Soft fruit packaging

Abstract

To provide a new packaging material for soft fruits that prevents damage to soft fruits due to vibration during transportation. [Solution] A 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 single layer or in two layers, 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 specific conditions. A soft fruit packaging comprising a container having a container bottom with a soft fruit storage section formed therein, or a container in which a buffer tray with a soft fruit storage section formed therein is arranged in the storage space, 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 plurality of soft fruits satisfy specific conditions.

Description

[Technical Field]

[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. [Background technology]

[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 that has fruit storage recesses formed in a thin thermoplastic synthetic resin sheet for individually storing relatively fragile fruits such as strawberries (Patent Document 1). Furthermore, a packaging system has been proposed that includes a container X containing an inner container for individually storing fruits (Patent Document 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2011-102152 [Patent Document 2] Japanese Patent Publication No. 2021-75310 [Overview of the Initiative] [Problems that the invention aims to solve]

[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. [Means for solving the problem]

[0007] As a result of diligent research to solve the above problems, the inventors have found that when 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 when a package is wrapped in heat-shrinkable film to cover the entire perimeter of the container and multiple soft fruits, damage to the soft fruits due to vibration can be prevented. Furthermore, the inventors have discovered that a container having a container bottom with a soft fruit storage section formed therein, or a container in which a buffer tray with a soft fruit storage section formed therein is arranged within the storage space, and which is wrapped with a heat-shrinkable film to cover the entire circumference of the container, and which satisfies certain conditions, can prevent damage to 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 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 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): Multiple soft fruits are in contact with at least one other. Condition (2): At least one soft fruit is in contact with each of the four side walls forming the container. Condition (3): Multiple soft fruits are in contact with the heat-shrinkable film. Condition (4): Multiple soft fruits are in contact with the bottom of the container. [2] A container having a substantially rectangular container bottom in a flat shape and four container side wall portions extending upward from the entire peripheral edge of the container bottom and forming a container with an open upper portion, a plurality of soft fruits stored in a vertically double-layered manner in a storage space surrounded by the container side wall portions, and a heat-shrinkable film for packaging so as to cover the plurality of soft fruits and the entire periphery of the container. The plurality of soft fruits satisfy the following conditions: Condition (1): At least one of the plurality of soft fruits is in contact with each other. Condition (2): At least one soft fruit is in contact with each of the four container side wall portions forming the container. Condition (3’): Among 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’): Among the plurality of soft fruits, the soft fruits stored in the lower layer are in contact with the container bottom. [3] The soft fruit package according to [1] or [2], wherein the soft fruit is a strawberry. [4] The soft fruit package according to [1] or [2], wherein a large number of small through-holes are provided in the heat-shrinkable film, and the small through-holes are concentrated in the upper part of the open container. [5] The soft fruit package according to [1] or [2], wherein the heat-shrinkable film includes a layer containing a mildew-proof agent and / or an anti-fog agent. [6] The heat-shrinkable film The heat shrinkage rates in the MD (longitudinal direction) and TD (width direction) at 120 °C are both 58% - 67%, the heat shrinkage force in the MD at 120 °C is 0.25 N / cm or less, and the heat shrinkage force in the TD at 120 °C is 0.22 N / cm or less. The soft fruit package according to [1] or [2], wherein the tensile elastic modulus in the MD is 0.25 GPa - 0.29 GPa, and the tensile elastic modulus in the TD is 0.25 GPa - 0.27 GPa. [7] The soft fruit package according to [1] or [2], wherein the heat-shrinkable film contains a plant-derived polyethylene-based resin. [8] For the soft fruits in the soft fruit package, regarding the electrical conductivity of the aqueous solution in which the soft fruits after the vibration test measured by the following evaluation method are immersed, compared with the soft fruit package in which at least the upper part of the opening of the container is covered with a non-thermal shrink film instead of the thermal shrink film in the soft fruit package described in [1] or [2], the reduction rate of the electrical conductivity is 20% or more, the soft fruit package described in [1] or [2]. [Electrical conductivity of the aqueous solution in which the soft fruits after the vibration test are immersed] (1) Vibration test Using a vibration test device, a sine wave uniform sweep vibration test is performed for 30 minutes on a container containing one or more soft fruit packages under the following conditions. (Vibration test conditions) Lower limit frequency: 10 Hz, upper limit frequency: 40 Hz, sweep time: 10 minutes, sweep number: 3 times, vibration direction: three axes of X-axis (horizontal direction), Y-axis (horizontal direction), and Z-axis (vertical direction) simultaneously, gravitational acceleration: 0G~3G (m / s 2 )(Depending on frequency). (2) Electrical conductivity measurement After the vibration test, a plurality of soft fruits removed from the container are put into pure water (electrical conductivity 1.0 μS / cm) six times the total weight of the plurality of soft fruits, and the aqueous solution in which the soft fruits are immersed is stirred for 30 minutes. Then, the electrical conductivity measured using an electrical conductivity meter for the aqueous solution is used as the electrical conductivity of the aqueous solution in which the soft fruits after the vibration test are immersed. [9] A soft fruit package including a container having a substantially rectangular container bottom and four container side wall portions extending upward from the entire peripheral edge of the container bottom and forming an upper-open container, a buffer tray having a soft fruit storage portion disposed therein and provided with a plurality of recesses for storing a plurality of soft fruits, a plurality of soft fruits stored in the soft fruit storage portion, and a thermal shrink film for wrapping the entire periphery of the plurality of soft fruits and the container, satisfying the following conditions, the soft fruit package. Condition (a): Regarding the soft fruit storage portion of the buffer tray, the surface opposite to the surface in contact with the plurality of soft fruits is in contact with the container bottom. Condition (i): The plurality of soft fruits are in contact with the thermal 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 shrinkable 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): Multiple soft fruits are in contact with a heat-shrinkable film.

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

[10] , wherein the soft fruit is a strawberry.

[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 a fungicide and / or an antifogging agent.

[14] The aforementioned heat-shrinkable film is At 120°C, the thermal shrinkage rates in the MD (longitudinal direction) and TD (width direction) are both 58% to 67%, the thermal shrinkage force in the MD at 120°C is 0.25 N / cm or less, and the thermal shrinkage force in the TD at 120°C is 0.22 N / cm or less. The soft fruit packaging according to [9] or

[10] , wherein the tensile modulus of MD is 0.25 GPa to 0.29 GPa and the tensile modulus of TD is 0.25 GPa to 0.27 GPa.

[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 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 described in [9] or

[10] , wherein, with respect to the soft fruit in the soft fruit packaging, 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 reduced by 20% or more compared to the soft fruit packaging described in [9] or

[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 container opening. [Electrical conductivity of aqueous solution in which soft fruit was immersed after vibration testing] (1) Vibration test Using a vibration testing apparatus, a sinusoidal uniform sweep vibration test is performed for 30 minutes on a container containing one or more soft fruit packages under the following conditions. (Conditions for vibration testing) Lower frequency limit: 10Hz, Upper frequency limit: 40Hz, Sweep time: 10 minutes, Number of sweeps: 3, Vibration direction: Simultaneous movement of 3 axes: X-axis (horizontal), Y-axis (horizontal), Z-axis (vertical), Gravitational acceleration: 0G~3G (m / s²) 2 (Dependent on frequency). (2) Measurement of electrical conductivity After the vibration test, the soft fruits removed from the container were placed in a solution of pure water (electrical conductivity 1.0 μS / cm) six times the total weight of the soft fruits. The solution containing the soft fruits was stirred for 30 minutes, and the electrical conductivity of the solution measured using an electrical conductivity meter was defined as the electrical conductivity of the solution containing the soft fruits after the vibration test. [Effects of the Invention]

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

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

[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 comprises a flat, substantially rectangular container bottom and a structure extending upward from the entire periphery of the container bottom, with an open top. The present invention relates to a soft fruit packaging comprising a container having four container side walls forming an opening, 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 perimeter of the container, wherein the plurality of soft fruits satisfy the following conditions. Condition (1): Multiple soft fruits are in contact with at least one other. Condition (2): At least one soft fruit is in contact with each of the four side walls forming the container. Condition (3): Multiple soft fruits are in contact with the heat-shrinkable film. Condition (4): Multiple soft fruits are in contact with the bottom of the container.

[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 (packed horizontally to the bottom of the container without stacking the soft fruits) 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 entire surface is flat, and the bottom of the container 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 perpendicularly (90 degrees) to the container bottom 3; they may be inclined.

[0016] <Soft fruit> In this invention, a soft fruit refers to a fruit with a thin peel and soft flesh that is 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 the present invention is particularly effective for soft fruits that are small in size, 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 11 to 16 shows strawberries 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 (maximum / minimum) of the diameter of the largest soft fruit 6 to the diameter of the smallest soft fruit 6 is preferably 1.5 or less, more preferably 1.3 or less, and particularly preferably 1.1 or less.

[0018] <Conditions (single-row 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 packing 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, In such cases, the soft fruit 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 damage may occur to the surface of the soft fruit 6. Furthermore, it is preferable that multiple soft fruits 6 are in contact with at least two other soft fruits 6. Furthermore, it is preferable that the multiple soft fruits 6 are 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 make up the container 2. By having a 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 bump against 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 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 multiple soft fruits 6 are in contact with the heat-shrinkable film 7. By having 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, vibrations may cause the soft fruits 6 to repeatedly collide mainly with the bottom of the container 3 and other soft fruits 6, which may cause 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. This arrangement of soft fruits 6 allows the heat-shrinkable film 7 to more firmly secure the stored soft fruits 6 within 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 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 that form 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, being highly flexible, not only prevents damage to the surface of the soft fruit 6 from pressure and friction, but also provides the following effects to the soft fruit packaging 1. Specifically, 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 from the bottom of the container 3 than the virtual flat surface 9 by the thickness of the foamed synthetic resin sheet 8. Therefore, the heat-shrinkable film 7 can more firmly secure 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 also in contact with each of the four side walls 4 of the container, the foamed synthetic resin sheet 8 will fill the storage space 5 by its volume. This allows the interior to be filled, and the gaps between the soft fruits 6 can be made 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 better prevented.

[0025] For soft fruits in a soft fruit packaging, the electrical conductivity of the aqueous solution in which the soft fruits were immersed after a vibration test, measured by the evaluation method described below, is preferably reduced by 20% or more, using the electrical conductivity of a soft fruit packaging in which the soft fruit packaging (single-layer flat packing) 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. [Electrical conductivity of aqueous solution in which soft fruit was immersed after vibration testing] (1) Vibration test Using a vibration testing apparatus, a sinusoidal uniform sweep vibration test is performed for 30 minutes on a container containing one or more soft fruit packages under the following conditions. (Conditions for vibration testing) Lower frequency limit: 10Hz, Upper frequency limit: 40Hz, Sweep time: 10 minutes, Number of sweeps: 3, Vibration direction: Simultaneous movement of 3 axes: X-axis (horizontal), Y-axis (horizontal), Z-axis (vertical), Gravitational acceleration: 0G~3G (m / s²) 2 (Dependent on frequency). (2) Measurement of electrical conductivity After the vibration test, the soft fruits removed from the container were placed in a solution of pure water (electrical conductivity 1.0 μS / cm) six times the total weight of the soft fruits. The solution containing the soft fruits was stirred for 30 minutes, and the electrical conductivity of the solution measured using an electrical conductivity meter was defined as the electrical conductivity of the solution containing the soft fruits after the vibration test. The reduction rate of the electrical conductivity is calculated by the following formula. Electrical conductivity reduction rate = ((EC N -EC S ) / ECN ) × 100 EC N The 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 The electrical conductivity of the soft fruit packaging material of the present invention, measured by the above evaluation method. 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 more preferably 70% or more. As a non-heat-shrinkable film, a so-called overlay film conventionally known for use in fruit packaging is used. Examples of such overlay films include biaxially oriented polystyrene film and biaxially oriented polypropylene film.

[0026] [Soft fruit packaging (two layers packed, top and bottom)] The present invention relates to a 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 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): Multiple soft fruits are in contact with at least one other. Condition (2): At least one soft fruit is in contact with each of the four side walls forming the container. Condition (3'): Of the multiple 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 multiple soft fruits, the soft fruits stored in the lower section are in contact with the bottom of the container.

[0027] Figure 4 shows multiple soft fruits 6 satisfying conditions (1), (2), (3') and (4'). The soft fruit package 1 is shown, with multiple soft fruits 6 packed in two layers, one above the other, in the storage space 5 of the container 2, and wrapped in a heat-shrinkable film 7 that covers the entire perimeter of the container 2. Note that in Figures 4 and 5, the heat-shrinkable film 7 is shown in light gray.

[0028] Container 2 is as described above under <Container>. Regarding soft fruit 6, it is as described above under <Soft Fruit>.

[0029] <Conditions (stacked in two columns, top and bottom)> The soft fruit packaging body 1 (two-tiered, upper and lower) of the present invention is characterized in that a plurality of soft fruits 6 are stored in the storage space 5 of the container 2 in two layers, upper and lower, 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 fruit 6 may be damaged. Furthermore, it is preferable that multiple soft fruits 6 are in contact with at least two other soft fruits 6. Furthermore, condition (1) is more preferably condition (1') below. That is, the soft fruit 6 stored in the upper section is in contact with at least one of the soft fruit 6 stored in the upper section, and the soft fruit 6 stored in the lower section is in contact with at least one of the 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 be arranged in a staggered pattern.

[0031] As shown in Figure 6, condition (2) is that at least one soft fruit 6 is in contact with each of the four container side walls 4 that make up the container 2. By having soft fruits 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 fruits 6 are not in contact with the container side walls 4, vibrations may cause soft fruits 6 near the container side walls 4 to repeatedly bump against the container side walls 4, which may cause damage to the surface of the soft fruits 6. Furthermore, as shown in Figure 5(a), it is preferable that at least one soft fruit 6 is in contact with each of the four container side walls 4 forming the container 2, and that at least one other soft fruit 6 is in contact with two container side walls 4 simultaneously. It is even more preferable that at least one soft fruit 6 stored in the upper section is in contact with each of the four container side walls 4 forming the container 2, that at least one other soft fruit 6 stored in the upper section is in contact with two container side walls 4 simultaneously, and that at least one soft fruit 6 stored in the lower section is in contact with two container side walls 4 simultaneously.

[0032] As shown in Figure 6, condition (3') is that of the multiple soft fruits 6, the soft fruits 6 stored in the upper layer are in contact with the heat-shrinkable film 7, and the soft fruits 6 stored in the lower layer are in contact with the soft fruits 6 stored in the upper layer. When the multiple soft fruits 6 stored in the upper layer are 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 that it does not move. On the other hand, if the soft fruits 6 stored in the lower layer are not in contact with the soft fruits 6 stored in the upper layer, the soft fruits 6 stored in the upper layer may repeatedly collide with the bottom of the container 3 and other soft fruits 6 due to vibration, and therefore there is a risk that the surface of the soft fruits 6 may be damaged.

[0033] As shown in Figure 6, condition (4') is that among the multiple soft fruits, the soft fruits 6 stored in the lower section are in contact with the bottom of the container 3. There are soft fruits 6 that are not in contact with the bottom of the container 3. As a result, the soft fruit 6 may be violently struck against the bottom 3 of the container by the vibration, and therefore there is a risk that the surface of the soft fruit 6 may be damaged.

[0034] It is preferable that the soft fruits 6 stored in the upper layer are stored so that they 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 6. This arrangement of the soft fruits 6 in the upper layer allows the heat-shrinkable film 7 to more firmly secure the soft fruits 6 within the storage space 5. In a two-tiered arrangement, it is preferable that more than half of the soft fruits stored in the upper layer are stored in this manner, and it is particularly preferable that all of the soft fruits stored in the upper layer are stored in this manner.

[0035] As shown in Figure 8, in another embodiment, 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, at least one soft fruit 6 may be in contact with each of the four container side walls 4 that form the container 2 via a conventionally known elastic and flexible foamed synthetic resin sheet 8. Furthermore, as shown in Figure 8, by placing a foamed synthetic resin sheet 8 in contact with the bottom 3 of the container, the multiple soft fruits 6 stored in the upper section 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 3 of the container. Therefore, the heat-shrinkable film 7 can more firmly secure the soft fruits 6 in the storage space 5, and damage to the soft fruits 6 due to vibration can be more effectively prevented. Furthermore, when a foamed synthetic resin sheet 8 is laid 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 own volume, making the gaps between the soft fruits 6 smaller. Therefore, even if vibration is 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 vibration can be better 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. 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 more preferably 70% or more.

[0037] [Soft fruit packaging (with cushioning tray containing soft fruit)] The present invention relates to a soft fruit package 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 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-shrinkable 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): In the soft fruit storage section of the cushioning tray, the side opposite to the side in contact with multiple soft fruits is in contact with the bottom of the container. Condition (a): Multiple soft fruits are in contact with a heat-shrinkable film.

[0038] Figure 11 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 11), a buffer tray 10, and a container 2. Note that in Figures 11 and 12, the heat-shrinkable film Mu7 was shown in light ink.

[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, 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.

[0040] The bottom of the container 3 does not need to be flat. The bottom of the container 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 perpendicularly (90 degrees) to the container bottom 3; they may be inclined. Regarding soft fruit 6, it is as described above under <Soft Fruit>.

[0041] <Cushioning tray> The buffer 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. Specifically, by storing the soft fruits 6 in the soft fruit storage section 11, it prevents damage such as scratches caused by pressure and friction on the surfaces of the soft fruits 6. In addition, the cushioning tray 10 allows multiple soft fruits 6 to be stored so that they protrude more from the bottom 3 of the container than the virtual flat surface 9 shown in Figure 13. Therefore, the heat shrink film 7 can more firmly secure 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, by storing the soft fruit 6 in the soft fruit storage section 11, the movement of the soft fruit 6 is restricted even if vibration is applied to the cushioning tray 10, thereby further preventing damage to the soft fruit 6 due to vibration. Multiple soft fruits 6 stored in the buffer tray 10 may be in contact with other soft fruits 6.

[0042] <Conditions (with a cushioning tray that has a compartment for soft fruits)> The soft fruit packaging body 1 of the present invention (with a buffer tray having a 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 multiple soft fruits comes into contact with the bottom of the container 3. The back surface 11B is in contact with the bottom of the container 3, which prevents the cushioning tray 10 from forcefully hitting the bottom of the container 3 due to vibration, and therefore makes it less likely for damage to occur to the surface of the soft fruit 6 stored in the soft fruit storage section 11 of the cushioning tray 10.

[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] The multiple soft fruits 6 stored in the soft fruit storage section 11 are placed in a container as shown in Figure 13. It is preferable that the soft fruits 6 are stored so that they protrude at least 0.01 mm above the virtual plane portion 9 connecting the upper ends 4A of the side walls. Storing the soft fruits 6 in this manner allows the soft fruit storage section 11 to firmly secure the soft fruits 6 containing the heat-shrinkable film 7. 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 a vibration test measured by the above evaluation method is preferably 20% or more, based on the electrical conductivity of a soft fruit packaging in which the soft fruit packaging (with a cushioning 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, compared to the electrical conductivity of the soft fruit packaging (with a cushioning tray having a soft fruit storage section) 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 more preferably 70% or more.

[0047] [Soft fruit packaging (container with a soft fruit storage section at the bottom)] The present invention relates to a soft fruit package comprising a container having a substantially rectangular container bottom having a soft fruit storage section 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 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-shrinkable 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): Multiple soft fruits are in contact with a 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 roughly 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 extending upward from the entire periphery of the container bottom 23, forming 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 container bottom 23 has a soft fruit storage section 111 with multiple recesses 111A, which 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 such as scratches caused by pressure and friction on the surfaces of the soft fruits 6. 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, thereby further preventing damage to the soft fruits 6 due to vibration. Furthermore, a thermoplastic synthetic resin sheet may be placed or attached to the bottom 23 of the container, and soft fruits 6 may be stored on top of it. In this way, multiple soft fruits in the soft fruit storage section 111 The surface that contacts the fruit and the soft fruit 6 no longer come into direct contact, which further prevents damage to the soft fruit 6 due to vibration. Thermoplastic synthetic resin sheets are thin films 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 be in contact with other soft fruits 6. The four container side walls 24 do not need to extend upward perpendicularly (90 degrees) to the container bottom 23; they may be inclined. Regarding soft fruit 6, it is as described above under <Soft Fruit>.

[0051] <Condition (The container has a compartment at the bottom for storing soft fruits)> The soft fruit packaging body 1 of the present invention (having a soft fruit storage section at the bottom of the container) 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 manner 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, with the heat-shrinkable film 7 inside, to be more firmly secured in 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 a vibration test measured by the above evaluation method is preferably 20% or more, based on 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. 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 more preferably 70% or more.

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

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

[0057] Preferably, the heat-shrinkable film has a heat shrinkage force of 0.05 N / cm to 0.10 N / cm for the medium-density (MD) and a heat shrinkage force of 0.001 N / cm to 0.08 N / cm for the tangential (TD) at 80°C. Furthermore, it is preferable that the heat shrinkable film has a heat shrinkage force of 0.05 N / cm to 0.20 N / cm for the medium-density (MD) and a heat shrinkage force of 0.02 N / cm to 0.18 N / cm for the tangential (TD) at 100°C. Furthermore, it is preferable that the heat shrinkable film has a heat shrinkage force of 0.25 N / cm or less for the medium-density (MD) and 0.22 N / cm or less for the tangential (TD) at 120°C. Thermal shrinkage force is measured in accordance with ASTM-D2838.

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

[0059] The heat-shrinkable film is a laminated film having a layer made of a polyolefin resin. Here, the layer made of a polyolefin resin means a layer in which the resin component is only a polyolefin resin and optionally contains other additives or the like.

[0060] The polyolefin resin in the layer made of the polyolefin resin is preferably a polyethylene resin, a polypropylene resin, a polybutene resin, or a cyclic olefin copolymer, and more preferably a polyethylene resin. The polyolefin resin contained in the layer made of the polyolefin resin may be one type or a plurality of types.

[0061] Examples of the polyethylene resin include an ethylene homopolymer, an ethylene-α-olefin copolymer, an ethylene-vinyl acetate copolymer, and the like. Examples of the 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 the ultra-low-density polyethylene include linear ultra-low-density polyethylene (referred to as "LVLDPE" or "LULDPE").

[0062] Polyethylene resins are classified by density based on JIS K 6922. In this classification, polyethylene resins with a density of 0.942 g / cm 3 or higher are regarded as high-density polyethylene (HDPE), and polyethylene resins with a density of 0.930 g / cm 3 or higher and less than 0.942 g / cm 3 are regarded as medium-density polyethylene (MDPE), and polyethylene resins with a density of 0.910 g / cm 3 or higher and less than 0.930 g / cm3 Polyethylene resins with a density of less than 0.910 g / cm³ are called low-density polyethylene (LDPE), and their density is 0.910 g / cm³. 3 Polyethylene resins with a density of less than 100% are classified as ultra-low-density polyethylene. The density mentioned above refers to the value measured in accordance with JIS K 6922. Specifically, one method of measuring density is to measure it using a density gradient pipe, in accordance with 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. It can be used. As the ethylene-α-olefin copolymer mentioned above, copolymers of ethylene and at least one comonomer selected from propylene comonomer, butene comonomer, hexene comonomer, and octen comonomer are generally readily available and suitably used. Ethylene-α-olefin copolymers are sometimes referred to as polyethylene elastomers. The polymerization catalyst used in the production of 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 a 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, or thermal properties between plant-derived resins and petroleum-derived resins, the biomass degree defined in ISO 16620 or ASTM D6866 is generally used to distinguish between them. In the atmosphere, 10 12 Radioactive carbon at a rate of 1 per individual 14 Since carbon is present and this ratio does not change even with atmospheric carbon dioxide, this ratio remains unchanged even in plants that fix carbon dioxide through photosynthesis. For this reason, the carbon in plant-derived resins is radioactive carbon. 14 It contains C. 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 measured 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 include layers other than the layer made of polyolefin resin, but it is preferable that the laminated film consists only of the layer made of polyolefin resin. Each layer constituting the laminated film may have the same composition or different compositions. The layer structure of a laminated film may, for example, have a surface layer as the outermost layer and an intermediate layer in the interior. Examples include layered structures having a core layer, and more specifically, the following examples are given. With this layered structure, the effects of the present invention are even more pronounced. ·Surface layer / core layer / surface layer ·Surface layer / middle layer / core layer / middle 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 the conditions of 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 containing at least one resin component 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 the resin component, the MFR of the 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 components 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 components 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 components 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 components 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 long-chain branched low-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 long-chain branched low-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. In the case where the core layer contains linear low-density polyethylene and high-density polyethylene as resin components. In total, 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 component 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 component of the core layer.

[0076] (Middle class) The intermediate layer, which is the inner layer, is preferably a layer containing at least one resin component 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 the resin component, the MFR of 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 components of the intermediate 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 components of the intermediate layer.

[0078] When the intermediate 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. When the intermediate layer contains linear low-density polyethylene and long-chain branched low-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 intermediate layer, and the content of long-chain branched low-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 intermediate layer. When the intermediate 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 intermediate 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 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 for the surface layer may be used in the intermediate layer and / or core layer, the resin components listed for the intermediate layer may be used in the core layer and / or surface layer, and the resin components listed 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. Also, 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-hole is calculated by treating the small through-hole as a perfect circle based on its opening area.

[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 organosulfur, organonitrogen-sulfur, organohalogen, haloallylsulfone, 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, benzylbromoacetate, and inorganic salts, as well as other known compounds. Antifungal agents can be used individually or in combination of two or more types. The antifungal agent may be included in any of the layers, for example, when the heat-shrinkable film has a surface layer, an intermediate layer, and a core layer. The amount of the antifungal agent 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, and for example, 0.1% to 5.0% by mass, relative to the total mass of each layer (for example, each intermediate layer if there are two intermediate layers). The amounts of fungicide added to the surface layer, intermediate layer, and core layer may be the same or different.

[0085] Examples of anti-fogging 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. Anti-fogging agents can be used individually or in combination of two or more types. The amount of anti-fogging 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. As an antiblocking agent, any known particles can be used as long as they do 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 visible light. As an antiblocking agent, for example Examples 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, cross-linked polymethyl methacrylate particles, and cross-linked polystyrene particles, or mixtures thereof.

[0088] While antiblocking agents may be added to all layers, considering factors such as cost and reduced transparency, it is preferable to add them to the surface layer and intermediate layer, for example, if the heat-shrinkable film has a five-layer structure of surface layer / intermediate layer / core layer / intermediate layer / surface 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. Furthermore, the core layer may contain scrap resin generated during the manufacturing process of the heat-shrinkable film, as long as it does not hinder the effects of the present invention. Therefore, the core layer may contain additives (e.g., antiblocking agents) 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. [Examples]

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

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

[0092] Furthermore, the abbreviations represent the following meanings. LL1: Linear low-density polyethylene (single-site catalyst, density: 0.913 g / cm³) 3 MFR: 2.4g / 10min, Melting peak temperature: 102℃, α-olefin: 1-hexene) LL2: Linear low-density polyethylene (multi-site catalyst, density: 0.920 g / cm³) 3 MFR: 0.5g / 10min, Melting peak temperature: 122℃, α-olefin: 4-methyl-1-pentene) LL3: Linear low-density polyethylene (multi-site catalyst, density: 0.920 g / cm³) 3MFR: 2.1g / 10min, Melting peak temperature: 122℃, α-olefin: 1-butene) VL1: Ultra-low density polyethylene (density: 0.905 g / cm³) 3 MFR: 0.8g / 10min, Melting peak temperature: 96℃, α-olefin: 1-octene) HD1: High-density polyethylene (density 0.968 g / cm³) 3 (MFR: 5.2g / 10min, Melting peak temperature: 115℃) 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: Anti-fogging agent (glycerin fatty acid ester) AFA2: Anti-fogging 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, followed by granulation. MB2: A masterbatch pellet obtained by melt-kneading 90 parts by mass of linear low-density polyethylene and 10 parts by mass of ABA, followed by granulation.

[0093] (Manufacturing of polyethylene-based crosslinked heat shrink wrap film (film 1)) The resins shown in Table 1 were melt-kneaded using three extruders, and the molten resin, consisting of five layers—two surface layers, two intermediate layers, and one core layer—was extruded through an annular die into a tube shape. The tube was then rapidly cooled with water to obtain an unstretched film. At this time, the thickness ratio 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 260kV and an absorbed dose of 110kGy, and then similarly irradiated from the opposite side to perform crosslinking treatment. After that, the tubular unstretched film was guided to a tubular biaxial stretching apparatus. 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. The film was stretched in the MD (longitudinal direction) by the peripheral speed ratio of a low-speed nip roll and a high-speed nip roll, and stretched in the TD (width direction) with pressurized air. The film was folded while cooling by applying cold air to the bottom of the bubbles with an air ring, and a 4% relaxation heat treatment was performed on a heated roll at 85°C to obtain a polyethylene crosslinked heat shrink wrap film (hereinafter also referred to as film 1) with a thickness of 10.2 μm. The thermal shrinkage rate and thermal 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] [Table 1]

[0095] [Example 1] Strawberries (Amaou® Fukuoka S6, harvested in winter) were packed flat in a single layer in a polyethylene terephthalate container (approximately 30g / strawberry, 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 container, and then heat-treated 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 / strawberry, 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-treated 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] Except for placing a foamed polyurethane sheet for cushioning between the polyethylene terephthalate container and the strawberries, the same procedure as in producing the soft fruit packaging of Example 1 was followed to obtain the soft fruit packaging of Example 3 (a cross-sectional view of the soft fruit packaging of Example 3 is shown in Figure 7).

[0098] [Example 4] Except for covering the entire circumference of the strawberries and container with film 1 and heat-treating it, an OPP film was placed on top (covering the top of the container opening), and the same procedure as for producing the soft fruit packaging of Example 1 was followed to obtain the soft fruit packaging of Example 4.

[0099] [Example 5] Except for covering the entire perimeter of the strawberries and container with film 1 and then heat-treating it, an OPP film was added on top, and the same procedure as for producing the soft fruit packaging of Example 2 was followed to obtain the soft fruit packaging of Example 5.

[0100] [Example 6] Except for placing a buffer foamed polyurethane sheet between the polyethylene terephthalate container and the strawberries, the same procedure as for producing the soft fruit packaging in Example 4 was followed to obtain the soft fruit packaging in Example 6.

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

[0102] [Example 8] Except for using film 2 instead of film 1, the same procedure as in producing the soft fruit packaging of Example 1 was followed to obtain the soft fruit packaging of Example 8. Since several strawberries were crushed when film 2 was heat-shrinked, the vibration test described later was not performed.

[0103] [Example 9] A foamed polyethylene buffer tray (8-strawberry capacity) with a compartment for soft fruit was placed inside a polypropylene container. Strawberries (Koiminori variety, harvested in winter) were placed in the soft fruit compartment (approximately 25g / strawberry, 180g standard), and the container was wrapped in heat-shrinkable film. Film 1 was used for the wrapping. Film 1 covered the entire area around the strawberries and the container, and then heat-treated for 3 seconds in a shrink tunnel set to 137°C to heat-shrink Film 1, thereby obtaining the soft fruit packaging of Example 9.

[0104] [Example 10] Except for covering the entire perimeter of the strawberries and container with film 1 and then heat-treating it, an OPP film was added on top, and the same procedure as for producing the soft fruit packaging of Example 9 was followed to obtain the soft fruit packaging of Example 10.

[0105] [Example 11] Except for using strawberries (Koiminori, harvested in winter, weighing approximately 25g / piece) instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as the soft fruit, the same procedure as for producing the soft fruit package in Example 1 was followed to obtain the soft fruit package in Example 11.

[0106] [Example 12] Except for using strawberries (Koiminori, harvested in winter, weighing approximately 25g / piece) instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as the soft fruit, the same procedure as for producing the soft fruit package in Example 4 was followed to obtain the soft fruit package in Example 12.

[0107] [Example 13] As a soft fruit, instead of strawberries (Amaou (registered trademark) Fukuoka S6, harvested in winter) Using Chigo (Koiminori variety, harvested in winter, with strawberries weighing approximately 25g each), and using a suspended container designed for 15 strawberries, the same procedure as for manufacturing the soft fruit packaging of Example 7 was followed to obtain the soft fruit packaging of Example 13, except that 15 strawberries were packed into each container.

[0108] [Example 14] In a suspended container, 11 strawberries (Koiminori variety, harvested in winter, approximately 25g per strawberry) were packed into 220g-280g standard containers (11-berry capacity) 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-treated for 3 seconds in a shrink tunnel set to 137°C to heat-shrink Film 1, thereby obtaining the soft fruit packaging of Example 14.

[0109] [Example 15] Except for using strawberries (Koiminori, harvested in winter, weighing approximately 25g / piece) instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as the soft fruit, the same procedure as for producing the soft fruit package in Example 2 was followed to obtain the soft fruit package in Example 15.

[0110] [Example 16] Except for using strawberries (Koiminori, harvested in winter, weighing approximately 25g / piece) instead of strawberries (Amaou® Fukuoka S6, harvested in winter) as the soft fruit, the same procedure as for producing the soft fruit package in Example 5 was followed to obtain the soft fruit package in Example 16.

[0111] <Vibration test for measuring electrical conductivity> For the soft fruit packaging examples 1, 2, 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, and 16, which were 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 its manufacture until the day of the vibration test. The vibration test was conducted in accordance with 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. Two packs of soft fruit packaging for Examples 1, 3, 6, 9, and 10 were packed per cardboard box. Four packs of soft fruit packaging for Examples 2 and 5 were packed per cardboard box. One pack of soft fruit packaging for Examples 7, 13, and 14 was packed per cardboard box. In addition, two packs each of Examples 11 and 15 were packed per cardboard box, for a total of four packs. In addition, two packs each of Examples 12 and 16 were packed per cardboard box, for a total of four packs. Assuming resonance, a sinusoidal uniform sweep vibration test was performed for 30 minutes on each 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 apparatus. The conditions for the vibration test are shown below. (Conditions for vibration testing) Lower frequency limit: 10Hz, Upper frequency limit: 40Hz, Sweep time: 10 minutes, Number of sweeps: 3, Vibration direction: Simultaneous movement of 3 axes: X-axis (horizontal), Y-axis (horizontal), Z-axis (vertical), Gravitational acceleration: 0G~3G (m / s²) 2 (Dependent on frequency).

[0112] <Evaluation of the degree of damage to soft fruits due to vibration (measurement of electrical conductivity)> To evaluate the degree of damage to the strawberries caused by vibration, we used the electrical conductivity of the strawberry immersion solution as a measure of the 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, p1392-1395. Electrical conductivity was measured on the same day that the vibration test described above was performed. Examples 1, 2, 3, 5, 6, 7, 9, 10, 13 and 14, as well as Examples 11 and 15, after the vibration test described above, and For the soft fruit packaging in Examples 12 and 16, 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 testing for sensory evaluation> For the soft fruit packaging examples 1, 2, 3, 5, 6, and 7, which will be subject to sensory evaluation later, vibration tests were conducted immediately after their manufacture. The method and conditions for the vibration test are as described above in <Vibration Test for Electrical Conductivity Measurement>. These soft fruit packages used for sensory evaluation were stored in a refrigerator at 12°C for two days after the vibration test.

[0114] <Evaluation of the degree of damage to soft fruit due to vibration (sensory evaluation)> Strawberries were removed from the soft fruit packaging 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 examined visually. Based on Reference 1, the degree of damage was determined by visually counting the number of achenes including the damaged area for each strawberry and dividing by the total number of achenes to calculate the percentage of damaged area for each pack. Regarding the total number of achenes, analysis of 25 packs revealed that the average total number of achenes (AN) and the average weight (FW(g)) per fruit per pack were investigated, and AN = 43.415 × FW 0.6089 (R 2 Since 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, occé (damage involving deformation of strawberries due to collisions between strawberries or between strawberries and containers), and abrasion (damage caused by friction between strawberries or containers). 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 freight transport" (2017), Horticultural Science Research, Vol. 16, pp. 95-104.

[0115] As shown in Figure 9, the soft fruit packaging in Example 1, which was wrapped in heat-shrinkable film, had an electrical conductivity of approximately 20.2 μS / cm for the strawberry immersion solution. Furthermore, in Example 6, the soft fruit packaging, in which the top of the container opening was covered with OPP film (conventional overlay film (non-heat-shrinkable film)) and a foamed polyurethane sheet for cushioning was laid down, had an electrical conductivity of approximately 15.7 μS / cm for the strawberry immersion solution. Compared to Example 1, the electrical conductivity results for the soft fruit packaging in Example 6 did not show a statistically significant difference at the 5% level using the Mann-Whitney U test. Therefore, the degree of damage to strawberries in soft fruit packages wrapped in heat-shrinkable film without a buffer foam polyurethane sheet was the same as the degree of damage to strawberries in soft fruit packages wrapped with OPP film covering the top of the container opening and with a buffer foam polyurethane sheet. 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. Furthermore, the reduction rate of the electrical conductivity in Example 3, using the electrical conductivity of Example 6 as a baseline, was approximately 59%. Therefore, wrapping the strawberries in heat-shrinkable film reduced the degree of damage. Furthermore, as shown in Figure 9, the soft fruit packaging in Example 5, which was packaged 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. Ta. 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. Furthermore, using the electrical conductivity of Example 5 as a baseline, the reduction rate of the electrical conductivity in Example 2 was approximately 71%. The results for the electrical conductivity of soft fruit packaging materials between Example 3 and Example 6, and between Example 2 and Example 5, showed statistically significant differences at the 1% and 5% levels, respectively, using the Mann-Whitney U test. Therefore, the degree of damage to the strawberries was reduced in both single-layer and double-layer (top and bottom) packing. On the other hand, in Example 7, a soft fruit packaging in which strawberries were packed in a suspended container, the electrical conductivity of the strawberry immersion solution 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 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, as shown in Figure 17, the soft fruit packaging in Example 9, which was wrapped in 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, in which the upper opening of the container was covered with OPP film and a buffer tray was placed, had an electrical conductivity of approximately 10.9 μS / cm for the strawberry immersion solution. Using the electrical conductivity of Example 10 as a baseline, the reduction rate of the electrical conductivity in Example 9 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. Furthermore, 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 was 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 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 in which a buffer tray with a soft fruit storage section is placed within the storage space, and which is wrapped with heat-shrinkable film covering the entire perimeter of the container, and which meets certain 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 opening of the container instead of heat-shrinkable film. Furthermore, the soft fruit packaging in Example 9 showed a greater reduction in the degree of damage to strawberries compared to the soft fruit packaging in Example 13, which used a suspended container. Furthermore, after placing the soft fruit packaging materials of Examples 11 and 15, which were obtained by changing the type of strawberry from the soft fruit packaging materials of Examples 1 and 2, into a container (cardboard box) and conducting a vibration test, the electrical conductivity of the strawberry immersion solution 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. Furthermore, the results for the electrical conductivity of soft fruit packaging materials between Examples 11 and 15 and Examples 12 and 16 showed statistically significant differences 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. Furthermore, in Example 6, a soft fruit package in which the opening of the container was covered with OPP film and a foamed polyurethane sheet was laid down as a buffer, damage was observed on approximately 24.4% of the surface area of ​​the strawberries. Compared to Example 1, the sensory evaluation of the percentage of damaged strawberry area in Example 6's soft fruit packaging did not show a statistically significant difference at the 5% level using the Mann-Whitney U test. Therefore, the degree of damage to strawberries in soft fruit packages wrapped in heat-shrinkable film without a buffer foam polyurethane sheet was the same as the degree of damage to strawberries in soft fruit packages wrapped with OPP film covering the top of the container opening and with a buffer foam polyurethane sheet. Furthermore, in Example 3, the soft fruit packaging, which was wrapped in heat-shrinkable film and lined with a cushioning foamed polyurethane sheet, showed damage to approximately 12.7% of the strawberry surface area. Therefore, wrapping the strawberries in heat-shrinkable film reduced the degree of damage. Furthermore, as shown in Figure 10, the soft fruit packaging in Example 5, which was wrapped with OPP film covering the top of the container opening, showed damage to approximately 46.6% of the strawberry surface area. On the other hand, in Example 2, the soft fruit packaging, which was wrapped in heat-shrinkable film, showed damage to approximately 15.4% of the strawberry surface area. The percentage of damaged strawberry area, as determined by sensory evaluation of soft fruit packaging, showed statistically significant differences at the 5% level using the Mann-Whitney U test between Example 3 and Example 6, and between Example 2 and Example 5. Therefore, the degree of damage to the strawberries was reduced in both single-layer and double-layer (top and bottom) packing. On the other hand, in Example 7, where strawberries were packed in a suspended container, the percentage of damaged area 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. [Industrial applicability]

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

[0118] 1. Soft fruit packaging 2 containers 3 Bottom of container 4. Container side wall 4A Upper end of the side wall of the container 5 Storage space 6. Soft fruit 7 Heat shrink film 8. Foamed synthetic resin sheet 9. Virtual Planar Section 10 cushioning trays 11 Soft fruit storage section 11A recess 11B The surface opposite to the surface in contact with multiple soft fruits in the soft fruit storage section. 22 Container 23 Bottom of container 24 Container side wall 24A Upper end of the side wall of the container 111 Soft fruit storage section 111A Recess 111B The surface opposite to the surface in contact with multiple soft fruits in the soft fruit storage section.

Claims

1. 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 shrinkable 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): Multiple soft fruits are in contact with a heat-shrinkable film.

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

3. The soft fruit packaging according to claim 1, 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.

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

5. The aforementioned heat-shrinkable film is At 120°C, the thermal shrinkage rates in the MD (longitudinal direction) and TD (width direction) are both 58% to 67%, the thermal shrinkage force in the MD at 120°C is 0.25 N / cm or less, and the thermal shrinkage force in the TD at 120°C is 0.22 N / cm or less. The soft fruit packaging according to claim 1, wherein the tensile modulus of MD is 0.25 GPa to 0.29 GPa, and the tensile modulus of TD is 0.25 GPa to 0.27 GPa.

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

7. The soft fruit packaging according to claim 1, 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, 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 opening of the container. [Electrical conductivity of aqueous solution in which soft fruits were immersed after vibration testing] (1) Vibration test Using a vibration testing apparatus, a sinusoidal uniform sweep vibration test is performed for 30 minutes on a container containing one or more soft fruit packages under the following conditions. (Conditions for vibration testing) Lower frequency limit: 10 Hz, Upper frequency limit: 40 Hz, Sweep time: 10 minutes, Number of sweeps: 3, Vibration direction: Simultaneous movement of three axes: X-axis (horizontal), Y-axis (horizontal), Z-axis (vertical), Gravitational acceleration: 0G to 3G (m / s²) ２ (Dependent on frequency). (2) Measurement of electrical conductivity After the vibration test, the soft fruits removed from the container were placed in a solution of pure water (electrical conductivity 1.0 μS / cm) six times the total weight of the soft fruits. The solution containing the immersed soft fruits was stirred for 30 minutes, and the electrical conductivity of the solution measured using an electrical conductivity meter was defined as the electrical conductivity of the solution containing the soft fruits after the vibration test.

Images