Food packaging bag and its manufacturing method

Abstract

To provide a food packaging bag that can suppress used amount of resin and its manufacturing method.SOLUTION: It includes a sheet-shaped first packaging material 10, a sheet-shaped second packaging material 20 that is attached to the first packaging material 10 and forms an accommodating portion 33 that accommodates a sandwich 100 in between the first packaging material 10, and an opening 34 that opens the accommodating portion 33 to the outside, at least the first packaging material 10 out of the first packaging material 10 and the second packaging material 20 has, on at least part of it, a window portion 14 made of a visible paper material through which the sandwich 100 accommodated in the accommodating portion 33 can be visually recognized from outside.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] Conventionally, foods such as sandwiches, cooked bread, castella cakes, sweet breads, etc. have been packaged in packaging bags and sold at convenience stores, supermarkets, etc. For example, in the case of a right-angled triangular sandwich consisting of a slice of bread with ingredients between it, a packaging bag type is known in which a pair of resin films are overlapped to form a bag body sealed on three sides, and the sandwich is inserted and packaged inside (see Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-171326 A Summary of the Invention [Problem to be solved by the invention]

[0004] This type of packaging bag is generally made of a resin film such as polyethylene, as described in the above Patent Document 1. However, in recent years, there has been concern about environmental pollution caused by waste resin products, so-called plastic waste, and this problem is also affecting food packaging bags.

[0005] Therefore, an object of the present invention is to provide a food packaging bag that can reduce the amount of resin used, and a method for manufacturing the same. [Means for solving the problem]

[0006] (1) The food packaging bag of the present invention comprises a first sheet-like packaging material, a second sheet-like packaging material attached to the first packaging material and forming a storage section between the first packaging material and the second packaging material for storing food, and an opening for opening the storage section to the outside, and at least the first packaging material of the first and second packaging materials has a window section in at least a part of it made of a visible paper material that allows the food stored in the storage section to be viewed from the outside.

[0007] (2) In (1), it is preferable that the first packaging material is entirely made of a paper material, including the window portion, and that the portion other than the window portion is made of a paper material that is less visible than the paper material of the window portion.

[0008] (3) In the configuration (1) or (2), it is preferable that the second packaging material has a folded-in portion that closes the opening, and at least the folded-in portion is made of a resin film.

[0009] (4) In the above (1) or (2), it is preferable that both the first packaging material and the second packaging material are made of paper.

[0010] (5) In any one of (1) to (4), it is preferable that the food contained in the container is a sandwich having a substantially triangular shape, and the window is disposed in a position facing the ingredients of the sandwich.

[0011] (6) A method for producing a food packaging bag of the present invention is a method for producing a food packaging bag as described in any one of (1) to (5), comprising the steps of: unwinding a first roll from which a plurality of the first packaging materials can be formed, and transporting a second roll from which a plurality of the second packaging materials can be formed in a predetermined transport direction, while overlapping the first roll and the second roll; sealing the overlapped first roll and the second roll to each other while leaving the opening on one side in the transport direction to form a sealed portion, thereby forming the food packaging bags so as to be continuously arranged in the transport direction; and cutting the plurality of the sealed portions in the transport direction to obtain a plurality of the food packaging bags in sequence.

[0012] (7) In (6), it is preferable that the food packaging bag has an approximately trapezoidal shape and has the opening at one end in the height direction, and that the openings are arranged alternately on both sides of the conveying direction in the food packaging bags adjacent to each other in the conveying direction. Effect of the Invention

[0013] According to the present invention, it is possible to provide a food packaging bag that can reduce the amount of resin used, and a method for manufacturing the same. [Brief description of the drawings]

[0014] [Figure 1] 1 is a perspective view showing a food packaging bag according to a first embodiment and a sandwich packaged in the packaging bag; [Diagram 2] FIG. 1 is an exploded perspective view of a food packaging bag according to a first embodiment. [Diagram 3] FIG. 1 is a plan view of a food packaging bag according to a first embodiment, as viewed from the front side, that is, the first packaging material side. [Figure 4] FIG. 2 is a plan view of the food packaging bag according to the first embodiment, seen from the back side, the second packaging material side. [Diagram 5] FIG. 5 is a cross-sectional view of FIG. 4 . [Figure 6]1A to 1D are perspective views showing the steps of packaging a sandwich in the food packaging bag according to the first embodiment in the order of (a) to (d). [Figure 7] 1 is a perspective view showing a sandwich packaged in the food packaging bag according to the first embodiment. FIG. [Figure 8] 1 is a perspective view showing a schematic diagram of a production line for carrying out a method for producing food packaging bags according to a first embodiment. [Figure 9] FIG. 2 is a perspective view showing a schematic diagram of a method for producing a first web in the method for producing a food packaging bag according to the first embodiment. [Figure 10] 9 is an enlarged plan view showing a step D, a step E and a step F in the production line shown in FIG. 8. [Figure 11] FIG. 5 is an exploded perspective view of a food packaging bag according to a second embodiment. [Figure 12] FIG. 6 is a plan view of a food packaging bag according to a second embodiment, as viewed from the first packaging material side on the front side. [Figure 13] FIG. 11 is a plan view of the food packaging bag according to the second embodiment, seen from the back side, the second packaging material side. [Figure 14] 14 is a cross-sectional view taken along the line XIV-XIV of FIG. 13. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment will be described with reference to the drawings. (First embodiment) 1 shows a food packaging bag (hereinafter, abbreviated as packaging bag) 1 according to a first embodiment, and a right-angled triangular sandwich 100 contained in the packaging bag 1. That is, the packaging bag 1 of the first embodiment is a bag for packaging the right-angled triangular sandwich 100. The sandwich 100 has a plurality of right-angled triangular slices of bread 101 and ingredients 102 sandwiched between two slices of bread 101. The sandwich 100 is inserted into the packaging bag 1 from one of its apexes 105 other than the right angle, and is packaged by the packaging bag 1.

[0016] 2 to 5, the packaging bag 1 includes a sheet-like first packaging material 10 constituting the front side, and a sheet-like second packaging material 20 constituting the back side. Fig. 2 is an exploded perspective view of the packaging bag 1, Fig. 3 is a plan view of the packaging bag 1 seen from the first packaging material 10 side (front side), Fig. 4 is a back view of the packaging bag 1 seen from the second packaging material 20 side (back side), and Fig. 5 is a VV cross-sectional view of Fig. 4.

[0017] As shown in Figures 2 to 4, the first packaging material 10 and the second packaging material 20 each have a vertically long, symmetrical trapezoidal shape that is roughly an isosceles triangle shape, and have the same shape and dimensions as each other. The packaging bag 1 is formed by overlapping the first packaging material 10 and the second packaging material 20 with the same shape, and bonding the sealed portions 30 on three sides together to form a bag. As shown in Figures 3 and 4, the sealed portions 30 on three sides include two tiers of top sealed portions 31, one above the other, provided at one end side of the length direction L of the packaging bag 1 (the upper side in Figures 3 and 4), and side sealed portions 32 on both sides in the width direction W. Each of the top sealed portions 31 is connected to the side sealed portions 32.

[0018] As shown in Fig. 1, a storage section 33 for storing a sandwich 100 is formed between a first packaging material 10 and a second packaging material 20. Parts of the outer peripheral edge of the packaging bag 1 other than the sealed portion 30 are spaced apart from each other to form an opening 34 that opens the storage section 33 to the outside. The opening 34 is provided on the other end side in the length direction (the lower side in Figs. 3 and 4) and on the side of a bottom 7 described below. The sandwich 100 is inserted into the storage section 33 from the opening 34.

[0019] As shown in Fig. 3, the packaging bag 1 has a top portion 5 at one end in the length direction, a bag body portion 6 including a storage portion 33, and a bottom portion 7 at the other end in the length direction. In Figs. 3 and 4, a two-dot chain line G indicates a rough boundary between the top portion 5 and the bag body portion 6, and a two-dot chain line H indicates a rough boundary between the center portion 26 and the bottom portion 27. Notches 7a are formed at both corners of the bottom portion 7. An opening 34 is disposed on the bottom portion 7 side.

[0020] As shown in Figs. 2 and 3, the first packaging material 10 is a single sheet formed by integrating three divided sheets arranged in the length direction L, namely, a top sheet 11, a center sheet 12, and a bottom sheet 13. The top sheet 11 constitutes the bag body 6 and a part of the top 5 of the packaging bag 1. The center sheet 12 constitutes the bag body 6 of the packaging bag 1. The bottom sheet 13 constitutes the bag body 6 and a part of the bottom 7 of the packaging bag 1. The top sheet 11 and the center sheet 12 each have a trapezoidal shape that gradually becomes wider from one end side to the other end side in the length direction L. The bottom sheet 13 has a hexagonal shape that first becomes wider and then becomes narrower from one end side to the other end side in the length direction L. The bottom sheet 13 has a first packaging material side cutout 10a that corresponds to the cutout 7a of the packaging bag 1. Bottom sheet 13 includes a fold-in portion 13b that is folded to close opening 34 when the contained sandwich 100 is packaged.

[0021] The top sheet 11, the center sheet 12, and the bottom sheet 13 are all made of flexible paper material. The center sheet 12 is made of a visible paper material that allows the sandwich 100 contained in the container 33 to be seen from the outside. The packaging bag 1 of the embodiment has a window 14 formed by the center sheet 12. In this specification, the term "paper material" refers to unprocessed paper alone, processed paper alone, and such paper coated with a resin film or the like on at least one side.

[0022] As the paper material of the central sheet 12 constituting the window portion 14, a translucent paper material such as glassine paper or cellophane paper is preferably used. In addition, such a paper material may be laminated with a resin film such as biaxially oriented polypropylene (OPP) on at least the inner surface facing the storage portion 33, thereby providing a certain degree of water resistance.

[0023] On the other hand, the paper material of the top sheet 11 and the bottom sheet 13 sandwiching the central sheet 12 may be the same as that of the central sheet 12, but may be made of a paper material with lower visibility than that of the central sheet 12. That is, the sandwich 100 may not be visible from the outside through the top sheet 11 and the bottom sheet 13. This is because the sandwich 100 can be visible from the outside through the central sheet 12 of the window portion 14. Examples of such paper materials include Western paper, Japanese paper, synthetic paper, and craft paper. The paper material constituting the top sheet 11 and the bottom sheet 13 may be a paper material with a certain degree of water resistance, in which at least the inner surface facing the storage section 33 is laminated with a resin film such as OPP (biaxially oriented polypropylene), like the central sheet 12. The top sheet 11 and the bottom sheet 13 may be made of the same type of paper material or different types of paper materials.

[0024] As shown in Figure 5, the ends of the top sheet 11 and bottom sheet 13 are overlapped and joined to the outside of the central sheet 12. In this case, the sheets 11, 12, and 13 are joined with an adhesive that is suitable for each of them. Alternatively, in the case of a paper material that is laminated with a film as described above, the top sheet 11 and bottom sheet 13 can be joined to the central sheet 12 by heat sealing using the film. Since paper materials are joined together, shrinkage at the joints is unlikely to occur.

[0025] As shown in Figs. 2 and 4, the second packaging material 20 is composed of a single resin film. The second packaging material 20 made of a film may be transparent, translucent or opaque. The second packaging material 20 has a top 25, a center 26 and a bottom 27 corresponding to the top 5, the bag body 6 and the bottom 7 of the packaging bag 1, respectively. The bottom 27 includes a folded-in portion 27b that is folded in so as to close the opening 34 when packaging the sandwich 100 contained therein. The bottom 27 is formed with a second packaging material-side cutout portion 20a that corresponds to the cutout portion 7a of the packaging bag 1.

[0026] The second packaging material 20 is composed of a single transparent or translucent film made of flexible synthetic resin. The film constituting the second packaging material 20 is preferably heat-weldable to facilitate heat sealing. As such a synthetic resin film, a single-layer or multi-layer synthetic resin film is used. In the case of a single layer, for example, synthetic resin films such as polyvinylidene chloride (PVDC), polyvinylidene chloride (PP), polyethylene terephthalate (PET), etc. are used. In the case of a multi-layer, for example, a synthetic resin film having a three-layer structure in which PVDC (polyvinylidene chloride), which acts as a barrier layer to block moisture, is sandwiched between polyethylene, etc. is preferably used.

[0027] An inverted U-shaped notch 21 is provided in the widthwise center of the top 25 of the second packaging material 20 to provide a tear strip 22 that allows the second packaging material 20 to be partially turned up. A strip-shaped cut tape 23 is attached to the inner surface of the second packaging material 20, extending in the length direction L from the tear strip 22 substantially vertically across the center 26. The cut tape 23 is a synthetic resin film. The second packaging material 20 can be divided into left and right halves by holding the tear strip 22 with fingers and tearing the cut tape 23 from the top 25 side toward the bottom 27 side. This allows the sandwich 100 contained therein to be taken out from the back side, which is the second packaging material 20 side.

[0028] The sandwich 100 is packaged in the packaging bag 1 of the first embodiment as follows. First, as shown in Fig. 1, the opening 34 is opened, and the sandwich 100 is inserted into the storage section 33 from one of the vertices 105 other than the right angle. At this time, the second packaging material 20 on the back side is placed on the bottom and the first packaging material 10 on the front side is placed on the top, and the sandwich 100 is inserted into the packaging bag 1 with the inclined surface 106 of the sandwich 100, which corresponds to the hypotenuse of a right triangle, facing the first packaging material 10.

[0029] Next, as shown in Fig. 6(a), apex 105 on the insertion tip side of sandwich 100 reaches the inside of apex 5 on the rear side, so that sandwich 100 is contained in packaging bag 1. In this contained state, packaging bag 1 deforms into a right-angled triangular shape that conforms to the shape of sandwich 100, and opening 34 opens into a rectangular shape. An excess portion is generated on the opening 34 side of containing section 33 of sandwich 100, and this excess portion becomes square tubular sealing portion 35 that seals the packaged state. Sealing portion 35 includes folded-in portion 13b of bottom sheet 13 of first packaging material 10 and folded-in portion 27b of bottom 27 of second packaging material 20.

[0030] Next, as shown in FIG. 6(b), the widthwise center portion 27c of the bottom portion 27 of the second packaging material 20 constituting the sealing portion 35 is folded toward the first packaging material 10 so as to contact the rectangular surface of the sandwich 100 exposed through the opening 34. Next, the side portions 35a on both sides where the folded-in portion 13b of the first packaging material 10 constituting the sealing portion 35 shown in FIG. 6(b) and the folded-in portion 27b of the second packaging material 20 overlap are folded inward in order as shown by the arrow M, and are superimposed on the widthwise center portion 27c of the bottom portion 27 previously folded, as shown in FIG. 6(c). Finally, the protruding portion 13c of the bottom sheet 13 of the first packaging material 10 constituting the folded-in portion 13b shown in FIG. 6(c) is folded forward as shown by the arrow N in FIG. 6(d) and superimposed on the previously folded sealing portion 35, and the state is maintained by the seal 40. The final sealing of the packaging bag 1 to maintain the packaged state may be performed by joining the sealing portion 35 by means of adhesive, heat sealing, or the like, in addition to using the seal 40.

[0031] As a result, the sandwich 100 is packaged in the packaging bag 1 that has been deformed into a shape that roughly conforms to the outer surface of the sandwich 100, as shown in Fig. 7. In this packaged state, the window portion 14 of the first packaging material 10 is positioned to face the ingredients 102 of the sandwich 100. Therefore, the ingredients 102 of the sandwich 100 can be seen through the window portion 14. While the first packaging material 10 is entirely made of paper, a paper material having visibility such as glassine paper is used as the paper material for the central sheet 12 that constitutes the window portion 14. This makes it easy to visually determine the type of sandwich 100 through the window portion 14.

[0032] The folded portion 27b of the bottom 27 of the second packaging material 20 constituting the sealing portion 35 is a flexible resin film, and therefore can be easily folded flat. As a result, even if the sealing portion 35 is folded multiple times, its thickness does not increase and it is less likely to become bulky.

[0033] The packaging bag 1 is opened by holding the opening strip 22 provided on the second packaging material 20 on the back side with the fingers, tearing the cutting tape 23 from the top 25 toward the bottom 27, and separating the center part 26 of the second packaging material 20 into left and right parts, and the sandwich 100 contained therein can be taken out from the second packaging material 20 side and eaten.

[0034] The packaging bag 1 according to the first embodiment is manufactured, for example, by a manufacturing line 50 shown in Fig. 8. By using the manufacturing line 50, one example of the manufacturing method of the present invention can be implemented.

[0035] 8, a first original roll 10S from which a plurality of first packaging materials 10 can be formed is transported in the direction of arrow H, and a second original roll 20S from which a plurality of second packaging materials 20 can be formed is transported in the direction of arrow K. The first original roll 10S and the second original roll 20S are transported synchronously and intermittently. In the production line 50, the following steps are performed: step A of attaching a cutting tape 23 to the second original roll 20S, step B of forming an opening strip 22 on the second original roll 20S, step C of overlapping the first original roll 10S with the second original roll 20S that has been through steps A and B, step D of forming a sealed portion 30 to form packaging bags 1 so as to be continuously arranged in the transport direction, step E of cutting the side sealed portion 32 of the sealed portion 30 in the transport direction to sequentially cut a plurality of packaging bags 1, and step F of forming a bottom notch 7a. The step D of forming the seal portion 30 includes a step D1 of forming the top seal portion 31 and a step D2 of forming the side seal portion 32.

[0036] In the production line 50, a plurality of packaging bags 1 are continuously produced in a horizontal state in which the length direction L of the packaging bag 1 is perpendicular to the conveying direction, and the horizontal state is alternately reversed. Therefore, the openings 34 of the packaging bags 1 adjacent to each other in the conveying direction are alternately arranged on both sides in the conveying direction.

[0037] As shown in Fig. 9, the first original web 10S is continuously manufactured by unwinding a central sheet original web 12S wound into a roll and side sheet original webs 15S on both sides of the central sheet original web 12S, and overlapping and joining the side edges of the side sheet original webs 15S to both sides of the central sheet original web 12S. The central sheet original web 12S is the original web for the central sheet 12 of the first packaging material 10. The side sheet original webs 15S are the original webs for the top sheet 11 and bottom sheet 13 of the first packaging material 10. Therefore, the top sheet 11 and bottom sheet 13 of the first packaging material 10 are made of the same paper material.

[0038] In step A, cutting tape 23 is attached at regular intervals to the upper surface of the unwound second raw web 20S. The upper surface to which cutting tape 23 is attached is the inner surface facing the containing section 33 of the packaging bag 1. The cutting tape 23 is attached to the second raw web 20S by, for example, pressing the cutting tape 23 against the second raw web 20S with a heat seal bar (not shown).

[0039] In process B, a cutter (not shown) is used to make a slit 21 in a portion adjacent to one end of the cutting tape 23 to form a tear strip 22. Since the packaging bags 1 are formed transversely to the conveyance direction and in alternately opposite directions, the attachment position of the cutting tape 23 and the formation position of the tear strip 22 are shifted alternately in the width direction of the second raw roll 20S.

[0040] In step C, the first raw web 10S is superimposed on the second raw web 20S conveyed through steps A and B. In step D, step D1 is performed in which the first raw web 10S and the second raw web 20S are sealed together by a heat seal bar 51 to form a top seal portion 31, followed by step D2 in which the first raw web 10S and the second raw web 20S are sealed together by a heat seal bar 52 to form a side seal portion 32. As shown in FIG. 10, steps D1 and D2 form a plurality of trapezoidal packaging bags 1 facing sideways, with openings 34 alternately formed on both sides in the conveying direction, so that the packaging bags 1 are continuously arranged in the conveying direction. In step D, the first raw web 10S and the second raw web 20S are sealed together so that the openings 34 remain on one side in the conveying direction, forming a seal portion 30.

[0041] In step E, as also shown in Fig. 10, the side seal portion 32 is cut in the conveying direction by a cutter (not shown). This sequentially cuts a plurality of packaging bags 1 to be obtained. In step F, the cutout portion 7a of the bottom 7 is formed by a cutter (not shown). As shown in Fig. 10, by cutting a plurality of packaging bags 1 horizontally to the conveying direction and such that the horizontal orientation is alternately reversed, even trapezoidal packaging bags 1 can be efficiently produced without waste of the first raw roll 10S and the second raw roll 20S.

[0042] The packaging bag 1 according to the first embodiment described above comprises a sheet-like first packaging material 10, a sheet-like second packaging material 20 that is bonded to the first packaging material 10 and forms a storage section 33 between the first packaging material 10 and the second packaging material 20 for storing the sandwich 100, and an opening 34 that opens the storage section 33 to the outside, and at least the first packaging material 10 of the first packaging material 10 and the second packaging material 20 has a window section 14 in at least a part thereof made of a visible paper material that allows the sandwich 100 stored in the storage section 33 to be viewed from the outside.

[0043] As a result, at least a portion of the first packaging material 10 is made of a paper material, which makes it possible to reduce the amount of resin used. Because paper materials have better printability than resin films, it is easy to print various indications such as product names, patterns, logos, etc. on the paper material portions (top sheet 11, center sheet 12, and bottom sheet 13) of the packaging bag 1. Furthermore, according to the packaging bag 1 of the first embodiment, the sandwich 100 inside can be visually confirmed from the outside through the window portion 14, and the type of sandwich 100 can be easily determined visually.

[0044] In the packaging bag 1 according to the first embodiment, it is preferable that the first packaging material 10 is entirely made of a paper material, including the window portion 14, and that the portion other than the window portion 14 is made of a paper material that is less visible than the paper material of the window portion 14.

[0045] As a result, the first packaging material 10, which occupies approximately half of the packaging bag 1, is made of paper, which allows for a significant reduction in the amount of resin used, and the sandwich 100 inside can be easily seen through the window portion 14 without having to construct the window portion 14 with a transparent resin film or the like.

[0046] In the packaging bag 1 according to the first embodiment, the second packaging material 20 has a folded-in portion 27b which becomes a sealing portion 35 that closes the opening 34, and it is preferable that at least the folded-in portion 27b is made of a resin film.

[0047] This makes it easier to fold the bottom 27 of the second packaging material 20 constituting the folded-in portion 27b into a flat shape, and prevents the sealing portion 35 from becoming thicker and more bulky even when it is folded multiple times.

[0048] In the packaging bag 1 according to the first embodiment, the food contained in the container portion 33 is a sandwich 100 having a right-angled triangular shape, and the window portion 14 is disposed at a position facing the ingredients 102 of the sandwich 100.

[0049] This allows the type of sandwich 100 based on ingredients 102 to be easily determined visually through window portion 14.

[0050] The manufacturing method of the packaging bag 1 according to the first embodiment includes the steps of: overlapping the first original roll 10S from which a plurality of first packaging materials 10 can be formed, and the second original roll 20S from which a plurality of second packaging materials 20 can be formed, while unwinding and transporting them in a predetermined transport direction; sealing the overlapped first original roll 10S and second original roll 20S to each other while leaving an opening 34 on one side in the transport direction to form a sealed portion 30, thereby forming the packaging bag 1 so that it is continuously lined up in the transport direction; and sequentially cutting a plurality of food packaging bags 1 by dividing the multiple sealed portions 30 in the transport direction.

[0051] This allows the packaging bag 1 according to the first embodiment to be suitably manufactured.

[0052] In the manufacturing method of the packaging bag 1 according to the first embodiment, it is preferable that the packaging bag 1 has a substantially trapezoidal shape and has an opening 34 at one end in its height direction (length direction L in FIG. 3), and that the openings 34 are arranged alternately on both sides of the conveying direction in adjacent packaging bags 1 in the conveying direction.

[0053] This allows the substantially trapezoidal packaging bag 1 to be efficiently manufactured without generating waste in either the first raw web 10S or the second raw web 20S.

[0054] Second embodiment Next, a second embodiment will be described with reference to FIGS. The packaging bag 2 according to the second embodiment differs from the first embodiment in that both the first packaging material 10 and the second packaging material 20 are made of a single sheet of paper material. In the following explanation, components having functions common to those of the first embodiment are given the same reference numerals and explanations thereof are omitted, and the explanation will focus on the differences.

[0055] Fig. 11 is an exploded perspective view of the packaging bag 2 of the second embodiment, Fig. 12 is a plan view of the packaging bag 2 of the second embodiment seen from the first packaging material 10 side (front side), Fig. 13 is a back view of the packaging bag 2 of the second embodiment seen from the second packaging material 20 side (rear side), and Fig. 14 is a cross-sectional view taken along line XIV-XIV in Fig. 13. As shown in these figures, the first packaging material 10 and the second packaging material 20 are both made of a single sheet, and the sheet is made of a paper material.

[0056] In the packaging bag 2 of the second embodiment, both the first packaging material 10 and the second packaging material 20 are made of a translucent paper material having visibility, such as glassine paper or cellophane paper. Such a paper material may be a paper material having a certain degree of water resistance, in which at least the inner surface facing the storage section 33 is laminated with a resin film such as OPP (biaxially oriented polypropylene). Since both the first packaging material 10 and the second packaging material 20 are made of a paper material having visibility, when the sandwich 100 is packaged, the portions of the first packaging material 10 and the second packaging material 20 facing the sandwich 100 can become window portions 14 through which the sandwich 100 can be viewed from the outside.

[0057] In the packaging bag 2 of the second embodiment, one of the first packaging material 10 and the second packaging material 20 may be made of a visible paper material such as glassine paper, and the other may be made of Western paper, Japanese paper, synthetic paper, craft paper, or the like that prevents the sandwich 100 inside from being seen. In this case, applying a visible paper material to the first packaging material 10 on the front side is preferable in that it looks good and the ingredients 102 are easily visible.

[0058] The second packaging material 20 has a slit 21 formed therein, thereby providing a tear strip 22. A cutting tape 23 is attached to the inner surface of the second packaging material 20 in a manner corresponding to the tear strip 22.

[0059] The packaging bag 2 is formed into a bag shape by overlapping a first packaging material 10 and a second packaging material 20 with the same shape, and bonding together the seal portions 30 on three sides, i.e., the top seal portion 31 and the side seal portions 32.

[0060] In the packaging bag 2 of the second embodiment, at least one of the first packaging material 10 and the second packaging material 20 may be composed of a sheet in which multiple sheets made of a paper material are integrated together, as in the first packaging material 10 of the first embodiment described above. In the packaging bag 2 of the second embodiment, the cutting tape 23 may also be made of a paper material.

[0061] In the packaging bag 2 of the second embodiment, both the first packaging material 10 and the second packaging material 20 are made of paper material. This makes it possible to use no resin film at all or to use a significantly reduced amount of resin, thereby making it possible to significantly reduce the amount of resin used.

[0062] The present invention is not limited to the above-described embodiments, and various modifications can be made thereto. For example, the first packaging material 10 of the first embodiment may be made of a single sheet having visibility, such as glassine paper, as in the second embodiment, instead of being made of multiple, divided sheets of paper material that are integrated together. Alternatively, the first packaging material 10 may not be made entirely of paper material, but may be made of a paper material with a portion serving as a window and the other portions made of film. In this case, the film does not need to be transparent or translucent. In the first embodiment, the second packaging material 20 may be a combination of a paper material and a film, instead of being configured from a single resin film, or may be configured from a paper material only. [Explanation of symbols]

[0063] 1, 2 Food packaging bags 10 First packaging material 10S First roll 14 Window section 20 Second Packaging Material 20S Second Original Fabric 27b Fold-in section 30 Seal part 33 Storage unit 34 Opening 100 Sandwich (food) 102 Ingredients

Claims

1. The packaging device comprises a sheet-like first packaging material, a sheet-like second packaging material that is attached to the first packaging material and forms a storage space for storing food between the first packaging material and the second packaging material, and an opening that opens the storage space to the outside, A food packaging bag, wherein both the first packaging material and the second packaging material are made of a visible paper material that allows the food contained in the storage section to be seen from the outside, and the portions of the first packaging material and the second packaging material that face the food form a window section.

2. The food contained in the container is a sandwich having a substantially triangular shape, The food packaging bag according to claim 1 , wherein the window portion is positioned opposite an ingredient of the sandwich.

3. A method for producing the food packaging bag according to claim 1 or 2, comprising the steps of: a step of superimposing a first web from which a plurality of the first packaging materials can be formed and a second web from which a plurality of the second packaging materials can be formed, while feeding and transporting the first web and the second web in a predetermined transport direction; a step of sealing the overlapped first and second rolls together to form a seal portion while leaving the opening on one side in the conveying direction, thereby forming the food packaging bags so as to be continuously arranged in the conveying direction; and a step of sequentially cutting a plurality of the food packaging bags by dividing the plurality of the sealed portions in the conveying direction to obtain a plurality of the food packaging bags.

4. The method for manufacturing food packaging bags described in claim 3, wherein the food packaging bag has a substantially trapezoidal shape and has the opening at one end in its height direction, and the openings are arranged alternately on both sides of the conveying direction in the food packaging bags adjacent to each other in the conveying direction.

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