JP2024117035A - Packaging method and packaging container - Google Patents

Abstract

To contribute to improving commercial value by preventing the displacement of the contents, such as a food product like an oyster in a half body state, in which the hardness and shape of the upper and lower sides are different, while preserving desired freshness.SOLUTION: A film 2 is covered in a vacuum region of 5000-45000 Pa from above the contents contained in a container body 1 of a packaging container. The film is made of an olefin resin, and preferably has a thickness of 60 μm or more. The container body comprises a bottom part 11 for placing the contents and a side part 12 continuously formed above from the peripheral end edge of the bottom part so as to be higher than the thickness of the contents. Also preferably, the film is brought into tight contact with the inner surface of the side part while avoiding tight contact with the bottom part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a packaging method and a packaging container that prevent the contents, such as food with different hardness depending on the part, from shifting out of position.

Conventionally, foods such as fresh produce, for example meat and seafood sold in supermarkets and convenience stores, are placed or stored in a container body of a specific shape, and then the opening of the container body is closed with a lid of a specific shape, the air inside the container body is removed and filled with nitrogen, carbon dioxide, or a mixture of these, and the opening is sealed with a top seal, or a heated skin pack film is attached under a vacuum to the inner surface of the container body together with the food to seal the food.

For example, Patent Document 1 discloses a packaging container that includes a box-shaped container body with multiple storage chambers formed by partition walls that are approximately half the height of the side walls of the container body and that contain raw shucked oysters with both shells removed, an inner lid placed to cover the storage chambers, and a sealing sheet that seals the opening of the container body, with a space between the inner lid and the sealing sheet, and with which deliciously cooked steamed oysters can be obtained in a microwave oven.

Patent Document 2 also discloses a tray that has a number of storage recesses formed by the storage wall for storing oysters with shells (raw oysters contained in both shells of a bivalve), with the storage recesses having through holes, which can prevent the oysters from moving unevenly even if vibrations occur during transportation, drain moisture generated by the oysters to the outside of the storage recesses, and allow cold air from ice packs placed above the tray to flow downward.

JP 2019-85162 A Utility Model Registration No. 3224346

If the oysters are packaged without the shells removed and in their shells as in Patent Document 1, there is a risk that the freshness of the oysters will decrease or that they will look less fresh. Furthermore, if they are packaged with their shells on as in Patent Document 2, not only is it time-consuming to select oysters with shells of similar shapes and sizes, but there is also a risk that oysters of uneven sizes will be selected by mistake. However, when packaging raw oysters, there is no choice but to choose either shucked oysters as in Patent Document 1 or with the shells on as in Patent Document 2.

Generally, when raw oysters are eaten, the upper shell, which acts as a lid, is removed and they are served in half (raw oysters in a half shell with only the lower shell remaining, i.e., a bivalve with one shell removed). This avoids problems such as those described in Patent Documents 1 and 2 above, and is expected to improve commercial value. Similarly, the inventors thought that if the specifications are suitable for both the shell, which has a hard, sharp part on the bottom, and the meat, which has a soft, smooth part on the top, then even if the oysters are packaged in half, the commercial value can be expected to improve.

The above-mentioned skin pack film packaging has been adopted for foods that are not easily crushed or deformed by the film that adheres tightly in a vacuum state. On the other hand, for foods that only need to maintain freshness for a desired period of time, even if their expiration date is shorter than that of the above-mentioned foods, the degree of the vacuum state may be reduced, in other words, the foods may be packaged in a state where the degree of pressure applied by the skin pack film is reduced, and the inventors have concluded that such a state corresponds to the above-mentioned specifications.

The object of the present invention is to provide a packaging method and packaging container that contributes to improving the commercial value of food or other contents by preventing them from shifting position when the upper and lower sides of the contents have different hardness or shapes, such as half-shelled oysters (raw oysters with one shell removed), and by maintaining the desired freshness.

That is, the packaging method of the present invention is characterized by including the steps of preparing a packaging container having a bottom on which the contents are placed and a side wall portion formed continuously upward from the peripheral edge of the bottom, placing the contents in the packaging container, and covering the packaging container on which the contents are placed with a top film in a vacuum region of 5,000 to 45,000 Pa and adhering the top film to the upper end of the side wall portion.

The top film is preferably made of an olefin resin and has a thickness of 60 μm or more.

It is desirable to have the film adhere to the inner surface of the side wall, rather than to the bottom.

The container body of the packaging container of the present invention is used in the above packaging method, and is characterized in that it has a bottom on which the contents are placed and a side portion formed continuously upward from the peripheral edge of the bottom, the side portion having a height of 20 mm or more and an angle of 40 to 90 degrees with respect to the bottom.

The container body of another packaging container of the present invention is used in the above packaging method, and is characterized by having a bottom on which the contents are placed, a side portion formed continuously upward from the peripheral edge of the bottom, a first protrusion formed upward from the bottom and against which the contents are leaned, and a pair of second protrusions formed continuously upward from the upper end of the first protrusion and positioned on both sides of the contents.

The upper container body further includes a third protrusion formed in a straight line from the bottom upward, continuing from one side of the first protrusion and the lower end of the first protrusion, and a content placement section composed of the first protrusion, the second protrusion, and the third protrusion, and the size of the content placed on the placement section is determined by the longitudinal width of the first protrusion and the longitudinal width of the third protrusion.

The present invention is expected to contribute to improving product value by preventing food or other contents with different hardness or shapes between the top and bottom, such as half-shelled oysters (raw oysters with one shell removed), from shifting position and maintaining the desired freshness, thereby preventing cargo from falling apart during delivery and increasing the freedom of product display.

FIG. 1 is a perspective view of a packaging container according to one embodiment of the present invention. 2A and 2B are partially enlarged end views of the packaging container. FIG. 2 is a partially enlarged conceptual perspective view of a state in which a packaging method in one embodiment of the present invention is carried out using the packaging container. 1A is a plan view and FIG. 1B is a front view of the packaging container. 1A is a partially enlarged perspective conceptual diagram of the packaging container, and FIG. 1B is a partially enlarged cross-sectional view of the packaging container, and FIG.

The packaging method (hereinafter also referred to as "this packaging method") and packaging container (hereinafter also referred to as "this packaging container") according to one embodiment of the present invention will be described below with reference to Figures 1 to 5. In these figures, where there are multiple identical parts, only one part is numbered. For ease of explanation, certain parts and their leading lines are shown with hidden lines (broken lines) or imaginary lines (two-dot chain lines), and cross sections are shown with hatching in some parts. In the explanation, terms indicating directions such as up, down, side, vertical, horizontal, etc. are basically based on the state in which the packaging container is installed in the normal orientation, and if other orientations are used as the basis, they will be explained appropriately.

<Basic configuration of the packaging container used in the packaging method>
As shown in Fig. 1, this packaging container is used to package food F such as seafood, meat, and fruit to be sold in a retail store such as a supermarket, and includes a container body 1 and a top film 2 attached to cover the opening of the container body 1. The container body 1 is substantially rectangular in plan view, but may be rectangular, circular, or elliptical, and may be of any size that can be placed on a display shelf in a retail store, with no limitations on dimensions such as length, width, and height. This packaging container may refer to only the container body 1, and in this case the top film 2 corresponds to the lid of this packaging container.

<Overview of container body 1>
The container body 1 preferably includes a bottom 11 on which the food F is placed, a storage section formed of a side wall 12 that rises while expanding upward from the peripheral edge of the bottom 11, a flange 13 that extends outward from the upper edge of the side wall 12, which is also the upper edge of the storage section, and a placement section 1a corresponding to the position where each food F is placed. The upper edge of the side wall 12 corresponds to the opening of the container body 1. The bottom 11 has the same shape as the container body 1 in a plan view, but may have a different shape. The side wall 12 is flat, but may have a curved shape with the upper side expanding further outward.

Any food F that is hard on the bottom side that contacts the container body 1 and soft on the top side that contacts the top film 2 is applicable, but examples of such food F include shellfish such as raw oysters with the shell on the bottom and the meat on the top, crustaceans such as crabs with the shell on the bottom and the meat on the top, meat with bones on the bottom and meat on the top, and fruits (including some herbaceous plants) with thick skin (corresponding to sebum) on the bottom and flesh (edible part) on the top. When placed on the placement part 1a, food F is acceptable as long as it does not exceed the top end of the side wall part 12, is equal to the top end, or is slightly thicker than the top end. If the thickness does not exceed the top end, it is sufficient for the food F to be at least half the height of the side wall part 12.

2(A) is an enlarged end view of a part of the side wall portion 12 and the flange portion 13. As shown in FIG. 2(A), the side wall portion 12 has a flat unnumbered side wall flat portion and a curved (may be flat) side wall upper end portion 12a formed continuously upward from the upper end of the side wall flat portion. The flange portion 13 has an unnumbered flange flat portion formed continuously outward from the side wall uppermost end portion 12b, which is the uppermost end of the side wall upper end portion 12a, and a flat surface and circumferentially flat flange side portion formed continuously outward and downward from the flange flat portion, and a flange tip portion formed continuously outward from the flange side portion. The flange portion 13 may have a flange curved portion curved upward instead of the flange flat portion. FIG. 2(B) is an enlarged end view of FIG. 2(A) excluding the flange portion 13, and the container body 1 may not have the flange portion 13 formed.

The top film 2 may be adhered only to the flange portion 13, or to the flange portion 13 and the sidewall upper end portion 12a, or if the flange portion 13 is not formed, to only the sidewall upper end portion 12a. The flange portion 13 to which the top film 2 is in close contact may be only the flange flat portion, or the flange flat portion and the flange side portion. The sidewall upper end portion 12 to which the top film is in close contact may be at least 10 mm from the sidewall uppermost end portion 12b, and may be at least 20 mm, 25 mm, or 30 mm.

<Material, manufacturing method, dimensions, etc. of container body 1>
The container body 1 is molded using a synthetic resin sheet as a base material. The synthetic resin sheet may be made of, for example, an olefin resin such as polyethylene (PE) or polypropylene (PP), polystyrene paper (PSP) made of a polystyrene resin, high impact polystyrene (HIPS) in which an elastic material such as a butadiene copolymer is blended with GP polystyrene to improve impact resistance, or a polyester resin such as polyethylene terephthalate (PET), and may be composed of a single layer or multiple layers, may be colored or colorless transparent, or may be opaque, and may be formed of a material having heat resistance. The synthetic resin sheet is formed into a desired shape of the container body by a thermoforming method such as vacuum molding, hot plate pressure molding, vacuum pressure molding, double-sided vacuum molding, etc. The front and/or back surface of the synthetic resin sheet may be laminated with a synthetic resin film. The synthetic resin film may be composed of a single layer or multiple layers having heat resistance, oil resistance, lamination suitability with a printed layer, gas barrier property, etc., and may include a printed layer when the surface of the synthetic resin sheet is laminated.

The synthetic resin sheet may be made of foamed or non-foamed resin. There is no particular limit to the thickness of the synthetic resin sheet, but in the case of non-foamed resin, the thickness is 0.18 to 1 mm, preferably 0.3 to 0.8 mm, and more preferably 0.35 to 0.6 mm. In the case of low-foamed resin with an expansion ratio of 1.5 to 3 times, the thickness is 0.5 to 3 mm, preferably 1 to 2 mm. In the case of high-foamed resin with an expansion ratio of 5 to 15 times, the thickness is 1.5 to 5 mm, preferably 1.8 to 4 mm, and more preferably 2.0 to 3.5 mm. The expansion ratio is calculated by measuring the specific volume (unit: cc/g) of the foamed composition before and after foaming (foamed sheet) and calculating the specific volume after foaming/specific volume before foaming.

In the case of foamed resin, the basis weight (mass per unit area) may be 120 to 220 g/ ^m2 , but as the weight increases, the amount of resin increases, which is preferable because it is relatively easier to obtain the desired strength, but the material cost increases accordingly, so it is necessary to select a weight that takes this balance into consideration. When the top film 2 is attached to the inside surface of the container body 1, the container body 1 is pulled by the top film 2 that had been stretched up until then, so a relatively high strength is required, and therefore the basis weight is preferably 130 to 220 g/ ^m2 , more preferably 140 to 200 g/ ^m2 , and even more preferably 150 to 200 g/ ^m2 .

<Overview of placement unit 1a>
There are six placement sections 1a in the storage section, but there may be one or more depending on the width of the bottom 11 and/or the size of the food F, and the area may be any. The placement section 1a is rectangular in shape having a short side and a long side in a plan view, but may be square, circular, or elliptical. The placement section 1a is formed by each of the parts raised from the bottom 11, and the above parts may be one or more, and may be arranged to surround the entire circumference of the placed food F or to surround a part such as half of it, and may be a flat part that is not a raised part or a part recessed downward from the bottom 11. The placement section 1a may be arranged so that the long side is inclined at any angle based on the side wall section 12 located on the front side in FIG. 1A, for example, it may be inclined at 30° to 60° with respect to the side wall section 12, and may be arranged so that the long side is parallel or perpendicular.

<An example of this packaging method>
First, the container body 1 is prepared (hereinafter also referred to as the "container preparation step"). Next, the food F is placed on the placement portion 1a (hereinafter also referred to as the "food placement step"). Next, while sucking air so that the inside of the container body 1 becomes a vacuum region of 5000 to 45000 Pa, the top film 2 is placed and adhered to cover the opening of the container body 1 and hangs over the flange portion 13 (or the upper end portion 12a of the side wall if the flange portion 13 is not present) (hereinafter also referred to as the "top film attachment step"). According to this step, the top film 2 presses the food F against the container body 1 to a degree that does not crush it, so that the food F is expected to be less likely to shift position. After the top film attachment step, the top film 2 is cut.

Here, in the above-mentioned top film attachment process, it is preferable that the top film is heated and softened. The heating temperature may be, for example, 90 to 250°C, or may be 140 to 220°C, 160 to 200°C, or 170 to 190°C.

The vacuum region in the top film attachment process refers to the pressure at which so-called vacuum packing of food is produced, and should be lower than the 1 to 10 ³ Pa used to produce conventional vacuum packing of food, and is preferably 5,000 to 45,000 Pa, more preferably 7,500 to 38,000 Pa, even more preferably 10,000 to 30,000 Pa, and even more preferably 10,000 to 25,000 Pa. If the pressure is lower than 5,000 Pa, the food F will be crushed by the top film 2, and if the pressure is higher than 45,000 Pa, the top film 2 may not be able to hold down the food F, causing it to shift position.

<Top film 2 material, dimensions, etc.>
The top film 2 is a so-called skin pack film, and although there are no limitations on the material or layer structure from which it is formed, it is preferably made of an olefin-based resin which is easy to stretch and difficult to tear, and its thickness is 60 μm or more, preferably 70 to 400 μm, more preferably 80 to 300 μm, and even more preferably 100 to 200 μm. Even if it is made of an olefin-based resin, if it is thinner than 60 μm it will be easy to tear, and if it is thicker than 400 μm it will be difficult to stretch and there is a risk that the food F will be crushed.

Regardless of the type of top film 2, it is preferable that it be transparent, because the contents can be easily seen through the top film.

The top film 2 may be a multi-layer film consisting of multiple layers, and may have an inner layer that contacts the inner surface of the container body 1 and the surface of the food F, and an outer layer laminated to the inner layer. The outer layer may have shape retention properties that allow it to stretch three-dimensionally along the shape of the inner surface of the container body 1 and/or the surface of the food F when heated and softened, and to retain that shape when cooled. The top film 2 may have a functional layer such as a gas barrier layer or a reinforcing layer as an intermediate layer between the inner layer and the outer layer.

<Details of the top film attachment process>
As shown in Fig. 3, in the top film attachment process, the top film 2 is heated to melt and soften, and then the top film 2 is welded and bonded to the flange portion 13 (or the upper end portion 12a of the side wall if there is no flange portion 13). At this time, the top film 2 is not in close contact with the bottom 11 of the container body 1, and is in close contact with the inner surface of the side wall portion 12 without being bonded. This process makes it difficult for the tension of the top film 2 to loosen, and the top film 2 can pressurize the soft upper side of the food F downward only within a predetermined range, so that even a thick food F including the hard lower side is unlikely to shift out of position. The vertical width of the top film 2 in close contact with the inner surface of the side wall portion 12 is approximately equal to the height from the upper end of the food F to the upper end of the side wall portion 12.

<Details of Container Body 1>
4A and 4B, the height h1 of the side wall 12, which corresponds to the height from the surface of the bottom 11 to the top end of the side wall 12, is preferably 20 mm or more, and may be 30 mm or more, or 40 mm or more. There is no particular limit to the upper limit of the height h1 of the side wall 12, but it may be 150 mm or 100 mm. The angle d with respect to the bottom 11 is 40 to 90°, preferably 50 to 85°, more preferably 60 to 80°, and even more preferably 70 to 80°. If the height h1 is less than 20 mm, the amount of food F that can be accommodated is limited, and if the angle d is less than 40°, the side wall 12 is too reclined and it is difficult to satisfy the condition of the height h1, and if it is more than 90°, the side wall 12 is too upright and it is difficult to attach the top film 2.

<Details of Mounting Unit 1a>
5(A) and (B), the placement portion 1a includes a first protrusion 14 formed upward from the bottom 11 on which the food F is leaned, and a pair of second protrusions 15, 15 formed continuously upward from the upper end of the first protrusion 14 and positioned on both sides of the food F. In other words, the first protrusion 14 is a part that protrudes in a mountain shape from the bottom 11, and the second protrusions 15, 15 are parts that protrude at the same height or different heights from both ends of the upper end of the first protrusion 14. With this configuration, the food F is leaned diagonally against the first protrusion 14, and the second protrusions 15, 15 support both sides of the food F, so that it is expected to be easy to serve food F that is long, thin, complex, and easily displaced, such as an oyster shell.

As shown in FIG. 5B, the ratio of the height h2 from the surface of the bottom 11 to the top end of the first protrusion 14 to the height h3 from the top end to the apex of the second protrusion 15 is about 4:1, but may be about 3:1 or 2:1 depending on the thickness and shape of the food F, and the height h3 may be higher than 4:1 or lower than 2:1. The height h4 of the apex of the second protrusion 15 is about one-fifth of the height h1 of the side wall 12 shown in FIG. 4B, but may be about one-tenth or one-half depending on the thickness of the food F, or may be lower than one-tenth or higher than one-half. The second protrusions 15, 15 may be both ends of the upper end of the first protrusion 14 that is curved downward.

As shown in Figures 5 (A) and (C), the placement portion 1a further includes a third protrusion 16 that is continuous with one of the side portions 14a and the lower end portion 14b of the first protrusion 14, is linear, and is formed upward from the bottom portion 11. In other words, the third protrusion 16 is a portion that protrudes upward from the bottom portion 11 in a mountain-like shape. With this configuration, the third protrusion 16 acts as a wall for the food F that is piled up against the first protrusion 14 and the second protrusions 15, 15, so that the food F is less likely to slide sideways.

5(B) and (C), the height h5 of the third protrusion 16 is lower than the height h2 to the top end of the first protrusion 14 and the height h4 of the apex of the second protrusion 15, and may be about one-ninth or one-fifth of each depending on the thickness of the food F, or may be lower than one-ninth or higher than one-fifth, or may be equal to the height h2 to the top end of the first protrusion 14 or the height h4 of the apex of the second protrusion 15. The length W1 of the straight part of the third protrusion 16 is about three times the length W2 of the straight part of the first protrusion 14, but may be about four times or twice as long depending on the length of the food F, or may be more than four times or less than two times as long, or may be equal to the length W2 of the straight part of the first protrusion 14. The third protrusion 16 may not be continuous with the first protrusion 14, but may be formed at a predetermined interval.

As shown in FIG. 5(A), the third protrusion 16 is formed continuous with one side 14a and the lower end 14b of the first protrusion 14 that constitutes another mounting portion 1b located in front of the mounting portion 1a. With this configuration, mounting portions 1a and 1b do not interfere with each other, so that the area for placing food F can be efficiently secured.

The packaging method shown in this embodiment and the packaging container used in this packaging method are not limited to the above, and include any order of steps, relationships between steps, positions, shapes, and dimensions of parts, and relationships between parts, as long as the same effect can be obtained.

As shown in FIG. 1, food F is handled as a product when it is contained in container body 1 and wrapped in top film 2, but when the product is sold at a retail store or the like in a box with a film-like surface that is entirely or partially transparent, it may be placed horizontally on a display shelf with bottom 11 facing downwards, or vertically with side wall 12 facing downwards. In the case of vertical placement, improved visibility of food F can be expected if the first protrusion 1 is oriented downwards.

REFERENCE SIGNS LIST 1 container body 1a placement portion 11 bottom portion 12 side portion 13 flange portion 14 first projection portion, 14a first projection side portion, 14b first projection lower end portion 15 second projection portion 16 third projection portion 2 film

Claims (6)

A step of preparing a packaging container having a bottom portion on which contents are placed and a side wall portion formed continuously upward from a peripheral edge of the bottom portion;
placing contents in the packaging container;
and covering the packaging container with the contents placed thereon with a top film in a vacuum region of 5,000 to 45,000 Pa, and adhering the top film to an upper end of the side wall portion. 2. The packaging method according to claim 1, wherein the top film is made of an olefin-based resin and has a thickness of 60 μm or more. The packaging method according to claim 1 , wherein the top film is not in close contact with the bottom portion, but is in close contact with the inner surface of the side wall portion. A container body of a packaging container used in the packaging method according to claim 1,
A bottom portion on which contents are placed;
a side portion formed continuously upward from the peripheral edge of the bottom portion;
A packaging container, characterized in that the side has a height of 20 mm or more and is at an angle of 40 to 90 degrees to the bottom. A container body of a packaging container used in the packaging method according to claim 1,
A bottom portion on which contents are placed;
a side portion formed continuously upward from the peripheral edge of the bottom portion;
A first protrusion formed upward from the bottom portion, on which the contents are supported;
A packaging container comprising: a pair of second protrusions formed continuously upward from an upper end of the first protrusion and positioned on both sides of the contents. a third protrusion formed linearly and upward from the bottom, continuous with one of the sides and the lower end of the first protrusion;
Further comprising a content placement section configured with a first protrusion, a second protrusion, and a third protrusion,
The packaging container according to claim 5, wherein a size of the content placed on the placement portion is determined by a longitudinal width of the first protruding portion and a longitudinal width of the third protruding portion.

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