JP6955199B2 - Steamable flat pouch - Google Patents

Description

The present invention relates to a steamable flat pouch.

A steaming type flat pouch that discharges water vapor generated from the contents by heating to the outside is known. Patent Document 1 discloses an example of a conventional steamable flat pouch. As shown in FIG. 11, the steamable flat pouch (100) of Patent Document 1 closes the laminate (150) forming the accommodation space (110) in which the contents are accommodated and the accommodation space (110). It is provided with a heat-welded portion (120) to which the laminated body (150) is joined as described above. The heat-welded portion (120) is formed so as to project from the outer peripheral portion (121) corresponding to the outer shape of the steam-permeable flat pouch (100) toward the accommodation space (110). It is divided into an overhanging part (130). In the portion surrounded by the outer peripheral portion (121) and the overhanging portion (130), the outside of the steaming type flat pouch (100) is formed in a state where the accommodation space (110) is closed by the heat welding portion (120). A communicating notch (140) is formed. In the state where the overhanging portion (130) joins the laminated body (150), the accommodation space (110) and the notch (140) are closed by the overhanging portion (130), so that the accommodation space (110) The contents of do not move to the notch (140).

When the steaming type flat pouch (100) is heated by a heating means such as a microwave oven, the pressure in the accommodation space (110) rises due to the steam generated from the contents, so that the overhanging portion (130) is peeled off. The acting force is applied to the overhanging portion (130). When the pressure in the accommodation space (110) rises to a certain pressure, a part of the overhanging portion (130) is peeled off as shown in FIG. 12, and the peeling off of the overhanging portion (130) is the heat welding portion (130). Proceed toward the outer peripheral portion (121) of 120). As shown in FIG. 13, when the peeling of the overhanging portion (130) reaches the notch (140), the accommodation space (110) and the outside of the steaming type flat pouch (100) are formed through the notch (140). The water vapor in the accommodation space (110) is discharged to the outside through the notch (140).

Japanese Unexamined Patent Publication No. 11-20739

According to the steaming type flat pouch (100), among the laminated body (150) in a state where the accommodation space (110) and the outside of the steaming type flat pouch (100) communicate with each other through the notch (140). In the heat-welded portion (120) which is a part of the portion where the notch (140) is formed, the upper laminated body (151) and the lower laminated body (152) are connected. Therefore, the distance between the notch (140) and the contents is short, and when water vapor is discharged from the notch (140), the contents may leak from the notch (140) together with the water vapor.

(1) The steam-permeable flat pouch according to the present invention has a seal portion that seals the sheets stacked so as to form an accommodation space for accommodating the contents, and a portion of the sheet inside the seal portion. In the inner portion, which joins a part of the sheet so as to be connected to the seal portion, the accommodating space and the outside are not communicated with each other in a state where the steam seal portion is not peeled off. In addition, a steam discharge portion formed in the heat-permeable seal portion so as to communicate the accommodation space with the outside in a state where the ventilation seal portion is peeled off is provided, and the heat-permeable seal portion is provided with a pressure in the accommodation space. The peeling of the steam sealing portion includes a preceding peeling portion including a portion to be peeled first in the steam sealing portion and a trailing peeling portion including a portion to be peeled last in the steam sealing portion. The width of the trailing peeling portion with respect to the traveling direction of is narrower than the width of the preceding peeling portion with respect to the traveling direction of the peeling.
When a steaming flat pouch whose accommodation space is closed by a seal is heated by a heating means, in one example, one of the stacked sheets is located below, the other of the superposed sheets, and steam. The sheet on which the discharge portion is formed is set so as to be located above. When the steaming type flat pouch is heated in that state, the pressure in the accommodation space rises due to the water vapor generated from the contents, and the force acting to peel off the steaming seal portion is applied to the steaming seal portion. When the pressure in the accommodating space rises to a certain pressure, the steam-permeable seal portion starts peeling from the preceding peeled portion, and the peeling of the steam-permeable seal portion proceeds toward the trailing peeled portion. When the peeling of the steaming seal portion reaches the steam discharge portion, the steam discharge portion communicates the accommodation space with the outside, so that the steam in the accommodation space is discharged to the outside through the steam discharge portion. Therefore, the increase in the pressure in the accommodating space is suppressed, and the force acting to peel off the steam-permeable seal portion is reduced. However, since the width of the trailing peeling portion is narrower than the width of the leading peeling portion, it is unlikely that the peeling of the steam sealing portion stops before the end of the trailing peeling portion. When the peeling of the steam sealing part reaches the end of the trailing peeling part, the part of the upper sheet that was joined by the steam sealing part is moved upward so as to be separated from the lower sheet and the contents. Moving. In the above-mentioned steaming type flat pouch, the steaming seal portion is formed in the inner portion, and the steam discharging portion is formed in the steaming sealing portion. Therefore, the steam is discharged as the upper sheet moves upward. The portion also moves upward so as to move away from the lower sheet and contents. Therefore, the contents are less likely to leak when the water vapor is discharged.

(2) In a preferred example, in the steaming type flat pouch according to (1), the trailing peeling portion is formed so as to become narrower toward the traveling direction side of the peeling.
Therefore, when a force acting to peel off the steam-permeable seal portion is applied to the steam-permeable seal portion, local stress concentration is unlikely to occur in the steam-permeable seal portion.

(3) In a preferred example, in the steaming type flat pouch according to (1) or (2), the steam discharge portion includes a notch or a hole penetrating one of the stacked sheets, and the direction of progress of the peeling. It is formed so as to extend to.
When the peeling of the steaming seal does not reach the hole or notch in the steam discharge part, the hole or notch does not communicate the accommodation space with the outside. When the peeling of the steam seal part reaches the hole or notch, the hole or notch communicates with the accommodation space and the outside, and as the peeling progresses, the area of the part that directly communicates with the accommodation space in the hole or notch (hereinafter referred to as "Communication area") expands. Since the steaming type flat pouch is formed so that the holes or cuts extend in the direction of progress of peeling, the communication area gradually increases as the peeling progresses. Therefore, the sudden increase in the flow rate of water vapor discharged from the accommodation space to the outside is suppressed, and the peeling of the steaming seal portion easily reaches the end of the trailing peeling portion.

(4) In a preferred example, in the steamable flat pouch according to any one of (1) to (3), the sheet and the seal portion are used to open the accommodation space closed by the seal portion. A guide portion that constitutes a guide for separating a part is further provided, and the steam sealing portion is provided in a portion of the sheet that is separated by the guide portion.
For this reason, when the part of the sheet that is separated by the guide part (hereinafter referred to as the "separation part") is separated, the steam discharge part does not remain in the part of the sheet that houses the contents, and the contents are removed. The contents do not leak from the steam outlet when taken out of the containment space.

(5) In a preferred example, in the steaming type flat pouch according to any one of (1) to (4), the dimension of the steam discharge portion in the peeling progress direction is the steaming in the peeling progress direction. It is 12.5% or more of the size of the seal portion.
When the dimensions of the steam discharge section are included in the above range, steam is appropriately discharged from the steam discharge section when the accommodation space and the outside communicate with each other via the steam discharge section.

(6) In a preferred example, in the steaming type flat pouch according to any one of (1) to (5), the dimension of the steam discharge portion in the peeling progress direction is the steaming in the peeling progress direction. It is 62.5% or less of the size of the seal portion.
When the dimensions of the steam discharge section are included in the above range, it is difficult for foreign matter to enter the steam discharge section.

(7) In a preferred example, the steaming type flat pouch according to any one of (1) to (6) further includes the contents housed in the storage space.

According to the steaming type flat pouch according to the present invention, the contents are less likely to leak when steam is discharged.

Front view of the steaming type flat pouch of the embodiment. An enlarged view of the steam sealing portion of FIG. 1 and its surroundings. Front view of a steamable flat pouch before the opening is closed. The front view of the steaming type flat pouch in the state where a part of the steaming seal part of FIG. 1 is peeled off. The front view of the steaming type flat pouch in the state where the whole of the steaming seal part of FIG. 4 is peeled off. FIG. 5 is a cross-sectional view taken along the line D6-D6 of FIG. A table showing the test conditions of comparative examples and examples related to the test. A table showing the test results of Comparative Examples and Examples. Enlarged view of the steam seal part of the modified example and its surroundings. Enlarged view of the steam seal part of the modified example and its surroundings. Front view of a conventional steamable flat pouch. FIG. 11 is a cross-sectional view taken along the line D12-D12 of FIG. FIG. 2 is a cross-sectional view of the overhanging portion of FIG. 12 in a peeled state.

(Embodiment)
FIG. 1 shows an example of a steaming type flat pouch 10 capable of accommodating a content C suitable for heating and discharging water vapor generated from the content C. The content C generates water vapor when heated. An example of content C is food. An example of food is food that is cooked. Examples are beef bowl steak, hamburger steak, and stew. The steamable flat pouch 10 is configured to be able to be stored for a long period of time while maintaining the quality of the content C.

The steaming type flat pouch 10 includes a sheet 20, a sealing portion 30, an opening 40 (see FIG. 3), a guide portion 50, a steaming sealing portion 60, and a steam discharging portion 70. The dots in FIG. 1 and the like represent the sealing portion 30 and the steam sealing portion 60. The sheet 20 includes a first sheet 21 and a second sheet 22. The first sheet 21 and the second sheet 22 face each other so that a storage space 10C for accommodating the content C is formed between the sheets 21 and 22. The configuration of the sheet 20 can be arbitrarily selected. In the first example, each of the sheets 21 and 22 is two individually formed sheets. In the second example, one sheet is bent to form the opposing sheets 21 and 22.

The sheet 20 has a layered structure in which a plurality of layers are laminated. The layer structure of the sheet 20 can be arbitrarily selected. In the first example, the sheets 21 and 22 have the same layer structure. In the second example, the first sheet 21 and the second sheet 22 have different layer structures. FIG. 1 shows a steamable flat pouch 10 composed of a sheet 20 having a layered structure of the first example.

Each sheet 21, 22 includes an outermost layer, an intermediate layer, and an innermost layer. An example of the manufacturing method of each of the sheets 21 and 22 is dry lamination. The outermost layer is mainly excellent in gloss, printability, and retort resistance. An example of the material constituting the outermost layer is a transparent material. An example of a transparent material is polyethylene terephthalate. The intermediate layer is mainly excellent in retort resistance, moisture resistance, and gas blocking property. The intermediate layer includes a printing layer, a first adhesive layer, a stretched nylon layer, and a second adhesive layer. The print layer is provided inside the outermost layer. In one example, a pattern, a text of a product description, or the like is printed on the outer surface of the print layer. The first adhesive layer is provided inside the print layer. The stretched nylon layer is provided inside the first adhesive layer. The second adhesive layer is provided inside the stretched nylon layer. An example of the material constituting each adhesive layer is a dry laminate adhesive. The innermost layer has excellent retort resistance, heat sealability, and impact resistance. The innermost layer is provided inside the second adhesive layer. An example of the material constituting the innermost layer is unstretched polypropylene.

The seal portion 30 joins the sheets 21 and 22 so that the sheets 21 and 22 do not separate from each other. In one example, the seal portion 30 joins the innermost layer of the first sheet 21 and the innermost layer of the second sheet 22. An example of a method for forming the seal portion 30 is a heat seal. The outer shape of the steam-permeable flat pouch 10 in front view can be arbitrarily selected. In the example shown in FIG. 1, the outer shape of the steamable flat pouch 10 is rectangular. The sheet 20 can be divided into a portion surrounded by the seal portion 30 (hereinafter, “inner portion 23”) and a seal portion 30. The accommodation space 10C is a space surrounded by the inner portion 23 of the first sheet 21 and the inner portion 23 of the second sheet 22, and is closed by the seal portion 30 so as not to communicate with the outside of the steaming type flat pouch 10. Has been done.

The seal portion 30 joins the first sheet 21 and the second sheet 22 so that the accommodation space 10C is closed. The seal portion 30 is divided into a first seal portion 31 to a fourth seal portion 34. The first seal portion 31 is formed along the first side 20A of the sheet 20. The second seal portion 32 is formed along the second side 20B of the sheet 20. The third seal portion 33 is formed along the third side 20C of the sheet 20. The fourth seal portion 34 is formed along the fourth side 20D of the sheet 20. The first seal portion 31, the third seal portion 33, and the fourth seal portion 34 are formed before the second seal portion 32 in order to accommodate the contents in the accommodation space 10C. When the first seal portion 31, the third seal portion 33, and the fourth seal portion 34 are formed and the second seal portion 32 is not formed, the opening 40 for putting the contents into the accommodation space 10C is formed. (See FIG. 3) is formed in the steaming type flat pouch 10. The second seal portion 32 is formed after the contents are put into the accommodation space 10C, and the opening 40 is closed by the second seal portion 32. Hereinafter, the direction along the first side 20A and the second side 20B is referred to as the first direction, and the direction along the third side 20C and the fourth side 20D is referred to as the second direction in the front view of the steaming type flat pouch 10. ..

At the inner edge 31A, which is the edge on the inner portion 23 side of the first seal portion 31, the inner edge 32A, which is the edge on the inner portion 23 side of the second seal portion 32, and the edge on the inner portion 23 side of the third seal portion 33. A certain inner edge 33A and an inner edge 34A, which is an edge on the inner side 23 side of the fourth seal portion 34, define the outer shell of the inner portion 23. The outer edge 31B, which is the edge opposite to the inner edge 31A of the first seal portion 31, the outer edge 32B, which is the edge opposite to the inner edge 32A of the second seal portion 32, and the side opposite to the inner edge 33A of the third seal portion 33. The outer edge 33B, which is the edge of the seal portion 34, and the outer edge 34B, which is the edge opposite to the inner edge 34A in the fourth seal portion 34, define the outer shell of the steamable flat pouch 10.

The width of each of the seal portions 31 to 34 can be arbitrarily selected. The width of each of the seal portions 31 to 34 is the length between the inner edges 31A to 34A and the outer edges 31B to 34B in the normal line of the center line of each of the seal portions 31 to 34. The center line of each of the seal portions 31 to 34 is a virtual line segment passing between the inner edges 31A to 34A and the outer edges 31B to 34B. When the width of each of the seal portions 31 to 34 is different for each portion, for example, the maximum width or the average of the widths of a plurality of portions in each of the seal portions 31 to 34 represents the width of the seal portion.

The dimensions in the first direction and the dimensions in the second direction of the steamable flat pouch 10 are preferably determined, for example, in relation to the amount of the contents C to be contained and the portability of the steamable flat pouch 10. .. The dimension of the steamable flat pouch 10 in the first direction is the length between the outer edge 33B of the third seal portion 33 and the outer edge 34B of the fourth seal portion 34 in the line segment orthogonal to the second direction. When the dimensions of the steamable flat pouch 10 in the first direction are different for each part, for example, the maximum dimension or the average of the dimensions of a plurality of parts represents the dimension of the steamable flat pouch 10 in the first direction. According to one example, the size of the steamable flat pouch 10 in the first direction is 130 mm. The dimension of the steamable flat pouch 10 in the second direction is the length between the outer edge 31B of the first seal portion 31 and the outer edge 32B of the second seal portion 32 in the line segment orthogonal to the first direction. When the dimensions of the steamable flat pouch 10 in the second direction are different for each part, for example, the maximum dimension or the average of the dimensions of a plurality of parts represents the dimension of the steamable flat pouch 10 in the second direction. According to one example, the size of the steamable flat pouch 10 in the second direction is 135 mm.

The opening 40 (see FIG. 3) is formed between the lower portion 21A of the first sheet 21 and the lower portion 22A of the second sheet 22 so that the content C can be filled in the accommodation space 10C. In the steamable flat pouch 10 shown in FIG. 1, the opening 40 is closed by the second seal portion 32. The steamable flat pouch 10 with the opening 40 closed (hereinafter, “the steamable flat pouch 10 after closing”) includes the pouch body 10A and the separation portion 10B. The pouch body 10A and the separating portion 10B are separated by a cutting line 51 constituting the guide portion 50. The pouch body 10A is a portion that houses the content C. The separation portion 10B is a part of each of the sheets 21 and 22 including the first seal portion 31, and is a portion that the user separates from the pouch body 10A in order to take out the content C from the accommodation space 10C.

The guide portion 50 is formed between the pouch main body 10A and the separating portion 10B so that the sheets 21 and 22 can be easily cut when the separating portion 10B is separated from the pouch main body 10A. The guide portion 50 includes a cut line 51 and a notch 52. The cut line 51 is a set of perforations formed in the inner portions 23 of the respective seal portions 33 and 34 and the respective sheets 21 and 22, and is formed in a straight line. The notch 52 is formed in at least one of the third seal portion 33 and the fourth seal portion 34 so that the tip end portion of the notch 52 is located on the virtual line extending the cut line 51. FIG. 1 shows an example in which a notch 52 is formed in each of the third seal portion 33 and the fourth seal portion 34.

The steamable flat pouch 10 is heated by a heating means to heat the content C. An example of a heating means is a microwave oven. As the steaming type flat pouch 10 is heated, water vapor is generated from the content C. Since the storage space 10C of the steaming type flat pouch 10 after closing is closed by the seal portion 30, the pressure in the storage space 10C increases with the generation of water vapor.

The steam-permeating seal portion 60 is a portion of the inner portion 23 where the innermost layer of the first sheet 21 and the innermost layer of the second sheet 22 are joined, and is configured to be peeled off as the pressure of the accommodation space 10C increases. ing. In a preferred example, the steam seal portion 60 is configured to peel off when the pressure in the accommodation space 10C rises to a pressure within a predetermined pressure range. When the steaming seal portion 60 is peeled off, the steam discharging unit 70 communicates the accommodating space 10C with the outside of the steaming type flat pouch 10 and discharges the steam generated from the content C to the outside of the steaming type flat pouch 10. do. By discharging water vapor from the steam discharge unit 70, an increase in pressure in the accommodation space 10C is suppressed, and the rupture of the steaming type flat pouch 10 is avoided. The steam discharge portion 70 is provided inside the outer shell of the steaming seal portion 60.

The steaming seal portion 60 is provided so as to be connected to the seal portion 30. Since the steaming seal portion 60 is connected to the seal portion 30, the formation position of the steam discharge portion 70 on the sheet 20 can be brought closer to the seal portion 30. Since the steam-permeating seal portion 60 is separated from the seal portion 30, the steam discharge portion 70 can be formed at a position away from the seal portion 30 on the sheet 20. The number of the steam sealing portions 60 provided on the inner portion 23 is one or a plurality. The steaming seal portion 60 is provided at an arbitrary position on the inner portion 23. In a preferred example, the steam sealing portion 60 is provided at a location where strong stress concentration occurs when the pressure in the accommodation space 10C increases. In the first example, the steam-permeable seal portion 60 is provided at a position facing the center of the first seal portion 31 in the longitudinal direction in the separation portion 10B. In the first example, when the separating portion 10B is separated from the pouch main body 10A, the steam sealing portion 60 does not remain in the pouch main body 10A, and when the content C is taken out from the accommodation space 10C, the content C is the steam discharging portion. It does not leak from 70. In the second example, the steam sealing portion 60 is provided on the pouch body 10A.

FIG. 2 is an enlarged view of the steam sealing portion 60 and its surroundings. The outer shape of the steam sealing portion 60 can take various shapes. Examples are triangles, triangle-like shapes, trapezoids, trapezoid-like shapes, and convex shapes. In the illustrated example, the outer shape of the steam sealing portion 60 is an isosceles triangle. The sides constituting this isosceles triangle are the first side 60A and the second side 60B which are equal sides, and the third side 60C which is the base side. The seal width XA of the steam-permeating seal portion 60 is the distance between the first side 60A and the second side 60B in the first direction.

When the pressure in the accommodation space 10C rises due to the heating of the steaming type flat pouch 10, the steaming seal portion 60 peels off, and the peeling of the steaming seal portion 60 progresses as the pressure rises. When the peeling of the steaming seal portion 60 reaches the steam discharging portion 70, the accommodation space 10C and the outside of the steaming type flat pouch 10 communicate with each other via the steam discharging portion 70. The communication area of the steam discharge unit 70, which is the area of the portion of the steam discharge unit 70 that directly communicates with the accommodation space 10C, becomes wider as the peeling of the steaming seal portion 60 progresses. Assuming that the pressure in the accommodation space 10C is constant, the wider the communication area of the steam discharge unit 70, the larger the flow rate of water vapor discharged to the outside of the steaming type flat pouch 10 via the steam discharge unit 70. .. The communication area is 0 when the steaming seal portion 60 is not peeled off and when the steaming seal portion 60 is not peeled off to reach the steam discharge portion 70. When the entire peripheral portion of the steam discharging portion 70 of the steaming sealing portion 60 is peeled off, the communication area becomes the widest.

The steam sealing unit 60 includes a leading peeling portion 61 including a portion to be peeled first in the steam sealing portion 60, and a trailing peeling portion 62 including a portion to be finally peeled in the steam sealing portion 60. In the illustrated example, the portion of the steam sealing portion 60 that is first peeled off is a part or all of the third side 60C. The final peeling portion of the steam sealing portion 60 is the apex 60D. The seal width XA of the trailing peeling portion 62 with respect to the peeling progress direction of the steam sealing portion 60 is narrower than the seal width XA of the preceding peeling portion 61 in the peeling progress direction of the steam sealing portion 60.

The preceding peeling portion 61 includes, for example, the following portion in the steam sealing portion 60. In the first example, the leading peeling portion 61 includes a portion from the third side 60C of the steaming seal portion 60 to the steam discharging portion 70. When the range of the preceding peeling portion 61 is the first example, the steam discharging portion 70 does not communicate with the accommodation space 10C until the peeling of the steaming seal portion 60 reaches the trailing peeling portion 62. Immediately after the peeling of the steaming seal portion 60 reaches the steam discharge portion 70, the communication area is relatively small, so that the force acting to peel the steaming seal portion 60 is high, and the preceding peeling portion 61 can be peeled. Subsequently, the peeling at the trailing peeling portion 62 proceeds smoothly. In the second example, the leading peeling portion 61 includes a portion from the third side 60C to the end portion of the steam discharging portion 70 on the accommodation space 10C side (hereinafter, “inner end portion of the steam discharging portion 70”). When the range of the preceding peeling portion 61 is the second example, the inner end portion of the steam discharging portion 70 directly communicates with the accommodation space 10C in a state where the entire preceding peeling portion 61 is peeled off, but the steam discharging portion 70 Since the communication area is relatively small, the pressure in the accommodation space 10C is maintained at a relatively high level. Therefore, the force acting to peel off the steam sealing portion 60 is high, and the peeling in the trailing peeling portion 62 proceeds smoothly following the peeling of the leading peeling portion 61.

The steam discharge unit 70 may have various configurations. According to the first example, the steam discharge portion 70 is a notch or a hole penetrating the first sheet 21. According to the second example, the steam discharge portion 70 is a notch or a hole that does not penetrate the first sheet 21. The depth of the cut or the depth of the hole in the second example is such that when the steaming seal portion 60 is peeled off, the portion of the first sheet 21 corresponding to the steam discharge portion 70 is broken. Is preferable. The steam discharge unit 70 can take various outer shapes. According to the first example, the outer shape of the steam discharge portion 70 is a rectangle extending in the first direction or the second direction. According to the second example, the outer shape of the steam discharge portion 70 is an equilateral triangle, an isosceles triangle, a square, or a polygon of a pentagon or more. When the peeling of the steaming seal portion 60 does not reach the hole or notch of the steam discharge portion 70, the hole or notch does not communicate the accommodation space 10C with the outside. When the peeling of the steam sealing portion 60 reaches the hole or notch, the hole or notch communicates with the accommodation space 10C and the outside, and as the peeling progresses, the portion of the portion communicating with the accommodation space 10C and the outside in the hole or notch. The communication area, which is the area, expands.

In the first example or the second example, when the outer shape of the steam discharge portion 70 is formed so as to extend in the peeling progress direction of the steaming seal portion 60 (hereinafter, “peeling progress direction”), it matches with the progress of the peeling. The communication area gradually increases. Therefore, it is suppressed that the flow rate of water vapor discharged from the accommodation space 10C to the outside suddenly increases, and the peeling of the steaming seal portion 60 easily reaches the apex 60D which is the end portion of the trailing peeling portion 62.

The ratio of the dimension HB of the steam discharge part 70 in the peeling progress direction to the dimension HA of the steaming seal part 60 in the peeling progress direction (hereinafter referred to as “the discharge part ratio RA”) is the ease with which steam is discharged and the steam discharge part 70. It is preferable that it is determined from the relationship with the difficulty of foreign matter entering the vehicle. The formula for obtaining the discharge part ratio RA is “RA = (HB / HA) × 100”. The dimension HA is, for example, the height of the heat-permeable seal portion 60 when the outer shape of the heat-permeable seal portion 60 is triangular. The dimension HB is, for example, the length of the long side of the steam discharge portion 70 when the outer shape of the steam discharge portion 70 is rectangular. A preferable example of the maximum value of the discharge part ratio RA is 62.5%. A more preferred example of the maximum value of the discharge rate RA is 25%. When the discharge part ratio RA is 62.5% or less, it is difficult for foreign matter to enter the steam discharge part 70. When the discharge part ratio RA is 25% or less, it is more difficult for foreign matter to enter the steam discharge part 70. A preferable example of the minimum value of the discharge part ratio RA is 12.5%. A more preferred example of the minimum value of the discharge rate RA is 25%. When the discharge part ratio RA is 12.5% or more, water vapor is appropriately discharged from the steam discharge part 70 when the steaming seal part 60 is peeled off. When the discharge part ratio RA is 25% or more, water vapor is more appropriately discharged from the steam discharge part 70 when the steaming seal part 60 is peeled off.

FIG. 3 is a steamable flat pouch 10 before the opening 40 is closed (hereinafter, “steamable flat pouch 10 before closing”). The content C (see FIG. 1) is charged into the accommodation space 10C through the opening 40 of the steam-permeable flat pouch 10 before closing. The second seal portion 32 is formed by heat-sealing the planned seal portion 80, which is scheduled to form the second seal portion 32 after the content C is charged, so that the second seal portion 32 is formed, and the second seal portion 32 is formed after the closure as shown in FIG. A steamable flat pouch 10 is obtained.

An example of how to use the steamable flat pouch 10 will be described with reference to FIG.
A closed steaming type flat pouch 10 is arranged in a heating means (not shown) such as a microwave oven so that the second sheet 22 is below the first sheet 21, and is heated by the heating means. After the heating is completed, the sheets 21 and 22 are torn from the tip of the notch 52, and a force is applied to the sheets 21 and 22 so that the tearing of the sheets 21 and 22 proceeds along the cut line 51. By separating the separating portion 10B from the pouch body 10A, the content C is taken out from the accommodating space 10C to the outside of the steamable flat pouch 10.

The operation of the steamable flat pouch 10 will be described with reference to FIGS. 4 to 6.
When the closed steamable flat pouch 10 is heated by the heating means, in one example, the second sheet 22 is located below and the first sheet 21 on which the steam discharge portion 70 is formed is located above. It is set. When the closed steaming type flat pouch 10 is heated in that state, the pressure of the accommodation space 10C rises due to the water vapor generated from the content C, and the force acting to peel off the steaming seal portion 60 is passed. It covers the steam seal portion 60. When the pressure in the accommodating space 10C rises to a certain pressure, the peeling of the steam sealing portion 60 starts from the leading peeling portion 61, and the peeling of the steam sealing portion 60 proceeds toward the trailing peeling portion 62. As shown in FIG. 4, when the peeling of the steaming seal portion 60 reaches the steam discharge portion 70, the accommodation space 10C and the outside communicate with each other by the steam discharge portion 70, so that the steam in the accommodation space 10C is discharged from the steam discharge portion. It is discharged to the outside via 70. Therefore, the increase in the pressure in the accommodation space 10C is suppressed, and the force acting to peel off the steam sealing portion 60 is reduced. However, since the seal width XA of the trailing peeling portion 62 is narrower than the sealing width XA of the leading peeling portion 61, it is unlikely that the steaming seal portion 60 will stop peeling before the end of the trailing peeling portion 62. .. As shown in FIG. 5, when the peeling of the steam sealing portion 60 reaches the end of the trailing peeling portion 62, as shown in FIG. 6, the steam sealing portion 60 of the first sheet 21 is used. The joined portion moves upward so as to be separated from the second sheet 22 and the content C. In the steaming type flat pouch 10, the steaming seal portion 60 is formed in the inner portion 23, and the steam discharging portion 70 is formed in the steaming seal portion 60, so that the first sheet 21 moves upward. As a result, the steam discharge unit 70 also moves upward so as to be separated from the second sheet 22 and the content C. Therefore, the content C is less likely to leak when the water vapor is discharged.

(Example)
Using the samples of Examples and Comparative Examples, the inventor of the present application conducted a test to confirm the relationship between the configurations of the steaming seal portion 60 and the steam discharging portion 70 and the seal peeling performance and the steaming performance. FIG. 7 shows the test conditions of Comparative Examples and Examples relating to the test. FIG. 8 shows the test results. In the following description, for convenience of explanation, the same reference numerals are given to the parts in common with the sample of the example in the sample of the comparative example. The sample of the example is a steamable flat pouch 10 according to the embodiment. The sample of the comparative example is a steamable flat pouch 10 having a configuration different from that of the steamable flat pouch 10 of the example. The steamable flat pouch 10 of each comparative example is a steamable flat pouch of the example in that the seal width XA of the trailing peeling portion 62 in the peeling progress direction is wider than the seal width XA of the preceding peeling portion 61 in the peeling progress direction. Unlike 10, it has the same configuration as the steaming type flat pouch 10 of the embodiment in other respects.

The specifications of the samples of each example and each comparative example are as follows. The material forming the outermost layer of each of the sheets 21 and 22 is polyethylene terephthalate. The thickness of the outermost layer is 12 μm. The material forming the intermediate layer of each of the sheets 21 and 22 is nylon. The thickness of the intermediate layer is 15 μm. The material forming the innermost layer of each of the sheets 21 and 22 is unstretched propylene. The thickness of the innermost layer is 60 μm. The dimension of the steamable flat pouch 10 in the first direction is 130 mm. The dimension of the steamable flat pouch 10 in the second direction is 135 mm. The number of the steam sealing portions 60 provided on the inner portion 23 is 1. The position where the steam-permeating seal portion 60 is provided is a position in the separation portion 10B facing the center of the first seal portion 31 in the longitudinal direction.

The outer shape of the steam-permeable seal portion 60 of the samples of Comparative Example 1 and Comparative Example 5 is a circle. The radius of the circle is 5 mm. The outer shape of the steam-permeable seal portion 60 of the samples of Comparative Example 2 and Comparative Example 6 is square. The length of one side of the square is 10 mm. The outer shape of the steam-permeable seal portion 60 of the samples of Comparative Example 3 and Comparative Example 7 is a trapezoid in which the seal width XA becomes wider from the center of the inner portion 23 toward the first seal portion 31, that is, in the peeling progress direction. .. The length of the upper base of the trapezoid is 10 mm, the length of the lower base is 20 mm, and the height is 10 mm. The outer shape of the steam-permeable seal portion 60 of the samples of Comparative Example 4 and Comparative Example 8 is an equilateral triangle in which the seal width XA becomes wider from the center of the inner portion 23 toward the first seal portion 31, that is, in the peeling progress direction. be. The length of one side of an equilateral triangle is 10 mm.

The outer shape of the steam-permeable seal portion 60 of the samples of Examples 1 and 3 is a triangle in which the seal width XA narrows from the center of the inner portion 23 toward the first seal portion 31, that is, in the peeling progress direction. .. The length of one side of an equilateral triangle is 10 mm. The outer shape of the steam-permeable seal portion 60 of the samples of Examples 2 and 4 is a trapezoid in which the seal width XA narrows from the center of the inner portion 23 toward the first seal portion 31, that is, in the peeling progress direction. .. The length of the upper base of the trapezoid is 10 mm, the length of the lower base is 20 mm, and the height is 10 mm.

The dimensions of the steam discharge portions of the samples of Comparative Examples 1 to 4 and the samples of Examples 1 and 2 in the first direction are 1 mm. The dimensions of the steam discharge portions of the samples of Comparative Examples 1 to 4 and the samples of Examples 1 and 2 in the second direction are 3 mm. The dimensions of the steam discharge portions of the samples of Comparative Examples 5 to 8 and the samples of Examples 3 and 4 in the first direction are 3 mm. The dimensions of the steam discharge portions of the samples of Comparative Examples 5 to 8 and the samples of Examples 3 and 4 in the second direction are 1 mm.

In order to evaluate the seal peeling performance, it was visually confirmed whether or not the entire steamable seal portion 60 was peeled off when the steamable flat pouch 10 after closing was heated by the heating means. The state in which the entire steam-permeable seal portion 60 is peeled off is a state in which the portions constituting the inner portion 23 of the first sheet 21 and the second sheet 22 are not joined. It is evaluated that the seal peeling performance is good when the entire steam-permeable seal portion 60 is peeled off, and it is evaluated that the seal peeling performance is not good when at least a part of the steam-permeable seal portion 60 is not peeled off. bottom.

In order to evaluate the steaming performance, if the steamed flat pouch 10 after closing is heated by a heating means and steam is discharged from the steam discharge part 70, is the content C leaking from the steam discharge part 70? It was visually confirmed whether or not it was present. The state in which the content C does not leak from the steam discharge unit 70 is a state in which the content C does not adhere to the surface of the first sheet 21 and around the steamable flat pouch 10. The state in which the content C is leaking from the steam discharge unit 70 is a state in which the content C is attached to at least one of the surface of the first sheet 21 and the periphery of the steamable flat pouch 10. The number of trials of the test is three. Content C is the source of beef bowl. Gyudon base includes beef, vegetables, and soup stock. The weight of the content C is 80 g. The output of the microwave oven is 600W. The heating time of the microwave oven is 1 minute and 20 seconds.

In the item of seal peeling performance in FIG. 8, "○" indicates the case where the entire steam-permeable seal portion 60 is peeled off, and "x" indicates the case where at least a part of the steam-permeable seal portion 60 is not peeled off. .. In the item of steaming performance in FIG. 8, "○" indicates that the content C does not leak when steam is discharged from the steam discharge unit 70, and "x" indicates that steam is discharged from the steam discharge unit 70. In this case, the content C is leaking.

According to the steamable flat pouch 10 of the embodiment, it was confirmed that when the steamable flat pouch 10 after closing was heated by the heating means, the entire steamable seal portion 60 was peeled off and the contents C were less likely to leak out. Was done. Further, it was confirmed that when the steam discharge portion 70 had a shape extending in the peeling progress direction, the entire steaming seal portion 60 was peeled off, and the contents C were more difficult to leak.

(Modification example)
The description of the above embodiment is an example of possible forms of the steamable flat pouch according to the present invention, and is not intended to limit the form. The steamable flat pouch according to the present invention may take, for example, a modification of the above embodiment shown below and a combination of at least two modifications that do not contradict each other.

-The configuration of the steam sealing portion 60 can be arbitrarily changed. FIG. 9 is an example of a modification of the steam sealing portion 60. The steam sealing portion 60 includes a leading peeling portion 61 and a trailing peeling portion 62. The outer shape of the leading peeling portion 61 is, for example, a semicircle. The outer shape of the trailing peeling portion 62 is an isosceles triangle in which the seal width XA narrows in the peeling progress direction. The position where the steam discharge portion 70 is provided is arbitrary inside the outer shell of the steaming seal portion 60. According to the first example, the steam discharge portion 70 is provided straddling the leading peeling portion 61 and the trailing peeling portion 62. According to the second example, the steam discharge portion 70 is provided only in the trailing peeling portion 62 of the steaming seal portion 60.

FIG. 10 is an example of another modification of the steam sealing portion 60. The steaming seal portion 60 includes an unsealed portion 71 provided so as to surround the steam discharge portion 70. The unsealed portion 71 is a portion where the first sheet 21 and the second sheet 22 are not joined inside the outer shell of the steam sealing portion 60. When the first sheet 21 and the second sheet 22 are joined to form the steaming seal portion 60 so that the unsealed portion 71 is formed after the steam discharge portion 70 is formed on the first sheet 21. Since the heat shrinkage around the steam discharge portion 70 of the first sheet 21 is suppressed, the steam discharge portion 70 is likely to be maintained at a specified size.

10: Steaming type flat pouch 10C: Storage space 20: Sheet 23: Inner part 30: Seal part 50: Guide part 60: Steaming seal part 61: Leading peeling part 62: Trailing peeling part 70: Steam discharge part C :Contents

Claims (7)

A seal portion that seals a sheet containing the first sheet and the second sheet that are overlapped so as to form an accommodation space for accommodating the contents.
In the inner part of the sheet, which is the inner part of the seal part, a steam-permeable seal part that joins a part of the sheet so as to be connected to the seal part.
In the first sheet, the accommodation space and the outside are communicated with each other when the steaming seal portion is peeled off so that the accommodation space and the outside are not communicated with each other when the steaming seal portion is not peeled off. It is provided with a steam discharge part formed in the steaming seal part.
The steam-sealed portion includes a leading peeled portion including a portion that is first peeled off in the steam-sealed portion as the pressure in the accommodation space increases, and a subsequent peeling portion that includes a portion that is finally peeled off in the steam-sealed seal portion. The width of the trailing peeling portion with respect to the peeling progress direction of the steam sealing portion is narrower than the width of the preceding peeling portion with respect to the peeling progress direction.
A steaming type flat pouch configured so that when the peeling of the steaming seal portion reaches the last peeling portion of the steaming seal portion, the steam discharging portion moves away from the second sheet. .. The steam-permeable flat pouch according to claim 1, wherein the trailing peeling portion is formed so that the width becomes narrower toward the side in which the peeling proceeds. The steam-permeable flat pouch according to claim 1 or 2, wherein the steam discharge portion includes a notch or a hole penetrating one of the stacked sheets and is formed so as to extend in the direction in which the peeling proceeds. Further provided with a guide portion constituting a guide for separating the sheet and a part of the seal portion in order to open the accommodation space closed by the seal portion.
The steaming type flat pouch according to any one of claims 1 to 3, wherein the steaming seal portion is provided in a portion of the sheet separated by the guide portion. The steaming type according to any one of claims 1 to 4, wherein the dimension of the steam discharge portion in the peeling progress direction is 12.5% or more of the dimension of the steaming seal portion in the peeling progress direction. Flat pouch. The steaming type according to any one of claims 1 to 5, wherein the dimension of the steam discharge portion in the peeling progress direction is 62.5% or less of the dimension of the steaming seal portion in the peeling progress direction. Flat pouch. The steamable flat pouch according to any one of claims 1 to 6, further comprising the contents housed in the storage space.

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