Pouch

Abstract

To provide a pouch that can safely heat a content even under high output.SOLUTION: A pouch according to one embodiment is a pouch having a storage space for storing a content, and includes a pair of sheets and a pair of side seal parts sealed so that the pair of sheets form the storage space. At least one side seal part of the pair of side seal parts includes a first seal part located closer to a top part, a second seal part located closer to a bottom part and separated from the first seal part, and a steam venting seal part that connects the first and second seal parts and projects into the storage space to vent steam. The part formed by a first region between the first and second seal parts and a second region surrounded by the first region and the steam venting seal part is an unsealed region. In the unsealed region of at least one sheet, a penetrating part is formed to penetrate the at least one sheet in the thickness direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pouch.

Background Art

[0002] As a pouch for containing contents (e.g., food) and heating the contents, the pouch described in Patent Document 1 is known. The pouch described in Patent Document 1 has a structure for discharging steam generated when the contents are heated. Specifically, the side seal portion (side seal portion) of the pouch has an overhanging portion that protrudes 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 the steam is discharged from the unsealed area through the unsealed area as a steam vent.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When heating a pouch in a convenience store or the like, for example, the pouch may be heated with high-power (e.g., 1000 W or more) microwaves using a commercial microwave oven. When the pouch is heated under high power in this way, since the contents are rapidly heated, the speed of increase in the internal pressure of the accommodation space becomes fast. Therefore, even if an overhanging portion for discharging steam is provided as described in Patent Document 1, the pouch rapidly expands due to the rapid increase in the internal pressure, so there is a risk that the unsealed area will be blocked. If the unsealed area is blocked, the steam cannot be discharged, so there is a risk that the pouch will burst, or the seal other than the seal portion for steam venting will be peeled off and the contents will fly out of the pouch.

[0005] Therefore, the present invention aims to provide a pouch that can safely heat its contents even under high power (for example, 1000W or more). [Means for solving the problem]

[0006] The pouch according to 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 sheets and a pair of side seal portions provided on both sides of the pair of sheets and sealed so that the pair of sheets 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, a second seal portion located closer to the bottom than the first seal portion and spaced apart from the first seal portion, and a steam vent seal portion connecting the first seal portion and the second seal portion and protruding toward the storage space to release steam, wherein the portion formed by a first region between the first seal portion and the second seal portion and a second region surrounded by the first region and the steam vent seal portion is an unsealed region, and in the unsealed region of at least one of the pair of sheets, a through portion is formed that penetrates the at least one sheet in the thickness direction.

[0007] In the pouch with the above configuration, there is a perforation in the unsealed area. In this case, even if the internal pressure of the pouch increases rapidly due to high-power heating, for example, the perforation functions as a steam vent to release steam. Therefore, the pouch can be safely heated even under high power.

[0008] The perforations may be formed in both of the pair of sheets described above. In this case, steam can escape more easily even when the pouch is heated under high power.

[0009] At least a portion of the above-mentioned penetration portion may be located on the side of the housing space side of a first imaginary line that is an imaginary extension of the edge of the first seal portion and the second seal portion that is located closest to the housing space. In this case, bending of the first seal portion, the second seal portion, etc. can be prevented.

[0010] The shape of the through-hole as viewed from the thickness direction may be an arc that curves toward the center of the containment space. In this case, steam can be easily released from the through-hole.

[0011] The steam venting seal portion may have its tip at the position closest to the center of the containment space, and the through-hole may be located on a second imaginary line connecting the center of the containment space and the tip. In this case, steam can be easily vented from the through-hole.

[0012] The portion of the penetration closest to the center of the accommodation space may be located on the second imaginary line. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a pouch that can safely heat its contents even under high power. [Brief explanation of the drawing]

[0014] [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 schematic diagram showing the pouch shown in Figure 1 with the top closed. [Figure 3] Figure 3 is an end view along the line III-III in Figure 2. [Figure 4] Figure 4 is an end view along the line IV-IV in Figure 2. [Figure 5] Figure 5 is an enlarged view of the area near the steam vent seal. [Figure 6] Figure 6 is a plan view of the basic pouch configuration used in the experiment. [Figure 7]FIG. 7 is an enlarged view of the vicinity of the steam vent seal portion in the pouch shown in FIG. 6. [Figure 8] FIG. 8 is a drawing for explaining the position of the through portion changed in the experiment. [Figure 9] FIG. 9 is a drawing for explaining a modified example of the through portion.

MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same elements are denoted by the same reference numerals. Redundant descriptions are omitted. The dimensional ratios in the drawings do not necessarily match those in the description.

[0016] FIG. 1 is a schematic drawing of an example of a pouch 10 according to an embodiment in a state where the top portion is open. FIG. 2 is a drawing schematically showing the pouch 10 shown in FIG. 1 in a state where the top portion is closed. FIG. 3 is an end view taken along line III-III of FIG. 2. FIG. 4 is an end view taken along line IV-IV of FIG. 2.

[0017] The pouch 10 has an accommodation space S (see FIGS. 3 and 4) for accommodating the content 100 between the bottom portion 12 and the top portion 14 located on the opposite side of the bottom portion 12. The pouch 10 is a self-standing packaging bag known as a standing pouch. Hereinafter, a state where the top portion 14 is open for accommodating the content 100 is referred to as an open state, and a state where the top portion 14 is closed is referred to as a closed state. The pouch 10 in the closed state is the pouch 10 provided to the end user.

[0018] The content 100 is, for example, food (such as curry, hamburger, soup, etc.). The pouch 10 is a packaging bag for cooking the content 100 by heating it, for example, in a microwave oven. The pouch 10 is preferably used when heating the pouch 10 with a high output range of 1000 W or more, for example.

[0019] Hereinafter, for convenience of explanation, the direction orthogonal to the outer edge (bottom side) of the bottom portion 12 or the outer edge (top side) of the top portion 14 of the pouch 10 is referred to as the y direction, and the direction orthogonal to the y direction may also be referred to as the x direction (or width direction). In the pouch 10, the bottom portion 12 side may be referred to as the lower side, and the top portion 14 side may be referred to as the upper side.

[0020] An example of the length L1 of the pouch 10 in the x direction is 100 mm to 180 mm, and an example of the length L2 in the y direction is 100 mm to 200 mm. The pouch 10 has a pair of overlapping sheets 16, 18 (see FIGS. 3 and 4) and a sheet 20 (see FIG. 1).

[0021] The pair of sheets 16, 18 are the front sheet (or first side sheet) and the rear sheet (or second side sheet) of the pouch 10. The planar shape (shape viewed from the thickness direction) of the pair of sheets 16, 18 may be, for example, rectangular or square. Each of the sheets 16, 18 is a laminate (or laminated film) having a sealant layer on one surface. The pair of sheets 16, 18 are arranged so that the sealant layers face each other.

[0022] The sheet 20 is a sheet for forming the bottom portion 12 of the pouch 10. The sheet 20 is also a laminate (or laminated film) having a sealant layer on one surface.

[0023] Examples of the materials of the sheets 16, 18, 20 include polyethylene terephthalate (PET), nylon (NY), and olefin resins. The sheets 16, 18, 20 can be formed, for example, by laminating. In one embodiment, examples of the materials of the sealant layers of the sheets 16, 18, 20 are cast polypropylene (CPP) and linear low density polyethylene (LLDPE). In one embodiment, the sealant layer is formed of a heat-resistant material.

[0024] Sheets 16, 18, and 20 include, for example, the outermost layer, the middle layer, and the innermost layer. The outermost layer is the layer located opposite the innermost layer to the middle layer.

[0025] An example of a material constituting the outermost layer is a transparent material. Examples of transparent materials include PET and transparent vapor-deposited film. An example of a transparent vapor-deposited film is biaxially oriented polypropylene film (OPP: Oriented PolyPropylene). The intermediate layer includes, for example, a printed layer. The printed layer is located on the innermost layer side of the outermost layer. Pictures and product description text are printed on the outermost layer side of the printed layer. The intermediate layer may further include, for example, a first adhesive layer, an oriented nylon layer, and a second adhesive layer. The first adhesive layer is located on the innermost layer side of the printed layer. The oriented nylon layer is located on the innermost layer side of the first adhesive layer. The second adhesive layer is located on the innermost layer side of the oriented nylon layer. An example of a material constituting each adhesive layer is a dry laminate adhesive. The innermost layer is located on the opposite side of the intermediate layer from the outermost layer. The innermost layer is a sealant layer.

[0026] A pair of sheets 16 and 18 are stacked so that their sealant layers face each other. Sheet 20 is positioned on the bottom 12 side of the pouch 10 among the pair of sheets 16 and 18. Sheet 20 is folded into a self-supporting shape (e.g., gusseted) with the sealant layer facing outwards and is sandwiched between the stacked sheets 16 and 18. For example, sheet 20 is folded in half with the sealant layer facing outwards and inserted between the sheets 16 and 18.

[0027] The pouch 10 is heat-sealed around its perimeter. As a result, when the pouch 10 is closed, it has a bottom seal portion 22, a top seal portion 24, and a pair of side seal portions 26, 28. In Figures 1 and 2, the sealed areas are hatched to clearly indicate them. As will be described later, the top seal portion 24 is a seal portion formed after the contents 100 are placed in the open pouch 10.

[0028] The bottom seal portion 22 is the portion where the sheet 20, which is inserted between the pair of sheets 16 and 18 as described above, and the sheets 16 and 18 are heat-sealed. In Figures 1 and 2, the bottom seal portion 22 (or bottom portion 12) has a shape that is slightly curved from the center in the x-direction toward both sides, but the outer edge of the bottom seal portion 22 may be straight.

[0029] The top seal portion 24 is the part of the pair of sheets 16 and 18 where the edge on the side opposite to the bottom seal portion 22 (the top portion 14 side) is heat-sealed. The top seal portion 24 is formed when the contents 100 are placed in the open pouch 10, and then the top portion 14 side is heat-sealed.

[0030] The pair of side seal portions 26 and 28 are provided on both sides in the x-direction of the pair of overlapping sheets 16 and 18 to form a storage space S. The pair of side seal portions 26 and 28 connect the bottom seal portion 22 and the top seal portion 24.

[0031] One of the pair of side seal portions 26, 28, the side seal portion 26, is a seal portion located on one end side of the pouch 10 in the x direction. The side seal portion 26 is formed by heat sealing the pair of sheets 16, 18 along the outer edge of the sheet 16 (or sheet 18). An example of the seal width W1 (width in the direction perpendicular to the extending direction) of the side seal portion 26 is 3 mm to 15 mm.

[0032] Of the pair of side seal portions 26 and 28, the other side seal portion 28 is a seal portion located on the other end side of the pouch 10 in the x direction. The side seal portion 28 is configured to release steam generated when the pouch 10 is heated to the outside. Specifically, the side seal portion 28 has an upper seal portion (first seal portion) 30, a lower seal portion (second seal portion) 32, and a steam vent seal portion 34.

[0033] The upper seal portion 30 is the part of the side seal portion 28 located closer to the top portion 14. The upper seal portion 30 is formed by heat sealing a pair of sheets 16, 18 along the outer edge of sheet 16 (or sheet 18). An example of the seal width W2 of the upper seal portion 30 is the same as an example of the seal width W1 of the side seal portion 26. In this embodiment, the seal width W2 is the same as the seal width W1, but the seal width W2 may be different from the seal width W1.

[0034] The lower seal portion 32 is the portion of the side seal portion 28 that is located closer to the bottom 12 than the upper seal portion 30. The lower seal portion 32 is spaced apart from the upper seal portion 30 in the y-direction. Therefore, the region of the sheets 16, 18 between the lower seal portion 32 and the upper seal portion 30 along the y-direction is an unsealed region. The lower seal portion 32 is formed by heat sealing a pair of sheets 16, 18 along the outer edge of the sheet 16 (or sheet 18). An example of the seal width W3 of the lower seal portion 32 is the same as the example of the seal width W1 of the side seal portion 26. In this embodiment, the seal width W3 of the lower seal portion 32 is the same as the seal width W2 of the upper seal portion 30, but the seal width W3 may be different from the seal width W2. For example, the seal width W3 may be narrower than the seal width W2.

[0035] The steam vent seal portion 34 is a part provided to release steam generated when the pouch 10 is heated in the side seal portion 28 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 upper seal portion 30 and the lower seal portion 32. The steam vent seal portion 34 is also the part that protrudes toward the containment space S. Therefore, the side seal portion 28 has a shape that is recessed toward the containment space S in the part of the steam vent seal portion 34. The steam vent seal portion 34 is formed by heat sealing sheets 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 upper seal portion 30, the lower seal portion 32, and the side seal portion 26 so that steam can easily escape from the steam vent seal portion 34. For example, the seal width of the steam vent seal section 34 may be narrower than the seal width W2 of the upper seal section 30 and the seal width W3 of the lower seal section 32.

[0036] 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. The steam vent seal portion 34 has a tip portion 36, a first connection portion 38, and a second connection portion 40. In the example shown in Figure 5, the shape of the steam vent seal portion 34 is approximately V-shaped. In Figure 5 as well, the sealed area is indicated by hatching.

[0037] The tip portion 36 is located in a place where strong stress concentration occurs in the sheets 16 and 18 when the pressure in the containment space S increases due to the heating of the contents 100. The tip portion 36 is, for example, the part closest to the center C of the containment space S (see Figures 2 and 5). In one embodiment, the steam vent seal portion 34 may be formed such that the tip portion 36 faces the center C. The tip portion 36 is usually located closer to the top portion 14 than the center C in the y-direction.

[0038] Center C is the center of the containment space S when the pouch 10 is viewed from above (viewed from the x and y directions). In this embodiment, center C is the intersection of a line passing through the midpoint in the y direction of the edge of the side seal portion 26 on the containment space S side and parallel to the x direction, and a line passing through the midpoint in the x direction of the edge of the top seal portion 24 on the containment space S side and parallel to the y direction. Center C may also be, for example, the center of a sphere with the largest radius that fits into the containment space S in the closed pouch 10. Center C usually coincides with the center of the sheet 16 (or sheet 18).

[0039] The tip portion 36 is also the corner portion connecting the first connection portion 38 and the second connection portion 40. The tip portion 36 is located, for example, closer to the bottom seal portion 22 in the steam vent seal portion 34. The tip portion 36 may be curved toward the containment space S, as shown in Figure 5.

[0040] The first connecting portion 38 is the part that connects the tip portion 36 and the lower sealing portion 32. The first connecting portion 38 is the lower sealing portion of the steam vent sealing portion 34. The end of the first connecting portion 38 opposite to the tip portion 36 is continuously connected to the end portion 32a of the lower sealing portion 32. The first connecting portion 38 is oriented in the x direction. The sealing width W4 of the first connecting portion 38 is, for example, constant. An example of a sealing width W4 is 3 mm to 10 mm. In the example shown in Figure 5, the sealing width W4 is narrower than the sealing widths W2 and W3.

[0041] The connection between the first connecting portion 38 and the lower sealing portion 32 may be located closer to the bottom 12 than the end portion 32a of the lower sealing portion 32. The first connecting portion 38 may be inclined toward the bottom 12 toward the tip portion 36. That is, in the y-direction, the tip portion 36 may be located toward the bottom 12 than the connection point between the first connecting portion 38 and the lower sealing portion 32. The seal width W4 may vary in the x-direction. For example, the seal width W4 may narrow toward the tip portion 36.

[0042] The second connecting portion 40 is the part that connects the tip portion 36 and the upper sealing portion 30. In the example shown in Figure 5, the second connecting portion 40 extends from the tip portion 36 toward the upper sealing portion 30 and is inclined with respect to the y direction. The end of the second connecting portion 40 opposite to the tip portion 36 is continuously connected to the end portion 30a of the upper sealing portion 30.

[0043] The second connecting portion 40 has a first portion 42 and a second portion 44, which have different inclination angles with respect to the y-direction.

[0044] The first part 42 is the portion of the second connecting part 40 that is on the tip end 36 side. An example of the seal width W5 of the first part 42 is 3 mm to 10 mm. In the example shown in Figure 5, the seal width W5 is narrower than the seal widths W2 and W3. The seal width W5 may vary so that it widens on the second part 44 side of the tip end 36. However, the seal width W5 may be the same as the seal widths W2 and W3. The seal width W5 may also be constant.

[0045] The second portion 44 is the part of the second connecting portion 40 between the first portion 42 and the upper seal portion 30. The second portion 44 is inclined at a larger angle than the inclination angle of the first portion 42 with respect to the y-direction. Therefore, the second connecting portion 40 is bent at the connection point between the first portion 42 and the second portion 44. Typically, the connection point (bent portion) between the first portion 42 and the second portion 44 is located closer to the upper seal portion 30 in the second connecting portion 40. An example of the seal width W6 of the second portion 44 is 3 mm to 15 mm. In the example shown in Figure 5, the seal width W6 is wider than the seal width W5 of the first portion 42, but they may be the same.

[0046] The first region 46a between the upper seal portion 30 and the lower seal portion 32 in the y direction, and the second region 46b surrounded by the steam vent seal portion 34 (more specifically, the region surrounded by the first region 46a and the steam vent seal portion 34) are unsealed regions 46 in which the pair of sheets 16 and 18 are not sealed. That is, in the pair of sheets 16 and 18, the side opposite to the side seal portion 26 in the x direction is sealed in such a way that an unsealed region 46 is formed.

[0047] As shown in Figures 4 and 5, the unsealed region 46 has through-ports 48 that penetrate through the sheets 16 and 18 in the thickness direction (directions perpendicular to the x and y directions). The through-ports 48 are, for example, notches, cutouts, or slits. In one embodiment, a portion of the through-port 48 is located on the side of the accommodating space S side of a virtual line (first virtual line) 50a, which is an extension of the edge of the upper sealing portion 30 or the lower sealing portion 32 that is closest to the accommodating space S side, as shown in Figure 5. The through-port 48 is located on a virtual line 50b (second virtual line) that virtually connects the center C and the tip portion 36, as shown in Figure 2. For example, the portion of the through-port 48 closest to the center C may be located on the virtual line 50b.

[0048] The plan view shape of the through-port 48 is, for example, an arc (e.g., a circular arc, a crescent shape, etc.) that curves inward towards the inside of the pouch 10 (e.g., towards the center C of the storage space S). As described above, in one embodiment, the portion of the through-port 48 that is closest to the center C of the storage space S is located on the imaginary line 50b. When the arc-shaped through-port 48 is viewed from above, an example of the length L3 between the first end 48a and the second end 48b (the end opposite to the first end 48a) of the through-port 48 is 5 mm to 15 mm, and is preferably 7.5 mm or more.

[0049] The through portion 48 can be formed, for example, by making cuts (or slits) in the sheets 16 and 18 with a blade having the shape of the through portion 48, or by cutting out the sheets 16 and 18.

[0050] In one embodiment, the pair of side seal portions 26, 28 may have at least one pair of notches n formed thereon, as shown in Figures 1 and 2. The at least one pair of notches n is a notch for opening the pouch 10 after heating the contents 100. Figures 1 and 2 show an example where the pouch 10 has two pairs of notches n1, n2. The two pairs of notches n1, n2 will be described with reference to Figure 2.

[0051] The pair of notches n1 are formed near the top seal portion 24. In the example shown in Figure 2, the pair of notches n1 are formed such that one of them is located at the top seal portion 30. The pair of notches n1 are notches that allow the end user to open the pouch 10 in order to remove the heated contents 100 from the pouch 10 into another container (such as a plate). The pair of notches n1 should be formed such that the pouch 10 is opened when the pouch 10 is broken from one notch n1 to the other.

[0052] The pair of notches n2 are formed between the area of ​​the pouch 10's storage space S where the contents 100 are contained and the pair of notches n1. In the example shown in Figure 2, the pair of notches n2 are formed such that one of them is located at the bottom seal portion 32. The pair of notches n2 are notches that allow the end user to use the part of the pouch 10 closer to the bottom seal portion 22 than one of the notches n2 as a container for the contents 100 when the pouch 10 is broken from one of the second notches toward the other. As in the example shown in Figure 2, raised portions (or tabs) may be provided on both sides in the y direction of the notch n2 located on the side seal portion 26 side of the pair of notches n2. This makes it easier to break the pouch 10 from the notch n2 on the side seal portion 26 side toward the other notch n2. Such raised portions may be provided on one of the pair of notches n1, for example.

[0053] The above pouch 10 can be manufactured, for example, as follows:

[0054] A pair of sheets 16 and 18 are overlapped so that their sealant layers face each other. A sheet 20, folded to a self-supporting shape with the sealant layer facing outwards, is sandwiched between the overlapping pair of sheets 16 and 18, as described above. In this state, the sheets 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 48 is formed in the unsealed area 46 on the side of the side seal portion 28. This results in an open pouch 10.

[0055] 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.

[0056] The process of forming the through portion 48 is not limited to after the bottom seal portion 22 and the pair of side seal portions 26, 28 have been formed as described above. The through portion 48 can be formed at any stage before the contents 100 are placed in the storage space S. For example, sheets 16, 18 with the through portion 48 already formed may be prepared.

[0057] If the pouch 10 has at least one pair of notches n, for example, the pouch 10 may be manufactured by preparing sheets 16, 18 with at least one pair of notches n already formed on them, or the at least one pair of notches n may be formed at any stage before the contents 100 are placed in the storage space S.

[0058] Next, we will explain the effects of pouch 10. First, we will explain the case where pouch 10 is heated using, for example, the output of a household microwave oven (for example, around 600W).

[0059] In this case, steam is generated when the contents 100 are heated, increasing the pressure inside the containment space S. The pouch 10 has a steam vent seal portion 34. The steam vent seal portion 34 protrudes towards the containment space S. Furthermore, since the tip portion 36 of the steam vent seal portion 34 is close to the center C of the containment space S, strong stress concentration occurs when the pressure inside the containment space S rises. Therefore, peeling of the steam vent seal portion 34 usually begins from the tip portion 36 and progresses along the shape of the steam vent seal portion 34. This peeling creates an opening in the steam vent seal portion 34, connecting the containment space S and the unsealed area 46. As a result, the unsealed area 46 functions as a steam vent for releasing steam, and the steam inside the containment space S escapes to the outside of the pouch 10 through the unsealed area 46.

[0060] Next, the case of heating the pouch 10 under high power (for example, microwaves of 1000W or more) will be explained in comparison to the case where a through-hole 48 is not formed in the unsealed region 46. For the sake of explanation, even in the explanation of the case where a through-hole 48 is not formed, the elements corresponding to the components of the pouch 10 described so far will be given the same reference numerals. Heating the pouch 10 under high power corresponds, for example, to heating in a commercial microwave oven in a convenience store.

[0061] When heating pouch 10 with a high-power microwave (for example, 1000W or more), the contents 100 are more likely to be heated rapidly compared to heating the contents 100 with the output of a household microwave oven (600W, etc.). As a result, steam is generated rapidly, and the rate at which the internal pressure of the containment space S rises also increases. In this case, if there is no through-hole 48 in the unsealed area 46, the delamination of the steam vent seal 34 progresses rapidly, and the area near the center C expands rapidly, causing the unsealed area 46 (especially the outer edges of the sheets 16, 18 in the unsealed area 46) to become blocked, as discovered by the inventors. When the unsealed area 46 becomes blocked in this way, there is a risk that the pouch 10 may rupture because steam cannot escape, or that other seals may peel off, causing the contents 100 to spill out of the pouch 10.

[0062] In contrast, the pouch 10 according to this embodiment has a through-hole 48 in the unsealed area 46. In this case, even if the internal pressure of the pouch 10 heated at high power increases rapidly, the through-hole 48 functions as a steam vent for releasing steam, thus eliminating the aforementioned problems that occur when the pouch does not have a through-hole 48, and allowing the pouch 10 (specifically, the contents inside the pouch 10) to be heated safely even at high power.

[0063] If at least a portion of the penetration portion 48 is located on the side of the accommodation space S relative to the imaginary line 50a, deformation such as bending of the upper seal portion 30, the lower seal portion 32, etc. can be prevented. Furthermore, if at least a portion of the penetration 48 is located on the side of the containment space S relative to the virtual line 50a, the portion of the penetration 48 located on the side of the containment space S relative to the virtual line 50a is more likely to function as at least the aforementioned steam vent under high power, thus enabling safer heating of the pouch 10 even under high power. Furthermore, steam is more reliably released. If at least a portion of the penetration 48 is located on the side of the containment space S relative to the imaginary line 50a, steam can be more easily released from the penetration 48 before delamination occurs in the seal portions other than the steam venting seal portion 34 (for example, the upper seal portion 30, the lower seal portion 32, etc.).

[0064] When steam is generated, it tends to propagate outward from the center C. Therefore, if the penetration 48 is located on the virtual line 50b, steam is more easily released from the penetration 48. If the part of the penetration 48 closest to the center C is located on the virtual line 50b, steam is even more easily released from the penetration 48.

[0065] If the penetration portion 48 is curved in an arc towards the containment space S, steps are formed on both sides of the penetration portion 48 (for example, on both sides in the x-direction or along the imaginary line 50b), making it easier for larger openings to be formed in sheets 16 and 18. For example, when the pressure inside the containment space S increases rapidly, the center C side of the containment space S expands, while the area near sheets 16 and 18 in the unsealed region 46 closes as described above. As a result, the aforementioned steps are created, making it easier for larger openings to be formed. Consequently, steam can escape more easily, allowing the pouch 10 to be heated more safely under high power.

[0066] Next, I will explain an example experiment.

[0067] In the experimental example, pouch 10A, shown in Figure 6, was used as the basic configuration, and multiple experiments were conducted by changing the size and position of the penetration 48. The basic configuration of pouch 10A is the same as that of pouch 10 shown in Figures 1 and 2. Pouch 10A shown in Figure 6 is the pouch in an open state. Pouch 10A will be described by assigning the same reference numerals to elements corresponding to the components of pouch 10. In the description of pouch 10A, explanations that overlap with the description of pouch 10 will be omitted as appropriate.

[0068] The layer configuration of sheets 16, 18, and 20 in pouch 10A was as follows: Transparent vapor-deposited PET film / PET film / Heat-resistant CPP film The thickness of the transparent vapor-deposited PET film was 12 μm. The thickness of the PET film was 12 μm. The thickness of the heat-resistant CPP film was 60 μm. In the above layer configuration, the heat-resistant CPP was the sealant layer.

[0069] The side seal portion 26 was a seal portion having a constant seal width W1. The side seal portion 28 was a seal portion having an upper seal portion 30, a lower seal portion 32, and a steam vent seal portion 34. The seal width W2 of the upper seal portion 30 was constant. The seal width W3 of the lower seal portion 32 was constant.

[0070] At the first connecting portion 38 of the steam vent seal portion 34, the end opposite to the tip portion 36 was continuously connected to the end portion 32a of the lower seal portion 32. At the second connecting portion 40 of the steam vent seal portion 34, the end opposite to the tip portion 36 was continuously connected to the end portion 34a of the upper seal portion 30. The second connecting portion 40 had a first portion 42 and a second portion 44.

[0071] Penetrations 48 were formed in the sheets 16 and 18 in the unsealed region 46. The penetrations 48 were in the shape of an arc that curved toward the center C of the containment space S.

[0072] Pouch 10A was manufactured as follows: A pair of sheets 16 and 18 having the layered structure described above were stacked, and then a sheet 20, folded in half with the heat-resistant CPP film facing outwards, was inserted between them. The sheets 16, 18, and 20 were then heat-sealed to form a bottom seal portion 22 and a pair of side seal portions 26 and 28. Next, a through portion 48 was formed in the unsealed area 46 formed by the side seal portion 28. The through portion 48 was formed by pressing a blade having the shape of the through portion 48 into the sheets 16 and 18.

[0073] The dimensions of pouch 10A are explained with reference to Figures 6 and 7. The dimensions of pouch 10A were as follows: The length L1 in the x-direction of pouch 10A (see Figure 6) was 150 mm. The length L2 in the y-direction of pouch 10A was 158 mm. When the open pouch 10A was viewed from above, the length L4 of the folded sheet 20 was 45 mm. The seal width W1 of the side seal section 26, the seal width W2 of the upper seal section 30, and the seal width W3 of the lower seal section 32 were all 8 mm. The length L5 (see Figure 7) from the outer edge of the top part 14 to the lower edge of the first connecting part 38 was 58 mm. The length L6 from the outer edge of the top section 14 to the first intersection of the second connecting section 40 and the upper seal section 30 (the intersection on the top section 14 side) was 33.65 mm. In the y-direction, the length L7 from the first intersection to the second intersection of the first part 42 and the second part 44 (the intersection on the top part 14 side) was 0.65 mm. In the x-direction, the length L8 from the edge of the upper seal portion 30 on the side of the accommodating space S to the second intersection was 3.37 mm. In the x-direction, the length L9 from the outer edge of sheet 16 (or sheet 18) to the third intersection of the first part 42 and the second part 44 (the intersection on the bottom 12 side) was 10.18 mm. In the x-direction, the length L10 between the point of the tip portion 36 furthest from the edge of the lower seal portion 32 on the side of the housing space S and the edge of the lower seal portion 32 on the side of the housing space S was 10 mm. In the x-direction, the length L11 from the edge of the lower seal portion 32 on the side of the accommodating space S to the connection point between the edge of the first connection portion 38 on the side of the unsealed area 46 and the edge of the second connection portion 40 on the side of the unsealed area 46 was 7 mm. The seal width W4 of the first connection part 38 was 3 mm. The seal width W6 of the second portion 44 of the second connection part 40 was 7.5 mm. The tip portion 36 was curved, and the radius of curvature of the edge of the tip portion 36 on the side of the housing space S was 4.5 mm. In the x-direction, the length L12 between the first end 48a and the second end 48b of the through-port 48 was 5.3 mm. In the y-direction, the length L13 between the first end 48a and the second end 48b was 5.3 mm. In the y-direction, the length L14 between the second end 48b and the upper end of the lower seal portion 32 was 2.5 mm. In the x-direction, the length L15 between the second end 48b and sheet 16 (or sheet 18) was 4.58 mm. • The radius of curvature of the part of the penetration 48 closest to the center C of the accommodating space S was 4 mm. The length L3 between the first end 48a and the second end 48b of the through-hole 48 was 7.5 mm.

[0074] The first end 48a of the through-hole 48, created with the above dimensions, was located on the side of the housing space S beyond the imaginary line 50a (see Figure 5), which is an extension of the edges of the upper seal portion 30 and the lower seal portion 32 on the housing space S side. Furthermore, the through-hole 48 was located on the imaginary line 50b (see Figure 5).

[0075] (Experimental Example 1) In Experimental Example 1, 180g of water was placed in the storage space S of the basic pouch 10A, and then the top portion 14 was closed to form a top seal portion 24. The sealed pouch 10A containing 180g of water was heated in a microwave oven. The power output during heating was 1600W, and the heating time was 30 seconds. The presence or absence of closure of the unsealed area 46 during this microwave cooking was checked.

[0076] The above experiment was performed using five pouches 10A with the same configuration. In all five pouches 10A, if no occlusion occurred in the unsealed area 46, it was rated "A," and otherwise it was rated "B." The result for Experiment Example 1 was rated A.

[0077] (Experimental Example 2) In Experiment Example 2, as shown in Table 1, in addition to Experiment 2-1 using the pouch 10A with the basic configuration described above, Experiments 2-2, 2-3, and 2-4 were conducted by changing the length and position of the penetration portion 48 in the pouch 10A with the basic configuration. [Table 1]

[0078] In Table 1, the "reference position" was the position of the through-hole 48 as described in the basic configuration pouch 10A. A position of "+3mm" for the through-hole 48 means that, as shown in Figure 8, the through-hole 48 was formed by moving it 3mm outward (opposite to the center C) along the imaginary line 50b from the reference position of the through-hole 48 (the position of the through-hole 48 shown by the solid line). Conversely, a position of "-3mm" for the through-hole means that, as shown in Figure 8, the through-hole 48 was formed by moving it 3mm inward (towards the center C) along the imaginary line 50b from the reference position of the through-hole 48. In both cases, whether the position of the through-hole 48 was "+3mm" or "-3mm", the first end 48a of the through-hole 48 was located on the side of the housing space S than the imaginary line 50a (see Figure 5), which is an extension of the edge of the upper seal portion 30 and the lower seal portion 32 on the housing space S side.

[0079] Experiments 2-1 to Experimental Example 2-4 were conducted in the same manner as Experimental Example 1, except that 180g of curry was used instead of 180g of water. In Experiments 2-1 to Experimental Example 2-4, in addition to evaluating the blockage state of the unsealed area 46 as in Experimental Example 1, the peeling state of the seals other than the steam vent seal 34 during microwave cooking was also evaluated. In this evaluation of the peeling state of the seals, in all experiments using the five pouches in Experiments 2-1 to Experimental Example 2-4, a "Grade A" was given if no peeling occurred in the seals other than the steam vent seal 34, and a "Grade B" was given otherwise. The method for evaluating the blockage state of the unsealed area 46 in Experiments 2-1 to Experimental Example 2-4 was the same as in Experimental Example 1.

[0080] In Experimental Example 2, as a comparative experiment, Experiment 2-5 was conducted using pouch 10A in the state before the penetration portion 48 was formed. The experimental method and evaluation method for Experimental Example 2-5 were the same as those for Experimental Examples 2-1 to 2-4.

[0081] The experimental results for Experiments 2-1 to 2-5 are shown in Table 2. In Table 2, "Delamination State Evaluation" evaluates the delamination state of the seal parts other than the steam vent seal part 34. In Table 2, "Blockage State Evaluation" evaluates the blockage state of the unsealed area 46. [Table 2]

[0082] As shown in the results of Experiment 2-5, when a pouch 10A without a through-hole 48 was heated at a high power of 1600W, blockage of the unsealed region 46 occurred. On the other hand, in experiments using a pouch 10A with a through-hole 48, blockage of the unsealed region 46 did not occur. As a result, it was verified that by using a pouch with a through-hole 48 in the unsealed region 46, the pouch can be safely heated even at high power.

[0083] The layer configuration of sheets 16, 18, and 20 is not limited to the specific layer configurations shown in the experimental examples above, as long as it has a layer configuration that can be used as a pouch. For example, other examples of the layer configuration of sheets 16, 18, and 20 may include the following configurations. Transparent vapor-deposited PET film / NY film / Heat-resistant CPP film

[0084] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above. The present invention is intended to include all modifications within the scope set forth in the claims and within the meaning and scope equivalent to the claims.

[0085] The shape and size of the penetration are not limited as long as the penetration functions as an opening for releasing steam during heating of the pouch under high power. The shape and size of the penetration may be appropriately designed according to the size of the steam venting seal and the unsealed area, without departing from the spirit of the present invention.

[0086] For example, the through-hole may be a straight through-hole 52 as shown in Figure 9(a). The through-hole 52 may be formed such that, for example, the first end 52a of the through-hole 52 is located on the upper seal portion 30 side in the y direction, and the second end 52b (the end opposite to the first end 52a) is located on the lower seal portion 32 side. In this case, the through-hole 52 may be formed such that the first end 52a is further from the edge of the upper seal portion 30 (or lower seal portion 32) in the x direction than the second end 52b.

[0087] The through-section may be a U-shaped through-section 54 as shown in Figure 9(b). The through-section 54 has a first portion 54a and a second portion 54b and a third portion 54c, each having one end connected to both ends of the first portion 54a. In this case, the through-section 54 may be formed such that the first portion 54a faces the tip portion 36. At least one of the first portion 54a, the second portion 54b, and the third portion 54c may be curved.

[0088] The through-hole may be a V-shaped through-hole 56 as shown in Figure 9(c). The through-hole 56 has a first side 56a and a second side 56b, and the first side 56a and the second side 56b are connected at a substantially acute angle. In this case, the through-hole 56 can be formed such that the corner (or apex) formed by the first side 56a and the second side 56b faces the tip 36.

[0089] Furthermore, the shape of the through-hole may be S-shaped. The through-hole may also be the opening of the pouch before heating. Multiple through-holes may be formed in the unsealed region 46. If multiple through-holes are formed in the unsealed region 46, the multiple through-holes may be the same shape or may be different shapes.

[0090] The shape of the steam vent seal portion 34 is not limited to the approximately V-shape illustrated. For example, a U-shaped steam vent seal portion is also acceptable. Similarly, the shape of the unsealed region 46 is not limited to the trapezoidal shape shown in Figure 5.

[0091] The steam vent seal portion may also be formed in the side seal portion 26 illustrated in Figures 1 and 2. In this case, a through portion may be formed in the unsealed area 46 provided on the side seal portion 26. The through portion does not have to be formed in either sheet 16 or sheet 18.

[0092] The sealing method for sheets 16, 18, etc. is not limited to heat sealing, as long as the sheets can be sealed. For example, sheets 16, 18, etc. may be sealed by ultrasonic sealing, high-frequency sealing, etc. The layer structure and materials of sheets 16, 18, etc. can be appropriately changed depending on the sealing method.

[0093] The pouch does not necessarily have to have a sheet 20. In this case, for example, the edges of a pair of overlapping sheets can be sealed and the bottom seal folded in to create a self-standing pouch.

[0094] The embodiments and various modifications described above may be combined as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0095] 10...pouch, 12...bottom, 14...top, 16,18...pair of sheets, 26,28...pair of side seals, 30...top seal, 32...bottom seal, 34...steam vent seal, 36...tip, C...center, 46...unsealed area, 46a...first area, 46b...second area, 48...penetration, 50a...virtual line (first virtual line), 50b...virtual line (second virtual line), 52,54,56...penetration, 100...contents, S...container space.

Claims

1. A pouch having a storage space for containing contents between the bottom and the top opposite the bottom, A pair of overlapping sheets, A pair of side seal portions are provided on both sides of the pair of sheets, and the pair of sheets are sealed to form the storage 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, A steam vent seal portion connects the first seal portion and the second seal portion and protrudes toward the containment space to release steam, It has, The area formed by the first region between the first seal portion and the second seal portion, and the second region surrounded by the first region and the steam vent seal portion, is an unsealed region. In the unsealed region of at least one of the pair of sheets, a through portion is formed that penetrates the at least one sheet in the thickness direction. The steam venting seal portion has a tip portion located closest to the center of the containment space within the steam venting seal portion, One of the first and second ends of the through portion is located on the side of the housing space that is virtually extended from the first imaginary line, which is the edge of the first and second sealing portions that is closest to the housing space, and the other end is located on the side of the housing space that is opposite to the first imaginary line. The aforementioned penetrating portion is located on a second imaginary line connecting the center of the housing space and the tip portion. The portion of the penetration closest to the center of the accommodation space is located on the second imaginary line, Pouch.

2. The through-hole is formed in both of the pair of sheets. The pouch according to claim 1.

3. The shape of the through portion as viewed from the thickness direction is an arc that curves toward the center of the storage space. The pouch according to claim 1 or 2.

4. The aforementioned through portion is V-shaped or S-shaped. The pouch according to claim 1 or 2.

5. The aforementioned through portion is V-shaped, The through portion has a first side and a second side that together with the first side forms the apex of the V shape. The through portion is formed such that the top portion faces the tip portion. The pouch according to claim 4.

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