Packaging bag and method of producing packaging bag

Abstract

To provide a packaging bag allowed to be handled compactly even if it is large in size.SOLUTION: There is provided, according to the present invention, a packaging bag for an electronic oven formed by a flexible film in a bag form. The packaging bag comprises a peripheral surface having a fold portion and a main portion. The fold portion is provided over a predetermined length from an end of the peripheral surface and, in a folded state, fixed on the main portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a packaging bag and a method for manufacturing the packaging bag. [Background technology]

[0002] BACKGROUND ART Packaging bags formed from a film in a bag shape have been known as packaging containers for containing contents such as food.

[0003] Patent Document 1 discloses a package that can hold food ingredients and be cooked in a microwave oven. The package includes a storage section for storing food ingredients, a steaming section for venting steam generated during heating, and a zipper member for opening and closing the package, with a seal formed around the periphery. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2018-122931 Summary of the Invention [Problem to be solved by the invention]

[0005] Such packaging bags may be formed with components having various functions, and may be large depending on the amount of ingredients expected to be added during cooking. However, when displaying packaging bags or storing inventory, it is preferable that the packaging bags be as small as possible in size to save space.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a packaging bag that can be handled compactly even if it is a large packaging bag. [Means for solving the problem]

[0007] According to the present invention, the following inventions are provided. [1] A packaging bag for a microwave oven, made of a flexible film formed into a bag shape, having a peripheral surface portion, the peripheral surface portion having a folding portion and a main body portion, the folding portion being provided over a predetermined length from the end of the peripheral surface portion and being fixed to the main body portion in a folded state. [2] A packaging bag as described in [1], wherein the packaging bag has a bottom surface and can stand on its own with the bottom surface facing downward, the peripheral surface is configured to stand up from the bottom surface, and the folding portion is configured over a predetermined length from the upper end of the peripheral surface and is folded downward. [3] A packaging bag according to [1] or [2], wherein the peripheral portion has an opening that opens upward, the peripheral portion has an opening / closing member configured to be able to open and close the opening, the opening / closing member is provided on the folding portion, the main body portion has a fixed portion that is fixed to the folding portion, the folding portion has a fixed portion that is provided above the opening / closing member, and in the folded state, the fixed portion is fixed to the fixed portion. [4] The packaging bag according to [3], wherein the fixing portion and the fixed portion are crimped together. [5] [3] A packaging bag as described in [3], wherein the fixed portion and the fixed portion have a cut hole, a binding piece, and a through hole formed across the fixed portion and the fixed portion, the cut hole is formed by cutting into an approximately U-shape, and the binding piece has a tongue-like shape due to the cut, the through hole is positioned adjacent to the base of the tongue of the binding piece, and the binding piece is folded toward the through hole and inserted into the through hole. [6] A method for manufacturing a packaging bag according to any one of [1] to [5], comprising a filling step, a sealing step, a folding step, and a fixing step, wherein the packaging bag has an opening formed above the peripheral surface portion, the peripheral surface portion having an opening / closing member configured to be able to open and close the opening, wherein in the filling step, contents are filled through the opening, in the sealing step, the peripheral surface portion above the opening / closing member is welded to seal the opening, in the folding step, the folding portion is folded, and in the fixing step, the folded folding portion and the main body portion are fixed to each other. [7] A method for manufacturing a packaging bag according to [6], wherein the peripheral portion is composed of a front portion and a back portion arranged opposite each other, the opening / closing member has a first engaging portion, a second engaging portion, and a sealing portion extending from the first engaging portion, and in the sealing process, the sealing portion and the back portion are welded together. [Effects of the Invention]

[0008] In the packaging bag according to the present invention, the folding portion of the packaging bag is folded and fixed to the main body portion. In this configuration, even if the packaging bag is large, it can be handled compactly. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic perspective view of a packaging bag 1 in a folded and fixed state according to a first embodiment of the present invention. [Figure 2] 1 is a plan view of a packaging bag 1 according to a first embodiment of the present invention in an unfolded state. [Figure 3] Fig. 3A is a schematic perspective view of the bottom film 10a, and Fig. 3B is a partial schematic perspective view of the packaging bag 1 as seen from the bottom portion 10 side. [Figure 4] 1 is a schematic perspective view of a packaging bag 1 according to a first embodiment of the present invention in an unfolded state. [Figure 5] 5 is a schematic perspective view showing the packaging bag 1 of FIG. 4 with the upper end welded portion 32 cut off. [Figure 6]Fig. 6A is a schematic cross-sectional view of the packaging bag 1 taken along line CC in Fig. 2. Fig. 6B and Fig. 6C are enlarged views of area D in Fig. 6A, with Fig. 6B showing a state in which the opening / closing member 50 is closed and Fig. 6C showing a state in which the opening / closing member 50 is open. [Figure 7] 2 is a schematic enlarged cross-sectional view of a fixing portion 71 and a fixed portion 61 of the packaging bag 1 taken along the line AA in FIG. 1. [Figure 8] 8A, 8B, 8C, 8D, and 8E are schematic diagrams showing a method for manufacturing the packaging bag 1. [Figure 9] 9A, 9B, and 9C are schematic enlarged views of a fixing portion 71 and a fixed portion 61 of a packaging bag 1 according to a second embodiment of the present invention, in a portion corresponding to region B in FIG. [Figure 10] 10A and 10B are schematic enlarged views of a fixing portion 71 and a fixed portion 61 of a packaging bag 1 according to a modified example of the second embodiment of the present invention, in a portion corresponding to region B in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes embodiments of the present invention. The various features shown in the following embodiments can be combined with one another. Furthermore, each feature can be an independent invention. Furthermore, in the following embodiments, elements not specified in the claims are optional and can be omitted. Any number of "0"s (for example, one or two) may be added to the end of numerical values ​​disclosed in the following description. For example, one or two "0"s may be added after "1.4" to make it "1.40" or "1.400."

[0011] In the following description, the front-rear, left-right, top-bottom directions are defined as shown in Figures 1, 2, and 4. Specifically, the front-rear direction is the thickness direction of the gusset of the packaging bag 1 formed by the bottom surface portion 10, and the top-bottom direction is the height direction of the packaging bag 1. The left-right direction is the direction perpendicular to the plane formed by the front-rear, top-bottom, and bottom-top directions.

[0012] 1. First embodiment A packaging bag 1 according to one embodiment of the present invention is a microwave-safe bag made of flexible film formed into a bag shape. Packaging bag 1 is filled with powdered or liquid food and is distributed on the market in a folded and fixed state as shown in FIG. 1. When a user uses it, packaging bag 1 is unfolded from the folded state, ingredients are placed inside, and the packaging bag 1 can be heated and cooked in a microwave oven or the like. In the following description, the packaging bag 1 in the form shown in FIG. 1 will be referred to as a folded and fixed state, and the unfolded form of packaging bag 1 as shown in FIGS. 4 and 5 will be referred to as an unfolded state.

[0013] 1.1 Structure of packaging bag 1 First, the configuration of the packaging bag 1 will be described with reference to Figures 1 to 7. Note that, for ease of explanation, these figures do not show the contents X filled inside the packaging bag 1. As shown in Figures 1 and 4, the packaging bag 1 has a bottom surface portion 10 and a peripheral surface portion 20. The packaging bag 1 is provided with the peripheral surface portion 20 standing up from the bottom surface portion 10, and the packaging bag 1 can stand on its own with the bottom surface portion 10 facing downwards. The peripheral surface portion 20 forms the side surface of the packaging bag 1 and is composed of a front surface portion 21 and a back surface portion 22 arranged opposite each other. The packaging bag 1 is formed by welding the bottom surface portion 10, the front surface portion 21, and the back surface portion 22 to each other. The packaging bag 1 can contain the contents X inside.

[0014] Specifically, the front portion 21 and the back portion 22 are composed of a front film 21a and a back film 22a, respectively. The front portion 21 and the back portion 22 are provided with side edge welded portions 30 formed by welding the front film 21a and the back film 22a to each other at their left and right ends. This forms the peripheral portion 20 that constitutes the side surface of the packaging bag 1.

[0015] 2, the width W1 of the side edge welded portion 30 is 5 to 25 mm, preferably 10 to 20 mm. Specifically, the width W1 is, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 mm, and may be within a range between any two of the values ​​exemplified here. By setting the width W1 within this range, it is possible to ensure space for providing the fixing portion 71 and the fixed portion 61 (described below) at the side edge welded portion 30, and to prevent the left-right size of the packaging bag 1 from becoming unnecessarily large.

[0016] As shown in Fig. 3A, the bottom portion 10 is made of a bottom film 10a bent into a V shape, and a cutout portion R is formed in the bottom film 10a. The front film 21a and the back film 22a are directly welded to each other in the cutout portion R formed in the bottom film 10a. This configuration allows the packaging bag 1 to stand upright more stably.

[0017] 3B, bottom film 10a is inserted between front film 21a and back film 22a in bottom portion 10. Bottom portion 10 has bottom end welded portion 31 formed by welding the edges of bottom film 10a to front film 21a and back film 22a.

[0018] 2, the width W2 of the bottom welded end portion 31 near the center in the left-right direction is 5 to 25 mm, and preferably 10 to 20 mm. Specifically, width W2 is, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 mm, and may be within a range between any two of the values ​​exemplified here. By setting width W2 within this range, it is possible to ensure space for providing a fixed portion 61 (described later) in bottom welded end portion 31.

[0019] The front film 21a, the back film 22a, and the bottom film 10a are preferably laminated films having a base layer and a sealant layer, and more preferably have an adhesive layer and a printed layer between the base layer and the sealant layer. The front film 21a, the back film 22a, and the bottom film may be films having the same structure and physical properties, or films having different structures and physical properties.

[0020] The base material layer is disposed so as to be exposed on the outer surface of the packaging bag 1, and the sealant layer is disposed so as to be exposed on the inner surface of the packaging bag 1. The sealant layers are welded (heat sealed) together to form side end welds 30, bottom end welds 31, and top end welds 32.

[0021] The substrate layer is formed from a material that is excellent in strength and has high impact resistance. Examples of materials that can be used for the substrate layer include polyamide, polyolefin, polyethylene, and polyester. The film that constitutes the substrate layer preferably has linear cut properties in the MD direction (the direction in which the film flows during production). The substrate layer, which is the outermost layer, may contain an antibacterial or antiviral agent (such as silver ions).

[0022] The adhesive layer is a layer for bonding the base layer and the sealant layer together so that they are laminated together. The bonding method may be extrusion lamination using polyethylene or the like as an adhesive layer, or dry lamination using a polyvinyl acetate adhesive, a polyacrylic ester adhesive, a cyanoacrylate adhesive, an ethylene copolymer adhesive, a cellulose adhesive, a polyester adhesive, a polyamide adhesive, an amino resin adhesive, an epoxy adhesive, a polyurethane adhesive, or the like as an adhesive.

[0023] The sealant layer can be formed from a resin with excellent weldability. For example, the sealant layer can be formed from a polyolefin resin, and the film constituting the sealant layer is preferably one that can be linearly cut in the MD direction.

[0024] Next, the configuration of the peripheral surface portion 20 will be described. As shown in FIG. 4, the upper end of the peripheral surface portion 20 is provided with an upper end welded portion 32, which is formed by welding the front portion 21 and the back portion 22 in the left-right direction. As shown in FIG. 2, the width W3 of the upper end welded portion 32 is 5 to 25 mm, preferably 10 to 20 mm. Specifically, the width W3 may be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 mm, or may be within a range between any two of the values ​​exemplified here. By setting the width W3 within this range, it is possible to ensure space for providing a fixing portion 71, described below, in the upper end welded portion 32.

[0025] A tearing portion 40 is formed below the upper end welded portion 32. The tearing portion 40 is a member for opening the packaging bag 1. Specifically, the tearing portion 40 includes a tear initiation portion 41 and a perforation line 42. The upper end welded portion 32 can be separated by tearing in the left-right direction along the perforation line 42 starting from the tear initiation portion 41. As a result, an opening 23 that opens upward is formed in the peripheral surface portion 20, as shown in FIG. 5. The tear initiation portion 41 is formed, for example, by a notch or cut. The perforation line 42 is formed by perforating the front surface portion 21 and the back surface portion 22.

[0026] The peripheral surface portion 20 also includes an opening / closing member 50. The opening / closing member 50 is configured to be able to open and close the opening 23 in the packaging bag 1 when the upper end welded portion 32 is cut off. As shown in Fig. 4, the opening / closing member 50 is attached below the upper end welded portion 32 and to the inner wall of the peripheral surface portion 20 across the left and right direction of the packaging bag 1.

[0027] The specific configuration of the opening / closing member 50 will be described with reference to Figures 6A to 6C. The upper ends of the front surface 21 and the back surface 22 in Figures 6A to 6C are near the cut line 42, and therefore show cross-sectional views in a state where the upper end welded portion 32 has been cut off. The opening / closing member 50 has a first engagement portion 51, a second engagement portion 52, and a sealing portion 53 extending from the first engagement portion 51. The first engagement portion 51 and the second engagement portion 52 are engageable with each other. The first engagement portion 51 and the second engagement portion 52 have hook portions 51a, 52a and base portions 51b, 52b, respectively.

[0028] As shown in Fig. 6B, hook portions 51a and 52a engage with each other to close opening 23, and as shown in Fig. 6C, the user can apply force in the front-to-rear direction to release the engagement and open opening 23. Base portions 51b and 52b are welded to front portion 21 and back portion 22, respectively, in an arrangement that allows first engaging portion 51 and second engaging portion 52 to engage with each other.

[0029] Although the entire surfaces of base portions 51b and 52b may be welded to front portion 21 and back portion 22, respectively, it is preferable that they are welded to the surfaces located above and / or below hook portions 51a and 52a. Specifically, it is preferable that base portion 52b be welded to back portion 22 to the surfaces located above and / or below hook portion 52a.

[0030] On the other hand, it is preferable that the base 51b is welded to the front surface 21 at a surface located above the hook portion 51a. That is, in the base 51b provided on the front surface side where the joining portion 24 (described later) is provided, the side below the hook portion 51a is not welded to the front surface 21, and it is preferable that the base 51b is configured to be easy-peelable. In other words, the area from the lower end of the base 51b to the upper end of the hook portion 51a is not welded. With this configuration, when the packaging bag 1 is heated and the internal pressure increases and the opening / closing member 50 expands, a force in the direction of opening the opening / closing member 50 is less likely to be applied to the opening / closing member 50, and leakage of the contents X or steam from the opening / closing member 50 can be suppressed.

[0031] Furthermore, the length L1 from the lower end of the tearing portion 40 to the upper end of the hook portion 51a is, for example, 3 to 20 mm. The length L1 is preferably 5 to 15 mm. Specifically, the length L1 is, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 mm, and may be within a range between any two of the numerical values ​​exemplified here. By setting the length L1 within this range, the user can hook their fingers over the upper end of the packaging bag 1 and easily open the opening / closing member 50.

[0032] The sealing portion 53 extends from the base 51b of the first engagement portion 51 and is welded to the back surface portion 22 (hereinafter, the portion where the sealing portion 53 and the back surface portion 22 are welded is referred to as the internal weld portion 33). As a result, the internal space of the packaging bag 1 below the opening / closing member 50 is sealed. The packaging bag 1 is distributed on the market filled with food, but the provision of the internal weld portion 33 makes it possible to prevent the first engagement portion 51 and the second engagement portion 52 from becoming soiled when the user uses the bag. Furthermore, the internal weld portion 33 is preferably easy to peel, since the user must remove the weld when using the bag.

[0033] Sealing portion 53 may have any configuration as long as it can separate the internal space of packaging bag 1 from first engaging portion 51 and second engaging portion 52. For example, a sealing portion (not shown) may be further provided in second engaging portion 52, and the sealing portions may be configured to be welded together.

[0034] 2 and 6A, the front surface 21 of the packaging bag 1 is provided with a seam 24 (illustration of the seam 24 is omitted in the other figures for the sake of convenience). The front surface 21 has an upper front surface 21b and a lower front surface 21c, and the seam 24 is formed by overlapping the upper front surface 21b and the lower front surface 21c. As shown in FIG. 6A, the fold F is preferably positioned at the base of the seam 24.

[0035] Furthermore, a steam release section (not shown) is formed in the gable section 24 to release steam generated from inside the packaging bag 1 when cooking in a microwave oven using the packaging bag 1. Any existing configuration can be used for the steam release section. Because the packaging bag 1 is cooked with the bottom section 10 facing downwards, it is preferable that the steam release section be formed above the peripheral section 20, but a preferable arrangement can be achieved by providing the steam release section in the gable section 24.

[0036] Next, the folding configuration of packaging bag 1 will be described with reference to Figures 1, 2, and 4. Peripheral surface portion 20 includes folding portion 70 and main body portion 60. Folding portion 70 is provided over a predetermined length from the end of peripheral surface portion 20. Folding portion 70 can be folded along crease F, and is fixed to main body portion 60 in the folded state.

[0037] In the example of Fig. 4, the folding portion 70 is provided over a predetermined length from the upper end of the peripheral portion 20, and therefore the upper end welded portion 32, the tearing portion 40, and the opening / closing member 50 are provided in the folding portion 70. At the fold F, the peripheral portion 20 is creased to facilitate mountain folding toward the rear. The folding portion 70 is also folded downward and fixed to the main body portion 60 (Fig. 1).

[0038] 2, the predetermined length of the folding portion 70, i.e., the length L2 in the vertical direction, is 10 to 60% of the length L3 of the entire packaging bag 1 in the vertical direction, and preferably 30 to 40%. Specifically, the length L2 is, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60% of the length L3, and may be within a range between any two of the values ​​exemplified here. By setting the length L2 in this manner, the packaging bag 1 can be handled compactly while ensuring the volume of the contents X filled in the packaging bag 1.

[0039] Next, a specific fixing configuration of the main body portion 60 and the folding portion 70 will be described. The main body portion 60 has a fixed portion 61, and the folding portion 70 has a fixing portion 71. In the packaging bag 1, the fixed portion 61 and the fixing portion 71 are fixed to each other. The fixed portion 61 is a portion that is fixed to the folding portion 70 when the folding portion 70 is folded and comes into contact with the fixing portion 71. Therefore, the same number of fixing portions 71 and fixed portions 61 are provided.

[0040] For example, the fixing portion 71 is preferably provided at the side edge welded portion 30. Therefore, in this case, the fixed portion 61 is also provided at the side edge welded portion 30. The steps of the manufacturing method for the packaging bag 1 will be described later, but since the fixing portion 71 and the fixed portion 61 are fixed to each other with the packaging bag 1 filled with the contents X, if the fixing portion 71 is provided in the center in the left-right direction of the packaging bag 1, for example, the presence of the contents X may make it difficult to fix the fixing portion 71, or even if the fixing portion 71 can be fixed, there is a risk that the packaging bag 1 may be damaged when the user unfolds the bag, causing the contents X to spill out. Therefore, it is preferable to provide the fixing portion 71 in the above position.

[0041] More preferably, the fixing portion 71 is preferably provided above the opening / closing member 50. That is, the fixing portion 71 is preferably provided at an upper corner of the unfolded packaging bag 1, as shown in the example shown. For example, even if the packaging bag 1 is damaged when the user releases the fixation between the folding portion 70 and the main body portion 60, the portion above the opening / closing member 50 is torn and separated from the packaging bag 1 from the tearing portion 40, so the damaged area can be reduced.

[0042] For example, if the fixing portion 71 is provided below the opening / closing member 50, the opening / closing member 50 to the upper end welded portion 32 will not be fixed to the main body 60 in the folded and fixed state, and these parts may get caught and become unfixed during distribution. Therefore, it is preferable to provide the fixing portion 71 at the above position.

[0043] Furthermore, when the vertical length L2 of the folding portion 70 is approximately half the vertical length L3 of the entire packaging bag 1, the fixing portion 71 may be provided at the upper end welded portion 32, and the fixed portion 61 may be provided at the lower end welded portion 31. In this case, no matter where the fixing portion 71 is provided in the left-right direction of the packaging bag 1, there is no risk of it affecting the inside of the packaging bag 1.

[0044] In the illustrated example, the fixed portion 71 is provided at two locations, the upper right corner and the upper left corner, but the fixed portion 71 may be provided at only one location, or at three or more locations.

[0045] Next, the fastening configuration of the fixing portion 71 and the fixed portion 61 will be described with reference to Fig. 7. The fixing portion 71 and the fixed portion 61 can maintain the folded and fixed state during distribution or when displayed in stores, and are fastened with a force that allows the user to easily return them to the unfolded state without using tools when using them. Therefore, even if the packaging bag 1 is large, the folded foldable portion 70 will not open, and it can be handled compactly.

[0046] In the first embodiment, the fixing portion 71 and the fixed portion 61 are fixed by being crimped. As shown in Fig. 7, in the first embodiment, the fixing portion 71 and the fixed portion 61 can be fixed by engaging them together in a zigzag pattern. In the zigzag pattern, there are at least two fixing units U formed by one peak and one valley, and preferably three or more. In the illustrated example, four fixing units U are provided.

[0047] The cross-sectional shape that realizes the engagement between the fixing portion 71 and the fixed portion 61 need not be a zigzag shape, but may be, for example, a sine wave shape or a rectangular wave shape.

[0048] 1.2 Manufacturing method of packaging bag 1 Here, a method for manufacturing the packaging bag 1 will be described mainly with reference to Fig. 8. The method for manufacturing the packaging bag 1 includes a bag-making step, a filling step, a sealing step, a folding step, and a fixing step, in this order.

[0049] (1) Bag making process In the bag-making process, a flexible film is formed into a bag shape (FIG. 8A). Specifically, the bottom film 10a is inserted between the front film 21a and the back film 22a, on which the seam 24 has been formed, and they are welded together to form the bottom welded portion 31. In addition, the opening / closing member 50 is attached to the front film 21a and the back film 22a across the left and right direction of the packaging bag 1. The bases 51b and 52b of the first engaging portion 51 and the second engaging portion 52 are welded to the upper inside surfaces of the front portion 21 and the back portion 22, respectively, so that the hook portions 51a and 52a engage with each other (see FIG. 6). At this time, the first engaging portion 51 is attached to the front portion 21 so that the sealing portion 53 is located on the bottom side.

[0050] Next, the side edges of the front film 21a and the back film 22a are welded to form side edge welded portion 30. Next, the bag-shaped film is formed with opening portion 40. In the bag-making process, the bag may be made by any existing method and procedure as long as it can produce a bag as shown in FIG.

[0051] (2) Filling process In the filling step, as shown in Fig. 8B, the packaging bag 1 is opened and the contents X are filled through the opening 23. The packaging bag 1 is set in the filling machine with the bottom portion 10 facing downward, and the contents X are filled from above the packaging bag 1 as shown by the arrow in Fig. 8B. When the filling step is performed, the packaging bag 1 does not have the upper end welded portion 32 and the inner welded portion 33 formed thereon, so the contents X can be filled through the opening 23.

[0052] In the packaging bag 1 according to the first embodiment, a bottom surface portion 10 is formed to allow the bag to stand on its own, making it difficult to fill the contents X from the bottom surface portion 10 side. Furthermore, when attempting to fill from either the left or right end of the peripheral surface portion 20, depending on the size of the packaging bag 1, the opening for filling may become narrow, making filling difficult. Furthermore, when filling from either the left or right end, a separate opening for filling may need to be formed, increasing the number of bag-making processes. In the packaging bag 1 according to the present embodiment, the contents X are filled from the opening 23 used by the user to insert ingredients, so the opening for filling is large enough, and there is no need to provide a separate opening. Therefore, the contents X can be easily filled into the packaging bag 1.

[0053] (3) Sealing process In the sealing process, the peripheral surface portion 20 above the opening / closing member 50 is welded to form an upper end welded portion 32 so as to seal the opening 23 (FIG. 8C). Also, in the sealing process, the sealing portion 53 and the back surface portion 22 are welded to each other so as to be easy to peel, to form an inner welded portion 33 (FIG. 6B).

[0054] (4) Folding process In the folding step, the peripheral portion 20 is folded to form fold lines F, thereby forming the folded portion 70 and the main body portion 60 (FIG. 8D). Next, in the folding step, the folded portion 70 is folded along the fold lines F. The fold lines may be formed in the bag-making step.

[0055] (5) Fixing process In the fixing step, the folded folding portion 70 and the main body portion 60 are fixed together to bring the packaging bag 1 into a folded and fixed state (FIG. 8E). Specifically, in the fixing step, the fixing portion 71 and the fixed portion 61 are clamped and pressurized using a pair of dies that can be embossed into a sawtooth shape, thereby crimping the fixing portion 71 and the fixed portion 61 together. In the fixing step, when applying pressure, the temperature may be controlled, for example, by heating for a short period of time, to adjust the crimping force.

[0056] 1.3 How to use packaging bag 1 The method by which a user uses the packaging bag 1 will be described below. First, the packaging bag 1 is unfolded from its folded and fixed state. Next, the opening 23 is exposed by tearing the periphery of the upper end welded portion 32 from the opening portion 40. The user inserts a finger or the like into the opening 23 to open the opening / closing member 50, and then releases the welding of the inner welded portion 33 to separate the sealed portion 53 from the back portion 22. Next, the user places any food item into the internal space through the opening 23, closes the opening / closing member 50 again, and can heat and cook the food using a microwave oven or the like.

[0057] 2. Second embodiment A second embodiment of the present invention will be described with reference to Figure 9. This embodiment is similar to the first embodiment, and the details described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs from the first embodiment in the fixing configuration between the fixing portion 71 and the fixed portion 61. Therefore, the fixing step in the manufacturing method of the packaging bag 1 also differs from the first embodiment. The following description will focus on the differences.

[0058] 2.1 Structure of packaging bag 1 The fixing part 71 and the fixed part 61 in the second embodiment are fixed as shown in Fig. 9C. Note that Figs. 9A to 9C are enlarged views of the fixing part 71 and the fixed part 61 in a portion corresponding to region B in Fig. 1, and show the state when viewed from the same direction as the packaging bag 1 shown in Fig. 1.

[0059] The fixing portion 71 and the fixed portion 61 have a cutout hole 80, a binding piece 81, and a through hole 82 formed across them. The cutout hole 80 is formed by cutting into a substantially U-shape, and a tongue-shaped binding piece 81 is formed by the cutout. The through hole 82 is located adjacent to the base of the tongue of the binding piece 81. The binding piece 81 is folded toward the through hole 82 and inserted into the through hole 82. With this configuration, the fixing portion 71 and the fixed portion 61 are fixed together.

[0060] Furthermore, although the binding piece 81 may be folded toward either the front or rear of the packaging bag 1, it is preferable that it be folded toward the rear of the packaging bag 1 in the same direction as the folding portion 70 is folded (FIGS. 9B and 9C). In other words, it is preferable that it be bent toward the folding portion side in the folded and fixed state of the packaging bag 1. With this configuration, the folded and fixed state can be released more easily.

[0061] In the illustrated example, the through-hole 82 is formed by cutting a substantially H-shape, but is not limited to this shape. The through-hole 82 can be formed in any shape as long as the binding piece 81 can be inserted therethrough, and may be cut out in, for example, a circular, oval, or rectangular shape.

[0062] 10A, the through-hole 82 may be disposed above the cut-out hole 80. The cut-out hole 80 and the through-hole 82 may be formed so as to be adjacent to each other in the left-right direction.

[0063] The shape of the slit 80 does not have to be a substantially U-shape as long as it is possible to form a binding piece 81 of a size that can be folded. For example, the binding piece 81 may be configured so that the widths of the base and tip are different. Also, for example, it may be configured so that a protrusion is provided in a substantially U-shape. As an example of such a configuration, as shown in FIG. 10B, it may be configured so that a protrusion is provided in the shape of an arrow. By using such a configuration, it is possible to make it difficult for the folding portion 70 and the main body portion 60 to come apart.

[0064] In the second embodiment as well, the fixing portion 71 is preferably formed at the upper corner. Since the folding portion 70 and the main body portion 60 in the second embodiment have the cut hole 80 and the through hole 82 formed therein, for example, when the fixing portion 71 is provided below the opening / closing member 50 and closer to the center than the side edge welded portion 30 when the packaging bag 1 is in an unfolded state, holes that connect the inside where the contents X are stored to the outside of the packaging bag 1 are formed in the fixing portion 71 and the fixed portion 61, respectively.

[0065] As a result, when a user cooks, there is a risk that the content X may leak out through the hole, or that steam generated during heating may exert pressure on the hole, damaging the packaging bag 1. Therefore, it is preferable that the fixing portion 71 be formed at the upper corner.

[0066] Moreover, it is preferable that the fixed portion 71 is formed at least on the side edge welded portion 30. With this configuration, even if there is no space to provide the fixed portion 71 at a position above the opening / closing member 50, for example, the contents X will not leak out through the hole and the packaging bag 1 will not be damaged.

[0067] 2.2 Manufacturing method of packaging bag 1 In the fixing step in the second embodiment, first, as shown in Fig. 9A, a predetermined blade is used to form a cut hole 80 and a through hole 82 across the fixing portion 71 and the fixed portion 61. Next, as shown in Fig. 9B, the binding piece 81 is folded and the tip of the binding piece 81 is inserted into the through hole 82. This fixes the folding portion 70 and the main body portion 60 together.

[0068] 3. Third embodiment This embodiment is similar to the first embodiment, and the details described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs from the first embodiment in the fixing configuration between the fixing portion 71 and the fixed portion 61. Therefore, the manufacturing method of the packaging bag 1 also differs from the first embodiment. The following description will focus on the differences.

[0069] In the third embodiment, the fixing portion 71 and the fixed portion 61 are fixed to each other via an adhesive. Any material can be used as the adhesive as long as it has sufficient adhesive strength to prevent damage to the packaging bag 1 when the user changes the packaging bag 1 from the folded and fixed state to the unfolded state and to allow the folding portion 70 to be pulled away from the main body portion 60 with a small force. Double-sided tape may be used instead of adhesive.

[0070] In the method for manufacturing the packaging bag 1 according to this embodiment, the folding step and the fixing step are carried out simultaneously (hereinafter referred to as the folding and fixing step). The method for manufacturing the packaging bag 1 according to this embodiment also includes an adhesive application step. In the adhesive application step, adhesive is applied to either the fixing portion 71 or the fixed portion 61. The adhesive application step is preferably carried out after the sealing step and before the folding and fixing step. In this case, since the upper end welded portion 32 is formed in the sealing step, the fixing portion 71 can be provided at the upper end welded portion 32.

[0071] However, the folding and fixing step may be performed before the sealing step. In this case, other steps are performed in the adhesive application step before the folding and fixing step. Therefore, in the adhesive application step, for example, after applying adhesive to the fixed portion 61, it is preferable to attach a covering member so that other members do not adhere to the adhesive.

[0072] In this embodiment, adhesive is applied at the start of the folding and fixing step. Therefore, in the fold fixing step, folding portion 70 is fixed to main body portion 60 by folding folding portion 70 at fold F. Note that if a covering member is applied in the adhesive application step, the covering member is removed before the folding operation is performed.

[0073] 4. Fourth embodiment This embodiment is similar to the first embodiment, and the details described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs from the first embodiment in the fixing configuration between the fixing portion 71 and the fixed portion 61. Therefore, the fixing step in the manufacturing method of the packaging bag 1 also differs from the first embodiment. The following description will focus on the differences.

[0074] The packaging bag 1 according to this embodiment includes a fixing member, and the fixing portion 71 and the fixed portion 61 are fixed by the fixing member. The fixing member is, for example, a clip. The fixing member may have any configuration as long as it has a shape that can clamp the fixing portion 71 and the fixed portion 61 together.

[0075] In the fixing step, a fixing member is attached so as to sandwich the fixing portion 71 and the fixed portion 61 together, thereby fixing the folding portion 70 and the main body portion 60 together.

[0076] 5. Other Embodiments The present invention can also be implemented in the following aspects. In the above embodiment, the self-standing packaging bag 1 provided with the bottom surface portion 10 has been described, but the packaging bag 1 may be configured without the bottom surface portion 10. When the packaging bag 1 has fixing portions 71 provided at a plurality of locations, the fixing portions 71 may be fixed with different fixing configurations at each location. In other words, the packaging bag 1 may combine the fixing configurations according to the first to fourth embodiments. The packaging bag 1 may further include a second opening portion that allows the main body portion 60 to be separated into upper and lower halves. For example, the second opening portion may be provided at the same position as the fold F. In this case, the opening / closing member 50 and the steam release portion are separated from the packaging bag 1, which increases convenience when a user uses the packaging bag 1 as tableware after cooking with the packaging bag 1. In the fixing configuration according to the second embodiment, it is not necessary to form the through-holes 82. Specifically, the folding portion 70 and the main body portion 60 may be fixed together only by folding the binding pieces 81. [Explanation of symbols]

[0077] 1: Packaging bag 10: Bottom part 10a: Bottom film 20: Peripheral part 21: Front part 21a: Front film 21b: Upper front 21c: lower front 22: Back part 22a: Rear film 23: Opening 24: Gassho part 30: Side end welding part 31: Lower end welding part 32: Upper end welding part 33: Internal welding part 40: Opening section 41:Start part 42:Cutting line 50: Opening and closing member 51: First engagement portion 51a: Hook part 51b: Base 52: Second engagement portion 52a: Hook part 52b: base 53: Sealing part 60: Main body 61: Fixed part 70: Folding section 71:Fixed part 80: Slotted hole 81: Binding piece 82: Through hole F: Fold R: Notch U: Fixed unit X: Contents

Claims

1. A packaging bag for a microwave oven, in which a flexible film is formed into a bag shape, a peripheral portion; the peripheral portion includes a folding portion and a main body portion; The folding portion is provided over a predetermined length from an end of the peripheral portion, and is fixed to the main body portion in a folded state.

2. The packaging bag according to claim 1, The packaging bag has a bottom surface and can stand on its own with the bottom surface facing downwards, The peripheral surface portion is provided so as to rise from the bottom surface portion, The folding portion is provided over a predetermined length from the upper end of the peripheral portion and is folded downward.

3. The packaging bag according to claim 2, An opening that opens upward is formed in the peripheral surface portion, the peripheral surface portion includes an opening / closing member configured to open and close the opening, The opening / closing member is provided on the folding portion, the main body portion includes a fixed portion that is fixed to the folding portion, The folding portion includes a fixing portion provided above the opening / closing member, and in the folded state, the fixing portion is fixed to the fixed portion.

4. The packaging bag according to claim 3, The packaging bag, wherein the fixing portion and the fixed portion are crimped together.

5. The packaging bag according to claim 3, The fixing portion and the fixed portion have a cut hole, a binding piece, and a through hole formed across the fixing portion and the fixed portion, The cut hole is formed by cutting into a substantially U-shape, and the tongue-shaped binding piece is formed by the cut. The through-hole is disposed adjacent to the base side of the binding piece, The binding piece is folded toward the through hole and inserted into the through hole.

6. A method for manufacturing a packaging bag according to any one of claims 1 to 5, The method includes a filling step, a sealing step, a folding step, and a fixing step, The packaging bag has an opening formed above the peripheral surface portion, the peripheral surface portion includes an opening / closing member configured to open and close the opening, In the filling step, a content is filled through the opening, In the sealing step, the peripheral surface portion above the opening / closing member is welded to seal the opening, In the folding step, the folding portion is folded, In the fixing step, the folded portion and the main body portion are fixed together.

7. A method for manufacturing the packaging bag according to claim 6, The peripheral surface portion is composed of a front surface portion and a rear surface portion arranged opposite to each other, the opening / closing member includes a first engaging portion, a second engaging portion, and a sealing portion extending from the first engaging portion; In the sealing step, the sealing portion and the back portion are welded together.

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