Pouch

Abstract

To provide a pouch that can suppress the amount of retraction of the top seal during heating.SOLUTION: The pouch includes: a pair of overlapping sheet portions; a pair of side seal portions provided on both edges of the pair of sheet portions extending in the first direction and sealing the pair of sheet portions to form a housing space, at least one of the pair of side seal portions having a first seal portion located near a top portion and a second seal portion located near a bottom portion and separated from the first seal portion; and a vapor vent seal portion connecting the first and second seal portions. The vapor vent seal portion has a triangular shape with its top on the side of the container space and is symmetrical about a first imaginary line perpendicular to the first direction through the top. The area surrounded by the vapor vent seal portion is an unsealed area, and a through portion is formed in the unsealed area of at least one of the sheet portions of the pair of sheet portions.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pouch.

Background Art

[0002] As a pouch for containing contents (for example, food) and heating the contents, the pouches described in Patent Document 1 and Patent Document 2 are known. The pouch described in Patent Document 1 has a structure for releasing steam generated when the contents are heated. Specifically, the side seal portion (side seal portion) of the pouch has an overhanging portion that projects toward the accommodation space side. The inside of the overhanging portion is an unsealed area. When the contents are heated and steam is generated, the seal of the overhanging portion is peeled off. As a result, the space containing the contents and the unsealed area are connected, and steam is discharged from the unsealed area through the unsealed area as a steam vent.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Normally, a pouch supplier manufactures a pouch with an open top, and supplies the pouch to a content manufacturer who manufactures the contents. After the content manufacturer accommodates the contents in the supplied pouch, the top is sealed to seal the contents in the pouch.

[0005] Pouch suppliers manufacture pouches with a recommended seal strength for the top seal area, depending on the intended use of the pouch. However, as mentioned above, the final sealing of the top seal is performed by the contents manufacturer. Even if the contents manufacturer is informed of the recommended seal strength by the pouch supplier, there is a risk that the top seal may be sealed with a lower seal strength than recommended. If the top seal is sealed with a lower seal strength than recommended, it is conceivable that the top seal may peel off and some of the contents may spill out if the end user of the pouch heats it, for example, in a microwave oven.

[0006] Therefore, the present invention aims to provide a pouch capable of suppressing the amount of recession of the top seal portion when heated. [Means for solving the problem]

[0007] A pouch relating to one aspect of the present invention is a pouch having a storage space for storing contents between a bottom and a top opposite the bottom, comprising a pair of overlapping sheet portions and a pair of side seal portions provided on both edges extending in a first direction in the pair of sheet portions, and the pair of sheet portions being sealed to form the storage space, wherein at least one of the pair of side seal portions has a first seal portion located closer to the top and a second seal portion located closer to the bottom than the first seal portion and spaced apart from the first seal portion The sheet has a seal portion and a steam vent seal portion that connects the first seal portion and the second seal portion and protrudes toward the containment space to release steam. The steam vent seal portion has a triangular shape with its apex toward the containment space and is symmetrical with respect to a first imaginary line passing through the apex and perpendicular to the first direction. The area surrounded by the steam vent seal portion is an unsealed area, and in the unsealed area of ​​at least one of the pair of sheet portions, a through portion is formed that penetrates the at least one sheet portion in the thickness direction.

[0008] The above-described pouch has a roughly triangular steam vent seal and a perforation in the unsealed area. Therefore, when the pouch is heated, the steam generated inside the pouch can be discharged through the steam vent seal and the perforation. As a result, the internal pressure inside the pouch does not increase easily, and the amount of recession of the top seal can be suppressed.

[0009] The above-mentioned through-port has a first end and a second end opposite to the first end, and the region of the through-port other than the first end and the second end may be spaced apart with respect to a second imaginary line connecting the first end and the second end. In this case, even if steam escapes from the steam vent seal and the through-port while the pouch is being heated, the pouch is less likely to rotate.

[0010] The aforementioned through-hole may be arc-shaped. In this case, even if steam escapes from the steam vent seal and the through-hole while the pouch is being heated, the pouch is less likely to rotate.

[0011] At least a portion of the above-mentioned penetration may lie on the first imaginary line.

[0012] A portion of the above-mentioned penetration may be located on the side of the containment space that is greater than a third imaginary line, which is an imaginary extension of the edge of the first seal portion and the second seal portion that is closest to the containment space. In this case, even if steam escapes from the steam vent seal portion and the penetration portion while the pouch is being heated, the pouch is less likely to rotate.

[0013] The above-mentioned perforations may be formed in both of the pair of sheet portions. In this case, steam can escape more easily. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a pouch that can suppress the amount of recession of the top seal portion when heated. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a schematic diagram of an example of a pouch according to one embodiment, with the top open. [Figure 2]Figure 2 is a drawing schematically showing the pouch shown in Figure 1 with the top part closed. [Figure 3] Figure 3 is an end view taken along line III-III of Figure 2. [Figure 4] Figure 4 is an end view taken along line IV-IV of Figure 2. [Figure 5] Figure 5 is an enlarged view of the steam vent seal part shown in Figure 1. [Figure 6] Figure 6 is a drawing for explaining the through-hole shown in Figures 1 and 5. [Figure 7] Figure 7 is a plan view of the pouch of Example 1. [Figure 8] Figure 8 is an enlarged view of the vicinity of the through-hole of the pouch of Example 2. [Figure 9] Figure 9 is an enlarged view of the vicinity of the through-hole of the pouch of Example 3. [Figure 10] Figure 10 is an enlarged view of the vicinity of the through-hole of the pouch of Example 4. [Figure 11] Figure 11 is an enlarged view of the vicinity of the through-hole of the pouch of Example 5. [Figure 12] Figure 12 is an enlarged view of the vicinity of the through-hole of the pouch of Example 6. [Figure 13] Figure 13 is an enlarged view of the vicinity of the through-hole of the pouch of Example 7. [Figure 14] Figure 14 is an enlarged view of the vicinity of the through-hole of the pouch of Example 8. [Figure 15] Figure 15 is a plan view of the pouch of Comparative Example 1. [Figure 16] Figure 16 is an enlarged view of the steam vent seal part of the pouch shown in Figure 15. [Figure 17] Figure 十七 is a drawing showing the results of an evaluation experiment regarding the retreat amount of the top seal part.

Modes for Carrying Out the Invention

[0016] It should be noted that in the above translation, "Figure 十七" should be adjusted according to the actual correct figure number representation in the original text. Here, it seems there might be a mistake in the original text's figure number "十七". If it is supposed to be "17", then it should be translated as "Figure 17".Embodiments of the present invention will be described below with reference to the drawings. The same elements are denoted by the same reference numerals. Repetitive descriptions will be omitted. The dimensional ratios in the drawings do not necessarily correspond to those described.

[0017] Figure 1 is a schematic diagram of an example of a pouch 10 according to one embodiment, with the top open. Figure 2 is a schematic diagram of the pouch 10 shown in Figure 1 with the top closed. Figure 3 is an end view along line III-III in Figure 2. Figure 4 is an end view along line IV-IV in Figure 2.

[0018] The pouch 10 has a storage space S (see Figures 3 and 4) for containing contents 100 between the bottom 12 and the top 14 located on the opposite side of the bottom 12. The pouch 10 is a self-standing packaging bag known as a standing pouch. Hereinafter, the state in which the top 14 is open to contain the contents 100 will be referred to as the open state, and the state in which the top 14 is closed will be referred to as the closed state. The pouch 10 in the closed state is the pouch 10 that is provided to the end user.

[0019] The contents 100 are, for example, food. The contents 100 are, for example, liquid foods (such as curry, hamburgers, stew, soup, etc.). The pouch 10 is a packaging bag for cooking the contents 100 by heating it, for example, in a microwave oven.

[0020] For the sake of explanation, in the following, the top 14 side of the pouch 10 will be referred to as the "upper side," the bottom 12 side as the "lower side," the direction in which the side edge 10a (or side edge 10b) of the pouch 10 extends will be referred to as the vertical direction (first direction), and the direction perpendicular to the vertical direction will be referred to as the horizontal direction (or width direction). The vertical direction is also the direction perpendicular to the outer edge (base) of the bottom 12 or the outer edge (top) of the top 14.

[0021] Examples of the planar shape (shape viewed from the thickness direction) of pouch 10 are rectangles or squares. Examples of the vertical length L1 of pouch 10 are 100mm to 180mm, and examples of the horizontal length L2 are 100mm to 200mm.

[0022] The pouch 10 has a pair of overlapping sheet portions 16 and 18 (see Figures 3 and 4) and a sheet portion 20 (see Figure 1).

[0023] The pair of sheet sections 16 and 18 are the front sheet section (or first side sheet section) and the rear sheet section (or second side sheet section) of the pouch 10. The plan view shapes of the pair of sheet sections 16 and 18 correspond to the plan view shapes of the pouch 10. Sheet section 20 is a sheet section that constitutes the bottom 12 of the pouch 10.

[0024] Sheet portion 16, sheet portion 18, and sheet portion 20 are terms used to conveniently distinguish the front, back, and bottom portions of the pouch 10, respectively. Therefore, for example, sheet portion 16, sheet portion 18, and sheet portion 20 may each be a single sheet, or sheet portion 16, sheet portion 18, and sheet portion 20 may be formed from a single sheet.

[0025] The sheet portion 16, sheet portion 18, and sheet portion 20 include, for example, an outermost layer and a sealant layer (innermost layer).

[0026] The outermost layer has mechanical strength and heat resistance sufficient to prevent deformation during heat sealing. Examples of the outermost layer include a single polyester film, nylon film, or polypropylene film, or a laminate of two or more of these. An example of a polyester film is polyethylene terephthalate (PET) film. The outermost layer may also be a transparent vapor-deposited film. An example of a polypropylene film is biaxially oriented polypropylene film (OPP: Oriented Poly Propylene).

[0027] The sealant layer can be made from, for example, low-density polyethylene film, linear low-density polyethylene film, medium-density polyethylene film, high-density polyethylene film, polypropylene film, ethylene-α-olefin copolymer film, or ionomer film. A single layer or two or more layers of these films can be co-extruded.

[0028] Sheet sections 16, 18, and 20 may have an intermediate layer between the outermost layer and the sealant layer to improve the properties of the pouch 10, such as drop resistance and puncture resistance. The intermediate layer may be made of a material that has excellent tear resistance in the direction of resin flow, for example. Examples of intermediate layers include low-density polyethylene film, linear low-density polyethylene film, nylon film, polyester film, and polypropylene film.

[0029] In sheet portions 16, 18, and 20, patterns, product description text, etc., may be printed on at least one of the inner surface (the surface facing the innermost layer) of the outermost layer or on the front and back surfaces of the intermediate layer. In this case, it is preferable that the layer to which printing is applied is made of a material suitable for printing.

[0030] Multiple layers constituting sheet portion 16, sheet portion 18, and sheet portion 20 can be joined, for example, via an adhesive layer. An example of such an adhesive layer is a layer formed from an adhesive. Examples of adhesives that constitute the adhesive layer include liquid-curing urethane adhesives, polyester urethane adhesives, polyether urethane adhesives, acrylic adhesives, polyester adhesives, polyamide adhesives, and epoxy adhesives. When such adhesives are used, the two layers joined by the adhesive layer are laminated by dry lamination or non-solvent lamination. The adhesive layer may be a thermoplastic resin such as polyethylene resin or polypropylene resin. In this case, the two layers joined by the adhesive layer can be laminated by extrusion lamination.

[0031] The layer configurations of sheet section 16, sheet section 18, and sheet section 20 may be the same or different.

[0032] Sheet sections 16 and 18 are stacked so that their sealant layers face each other. Sheet section 20 is positioned on the bottom 12 side of the pouch 10 relative to sheet sections 16 and 18. Sheet section 20 is folded into a self-supporting shape (e.g., gusset shape) with the sealant layer facing outwards and is sandwiched between the stacked sheet sections 16 and 18. For example, sheet section 20 is folded in half with the sealant layer facing outwards and inserted between sheet sections 16 and 18. In the open state before the contents 100 are placed in the pouch 10, an example of the vertical length L3 of the folded sheet section 20 is 25 mm or more and 60 mm or less.

[0033] The pouch 10 is formed by heat-sealing sheet portions 16, 18, and 20. As shown in Figure 1, in the open state, the pouch 10 has a bottom seal portion 22 and a pair of side seal portions 26 and 28. As shown in Figure 2, the closed state of the pouch 10 further has a top seal portion 24. Therefore, the closed state of the pouch 10 has a bottom seal portion 22, a top seal portion 24, and a pair of side seal portions 26 and 28. In Figures 1 and 2, the sealed areas are hatched to clearly indicate the sealed areas. As will be described later, the top seal portion 24 is a seal portion formed after the contents 100 are placed in the open state of the pouch 10.

[0034] The bottom seal portion 22 is the portion where the sheet portion 20, which is inserted between the pair of sheet portions 16 and 18 as described above, and the sheet portions 16 and 18 are heat-sealed. An example of the sealing strength of the bottom seal portion 22 is 50 N / 15 mm or more and 80 N / 15 mm or less.

[0035] As shown in Figure 2, the top seal portion 24 is the portion of the pair of sheet portions 16 and 18 where the edge opposite to the bottom seal portion 22 (the top portion 14 side) is heat-sealed. The top seal portion 24 is formed by heat-sealing the top portion 14 side after the contents 100 have been placed in the open pouch 10. An example of the seal width (vertical length) W1 of the top seal portion 24 (or the area intended to become the top seal portion 24) is 5 mm to 25 mm. The seal strength of the top seal portion 24 is set according to the size of the pouch 10 and the conditions of the contents 100 (type of contents, amount, etc.), but the usual recommended seal strength is 50 N / 15 mm to 80 N / 15 mm.

[0036] The pair of side seal portions 26 and 28 are formed on both sides in the lateral direction of the overlapping sheet portions 16 and 18. The pair of side seal portions 26 and 28 connect the bottom seal portion 22 and the top seal portion 24.

[0037] Of the pair of side seal portions 26 and 28, side seal portion 26 is a seal portion located on the side edge 10a side of the pouch 10 in the lateral direction. The side seal portion 26 is formed by heat sealing the sheet portion 16 (or sheet portion 18) along the outer edge of the sheet portion 16 (or sheet portion 18). An example of the seal width W2 (lateral length) of the side seal portion 26 is 3 mm or more and 15 mm or less.

[0038] Of the pair of side seal portions 26 and 28, side seal portion 28 is a seal portion located opposite to side seal portion 26 in the lateral direction. The side seal portion 28 in this embodiment is configured to release steam generated when the pouch 10 is heated to the outside. Specifically, the side seal portion 28 has a first upper seal portion (first seal portion) 30, a first lower seal portion (second seal portion) 32, and a steam vent seal portion 34.

[0039] The first upper seal portion 30 is the portion of the side seal portion 28 located closer to the top portion 14. The first upper seal portion 30 is formed by heat sealing a pair of sheet portions 16 and 18 along the outer edge of the sheet portion 16 (or sheet portion 18). An example of the seal width W3 of the first upper seal portion 30 is the same as the example of the seal width W2 of the side seal portion 26. In this embodiment, the seal width W3 is the same as the seal width W2, but the seal width W3 may be different from the seal width W2. An example of the seal strength of the first upper seal portion 30 is 50 N / 15 mm or more and 80 N / 15 mm or less.

[0040] The first lower seal portion 32 is the portion of the side seal portion 28 that is located closer to the bottom portion 12 than the first upper seal portion 30. The first lower seal portion 32 is spaced apart from the first upper seal portion 30 in the longitudinal direction. Therefore, the region of the sheet portions 16 and 18 between the first lower seal portion 32 and the first upper seal portion 30 in the longitudinal direction is an unsealed region. The first lower seal portion 32 is formed by heat sealing a pair of sheet portions 16 and 18 along the outer edge of the sheet portion 16 (or sheet portion 18). An example of the seal width W4 of the first lower seal portion 32 is the same as the example of the seal width W2 of the side seal portion 26. An example of the seal strength of the first lower seal portion 32 may be the same as that of the first upper seal portion 30. The seal strength of the first lower seal portion 32 may be the same as or different from the seal strength of the first upper seal portion 30.

[0041] In this embodiment, the seal width W4 of the first lower seal portion 32 is the same as the seal widths W2 and W3, but the seal width W4 may be different from at least one of the seal widths W2 and W3. For example, the seal width W4 may be narrower than the seal width W3.

[0042] The steam vent seal portion 34 is a part provided in the side seal portion 28 to release steam generated when the pouch 10 is heated to the outside. The steam vent seal portion 34 is located closer to the top portion 14 than the area of ​​the containment space S that is filled with contents 100. The steam vent seal portion 34 is the part that connects the first upper seal portion 30 and the first lower seal portion 32 and protrudes toward the containment space S. Therefore, the side seal portion 28 has a recessed shape toward the containment space S in the area of ​​the steam vent seal portion 34.

[0043] In pouch 10, the area enclosed by the side edge 10b of pouch 10 and the steam vent seal portion 34 (including the area between the first upper seal portion 30 and the first lower seal portion 32) is an unsealed area 36 in which the sheet portion 16 and sheet portion 18 are not sealed. The portion of the unsealed area 36 that overlaps with the side edge 10b is open and functions as a steam vent 36a.

[0044] The steam vent seal portion 34 has a top portion 38 on the side facing the containment space S. The steam vent seal portion 34 is formed by heat sealing sheet portions 16 and 18 to the shape of the steam vent seal portion 34. In one embodiment, the seal strength of the steam vent seal portion 34 is smaller than the seal strength of the first upper seal portion 30, the first lower seal portion 32, and the side seal portion 26, so that steam can easily escape from the steam vent seal portion 34. An example of the seal strength of the steam vent seal portion 34 is 25 N / 15 mm or more and 50 N / 15 mm or less. In one embodiment, the seal width of the steam vent seal portion 34 may be narrower than the seal width W3 of the first upper seal portion 30 and the seal width W4 of the first lower seal portion 32.

[0045] The steam vent seal portion 34 will be further explained, mainly with reference to Figure 5. Figure 5 is an enlarged view of the steam vent seal portion 34. In Figure 5, the hatching applied to the sealing area in Figure 1, etc., has been omitted for the sake of readability. The steam vent seal portion 34 is a triangular (or roughly V-shaped) seal portion with a top portion 38 on the side of the containment space S. The steam vent seal portion 34 is symmetrical with respect to the first imaginary line VL1. The first imaginary line VL1 is an imaginary straight line that passes through the top portion 38 and extends laterally. An example of the length L4 between the outer edge of the top portion 14 (the upper edge of the pouch 10) and the first imaginary line VL1 is 25 mm or more and 70 mm or less.

[0046] The steam vent seal section 34 has a second upper seal section 40 connected to the first upper seal section 30 and a second lower seal section 42 connected to the first lower seal section 32. The connecting portion of the second upper seal section 40 and the second lower seal section 42 is the top section 38.

[0047] The second upper seal portion 40 is located on the top 14 side of the first imaginary line VL1. The second upper seal portion 40 has a first edge 401 on the side of the accommodating space S and a second edge 402 on the side of the unsealed area 36. In this embodiment, the seal width of the second upper seal portion 40 is substantially constant, but it may narrow towards the top 38, for example.

[0048] The second lower seal portion 42 is located on the opposite side of the second upper seal portion 40 with respect to the first virtual line VL1. The second lower seal portion 42 has a first edge 421 on the side of the accommodating space S and a second edge 422 on the side of the unsealed area 36. The second lower seal portion 42 is symmetrical with respect to the second upper seal portion 40 with respect to the first virtual line VL1. In this embodiment, the seal width of the second lower seal portion 42 is substantially constant, but it may narrow towards the top portion 38.

[0049] The second upper seal portion 40 and the second lower seal portion 42 are inclined with respect to the first imaginary line VL1 (or the side edge 10b or the vertical direction), and the steam vent seal portion 34 has a widening gap between the second upper seal portion 40 and the second lower seal portion 42 from the top portion 38 toward the side edge 10b. An example of the inclination angle θ1 of the second upper seal portion 40 (or the second lower seal portion 42) with respect to the first imaginary line VL1 is between 15 degrees and 45 degrees. The inclination angle θ1 can be the angle between the second edge 402 and the first imaginary line VL1.

[0050] An example of the length L5 between the end 401a of the first edge 401 of the second upper seal portion 40 and the end 421a of the first edge 421 of the second lower seal portion 42 is 5 mm or more and 55 mm or less. End 401a is the end of the first edge 401 on the side of the first upper seal portion 30 and is the contact point with the first upper seal portion 30. End 421a is the end of the first edge 421 on the side of the first lower seal portion 32 and is the contact point with the first lower seal portion 32.

[0051] An example of the length L6 between the end 402a of the second edge 402 of the second upper seal portion 40 and the end 422a of the second edge 422 of the second lower seal portion 42 is 5 mm or more and 55 mm or less. End 402a is the end of the second edge 402 on the side of the first upper seal portion 30 and is the contact point with the first upper seal portion 30. End 422a is the end of the second edge 422 on the side of the first lower seal portion 32 and is the contact point with the first lower seal portion 32.

[0052] The top 38 of the steam vent seal portion 34 may be rounded (in other words, it may have a curved surface) as shown in Figure 5. When the top 38 is rounded, an example of the radius of curvature of the edge of the top 38 on the side of the containment space S is 3 mm or more and 20 mm or less, and an example of the radius of curvature of the edge of the top 38 on the side of the unsealed area 36 is 1.5 mm or more and 10 mm or less. An example of the seal width W5 of the steam vent seal portion 34 at the position of the top 38 (seal width along the second imaginary line VL2 described later) is 1.5 mm or more and 5 mm or less. An example of the length L7 between the tip 38a of the steam vent seal portion 34 on the side of the containment space S (the end of the top 38 closest to the containment space S) and the side edge 10b is 5 mm or more and 20 mm or less.

[0053] In the unsealed area 36 surrounded by the steam vent seal portion 34, through portions 44 are formed that penetrate through the sheet portion 16 and the sheet portion 18 in the thickness direction (directions perpendicular to the vertical and horizontal directions). The through portions 44 can be formed, for example, by making cuts (or slits) in the sheet portion 16 and the sheet portion 18 with a blade having the shape of the through portion 44, or by cutting out the sheet portion 16 and the sheet portion 18.

[0054] The through-hole 44 will be explained using Figure 6. The through-hole 44 has a first end 441 and a second end 442. The second end 442 is the end opposite to the first end 441. The through-hole 44 may satisfy at least one of the following conditions (1) to (5).

[0055] Condition (1): The penetration portion 44 is not linear. The non-linear through-section 44 has curved or angular portions. In other words, the through-section 44 has a shape in which there is a gap between the second imaginary line VL2 and the region of the through-section 44 between the first end 441 and the second end 442 and the second imaginary line VL2. The second imaginary line VL2 is an imaginary straight line connecting the first end 441 and the second end 442, as shown in Figure 6.

[0056] An example of a non-linear through-hole 44 is an arc-shaped through-hole. Examples of arc shapes include circular arcs, semicircular shapes, or crescent shapes as shown in Figure 6. The through-hole 44 may also be U-shaped (or U-shaped) or V-shaped. An example of the radius of curvature of an arc-shaped through-hole 44 is between 2.5 mm and 10 mm.

[0057] An example of the length L8 between the first end 441 and the second end 442 is between 3.5 mm and 14 mm. Length L8 is the length along the second virtual line VL2.

[0058] Condition (2): A portion of the penetration 44 lies on the first virtual line VL1 passing through the top 38 (specifically, the tip 38a) of the steam vent seal portion 34. That is, the penetration 44 has at least one intersection with the first virtual line VL1.

[0059] Condition (3): A portion of the through-hole 44 is located on the side of the housing space S beyond the third virtual line VL3, which is an extension of the edge of the first upper seal portion 30 and the first lower seal portion 32 that is closest to the housing space S. Specifically, a portion of the through-hole 44 is located on the side of the housing space S beyond the third virtual line VL3, which is an extension of the edge of the inner edge 301 of the first upper seal portion 30 on the housing space S side and the inner edge 321 of the first lower seal portion 32 that is closer to the housing space S side. In the configuration shown in Figure 6, the extension of the inner edge 301 and the extension of the inner edge 321 coincide, so the third virtual line VL3 is an extension of the inner edge 301 (or inner edge 321).

[0060] Condition (4): The penetration portion 44 is located within the similar region 37 enclosed by the dashed line in Figure 6. The similar region 37 is a region similar to the unsealed region 36 and is between one-quarter and two-thirds the area of ​​the unsealed region 36. Since the unsealed region 36 is triangular in shape, the similar region 37 is also triangular in shape and has a vertex 37a. The vertex 37a is located on the first imaginary line VL1. In the similar region 37, the base opposite the vertex 37a may coincide with the side edge 10b, or it may be separated from the side edge 10b.

[0061] Condition (5): The through-section 44 is formed such that the imaginary line extending from the first end 441 or the second end 442 to the through-section 44, or the tangent at the position of the first end 441 or the second end 442, does not extend below the second imaginary line VL2 and toward the accommodation space S. The imaginary line extending from the first end 441 to the through-section 44 is an imaginary line extending from the first end 441 to the through-section 44 along the through-section 44 extending from the second end 442 to the first end 441, and as shown in Figure 6, if the through-section 44 is arc-shaped, it is an extension of the arc. Similarly, the imaginary line extending from the second end 442 to the through-section 44 is an imaginary line extending from the second end 442 to the through-section 44 along the through-section 44 extending from the first end 441 to the second end 442.

[0062] The through-section 44 will be further explained using the through-section 44 shown in Figure 6 as an example. The through-section 44 shown in Figure 6 is an example of a case that satisfies all of conditions (1) to (5). The through-section 44 shown in Figure 6 is formed such that the second imaginary line VL2 passes through the end 422a, and together with θ2 (described later), it forms an angle θ2 with the side edge 10b (or vertical direction). An example of angle θ2 is between +10 degrees and +45 degrees. In this embodiment, angle θ2 is defined as "positive" when counterclockwise with respect to the vertical direction (the direction of extension of the side edge 10b) and "negative" when clockwise. For example, in the configuration shown in Figure 6, if the absolute value of angle θ2 is 25 degrees, then angle θ2 is +25 degrees.

[0063] In the through-hole 44 shown in Figure 6, the first end 441 is spaced apart from the second edge 402. An example of the length L9a (length along the second imaginary line VL2) between the first end 441 and the second edge 402 is between 0.5 mm and 6 mm.

[0064] As mentioned above, the through-hole 44 shown in Figure 6 is just one example. Therefore, the arrangement of the through-hole 44 is not limited to the configuration shown in Figure 6.

[0065] In one embodiment, a notch n may be formed near the top seal portion 24 in at least one of the pair of side seal portions 26 and 28, as shown in Figures 1 and 2. The notch n is an opening for opening the pouch 10 after heating the contents 100.

[0066] The above pouch 10 can be manufactured, for example, as follows:

[0067] A pair of sheet portions 16 and 18 are overlapped so that their sealant layers face each other. A sheet portion 20, folded to a self-supporting shape with the sealant layer facing outwards, is sandwiched between the overlapping sheet portions 16 and 18, as described above. In this state, the sheet portions 16, 18, and 20 are heat-sealed to form a bottom seal portion 22 and a pair of side seal portions 26 and 28. Subsequently, a through portion 44 is formed in the unsealed area 36 on the side of the side seal portion 28. This results in an open pouch 10.

[0068] In the open pouch 10, the top 14 is open. Therefore, the contents 100 are placed into the storage space S through this opening. After that, the top 14 is heat-sealed to form the top seal portion 24. This results in a closed pouch 10.

[0069] The process of forming the through portion 44 is not limited to after the bottom seal portion 22 and the pair of side seal portions 26 and side seal portions 28 have been formed as described above. The through portion 44 may be formed at any stage before the contents 100 are placed in the storage space S. For example, sheet portions 16 and 18 with the through portion 44 already formed may be prepared.

[0070] If the pouch 10 has a notch n, the notch n can be formed at any stage before the contents 100 are placed in the storage space S. For example, the pouch 10 may be manufactured by preparing sheet portions 16 and 18 with the notch n already formed on them.

[0071] Next, we will explain the effects and benefits of pouch 10.

[0072] When an end-user (consumer) purchases pouch 10 and consumes the contents 100 inside pouch 10, they heat pouch 10, for example, in a microwave oven. When the steam generated inside pouch 10 due to this heating increases the internal pressure, the triangular-shaped steam vent seal portion 34 peels off starting from its top portion 38. As a result, the unsealed area 36 and the containment space S become connected, and steam is discharged to the outside of pouch 10 through the unsealed area 36 (more specifically, from the steam vent 36a). In this case, depending on the increase in internal pressure of pouch 10, the steam vent 36a may become blocked or the steam passage of the steam vent 36a may become narrowed. Even in such cases, since pouch 10 has a through portion 44, steam can be discharged from the through portion 44. Therefore, it is possible to suppress an unnecessary increase in internal pressure during heating of pouch 10.

[0073] If the penetration is not formed in an unsealed area, the steam vent 36a may become blocked or narrowed, causing the internal pressure of the pouch to rise above what was anticipated during the pouch manufacturing process. When the internal pressure rises above expectations in this way, the seals other than the steam vent seal may peel off. The side seals and bottom seals are designed with sufficient seal strength during pouch manufacturing to prevent substantial setback even in the event of such a situation.

[0074] On the other hand, typically, the contents manufacturer purchases open pouches from a pouch supplier, places the contents inside the pouch, and then seals the top. In other words, the pouch supplier and the company that seals the top to form the top seal are different. The top is also sealed with the seal strength recommended by the pouch supplier, and the recommended seal strength is set so that even if the above situation occurs, the amount of peeling (retraction) of the top seal is kept below a certain range. However, there may be cases where the top is sealed with a seal strength lower than the recommended seal strength and lower than the range assumed by the pouch supplier. In this case, as described above, if the opening (steam vent) on the side edge of the pouch formed by the sealed area becomes blocked or narrowed, and the internal pressure of the pouch increases, the top seal may peel off, and the contents may spill out.

[0075] Furthermore, if the opening (steam vent) on the side edge of the pouch formed by the sealing area becomes narrowed, steam will forcefully escape from that opening. This can cause the pouch to rotate during heating, making its position unstable. As a result, there is a risk that the pouch may tip over during heating.

[0076] In contrast, with pouch 10, even if the steam vent 36a is blocked or the steam flow path in the steam vent 36a narrows, steam can be discharged from the through-hole 44. Therefore, as mentioned above, an unnecessary increase in the internal pressure of pouch 10 can be suppressed. As a result, even if the top portion 14 is sealed with a seal strength lower than the recommended seal strength, peeling (retraction) of the top seal portion 24 can be suppressed during heating of pouch 10, preventing the contents 100 from being blown out from the top portion 14. Furthermore, since steam can be released from the through-hole 44, rotation of pouch 10, as mentioned above, is less likely to occur, and the structure of pouch 10 also prevents the pouch 10 from tipping over during heating.

[0077] Furthermore, if the through-hole 44 satisfies at least one of the above conditions (1) and (3), the above rotation is less likely to occur.

[0078] If the penetration portion 44 satisfies the above condition (4), the penetration portion 44 is formed at a certain distance from the steam vent seal portion 34. In this case, even if a part of the sheet portion 16 (or sheet portion 18) near the penetration portion 44 breaks due to steam being discharged from the penetration portion 44, the break is unlikely to reach the steam vent seal portion 34, in particular, the area in the steam vent seal portion 34 where the seal state is maintained without peeling. As a result, it is possible to prevent the contents 100 from spilling out from the steam vent seal portion 34 and its vicinity.

[0079] If the penetration 44 satisfies the above condition (5), steam is discharged from the penetration 44, and even if a part of the sheet portion 16 (or sheet portion 18) near the penetration 44 ruptures, the rupture is less likely to progress toward the center of the containment space S or toward the contents 100. Therefore, even if the above-mentioned rupture occurs, it is possible to prevent the contents 100 from spilling out from the rupture site.

[0080] As described in this embodiment, in the configuration in which through-holes 44 are formed in both the sheet portion 16 and the sheet portion 18, steam can be released from the through-holes 44 formed in both the sheet portion 16 and the sheet portion 18. As a result, an unnecessary increase in internal pressure inside the pouch 10 can be suppressed. Furthermore, since steam is discharged from both the sheet portion 16 and the sheet portion 18, rotation is less likely to occur.

[0081] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and is intended to include the scope indicated by the claims, and all modifications within the meaning and scope equivalent to the claims.

[0082] Furthermore, the embodiments and modifications described herein can be combined with each other without departing from the spirit of the present invention. [Examples]

[0083] The present invention will be further described below using examples. The present invention is not limited to the examples described below. For convenience of explanation, the same reference numerals are used for components that are the same as those in the above embodiments, and redundant explanations are omitted.

[0084] [Example 1] As the pouch for Example 1, pouch 10A shown in Figure 7 was manufactured. Figure 7 is a diagram illustrating the pouch for Example 1. In Figure 7, as in Figures 1 and 2, hatching is applied to the sealed area to clearly indicate the sealed area. Pouch 10A corresponds to the pouch 10 shown in Figure 1 and had a vapor vent seal 34, an unsealed area 36, ​​and a through-hole 44 as illustrated in Figures 5 and 6.

[0085] To produce pouch 10A, sheet sections 16, 18, and 20 were prepared. Sheet sections 16, 18, and 20 were the same laminated sheet having the following layer configuration. <Layer configuration> Outer film / Printing layer / Interlayer film / Sealant layer The outer film was the outermost layer in the above layer configuration and was a 12 μm thick transparent vapor-deposited PET film (Toppan Printing Co., Ltd.: GL-ARH). The printed layer was formed using Riogran, manufactured by Toyo Ink Co., Ltd. The intermediate film was a 15 μm thick nylon film (manufactured by Toyobo Co., Ltd.: NAP22). The sealant layer was a 60 μm thick axially oriented polypropylene film (manufactured by Toray Film Processing Co., Ltd.: ZK207).

[0086] The sheet portions 16 and 18 were placed facing each other with the sealant layer facing inward, and sheet portion 20 was inserted between them to form the bottom portion 12 of pouch 10A. Sheet portions 16, 18, and 20 were then heat-sealed. At this time, the heat sealing was performed in such a way as to form a steam vent seal portion and an unsealed area as shown in Figure 1. Furthermore, the pouch 10A was manufactured by forming through portions 44 in sheet portions 16 and 18 with a cutter. Notches n were formed in the side seal portions 26 and 28 of pouch 10 at a position 20 mm from the outer edge of the top portion 14.

[0087] The dimensions of pouch 10A were as follows. As mentioned above, pouch 10A was similar to pouch 10 in the form shown in Figure 1, and had a steam vent seal portion 34 and a through portion 44, which were explained using Figures 5 and 6. Therefore, the explanation related to the steam vent seal portion 34 and the through portion 44 is based on Figures 5 and 6. (1) Dimensions of the outer shape of pouch 10A Vertical length L1: 158mm Horizontal length L2: 150mm Vertical length L3 of base 12: 42.5 mm Side seal section 26 seal width W2: 6mm The seal width W3 of the first upper seal portion 30 of the side seal portion 28 is 6 mm. The seal width W4 of the first lower seal portion 32 of the side seal portion 28 is 6 mm. (2) Dimensions of the steam vent seal section 34 (see Figure 5) Length L4 from the outer edge of the celestial part 14 to the second virtual line VL2: 48 mm Length L5 between end 401a and end 421a: 21 mm Length L6 between end 402a and end 422a: 20 mm Radius of curvature of the edge on the side S of the accommodating space at the top 38: 7 mm Radius of curvature of the edge on the unsealed area 36 side of the top portion 38: 3.5 mm Length L7 between the top 38 (tip 38a) and the side edge 10b: 17 mm The seal width W5 of the steam vent seal at the top 38 (tip 38a) is 2.5 mm. (3) Dimensions of the through-hole 44 (see Figure 6) Radius of curvature of through-hole 44: 5 mm Length L8 of end 441 and end 442: 7.07 mm

[0088] The through-hole 44 of the above size corresponds to 1 / 4 of the circumference of a circle with a radius of 5 mm. The through-hole 44 is positioned in the unsealed region 36 such that the first end 441 and the second end 442 are located on a second imaginary line VL2 through which the end 442a passes and the angle θ2 between the through-hole 44 and the side edge 10b (vertical direction) is +25 degrees, and the length L9a between the intersection of the second imaginary line VL2 and the second edge 402 and the first end 441 is 3 mm.

[0089] In pouch 10A, the seal strength of the side seal portion 26, the first upper seal portion 30, and the first lower seal portion 32 was 55 N / 15 mm, and the seal strength of the steam vent seal portion 34 was 35 N / 15 mm.

[0090] The through-hole 44 satisfied all of the conditions (1) to (5) described in the above embodiment.

[0091] [Pouch of Example 2] As the pouch for Example 2, pouch 10B was manufactured, which has the same configuration as pouch 10A except that the arrangement of the through-holes 44 is different from that of pouch 10A, as shown in Figure 8. Figure 8 is a partially enlarged view of pouch 10B. The through-holes 44 of pouch 10B are formed in such a way that the through-holes 44 of pouch 10A are inverted with respect to the first imaginary line VL1. Therefore, the shape of the through-holes 44 (radius of curvature and length L8 (see Figure 6)) was the same as that of pouch 10A.

[0092] The through-hole 44 of pouch 10B was positioned in the unsealed region 36 such that the second virtual line VL2 passed through the end 402a, the angle θ2 between the side edge 10b and the second virtual line VL2 was -25 degrees, and the length L9b between the intersection of the second virtual line VL2 and the second edge 422 and the first end 441 was 3 mm. The through-hole 44 was positioned above the second virtual line VL2 and was convex toward the top 14.

[0093] The through-hole 44 of the pouch 10B satisfied all of the conditions (1) to (5) described in the above embodiment.

[0094] [Pouch of Example 3] As the pouch for Example 3, a pouch 10C was manufactured, which had the same configuration as pouch 10A except that the arrangement of the through-hole 44 was different from that of pouch 10A, as shown in Figure 9. Figure 9 is a partially enlarged view of pouch 10C. The shape of the through-hole 44 of pouch 10C (radius of curvature and length L8 (see Figure 6)) was the same as that of pouch 10A. The through-hole 44 of pouch 10C had its first end 441 and second end 442 located on the first imaginary line VL1 and was positioned below the first imaginary line VL1. Therefore, the through-hole 44 of pouch 10C was convex downwards. The length L10 between the second end 442 and the side edge 10b was 3 mm.

[0095] The through-hole 44 of the pouch 10C satisfied all of the conditions (1) to (5) described in the above embodiment.

[0096] [Pouch of Example 4] As the pouch for Example 4, a pouch 10D was manufactured, which had the same configuration as pouch 10A except that the arrangement of the through-hole 44 was different from that of pouch 10A, as shown in Figure 10. Figure 10 is a partially enlarged view of pouch 10D. The shape of the through-hole 44 of pouch 10D (radius of curvature and length L8 (see Figure 6)) was the same as that of pouch 10A. The through-hole 44 of pouch 10D was arranged as if the through-hole 44 of pouch 10C were inverted with respect to the first imaginary line VL1. Therefore, the through-hole 44 was positioned below the first imaginary line VL1.

[0097] The through-hole 44 of the pouch 10C satisfied conditions (1) to (4) described in the above embodiment.

[0098] [Pouch of Example 5] As Example 5, a pouch 10E was manufactured, which has the same configuration as pouch 10A except that the arrangement of the through-holes 44 is different from that of pouch 10A, as shown in Figure 11. Figure 11 is a partially enlarged view of pouch 10E. The shape of the through-holes 44 of pouch 10E (radius of curvature and length L8 (see Figure 6)) was the same as that of pouch 10A.

[0099] The first end 441 of the penetration 44 of pouch 10E was positioned at a distance L11 from the side edge 10b and at a distance L12 from the end 402a. The length L11 was the length along the transverse direction and was 9 mm. The length L12 was the length along the longitudinal direction and was 9 mm. The angle θ2 between the second imaginary line VL2 and the side edge 10b was +40 degrees. The penetration 44 of Pauli D was positioned below the second imaginary line VL2. Therefore, the penetration 44 was convex toward the containment space S.

[0100] The through-hole 44 of the pouch 10E satisfied all of the conditions (1) to (5) described in the above embodiment.

[0101] [Pouch of Example 6] As the pouch for Example 6, a pouch 10F was manufactured, which has the same configuration as pouch 10A except that the arrangement of the through-holes 44 is different from that of pouch 10A, as shown in Figure 12. Figure 12 is a partially enlarged view of pouch 10F. The shape of the through-holes 44 of pouch 10F (radius of curvature and length L8 (see Figure 6)) was the same as that of pouch 10A.

[0102] The through-hole 44 of pouch 10F was positioned such that it was the same as the through-hole 44 of pouch 10E, but inverted with respect to the first imaginary line VL1. Therefore, the angle θ2 between the second imaginary line VL2 and the side edge 10b was -45 degrees. The through-hole 44 of pouch 10E was positioned above the second imaginary line VL2.

[0103] The penetration portion 44 of pouch 10F satisfied conditions (1) to (4) described in the above embodiment.

[0104] [Pouch of Example 7] As the pouch for Example 7, pouch 10G was manufactured, which has the same configuration as pouch 10A except that the arrangement of the through-holes 44 is different from that of pouch 10A, as shown in Figure 13. Figure 13 is a partially enlarged view of pouch 10G. The shape of the through-holes 44 of pouch 10G (radius of curvature and length L8 (see Figure 6)) was the same as that of pouch 10A.

[0105] Pouch 10G was positioned so that the second virtual line VL2 was parallel to the side edge 10b. The length L13 (lateral length) between the second virtual line VL2 and the side edge 10b was 3 mm. The first end 441 was positioned at a length L14 from end 402a. The length L12 was the length along the longitudinal direction and was 6.5 mm. The center of the penetration 44 of pouch 10G was located on the first virtual line VL1. Pouch 10G was located on the side edge 10b side (outside) of the third virtual line VL3.

[0106] The through-hole 44 of pouch 10G satisfied conditions (1), (2), (4), and (5) described in the above embodiment.

[0107] [Pouch of Example 8] As the pouch for Example 8, pouch 10H was manufactured, which has the same configuration as pouch 10A except that the arrangement of the through-holes 44 is different from that of pouch 10A, as shown in Figure 14. Figure 14 is a partially enlarged view of pouch 10H. The shape of the through-holes 44 of pouch 10H (radius of curvature and length L8 (see Figure 6)) was the same as that of pouch 10A.

[0108] Pouch 10H was positioned such that the penetration portion 44 of pouch 10G was inverted relative to the second virtual line VL2. The penetration portion 44 of pouch 10H was also located on the side edge 10b side (outside) of the third virtual line VL3.

[0109] The penetration portion 44 of the pouch 10H satisfied conditions (1), (2), and (4) described in the above embodiment.

[0110] [Pouch of Comparative Example 1] As the pouch for Comparative Example 1, pouch 46, shown in Figure 15, was manufactured. Figure 15 is a diagram illustrating the pouch for Comparative Example 1. In the description of pouch 46, for the sake of clarity, the same reference numerals are used for elements that are the same as those described in the above embodiment or pouch 10A. Duplicate explanations are omitted.

[0111] Pouch 46 differed from pouch 10A in that the seal width of the side seal portion 26 was not uniform, the notch n was formed only on the side seal portion 26, it had a side seal portion 28A instead of a side seal portion 28, and it did not have a through portion 44.

[0112] Aside from the differences mentioned above, the structure of pouch 46 was the same as that of pouch 10A. Therefore, pouch 46 had sheet sections 16, 18, and 20 with the same layer configuration as pouch 10A. Furthermore, the vertical length L1, horizontal length L2, and vertical length L3 of the bottom section 12 were the same as those of pouch 10A. The following description of pouch 46 will focus on the differences mentioned above.

[0113] In the side seal portion 26, the seal width W2a from the outer edge of the top portion 14 to a position of length L15 (vertical length) was 8 mm. In the side seal portion 26, the seal width W2b from the position of length L16 (vertical length) from the outer edge of the top portion 14 to the bottom portion 12 was 6 mm. Length L16 was 52 mm. A step was formed between the area of ​​seal width W2a and the area of ​​seal width W2b.

[0114] The side seal portion 28A differs from the side seal portion 28 of pouch 10A (pouch 10) in that it has a steam vent seal portion 48 instead of a steam vent seal portion 34. That is, the side seal portion 28A had a first upper seal portion 30, a first lower seal portion 32, and a steam vent seal portion 48. The first upper seal portion 30 and the first lower seal portion 32 were the same as in the case of pouch 10A. Therefore, the seal width W3 of the first upper seal portion 30 and the seal width W4 of the first lower seal portion 32 were 6 mm.

[0115] The steam vent seal portion 48 will be explained using Figure 16. The steam vent seal portion 48 has a second lower seal portion 50 and a second upper seal portion 52. Figure 16 is an enlarged view of the steam vent seal portion of the pouch shown in Figure 15. In Figure 16, the hatching of the sealed area shown in Figure 15 has been omitted for the sake of readability. In the pouch 46 as well, the area surrounded by the steam vent seal portion 48 was an unsealed area 54.

[0116] As shown in Figure 16, the second lower seal portion 50 is the part connected to the first lower seal portion 32 and is oriented laterally. The length L17 between the lower edge of the second lower seal portion 50 and the outer edge of the top portion 14 was 58 mm. The seal width W6 of the second lower seal portion 50 was 3 mm.

[0117] The second upper seal portion 52 is the portion that connects the end of the second lower seal portion 50 on the side of the storage space S to the first upper seal portion 30. The connection portion (corner) between the second upper seal portion 52 and the second lower seal portion 50 was rounded. The radius of curvature of the edge of the connection portion on the side of the storage space S was 4.5 mm, and the radius of curvature of the edge on the side of the unsealed area 54 was 2 mm. The length L18 (lateral length) between the position of the edge of the connection portion on the side of the storage space S closest to the center of the pouch 46 and the inner edge 321 of the first lower seal portion 32 was 10 mm. The length L19 (lateral length) between the position of the edge of the connection portion on the side of the unsealed area 54 closest to the center of the pouch 46 and the inner edge 321 was 7 mm.

[0118] The second upper seal portion 52 has a first region 521 connected to the second lower seal portion 50 and a second region 522 connected to the first upper seal portion 30. At the connection between the second region 522 and the first upper seal portion 30, the length L20 (vertical length) between the connection point 522a on the housing space S side and the outer edge of the top portion 14 was 33.65 mm. The seal width W7 of the second region 522 at the position of the connection point 522a was 7.5 mm.

[0119] The first region 521 extends from the end of the second lower seal portion 50 on the side of the housing space S toward the first upper seal portion 30, and the first region 521 is inclined with respect to the lateral direction. The second region 522 is the region between the first region 521 and the first upper seal portion 30, and is also inclined with respect to the lateral direction. The angle of inclination of the second region 522 with respect to the lateral direction is smaller than the angle of inclination of the first region 521 with respect to the lateral direction. Therefore, the edge of the second upper seal portion 52 on the side of the housing space S has a bend point 52a, and the edge on the side of the unsealed region 54 has a bend point 52b. The length L21 (length in the vertical direction) between the bend point 52a and the connection point 522a was 0.65 mm. The length L22 between the bend point 52a and the inner edge 301 of the first upper seal portion 30 was 3.37 mm. The length L23 between the bend point 52b and the side edge 10b was 8.18 mm.

[0120] In pouch 46, the seal strength of the side seal portion 26, bottom seal portion 22, first upper seal portion 30, first lower seal portion 32, and steam vent seal portion 48 was the same as the seal strength of the corresponding portion in pouch 10A.

[0121] [Evaluation of the amount of recession (recess) of the top seal portion] Evaluation experiment I was conducted on the amount of retraction of the top seal portion for pouches 10A, 10B, and 46 of Example 1, Example 2, and Comparative Example. The method of evaluation experiment I will be described by referring to pouches 10A, 10B, and 46 simply as "pouches."

[0122] [Evaluation Experiment I] (a1) After placing 170g of curry into an open pouch, the top was heat-sealed to form a top seal. The seal width of the top seal (seal width W1 in Figure 2) was 9mm. At this time, the seal strength of the top seal was set to the following three levels, and pouches (pouches containing curry) with top seals of each level were prepared. Level 1:20N / 15mm Level 2: 30N / 15mm Level 3: 40N / 15mm The seal strengths shown at the three levels above were significantly lower than the recommended lower limit of 50 N / 15 mm for the seal strength of the top seal in this technical field. (a2) Pouches of each level with a top seal formed as described above were retorted (temperature: 120 degrees Celsius, time: 30 minutes) and left for 1 day. After that, the pouches were heated in a microwave oven at 600W for 80 seconds (microwave reheating). (a3) The amount of retraction of the top seal (amount of peeling from the containment space S side) was measured for each pouch after heating.

[0123] In evaluation experiment I, six pouches with a top seal of level 1 as described in (a1) above were prepared, and (a2) and (a3) ​​above were performed on each pouch. Similarly, six pouches with a top seal of level 2 as described in (a1) above were prepared, and (a2) and (a3) ​​above were performed on each pouch. Similarly, six pouches with a top seal of level 3 as described in (a1) above were prepared, and (a2) and (a3) ​​above were performed on each pouch.

[0124] The above evaluation experiment I was conducted on pouches 10A, 10B, and 46. The experimental results for pouch 10A are shown in Table 1, the experimental results for pouch 10B are shown in Table 2, and the experimental results for pouch 46 are shown in Table 3. In Tables 1, 2, and 3, No. 1 to No. 6 are numbers used to distinguish the six pouches, and the average value is the average of the results for No. 1 to No. 6. [Table 1] [Table 2] [Table 3]

[0125] Figure 17 is a bar graph showing the average values ​​from Tables 1 to 3 above.

[0126] From Tables 1 to 3 and Figure 17, it can be seen that the amount of setback is reduced in Examples 1 and 2 compared to Comparative Example 1. Furthermore, as shown in Table 3, in Comparative Example 1, the amount of setback was 9 mm, and in some cases, the top seal portion was completely peeled off. In contrast, the maximum setback in Example 1 was 4 mm, and in Example 2, the maximum setback was 3.5 mm. In other words, in Examples 1 and 2, there were no cases where the top seal portion was completely peeled off. Therefore, it can be seen that by providing a triangular steam vent seal portion and forming a penetration in the unsealed area, it is possible to suppress the setback of the top seal portion even if the seal strength of the top seal portion is lower than the recommended seal strength.

[0127] [Evaluation of rotation during pouch heating] Evaluation Experiment II was conducted on pouches 10A to 10H from Examples 1 to 8 to evaluate the rotation state of the pouches when they were heated. The method of Evaluation Experiment II will be explained by referring to pouches 10A to 10H simply as "pouches." [Evaluation Experiment II] (b1) After placing 100g of water in an open pouch, the top was heat-sealed to form a top seal. The seal width of the top seal (seal width W1 in Figure 2) was 9mm, and the seal strength of the top seal was 30N / 15mm. (b2) The pouch with the top seal formed as described above was heated in a microwave oven at 1800W for 1 minute. The rotation of the pouch during heating was observed and the number of rotations was counted.

[0128] In evaluation experiment II, five pouches were prepared as described in (b1) above, and (b2) above was performed on each pouch.

[0129] The above evaluation experiment II was conducted on pouches 10A through 10H and pouch 56, respectively. The results of evaluation experiment II are shown in Table 4. Numbers 1 through 5 in Table 4 are used to distinguish the five pouches, and the average value is the average of the results (rotation speed) for numbers 1 through 5. [Table 4]

[0130] As a result of conducting the above evaluation experiment II on pouches 10A to 10H of Examples 1 to 8, as shown in Table 4, an average rotation speed of 3 rotations or less was achieved in Examples 1 to 8.

[0131] Therefore, it can be understood that by forming a through-hole in the unsealed area, steam can be properly discharged during heating of the pouch, and rotation of the pouch during heating can be suppressed. In particular, in Examples 1 to 6, where the arrangement of the through-holes satisfied condition (3) described in the above embodiment, rotation was less likely than in Examples 7 and 8, where the arrangement of the through-holes did not satisfy condition (3). Therefore, it can be understood that by forming the through-holes to satisfy at least the above condition (3), rotation can be further suppressed, that is, the pouch remains stable during heating. Furthermore, in Examples 1 to 6, an average rotation speed of 1 rotation or less was achieved, and in Examples 1, 2 and 5, an average rotation speed of less than 0.5 rotations was achieved. In other words, it can be understood that in Examples 1 to 6, and especially in Examples 1, 2 and 5, it is possible to further stabilize the pouch during heating. [Explanation of Symbols]

[0132] 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H...pouch, 10a...side edge, 10b...side edge, 12...bottom, 14...top, 16...sheet section, 18...sheet section, 20...sheet section, 22...bottom seal section, 26...side seal section, 28...side seal section, 24...top seal section, 30...first upper seal section (first seal section), 32...first lower seal section (second seal section), 34...steam vent seal section, 36...unsealed area, 38...top, 44...penetration section, 100...contents, 441...first end, 442...second end, S...containment space, VL1...first virtual line, VL2...second virtual line, VL3...third virtual line.

Claims

1. A pouch having a storage space for containing contents between the bottom and the top opposite the bottom, A pair of overlapping sheet sections, The pair of sheet portions are provided on both edges extending in the first direction, and the pair of sheet portions are sealed to form the accommodation space, Equipped with, At least one of the pair of side seal portions is The first seal portion located near the top, A second seal portion is located closer to the bottom than the first seal portion and spaced apart from the first seal portion, It has a steam venting seal portion that connects the first seal portion and the second seal portion and protrudes toward the containment space side for releasing steam, The steam venting seal portion has a triangular shape with its apex facing the containment space, and is symmetrical with respect to a first imaginary line passing through the apex and perpendicular to the first direction. The area surrounded by the aforementioned steam vent seal is an unsealed area. In the unsealed region of at least one of the pair of sheet portions, a through portion is formed that penetrates the at least one sheet portion in the thickness direction. The through portion has a first end and a second end opposite to the first end. With respect to the second imaginary line connecting the first end and the second end, the region of the penetration portion between the first end and the area other than the second end is separated. The angle between the second imaginary line and the side edge of the sheet portion on the side where the through portion is formed is within the range of -45 degrees or more and -25 degrees or more and 25 degrees or more and 40 degrees, when counterclockwise is considered a positive angle and clockwise is considered a negative angle with respect to the extending direction of the side edge. Pouch.

2. The aforementioned through portion has an arc shape. The pouch according to claim 1.

3. The through portion has an arc shape corresponding to one-quarter of the circumference, The pouch according to claim 2.

4. At least a portion of the penetration is on the first dashed line, A pouch according to any one of claims 1 to 3.

5. A portion of the through-hole is located on the side of the housing space that is greater than a third imaginary line, which is an imaginary extension of the edge of the first seal portion and the second seal portion that is closest to the housing space. A pouch according to any one of claims 1 to 4.

6. The through-holes are formed in both of the pair of sheet portions. The pouch according to claim 1.

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