Steam penetrative pouch

Abstract

To provide a steam penetrative pouch an unsealing portion of which can beautifully be torn straight with hands and out of which its contents can easily be taken.SOLUTION: A steam penetrative pouch 10 comprises opposite body member sheets 20 and a bottom member sheet, has a storage space 11 storing the contents by sealing peripheral edges of a left side surface and a right side surface and a bottom surface and, after filling contents 15, hermetically sealing an upper surface, and includes, in at least one of seal portions of the left and right side surfaces, a steam penetrative portion 60 for allowing steam in the storing space to escape during heating and an unsealing portion 50 formed on a bottom-surface side or an upper-surface side of the steam penetrative portion so as to be substantially parallel to the bottom surface. The body member sheets and the bottom member sheet each includes an outermost layer and a sealant layer. The sealant layer of each of the body member sheets is composed of a material excellent in heat resistance and ability to easily be torn in a width direction. The sealant layer of the bottom member sheet is composed of a material excellent in heat resistance and ability to spread at the bottom.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a steam-permeable pouch whose opening portion can be easily torn by hand or the like and which can also be used as a container for eating after opening. [Background technology]

[0002] For example, microwave pouches that contain contents to be heated, such as retort foods and frozen foods, are widely used. When such pouches are heated in a microwave oven, the moisture in the contents evaporates as the pouch is heated, and the pressure inside the pouch increases. If the pressure inside the pouch increases, the pouch may break, causing the contents to scatter and soil the microwave oven. Therefore, steam-passing pouches equipped with a steam release mechanism are known that release the pressure inside the pouch that increases with heating to the outside.

[0003] The steam-passing pouch includes a sheet that is sealed to form a storage space capable of storing contents, and a steam-passing portion in which a portion of the sheet is sealed to open as the pressure in the storage space increases. When the pressure in the storage space increases to a certain level by heating, the seal that constitutes the steam-passing portion peels off, and a passage that connects the storage space to the outside space is formed in the steam-passing portion. As a result, moisture in the storage space passes through the passage formed in the steam-passing portion and is discharged to the outside of the pouch, suppressing the increase in pressure in the storage space.

[0004] Patent Document 1 discloses a microwave pouch, which is an example of a conventional steam-permeable pouch. As shown in Patent Document 1, this microwave pouch includes a laminated sheet. The laminated sheet includes a base layer, a printed layer, other layers, and a sealant layer. When heating of the microwave pouch containing the contents by the heating means is completed, the laminated sheet is torn from the opening portion, and the contents are removed from the storage space. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-127257 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the microwave pouch described in Patent Document 1, when attempting to tear the laminated sheet from the opening part by hand, the innermost sealant layer stretches during the tearing process, making it impossible to tear in a straight line, or the tearing part may become frayed or wavy, resulting in an insufficient opening and making it difficult to easily remove the contents from the opening part.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide a steam-permeable pouch whose opening portion can be torn linearly and neatly by hand or the like, and from which the contents can be easily removed. [Means for solving the problem]

[0008] According to claim 1 of the present invention, the bag comprises opposing body member sheets and a bottom member sheet folded into the bottom surface, The left side surface, the right side surface and the bottom surface are sealed at their periphery, and the top surface is then sealed after the contents are filled, thereby forming a storage space for storing the contents; A steam-passing pouch comprising a steam passage portion for allowing steam in the storage space to escape when heated, in at least one of the left and right side seal portions, and a tear-open portion on the bottom or top side of the steam passage portion, the tear-open portion being approximately parallel to the bottom surface, The body member sheet and the bottom member sheet each include at least an outermost layer and a sealant layer, The sealant layer of the body member sheet is made of a material having excellent heat resistance and tearability in the width direction, The sealant layer of the base member sheet is made of a material that is excellent in heat resistance and bottom opening property.

[0009] When the steam-passing pouch is heated with the contents contained in the storage space, a passage that connects the storage space to the outside space is formed in the steam-passing section as the pressure in the storage space increases. Therefore, water vapor in the storage space passes through the passage formed in the steam-passing section and is discharged to the outside of the steam-passing pouch, suppressing an increase in pressure in the storage space. In addition, since the sealant layer of the body member sheet is made of a material that is easily tearable in the width direction, the sheet can be easily torn in the width direction. Therefore, the contents can be easily removed from the torn part of the body member sheet. In addition, since the sealant layer of the bottom member sheet is made of a material that has appropriate stiffness and is bottom-openable, the suitability for filling as a container can be ensured.

[0010] According to a second aspect of the present invention, the sealant layer of the body member sheet contains 3 to 10 parts by weight of a low crystalline ethylene-based elastomer with respect to 100 parts by weight of a propylene-ethylene block copolymer, and the low crystalline ethylene-based elastomer has a density of 0.865 to 0.890 g / cm. 3 and the heat absorption amount at the time of melting, as specified in JIS standard 7122, is within the range of 5 to 30 J / g, and the sealant layer of the bottom member sheet is made of non-oriented polypropylene. Polypropylene is a resin with excellent heat resistance, and can be suitably used as a material for microwave pouches that require boiling and retorting suitability.

[0011] In addition, the sealant layer of the body member sheet has easy tearing properties in the width direction, so the sheet can be easily torn in the width direction. Also, short thread-like hairs may remain in the torn area, but this phenomenon rarely occurs with polypropylene. Therefore, the contents can be easily removed from the torn area of ​​the sheet.

[0012] The sealant layer of the bottom sheet is made of non-oriented polypropylene. Non-oriented polypropylene is a film made by molding polypropylene material without stretching it, and since it stretches when pulled, it is not easily torn and is not suitable for the body member, but it is flexible and has a bottom opening property, so it is suitable for filling and does not tear easily even when pulled.

[0013] According to claim 3 of the present invention, both or at least one of the body member sheet and the bottom member sheet further includes an intermediate layer laminated between the outermost layer and the sealant layer, thereby increasing the strength of the steam-passing pouch.

[0014] According to claim 4 of the present invention, the intermediate layer is made of a material having excellent heat resistance and tearability in the width direction. Since the intermediate layer is made of a material having excellent tearability in the width direction, the sheet can be easily torn. Therefore, the contents can be easily removed from the torn part of the sheet.

[0015] According to claim 5 of the present invention, the opening portion has a notch in at least one of the left and right side seal portions, and further includes a guide portion that guides the cutting of the sheet from the right end of the left side seal portion to the left end of the right side seal portion. With the above steam-permeable pouch, the sheet can be easily torn along the guide portion with the notch as the starting point for tearing. Therefore, the contents can be easily removed from the torn portion of the sheet.

[0016] According to claim 6 of the present invention, the guide portion includes a tear line provided in the intermediate layer. According to the steam-permeable pouch, even when the intermediate layer is provided, the sheet can be easily torn. Therefore, the contents can be easily removed from the torn portion of the sheet. Effect of the Invention

[0017] According to the steam-permeable pouch of the present invention, the opening portion can be torn by hand or the like in a straight line and neatly, and the contents can be easily removed. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a front view of a steam-passing pouch showing an example of an embodiment of the present invention. [Diagram 2] FIG. 4 is a cross-sectional view showing the layer structure of a body member sheet and a bottom member sheet. [Diagram 3] FIG. 4 is an enlarged view of the steam passage portion and its surroundings in an open state. [Figure 4] FIG. 2 is a front view of the steam-permeable pouch in an opened state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An example of an embodiment of the present invention will be described below. FIG. 1 shows an example of a steam-passing pouch 10 capable of storing a content 15 suitable for heating and discharging steam generated from the content 15. The content 15 is a heated object that generates water vapor when heated. An example of the content 15 is food. An example of the food is a food having fluidity such as stew and soup. The steam-passing pouch 10 is configured so that the content 15 can be stored for a long period of time while maintaining its quality. Examples of shapes that the steam-passing pouch 10 can take include freestanding types such as a standing type and a gusset type. The shape of the steam-passing pouch 10 exemplified in FIG. 1 is a standing type. Hereinafter, the left-right direction of the steam-passing pouch 10 in a front view of the steam-passing pouch 10 is referred to as the standard width direction, and the direction perpendicular to the standard width direction is referred to as the standard height direction.

[0020] The steam-permeable pouch 10 includes a body member sheet 20, a bottom member sheet 23, a top seal portion 31, a bottom seal portion 32, a right side seal portion 33, a left side seal portion 34, an opening portion 50, and a steam-permeable portion 60. The body member sheet 20 is made up of a front sheet 21 and a back sheet 22. The front sheet 21 and the back sheet 22 face each other so that a storage space 11 for storing contents 15 is formed between the sheets 21, 22. The bottom member sheet 23 is folded around its periphery and sealed to close the gap between the bottom of the front sheet 21 and the bottom of the back sheet 22.

[0021] The body member sheet 20 (21, 22) and the bottom member sheet 23 have a layered structure in which a plurality of layers are laminated. FIG. 2(a) is a cross-sectional view showing the layer structure of the body member sheet, and FIG. 2(b) is a cross-sectional view showing the layer structure of the bottom member sheet. The body member sheet 20 (21, 22) includes an outermost layer 20A, an intermediate layer 20B, a sealant layer 20C, a first adhesive layer 20D, and a second adhesive layer 20E. Similarly, the bottom member sheet 23 includes an outermost layer 23A, an intermediate layer 23B, a sealant layer 23C, a first adhesive layer 23D, and a second adhesive layer 23E. An example of a manufacturing method for each of the sheets 21 to 23 is dry lamination. The first adhesive layer of each of the sheets 21 to 23 is provided between the outermost layer and the intermediate layer, and the second adhesive layer is provided between the intermediate layer and the sealant layer.

[0022] The outermost layer 20A of the body member sheet 20 (21, 22) is excellent mainly in gas barrier properties, printability, and heat resistance. The outermost layer 20A is, for example, a transparent vapor deposition layer. An example of a material constituting the outermost layer 20A is polyethylene terephthalate (hereinafter referred to as "vapor deposition PET") on which an inorganic thin film is vapor-deposited. The middle layer 20B is excellent mainly in heat resistance and moisture resistance. The material constituting the middle layer 20B is nylon (hereinafter referred to as "easy-to-cut Ny") that is easily torn in the width direction of the body member sheet 20. Hereinafter, the orientation direction of the material constituting each of the sheets 21, 22 is referred to as the MD (Machine Direction) direction, and the direction perpendicular to the MD direction is referred to as the TD (Transverse Direction) direction. The MD direction of each of the sheets 21, 22 is the direction along the standard width direction. The TD direction of each of the sheets 21, 22 is the direction along the standard height direction. An example of a material constituting the first adhesive layer 20D is a polyester-based adhesive. An example of a material that constitutes the second adhesive layer 20E is a polyester-based adhesive.

[0023] With regard to the bottom member sheet 23, the outermost layer 23A is made of the same material as the outermost layer 20A of the body member sheet 20, but an example of a material for the middle layer 23B is non-stretchable nylon that is not easily cut.

[0024] The sealant layer 20C of the body member sheet 20 has excellent heat resistance, heat sealability, and impact resistance. An example of a material constituting the sealant layer 20C is non-oriented polypropylene (hereinafter referred to as "easy-to-cut CPP") that has excellent tearability in the MD direction.

[0025] "Excellent tear resistance in the MD" refers to, for example, a tear strength of 1.2 N or less according to the trouser tear method specified in JIS standard K7128-1. In the trouser tear method, a rectangular test piece 50 mm long in the TD direction and 150 mm long in the MD direction was cut at a 75 mm cut in the center, and the tear strength in the MD direction was measured at a speed of 200 mm / min in a thermostatic chamber at 23°C.

[0026] The easy-to-cut CPP contains, for example, 3 to 10 parts by weight of a low-crystalline ethylene-based elastomer for 100 parts by weight of a propylene-ethylene block copolymer. The low-crystalline ethylene-based elastomer has a density of, for example, 0.865 to 0.890 g / cm 3 and the heat absorption at the time of melting, as specified in JIS standard 7122, is in the range of 5 to 30 J / g.

[0027] The sealant layer 23C of the base member sheet 23 has excellent heat resistance, heat sealability, and flexibility, and is suitable for bottom opening. In addition, the sealant layer 23C is a non-stretched film, which has the property of stretching when pulled and is not easily cut.

[0028] The sealed portions 31-34 shown in Fig. 1 join the sheets 21-23 together so that the sheets 21-23 do not separate. One example of a method for forming the sealed portions 31-34 is heat sealing. The outer shape of the steam-permeable pouch 10 as viewed from the front can be selected arbitrarily. In the example shown in Fig. 1, the outer shape of the steam-permeable pouch is rectangular.

[0029] The opening section 50 has a notch 51 in at least one of the left and right side seal sections, and a guide section 52 is provided on the body member sheet 20 at the same height as the notch 51 in the standard height direction, for guiding the cutting of the body member sheet 20 from the right end of the left side seal section to the left end of the right side seal section. The opening section 50 (notch 51, guide section 52) can be provided at any position in the standard height direction. In one example shown in FIG. 1, the opening section 50 is provided between the steam passage section 60 and the bottom member sheet 23 in the standard height direction. In a preferred example, the opening section 50 is provided at a position closer to the steam passage section 60 than the bottom member sheet 23 in the standard height direction. In another example, the opening section 50 is provided between the steam passage section 60 and the top seal section 31 in the standard height direction.

[0030] Guide portion 52 is a set of perforations formed on body member sheet 20, and is formed along the MD direction of body member sheet 20. Notch 51 is formed in at least one of right side seal portion 33 and left side seal portion 34 so that the tip of notch 51 is positioned on an imaginary line extending from guide portion 52. Fig. 1 shows an example in which notch 51 is formed in left side seal portion 34.

[0031] The tearing portion 50 in which the guide portion 52 is formed has a lower tear strength than other portions of the body member sheet 20 in which the guide portion 52 is not formed. Therefore, when a force is applied to the tearing portion 50 in a direction along the guide portion 52, the body member sheet 20 is easily torn along the guide portion 52. The guide portion 52 includes a plurality of cuts 52A formed discontinuously in the standard width direction. The means for forming the guide portion 52 is, for example, a perforation machine.

[0032] The shape of the incision 52A may be any of straight lines, curved lines, perforated lines, dashed lines, etc., and the number of incisions may be one or more in the standard height direction. In the present invention, it is sufficient that the incision 52A portion is weakened and acts as a cut in the opening portion 50.

[0033] In a preferred example, the cut 52A does not penetrate all three layers, namely, the outermost layer 20A, the intermediate layer 20B, and the sealant layer 20C, that constitute the body member sheet 20, and is formed in one or two of the three layers. Because the cut 52A does not penetrate the three layers of the body member sheet 20, the contents 15 contained in the storage space 11 do not pass through the guide portion 52 to the outside. In this embodiment, the cut 52A is provided so as to penetrate only the intermediate layer 20B of the body member sheet 20.

[0034] The steam-passing pouch 10 is heated by a heating means to heat the contents 15. An example of the heating means is a microwave oven. When the steam-passing pouch 10 is heated, water vapor is generated from the contents 15. As the water vapor is generated, the pressure in the storage space 11 increases. The steam-passing section 60 is configured to open as the pressure in the storage space 11 increases, so that the water vapor in the storage space 11 can be discharged to the outside of the steam-passing pouch 10. In a preferred example, the steam-passing section 60 is configured to open when the pressure in the storage space 11 increases to a pressure within a predetermined pressure range.

[0035] The vapor passage portion 60 may take various forms. In one example, the vapor passage portion 60 is provided in at least one of the right side seal portion 33 and the left side seal portion 34. In another example, the vapor passage portion 60 is provided inside the seal portion, independent of the right side seal portion 33 and the left side seal portion 34. FIG. 1 shows an example in which the vapor passage portion 60 is provided only in the right side seal portion 33.

[0036] The shape of the vapor passage portion 60 is recessed from the outside to the inside in the standard width direction. A tip portion 61, which is the innermost portion of the vapor passage portion 60 in the standard width direction, is provided in a location of the body member sheet 20 where strong stress concentration occurs when the pressure in the storage space 11 increases. The tip portion 61 opens when the pressure in the storage space 11 increases to within a predetermined pressure range.

[0037] Specifically, as the pressure in the storage space 11 increases, the front sheet 21 and the back sheet 22 joined at the tip 61 of the steam-passing portion 60 are peeled off, and as shown in FIG. 3, a steam release passage 62 that communicates the storage space 11 with the outside of the steam-passing pouch 10 is formed in the steam-passing portion 60. The range in which the steam-passing portion 60 peels off varies depending on the pressure in the storage space 11. When the pressure in the storage space 11 is high, peeling may progress to the base of the steam-passing portion 60. The passage area of ​​the steam release passage 62 becomes wider as peeling of the steam-passing portion 60 progresses. When the steam-passing portion 60 opens, water vapor in the storage space 11 passes through the steam release passage 62 and is discharged to the outside of the steam-passing pouch 10. By discharging the water vapor, the increase in pressure in the storage space 11 is suppressed, and the steam-passing pouch 10 is prevented from breaking.

[0038] 4 shows the steam-permeable pouch 10 with the opening portion 50 opened after cooking. When opening the opening portion 50, the body member sheet 20 is torn from the tip of the notch 51, and a force is applied to the body member sheet 20 so that the tearing of the body member sheet 20 proceeds along the guide portion 52, and the entire opening portion 50 is opened. A user can use the steam-permeable pouch 10 opened from the opening portion 50 as a container and eat the content 15. EXAMPLES

[0039] Using the samples of the example and comparative example, a test was carried out to confirm the relationship between the layer structure of the body member sheet 20 and the bottom member sheet 23 and the tearability and bottom-openability. The sample was a retort pouch containing curry. After cooking the sample for 1 minute in a 600W microwave oven, the body member sheet 20 was torn and the tearability (hereinafter referred to as "cutability") and bottom-openability were sensorily evaluated using a 5-level scoring system. The results were as follows: "5: good > 4: somewhat good > 3: normal > 2: somewhat poor > 1: poor". Table 1 shows the layer structure of the sample and the scoring results for the cutability and bottom-openability.

[0040] The meanings of the terms related to the materials shown in Table 1 are as follows:

[0041] <Transparent vapor-deposited PET12> A transparent deposition film in which aluminum oxide is deposited on a polyethylene terephthalate film (thickness 12 μm). <Easy-to-cut PET12> A polyethylene terephthalate film (thickness 12μm) with excellent tearability in the MD direction. Excellent tearability in the MD direction means, for example, that the tear force according to the trouser tear method specified in JIS standard K7128-1 is 1.2N or less. <Easy-to-cut CPP60> The low crystalline ethylene elastomer is contained in an amount of 3 to 10 parts by weight per 100 parts by weight of the propylene-ethylene block copolymer, and the low crystalline ethylene elastomer has a density of 0.865 to 0.890 g / cm 3 and the heat absorption amount upon melting as specified in JIS standard 7122 is in the range of 5 to 30 J / g. <Easy to cut Ny15> Polyamide film (thickness 15μm) with excellent tear resistance in the MD direction. <pet12> A polyethylene terephthalate film (thickness 12 μm) with poor tearability in the MD direction. Poor tearability in the MD direction refers to a film with a tear strength of over 1.2 N according to the trouser tear method specified in JIS standard K7128-1. <cpp60> Unstretched polypropylene film (thickness 60μm) with poor tearability in the MD direction. <ny15> Polyamide film (thickness 15μm) with poor tearability in the MD direction.

[0042] [Table 1]

[0043] As can be seen from Table 1, when the sealant layer of the body member sheet is made of an easy-to-cut CPP and the sealant layer of the bottom member is made of CPP, a steam-passing pouch having the best cuttability and bottom-opening suitability is obtained.

[0044] From the above, the steam-passing pouch of the present invention provides the following actions and effects. When the contents are contained in the storage space and the closed steam-passing pouch is heated, a steam vent passage that connects the storage space to the outside is formed in the steam-passing part as the pressure in the storage space increases. Therefore, water vapor in the storage space passes through the steam vent passage and is discharged to the outside of the steam-passing pouch, suppressing an increase in pressure in the storage space.

[0045] In addition, since the sealant layer of the body member sheet is made of a material with excellent tearability in the MD direction, the body member sheet can be easily torn by hand from the opening, making it easy to remove the contents from the opening. In addition, since the sealant layer of the bottom member sheet is made of a material with poor tearability in the MD direction, it is flexible and has bottom-opening properties, making it possible to provide a steam-passing pouch with filling suitability. [Explanation of symbols]

[0046] 10. Steam-permeable pouch 11. Storage space 15...Contents 20... Body component sheet 20A: Outermost layer of body material sheet 20B: Middle layer of body member sheet 20C Body member sheet sealant layer 20D... First adhesive layer of body member sheet 20E... Second adhesive layer of body member sheet 21. Front seat 22. Rear seat 23... Bottom member sheet 23A: Outermost layer of bottom sheet 23B: Bottom member sheet middle layer 23C Bottom member sheet sealant layer 23D: First adhesive layer of bottom member sheet 23E...Second adhesive layer of bottom member sheet 31 Top seal part 32 Bottom seal 33 Right side seal 34 Left side seal 50...Opening part 51 notch 52 Guide section 52A...Cutting 60...Steaming section 61....Tip of steam passage section 62 Steam vent passage

Claims

1. It consists of opposing body sheet members and a bottom sheet member that is folded into the bottom surface. The left side, right side, and bottom edges are sealed, and after filling with contents, the top surface is sealed to create a storage space for the contents. A steam-permeable pouch comprising, at least one of the sealing portions on the left and right sides, a steam-permeable portion for releasing steam from the containment space during heating, and an opening portion on the bottom side of the steam-permeable portion that is substantially parallel to the bottom surface, The body member sheet and the bottom member sheet each include at least an outermost layer, an intermediate layer, and a sealant layer. The outermost layer is made of transparent vapor-deposited polyethylene terephthalate, The intermediate layer of the body member sheet is made of polyethylene terephthalate having a widthwise tear force of 1.2 N or less, in accordance with the trouser tear method specified in JIS K7128-1. The intermediate layer of the body member sheet is composed of a single layer. The opening portion is further provided with a guide portion that guides the cutting of the sheet from the right end of the left side seal portion to the left end of the right side seal portion, and the guide portion includes a cutting line provided only in the intermediate layer of the body member sheet. The sealant layer of the body member sheet is made of a material having a widthwise tear force of 1.2 N or less, in accordance with the trouser tear test specified in JIS K7128-1. The sealant layer of the bottom member sheet is made of unstretched polypropylene. The intermediate layer of the bottom sheet is a breathable pouch made of nylon with a widthwise tear force exceeding 1.2 N, conforming to the trouser tear method specified in JIS K7128-1.

2. The sealant layer of the body sheet contains 3 to 10 parts by weight of low-crystallinity ethylene elastomer per 100 parts by weight of propylene-ethylene block copolymer, wherein the density of the low-crystallinity ethylene elastomer is 0.865 to 0.890 g / cm³. ３ A steam-permeable pouch according to claim 1, made of unstretched polypropylene that falls within the range and whose heat absorption during melting is within the range of 5 to 30 J / g as defined in JIS K7122.

3. The steam-permeable pouch according to claim 1 or 2, wherein the opening portion is provided in a position closer to the steam-permeable portion than the bottom member sheet in the height direction from the top surface to the bottom surface.

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