Film, packaging container, and packaging container with content

Abstract

To provide a film that can stably discharge vapor, a packaging container, and a packaging container with contents.SOLUTION: A film 3, which is used in a packaging container 2 and 2A, comprises a seal part 12c that is sealed on a flange 23 provided on an opening end of a container main body 11 with a bottom formed in a rectangular shape which is long in one direction or sealed overlapping thereon in the rectangular frame shape that is long in one direction, and a linear processing part 12a that forms a fractured part 12b that is fractured by an increase in inner pressure thereof. The processing part 12a inclines along a reference line C along a short side of an inner peripheral edge of the seal part 12c or at an angle between the reference line C and a diagonal line of the seal part 12c.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film, a packaging container, and a packaging container containing contents, which discharge steam generated when the packaged contents are heated in a microwave oven to the outside.

Background Art

[0002] Conventionally, a container that houses contents and heats the contents in a microwave oven in a sealed state has been known. When such a container heats the contents by a microwave oven, the internal pressure increases. For this reason, a container having means for automatically discharging steam and reducing the internal pressure during microwave heating is also known.

[0003] For example, Patent Document 1 discloses a cup container and a film capable of discharging steam during microwave heating by providing a breaking portion having an unoriented portion disposed opposite to each other across an oriented portion of a crystalline stretched and oriented film.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above-described container that automatically discharges steam and reduces the internal pressure during microwave heating, the breaking portion may not break at a desired internal pressure. For this reason, due to the internal pressure of the container rising too much, bag breakage may occur.

[0006] Therefore, an object of the present invention is to provide a film, a packaging container, and a packaging container containing contents that can stably discharge steam.

Means for Solving the Problems

[0007] According to one aspect of the present invention, the film is sealed to a flange provided at an open end of a bottomed container body formed in a rectangular shape long in one direction, or is overlapped and sealed in a rectangular frame shape long in one direction, and includes a sealing portion, and a linear processed portion that forms a breaking portion that breaks due to an increase in internal pressure. The processed portion is along a reference line along the short side of the inner peripheral edge of the sealing portion, or is inclined at an angle between the reference line and the diagonal line of the sealing portion.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a film, a packaging container, and a packaging container containing contents that can stably discharge steam.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the configuration of the packaging container 1 with contents according to the embodiment of the present invention will be described with reference to FIGS. 1 to 12. FIG. 1 is a perspective view showing the configuration of the packaging container 1 with contents according to the embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of the container body 11 used for the packaging container 1 with contents. FIG. 3 is a plan view showing the configuration of the processed portion 12a of the lid 12 (film 3) used for the packaging container 1 with contents. FIG. 4 is an explanatory view schematically showing a plurality of examples and comparative examples of the packaging container 2 used in Evaluation Test 1. FIG. 5 is an explanatory view showing an example of the result of Evaluation Test 2, and FIGS. 6 to 11 are explanatory views showing an example of the analysis result of Evaluation Test 2.

[0011] As shown in FIG. 1, the packaging container 1 with contents includes a packaging container 2 and contents 100 accommodated in the packaging container 2. The packaging container 1 with contents is a packaging container for heating the contents 100 accommodated in the packaging container 2 by a microwave oven in a state where the packaging container 2 is sealed. Here, the contents 100 contain moisture that is heated by a microwave oven, and include, for example, foods cooked by heating with a microwave oven and articles such as wet wipes heated by a microwave oven.

[0012] The packaging container 2 is formed, for example, by using a film 3 having a processed portion 12a that breaks due to an increase in internal pressure as the lid 12, or by forming the film 3 into a bag shape. In the example of the present embodiment, the packaging container 2 includes a container body 11 and a lid 12 that seals the container body 11.

[0013] As shown in FIGS. 1 and 2, the container body 11 is a bottomed container capable of accommodating the content 100. The container body 11 is a container such as a cup shape, a dish shape, or a tray shape formed in a rectangular shape that is long on one side. That is, the container body 11 extends in a direction in which a pair of long sides and a pair of short sides are orthogonal. Note that the corners continuous with the long sides and the short sides of the container body 11 may be inclined with respect to the long sides and the short sides, or may be formed in a curved surface shape. In the present embodiment, an example in which the corners of the long sides and the short sides of the container body 11 are formed in a curved surface shape will be described. The container body 11 includes a body portion 21, a bottom portion 22, and a flange 23. The container body 11 is formed of, for example, a resin material, and as a specific example, polypropylene (PP) or polystyrene (PS). The container body 11 is formed by vacuum forming or pressure air forming. The container body 11 is set to have a size such that the area of the region defined by the outer peripheral edge of the flange portion 23a is 50 cm2 or more and 900 cm2 or less.

[0014] The lower end of the body portion 21 is closed by the bottom portion 22, and the upper end where the flange 23 is integrally formed is open. The body portion 21 is, for example, a rectangular shape that is long in one direction, and extends in a direction in which a pair of long sides and a pair of short sides are orthogonal. Further, for example, the corners continuous with the long sides and the short sides of the body portion 21 may be inclined with respect to the long sides and the short sides, or may be formed in a curved surface shape. In the present embodiment, the body portion 21 is formed in a curved surface shape in which the corners are curved with a predetermined radius of curvature. The body portion 21 includes, for example, a first side portion 21a that is integrally continuous with the bottom portion 22 and whose width gradually decreases from the flange 23 side toward the bottom portion 22, and a second side portion 21b that connects the upper end of the first side portion 21a and the flange 23.

[0015] The first side portion 21a is formed in a tapered shape that is inclined with respect to the axial direction of the body portion 21 such that the width gradually decreases from the flange 23 side toward the bottom portion 22 side. The second side portion 21b is set to have a width larger than the width of the upper end of the first side portion 21a.

[0016] The bottom portion 22 is integrally formed at the lower end of the body portion 21. The bottom portion 22 is formed in a flat plate shape. For example, the central side of the bottom portion 22 may protrude toward the flange 23 side more than the outer edge side.

[0017] The flange 23 is integrally formed, for example, at the upper end (open end) of the body portion 21. The flange 23 is formed in an annular shape extending in a direction orthogonal or intersecting with the axial direction of the body portion 21 along the outer peripheral shape of the body portion 21 from the upper end edge of the body portion 21. For example, the flange 23 has a rectangular shape that is long in one direction, and a pair of long sides and a pair of short sides extend in a direction orthogonal to each other. Further, for example, in the flange 23, the corners continuous with the long sides and the short sides are inclined with respect to the long sides and the short sides. The flange 23 includes, for example, a flat flange portion 23a, a skirt portion 23b extending downward from the outer edge of the flange portion 23a, and a hem portion 23c extending outward from the lower end of the skirt portion 23b.

[0018] The flange portion 23a is formed in an annular flat plate shape extending along the outer peripheral shape of the body portion 21. For example, the flange portion 23a is formed such that the width in a direction orthogonal to the extending direction is substantially constant, and has a rectangular shape that is long in one direction. For example, the corners continuous with the long sides and the short sides are inclined with respect to the long sides and the short sides. The lid 12 is heat-sealed to the upper surface of the flange portion 23a. As a specific example, a jig for heat-sealing is disposed on the lower surface of the flange portion 23a, and the lid 12 is heated while being pressed against the upper surface of the flange portion 23a, so that the lid 12 is heat-sealed to the flange portion 23a. The flange portion 23a is formed to be slightly inclined such that the outer edge side is downward with respect to, for example, being orthogonal to the vertical direction or with respect to a direction orthogonal to the vertical direction. The flange portion 23a is formed in an annular flat plate shape.

[0019] The skirt portion 23b is formed in a ring shape and extends downward from the outer edge of the flange portion 23a. The length of the skirt portion 23b is preferably 3 mm or more and 15 mm or less. More preferably, the length of the skirt portion 23b is 4 mm or more and 9 mm or less. Here, the length of the skirt portion 23b is the length along the outer surface extending downward of the skirt portion 23b from the ridge portion between the flange portion 23a and the skirt portion 23b to the ridge portion between the skirt portion 23b and the hem portion 23c. Also, the length of the skirt portion 23b may be different, for example, on the long side and the short side. In this case, for example, the length of the skirt portion 23b on the long side is longer than the length of the skirt portion 23b on the short side.

[0020] The hem portion 23c is formed in a ring shape and extends outward from the lower end of the skirt portion 23b. For example, the hem portion 23c extends outward along a direction orthogonal to the axial direction of the container body 11 from the lower end of the skirt portion 23b. The length of the hem portion 23c is preferably 1.5 mm or more and 10 mm or less. More preferably, the length of the hem portion 23c is 2.0 mm or more and 5.0 mm or less. Here, the length of the hem portion 23c is the length along the upper surface in the extending direction of the hem portion 23c from the ridge portion between the skirt portion 23b and the hem portion 23c to the end of the hem portion 23c. For example, the hem portion 23c is formed when the container body 11 is trimmed from a sheet material of a resin material, which is a molding material, during the molding of the container body 11.

[0021] Also, for example, the angle between the flange portion 23a and the skirt portion 23b is set to be 90 degrees or more and 120 degrees or less. Here, the angle between the flange portion 23a and the skirt portion 23b is the angle between the lower surface of the flange portion 23a and the inner surface of the skirt portion 23b. Also, for example, the angle between the skirt portion 23b and the hem portion 23c is set to be 60 degrees or more and 120 degrees or less. Here, the angle between the skirt portion 23b and the hem portion 23c is the angle between the outer surface of the skirt portion 23b and the upper surface of the hem portion 23c.

[0022] The container body 11 configured as described above can be formed in a stackable manner because the width of the body portion 21 decreases downward. For example, when the container bodies 11 are stacked, a predetermined interval, for example, an interval of 3 mm or more, is created in the axial direction between the lower end of the skirt portion 23b of the upper container body 11 and the upper surface of the flange portion 23a of the lower container body 11. Also, the plurality of container bodies 11 may have a plurality of ribs for stacking and reinforcement in order to provide a predetermined interval between adjacent container bodies 11 during stacking.

[0023] The lid 12 is formed of, for example, a film 3 having a resin layer capable of heat-sealing to the flange portion 23a. The lid 12 has a processing portion 12a that forms a breaking portion 12b which breaks when the internal pressure of the heat-sealed container body 11 rises and reaches a predetermined internal pressure or more. The processing portion 12a is formed in a part of the lid 12, and by breaking due to the increase in internal pressure, the breaking portion 12b is formed, and a steam vent through which steam escapes is formed by this breaking portion 12b. Various techniques can be applied to the processing portion 12a. That is, the processing portion 12a formed in the lid 12 may have, for example, a plurality of portions 12a1 with relaxed orientation, and a breaking portion may be formed between these portions 12a1 with relaxed orientation, as long as it can break due to the increase in internal pressure and form the breaking portion 12b serving as a steam vent. Also, the processing portion 12a may be formed by reducing the strength of a part of the lid 12, so that when the internal pressure rises, it breaks earlier than other parts of the lid 12 and a breaking portion 12b is formed in a part of the processing portion 12a.

[0024] Also, the lid 12 (film 3) is formed of a multilayer film having a seal layer on one main surface, for example, the main surface on the container body 11 side. The lid 12 is welded to the flange portion 23a of the container body 11 by heat-sealing or the like, thereby forming a seal portion 12c. Since the seal portion 12c is the region welded to the flange portion 23a, in the present embodiment, it is formed in an annular rectangular frame shape having the same shape as the flange portion 23a, for example, having a pair of long sides and a pair of short sides and being long in one direction.

[0025] The processing part 12a is formed in a long straight shape in one direction. Also, the processing part 12a may be configured to be formed in a single long straight shape in one direction, or may be configured to have a plurality of portions 12a1 formed in a long straight shape in one direction and arranged side by side in that one direction.

[0026] In the present embodiment, as shown in FIG. 3, the processing part 12a is formed by arranging a plurality of, for example, four portions 12a1 formed in a long straight shape in one direction side by side, and a break part 12b is formed between adjacent portions 12a1. As an example, the portion 12a1 is formed, for example, by heating the film 3 (lid 12) linearly with a laser beam or the like to cause non-crystallization and relieve or lose the orientation. In other words, the processing part 12a is formed in a long shape in one direction and by providing three partially unprocessed sites in the middle part in the longitudinal direction.

[0027] Such a processing part 12a that is long in one direction has its longitudinal direction arranged along the short side of the seal part 12c of the lid 12 or inclined at a predetermined angle, for example, an angle up to the diagonal line of the seal part 12c. The processing part 12a is preferably arranged with its longitudinal direction along the short side of the seal part 12c of the lid 12 or inclined within a range of ±30° as a predetermined angle with respect to the short side of the seal part 12c. In other words, with respect to the reference line C parallel to the short side of the inner peripheral edge of the seal part 12c, the longitudinal direction of the processing part 12a is set within a range of -30° to 30° (0° ± 30°). More preferably, with respect to the reference line C parallel to the short side of the inner peripheral edge of the seal part 12c, the longitudinal direction of the processing part 12a is set within a range of -10° to 10° (0° ± 10°).

[0028] Further, the processed portion 12a is provided in a region inside the inner peripheral edge of the seal portion 12c of the lid 12 (film 3) in the longitudinal direction of the lid 12 (seal portion 12c), and in a direction along the long side of the inner peripheral edge of the seal portion 12c, within a range of a distance up to 60% of the length from the center of the long side (longitudinal direction) of the inner peripheral edge of the seal portion 12c to the short side of the inner peripheral edge of the seal portion 12c. That is, the processed portion 12a is at least partially disposed inside the inner peripheral edge of the seal portion 12c and in the central 60% region in the direction along the long side of the inner peripheral edge of the seal portion 12c.

[0029] That is, as shown in each of the embodiments of FIGS. 1 and 4, in the region inside the inner peripheral edge of the seal portion 12c, when it is assumed that there is a reference line C along the short side at the center in the direction along the long side, the processed portion 12a is in a posture within an angular range from the posture along the reference line C to the posture along the diagonal line of the seal portion 12c, and is disposed within 60% of the range from the reference line C to the short side of the inner peripheral edge of the seal portion 12c.

[0030] The packaging container 1 containing the contents configured in this way has, in the region inside the inner peripheral edge of the seal portion 12c of the lid 12 (film 3), the longitudinal direction of the processed portion 12a along the reference line C along the short side of the inner peripheral edge of the seal portion 12c, or within an angular range from the reference line C to the diagonal line of the inner peripheral edge of the seal portion 12c, and is provided within a 60% range from the center in the longitudinal direction of the inner peripheral edge of the seal portion 12c. That is, the processed portion 12a is set within an angular range of 0° to θA, where θA is the angle of the diagonal line with respect to the reference line C with respect to the reference line C being 0°. With such a configuration, when the contents 100 in the packaging container 1 containing the contents are heated by a microwave oven, steam is generated from the moisture contained in the contents 100, the internal pressure rises, and the lid 12 (film 3) expands. When the lid 12 (film 3) expands, the linear processed portion 12a expands in a direction orthogonal to the longitudinal direction of the processed portion 12a, breaks at the breaking portion 12b, and the steam in the packaging container 2 escapes to the outside to perform steam venting.

[0031] When the lid 12 (film 3) extends evenly, the processing part 12a is formed parallel (0°) to the reference line C parallel to the short side of the inner peripheral edge of the seal part 12c, or is formed inclined with respect to the reference line C so as to be parallel to the diagonal line of the seal part 12c. As a result, the length by which the processing part 12a extends in the short side direction of the processing part 12a becomes longer, and the breaking part 12b becomes easier to break. In this way, by providing the lid 12 (film 3) so that the longitudinal direction of the processing part 12a is along the reference line C or within an angular range from the reference line C to the diagonal line of the inner peripheral edge of the seal part 12c, the breaking part 12b can be surely broken, and the packaging container 1 containing the contents can stably discharge steam.

[0032] Also, when the internal pressure of the packaging container 2 rises, deformation is likely to occur on the long side of the packaging container 2. That is, since the strength of the long side of the packaging container 2 is lower than that of the short side, when the lid 12 deforms into a dome shape due to the increase in internal pressure, the long side may deform. And when the processing part 12a is formed parallel to the long side of the inner peripheral edge of the seal part 12c in the packaging container 2, when deformation occurs on the long side of the packaging container 2, the force that causes the lid 12 (film 3) to extend in a direction perpendicular to the processing part 12a is suppressed, and the breaking part 12b becomes difficult to break. For this reason, the lid 12 (film 3) of the packaging container 2 of the embodiment is formed by making the linear processing part 12a parallel or inclined within a predetermined range with respect to the reference line C parallel to the short side of the inner peripheral edge of the seal part 12c, so that the breaking part 12b becomes easier to break.

[0033] Also, when the lid 12 deforms into a dome shape, by arranging it within a range of 60% from the center in the direction along the long side of the inner peripheral edge of the seal part 12c, since the processing part 12a is likely to extend in the short side direction, the breaking part 12b becomes easier to break. Therefore, the packaging container 2 can stably discharge steam.

[0034] Further, in the packaging container 1 containing the contents, the lid 12 deforms into a dome shape as the internal pressure rises. Generally, however, the long side of the flange portion 23a may deform more than the short side. However, by providing the skirt portion 23b on the flange 23 of the packaging container 2, the strength of the flange 23 can be improved. For this reason, when the contents 100 are heated in a microwave oven and the lid 12 expands into a dome shape, it is possible to suppress the deformation of the flange 23 due to the stress generated by the deformation of the lid 12, and the breaking portion 12b can be stably broken. Further, since the strength of the skirt portion 23b can be improved by providing the hem portion 23c extending outward from the lower end of the skirt portion 23b on the flange 23, the strength of the flange 23 can be further improved, and the deformation of the flange 23 can be further suppressed.

[0035] Next, as an example of the evaluation test of the container body 11 configured as described above, Evaluation Test 1 and Evaluation Test 2 will be described with reference to FIGS. 4 to 8. The evaluation test is for clarifying the characteristics of the container body 11 of the present embodiment, and the scope of the present invention is not limited to the following examples.

[0036] [Evaluation Test 1] As Evaluation Test 1, the packaging containers 2 of Examples 1 to 6 and the containers of Comparative Example 1 and Comparative Example 7 were produced, and samples in which the container bodies 11 of Examples 1 to 6 and the container bodies 11 of Comparative Example 1 and Comparative Example 7 were heat-sealed with the lid 12 in an empty state were produced. Further, the longitudinal length W1 of the flange 23 and the lid 12 of the container body 11 of the packaging container 2 was set to 153 mm, the lateral length W2 of the flange 23 and the lid 12 was set to 117 mm, the longitudinal length W3 at the inner peripheral edge of the seal portion 12c of the lid 12 was set to 134 mm, and the lateral length W4 at the inner peripheral edge of the seal portion 12c was set to 98 mm.

[0037] The lid 12 used a PET(16) / easy peel(30) film. In the processed part 12a formed on the lid 12, four parts 12a1 were formed so that three breaking parts 12b were formed, and the length of the processed part 12a in the longitudinal direction, that is, the distance between the end parts located outside the outermost part 12a1 in the arrangement direction was set to 46 mm. Also, a reference line C was set along the short side direction of the inner peripheral edge of the seal part 12c and at the center in the longitudinal direction of the inner peripheral edge of the seal part 12c.

[0038] In addition, as shown in FIG. 4, the packaging containers 2 of Examples 1 to 6 and the containers of Comparative Example 1 and Comparative Example 7 had different angles and positions of the processed part 12a that was long in one direction. Hereinafter, each processed part 12a of the packaging containers 2 of Examples 1 to 6 and the containers of Comparative Example 1 and Comparative Example 7 will be described.

[0039] For the packaging container 2 of Example 1, a processed part 12a along the reference line C was formed within the inner peripheral edge of the seal part 12c and on the reference line C. Also, for the packaging container 2 of Example 1, the center in the longitudinal direction of the processed part 12a was set as the center in the short side direction of the inner peripheral edge of the seal part 12c.

[0040] For the packaging container 2 of Example 2, a processed part 12a along the reference line C was formed within the inner peripheral edge of the seal part 12c and on the reference line C. Also, for the packaging container 2 of Example 2, the center in the longitudinal direction of the processed part 12a was set as the position shifted 20 mm from the center in the short side direction of the inner peripheral edge of the seal part 12c to one long side.

[0041] For the packaging container 2 of Example 3, a processed part 12a along the reference line C was formed at a position shifted 20 mm from the reference line C to one short side of the inner peripheral edge of the seal part 12c within the inner peripheral edge of the seal part 12c. Also, for the packaging container 2 of Example 3, the center in the longitudinal direction of the processed part 12a was set as the center in the short side direction of the inner peripheral edge of the seal part 12c.

[0042] The packaging container 2 of Example 4 has a processed portion 12a along the reference line C formed at a position within the inner peripheral edge of the seal portion 12c and shifted 40 mm from the reference line C to one short side of the inner peripheral edge of the seal portion 12c. That is, the packaging container 2 of Example 4 is provided in a range of a distance up to 60% of the length from the center in the longitudinal direction of the inner peripheral edge of the seal portion 12c to the short side of the inner peripheral edge of the seal portion 12c in the direction along the longitudinal direction of the inner peripheral edge of the seal portion 12c. Further, for the packaging container 2 of Example 4, the center in the longitudinal direction of the processed portion 12a is the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0043] The packaging container 2 of Example 5 has a processed portion 12a formed within the inner peripheral edge of the seal portion 12c and on the reference line C, and the processed portion 12a is inclined at 30° with respect to the reference line C. Further, for the packaging container 2 of Example 5, the center in the longitudinal direction of the processed portion 12a is the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0044] The packaging container 2 of Example 6 has a processed portion 12a formed within the inner peripheral edge of the seal portion 12c and on the reference line C, and the processed portion 12a is inclined at 45° with respect to the reference line C. Further, for the packaging container 2 of Example 6, the center in the longitudinal direction of the processed portion 12a is the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0045] As described above, for the packaging containers 2 of Example 1 to Example 6, the processed portion 12a is inclined in an angular range from an angle where the longitudinal direction of the processed portion 12a is along the short side (short-side direction) of the inner peripheral edge of the seal portion 12c to an angle along the diagonal line of the seal portion 12c with respect to the short-side direction, and at least a part of the processed portion 12a is arranged in a range of 60% from the center of the long side (longitudinal direction) of the inner peripheral edge of the seal portion 12c to the short side.

[0046] The packaging container 2 of Comparative Example 1 has a processed portion 12a along the reference line C formed at a position within the inner peripheral edge of the seal portion 12c and shifted 55 mm from the reference line C to one short side of the inner peripheral edge of the seal portion 12c. Further, for the packaging container 2 of Comparative Example 1, the center in the longitudinal direction of the processed portion 12a is the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0047] The packaging container 2 of Comparative Example 2 formed a processed portion 12a within the inner peripheral edge of the seal portion 12c and inclined 60° with respect to the reference line C. Further, for the packaging container 2 of Comparative Example 2, the center in the longitudinal direction of the processed portion 12a was set as the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0048] The packaging container 2 of Comparative Example 3 formed a processed portion 12a within the inner peripheral edge of the seal portion 12c and on the reference line C, inclined 90° with respect to the reference line C. Further, for the packaging container 2 of Comparative Example 3, the center in the longitudinal direction of the processed portion 12a was set as the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0049] The packaging container 2 of Comparative Example 4 formed a processed portion 12a within the inner peripheral edge of the seal portion 12c and at a position shifted 35 mm from the reference line C to one short-side of the inner peripheral edge of the seal portion 12c, inclined 90° with respect to the reference line C. Further, for the packaging container 2 of Comparative Example 4, the center in the longitudinal direction of the processed portion 12a was set as the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0050] The packaging container 2 of Comparative Example 5 formed a processed portion 12a within the inner peripheral edge of the seal portion 12c and on the reference line C, inclined 90° with respect to the reference line C. Further, for the packaging container 2 of Comparative Example 5, the center in the longitudinal direction of the processed portion 12a was set at a position shifted 20 mm from the center in the short-side direction of the inner peripheral edge of the seal portion 12c to one long-side.

[0051] The packaging container 2 of Comparative Example 6 formed a processed portion 12a within the inner peripheral edge of the seal portion 12c and on the reference line C, inclined 90° with respect to the reference line C. Further, for the packaging container 2 of Comparative Example 6, the center in the longitudinal direction of the processed portion 12a was set at a position shifted 30 mm from the center in the short-side direction of the inner peripheral edge of the seal portion 12c to one long-side.

[0052] The packaging container 2 of Comparative Example 7 was formed with a processed portion 12a that is within the inner peripheral edge of the seal portion 12c and inclined 90° with respect to the reference line C. Further, in the packaging container 2 of Comparative Example 7, the center in the longitudinal direction of the processed portion 12a was shifted 30 mm from the center in the short-side direction of the inner peripheral edge of the seal portion 12c to one long-side side, and was set at a position shifted 35 mm from the center in the longitudinal direction of the inner peripheral edge of the seal portion 12c to one short-side side.

[0053] Then, three samples of the packaging container 2 of each Example and each Comparative Example were formed. The packaging container 2 of each Example and each Comparative Example was placed in a constant temperature water bath set at 90°C using a seal tester (FKT-100J) manufactured by Sanken Science Co., Ltd., with the lid 12 immersed in the water surface. Then, a needle was inserted from the bottom of the container body 11 to inject air into the packaging container 2, and the opening pressure (kPa) at the fracture portion 12b of the processed portion 12a was measured respectively.

[0054] [Results of Evaluation Test 1] The opening pressure P (kPa) of the fracture portion 12b measured three times in each Example and each Comparative Example is described for reference in each example of FIG. 4. The opening pressure in FIG. 4 is the pressure value when at least any one of the three fracture portions 12b has broken. As shown in FIG. 4, the opening pressures P (kPa) of the fracture portion 12b measured three times in Example 1 were 8 kPa, 8.5 kPa, and 8 kPa. The opening pressures P (kPa) measured three times in Example 2 were 8 kPa, 8 kPa, and 8 kPa. The opening pressures P (kPa) measured three times in Example 3 were 9 kPa, 8.5 kPa, and 8.5 kPa. The opening pressures P (kPa) measured three times in Example 4 were 9 kPa, 9 kPa, and 9 kPa. The opening pressures P (kPa) measured three times in Example 5 were 8.5 kPa, 8.5 kPa, and 9 kPa. The opening pressures P (kPa) measured three times in Example 6 were 10 kPa, 10 kPa, and 9.5 kPa.

[0055] The opening pressures P (kPa) measured three times for Comparative Example 1 were 11 kPa, 10.5 kPa, and 10 kPa. The opening pressures P (kPa) measured three times for Comparative Example 2 were 11 kPa, 10.5 kPa, and 10.5 kPa. The opening pressures P (kPa) measured three times for Comparative Example 3 were 12 kPa, 12 kPa, and 12 kPa. The opening pressures P (kPa) measured three times for Comparative Example 4 were 11.5 kPa, 11.5 kPa, and 11 kPa. The opening pressures P (kPa) measured three times for Comparative Example 5 were 12 kPa, 12.5 kPa, and 12 kPa. The opening pressures P (kPa) measured three times for Comparative Example 6 were 13 kPa, 13 kPa, and 12.5 kPa. The opening pressures P (kPa) measured three times for the breaking part 12b of Comparative Example 7 were 12 kPa, 12 kPa, and 11.5 kPa.

[0056] As is clear from these results, the opening pressure P of the packaging container 2 of Example 1 to the packaging container 2 of Example 6 was P ≤ 11 kPa, while the opening pressure P of the packaging container 2 of Comparative Example 1 to the packaging container 2 of Comparative Example 7 was P ≥ 11 kPa. As is clear from the opening pressure P, for the packaging container 2 of Example 1 to the packaging container 2 of Example 5, the processing part 12a has the longitudinal direction of the processing part 12a ranging from the short side direction of the inner periphery of the seal part 12c to the diagonal line of the seal part 12c with respect to the short side direction, and at least a part of the processing part 12a is arranged in the range of 60% from the center of the long side (longitudinal direction) of the inner periphery of the seal part 12c to the short side. By doing so, it became clear that the internal pressure required for the opening (breaking) of the breaking part 12b can be reduced, and the breaking of the breaking part 12b can be easily and surely performed.

[0057] [Evaluation Test 2] Next, as Evaluation Test 2, analysis was performed on models of the packaging containers 2 of Example 7 and Example 9 below, and the packaging containers 2 of Comparative Example 8 and Comparative Example 9. The model analysis was performed using LS-DYNA manufactured by Ansys. As analysis conditions, the thickness t1 of the packaging container 2 was set to 0.50 mm and the elastic modulus was set to 1300 MPa. Among the thickness t2 of the lid 12, the thickness of the processed portion 12a was set to 0.05 mm and the elastic modulus was set to 15 MPa, and the thickness of the portion other than the processed portion 12a (non-processed portion) of the lid 12 was set to 0.05 mm and the elastic modulus was set to 1600 MPa. Further, the longitudinal length W1 of the flange 23 of the container body 11 of the packaging container 2 and the lid 12 was set to 149.4 mm, the lateral length W2 of the flange 23 and the lid 12 was set to 112.9 mm, the longitudinal length W3 at the inner peripheral edge of the seal portion 12c of the lid 12 was set to 135.1 mm, and the lateral length W4 at the inner peripheral edge of the seal portion 12c was set to 98.6 mm. Further, for the processed portion 12a, four portions 12a1 having a longitudinal length of 11 mm and a width of 0.5 mm were arranged along the longitudinal direction, and the interval between adjacent portions 12a1 was set to 1.0 mm.

[0058] Further, the packaging container 2 of Example 7, similar to the packaging container 2 of Example 1, had a processed portion 12a along the reference line C within the inner peripheral edge of the seal portion 12c and on the reference line C. Further, for the packaging container 2 of Example 7, the longitudinal center of the processed portion 12a was set to the lateral center of the inner peripheral edge of the seal portion 12c.

[0059] Further, the packaging container 2 of Example 8, similar to the packaging container 2 of Example 2, had a processed portion 12a along the reference line C within the inner peripheral edge of the seal portion 12c and on the reference line C. Further, for the packaging container 2 of Example 8, the longitudinal center of the processed portion 12a was set at a position shifted 20 mm from the lateral center of the inner peripheral edge of the seal portion 12c toward one long side.

[0060] In addition, for the packaging container 2 of Example 9, a processed portion 12a was set within the inner peripheral edge of the seal portion 12c and along the diagonal line of the seal portion 12c. Specifically, the processed portion 12a is inclined at 55.1° with respect to the reference line C as the angle in the posture along the diagonal line. For the packaging container 2 of Example 9, the center in the longitudinal direction of the processed portion 12a was set on the reference line C and at the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0061] Similar to the packaging container 2 of Comparative Example 1, for the packaging container 2 of Comparative Example 8, a processed portion 12a along the reference line C was set within the inner peripheral edge of the seal portion 12c and at a position shifted by 55 mm from the reference line C to one short-side of the inner peripheral edge of the seal portion 12c. Also, for the packaging container 2 of Comparative Example 8, the center in the longitudinal direction of the processed portion 12a was set at the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0062] Similar to the packaging container 2 of Comparative Example 3, for the packaging container 2 of Comparative Example 9, a processed portion 12a inclined at 90° with respect to the reference line C was set within the inner peripheral edge of the seal portion 12c and on the reference line C. Also, for the packaging container 2 of Comparative Example 9, the center in the longitudinal direction of the processed portion 12a was set at the center in the short-side direction of the inner peripheral edge of the seal portion 12c.

[0063] Then, a part of the container body 11 of the packaging containers 2 of Examples 7 to 9, Comparative Example 8, and Comparative Example 9 was fixed, and the internal pressure was increased at 300 kPa / s. Then, the maximum value of the stress generated in the breaking portion 12b, that is, between the portions 12a1 of the processed portion 12a was plotted.

[0064] Also, the maximum principal stress σ (MPa) when the pressure P inside the packaging container 2 is 10 kPa and the elongation δ (mm) in the short-side direction orthogonal to the longitudinal direction of the portion 12a1 of the processed portion 12a were determined.

[0065] [Results of Evaluation Test 2] The results of Evaluation Test 2 will be described below with reference to FIGS. 5 to 11. FIG. 5 is a graph showing the relationship between the pressure (kPa) inside the packaging container 2 and the stress (Mpa) at the fracture part 12b. FIG. 6 is an explanatory diagram showing the stress distribution of the lid 12 and the maximum principal stress of the processed part 12a when the pressure P inside the packaging containers 2 of Examples 7 to 9 is 10 kPa. FIG. 7 is an explanatory diagram showing the stress distribution of the lid 12 and the maximum principal stress of the processed part 12a when the pressure P inside the packaging containers 2 of Comparative Examples 8 and 9 is 10 kPa. FIG. 8 is an explanatory diagram showing the deformation of the processed part 12a and the stress distribution in the processed part 12a when the pressure P inside the packaging containers 2 of Examples 7 to 9 is 10 kPa. FIG. 9 is an explanatory diagram showing the deformation of the processed part 12a and the stress distribution in the processed part 12a when the pressure P inside the packaging containers 2 of Comparative Examples 8 and 9 is 10 kPa. FIG. 10 is an explanatory diagram showing the deformation of one fracture part 12b of the processed part 12a and the stress distribution at the fracture part 12b when the pressure P inside the packaging containers 2 of Examples 7 to 9 is 10 kPa. FIG. 11 is an explanatory diagram showing the deformation of one fracture part 12b of the processed part 12a and the stress distribution at the fracture part 12b when the pressure P inside the packaging containers 2 of Comparative Examples 8 and 9 is 10 kPa.

[0066] As shown in FIG. 5, in the packaging container 2 of Example 7, the highest stress occurred at the fracture part 12b, followed by the packaging containers of Example 8 and Example 9, and then the packaging containers 2 of Comparative Example 8 and Comparative Example 9. From this, it can also be seen that by making the processed part 12a of the present embodiment, suitable stress is generated in the processed part 12a due to the increase in the internal pressure of the packaging container 2, so that the fracture of the fracture part 12b is improved.

[0067] Also, as shown in FIGS. 6 to 11, in the packaging container 2 of Example 7, the maximum principal stress σ was 404.5 MPa, and the maximum elongation δ in the short direction of the portion 12a1 of the processed part 12a was 0.8 mm.

[0068] In the packaging container 2 of Example 8, the maximum principal stress σ was 337.8 MPa, and the maximum elongation δ in the short direction of the portion 12a1 of the processed portion 12a was 0.6 mm.

[0069] In the packaging container 2 of Example 9, the maximum principal stress σ was 280.7 MPa, and the maximum elongation δ in the short direction of the portion 12a1 of the processed portion 12a was 0.43 mm.

[0070] On the other hand, in the packaging container 2 of Comparative Example 8, the maximum principal stress σ was 192.9 MPa, and the maximum elongation δ in the short direction of the portion 12a1 of the processed portion 12a was 0.15 mm.

[0071] Also, in the packaging container 2 of Comparative Example 9, the maximum principal stress σ was 156.6 MPa, and the maximum elongation δ in the short direction of the portion 12a1 of the processed portion 12a was 0.27 mm.

[0072] In the packaging containers 2 of Examples 7 to 9, it was clarified that the maximum principal stress σ and the elongation δ in the processed portion 12a were larger than those of the lids 12 of Comparative Examples 8 and 9. Thus, also from the analysis results, by making the processed portion 12a of the present embodiment, suitable stress is generated in the processed portion 12a due to the increase in the internal pressure of the packaging container 2, and it can be seen that the breakage of the breakage portion 12b becomes good.

[0073] As described above, according to the lid 12 (film 3) used for the packaging container 1 containing the content according to the present embodiment, when the internal pressure of the packaging container 2 increases, the breakage portion 12b breaks suitably, so that the vapor can be discharged stably.

[0074] Note that the present invention is not limited to the above-described embodiments. For example, in the above example, the packaging container 2 was described as being formed by sealing the lid 12 formed by the container body 11 and the film 3, but it is not limited thereto. For example, as shown in FIG. 12, the packaging container 1 containing the contents may be formed into a bag shape or a pouch shape as the packaging container 2A by bending a single film 3 and heat-sealing the edges, or by stacking two or more films 3 and heat-sealing the edges. When a plurality of films 3 are used for the packaging container 2A, the processing portion 12a is formed on any one of the films 3. Further, the packaging container 2 is heat-sealed in a rectangular frame shape that is long in one direction, or a seal portion 12c with three sides heat-sealed is formed, and the longitudinal direction of the processing portion 12a ranges from an angle along the short side of the inner peripheral edge of the seal portion 12c to an angle along the diagonal line of the seal portion 12c, and is provided within a range of 60% from the center in the longitudinal direction of the long side of the inner peripheral edge of the seal portion 12c. The packaging container 2 formed by welding one or more films 3 configured as described above, like the packaging container 2 having the container body 11 and the lid 12 described above, can stably discharge steam because the rupture portion 12b preferably ruptures when the internal pressure of the packaging container 2 rises.

[0075] Note that the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist thereof at the implementation stage. Also, the respective embodiments may be implemented in appropriate combinations, and in that case, the combined effects can be obtained. Furthermore, the above embodiments include various inventions, and various inventions can be extracted by combinations selected from the plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiments, if the problem can be solved and the effects can be obtained, the configuration with these constituent elements deleted can be extracted as an invention.

Explanation of Reference Numerals

[0076] 1... Packaging container with contents, 2, 2A... Packaging containers, 3... Film, 11... Container body, 12... Lid, 12a... Processing part, 12a1... Portion, 12b... Breaking part, 12c... Sealing part, 21... Barrel part, 21a... First side part, 21b... Second side part, 22... Bottom part, 23... Flange, 23a... Flange part, 23b... Skirt part, 23c... Hem part, 100... Contents.

Claims

1. A seal part that is sealed to a flange provided at an open end of a bottomed container body formed in a rectangular shape long in one direction, or that is overlapped and sealed in a rectangular frame shape long in one direction, and A linear processed part that forms a break part that breaks due to an increase in internal pressure, Comprising, The processed part is a film that follows a reference line along the short side of the inner peripheral edge of the seal part, or is inclined at an angle between the reference line and the diagonal line of the seal part.

2. The film according to claim 1, wherein the angle of the processed part is in the range of -30° to 30° with respect to the reference line.

3. The film according to claim 1, wherein the angle of the processed part is in the range of -10° to 10° with respect to the reference line.

4. At least a part of the processed part is arranged in a range of a distance up to 60% of the length from the center of the long side of the inner peripheral edge of the seal part to the short side of the inner peripheral edge of the seal part in the direction along the long side, The film according to claim 1.

5. A bottomed container body formed in a rectangular shape long in one direction, having an opening at one end in the axial direction, and having a flange provided at the opening, A lid formed of the film according to any one of claims 1 to 4, wherein the seal part is sealed to the flange, A packaging container comprising.

6. The packaging container according to claim 5, wherein the container body has a skirt portion extending toward the bottom direction at the peripheral edge of the flange and having a length of 3 mm to 15 mm in the axial direction of the container body.

7. The packaging container according to claim 6, wherein the container body has a hem portion extending outward from the outer peripheral edge of the skirt portion and having a length of 1.5 mm to 10 mm in a direction orthogonal to the axial direction of the container body.

8. The packaging container according to claim 5, Contents provided in the packaging container, A packaging container containing contents comprising.

9. A packaging container formed in a bag shape by overlapping the films according to any one of claims 1 to 4 and sealing them at the seal part.

10. The packaging container according to claim 9, Contents provided in the packaging container, A packaging container containing contents comprising.

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