Food packaging bags

Abstract

To provide a properly and surely openable food packaging bag.SOLUTION: A food packaging bag 1 has a bag body 10 in which a pair of sheets 2, 3 having a shape of one end side width larger than the other end side width are overlapped, and three ways are sealed by a top part joint part 11 of one end side and side part joint parts 12, 12 of both side parts with the other end side being an opening 13. The food packaging bag 1 has a notch line 32 formed at a part near to one side part joint part 12 from a center line in the second direction orthogonal to the first direction, out of one sheet 3 in the bag body 10, the notch line 32 being a starting point for tearing the one sheet 3 in a prescribed width toward the side part joint part 12 on the opposite side along the second direction, and a covering piece 5 covering the notch line 32 from an inner face side or an outer face side of the one sheet 3 and jointed to the one sheet 3.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a food packaging bag for packaging food. [Background technology]

[0002] There are foods such as sandwiches that have triangular sides (mainly right-angled triangles) and a three-dimensional shape (a triangular prism lying on its side) with a certain width. A typical food packaging bag for packaging such foods is shown in Fig. 20, and one such bag is well known, for example, as described in Patent Document 1.

[0003] The food packaging bag 1' comprises a bag body 10' and a header portion 15'. The bag body 10' is formed by overlapping a pair of sheets 2', 3', each having a shape in which one end in a first direction is wider than the other end, and is sealed on three sides by a top joint portion 11' at one end and side joint portions 12', 12' on both side edges, with the other end forming an opening 13'. The header portion 15' is formed by joining the protruding pieces of the sheets 2', 3' protruding from the top joint portion 11' to each other at appropriate locations and integrating them.

[0004] In the second sheet 3' in the header portion 15', for example, an inverted U-shaped cut line 32' is formed, and a free piece 33' is formed with the cut line 32' as its outline. On the inner surface of the second sheet 3', an opening strip 34' such as cutting tape is joined from the free piece 33' along the first direction toward the other end of the second sheet 3'.

[0005] When eating food packaged in the food packaging bag 1', the free piece 33' is picked up and pulled down. This pulls the opening strip 34', causing the second sheet 3' to tear in the first direction by a predetermined width, forming an opening in the second sheet 3'. The food can be removed from this opening. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-171326 Summary of the Invention [Problem to be solved by the invention]

[0007] However, as will be described later, the tear direction of the second sheet 3' is primarily a second direction perpendicular to the first direction, i.e., the width direction of the second sheet 3'. This means that the tearing of the second sheet 3' by the tearing strip 34' occurs against the tearing direction of the second sheet 3'. For this reason, in conventional food packaging bags, when opening, the tearing of the second sheet 3' may deviate from the tearing strip 34' and proceed in an unexpected direction. If the deviation is significant, opening may become difficult. In recent years, food packaging bags using paper sheets have begun to be proposed from an environmental perspective, but paper sheets have a stronger tearing direction in the second direction than plastic sheets, resulting in significant problems with opening.

[0008] The present invention has been made in view of the above circumstances, and has as its object to provide a food packaging bag that can be opened properly and reliably. [Means for solving the problem]

[0009] The food packaging bag according to the present invention comprises: A food packaging bag comprising a pair of overlapping sheets each having a shape in which one end side is wider than the other end side in a first direction, the bag body being sealed on three sides by a top joint at one end side and side joints at both sides, and the other end side being an opening, A cut line is formed in one sheet of the bag body at a location closer to one side joint portion than the center line in a second direction perpendicular to the first direction, The cut line is formed so that both end points are close to the opposite side joint portion and are located on a mountain fold line bent by the side of the food to be packaged or on the opposite side joint portion side of the mountain fold line, A score line that serves as a starting point for tearing one sheet to a predetermined width along the second direction toward the opposite side joint; A free piece formed by forming a cut line and having the cut line as an outline; Inside of one sheet Side orand a covering piece that covers the cut line and is joined to one of the sheets. 、 When food is packaged and the food is ready, loose pieces protrude. It is a food packaging bag.

[0010] Here, as one embodiment of the food packaging bag according to the present invention, The score line is formed between the inner edge of the top joint and the mountain fold line formed by the bottom surface of the packaged food. The above configuration can be adopted.

[0011] Also, As another aspect of the food packaging bag according to the present invention, The cut line includes a first portion consisting of a line inclined along the side joint portion, a second portion consisting of a line extending in the second direction from an end point of the first portion on the top joint portion side, and a third portion consisting of a line extending in the second direction from an end point of the first portion on the opening side longer than the second portion. The above configuration can be adopted.

[0014] In addition, as another aspect of the food packaging bag according to the present invention, A middle section including a section where a cut line is formed is defined on one of the sheets, A paper sheet is used in the middle section The above configuration can be adopted.

[0015] In addition, as yet another aspect of the food packaging bag according to the present invention, The covering piece has a sloped hypotenuse along the side joint. The above configuration can be adopted.

[0016] Also, in this case, The covering piece is joined to one of the sheets at a side joint at the oblique side, and is joined to the other of the sheets at a joint that surrounds the cut line and includes the side joint as a part. The above configuration can be adopted. [Effects of the Invention]

[0017] When opening the food packaging bag according to the present invention, the tearing direction of the sheet starting from the cut line coincides with the tearing direction of the sheet. This allows the sheet to be torn cleanly along the second direction, and a tearing section of a uniform width is neatly formed. Therefore, the food packaging bag according to the present invention can be opened properly and reliably. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is an exploded perspective view of a food packaging bag according to a first embodiment. [Figure 2] FIG. 2 is a front view of the food packaging bag according to the first embodiment. [Figure 3] FIG. 3 is a rear view of the food packaging bag according to the first embodiment. [Figure 4] Fig. 4(a) is a front view of the first sheet of the food packaging bag according to embodiment 1. Fig. 4(b) is a cross-sectional view taken along line AA in Fig. 4(a). [Figure 5] Fig. 5(a) is a front view of the second sheet of the food packaging bag according to embodiment 1. Fig. 5(b) is a cross-sectional view taken along line BB in Fig. 5(a). [Figure 6] FIG. 6 is a perspective view of the food package according to the first embodiment, in which food is packaged in the food packaging bag according to the first embodiment, as seen from the front side. [Figure 7] FIG. 7 is a perspective view of the food packaging body according to the first embodiment as viewed from the rear side. [Figure 8] 8(a) and (b) are perspective views showing how the food package according to the first embodiment is opened. [Figure 9] FIG. 9 is an explanatory diagram of a manufacturing process of the first sheet material and the second sheet material for the food packaging bag according to the first embodiment. [Figure 10] FIG. 10 is an explanatory diagram of the manufacturing process of the second raw sheet for the food packaging bag according to the first embodiment, and is a continuation of FIG. [Figure 11] FIG. 11 is a continuation of FIG. [Figure 12] FIG. 12 is an explanatory diagram of the manufacturing process of the packaging bag for food according to the first embodiment. [Figure 13] FIG. 13 is a rear view of the packaging bag for food according to the first alternative embodiment. [Figure 14] FIG. 14 is a perspective view of a food package according to another embodiment 1, in which food is packaged in the food packaging bag according to another embodiment 1, as seen from the back side. [Figure 15]FIG. 15 is an explanatory diagram of a manufacturing process of the packaging bag for food according to the first alternative embodiment. [Figure 16] FIG. 16 is a rear view of the packaging bag for food according to the second alternative embodiment. [Figure 17] FIG. 17 is a perspective view of a food package according to another embodiment 2, in which food is packaged in a food packaging bag according to another embodiment 2, as seen from the rear side. [Figure 18] FIG. 18 is a rear view of the packaging bag for food according to the third alternative embodiment. [Figure 19] 19(a) to 19(g) are explanatory diagrams of various examples of the cut lines. [Figure 20] FIG. 20 is a rear view of a conventional food packaging bag. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, a food packaging bag used for packaging sandwiches will be described as one embodiment of the food packaging bag according to the present invention with reference to Figs. 1 to 12.

[0020] As shown in Figures 1 to 3, the food packaging bag 1 comprises a bag body 10 and a header portion 15. The bag body 10 is formed by overlapping and joining a pair of sheets (a first sheet 2 and a second sheet 3). The first sheet 2 is also called the front sheet, and the second sheet 3 is also called the back sheet. The pair of sheets are shaped so that one end is longer than the other in mutually orthogonal directions, and the other end is wider than the other end. The bag body 10 is joined and sealed on three sides by a top joint portion 11 at one end and side joint portions 12, 12 on both sides, and the other end forms an opening 13. The header portion 15 is formed by joining the protruding pieces of the sheets 2, 3 protruding from the top joint portion 11 at appropriate locations to form an integrated body. In the following, the one of the directions (the up-down direction in Figures 2 and 3) will be referred to as the "longitudinal direction" or "first direction," and the other of the directions (the left-right direction in Figures 2 and 3) will be referred to as the "width direction" or "second direction."

[0021] The first sheet 2 has a body portion 20 and a tip portion 21 (the protruding piece). The body portion 20 has a shape that gradually widens from one end to the other end. The tip portion 21 has a narrow shape that extends from one end of the body portion 20.

[0022] The second sheet 3 includes a body portion 30 and a tip portion 31 (the protruding piece). The body portion 30 has a shape that gradually widens from one end to the other. The tip portion 31 has a narrow shape that extends from one end of the body portion 30.

[0023] The body portions 20, 30 are trapezoidal. Therefore, one end of the body portions 20, 30 (and the other end of the tip portions 21, 31 that coincide therewith) is linear and perpendicular to the longitudinal direction. In other words, one end of the body portions 20, 30 is linear and parallel to the width direction. Both side edges of the body portions 20, 30 and both side edges of the tip portions 21, 31 are linear and inclined with respect to the longitudinal direction. However, the other end sides of both side edges of the body portions 20, 30 are missing by the cutouts 14. As a result, the other end sides of the body portions 20, 30 are narrower by the amount of the cutouts 14.

[0024] As shown in Fig. 4, the first sheet 2 is divided into a plurality of regions in the longitudinal direction. Specifically, the first sheet 2 is divided into three regions: an upper section 22A, a middle section 22B, and a lower section 22C. The upper section 22A is divided into the upper portion and the tip section 21 of the body section 20. The lower section 22C is divided into the lower portion of the body section 20. The middle section 22B is divided between the upper section 22A and the lower section 22C, i.e., into the middle portion of the body section 20. The upper section 22A and the lower section 22C have the same height dimension.

[0025] The first sheet 2 is made into a single sheet by overlapping three sheets (a middle separate sheet 23 and upper and lower end separate sheets 23, 23) at their edges (overlapped portion 24) and joining the overlapped portion 24 along the width direction of the first sheet 2 (jointed portion 25). In this embodiment, the jointed portion 25 is a strip-shaped seal having a predetermined width, formed by welding using a heating bar or a heating roller. At the overlapped portion 24, the edge of the end separate sheet 23 is positioned on the outer surface of the edge of the middle separate sheet 23, and the edge of the middle separate sheet 23 and the edge of the end separate sheet 23 are overlapped so that the outer surface of the edge of the middle separate sheet 23 faces the inner surface of the edge of the end separate sheet 23.

[0026] The intermediate divided sheet 23 is a heat-sealable plastic sheet (film) made of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or the like. For example, the sheet is a biaxially oriented polypropylene (OPP) sheet (film) or a solid polypropylene (CPP) sheet (film). Alternatively, the sheet is a laminated sheet (film). As one form of laminated sheet (film), the sheet is formed by laminating, from the outer surface side, a base layer, an adhesive layer, and a resin layer. Resins such as polyethylene terephthalate (PET), polypropylene (PP), and polyethylene (PE) are used for the base layer. Dry lamination, extrusion lamination, and the like are used for the adhesive layer. Resins such as polypropylene (PP) and polyethylene (PE) are used for the resin layer. The term "polypropylene sheet (film)" not only refers to 100% pure polypropylene sheets (films), but also includes sheets (films) that contain polypropylene as the main component and other components (e.g., other resin components such as polyethylene). It should be noted that the term "sheet" is not defined by thickness, but is a concept that includes film (the same applies hereinafter).

[0027] In contrast, the upper and lower end divided sheets 23, 23 are made of paper, unbleached kraft paper, Japanese paper, mixed paper, synthetic paper, glassine paper, paper-like material (collectively referred to as "paper"), or are sheets (films) primarily made of these materials (collectively referred to as "paper sheets" (films"). The paper may be paper containing bio-based polyethylene terephthalate (bio-based PET, or so-called bio-PET). If necessary, the sheet may be heat-sealable entirely or partially on at least one of the inner and outer sides. For example, the sheet may be a laminated sheet (film) in which paper is laminated as an outer layer with a plastic sheet (film) as an inner layer. One form of laminated sheet (film) is formed by laminating, from the outer side, a base layer, an adhesive layer, and a resin layer. Paper is used as the base layer. Dry lamination, extrusion lamination, etc. are used as the adhesive layer. Resins such as polypropylene (PP) and polyethylene (PE) are used as the resin layer. As an example, the base layer has a basis weight of 12 g / m 2 About 15g / m 2 The adhesive layer is a dry laminate, and the resin layer is biaxially oriented polypropylene (OPP).

[0028] Alternatively, the upper and lower end separate sheets 23, 23 may be made of ordinary cellophane, moisture-proof cellophane, cellophane-based material, or cellophane-like material (collectively referred to as "cellophane"), or may be made primarily of these materials (films) (collectively referred to as "cellophane sheets" (films"). The sheet may be heat-sealable on at least one of the inner and outer surfaces, either entirely or partially where necessary. For example, the sheet may be a laminated sheet (film) with cellophane as the outer layer and a plastic sheet (film) as the inner layer. One form of laminated sheet (film) is formed by laminating, from the outer surface side, a base layer, an adhesive layer, and a resin layer. Cellophane is used as the base layer. Dry lamination, extrusion lamination, etc. are used as the adhesive layer. Resins such as polypropylene (PP) and polyethylene (PE) are used as the resin layer. As an example, the base layer is ordinary cellophane or moisture-proof cellophane, the adhesive layer is a dry laminate, and the resin layer is biaxially oriented polypropylene (OPP).

[0029] Upper portion 22A corresponds to the upper end separate sheet 23. Middle portion 22B corresponds to the portion of intermediate separate sheet 23 excluding the upper and lower overlapping portions 24, 24. Lower portion 22C corresponds to the lower end separate sheet 23. As a result, in first sheet 2, upper portion 22A and lower portion 22C become opaque (or translucent) portions when the upper and lower end separate sheets 23, 23 are paper sheets, and become transparent portions when the upper and lower end separate sheets 23, 23 are cellophane sheets, with middle portion 22B being a transparent portion that allows the interior to be seen.

[0030] As shown in FIG. 5, the second sheet 3 is divided into multiple regions in the longitudinal direction. Specifically, the second sheet 3 is divided into three regions: an upper section 35A, a middle section 35B, and a lower section 35C. The upper section 35A is defined in the tip section 31. The lower section 35C is defined in the lower part of the body section 30. The middle section 35B is defined between the upper section 35A and the lower section 35C, i.e., the part excluding the lower part of the body section 30. The middle section 35B has a height dimension greater than the middle section 22B of the first sheet 2. The upper section 35A and the lower section 35C have the same height dimension. The upper section 35A and the lower section 35C have a height dimension smaller than the upper section 22A and the lower section 22C of the first sheet 2.

[0031] The second sheet 3 is formed by overlapping three sheets (a middle separate sheet 36 and upper and lower end separate sheets 36, 36) at their edges (overlapped portion 37) and joining the overlapped portion 37 along the width direction of the second sheet 3 (jointed portion 38) to form a single sheet. In this embodiment, the jointed portion 38 is a strip-shaped seal having a predetermined width, formed by welding using a heating bar or a heating roller. At the overlapped portion 37, the edge of the end separate sheet 36 is positioned on the inner side of the edge of the middle separate sheet 36, and the edge of the middle separate sheet 36 and the edge of the end separate sheet 36 are overlapped such that the inner surface of the edge of the middle separate sheet 36 faces the outer surface of the edge of the end separate sheet 36.

[0032] The middle divided sheet 36 is a paper sheet or a cellophane sheet, while the upper and lower divided sheets 36, 36 are plastic sheets.

[0033] Upper portion 35A corresponds to the portion of upper divided sheet 36 excluding overlapping portion 37. Middle portion 35B corresponds to the middle divided sheet 36. Lower portion 35C corresponds to the portion of lower divided sheet 36 excluding overlapping portion 37. As a result, in second sheet 3, upper portion 35A and lower portion 35C are transparent portions, and middle portion 35B is an opaque (or translucent) portion if middle divided sheet 36 is a paper sheet, and is a transparent portion if middle divided sheet 36 is a cellophane sheet.

[0034] 2 and 3, the top joint 11 is formed by welding the sheets 2 and 3 along one end of the body portions 20 and 30. In this embodiment, the top joint 11 is formed by welding using a heating bar, and is a strip-shaped seal having a predetermined width.

[0035] The side joints 12 are formed by welding the sheets 2 and 3 along the side edges (hypotenuses) of the body portions 20 and 30 and the side edges (hypotenuses) of the tip portions 21 and 31. In this embodiment, the side joints 12 are formed by welding using a heating bar and are strip-shaped seals having a predetermined width. The width of the side joints 12 is smaller than the width of the top joint 11. Specifically, the side joints 12 have a width of 2 mm or more, more preferably 3 mm or more, and 5 mm or less, more preferably 4 mm or less.

[0036] The interior of the bag body 10 constructed in this manner serves as a food storage area. An inner sheet 4 is attached to the inner surface of the first sheet 2 in the bag body 10. The other end of the inner sheet 4 is joined at two points using a point seal or the like (joint 40), and one end is a free end. This allows the inner sheet 4 to adhere to the surface of the food and follow its movement even if the food moves within the storage area. Therefore, the first sheet 2 does not get dirty and its appearance is not damaged.

[0037] 3 and 5, a cut line 32 is formed in the second sheet 3 of the bag body 10 at a location closer to one side joint 12 than the center line in the width direction, more specifically, at a predetermined location in the flat area corresponding to the side of the food to be packaged. The cut line 32 is formed by a full cut line. The cut line 32 serves as a starting point for tearing the second sheet 3 to a predetermined width along the width direction toward the opposite side joint 12.

[0038] The score line 32 includes a first portion 32a, a second portion 32b, and a third portion 32c. The first portion 32a is a line that slopes along the side joint 12. The second portion 32b is a line that extends from the end point of the first portion 32a on the top joint 11 side along the width direction of the second sheet 3. The third portion 32c is a line that extends from the end point of the first portion 32a on the opening 13 side along the width direction of the second sheet 3. As a result, the score line 32 is formed so that both end points 32d, 32d of the score line 32 are close to the opposite side joint 12, and the ends of the score line 32 are parallel to the width direction of the second sheet 3.

[0039] Here, the mountain fold line of the second sheet 3 along which the second sheet 3 is folded by the side of the food to be packaged, more specifically, the mountain fold line of the second sheet 3 corresponding to the intersection line between the back and side of the food to be packaged (this coincides with a line along the longitudinal direction of the second sheet 3 that passes through the intersection of the inner edge of the top joint 11 and the inner edge of the side joint 12), is designated as L1, and the mountain fold line of the second sheet 3 along which the second sheet 3 is folded by the bottom of the food to be packaged, more specifically, the mountain fold line of the second sheet 3 that corresponds to the rear edge of the bottom of the food to be packaged, is designated as L2. In this case, the cut line 32 is formed between the inner edge of the top joint 11 and the mountain fold line L2. More specifically, the cut line 32 is formed so that one end point 32d of the cut line 32 is located near the inner edge of the top joint 11 and the other end point 32d of the cut line 32 is located near the mountain fold line L2. The cut line 32 is formed so that both end points 32d, 32d of the cut line 32 are located near the mountain fold line L1.

[0040] Then, a free piece 33 is formed in the second sheet 3 of the bag body 10 by forming the cut line 32. The free piece 33 has the cut line 32 as its outline, a fixed end between both end points 32d, 32d of the cut line 32, and a free end on the side joint portion 12 side.

[0041] The food packaging bag 1 includes a covering piece 5. The covering piece 5 is joined to the second sheet 3 from the inner surface side of the second sheet 3, covering the cut line 32 (joint 50). The covering piece 5 is a sealant that prevents foreign matter from entering the interior through the cut line 32. The covering piece 5 has a hypotenuse that slopes along the side joint 12. More specifically, the covering piece 5 has a right-angled trapezoid or right-angled triangle shape. The joint 50 is formed along the outer edge of the covering piece 5 excluding the hypotenuse, and is formed to surround the cut line 32 in cooperation with the side joint 12.

[0042] The covering piece 5 is a plastic sheet. The covering piece 5 is bonded to the inner surface of the second sheet 3 by thermal bonding or self-adhesion after a coating agent (partial coating agent) such as a heat-sensitive adhesive is applied to the entire surface or a corresponding portion of the inner surface (the surface facing the second sheet 3). The use of the coating agent makes the bonded portion 50 not peelable with a small force, but creates a weak bond that can be peeled off when a person applies a certain amount of force. The covering piece 5 may also be a paper sheet or a cellophane sheet.

[0043] The method for packaging food using the food packaging bag 1 is as follows. First, the opening 13 is opened, and the food is placed into the bag body 10 from the apex side. After that, the excess sheet piece on the opening 13 side, which extends from the outer edge of the bottom of the food into a rectangular tube shape, is folded appropriately to close and seal the opening 13. This completes the food package 7, as shown in Figures 6 and 7. The food package 7 is maintained in an airtight state by sealing the top joint 11, side joints 12, 12, and opening 13, and by sealing the cut line 32 with the covering piece 5 (and joint 50). This prevents outside air from entering the inside, and the intended quality of the packaged food 6 is maintained.

[0044] When eating the food 6, as shown in Fig. 8(a), the free piece 33 is picked up and pulled along the width direction of the second sheet 3 toward the opposite side joint portion 12. This causes the second sheet 3 (middle portion 35B) to tear at a predetermined width along the width direction, forming an opening portion in the second sheet 3 (middle portion 35B). The food 6 can be removed from this opening portion.

[0045] The method for manufacturing the food packaging bag 1 is as follows: The food packaging bag 1 is manufactured through the following steps: i) a step (first step) of manufacturing a first sheet material 2X having a continuous first sheet 2, as shown in Fig. 9, ii) a step (second step) of manufacturing a second sheet material 3X having a continuous second sheet 3, as shown in Figs. 9 to 11, and iii) a step (third step) of manufacturing the food packaging bag 1 from the first sheet material 2X and the second sheet material 3X, as shown in Fig. 12.

[0046] Due to their shape, this type of trapezoidal food packaging bags 1 are manufactured so that they are oriented transversely to the conveyance direction of the raw sheet webs 2X, 3X and have alternately opposite orientations. That is, food packaging bags 1 having an opening 13 on one side in the width direction (TD) perpendicular to the conveyance direction (MD) of the raw sheet webs 2X, 3X and a header portion 15 on the other side in the width direction, and food packaging bags 1 having an opening 13 on the other side in the width direction and a header portion 15 on one side in the width direction, are manufactured alternately. In Figures 10 to 12, the configuration of the former food packaging bags 1 is indicated by the letter "A" after the reference numeral, and the configuration of the latter food packaging bags 1 is indicated by the letter "B" after the reference numeral.

[0047] As shown in FIG. 9, in the first step, two separate sheet rolls are rotatably supported: one roll of a separate sheet roll 23X, in which a middle separate sheet 23 is continuously wound, and the other roll of a separate sheet roll 23X, in which an end separate sheet 23 is continuously wound. The pair of end separate sheet rolls 23X, 23X have the same width. The middle separate sheet roll 23X and the pair of end separate sheet rolls 23X, 23X are fed from the respective sheet rolls. The pair of end separate sheet rolls 23X, 23X are fed so as to sandwich the middle separate sheet roll 23X therebetween, and the side edges of the middle separate sheet roll 23X and the side edges of the end separate sheet roll 23X are overlapped (overlapped portion 24), and the overlapped portion 24 is joined to form a single separate sheet roll.

[0048] The second step is the same as the first step. The second step further includes: i) a step of forming score lines 32 in the second sheet raw web 3X as shown in Fig. 10, more specifically, a step of forming score lines 32 in the second sheet raw web 3X and forming free pieces 33 by the formation of the score lines 32 (step 2-1); and ii) a step of arranging covering pieces 5 on the inner surface of the second sheet raw web 3X so as to cover the score lines 32 and the free pieces 33 and joining the covering pieces 5 to surround the score lines 32 and the free pieces 33 as shown in Fig. 11 (step 2-2).

[0049] As shown in Fig. 10, in step 2-1, the cut lines 32, 32 of adjacent food packaging bags 1, 1 are formed close to each other. As shown in Fig. 11, in step 2-2, a rectangular (oblong) covering piece 5 is used that is large enough to cover two adjacent sets of cut lines 32, 32 and free pieces 33, 33. The covering piece 5 is formed by cutting a sheet material roll unwound from a sheet material roll (not shown, but arranged to the side of the second sheet material 3X) to a predetermined size, and is supplied from the side of the second sheet material 3X.

[0050] The sheet raw rolls 2X and 3X are thus manufactured. After being wound into a roll, the roll is set in a bag-making device, or the sheet raw rolls 2X and 3X are manufactured by the bag-making device and then continue to be transported, and then proceed to the third process.

[0051] As shown in Figure 12, the third step includes overlapping the first sheet raw material 2X, to which the inner sheet 4 has been joined, and the second sheet raw material 3X with their inner surfaces facing each other, and transporting them intermittently in this state, while i) forming the top joint 11 (step 3-1), ii) forming the side joint 12 (step 3-2, which may be performed simultaneously with step 3-1), iii) cutting and dividing the side joint 12 along the midline of the side joint 12 to individually separate the food packaging bags 1 (step 3-3), and iv) forming the cutouts 14 (step 3-4).

[0052] In step 3-3, along with the cutting and division of the side joints 12, the covering pieces 5 are also cut and divided, and each covering piece 5 has a right-angled trapezoidal or right-angled triangular shape as described above. The joints 50 are also cut and divided in the same manner.

[0053] The overall flow of the third step is generally the same as that described in Japanese Patent Application Laid-Open No. 2005-219319. However, in this patent document, the side joints are formed by fusion cutting. In contrast, in this embodiment, the side joints 12 are formed by welding and cutting. For welding, a heated bar having a width equal to the width of the side joints 12, 12 of adjacent food packaging bags 1, 1, i.e., twice the width of the side joints 12, is used. For cutting, a Thomson blade is used. Note that steps 3-3 and 3-4 may be performed simultaneously by punching out the food packaging bag 1 using a full-circumference Thomson blade.

[0054] As described above, in the food packaging bag 1 according to this embodiment, the tear direction of the second sheet 3 (the paper sheet or cellophane sheet that constitutes the middle section 35B) is primarily the conveyance direction (MD) of the second sheet roll 3X, so when opening, the tear direction of the second sheet 3 starting from the cut line 32 coincides with the tear direction of the sheet being torn. As a result, the second sheet 3 is torn cleanly across the width, and a tear section of a uniform width is neatly formed. Therefore, the food packaging bag 1 according to this embodiment can be opened properly and reliably.

[0055] Furthermore, in the food packaging bag 1 according to this embodiment, the cut line 32 is formed between the inner edge of the top joint portion 11 and the mountain fold line L2 that is folded by the bottom surface of the packaged food 6. As a result, as shown in Figure 8(b), tearing of the second sheet 3 starting from the cut line 32 occurs mainly in the flat area of ​​the second sheet 3 in the bag body 10 that corresponds to the back surface of the packaged food 6. Therefore, the food packaging bag 1 according to this embodiment can be opened more appropriately and reliably.

[0056] Furthermore, in the food packaging bag 1 according to this embodiment, the cut line 32 is formed so that one end point 32d of the cut line 32 is located near the inner edge of the top joint portion 11 and the other end point 32d of the cut line 32 is located near the mountain fold line L2 that is folded by the bottom surface of the packaged food 6. Therefore, the food packaging bag 1 according to this embodiment can form a large opening, as shown in Figure 8(b), allowing the food 6 to be removed smoothly.

[0057] Furthermore, in the food packaging bag 1 according to this embodiment, the cut line 32 is formed so that both end points 32d, 32d of the cut line 32 are close to the opposite side joint 12, and are positioned near the mountain fold line L1 along which the cut line 32 is folded by the side of the food 6 to be packaged. As a result, as shown in FIG. 7 , the free piece 33 protrudes from the flat area of ​​the second sheet 3 in the bag body 10 that corresponds to the back surface of the food 6 to be packaged, making it easy to pick up. Therefore, in the food packaging bag 1 according to this embodiment, the position of the free piece 33 can be quickly recognized, and the free piece 33 can be easily picked up, allowing for smooth opening. Note that "the end point 32d of the cut line 32 is positioned near the mountain fold line L1" includes any of the following: the end point 32d is positioned on the mountain fold line L1; the end point 32d is positioned closer to the side joint 12 than the mountain fold line L1; and the end point 32d is positioned on the opposite side.

[0058] Furthermore, in the food packaging bag 1 according to this embodiment, a paper sheet or cellophane sheet is used for part of the sheets 2 and 3. Paper sheets and cellophane sheets are more susceptible to creases than plastic sheets. As a result, the sheets 2 and 3 are folded sharply at each side of the food package 7, giving the food package 7 a sharp appearance. Therefore, the food packaging bag 1 according to this embodiment has the effect of providing the food package 7 with excellent appearance, stability, and therefore excellent self-standing ability.

[0059] Furthermore, paper sheets and cellophane sheets are more rigid (harder) than plastic sheets. This provides stiffness to sheets 2 and 3, which has the effect of improving the self-standing ability of food packaging 7. The stiffness of sheets 2 and 3 also improves the stiffness of food packaging 7. Therefore, food packaging bag 1 according to this embodiment is highly effective in preventing food 6 from losing its shape.

[0060] Furthermore, the food packaging bag 1 according to this embodiment uses a paper sheet or cellophane sheet, which allows for a reduction in the amount of plastic used. In recent years, waste plastic has become a global environmental problem, and the food packaging bag 1 according to this embodiment is an effective solution to this environmental problem.

[0061] Furthermore, in the food packaging bag 1 according to this embodiment, the upper section 22A of the first sheet 2 is defined as the upper section and header section 15 of the bag body 10, and the lower section 22C is defined as the lower section of the bag body 10. As a result, when the upper section 22A and the lower section 22C are made of paper, in the food package 7, the upper and lower sections of the upright food 6 are hidden by the opaque upper section 22A and lower section 22C, and only the center of the food 6 is visible through the transparent middle section 22B. In other words, only the center section of the food 6, which looks the most delicious, is visible and emphasized. Therefore, the food packaging bag 1 according to this embodiment can stimulate the consumer's desire to purchase the food in the food package 7.

[0062] Furthermore, in the food packaging bag 1 according to this embodiment, the side joint portions 12 are formed in a strip shape with a predetermined width along the side edges of the bag body 10 and the header portion 15. As a result, when the food packaging bag 7 is completed, the side joint portions 12 are in a folded-back state as shown in FIGS. 6 and 7. This causes the header portion 15 to stand upright, with pillars formed on both sides. Furthermore, the header portion 15 is in a flat state, extending straight from the front portion of the bag body 10. Therefore, the food packaging bag 1 according to this embodiment can improve the appearance when completed as a food packaging bag 7, and can make the markings on the header portion 15 easier to see when displayed in a store such as a convenience store.

[0063] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

[0064] In the above embodiment, the cut line 32 is formed on one side of the second sheet 3. However, the present invention is not limited to this. The cut line 32 may be formed on the other side of the second sheet 3. Alternatively, as shown in Figures 13 to 15, the cut line 32 may be formed on both sides of the second sheet 3. In this case, the package can be opened from either the left or right side.

[0065] In the above embodiment, the cut line 32 is formed in a planar region of the second sheet 3 of the bag body 10 that corresponds to the side of the food 6 to be packaged. However, the present invention is not limited to this. The cut line 32 may be formed in the second sheet 3 of the bag body 10 so as to largely cross the mountain fold line L1 along which the second sheet 3 is folded by the side of the food 6 to be packaged. Alternatively, as shown in Figures 16 and 17, the cut line 32 may be formed in a planar region of the second sheet 3 of the bag body 10 that corresponds to the back of the food 6 to be packaged. A POS label or food label 8 may be affixed to this planar region.

[0066] In the above embodiment, the covering piece 5 covers the cut line 32 from the inner surface side of the second sheet 3. However, the present invention is not limited to this. As shown in FIG. 18 , the covering piece 5 may cover the cut line 32 from the outer surface side of the second sheet 3. In this case, the covering piece 5 is releasably bonded to the outer surface of the second sheet 3 except for a portion. However, the covering piece 5 is bonded to the release piece 33 with a stronger bonding strength than the outer surface of the second sheet 3. A portion of the covering piece 5 (unbonded portion) serves as a gripping portion 5a. The covering piece 5 may be a label. To open the package, the gripping portion 5a of the covering piece 5 is grasped and pulled along the width direction of the second sheet 3 toward the opposite side bond portion 12.

[0067] The shape of the cut line 32 in the above embodiment is merely an example. Various shapes can be adopted for the cut line 32. The cut line 32 shown in FIG. 19(a) is a cut line in which the first portion 32a is formed along the longitudinal direction of the second sheet 3. The cut line 32 shown in FIG. 19(b) is a cut line formed by a curve. The cut line 32 shown in FIG. 19(c) is a cut line in which the end of the cut line 32 is inclined with respect to the width direction of the second sheet 3. The cut line 32 shown in FIG. 19(d) is a cut line that does not form a free piece 33. This can be used in a configuration in which the covering piece 5 is joined to the outer surface of the second sheet 3. The cut line 32 shown in FIG. 19(e) is a cut line having an additional cut line 32e extending toward the opening 3. The cut line 32e is for a second-stage opening operation when it is desired to open the food package 7 further. The score line 32 shown in Figure 19(f) has an additional score line 32f (in the illustrated example, an extension of the second portion 32b and the third portion 32c) extending toward one of the side joint portions 12. The score line 32f is for a second-stage opening operation when it is desired to open the food package 7 from the other side as well. The score line 32 shown in Figure 19(g) has one or more connecting portions 32g. The connecting portions 32g connect the inner and outer regions of the score line 32 with a narrow width of approximately 0.1 mm to 3 mm. This prevents the loose pieces 33 from turning over and causing problems during the production of food packaging bags (particularly when transporting the raw sheet) or during handling.

[0068] In the above embodiment, the cut line 32 and the free piece 33 are formed in the second sheet 3, and the food package 7 is opened at the second sheet 3. However, the present invention is not limited to this. The cut line and the free piece may be formed in the first sheet, and the food package 7 may be opened at the first sheet.

[0069] In the above embodiment, the tearing direction of the sheet is large, so no tearing strip is required, but the present invention does not exclude the use of a tearing strip.

[0070] In the above embodiment, each of the pair of sheets 2 and 3 is divided into a plurality of regions in the first direction, and a plastic sheet, a paper sheet, or a cellophane sheet is selectively used in each region. However, the present invention is not limited to this. For example, at least one of the pair of sheets may be a single sheet that is not divided into a plurality of regions, and a plastic sheet, a paper sheet, or a cellophane sheet may be selectively used.

[0071] In the above embodiment, a plastic sheet, a paper sheet, or a cellophane sheet is selectively used, but the present invention is not limited to this. A nonwoven fabric may also be used as the sheet.

[0072] Furthermore, the header portion is not essential for the food packaging bag. For example, the food packaging bag may have no header portion and may be made up of only the bag body.

[0073] In the above embodiment, the food is a sandwich, but the type of food to be packaged is not particularly limited, and may be Western confectionery such as cake, Japanese confectionery such as castella, bread, or cooked rice foods such as rice balls, as long as the food can be placed in the food packaging bag.

[0074] Furthermore, in the present invention, terms that specify a shape, part, state, or direction, such as "triangular," "right-angled triangular," "trapezoid," "right-angled trapezoid," "rectangular," "rectangular," "center," "straight line," "middle," "end," "side," "coincidence," "identical," "parallel," "orthogonal," "up and down," and "left and right," include not only the thing itself, but also the concept of "approximately" which means something close to or similar to it. [Explanation of symbols]

[0075] 1...food packaging bag, 10...bag body, 11...top joint, 12...side joint, 13...opening, 14...notch, 15...header, 2...first sheet, 2X...first sheet raw material, 20...body, 21...tip, 22A...upper portion, 22B...middle portion, 22C...lower portion, 23...divided sheet, 23X...divided sheet raw material, 24...overlap portion, 25...joining portion, 3...second sheet, 3X...second sheet raw material, 30...body, 31...tip, 32...score line, 32a...first portion, 32b...second portion, 32c...third portion, 32d...end point, 32e...score line, 32f...score line, 32g...connecting portion, 33...free piece, 35A ...upper portion, 35B...middle portion, 35C...lower portion, 36...divided sheet, 36X...original divided sheet, 37...overlapped portion, 38...joint portion, 4...inner sheet, 40...joint portion, 5...covering piece, 5a...grab portion, 50...joint portion, 6...food (sandwich), 7...food package, 8...POS label or food label, L1...mountain fold line of second sheet 3 corresponding to the intersection line between the back and side of the packaged food, L2...mountain fold line of second sheet 3 corresponding to the rear edge of the bottom of the packaged food, L3...valley fold line of second sheet 3 corresponding to the side edge of the bottom of the packaged food, L4...mountain fold line of second sheet 3 to be folded back

Claims

1. A food packaging bag comprising a pair of overlapping sheets each having a shape in which one end side is wider than the other end side in a first direction, the bag body being sealed on three sides by a top joint at one end side and side joints at both sides, and the other end side being an opening, a cut line formed in one sheet of the bag body at a location closer to one of the side joints than the center line in a second direction perpendicular to the first direction, the cut line being formed so that both ends of the cut line approach the opposite side joint and are located on a mountain fold line bent by the side of the packaged food or on the opposite side of the mountain fold line, the cut line serving as a starting point for tearing one sheet to a predetermined width along the second direction toward the opposite side joint; A free piece formed by forming a cut line and having the cut line as an outline; a covering piece that is joined to one of the sheets while covering the cut line from the inner surface side of the one of the sheets, When food is packaged and the food is ready, loose pieces protrude. Food packaging bags.

2. The score line is formed between the inner edge of the top joint and the mountain fold line formed by the bottom surface of the packaged food. The food packaging bag according to claim 1.

3. The cut line comprises a first portion consisting of a line inclined along the side joint, a second portion consisting of a line extending from an end point on the top joint side of the first portion along the second direction, and a third portion consisting of a line extending from an end point on the opening side of the first portion along the second direction longer than the second portion. The food packaging bag according to claim 1 or 2.

4. A middle section including a section where a cut line is formed is defined on one of the sheets, A paper sheet is used in the middle section The food packaging bag according to any one of claims 1 to 3.

5. The covering piece has a sloped hypotenuse along the side joint. The food packaging bag according to any one of claims 1 to 4.

6. The covering piece is joined to one of the sheets at a side joint at the oblique side, and is joined to the other of the sheets at a joint that surrounds the cut line with the side joint as a part. The food packaging bag according to claim 5.

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