Delicate-fruit packaging

Abstract

This delicate-fruit packaging includes: a container having a flat, substantially rectangular container bottom and four container side walls that extend upward from the entire peripheral edge of the container bottom to form an open-top container; a plurality of delicate fruits stored in either a single flat layer or two vertical layers in a storage space surrounded by the container side walls; and a heat-shrink film for wrapping so as to cover the plurality of delicate fruits and the entire periphery of the container. Or, this delicate-fruit packaging includes: a container having a container bottom where a delicate-fruit storage section is formed or a container having a storage space in which a buffer tray where a delicate-fruit storage section is formed is arranged; a plurality of delicate fruits stored in the delicate-fruit storage section; and a heat-shrink film for wrapping so as to cover the plurality of delicate fruits and the entire periphery of the container. This delicate-fruit packaging satisfies a specific condition.

Description

Soft fruit packaging

[0001] This invention relates to a soft fruit packaging material. More specifically, it relates to a soft fruit packaging material that prevents damage to soft fruit due to vibration during transport.

[0002] To maintain the quality of harvested fruit and deliver it to market, it is necessary to protect the fruit from shocks during transportation. For example, delicate fruits such as strawberries, which have thin skins and soft flesh, are easily damaged by vibrations during transport, and therefore require special measures.

[0003] Due to the circumstances described above, a fruit storage tray has been proposed in which a thin thermoplastic synthetic resin sheet is formed with fruit storage recesses for individually storing relatively fragile fruits such as strawberries (Patent Document 1). In addition, a packaging body comprising a container X including an inner container for individually storing fruits has been proposed (Patent Document 2).

[0004] Japanese Patent Publication No. 2011-102152 Japanese Patent Publication No. 2021-75310

[0005] However, the fruit storage tray proposed in Patent Document 1 and the packaging body proposed in Patent Document 2 have many components, and the components are complex, which has disadvantages in terms of cost and loading efficiency when it comes to manufacturing these components.

[0006] The present invention aims to provide a new soft fruit packaging material that prevents damage to soft fruits due to vibration during transportation.

[0007] As a result of diligent research to solve the above problems, the inventors have found that a package in which multiple soft fruits are stored in the storage space of a container in a single-layer or two-layer arrangement that satisfies specific conditions, and which is wrapped in heat-shrinkable film to cover the entire perimeter of the container and the multiple soft fruits, can prevent damage to the soft fruits due to vibration. Furthermore, the inventors have found that a package comprising a container having a container bottom formed with a soft fruit storage section, or a container in which a cushioning tray with a soft fruit storage section is arranged in the storage space, and which is wrapped in heat-shrinkable film to cover the entire perimeter of the container and satisfies specific conditions, can prevent damage to the soft fruits due to vibration, and have completed the present invention.

[0008] In other words, the present invention provides the following [1] to

[17] . [1] A soft fruit package comprising a container having a flat, substantially rectangular container bottom and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a plurality of soft fruits stored in a single layer in a storage space surrounded by the container side walls, and a heat shrinkable film that covers the plurality of soft fruits and the entire periphery of the container, wherein the plurality of soft fruits satisfy the following conditions: Condition (1): The plurality of soft fruits are in contact with at least one of each other. Condition (2): At least one soft fruit is in contact with each of the four container side walls forming the container. Condition (3): The plurality of soft fruits are in contact with the heat shrinkable film. Condition (4): The plurality of soft fruits are in contact with the container bottom. [2] A soft fruit package comprising a container having a flat, substantially rectangular container bottom and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a plurality of soft fruits stored in two layers, upper and lower, in a storage space surrounded by the container side walls, and a heat shrinkable film that covers the plurality of soft fruits and the entire periphery of the container, wherein the plurality of soft fruits satisfy the following conditions: Condition (1): The plurality of soft fruits are in contact with at least one of each other. Condition (2): At least one soft fruit is in contact with each of the four container side walls forming the container. Condition (3'): Of the plurality of soft fruits, the soft fruits stored in the upper layer are in contact with the heat shrinkable film, and the soft fruits stored in the lower layer are in contact with the soft fruits stored in the upper layer. Condition (4'): Of the plurality of soft fruits, the soft fruits stored in the lower layer are in contact with the container bottom. [3] The soft fruit packaging according to [1] or [2], wherein the soft fruit is a strawberry. [4] The soft fruit packaging according to [1] or [2], wherein the heat shrinkable film is provided with a number of small through-holes, the small through-holes being concentrated at the top of the open container. [5] The soft fruit packaging according to [1] or [2], wherein the heat shrinkable film comprises a layer containing an antifungal agent and / or an antifogging agent.[6] The soft fruit packaging according to [1] or [2], wherein the heat shrinkable film has a heat shrinkage rate of 58% to 67% in both the MD (longitudinal direction) and TD (width direction) at 120°C, a heat shrinkage force of 0.25 N / cm or less in the MD at 120°C, a heat shrinkage force of 0.22 N / cm or less in the TD at 120°C, a tensile modulus of elasticity of 0.25 GPa to 0.29 GPa in the MD, and a tensile modulus of elasticity of 0.25 GPa to 0.27 GPa in the TD. [7] The soft fruit packaging according to [1] or [2], wherein the heat shrinkable film comprises a plant-derived polyethylene resin. [8] The soft fruit packaging described in [1] or [2], wherein the electrical conductivity of the aqueous solution in which the soft fruit was immersed after a vibration test, measured by the evaluation method below, is reduced by 20% or more compared to the soft fruit packaging described in [1] or [2], in which the soft fruit packaging is packaged with a non-heat-shrinkable film instead of a heat-shrinkable film so as to cover at least the upper part of the opening of the container. [Electrical conductivity of aqueous solution in which soft fruit was immersed after a vibration test] (1) Vibration test A sinusoidal uniform sweep vibration test is performed for 30 minutes on a container containing one or more soft fruit packagings using a vibration test apparatus under the following conditions. (Conditions for vibration test) Lower frequency limit: 10 Hz, upper frequency limit: 40 Hz, sweep time: 10 minutes, number of sweeps: 3, vibration direction: simultaneous of three axes: X axis (horizontal), Y axis (horizontal), Z axis (vertical), gravitational acceleration: 0 G to 3 G (m / s). ２) (Dependent on frequency). (2) Electrical conductivity measurement After the vibration test, the multiple soft fruits removed from the container are placed in six times the total weight of the multiple soft fruits in pure water (electrical conductivity 1.0 μS / cm), the aqueous solution in which the soft fruits are immersed is stirred for 30 minutes, and the electrical conductivity measured using an electrical conductivity meter for the aqueous solution is taken as the electrical conductivity of the aqueous solution in which the soft fruits were immersed after the vibration test. [9] A soft fruit package comprising a container having a substantially rectangular container bottom and four container side walls that extend upward from the entire periphery of the container bottom and form a container with an open top, a buffer tray having a soft fruit storage section arranged inside the container and provided with multiple recesses for storing multiple soft fruits, multiple soft fruits stored in the soft fruit storage section, and a heat shrinkable film that covers the multiple soft fruits and the entire periphery of the container, wherein the soft fruit package satisfies the following conditions. Condition (a): With respect to the soft fruit storage section of the buffer tray, the surface opposite to the surface in contact with the multiple soft fruits is in contact with the bottom of the container. Condition (b): The multiple soft fruits are in contact with the heat shrink film.

[10] A soft fruit package comprising a container having a substantially rectangular container bottom having a soft fruit storage section provided with multiple recesses for storing multiple soft fruits, and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a multiple soft fruits stored in the soft fruit storage section, and a heat shrink film that covers the multiple soft fruits and the entire periphery of the container, wherein the following condition is met: Condition (b): The multiple soft fruits are in contact with the heat shrink film.

[11] The soft fruit package according to [9] or

[10] , wherein the soft fruits are strawberries.

[12] The soft fruit packaging according to [9] or

[10] , wherein the heat shrinkable film is provided with a number of small through-holes, the small through-holes being concentrated at the top of the open container.

[13] The soft fruit packaging according to [9] or

[10] , wherein the heat shrinkable film comprises a layer containing an antifungal agent and / or an antifogging agent.

[14] The soft fruit packaging according to [9] or

[10] , wherein the heat shrinkable film has a heat shrinkage rate of 58% to 67% in both the MD (longitudinal direction) and TD (width direction) at 120°C, a heat shrinkage force of 0.25 N / cm or less in the MD at 120°C, a heat shrinkage force of 0.22 N / cm or less in the TD at 120°C, a tensile modulus of elasticity of 0.25 GPa to 0.29 GPa in the MD, and a tensile modulus of elasticity of 0.25 GPa to 0.27 GPa in the TD.

[15] The soft fruit packaging according to [9] or

[10] , wherein the heat shrinkable film comprises a plant-derived polyethylene resin.

[16] The soft fruit packaging according to [9], wherein the buffer tray is made of a foamed synthetic resin sheet, and the foamed synthetic resin sheet is made of at least one foamed synthetic resin selected from the group consisting of foamed polystyrene, foamed polyethylene, foamed polypropylene, and foamed polyurethane.

[17] The soft fruit packaging described in [9] or

[10] , wherein the reduction rate of the electrical conductivity of the aqueous solution in which the soft fruit was immersed after a vibration test, measured by the evaluation method below, is 20% or more compared to the soft fruit packaging described in [9] or

[10] , in which the soft fruit packaging described in [9] or

[10] is covered with a non-heat-shrinkable film instead of a heat-shrinkable film so as to cover at least the upper part of the opening of the container. [Electrical conductivity of aqueous solution in which soft fruit was immersed after a vibration test] (1) Vibration test A sinusoidal uniform sweep vibration test is performed for 30 minutes on a container containing one or more soft fruit packagings using a vibration test apparatus under the following conditions. (Conditions for vibration test) Lower frequency limit: 10 Hz, Upper frequency limit: 40 Hz, Sweep time: 10 minutes, Number of sweeps: 3 times, Vibration direction: Simultaneous of three axes: X axis (horizontal direction), Y axis (horizontal direction), Z axis (vertical direction), Gravitational acceleration: 0 G to 3 G (m / s). ２ (Dependent on frequency). (2) Electrical conductivity measurement After the vibration test, the soft fruits removed from the container are placed in six times the total weight of the soft fruits in pure water (electrical conductivity 1.0 μS / cm), the aqueous solution in which the soft fruits are immersed is stirred for 30 minutes, and the electrical conductivity measured using an electrical conductivity meter is taken as the electrical conductivity of the aqueous solution in which the soft fruits were immersed after the vibration test.

[0009] This invention provides a novel soft fruit packaging material that prevents damage to soft fruits caused by vibration during transportation.

[0010] Figure 1 is a schematic perspective view showing one embodiment (single-layer flat packing) of the soft fruit packaging of the present invention. Figure 2 is a schematic top view showing one embodiment (single-layer flat packing) of the soft fruit packaging of the present invention. Figure 3 is a schematic cross-sectional view along the line A-A' shown in Figure 2. Figure 4 is a schematic perspective view showing one embodiment (upper and lower two-layer packing) of the soft fruit packaging of the present invention. Figure 5(a) is a schematic top view showing one embodiment (upper and lower two-layer packing) of the soft fruit packaging of the present invention. Figure 5(b) is a schematic bottom view showing one embodiment (upper and lower two-layer packing) of the soft fruit packaging of the present invention. Figure 6 is a schematic cross-sectional view along the line B-B' shown in Figure 5(a). Figure 7 is a schematic cross-sectional view of another embodiment (single-layer flat packing) of the soft fruit packaging of the present invention. Figure 8 is a schematic cross-sectional view of another embodiment (upper and lower two-layer packing) of the soft fruit packaging of the present invention. Figure 9 is a graph showing the electrical conductivity of the soft fruit immersion liquid after the vibration test. Figure 10 is a graph showing the percentage of damaged area of ​​the soft fruit after the vibration test. Figure 11 is a schematic exploded perspective view showing the configuration of one embodiment of the soft fruit packaging of the present invention. Figure 12 is a schematic top view showing one embodiment of the soft fruit packaging of the present invention. Figure 13 is a schematic cross-sectional view along the line C-C' shown in Figure 12. Figure 14 is a schematic exploded perspective view showing the configuration of one embodiment of the soft fruit packaging of the present invention. Figure 15 is a schematic top view showing one embodiment of the soft fruit packaging of the present invention. Figure 16 is a schematic cross-sectional view along the line D-D' shown in Figure 15. Figure 17 is a graph showing the electrical conductivity of the soft fruit immersion liquid after a vibration test.

[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. Figures 1 to 8 and 11 to 16 attached to this specification are schematic diagrams, and for ease of understanding, the shape, scale, and aspect ratio of each part have been modified or exaggerated from the actual object. Furthermore, hatching in the drawings indicates a cross-section of a component.

[0012] [Soft Fruit Packaging (Single Layer Flat Packing)] The present invention relates to soft fruit packaging comprising a container having a flat, substantially rectangular container bottom and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a plurality of soft fruits stored in a single layer flat in the storage space surrounded by the container side walls, and a heat shrinkable film that covers the plurality of soft fruits and the entire periphery of the container, wherein the plurality of soft fruits satisfy the following conditions: Condition (1): The plurality of soft fruits are in contact with at least one of each other. Condition (2): At least one soft fruit is in contact with each of the four container side walls forming the container. Condition (3): The plurality of soft fruits are in contact with the heat shrinkable film. Condition (4): The plurality of soft fruits are in contact with the container bottom.

[0013] Figure 1 shows a soft fruit package 1 in which multiple soft fruits 6 are packed in a single layer in the storage space 5 of a container 2 in a flat arrangement (the soft fruits are packed horizontally to the bottom of the container without being stacked) to satisfy conditions (1), (2), (3), and (4), and the multiple soft fruits 6 and the entire perimeter of the container 2 are wrapped with a heat-shrinkable film 7. In Figures 1 and 2, the heat-shrinkable film 7 is shown in light gray.

[0014] <Container> As shown in Figure 1, the container 2 has a flat, substantially rectangular container bottom 3 and four container side walls 4 that extend upward from the entire periphery of the container bottom 3, forming a container with an open top. The container 2 also has a storage space 5 surrounded by the container side walls 4. The container 2 is made of a thermoplastic resin such as polyethylene terephthalate, polystyrene, or polypropylene. The container bottom 3 and the container side walls 4 are integrally formed, and their thickness is approximately 0.10 mm to 0.50 mm.

[0015] "Flat" means that the container is flat overall, and the container bottom 3 may, for example, include a stepped portion with a slight difference in height, a slightly inclined portion, or an uneven surface with a slight difference in height. The four container side walls 4 do not need to extend upward perpendicular (90 degrees) to the container bottom 3, and may be inclined.

[0016] <Soft Fruits> In this invention, soft fruits refer to fruits with thin skins and soft flesh that are easily damaged by vibrations during transport. Examples of soft fruits include strawberries, figs, loquats, plums, mangoes, nectarines, apricots, pomegranates, peaches, and cherries. The soft fruit packaging of this invention is particularly effective for soft fruits that are small, are usually stored together in containers, and whose commercial value is significantly reduced if damaged by vibrations during transport. Among the specific examples of soft fruits mentioned above, it is preferably used for strawberries, peaches, and cherries. Soft fruit 6 in Figures 1 to 8 and Figures 11 to 16 shows a strawberry as an example.

[0017] In the present invention, it is preferable that the multiple soft fruits 6 are of a certain degree of uniformity in size. For example, among the multiple soft fruits 6 contained in the soft fruit packaging 1, the ratio of the diameter of the largest soft fruit 6 to the diameter of the smallest soft fruit 6 (maximum / minimum) is preferably 1.5 or less, more preferably 1.3 or less, and particularly preferably 1.1 or less.

[0018] <Conditions (Single-Layer Flat Packing)> The soft fruit packaging body 1 (single-layer flat packing) of the present invention is characterized in that a plurality of soft fruits 6 are stored in a single layer flat in the storage space 5 of the container 2 so as to satisfy conditions (1), (2), (3) and (4).

[0019] As shown in Figure 2, condition (1) is that multiple soft fruits 6 must be in contact with at least one other. If there are soft fruits 6 that are not in contact with any other soft fruits 6, those soft fruits 6 may repeatedly collide with other soft fruits 6 or the side wall 4 of the container due to vibration, and therefore there is a risk that the surface of the soft fruits 6 may be damaged. Furthermore, it is preferable that multiple soft fruits 6 be in contact with at least two other soft fruits 6. Also, it is preferable that multiple soft fruits 6 be arranged in a staggered pattern, as shown in Figure 2.

[0020] As shown in Figure 3, condition (2) is that at least one soft fruit 6 is in contact with each of the four container side walls 4 that form the container 2. By having the soft fruit 6 in contact with each of the four container side walls 4, the entire group of soft fruits stored in the storage space 5 is fixed in place so as not to move. If the soft fruit 6 is not in contact with the container side walls 4, vibrations may cause the soft fruit 6 near the container side walls 4 to repeatedly collide with the container side walls 4, which may cause damage to the surface of the soft fruit 6. Furthermore, as shown in Figure 2, it is preferable that at least one soft fruit 6 is in contact with each of the four container side walls 4 that form the container 2, and that at least one other soft fruit 6 is in contact with two container side walls 4 simultaneously.

[0021] As shown in Figure 3, condition (3) is that the multiple soft fruits 6 are in contact with the heat-shrinkable film 7. By having the multiple soft fruits 6 in contact with the heat-shrinkable film 7, the entire group of soft fruits stored in the storage space 5 is fixed in place so as not to move. If the soft fruits 6 are not in contact with the heat-shrinkable film 7, the soft fruits 6 may repeatedly collide with the bottom of the container 3 or other soft fruits 6 due to vibration, and therefore there is a risk of damage to the surface of the soft fruits 6.

[0022] As shown in Figure 3, condition (4) is that multiple soft fruits 6 are in contact with the bottom of the container 3. If there are soft fruits 6 that are not in contact with the bottom of the container 3, vibrations may cause the soft fruits 6 to hit the bottom of the container 3 forcefully, which may cause damage to the surface of the soft fruits 6.

[0023] It is preferable that the soft fruits 6 stored in the storage space 5 protrude at least 0.01 mm above the virtual plane 9 connecting the upper ends 4A of the container side walls, as shown in Figure 3. By storing the soft fruits 6 in this manner, the heat shrink film 7 can more firmly fix the soft fruits 6 stored in the storage space 5. In a single-layer flat packing, it is preferable that more than half of the soft fruits are stored in this manner, and it is particularly preferable that all of the soft fruits are stored in this manner.

[0024] As shown in Figure 7, in another embodiment of single-layer flat packing, for example, multiple soft fruits 6 may be in contact with the bottom of the container 3 via a conventionally known elastic and flexible foamed synthetic resin sheet 8. Furthermore, as shown in Figure 7, at least one soft fruit 6 may be in contact with each of the four container side walls 4 forming the container 2 via a conventionally known elastic and flexible foamed synthetic resin sheet 8. Examples of foamed synthetic resins include expanded polystyrene, expanded polyethylene, expanded polypropylene, and expanded polyurethane. The foamed synthetic resin sheet 8 is highly flexible, which not only prevents damage to the surface of the soft fruit 6 due to pressure and friction, but also provides the following effects to the soft fruit packaging 1. That is, by laying the foamed synthetic resin sheet 8 in contact with the bottom of the container 3, multiple soft fruits 6 can be stored so that they protrude more above the virtual flat surface 9 by the thickness of the foamed synthetic resin sheet 8 from the bottom of the container 3. Therefore, the heat-shrinkable film 7 can more firmly fix the soft fruit 6 in the storage space 5, and damage to the soft fruit 6 due to vibration can be more effectively prevented. Furthermore, by laying a foamed synthetic resin sheet 8, as shown in Figure 7, which is in contact with the bottom 3 of the container and with each of the four side walls 4 of the container, the foamed synthetic resin sheet 8 occupies the storage space 5 by its volume, making the gaps between the soft fruits 6 smaller. Therefore, even if vibrations are applied, multiple soft fruits 6 are more likely to be transported while satisfying conditions (1), (2), and (3), and damage to the soft fruits due to vibrations can be further prevented.

[0025] For soft fruits in soft fruit packaging, the electrical conductivity of the aqueous solution in which the soft fruits were immersed after a vibration test, measured according to the evaluation method below, is preferably reduced by 20% or more compared to the electrical conductivity of soft fruit packaging in which the soft fruit was packaged with a non-heat-shrinkable film instead of a heat-shrinkable film, so as to cover at least the upper part of the container opening, as a reference. [Electrical conductivity of aqueous solution in which soft fruits were immersed after a vibration test] (1) Vibration test Using a vibration test apparatus, a sinusoidal uniform sweep vibration test is performed for 30 minutes on a container containing one or more soft fruit packagings under the following conditions. (Conditions for vibration test) Lower frequency limit: 10 Hz, Upper frequency limit: 40 Hz, Sweep time: 10 minutes, Number of sweeps: 3, Vibration direction: Simultaneous of three axes: X-axis (horizontal), Y-axis (horizontal), Z-axis (vertical), Gravitational acceleration: 0G to 3G (m / s²) ２ (Dependent on frequency). (2) Electrical conductivity measurement After the vibration test, the soft fruits removed from the container are placed in six times the total weight of the soft fruits in pure water (electrical conductivity 1.0 μS / cm), the aqueous solution in which the soft fruits are immersed is stirred for 30 minutes, and the electrical conductivity measured using an electrical conductivity meter is taken as the electrical conductivity of the aqueous solution in which the soft fruits were immersed after the vibration test. The reduction rate of the electrical conductivity is calculated by the following formula: Reduction rate of electrical conductivity = ((EC Ｎ -EC Ｓ ) / EC Ｎ ) × 100 EC Ｎ : Electrical conductivity measured by the above evaluation method for a soft fruit packaging body of the present invention in which the soft fruit packaging body is packaged with a non-heat-shrinkable film instead of a heat-shrinkable film so as to cover at least the upper part of the container opening. EC Ｓ: Electrical conductivity measured by the above evaluation method for the soft fruit packaging of the present invention. The reduction rate of the electrical conductivity measured by the above evaluation method is more preferably 30% or more, even more preferably 40% or more, even more preferably 50% or more, particularly preferably 60% or more, and particularly preferably 70% or more. As the non-heat shrinkable film, a so-called overlay film used for conventionally known fruit packaging is used. Examples of such overlay films include biaxially oriented polystyrene film and biaxially oriented polypropylene film.

[0026] [Soft Fruit Packaging (Two-Tiered)] The present invention relates to soft fruit packaging comprising a container having a flat, substantially rectangular container bottom and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a plurality of soft fruits stored in a storage space surrounded by the container side walls in a two-tiered arrangement, and a heat-shrinkable film that covers the plurality of soft fruits and the entire periphery of the container, wherein the plurality of soft fruits satisfy the following conditions: Condition (1): The plurality of soft fruits are in contact with at least one of each other. Condition (2): At least one soft fruit is in contact with each of the four container side walls forming the container. Condition (3'): Of the plurality of soft fruits, the soft fruits stored in the upper tier are in contact with the heat-shrinkable film, and the soft fruits stored in the lower tier are in contact with the soft fruits stored in the upper tier. Condition (4'): Of the plurality of soft fruits, the soft fruits stored in the lower tier are in contact with the container bottom.

[0027] Figure 4 shows a soft fruit package 1 in which multiple soft fruits 6 are stored in the storage space 5 of a container 2 in two layers, top and bottom, satisfying conditions (1), (2), (3'), and (4'), and the multiple soft fruits 6 and the container 2 are wrapped in a heat-shrinkable film 7 that covers the entire perimeter. In Figures 4 and 5, the heat-shrinkable film 7 is shown in light gray.

[0028] Container 2 is as described above under <Container>. Soft fruit 6 is as described above under <Soft fruit>.

[0029] <Conditions (Two-tiered packing)> The soft fruit packaging 1 (two-tiered packing) of the present invention is characterized in that a plurality of soft fruits 6 are packed in two layers, top and bottom, in the storage space 5 of the container 2 so as to satisfy conditions (1), (2), (3') and (4').

[0030] As shown in Figures 5(a) and (b), condition (1) is that multiple soft fruits 6 must be in contact with at least one other. If there are soft fruits 6 that are not in contact with any other soft fruits 6, those soft fruits 6 may repeatedly collide with other soft fruits 6 or the side wall 4 of the container due to vibration, and therefore there is a risk that the surface of the soft fruits 6 may be damaged. Furthermore, it is preferable that multiple soft fruits 6 are in contact with at least two other soft fruits 6. Moreover, it is more preferable that condition (1') is as follows: that soft fruits 6 stored in the upper section are in contact with at least one soft fruit 6 stored in the upper section, and soft fruits 6 stored in the lower section are in contact with at least one soft fruit 6 stored in the lower section [condition (1')]. Furthermore, it is preferable that the soft fruits 6 stored in the upper and / or lower sections are stored in a staggered pattern.

[0031] As shown in Fig. 6, condition (2) means that at least one soft fruit 6 contacts each of the four container side wall portions 4 forming the container 2. By having a soft fruit 6 contact each of the four container side wall portions 4, the entire plurality of soft fruits stored in the storage space 5 is fixed so as not to move. If the soft fruit 6 does not contact the container side wall portion 4, there is a possibility that the soft fruit 6 near the container side wall portion 4 will repeatedly hit the container side wall portion 4 due to vibration, and thus there is a risk of damage to the surface of the soft fruit 6. Also, as shown in Fig. 5(a), it is preferable that at least one soft fruit 6 contacts each of the four container side wall portions 4 forming the container 2, and at least one other soft fruit 6 contacts two container side wall portions 4 simultaneously. Further, it is more preferable that at least one soft fruit 6 stored in the upper stage contacts each of the four container side wall portions 4 forming the container 2, at least one other soft fruit 6 stored in the upper stage contacts two container side wall portions 4 simultaneously, and at least one soft fruit 6 stored in the lower stage contacts two container side wall portions 4 simultaneously.

[0032] As shown in Fig. 6, condition (3') means that among the plurality of soft fruits 6, the soft fruits 6 stored in the upper stage contact the heat-shrinkable film 7, and the soft fruits 6 stored in the lower stage contact the soft fruits 6 stored in the upper stage. By having the plurality of soft fruits 6 stored in the upper stage contact the heat-shrinkable film 7, the entire plurality of soft fruits stored in the storage space 5 is fixed so as not to move. On the other hand, if the soft fruits 6 stored in the lower stage do not contact the soft fruits 6 stored in the upper stage, there is a possibility that the soft fruits 6 stored in the upper stage will repeatedly hit mainly the container bottom 3 or other soft fruits 6 due to vibration, and thus there is a risk of damage to the surface of the soft fruit 6.

[0033] As shown in Fig. 6, condition (4') means that among the plurality of soft fruits, the soft fruits 6 stored in the lower stage contact the container bottom 3. If there is a soft fruit 6 that does not contact the container bottom 3, there is a possibility that the soft fruit 6 will hit the container bottom 3 forcefully due to vibration, and thus there is a risk of damage to the surface of the soft fruit 6.

[0034] As shown in Fig. 6, it is preferable that the soft fruits 6 stored in the upper layer protrude upward by at least 0.01 mm or more from the virtual plane portion 9 connecting the upper ends 4A of the container side wall portions. By storing the soft fruits 6 stored in the upper layer in this way, the heat-shrinkable film 7 can more strongly fix the soft fruits 6 stored in the storage space 5. It is preferable that more than half of all the soft fruits stored in the upper layer in the upper and lower double-layer packing are stored in this way, and it is particularly preferable that all the soft fruits stored in the upper layer are stored in this way.

[0035] As shown in Fig. 8, as another embodiment, for example, a plurality of soft fruits 6 may contact the container bottom portion 3 via a conventionally known flexible foamed synthetic resin sheet 8 having elasticity. Further, at least one soft fruit 6 may contact each of the four container side wall portions 4 forming the container 2 via a conventionally known flexible foamed synthetic resin sheet 8 having elasticity. Also, as shown in Fig. 8, by laying the foamed synthetic resin sheet 8 contacting the container bottom portion 3, a plurality of soft fruits 6 stored in the upper layer can be stored so as to protrude upward from the virtual plane portion 9 by the thickness of the foamed synthetic resin sheet 8 from the container bottom portion 3. Therefore, the heat-shrinkable film 7 can more strongly fix the soft fruits 6 in the storage space 5, and damage to the soft fruits 6 due to vibration can be further prevented. Further, when the foamed synthetic resin sheet 8 contacting the container bottom portion 3 and contacting each of the four container side wall portions 4 is laid, the foamed synthetic resin sheet 8 occupies the inside of the storage space 5 by its volume, and the gap between the soft fruits 6 can be made smaller. Therefore, even if vibration is applied, a plurality of soft fruits 6 can be easily transported while satisfying the conditions (1), (2) and (3'), and damage to the soft fruits due to vibration can be further prevented.

[0036] With respect to soft fruits in a soft fruit packaging, the electrical conductivity of the aqueous solution in which the soft fruits were immersed after the vibration test measured by the above evaluation method is preferably 20% or more, using the electrical conductivity of a soft fruit packaging in which the soft fruit packaging (two-tiered packaging) of the present invention is packaged with a non-heat-shrinkable film instead of a heat-shrinkable film so as to cover at least the upper part of the container opening as a reference. More preferably, the reduction rate of the electrical conductivity measured by the above evaluation method is 30% or more, even more preferably 40% or more, even more preferably 50% or more, particularly preferably 60% or more, and particularly preferably 70% or more.

[0037] [Soft Fruit Packaging (with Cushion Tray Having Soft Fruit Storage Section)] The present invention relates to a soft fruit packaging comprising a container having a substantially rectangular container bottom and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a cushion tray disposed inside the container and having a soft fruit storage section provided with a plurality of recesses for storing a plurality of soft fruits, a plurality of soft fruits stored in the soft fruit storage section, and a heat shrinkable film that covers the plurality of soft fruits and the entire periphery of the container, wherein the soft fruit packaging satisfies the following conditions: Condition (a): With respect to the soft fruit storage section of the cushion tray, the surface opposite to the surface that contacts the plurality of soft fruits is in contact with the container bottom. Condition (b): The plurality of soft fruits are in contact with the heat shrinkable film.

[0038] Figure 11 shows a schematic exploded perspective view of the soft fruit packaging 1, which consists of a heat-shrinkable film 7, multiple soft fruits 6 (only one soft fruit 6 is shown as a representative in Figure 11), a buffer tray 10, and a container 2. In Figures 11 and 12, the heat-shrinkable film 7 is shown in light gray.

[0039] <Container> As shown in Figures 11 and 13, the container 2 has a substantially rectangular container bottom 3 and four container side walls 4 that extend upward from the entire periphery of the container bottom 3 and form a container with an open top. The container 2 also has a storage space 5 surrounded by the container side walls 4. The container 2 is made of a thermoplastic resin such as polyethylene terephthalate, polystyrene, or polypropylene. The container bottom 3 and the container side walls 4 are formed integrally, and their thickness is approximately 0.10 mm to 0.50 mm.

[0040] The container bottom 3 does not need to be flat. The container bottom 3 may, for example, include stepped sections with height differences, inclined sections, or uneven surfaces with height differences. The four container side walls 4 do not need to extend upward perpendicular (90 degrees) to the container bottom 3; they may be inclined. The soft fruit 6 is as described above under <Soft Fruit>.

[0041] <Cushioning Tray> The cushioning tray 10 is placed inside the container 2 and has a soft fruit storage section 11 provided with multiple recesses 11A for storing multiple soft fruits 6. The cushioning tray 10 is made of, for example, the foamed synthetic resin mentioned in the foamed synthetic resin sheet 8. The cushioning tray 10 provides the following effects to the soft fruit packaging 1. That is, by storing the soft fruits 6 in the soft fruit storage section 11, it prevents damage such as pressure and rubbing of the soft fruits 6's surfaces against each other. Also, multiple soft fruits 6 can be stored so that they protrude more from the bottom of the container 3 than the virtual flat surface 9 shown in Figure 13 by the thickness of the cushioning tray 10. Therefore, the heat shrink film 7 can more firmly fix the soft fruits 6 in the fruit storage section 11, and damage to the soft fruits 6 due to vibration can be further prevented. Furthermore, because the soft fruits 6 are stored in the soft fruit storage section 11, even if vibration is applied to the cushioning tray 10, the movement of the soft fruits 6 is restricted, and damage to the soft fruits 6 due to vibration can be further prevented. Multiple soft fruits 6 stored in the buffer tray 10 may be in contact with other soft fruits 6.

[0042] <Condition (with buffer tray having soft fruit storage section)> The soft fruit packaging body 1 of the present invention (with buffer tray having soft fruit storage section) is characterized in that a buffer tray 10 is arranged in the storage space 5 of the container 2 to satisfy condition (a), and a plurality of soft fruits 6 are stored to satisfy condition (b).

[0043] As shown in Figure 13, condition (a) is that, with respect to the soft fruit storage section 11 of the buffer tray 10, the side 11B (hereinafter also referred to as the back surface 11B) opposite to the side that comes into contact with the soft fruits is in contact with the bottom of the container 3. By the back surface 11B coming into contact with the bottom of the container 3, vibrations prevent the buffer tray 10 from forcefully hitting the bottom of the container 3, and therefore damage to the surface of the soft fruits 6 stored in the soft fruit storage section 11 of the buffer tray 10 is less likely to occur.

[0044] As shown in Figure 13, condition (a) is that the multiple soft fruits 6 are in contact with the heat-shrinkable film 7. By the multiple soft fruits 6 being in contact with the heat-shrinkable film 7, the multiple soft fruits 6 stored in the soft fruit storage section 11 are fixed in place so as not to move.

[0045] It is preferable that the multiple soft fruits 6 stored in the soft fruit storage section 11 protrude at least 0.01 mm above the virtual plane 9 connecting the upper ends 4A of the container side walls, as shown in Figure 13. This arrangement allows the soft fruits 6, with the heat-shrinkable film 7 inside, to be more firmly secured by the soft fruit storage section 11. It is preferable that more than half of the soft fruits stored in the soft fruit storage section 11 are stored in this manner, and it is particularly preferable that all of the soft fruits are stored in this manner.

[0046] With respect to soft fruits in a soft fruit packaging, the electrical conductivity of the aqueous solution in which the soft fruits were immersed after the vibration test measured by the above evaluation method is preferably 20% or more, using as a reference the electrical conductivity of a soft fruit packaging in which the soft fruit packaging (with a buffer tray having a soft fruit storage section) of the present invention is packaged with a non-heat-shrinkable film instead of a heat-shrinkable film so as to cover at least the upper part of the container opening. More preferably, the reduction rate of the electrical conductivity measured by the above evaluation method is 30% or more, even more preferably 40% or more, even more preferably 50% or more, particularly preferably 60% or more, and particularly preferably 70% or more.

[0047] [Soft Fruit Packaging (Container with Soft Fruit Storage Compartment at the Bottom)] The present invention relates to a soft fruit packaging comprising a container having a substantially rectangular bottom with a soft fruit storage compartment provided with a plurality of recesses for storing a plurality of soft fruits, and four container side walls extending upward from the entire periphery of the bottom of the container and forming a container with an open top, a plurality of soft fruits stored in the soft fruit storage compartment, and a heat-shrinkable film that covers the plurality of soft fruits and the entire periphery of the container, wherein the soft fruit packaging satisfies the following conditions: Condition (a): The plurality of soft fruits are in contact with the heat-shrinkable film.

[0048] Figure 14 shows a schematic exploded perspective view of the soft fruit packaging 1, consisting of a heat-shrinkable film 7, multiple soft fruits 6 (only one soft fruit 6 is shown as a representative in Figure 14), and a container 22. In Figures 14 and 15, the heat-shrinkable film 7 is shown in light gray.

[0049] <Container> As shown in Figures 14 and 16, the container 22 has a substantially rectangular container bottom 23 having a soft fruit storage section 111 with multiple recesses 111A for storing multiple soft fruits 6, and four container side walls 24 that extend upward from the entire periphery of the container bottom 23 and form a container with an open top. The container 22 is made of a thermoplastic resin such as polyethylene terephthalate, polystyrene, or polypropylene. The container bottom 23 and the container side walls 24 are integrally formed, and their thickness is approximately 0.10 mm to 0.50 mm.

[0050] The bottom of the container 23 has a soft fruit storage section 111 provided with a plurality of recesses 111A. In addition to the plurality of recesses 111A, the bottom of the container 23 may also have stepped sections with height differences, inclined sections, or uneven surfaces with height differences. The presence of the soft fruit storage section 111 provided with a plurality of recesses 111A in the bottom of the container 23 provides the following effects to the soft fruit packaging 1. Specifically, storing the soft fruits 6 in the soft fruit storage section 111 prevents damage to the soft fruits 6 caused by pressure and friction on each other's surfaces. Furthermore, storing the soft fruits 6 in the soft fruit storage section 111 restricts the movement of the soft fruits 6 even if the container 22 is subjected to vibration, further preventing damage to the soft fruits 6 due to vibration. Furthermore, a thermoplastic synthetic resin sheet may be laid or attached to the bottom of the container 23, and the soft fruits 6 may be stored on top of it. By doing so, the soft fruit storage section 111 and the soft fruit 6 will not come into direct contact with each other, thereby further preventing damage to the soft fruit 6 due to vibration. The thermoplastic synthetic resin sheet is a thin film sheet made of polyethylene, polypropylene, polyurethane, polystyrene, etc. The thickness of the sheet is 5 μm to 250 μm, preferably 10 μm to 150 μm, and the thickness can be appropriately changed depending on the type of soft fruit. Multiple soft fruits 6 stored in the soft fruit storage section 111 may come into contact with other soft fruits 6. The four container side walls 24 do not need to extend upward so as to be perpendicular (90 degrees) to the container bottom 23, and may be inclined. The soft fruit 6 is as described above under <Soft Fruit>.

[0051] <Condition (container has a soft fruit storage section at the bottom)> The soft fruit packaging body 1 of the present invention (container has a soft fruit storage section at the bottom) is characterized in that a plurality of soft fruits 6 are stored in the soft fruit storage section 111 of the container 22 in such a way that condition (a) is met.

[0052] As shown in Figure 16, condition (a) is that the multiple soft fruits 6 are in contact with the heat-shrinkable film 7. By the multiple soft fruits 6 being in contact with the heat-shrinkable film 7, the multiple soft fruits 6 stored in the soft fruit storage section 111 are fixed in place so as not to move.

[0053] It is preferable that the multiple soft fruits 6 stored in the soft fruit storage section 111 protrude at least 0.01 mm above the virtual plane 9 connecting the upper ends 24A of the container side walls, as shown in Figure 16. This arrangement allows the soft fruits 6, in which the heat-shrinkable film 7 is stored, to be more firmly secured by the soft fruit storage section 111. It is preferable that more than half of the soft fruits stored in the soft fruit storage section 111 are stored in this manner, and it is particularly preferable that all of the soft fruits are stored in this manner.

[0054] With respect to soft fruits in a soft fruit packaging, the electrical conductivity of the aqueous solution in which the soft fruits were immersed after the vibration test measured by the above evaluation method is preferably 20% or more, using as a reference the electrical conductivity of a soft fruit packaging in which the soft fruit packaging of the present invention (having a soft fruit storage section at the bottom of the container) is packaged with a non-heat-shrinkable film instead of a heat-shrinkable film so as to cover at least the upper part of the opening of the container. More preferably, the reduction rate of the electrical conductivity measured by the above evaluation method is 30% or more, even more preferably 40% or more, even more preferably 50% or more, particularly preferably 60% or more, and particularly preferably 70% or more.

[0055] <Heat-Shrinkable Film> The soft fruit packaging body of the present invention comprises a heat-shrinkable film that covers the plurality of soft fruits and the entire perimeter of the container.

[0056] Preferably, the heat shrinkable film has a thermal shrinkage rate of 4% to 9% in the MD (longitudinal direction) at 80°C, and a thermal shrinkage rate of 3% to 8% in the TD (width direction) at 80°C. Furthermore, preferably, the heat shrinkable film has a thermal shrinkage rate of 15% to 20% in the MD at 100°C, and a thermal shrinkage rate of 18% to 23% in the TD at 100°C. Also, preferably, the heat shrinkable film has thermal shrinkage rates of 58% to 67% in both the MD and TD at 120°C. The thermal shrinkage rate is measured in accordance with ASTM-D1204.

[0057] Preferably, the heat shrinkable film has a MD heat shrinkage force of 0.05 N / cm to 0.10 N / cm at 80°C and a TD heat shrinkage force of 0.001 N / cm to 0.08 N / cm at 80°C. Furthermore, preferably, the heat shrinkable film has a MD heat shrinkage force of 0.05 N / cm to 0.20 N / cm at 100°C and a TD heat shrinkage force of 0.02 N / cm to 0.18 N / cm at 100°C. Also, preferably, the heat shrinkable film has an MD heat shrinkage force of 0.25 N / cm or less at 120°C and a TD heat shrinkage force of 0.22 N / cm or less at 120°C. The heat shrinkage force is measured in accordance with ASTM-D2838.

[0058] The heat-shrinkable film preferably has a tensile modulus of MD of 0.25 GPa to 0.29 GPa and a tensile modulus of TD of 0.25 GPa to 0.27 GPa. The tensile modulus is measured in accordance with JIS-Z1702.

[0059] A heat-shrinkable film is a laminated film consisting of layers made of polyolefin resin. A layer made of polyolefin resin refers to a layer whose resin component is solely polyolefin resin, with the optional inclusion of other additives.

[0060] As the polyolefin resin in the layer made of the above polyolefin resin, a polyethylene resin, a polypropylene resin, a polybutene resin, or a cyclic olefin copolymer is preferable, and a polyethylene resin is more preferable. The polyolefin resin contained in the layer made of the polyolefin resin may be one kind or a plurality of kinds.

[0061] Examples of the above polyethylene resin include an ethylene homopolymer, an ethylene-α-olefin copolymer, an ethylene-vinyl acetate copolymer, etc. Examples of the above polyethylene resin include high-density polyethylene, medium-density polyethylene, low-density polyethylene (LDPE) (preferably linear low-density polyethylene (LLDPE)), and ultra-low-density polyethylene. Examples of ultra-low-density polyethylene include linear ultra-low-density polyethylene (referred to as "LVLDPE", "LULDPE").

[0062] Polyethylene resins are classified by density based on JIS K 6922. In this classification, a polyethylene resin with a density of 0.942 g / cm ３ or more is regarded as high-density polyethylene (HDPE), a polyethylene resin with a density of 0.930 g / cm ３ or more and less than 0.942 g / cm ３ is regarded as medium-density polyethylene (MDPE), a polyethylene resin with a density of 0.910 g / cm ３ or more and less than 0.930 g / cm ３ is regarded as low-density polyethylene (LDPE), and a polyethylene resin with a density of less than 0.910 g / cm ３ is regarded as ultra-low-density polyethylene. The above density means a value measured according to JIS K 6922. As a method for measuring density, specifically, there is a method of measuring density with a density gradient tube according to JIS K 6922.

[0063] An ethylene-α-olefin copolymer refers to a copolymer of ethylene and an α-olefin. Examples of the above α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. These α-olefins can be used individually or in combination of two or more. As the above ethylene-α-olefin copolymer, a copolymer of ethylene and at least one comonomer selected from propylene comonomer, butene comonomer, hexene comonomer, and octene comonomer is generally readily available and can be suitably used. Ethylene-α-olefin copolymers are sometimes referred to as polyethylene elastomers. The polymerization catalyst used in producing ethylene-α-olefin copolymers is not particularly limited, but examples include multi-site catalysts and single-site catalysts.

[0064] In the present invention, the polyethylene resin may be not only petroleum-derived polyethylene resin but also plant-derived polyethylene resin. Specifically, examples of the polyethylene resin include petroleum-derived polyethylene resin, a mixed resin of petroleum-derived polyethylene resin and plant-derived polyethylene resin, and plant-derived polyethylene resin. The heat-shrinkable film, which is a component of the soft fruit packaging body of the present invention, preferably contains plant-derived polyethylene resin.

[0065] The plant-derived polyethylene resins mentioned above are polyethylene resins made from renewable resources other than fossil fuels, particularly bioethanol derived from plants such as sugarcane.

[0066] Examples of plant-derived polyethylene resins include homopolymers of plant-derived ethylene, and copolymers of plant-derived ethylene and α-olefins with plant-derived ethylene as the main component (ethylene-α-olefin copolymers containing 90% by mass or more of plant-derived ethylene units). These can be used individually or in combination of two or more. Examples of the α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. These α-olefins can be used individually or in combination of two or more.

[0067] Since there is no difference in physical properties such as molecular weight, mechanical properties, and thermal properties between plant-derived resins and petroleum-derived resins, the biomass degree specified in ISO 16620 or ASTM D6866 is generally used to distinguish them. In the atmosphere, 10 １２ Radioactive carbon at a rate of 1 per individual １４ Since carbon (C) is present and this ratio does not change even with atmospheric carbon dioxide, this ratio does not change even in plants that fix this carbon dioxide through photosynthesis. For this reason, the carbon in plant-derived resins is radioactive carbon. １４ It contains carbon. In contrast, the carbon in petroleum-derived resins is radioactive carbon. １４ It contains almost no carbon. Therefore, the radioactive carbon in the resin is analyzed using an accelerator mass spectrometer. １４ By measuring the concentration of C, the proportion of plant-derived resin in the resin, i.e., the biomass content, can be determined.

[0068] The heat-shrinkable film is preferably crosslinked. When crosslinking the heat-shrinkable film, methods of crosslinking include, for example, irradiation with energy rays such as electron beams, ultraviolet rays, X-rays, alpha rays, and gamma rays, with electron beam irradiation being preferred. The preferred irradiation dose range for crosslinking is, for example, 30 kGy to 130 kGy.

[0069] The heat-shrinkable film may contain layers other than those made of polyolefin resin, but it is preferable that the laminated film consists only of layers made of polyolefin resin. Each layer constituting the laminated film may have the same composition or different compositions. As for the layer structure of the laminated film, for example, a layer structure in which the surface layer is the outermost layer and the inner layers include intermediate layers and core layers can be cited, and more specifically, the following examples can be given. With this layer structure, the effects of the present invention are exhibited even more significantly. • Surface layer / Core layer / Surface layer • Surface layer / Intermediate layer / Core layer / Intermediate layer / Surface layer

[0070] (Surface layer) The outermost surface layer is preferably a layer containing, for example, linear low-density polyethylene as a resin component.

[0071] When the surface layer contains only linear low-density polyethylene as the resin component, the MFR (melt flow rate) of the linear low-density polyethylene is preferably 0.1 g / 10 min to 10 g / 10 min. In this specification, unless otherwise specified, the MFR is the value measured under JIS K7210-1:2014, Method A, 190°C, and a load of 2.16 kg.

[0072] When the surface layer contains linear low-density polyethylene and ethylene-α-olefin copolymer as resin components, the content of linear low-density polyethylene is, for example, 80% by mass or more and less than 100% by mass relative to 100% by mass of the resin components of the surface layer, and the content of ethylene-α-olefin copolymer is, for example, more than 0% by mass and 20% by mass or less relative to 100% by mass of the resin components of the surface layer, and the MFR of linear low-density polyethylene is, for example, 0.1 g / 10 min to 10 g / 10 min.

[0073] (Core layer) The core layer, which is the inner layer, is preferably a layer that contains, as a resin component, at least one selected from the group consisting of, for example, ultra-low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, low density polyethylene, linear low density polyethylene, and high density polyethylene.

[0074] When the core layer contains only ultra-low density polyethylene as a resin component, the MFR of ultra-low density polyethylene is preferably 0.2 g / 10 min to 7 g / 10 min. When the core layer contains ultra-low density polyethylene and ethylene-α-olefin copolymer as resin components, the content of ultra-low density polyethylene is preferably 60% by mass or more and less than 100% by mass relative to 100% by mass of the resin component of the core layer, and the content of ethylene-α-olefin copolymer is preferably greater than 0% by mass and 40% by mass or less relative to 100% by mass of the resin component of the core layer. When the core layer contains ultra-low density polyethylene and linear low density polyethylene as resin components, the content of ultra-low density polyethylene is preferably 60% by mass or more and less than 100% by mass relative to 100% by mass of the resin component of the core layer, and the content of linear low density polyethylene is preferably greater than 0% by mass and 40% by mass or less relative to 100% by mass of the resin component of the core layer.

[0075] When the core layer contains linear low-density polyethylene as the main component of the resin, the MFR of linear low-density polyethylene is preferably 0.2 g / 10 min to 7 g / 10 min. The term "contained as the main component" means containing 50% by mass or more of linear low-density polyethylene. When the core layer contains linear low-density polyethylene and low-density polyethylene having long-chain branches as the resin components, the content of linear low-density polyethylene is preferably 50% by mass or more and less than 100% by mass relative to 100% by mass of the resin components of the core layer, and the content of low-density polyethylene having long-chain branches is preferably more than 0% by mass and 50% by mass or less relative to 100% by mass of the resin components of the core layer. When the core layer contains linear low-density polyethylene and high-density polyethylene as resin components, the content of linear low-density polyethylene is preferably 50% by mass or more and less than 100% by mass relative to 100% by mass of the resin components of the core layer, and the content of high-density polyethylene is preferably greater than 0% by mass and 50% by mass or less relative to 100% by mass of the resin components of the core layer.

[0076] (Intermediate layer) The intermediate layer, which is the inner layer, is preferably a layer that contains, as a resin component, at least one selected from the group consisting of, for example, ultra-low density polyethylene, ethylene-α-olefin copolymer, low density polyethylene, linear low density polyethylene, and high density polyethylene.

[0077] When the intermediate layer contains only ultra-low density polyethylene as a resin component, the MFR of the ultra-low density polyethylene is preferably 0.2 g / 10 min to 7 g / 10 min. When the intermediate layer contains ultra-low density polyethylene and ethylene-α-olefin copolymer as resin components, the content of ultra-low density polyethylene is preferably 60% by mass or more and less than 100% by mass relative to 100% by mass of the resin component of the intermediate layer, and the content of ethylene-α-olefin copolymer is preferably more than 0% by mass and 40% by mass or less relative to 100% by mass of the resin component of the intermediate layer.

[0078] When the intermediate layer contains linear low-density polyethylene as the main component of the resin, the MFR of the linear low-density polyethylene is preferably 0.2 g / 10 min to 7 g / 10 min. When the intermediate layer contains linear low-density polyethylene and long-chain branched low-density polyethylene as the resin components, the content of linear low-density polyethylene is preferably 50% by mass or more and less than 100% by mass relative to 100% by mass of the resin components of the intermediate layer, and the content of long-chain branched low-density polyethylene is preferably more than 0% by mass and 50% by mass or less relative to 100% by mass of the resin components of the intermediate layer. When the intermediate layer contains linear low-density polyethylene and high-density polyethylene as the resin components, the content of linear low-density polyethylene is preferably 50% by mass or more and less than 100% by mass relative to 100% by mass of the resin components of the intermediate layer, and the content of high-density polyethylene is preferably more than 0% by mass and 50% by mass or less relative to 100% by mass of the resin components of the intermediate layer.

[0079] The resin components listed above for the surface layer, intermediate layer, and core layer can be freely replaced as long as the effects of the present invention are achieved. Therefore, the resin components listed above for the surface layer may be used in the intermediate layer and / or core layer, the resin components listed above for the intermediate layer may be used in the core layer and / or surface layer, and the resin components listed above for the core layer may be used in the surface layer and / or intermediate layer. Furthermore, for example, in a five-layer configuration of surface layer / intermediate layer / core layer / intermediate layer / surface layer, the two surface layers may be different from each other, and the two intermediate layers may be different from each other. Furthermore, as long as the effects of the present invention are achieved, the resin components listed above for the surface layer, intermediate layer, and core layer may be mixed and used in each layer.

[0080] It is preferable that the heat-shrinkable film has a large number of small through-holes. Furthermore, it is preferable that these small through-holes are concentrated at the top of the open container. By providing a large number of small through-holes in the heat-shrinkable film, the freshness of the soft fruits can be better preserved even when the heat-shrinkable film is used to wrap the entire area of ​​the container and the multiple soft fruits.

[0081] The planar shape of the small through-hole may be, for example, circular, polygonal, or a slit. A slit is a cut or narrow gap that penetrates the heat-shrinkable film, and may be a straight line, curve, L-shaped, or X-shaped.

[0082] The average diameter of the small through-holes is preferably 10 μm to 800 μm, more preferably 20 μm to 500 μm, and even more preferably 50 μm to 200 μm. In this case, the average diameter of the small through-holes is calculated from the opening area of ​​the small through-holes, assuming the small through-holes are perfect circles.

[0083] The heat-shrinkable film preferably comprises a layer containing a mold inhibitor and / or an anti-fogging agent.

[0084] Examples of antifungal agents include compounds such as organic sulfur, organic nitrogen sulfur, organic halogen, haloallyl sulfone, iodopropagyl, N-haloalkylthio, benzothiazole, nitrile, pyridine, 8-oxyquinoline, isothiazolin, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiadiazine, anilide, adamantane, dithiocarbamate, brominated indanone, benzyl bromacetate, and inorganic salts, as well as other known compounds. Antifungal agents can be used individually or in combination of two or more. For example, if the heat-shrinkable film has a surface layer, an intermediate layer, and a core layer, the antifungal agent may be included in any of these layers. The amount of the fungicide added to each layer (for example, each intermediate layer if there are two intermediate layers) is, for example, 0.1% to 10.0% by mass, for example, 0.1% to 9.0% by mass, for example, 0.1% to 8.0% by mass, for example, 0.1% to 7.0% by mass, for example, 0.1% to 6.0% by mass, for example, 0.1% to 5.0% by mass, based on the total mass of each layer. The amount of fungicide added to the surface layer, intermediate layer, and core layer may be the same or different.

[0085] Examples of antifogging agents include polyhydric alcohol partial fatty acid esters such as sorbitan fatty acid esters, glycerin fatty acid esters, glycerin fatty acid succinate esters, polyglycerin fatty acid esters, sorbitan-glycerin condensed fatty acid esters, sorbitan-diglycerin condensed fatty acid esters, pentaerythritol fatty acid esters, and dipentaerythritol fatty acid esters; ethylene oxide adducts such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyethylene glycol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene glycerin fatty acid esters; sorbitol derivatives obtained by adding propylene oxide and ethylene oxide to sorbitol and then esterifying it; amines and amides such as alkylamines, alkylamides, alkylethanolamines, and fatty acid diethanolamides, and their ethylene oxide adducts; nonionic surfactants such as polyalkylene glycols; cationic surfactants; anionic surfactants; and other known substances. Antifogging agents can be used individually or in combination of two or more. The amount of antifogging agent added is not particularly limited as long as the desired effect is substantially achieved. In the case of a heat-shrinkable film having a surface layer, an intermediate layer, and a core layer, the amount of anti-fogging agent added to the surface layer, intermediate layer, and core layer may be the same or different.

[0086] The heat-shrinkable film may contain additives to the extent that they do not impair its physical properties. Examples of such additives include antiblocking agents, lubricants, inorganic fillers, antioxidants, ultraviolet absorbers, antistatic agents, flame retardants, plasticizers, colorants, crystallization inhibitors, and crystallization accelerators.

[0087] The heat-shrinkable film preferably contains an antiblocking agent. Any known antiblocking agent can be used as long as it does not melt or decompose at the film formation temperature and can form protrusions on the film surface. The material and shape of the antiblocking agent can be anything, but it is preferable that it has good dispersibility and affinity with the resin components of each layer and has a refractive index close to that of the resin components of each layer. Examples of antiblocking agents include inorganic particles such as silica, alumina, calcium carbonate, silica-alumina, silica-zirconia, and zeolite; and synthetic resin particles such as silicone resin particles, silicone rubber particles, polyamide particles, crosslinked polymethyl methacrylate particles, and crosslinked polystyrene particles, or a mixture thereof.

[0088] The antiblocking agent may be added to all layers, but considering costs and the reduction in transparency, for example, if the heat-shrinkable film has a five-layer structure of surface layer / intermediate layer / core layer / intermediate layer / surface layer, it is preferable to add it to the surface layer and intermediate layer. Specifically, if the total amount of antiblocking agent added is 100% by mass, it is preferable to add a total of 80% to 100% by mass to the two intermediate layers, and a total of 0% to 20% by mass to the two surface layers. In addition, scrap resin generated during the manufacturing process of the heat-shrinkable film may be mixed into the core layer, as long as it does not hinder the effects of the present invention. Therefore, the core layer may contain additives (e.g., antiblocking agent) that were added when the surface layer and intermediate layer were manufactured.

[0089] The thickness of the heat-shrinkable film is preferably 10 μm to 24 μm, and more preferably 9.7 μm to 11.3 μm.

[0090] The present invention will be specifically described below using examples, but the present invention is not limited to these examples. In the examples, the equipment, conditions, etc., used for the manufacture of soft fruit packaging and various tests are as follows.

[0091] (1) Electron beam irradiation device: Curetron (registered trademark) EBC-200 manufactured by NHV Corporation (2) Heat shrinkage rate device: Precision constant temperature chamber DF611 manufactured by Yamato Scientific Co., Ltd. Conditions: Measured at 120°C in accordance with ASTM D 1204. (3) Heat shrinkage force device: Precision constant temperature chamber DF611 manufactured by Yamato Scientific Co., Ltd. Conditions: Measured at 100°C in accordance with ASTM D 2838. The measured value was adopted 10 seconds after the start of heating. (4) Tensile modulus device: Autograph AGS-X500N manufactured by Shimadzu Corporation Conditions: In accordance with JIS-Z1702. (5) Shrink wrapping machine: PROTO-A8000-G1 manufactured by Nippon Polystar Co., Ltd. (6) Storage device for soft fruit packaging: Commercial refrigerator EQD-252WM7 manufactured by Fukushima Industries Co., Ltd. (7) Vibration testing device: Transport packaging testing machine BF-50UT manufactured by IDEX Corporation (8) Electrical conductivity device: Portable electrical conductivity meter D-210PC and low electrical conductivity cell 3551-10D manufactured by Horiba, Ltd.

[0092] Furthermore, the abbreviations represent the following: LL1: Linear low-density polyethylene (single-site catalyst, density: 0.913 g / cm³) ３ MFR: 2.4 g / 10 min, melting peak temperature: 102°C, α-olefin: 1-hexene) LL2: Linear low-density polyethylene (multi-site catalyst, density: 0.920 g / cm³) ３ MFR: 0.5 g / 10 min, melting peak temperature: 122°C, α-olefin: 4-methyl-1-pentene) LL3: Linear low-density polyethylene (multi-site catalyst, density: 0.920 g / cm³) ３ MFR: 2.1 g / 10 min, Melting peak temperature: 122°C, α-olefin: 1-butene) VL1: Ultra-low density polyethylene (Density: 0.905 g / cm³) ３ MFR: 0.8 g / 10 min, Melting peak temperature: 96°C, α-olefin: 1-octene) HD1: High-density polyethylene (density 0.968 g / cm³) ３, MFR: 5.2 g / 10 min, melting peak temperature: 115°C) OPP film: Biaxially oriented polypropylene film (conventional overlay film (non-heat shrinkable film), thickness: 24.4 μm) Film 2: Polyethylene crosslinked film {thickness: 11.0 μm, heat shrinkage rate (120°C): 75.0% (MD), 70.5% (TD), heat shrinkage force (120°C): 0.35 N / cm (MD), 0.22 N / cm (TD), tensile modulus: 0.28 GPa (MD), 0.27 GPa (TD)} AFA1: Antifogging agent (glycerin fatty acid ester) AFA2: Antifogging agent (glycerin fatty acid ester) AOX: Antioxidant (Irgaphos 168) ABA: Antiblocking agent [polymethyl methacrylate (PMMA) spherical particles, average particle size 2 μm] MB1: A masterbatch pellet obtained by melt-kneading 95 parts by mass of linear low-density polyethylene and 5 parts by mass of AOX, and then granulating it. MB2: A masterbatch pellet obtained by melt-kneading 90 parts by mass of linear low-density polyethylene and 10 parts by mass of ABA, and then granulating it.

[0093] (Manufacturing of polyethylene crosslinked heat shrink wrap film (film 1)) The resins shown in Table 1 were melted and kneaded using three extruders, and the molten resin, consisting of five layers: two surface layers, two intermediate layers, and one core layer, was extruded from an annular die into a tube shape. It was rapidly cooled with water to obtain an unstretched film. At this time, the ratio of the thickness of each layer was 1 / 1 / 5 / 1 / 1. The obtained tubular unstretched film was irradiated with an electron beam from one side using an electron beam irradiation device set to an acceleration voltage of 260 kV and an absorbed dose of 110 kGy, and then the electron beam was similarly irradiated from the opposite side to perform crosslinking treatment. After that, the tubular unstretched film was led to a tubular biaxial stretching device. The surface temperature of the unstretched film was heated with an annular infrared heater until it reached the melting point of the resin, and pressurized air was introduced into the tube to form bubbles. A polyethylene crosslinked heat-shrinkable wrap film (hereinafter also referred to as Film 1) with a thickness of 10.2 μm was obtained by stretching in the MD (longitudinal direction) using the peripheral speed ratio of a low-speed nip roll and a high-speed nip roll, and then stretching in the TD (width direction) with pressurized air, folding while cooling with cold air applied to the bottom of the bubble using an air ring, and then performing a 4% relaxation heat treatment on a heated roll at 85°C. The heat shrinkage rate and heat shrinkage force of the obtained Film 1 were measured at 80°C, 100°C, and 120°C. Furthermore, the tensile modulus was measured. The results are shown in Table 1.

[0094]

[0095] [Example 1] Strawberries (Amaou® Fukuoka S6, harvested in winter) were packed flat in a single layer in a polyethylene terephthalate container (approximately 30g / piece, 270g standard size), and then wrapped in heat-shrinkable film. Film 1 was used for the wrapping. Film 1 was used to cover the entire circumference of the strawberries and the container, and then heat treatment was performed for 3 seconds in a shrink tunnel set to 137°C to heat-shrink Film 1, obtaining the soft fruit packaging of Example 1 as shown in Figures 1, 2, and 3.

[0096] [Example 2] Strawberries (Amaou® Fukuoka S6, harvested in winter) were packed in two layers (approximately 20g / piece, 270g standard) in a polyethylene terephthalate container and wrapped in heat-shrinkable film. Film 1 was used for wrapping. Film 1 was used to cover the entire circumference of the strawberries and container, and then heat treatment was performed for 3 seconds in a shrink tunnel set to 137°C to heat-shrink Film 1, thereby obtaining the soft fruit packaging of Example 2 as shown in Figures 4, 5, and 6.

[0097] [Example 3] The soft fruit packaging of Example 3 was obtained by performing the same procedure as in Example 1, except that a foamed polyurethane sheet for buffering was placed between the polyethylene terephthalate container and the strawberries (a cross-sectional view of the soft fruit packaging of Example 3 is shown in Figure 7).

[0098] [Example 4] Instead of covering the entire perimeter of the strawberries and container with film 1 and heat-treating them, an OPP film was placed on top (packaging so as to cover the top of the opening of the container), and the same procedure as in producing the soft fruit packaging of Example 1 was performed to obtain the soft fruit packaging of Example 4.

[0099] [Example 5] The soft fruit packaging of Example 5 was obtained by performing the same procedure as for manufacturing the soft fruit packaging of Example 2, except that instead of covering the entire area of ​​the strawberries and container with film 1 and heat-treating it, an OPP film was placed on top.

[0100] [Example 6] The soft fruit packaging of Example 6 was obtained by performing the same procedure as in Example 4 for producing the soft fruit packaging, except that a foamed polyurethane sheet for buffering was placed between the polyethylene terephthalate container and the strawberries.

[0101] [Example 7] In the container described in Figure 20 of Japanese Patent Publication No. 2011-102152 (hereinafter also referred to as a suspended container), 12 strawberries (Amaou® Fukuoka S6, harvested in winter, weight of strawberries approximately 35g / piece) were packed into 400g to 450g containers (12-piece specification), and the lid was placed over them. The packaging for this suspended container was the soft fruit packaging of Example 7.

[0102] [Example 8] The soft fruit packaging of Example 8 was obtained by performing the same procedure as in Example 1, except that film 2 was used instead of film 1. When film 2 was heat-shrinked, several strawberries were crushed, so the vibration test described later was not performed.

[0103] [Example 9] A foamed polyethylene buffer tray (8-grain specification) having a soft fruit storage section was placed inside a polypropylene container, and strawberries (Koiminori® registered trademark, harvested in winter) were placed in the soft fruit storage section (approximately 25g / piece, 180g standard), and the container was wrapped with heat-shrinkable film. Film 1 was used for the wrapping. Film 1 was used to cover the entire area around the strawberries and the container, and then heat treatment was performed for 3 seconds in a shrink tunnel set to 137°C to heat-shrink the film 1 and obtain the soft fruit packaging of Example 9.

[0104] [Example 10] The soft fruit packaging of Example 10 was obtained by performing the same procedure as for producing the soft fruit packaging of Example 9, except that instead of covering the entire area of ​​the strawberries and container with film 1 and heat-treating it, an OPP film was placed on top.

[0105] [Example 11] The soft fruit packaging of Example 11 was obtained by performing the same procedure as in Example 1, except that strawberries (Koiminori®, harvested in winter, weighing approximately 25g / piece) were used instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as soft fruit.

[0106] [Example 12] The soft fruit packaging of Example 12 was obtained by performing the same procedure as in Example 4, except that strawberries (Koiminori®, harvested in winter, weighing approximately 25g / piece) were used instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as soft fruit.

[0107] [Example 13] Instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as soft fruit, strawberries (Koiminori®, harvested in winter, weighing approximately 25g / piece) were used, a suspended container with a capacity of 15 pieces was used, and 15 pieces of the aforementioned strawberries were packed into each container. Except for these differences, the same procedure as in the production of the soft fruit packaging in Example 7 was followed to obtain the soft fruit packaging of Example 13.

[0108] [Example 14] In a suspended container, 11 strawberries (Koiminori®, harvested in winter, approximately 25g / strawberry) were packed into 220g to 280g standard containers (11-berry specification) and wrapped in heat-shrinkable film. Film 1 was used for wrapping. Film 1 was used to cover the entire circumference of the strawberries and container, and then heat treatment was performed for 3 seconds in a shrink tunnel set to 137°C to heat-shrink Film 1 and obtain the soft fruit packaging of Example 14.

[0109] [Example 15] The soft fruit packaging of Example 15 was obtained by performing the same procedure as in Example 2, except that strawberries (Koiminori®, harvested in winter, weighing approximately 25g / piece) were used instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as soft fruit.

[0110] [Example 16] The soft fruit packaging of Example 16 was obtained by performing the same procedure as in Example 5, except that strawberries (Koiminori®, harvested in winter, weighing approximately 25g / piece) were used instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as soft fruit.

[0111] <Vibration Test for Electrical Conductivity Measurement> For the soft fruit packaging of Examples 1, 2, 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, and 16, which will be the subject of the electrical conductivity measurement described later, the soft fruit packaging was stored in a refrigerator at 4°C for two days after manufacturing until the day of the vibration test. The vibration test was conducted with reference to the vibration test method described in Reference 1 below. Reference 1. Nakamura et al., et al., "Effects of Different Packaging Conditions on Strawberry Fruit Damage", (2008) Agricultural Facilities, 39, pp. 1-8. Soft fruit packaging of Examples 1, 3, 6, 9, and 10 was packed two packs per cardboard box. Soft fruit packaging of Examples 2 and 5 was packed four packs per cardboard box. Soft fruit packaging of Examples 7, 13, and 14 was packed one pack per cardboard box. In addition, two packs each of Examples 11 and 15 were packed, for a total of four packs per cardboard box. Furthermore, two packs each of Example 12 and Example 16 were packed into each cardboard box, for a total of four packs. Assuming resonance, a sinusoidal uniform sweep vibration test was performed for 30 minutes on one cardboard box containing soft fruit packaging for Examples 1, 2, 3, 5, 6, 7, 9, 10, 13, and 14, as well as Examples 11 and 15, and Examples 12 and 16, using a vibration testing device. The conditions for the vibration test are shown below. (Conditions for vibration test) Lower frequency limit: 10 Hz, Upper frequency limit: 40 Hz, Sweep time: 10 minutes, Number of sweeps: 3, Vibration direction: Simultaneous vibration of three axes: X-axis (horizontal), Y-axis (horizontal), Z-axis (vertical), Gravitational acceleration: 0G to 3G (m / s²) ２ (Dependent on frequency).

[0112] <Evaluation of the degree of damage to soft fruit due to vibration (measurement of electrical conductivity)> In evaluating the degree of damage to strawberries due to vibration, the electrical conductivity of the strawberry immersion solution was evaluated as the degree of damage, referring to Reference 2 below. Reference 2. Jiang et al., et al., "Electrical Conductivity Evaluation of Postharvest Strawberry Damage", (2001) J. Food Sci., 66, pp. 1392-1395. The electrical conductivity was measured on the same day that the vibration test described above was conducted. For the soft fruit packaging of Examples 1, 2, 3, 5, 6, 7, 9, 10, 13, and 14, as well as Examples 11 and 15, and Examples 12 and 16, after the vibration test described above, all the strawberries in one pack were placed in six times the total weight of the strawberries in pure water (electrical conductivity 1.0 μS / cm), and the electrical conductivity of the immersion solution was measured after 30 minutes. During the 30 minutes leading up to the measurement, the immersion solution was gently stirred with a ladle to avoid damaging the strawberries as much as possible. The results are shown in Figures 9 and 17, etc.

[0113] <Vibration Test for Sensory Evaluation> For the soft fruit packaging examples 1, 2, 3, 5, 6, and 7, which will be the subject of sensory evaluation described later, vibration tests were conducted immediately after their manufacture. The method and conditions of the vibration tests were as described in <Vibration Test for Electrical Conductivity Measurement> above. These soft fruit packaging materials used for sensory evaluation were stored in a refrigerator at 12°C for two days after the vibration tests.

[0114] <Evaluation of Damage to Soft Fruit Due to Vibration (Sensory Evaluation)> Strawberries were removed from soft fruit packages of Examples 1, 2, 3, 5, 6, and 7, which had been stored in a refrigerator at 12°C for two days after the vibration test, and the degree of damage observed on the surface of the strawberries was investigated visually. The degree of damage was calculated for each pack by visually counting the number of achenes including the damaged area for each strawberry, referring to Reference 1, and dividing by the total number of achenes. Regarding the total number of achenes, the average total number of achenes (AN) and the average weight of one fruit (FW (g)) per pack were investigated from the analysis of 25 packs, and it was found that AN = 43.415 × FW ０．６０８９ (R ２Since a value of 0.8808 was obtained, the value calculated from the average weight of one fruit per pack was applied. Based on Reference 3, damage was defined as mold, rot, occre (damage involving deformation of strawberries due to collisions between strawberries or between strawberries and the container), and abrasion (damage caused by friction between strawberries or the container). The results are shown in Figure 10. Reference 3. Minori Endo (Hikawa), Kazuyoshi Sone, "Evaluation of the damage reduction effect of new packaging containers and MA packaging on strawberry fruit in air and sea transport" (2017), Horticultural Science Research, Vol. 16, pp. 95-104.

[0115] As shown in Figure 9, the electrical conductivity of the strawberry immersion solution in Example 1, which was packaged with heat-shrinkable film, was approximately 20.2 μS / cm. In Example 6, which was packaged with OPP film (conventional overlay film (non-heat-shrinkable film)) covering the top of the container opening and had a buffer foamed polyurethane sheet laid on top, the electrical conductivity of the strawberry immersion solution was approximately 15.7 μS / cm. Compared to Example 1, the results for the electrical conductivity of the soft fruit package in Example 6 did not show a statistically significant difference at the 5% level in the Mann-Whitney U test. Therefore, the degree of damage to the strawberries in the soft fruit package packaged with heat-shrinkable film without a buffer foamed polyurethane sheet was about the same as the degree of damage to the strawberries in the soft fruit package packaged with OPP film covering the top of the container opening and had a buffer foamed polyurethane sheet laid on top. Furthermore, in Example 3, the soft fruit packaging, which was wrapped in heat-shrinkable film and lined with a foamed polyurethane sheet for cushioning, had an electrical conductivity of approximately 6.5 μS / cm for the strawberry immersion solution. Also, the reduction in electrical conductivity of Example 3 compared to the electrical conductivity of Example 6 was approximately 59%. Therefore, wrapping with heat-shrinkable film was able to reduce the degree of damage to the strawberries. Also, as shown in Figure 9, in Example 5, the soft fruit packaging, which was wrapped with OPP film covering the top of the container opening, had an electrical conductivity of approximately 23.6 μS / cm for the strawberry immersion solution. On the other hand, in Example 2, the soft fruit packaging, which was wrapped in heat-shrinkable film, had an electrical conductivity of approximately 6.9 μS / cm for the strawberry immersion solution. Also, the reduction in electrical conductivity of Example 2 compared to the electrical conductivity of Example 5 was approximately 71%. The results for the electrical conductivity of the soft fruit packaging between Example 3 and Example 6, and between Example 2 and Example 5, showed statistically significant differences at the 1% and 5% levels, respectively, as calculated by the Mann-Whitney U test. Therefore, the degree of damage to the strawberries was reduced in both single-layer and double-layer packaging. On the other hand, in Example 7, where the soft fruit packaging was packed in a suspended container, the electrical conductivity of the strawberry immersion liquid was approximately 7.9 μS / cm.Therefore, the soft fruit packaging in Examples 2 and 3, in which multiple strawberries were packed in a single layer or in two layers to meet specific conditions and wrapped with heat-shrinkable film covering the entire area around the container and multiple strawberries, reduced the degree of damage to the strawberries to the same extent as the soft fruit packaging in Example 7, which used a suspended container. Furthermore, as shown in Figure 17, the soft fruit packaging in Example 9, which was wrapped with heat-shrinkable film and had a buffer tray, had an electrical conductivity of approximately 3.7 μS / cm for the strawberry immersion solution. Furthermore, as shown in Figure 17, the soft fruit packaging in Example 10, which was wrapped with OPP film covering the top of the container opening and had a buffer tray, had an electrical conductivity of approximately 10.9 μS / cm for the strawberry immersion solution. The reduction rate of the electrical conductivity in Example 9 compared to the electrical conductivity of Example 10 was 66%. Furthermore, in Example 13, which was created by changing the type of strawberry and the number of recesses in the soft fruit storage section from Example 7, the electrical conductivity of the strawberry immersion solution was approximately 9.4 μS / cm. In addition, in Example 14, which was created by changing the type of strawberry and the number of recesses in the soft fruit storage section from Example 7 and also wrapped in heat-shrinkable film, the electrical conductivity of the strawberry immersion solution was approximately 7.5 μS / cm. The results for the electrical conductivity of the soft fruit packaging between Example 9 and Example 10, and between Example 9 and Example 13, showed statistically significant differences at the 1% and 5% levels, respectively, using the Mann-Whitney U test. Therefore, the soft fruit packaging of Example 9, which includes a container with a buffer tray in which a soft fruit storage section is formed and placed within the storage space, and is wrapped with heat-shrinkable film covering the entire perimeter of the container, and which meets specific conditions, showed a reduced degree of damage to the strawberries compared to the soft fruit packaging of Example 10, which was wrapped with OPP film covering the top of the container opening instead of heat-shrinkable film. Furthermore, the soft fruit packaging of Example 9 showed an even greater reduction in the degree of damage to the strawberries compared to the soft fruit packaging of Example 13, which used a suspended container. In addition, the soft fruit packaging of Examples 11 and 15, which were obtained by changing the type of strawberry from the soft fruit packaging of Examples 1 and 2, were placed in a container (cardboard box), and after a vibration test, the electrical conductivity of the strawberry immersion liquid was approximately 9.3 μS / cm.Furthermore, after placing the soft fruit packaging materials of Examples 12 and 16, which were obtained by changing the type of strawberry from the soft fruit packaging materials of Examples 4 and 5, into a container (cardboard box) and conducting a vibration test, the electrical conductivity of the strawberry immersion solution was approximately 19.1 μS / cm. In addition, the results for the electrical conductivity of the soft fruit packaging materials between Examples 11 and 15 and Examples 12 and 16 showed a statistically significant difference at the 5% level using the Mann-Whitney U test.

[0116] As shown in Figure 10, the soft fruit packaging in Example 1, which was wrapped in heat-shrinkable film, showed damage to approximately 21.7% of the strawberry surface area. In Example 6, the soft fruit packaging, which was wrapped with OPP film covering the top of the container opening and also had a cushioning foamed polyurethane sheet laid down, showed damage to approximately 24.4% of the strawberry surface area. Compared to Example 1, the sensory evaluation results for the percentage of damaged strawberry area in Example 6 did not show a statistically significant difference at the 5% level in the Mann-Whitney U test. Therefore, the degree of damage to the strawberries in the soft fruit packaging wrapped in heat-shrinkable film without a cushioning foamed polyurethane sheet was similar to that of the soft fruit packaging wrapped with OPP film covering the top of the container opening and also had a cushioning foamed polyurethane sheet laid down. Furthermore, in Example 3, the soft fruit packaging, which was wrapped in heat-shrinkable film and also had a cushioning foamed polyurethane sheet laid down, showed damage to approximately 12.7% of the strawberry surface area. Therefore, packaging with heat-shrinkable film reduced the degree of damage to the strawberries. Furthermore, as shown in Figure 10, in Example 5, where the soft fruit packaging was wrapped with OPP film covering the top of the container opening, damage was observed on approximately 46.6% of the strawberry surface area. On the other hand, in Example 2, where the soft fruit packaging was wrapped with heat-shrinkable film, damage was observed on approximately 15.4% of the strawberry surface area. The percentage of damaged strawberry area, as determined by sensory evaluation of the soft fruit packaging between Example 3 and Example 6, and between Example 2 and Example 5, showed statistically significant differences at the 5% level using the Mann-Whitney U test. Therefore, the degree of damage to the strawberries was reduced in both single-layer and double-layer packaging. Conversely, in Example 7, where the soft fruit packaging was packed in a suspended container, the damage area percentage was approximately 13.8%. Therefore, the soft fruit packaging in Examples 2 and 3, in which multiple strawberries were packed in a single layer or in two layers to meet specific conditions and wrapped with heat-shrinkable film covering the entire surface of the multiple strawberries and the container, reduced the degree of damage to the strawberries to the same extent as the soft fruit packaging in Example 7, which used a suspended container.Furthermore, electrical conductivity and the degree of fruit damage as determined by sensory evaluation showed similar trends.

[0117] This invention provides a novel soft fruit packaging material that prevents damage to soft fruits caused by vibration during transportation.

[0118] 1 Soft fruit packaging 2 Container 3 Container bottom 4 Container side wall 4A Upper end of container side wall 5 Storage space 6 Soft fruit 7 Heat shrinkable film 8 Foamed synthetic resin sheet 9 Virtual flat surface 10 Cushioning tray 11 Soft fruit storage section 11A Recess 11B Surface in the soft fruit storage section opposite to the surface in contact with multiple soft fruits 22 Container 23 Container bottom 24 Container side wall 24A Upper end of container side wall 111 Soft fruit storage section 111A Recess 111B Surface in the soft fruit storage section opposite to the surface in contact with multiple soft fruits

Claims

1. A soft fruit package comprising a container having a flat, substantially rectangular container bottom and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a plurality of soft fruits stored in a single layer in the storage space surrounded by the container side walls, and a heat shrinkable film that covers the plurality of soft fruits and the entire periphery of the container, wherein the plurality of soft fruits satisfy the following conditions: Condition (1): The plurality of soft fruits are in contact with at least one of each other. Condition (2): At least one soft fruit is in contact with each of the four container side walls forming the container. Condition (3): The plurality of soft fruits are in contact with the heat shrinkable film. Condition (4): The plurality of soft fruits are in contact with the container bottom.

2. A soft fruit package comprising a container having a flat, substantially rectangular container bottom and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a plurality of soft fruits stored in two layers, upper and lower, in the storage space surrounded by the container side walls, and a heat shrinkable film that covers the plurality of soft fruits and the entire periphery of the container, wherein the plurality of soft fruits satisfy the following conditions: Condition (1): The plurality of soft fruits are in contact with at least one of each other. Condition (2): At least one soft fruit is in contact with each of the four container side walls forming the container. Condition (3'): Of the plurality of soft fruits, the soft fruits stored in the upper layer are in contact with the heat shrinkable film, and the soft fruits stored in the lower layer are in contact with the soft fruits stored in the upper layer. Condition (4'): Of the plurality of soft fruits, the soft fruits stored in the lower layer are in contact with the container bottom.

3. The soft fruit packaging according to claim 1 or claim 2, wherein the soft fruit is a strawberry.

4. The soft fruit packaging according to claim 1 or claim 2, wherein the heat-shrinkable film is provided with a number of small through-holes, and these small through-holes are concentrated at the top of the open container.

5. The soft fruit packaging according to claim 1 or 2, wherein the heat-shrinkable film comprises a layer containing a fungicide and / or an anti-fogging agent.

6. The soft fruit packaging according to claim 1 or 2, wherein the heat shrinkable film has a heat shrinkage rate of 58% to 67% in both the MD (longitudinal direction) and TD (width direction) at 120°C, a heat shrinkage force of 0.25 N / cm or less in the MD direction at 120°C, a heat shrinkage force of 0.22 N / cm or less in the TD direction at 120°C, a tensile modulus of elasticity of 0.25 GPa to 0.29 GPa in the MD direction, and a tensile modulus of elasticity of 0.25 GPa to 0.27 GPa in the TD direction.

7. The soft fruit packaging according to claim 1 or claim 2, wherein the heat-shrinkable film contains a plant-derived polyethylene resin.

8. The soft fruit packaging according to claim 1 or 2, wherein, with respect to the soft fruit in the soft fruit packaging, the reduction rate of the electrical conductivity of the aqueous solution in which the soft fruit was immersed after a vibration test, measured by the evaluation method described below, is 20% or more compared to the soft fruit packaging according to claim 1 or 2, in which the soft fruit packaging is packaged with a non-heat-shrinkable film instead of a heat-shrinkable film so as to cover at least the upper part of the opening of the container. [Electrical conductivity of aqueous solution in which soft fruit was immersed after a vibration test] (1) Vibration test A sinusoidal uniform sweep vibration test is performed for 30 minutes on a container containing one or more soft fruit packagings using a vibration test apparatus under the following conditions. (Conditions for vibration test) Lower frequency limit: 10 Hz, Upper frequency limit: 40 Hz, Sweep time: 10 minutes, Number of sweeps: 3, Vibration direction: Simultaneous of three axes: X axis (horizontal direction), Y axis (horizontal direction), Z axis (vertical direction), Gravitational acceleration: 0 G to 3 G (m / s²) ２ (Dependent on frequency). (2) Electrical conductivity measurement After the vibration test, the soft fruits removed from the container are placed in six times the total weight of the soft fruits in pure water (electrical conductivity 1.0 μS / cm), the aqueous solution in which the soft fruits are immersed is stirred for 30 minutes, and the electrical conductivity measured using an electrical conductivity meter is taken as the electrical conductivity of the aqueous solution in which the soft fruits were immersed after the vibration test.

9. A soft fruit package comprising a container having a roughly rectangular container bottom and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top; a buffer tray disposed inside the container and having a soft fruit storage section provided with a plurality of recesses for storing a plurality of soft fruits; a plurality of soft fruits stored in the soft fruit storage section; and a heat shrink film that covers the plurality of soft fruits and the entire periphery of the container, wherein the soft fruit package satisfies the following conditions: Condition (a): With respect to the soft fruit storage section of the buffer tray, the side opposite to the side that contacts the plurality of soft fruits is in contact with the container bottom. Condition (b): The plurality of soft fruits are in contact with the heat shrink film.

10. A soft fruit package comprising a container having a substantially rectangular container bottom with a soft fruit storage section having multiple recesses for storing multiple soft fruits, and four container side walls extending upward from the entire periphery of the container bottom and forming a container with an open top, a plurality of soft fruits stored in the soft fruit storage section, and a heat shrink film that covers the plurality of soft fruits and the entire periphery of the container, wherein the soft fruit package satisfies the following conditions: Condition (a): The plurality of soft fruits are in contact with the heat shrink film.

11. The soft fruit packaging according to claim 9 or claim 10, wherein the soft fruit is a strawberry.

12. The soft fruit packaging according to claim 9 or claim 10, wherein the heat-shrinkable film is provided with a number of small through-holes, and these small through-holes are concentrated at the top of the open container.

13. The soft fruit packaging according to claim 9 or 10, wherein the heat shrinkable film comprises a layer containing a fungicide and / or an antifogging agent.

14. The soft fruit packaging according to claim 9 or claim 10, wherein the heat shrinkable film has a heat shrinkage rate of 58% to 67% in both the MD (longitudinal direction) and TD (width direction) at 120°C, a heat shrinkage force of 0.25 N / cm or less in the MD direction, a heat shrinkage force of 0.22 N / cm or less in the TD direction at 120°C, a tensile modulus of elasticity of 0.25 GPa to 0.29 GPa in the MD direction, and a tensile modulus of elasticity of 0.25 GPa to 0.27 GPa in the TD direction.

15. The soft fruit packaging according to claim 9 or claim 10, wherein the heat-shrinkable film contains a plant-derived polyethylene resin.

16. The soft fruit packaging according to claim 9, wherein the cushioning tray is made of a foamed synthetic resin sheet, and the foamed synthetic resin sheet is made of at least one foamed synthetic resin selected from the group consisting of foamed polystyrene, foamed polyethylene, foamed polypropylene, and foamed polyurethane.

17. The soft fruit packaging according to claim 9 or claim 10, wherein, with respect to the soft fruit in the soft fruit packaging, the reduction rate of the electrical conductivity of the aqueous solution in which the soft fruit was immersed after a vibration test measured by the evaluation method described below is 20% or more compared to the soft fruit packaging according to claim 9 or claim 10, in which the soft fruit packaging is packaged with a non-heat-shrinkable film instead of a heat-shrinkable film so as to cover at least the upper part of the opening of the container. [Electrical conductivity of aqueous solution in which soft fruit was immersed after vibration test] (1) Vibration test Using a vibration test apparatus, a sinusoidal uniform sweep vibration test shall be performed for 30 minutes on a container containing one or more soft fruit packages under the following conditions. (Conditions for vibration test) Lower frequency limit: 10 Hz, Upper frequency limit: 40 Hz, Sweep time: 10 minutes, Number of sweeps: 3, Vibration direction: Simultaneous of three axes: X axis (horizontal), Y axis (horizontal), Z axis (vertical), Gravitational acceleration: 0G to 3G (m / s²) ２ (Dependent on frequency). (2) Electrical conductivity measurement After the vibration test, the soft fruits removed from the container are placed in six times the total weight of the soft fruits in pure water (electrical conductivity 1.0 μS / cm), the aqueous solution in which the soft fruits are immersed is stirred for 30 minutes, and the electrical conductivity measured using an electrical conductivity meter is taken as the electrical conductivity of the aqueous solution in which the soft fruits were immersed after the vibration test.

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