason why excellent cold insulation was obtained. In particular, Examples 3 and 4, which used kitchen paper, had even better cold insulation. This is thought to be due to the excellent cold insulation of kitchen paper. On the other hand, in Comparative Example 1, the packaging work could be performed smoothly, but the cold insulation was inferior to Examples 1 and 2. The reasons for this are thought to be that the amount of leakage of cold air ( _CO2 gas) from the folded part increased because the first sealing member and the second sealing member were not used, and that sufficient insulation was not achieved. For this reason, the temperature of the ice cream in the upper row in particular was high.

In Comparative Example 2, the minimum temperature was reached immediately at the beginning of packaging, but the temperature rose rapidly along the way. The cause of this is thought to be that the folded part of the bag was initially sealed with double-sided tape (which caused the outer box to expand somewhat), but the double-sided tape peeled off due to deformation caused by the increase in internal pressure, resulting in a large amount of leakage of cold air ( _CO2 gas). In Comparative Example 3, the bag expanded immediately after tying it, making it impossible to continue the packaging work. From these results, it was confirmed that the sealing structure using the folded part in Examples 1 to 4 can close the lid member of the outer box and seal the bag almost simultaneously, so that the work can be carried out smoothly even with a cooling material that generates gas, such as dry ice, and the packaging work can be simplified.

10...first sealing member, 10A...first resin sheet, 10B...first paper base material, 13, 23...covering surface, 20...second sealing member, 20A...second resin sheet, 20B...second paper base material, 24...opening, 30...bag body, 32...folding portion, 41, 42...insulating member, 60...outer box, 64...side wall, 61...lid member, 66...tape, 70...item to be packaged, 72...container, 75...dry ice, 90...sealing structure, 100...packaging container, 200...packaging body.

Claims (10)

a first sealing member having a first paper substrate and a first resin sheet covering at least a portion of the surface of the first paper substrate;
a second sealing member having a second paper substrate and a second resin sheet covering at least a portion of the surface of the second paper substrate;
The package includes an object to be packed, a heat insulating member surrounding the object, and a resin bag that contains the first sealing member,
A packaging container for cold storage, having a sealing structure in which a folded portion of the bag body formed by folding the bag body to seal it is sandwiched between a covered surface of the first resin sheet of the first sealing member and a covered surface of the second resin sheet of the second sealing member. The cold storage packaging container according to claim 1, further comprising an outer box that houses the bag body, and the sealing structure is constrained by the outer box. The cold storage packaging container according to claim 1, wherein the first sealing member is a lid that is placed over the upper end of the side wall portion made of the insulating member, and forms a closed space together with the side wall portion to accommodate the packaged item. The cold storage packaging container according to claim 2, wherein the second sealing member is a plate-shaped member disposed between the lid member that closes the outer box and the folding portion. The cold storage packaging container according to claim 1, in which dry ice is stored together with the item to be packed in the storage section surrounded by the insulating material. The cold storage packaging container according to claim 1, wherein the heat insulating material contains at least one of kitchen paper and molded pulp. The cold storage packaging container according to claim 2, wherein the insulating member and the outer box are made of paper. The first resin sheet and the second resin sheet are made of polyethylene or polypropylene,
The cold storage packaging container according to claim 1 , wherein the bag body is made of high-density polyethylene. The packaging container according to any one of claims 1 to 8,
A package comprising an item to be packed and dry ice contained in the packaging container. The package according to claim 9 , wherein the packaged items include at least one of frozen food and frozen desserts.

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