Packaging bag and its manufacturing method

Abstract

To provide a packaging bad capable of opening a chuck member without damaging a cutting line for opening in filling with a content, and a manufacturing method of the same.SOLUTION: A storage space 7 storing a content F is formed by heat seal of a front surface sheet 1A and a back surface sheet 1B including a base material layer, an intermediate layer and a sealant layer inside of a packaging bag 101. The packaging bag 101 has side seal parts 8 formed at both the left and right sides with the front surface sheet 1A and the back surface sheet 1B as a seal part formed by heat seal. First and second cutting lines 3, 4 are formed from one side seal part 8 to the other side seal part 8 on each base material layer, and the first and second cutting lines 3, 4 are formed more shallowly at a center area than side areas at both the left and right sides. A chuck member 2 is situated on the side of the storage space 7 of the first and second cutting lines 3, 4 between the front surface sheet 1A and the back surface sheet 1B.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging bag and a manufacturing method thereof, and more particularly to a packaging bag having a resealable function, such as a pouch with a zipper, and a manufacturing method thereof. [Background technology]

[0002] Zipper pouches are widely used for packaging foods (sweets, snacks, nuts, topping sugar, etc.), medicines (tablets, etc.), supplements, etc., because they can be resealed and stored many times using the zipper member even after being opened by tearing the film. However, when reopening with the zipper member, the two films may adhere to each other, making it difficult to open. In particular, elderly people have slippery fingers, which makes it difficult to open the pouch with fine details, so there is a need for an opening that is easy to grasp. In order to meet such needs, Patent Documents 1 to 3 propose packaging bags in which a step is created between the two films at the opening by providing a cut line in the film to guide the tear, making it easier to grasp. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5561107 [Patent Document 2] Patent No. 6346504 [Patent Document 3] Patent No. 6087014 Summary of the Invention [Problem to be solved by the invention]

[0004] The score lines as described in Patent Documents 1 to 3 can be easily formed by laser cutting. In addition, since the score lines and zipper members are provided at the top of the packaging bag, it is common to fill the contents from the bottom in packaging bags of four-sided seal type and the like. However, since a gusset portion is formed at the bottom in a standing type packaging bag, it is difficult to fill the contents from the bottom or side. This results in a reduction in the storage space, an increase in the size of the packaging bag, and a complicated manufacturing process. Therefore, in a standing type packaging bag, the contents are filled from the top, and even in other types of packaging bags, it is necessary to fill the contents from the top depending on the manufacturing process, etc.

[0005] When filling a packaging bag from the top, the jaws of the filling machine are inserted inside the zipper member and the zipper member is pushed outward to open the bag. For example, if a film is made up of three layers, an outer layer, an aluminum layer, and an inner layer, and the outer layer is completely cut by laser cutting to form a score line, the packaging bag may tear at the score line when the jaws of the filling machine push the zipper member apart. If the laser intensity is weakened to make the score line shallow, it becomes difficult to open the bag by tearing the film, and there is a risk that the film may tear at a position other than the score line. If the score line is formed at a position where the jaws of the filling machine do not hit, the packaging bag will become larger.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a packaging bag and a manufacturing method thereof that enable the zipper member to be opened without damaging the score line for opening when filling the contents. [Means for solving the problem]

[0007] In order to achieve the above object, a packaging bag according to a first aspect of the present invention is a packaging bag having a storage space for storing contents formed on the inside thereof by heat sealing a laminated film including a base layer, an intermediate layer, and a sealant layer, The laminated film has a front sheet and a back sheet facing the front sheet across the storage space, A zipper member is provided between the front sheet and the back sheet, The seal portion formed by the heat seal includes a side seal portion formed on both the left and right sides of the front sheet and the back sheet, A first score line is formed in the base material layer of the front sheet from one side seal portion to the other side seal portion, A second score line is formed in the base material layer of the back sheet from one side seal portion to the other side seal portion, The first score line and the second score line are formed shallower in the center region than in the left and right side regions, The chuck member is located on the accommodation space side of the first score line and the second score line.

[0008] The packaging bag of the second invention is the packaging bag of the first invention, wherein the first cut line is formed by fully cutting the base material layer of the front sheet in the side region and half-cutting the base material layer in the center region, The second cut line is formed by cutting the entire side area and half-cutting the center area in the base material layer of the back sheet.

[0009] The packaging bag of the third invention is the packaging bag of the first or second invention, wherein the first cut line is composed of horizontal V-shaped portions formed in the side seal portions on both the left and right sides, an oval-shaped portion, and linear portions respectively connecting the left and right sides of the oval-shaped portions to the V-shaped portions, The second cut line is composed of horizontal V-shaped portions formed in the side seal portions on both the left and right sides and a linear portion connecting the V-shaped portions, The first score line in the center region is formed by at least a part of the oval-shaped portion, The second cut line in the center region is formed of at least a part of the linear portion, The present invention is characterized in that the V-shaped portion and the linear portion are positioned so as to overlap in the vertical direction at the first score line and the second score line.

[0010] The packaging bag of the fourth invention is characterized in that, in any one of the first to third inventions above, the zipper member is composed of a concave stripe member provided in one sealant layer of the front sheet and the back sheet, and a convex stripe member provided in the other sealant layer, and the bag is resealed by interlocking between the concave stripe member and the convex stripe member.

[0011] The packaging bag of the fifth invention is a standing-type packaging bag in any one of the first to fourth inventions above, characterized in that the laminated film further includes a bottom sheet that forms a two-fold gusset portion between the front sheet and the back sheet.

[0012] The packaging bag of a sixth invention is any one of the first to fifth inventions, characterized in that the content is hermetically packaged in a state where it is contained within the containing space.

[0013] The manufacturing method of the seventh invention is a manufacturing method of the packaging bag according to any one of the first to sixth inventions, The first score line and the second score line are formed by laser cutting.

[0014] The manufacturing method of the eighth invention is characterized in that, in the seventh invention, the output of the laser cutting process is adjusted to be smaller in the center region than in the side regions on both the left and right sides, so that the first cutting line and the second cutting line are formed shallower in the center region than in the side regions on both the left and right sides.

[0015] The manufacturing method of the 9th invention is characterized in that, in the above-mentioned 7th or 8th invention, the number of scannings in the laser cutting process is adjusted to be less in the center region than in the side regions on both the left and right sides, so that the first cutting line and the second cutting line are formed shallower in the center region than in the side regions on both the left and right sides. Effect of the Invention

[0016] According to the present invention, the first and second cut lines are shallower in the center region than in the left and right side regions, so that the first and second cut lines in the center region are less likely to become the starting point for tearing when the packaging bag is subjected to force than the first and second cut lines in the side regions. For example, when the jaws of a filling machine are inserted inside the packaging bag to push the zipper member open, a large force is applied to the first and second cut lines in the center region, but tearing of the packaging bag is suppressed in the center region where the first and second cut lines are shallow. Therefore, when filling the contents, it is possible to open the zipper member without damaging the first and second cut lines for opening. [Brief description of the drawings]

[0017] [Figure 1] 1 is an external view showing an embodiment of a packaging bag and a packaged product. [Diagram 2] 2A is a cross-sectional view showing the L1-L1' line cross-section, the L2-L2' line cross-section, and the L3-L3' line cross-section of FIG. [Diagram 3] FIG. 4 is a plan view for explaining the formation of first and second score lines by laser cutting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, packaging bags, packaging products, etc. according to embodiments of the present invention will be described with reference to the drawings. Note that the same or corresponding parts in each embodiment, specific example, etc. are designated by the same reference numerals, and duplicated explanations will be omitted as appropriate.

[0019] Fig. 1 shows a schematic diagram of the overall structure of a packaging bag 101 and a packaged product 201 according to an embodiment, and Fig. 2 shows a schematic diagram of a cross-sectional structure of the packaging bag 101. In Fig. 1, (A) is a plan view showing a standing-type packaging bag 101 in a folded state, and (B) is a front view showing a packaged product 201 (packaged food, etc.) in which contents F (food, etc.) are sealed in the packaging bag 101. In Fig. 2, (A) is a cross-sectional view taken along line L1-L1' in Fig. 1(A), (B) is a cross-sectional view taken along line L2-L2' in Fig. 1(A), and (C) is a cross-sectional view taken along line L3-L3' in Fig. 1(A).

[0020] The packaging bag 101 is composed of three packaging materials, a front sheet 1A, a back sheet 1B, and a bottom sheet 1C (FIG. 1), all of which are made of laminated films (FIG. 2). The laminated films are heat sealed (thermal bonding) to form a standing pouch inside the packaging bag 101, so that a storage space 7 for storing contents F is formed inside the packaging bag 101. Therefore, it can be manufactured using a general standing pouch bag manufacturing machine, and the heat sealing is performed under sealing temperature conditions within a range that does not impair the properties and functions of the product when the bag is manufactured using a continuous bag manufacturing machine that manufactures actual products.

[0021] The front sheet 1A and the back sheet 1B are arranged to face each other with a storage space 7 in between, and the left and right edges of the sheets are heat-sealed in a superimposed state. The bottom sheet 1C, which forms a gusset part folded in half between the front sheet 1A and the back sheet 1B, is heat-sealed at the edges of the bottom sheet 1C to the lower ends of the front sheet 1A and the back sheet 1B. However, the upper ends of the front sheet 1A and the back sheet 1B are left unsealed (FIG. 2). In other words, in the packaging bag 101 (FIG. 1(A)), the storage space 7 is formed by the side seal part 8 formed by heat sealing the front sheet 1A and the back sheet 1B, and the gusset seal part 9 formed by heat sealing the front sheet 1A and the back sheet 1B to the bottom sheet 1C, and an opening 10h is formed above the storage space 7.

[0022] The opening 10h is used as a filling port for the contents F (food, cosmetics, detergent, medicine, supplements, etc.; form: liquid, gel, solid, powder, etc.). After the contents F are filled into the storage space 7 of the packaging bag 101 in which the side seal portion 8 and the gusset seal portion 9 are formed, the head seal portion 10 (FIG. 1(B)) is formed by heat sealing the front sheet 1A and the back sheet 1B, and a packaged product 201 is obtained in which the contents F are sealed and packaged in the storage space 7.

[0023] The laminated film (front sheet 1A, back sheet 1B, and bottom sheet 1C) constituting the packaging bag 101 is composed of a base material layer 11 as an outer layer, a sealant layer 13 as an inner layer, and an intermediate layer 12 (aluminum layer, printed ink layer, adhesive layer, etc.) provided therebetween, as shown in Fig. 2. In other words, the laminated film has a laminated structure including the base material layer 11, intermediate layer 12, and sealant layer 13 from the outside to the inside of the packaging bag. Note that examples of the method for laminating the layers in the laminated film include a sandwich lamination method and a dry lamination method.

[0024] The base layer 11 is required to have the strength to protect the contents F, the strength to withstand the load of printing work, and the ease of tearing the laminated film when opening, so it is preferable to use a synthetic resin film having excellent mechanical, physical, and chemical properties. From this viewpoint, specific examples of the base layer 11 include polyester-based films such as polyethylene terephthalate (PET) film and transparent vapor-deposited polyethylene terephthalate (VMPET) film, polyamide-based films such as biaxially oriented nylon (ONY) film and special ONY film having oxygen barrier properties, and polypropylene-based films such as biaxially oriented polypropylene (OPP) film. The thickness of the film constituting the base layer 11 is preferably about 12 to 25 μm.

[0025] Specific examples of the intermediate layer 12 include an aluminum layer, a printed ink layer, and an adhesive layer. An example of the aluminum layer constituting the intermediate layer 12 is a barrier layer made of annealed aluminum foil, and the thickness thereof is preferably about 6 to 15 μm. An example of the printed ink layer constituting the intermediate layer 12 is a layer made of colored ink such as a white ink layer or a pattern layer. An example of the adhesive layer constituting the intermediate layer 12 is a layer made of a dry lamination adhesive that is generally used in the dry lamination method. From the viewpoint of protecting the contents F, the intermediate layer 12 may be a film layer similar to that of the base layer 11 (a polyester film such as a PET film, etc.).

[0026] The sealant layer (thermoadhesive resin layer) 13 is provided to bond two laminated films together to form the storage space 7 and seal the contents F. The bonding is performed by bringing the sealant layers 13 into contact with each other and heating them. Therefore, when the bag is made, the sealant layer 13 is located on the innermost side of the packaging bag 101 (FIG. 2). The sealant layer 13 may be any layer formed of a thermoadhesive resin that can be melted by heat and welded to each other, so the sealant layer 13 can be appropriately selected according to the physical properties required for the packaging bag 101.

[0027] Specific examples of the sealant layer 13 include polyethylene-based films such as linear low-density polyethylene (LLDPE) film and low-density polyethylene (LDPE) film, and polypropylene-based films such as non-oriented polypropylene (CPP) film. The thickness of the film constituting the sealant layer 13 can be appropriately determined in consideration of the required physical properties (heat sealability), costs, etc., but is preferably about 10 to 100 μm, particularly about 15 to 50 μm.

[0028] A specific example of the schematic laminate structure (base layer 11 / middle layer 12 / sealant layer 13) of the laminated film (front sheet 1A, back sheet 1B, bottom sheet 1C) is as follows: PET12 / ALM7 / LDPE60 PET12 / ALM7, PET12 / LLDPE60 OPP20 / PET12,ALM7 / LLDPE60 Special ONY15 / ALM7 / LLDPE60 Examples include:

[0029] however, PET12: Polyethylene terephthalate (PET) film, thickness 12 μm, ALM7: Aluminum foil, thickness 7 μm, LDPE60: Low density polyethylene film, thickness 60μm, LLDPE60: Linear low density polyethylene film, thickness 60μm, OPP20: Biaxially oriented polypropylene film, thickness 20 μm, Special ONY15: Biaxially oriented nylon with oxygen barrier properties, thickness 15μm, It is.

[0030] An opening structure and a resealing structure are provided at the top of the packaging bag 101. As shown in Fig. 1, the opening structure is composed of a first cut line 3, a second cut line 4, and a notch 8a, and the resealing structure is composed of a zipper member 2 made of a thermoplastic resin. When the laminated film (front sheet 1A, back sheet 1B) is opened, the tearing is guided by the first and second cut lines 3 and 4 starting from the notch 8a. Since this opening structure is located between the head seal portion 10 and the zipper member 2, when the packaged product 201 is opened using the opening structure, the portion including the head seal portion 10 is cut off, and the packaging bag 101 can be opened and closed (resealed and reopened) by the zipper member 2 (zipper function).

[0031] As shown in Fig. 2, the zipper member 2 is composed of a concave member 2a provided on the sealant layer 13 of the front sheet 1A and a convex member 2b provided on the sealant layer 13 of the back sheet 1B, and can be attached and detached by fitting the concave member 2a and the convex member 2b. The concave member 2a and the convex member 2b are formed over the entire left-right direction from one side seal portion 8 to the other side seal portion 8 (Fig. 1), so that the concave member 2a and the convex member 2b can be engaged to reseal the packaging bag 101 (resealing function). Therefore, the packaging bag 101 can be easily resealed without using adhesive tape, clips, etc., so that the intrusion of moisture and dust into the storage space 7 can be suppressed and the remaining contents F can be hygienically stored.

[0032] The concave member 2a may be provided in the sealant layer 13 of the back sheet 1B, and the convex member 2b may be provided in the sealant layer 13 of the front sheet 1A. In other words, the zipper member 2 may be composed of the concave member 2a provided in the sealant layer 13 of one of the front sheet 1A and the back sheet 1B, and the convex member 2b provided in the sealant layer 13 of the other.

[0033] The concave stripe member 2a and the convex stripe member 2b are fixed to the front sheet 1A and the back sheet 1B by heat sealing with each sealant layer 13. For example, a long chuck member 2 wound in a roll is unwound, sandwiched at a predetermined position between the front sheet 1A and the back sheet 1B, and heat sealed with a heat seal bar. By supplying the chuck member 2 in accordance with the arrangement of the heat seal bar, the concave stripe member 2a can be heat sealed to the front sheet 1A, and the convex stripe member 2b can be heat sealed to the back sheet 1B. If a heat insulating plate is interposed between the concave stripe member 2a and the convex stripe member 2b, it is possible to prevent the concave stripe member 2a and the convex stripe member 2b from thermally fusing, and it becomes possible to heat seal the chuck member 2 to the front sheet 1A and the back sheet 1B simultaneously and continuously.

[0034] The horizontal V-shaped notches 8a (FIG. 1) constituting the opening structure are formed in the upper part of the left and right side seal portions 8 at the outer edges of both the left and right ends so as to become starting points for opening. However, the formation range of the notches 8a is limited to within the formation range of the side seal portions 8 (between the outer edges of the left and right side seal portions 8 to a position not reaching the inner edge). In addition, the left and right notches 8a are formed so as to penetrate the front sheet 1A and the back sheet 1B together, so that their positions in the vertical direction of the packaging bag 101 (the distance from the opening 10h or the outer edge of the head seal portion 10) are the same.

[0035] The shape of the notch 8a is not limited to a V-shape, and may be a U-shape, a polygonal shape, a linear shape, etc., and the orientation of the notch 8a is preferably set so that the breaking direction from the notch 8a coincides with the linear easy tearing direction of the laminated film (front sheet 1A, back sheet 1B) (for example, the linear cuttability of the sealant layer 13). In addition, a mark such as a cut or opening may be provided at the location where the notch 8a is formed so that consumers can easily recognize the opening position. The marking can be applied by gravure printing or the like when forming a printing ink layer as the intermediate layer 12.

[0036] The first and second score lines 3, 4 constituting the opening structure are half-cut lines formed on the surface of the laminate film (front sheet 1A, back sheet 1B) at a depth that does not penetrate in the thickness direction, and as shown in Fig. 2, the first score line 3 is formed in the base material layer 11 of the front sheet 1A, and the second score line 4 is formed in the base material layer 11 of the back sheet 1B. Also, as shown in Fig. 1, the first and second score lines 3, 4 are both formed from one side seal portion 8 to the other side seal portion 8, and have a continuous and bilaterally symmetrical shape overall.

[0037] FIG. 3(A) shows the first cut line 3, and FIG. 3(B) shows the second cut line 4. As shown in FIG. 3(A), the first cut line 3 is made up of a horizontal V-shaped portion 3a formed in the left and right side seal portions 8 (FIG. 1), an oval-shaped portion 3c, and a linear portion 3b connecting the left and right sides of the oval-shaped portion 3c to the V-shaped portion 3a. As shown in FIG. 3(B), the second cut line 4 is made up of a horizontal V-shaped portion 4a formed in the left and right side seal portions 8 (FIG. 1), and a linear portion 4b connecting the V-shaped portions 4a. Since the V-shaped portions 3a and 4a are formed to surround the notch 8a (FIG. 1), tearing from the notch 8a is first received by the V-shaped portions 3a and 4a, and is then guided by the first and second cut lines 3 and 4.

[0038] The center region RC in Fig. 3 is a region located at the center of the opening 10h (Fig. 1(A)), and is a region where a large force is applied to the first and second cut lines 3, 4 when, for example, in filling the packaging bag 101 with the contents F through the opening 10h, the jaws of a filling machine are inserted into the inside of the zipper member 2 through the opening 10h, and the zipper member 2 is pushed open from the inside to the outside to open the bag. In contrast, the side regions RS located on both the left and right sides of the center region RC are regions where force is applied to the first and second cut lines 3, 4 to tear the front sheet 1A and the back sheet 1B from the notch 8a when opening the packaged product 201. For example, the first cut line 3 is a region from the V-shaped portion 3a at the end, which affects opening, to the R portion (branch portion) of the oval-shaped portion 3c. Therefore, in the center region RC, it is preferable to make the first and second cut lines 3, 4 shallow so that the front sheet 1A and the back sheet 1B are less likely to tear, and in the side regions RS, it is preferable to make the first and second cut lines 3, 4 deep so that the front sheet 1A and the back sheet 1B are more likely to tear.

[0039] From the above viewpoint, the first cutting line 3 in the center region RC is made up of a part of the oval-shaped portion 3c, and the second cutting line 4 in the center region RC is made up of a part of the straight-line-shaped portion 4b. The first cutting line 3 and the second cutting line 4 are positioned so that the V-shaped portions 3a, 4a and the straight-line-shaped portions 3b, 4b overlap in the vertical direction. Note that the first cutting line 3 in the center region RC is made up of the entire oval-shaped portion 3c, and the second cutting line 4 in the center region RC is made up of a part of the straight-line-shaped portion 4b. part That is, the first cutting line 3 in the center region RC may be set to be made up of at least a part of the oval-shaped portion 3c, and the second cutting line 4 in the center region RC may be set to be made up of at least a part of the straight-line-shaped portion 4b.

[0040] Considering the use of the packaging bag 101 according to the contents F (food, etc.), for example, if the size of the packaging bag 101 is length (up-down direction): 160 mm × width (left-right direction): 120 mm, the center region RC is 50 mm, and the side region RS is 35 mm. Also, the horizontal sizes of the first and second cut lines 3, 4 are as follows: V-shaped portions 3a, 4a: 5 mm, linear portion 3b: 5 mm, oval portion 3c: 100 mm, linear portion 4b: 110 mm, and the vertical size of oval portion 3c is 6 mm.

[0041] 2, the first and second cut lines 3, 4 are formed shallower in the center region RC than in the side regions RS on both the left and right sides. That is, the first cut line 3 is completely cut in the base material layer 11 of the front sheet 1A in the side regions RS and half cut in the center region RC. Also, the second cut line 4 is completely cut in the base material layer 11 of the back sheet 1B in the side regions RS and half cut in the center region RC.

[0042] Since the depths of the first and second score lines 3, 4 are different between the center region RC and the side region RS as described above (half-cut control), it is preferable to form the first and second score lines 3, 4 by laser cutting using a pulsed laser or the like. Examples of lasers used in the laser cutting include a carbon dioxide laser, a YAG laser, a semiconductor laser, and an argon ion laser.

[0043] To form the first and second cut lines 3, 4 by laser cutting so that each base material layer 11 of the front sheet 1A and the back sheet 1B is fully cut in the side region RS and half cut in the center region RC, it is preferable to half-cut each base material layer 11 by weak laser processing (center region RC: weak laser processing region) and fully cut each base material layer 11 by strong laser processing (side region RS: strong laser processing region). The method of changing the laser processing intensity in this way is as follows: (1) A method of forming the first cut line 3 and the second cut line 4 shallower in the center region RC than in the left and right side regions RS by adjusting the output of the laser cutting process to be smaller in the center region RC than in the left and right side regions RS (output adjustment); (2) A method of forming the first cutting line 3 and the second cutting line 4 shallower in the center region RC than in the side regions RS on both the left and right sides by adjusting the number of scannings in the laser cutting process to be less in the center region RC than in the side regions RS on both the left and right sides (adjusting the number of scannings).

[0044] Method (1) may not be compatible with some laser processing equipment due to software issues. Also, steps may occur due to overlapping laser processing in areas where the output has been changed. In contrast, method (2) is compatible with a wide variety of laser processing equipment and is easy to adjust. Another advantage is that it can be set with reference to the current conditions (e.g., irradiation time (or scan speed) x output (%)). When using method (2), it is preferable to set the number of scans for laser cutting processing to, for example, 1 time for the center region RC and 2 to 3 times for the side regions RS.

[0045] An example of forming the first and second score lines 3, 4 (an example of laser cutting processing by method (2)) when the number of scanning times is set to one in the center region RC and two in the side region RS will be described below. When forming the first score line 3, in Fig. 3(A), laser scanning is performed in the order of positions A1, A2, A3, A4, A3, A5, A3, A2, A6, A2, A1, A7, A8, A9, A10, A9, A11, A9, A8, A12, A6, A12, A8, A7. However, during laser scanning from position A12 to position A6 or from position A6 to position A12, laser light irradiation is turned off. When forming the second cutting line 4, in FIG. 3(B), the laser scans in the order of positions B1, B2, B3, B2, B4, B2, B1, B5, B6, B7, B6, B8, B6, and B5.

[0046] By performing the above-mentioned laser scanning, each base material layer 11 of the front sheet 1A and the back sheet 1B can be fully cut (scanned twice) in the side region RS and half cut (scanned once) in the center region RC. Since aluminum foil easily blocks laser light, when an aluminum layer is provided as the intermediate layer 12, each base material layer 11 can be easily fully cut by strong laser processing.

[0047] The opening of the packaged product 201 begins when the upper part of one side seal portion 8 (for example, the overlapping portion with the head seal portion 10) is pinched and the front sheet 1A and the back sheet 1B are torn from the notch 8a of the side seal portion 8 toward the V-shaped portions 3a, 4a (FIG. 3). The tear from the notch 8a is first received by the V-shaped portions 3a, 4a, and the tear of the front sheet 1A and the back sheet 1B proceeds simultaneously while being guided by the first and second cut lines 3, 4. In other words, the tear of the front sheet 1A is guided in the order of the V-shaped portion 3a, the straight-line portion 3b, the oval-shaped portion 3c, the straight-line portion 3b, and the V-shaped portion 3a, while the tear of the back sheet 1B is guided in the order of the V-shaped portion 4a, the straight-line portion 4b, and the V-shaped portion 4a.

[0048] When the force applied to the front sheet 1A and the back sheet 1B by the tearing is directed toward the front sheet 1A (when pulled all the way to the front), when the tearing of the front sheet 1A reaches position A2 (FIG. 3(A)), the front sheet 1A tends to tear along the lower side of the oval-shaped portion 3c (curve including positions A6 and A12). When the force applied to the front sheet 1A and the back sheet 1B by the tearing is directed toward the back sheet 1B (when pushed all the way to the rear), when the tearing of the front sheet 1A reaches position A2 (FIG. 3(A)), the front sheet 1A tends to tear along the upper side of the oval-shaped portion 3c (curve including positions A1 and A7). In either case, the back sheet 1B is torn along the linear portion 4b.

[0049] The upper end portion (FIG. 1(B)) of the packaging bag 101 including the head seal portion 10 is cut along the first and second cut lines 3 and 4 as described above, so that an opening opening consisting of smooth curves and straight lines is formed. At the opening opening, a step is certainly generated between the curved outer edge (upper or lower outer edge of the oval-shaped portion 3c) of the cut surface of the front sheet 1A torn along the oval-shaped portion 3c of the first cut line 3 and the straight outer edge of the cut surface of the back sheet 1B torn along the straight-shaped portion 4b of the second cut line 4, so that the opening opening can be easily opened by pinching the step with fingertips (easy opening function). Therefore, not only when the packaged product 201 is first opened by tearing the laminated film, but also when the packaging bag 101 resealed by the zipper member 2 is reopened, easy opening is possible. As a result, the content F can be easily and quickly taken out from the packaging bag 101.

[0050] As described above, the first and second cut lines 3, 4 are formed shallower in the center region RC than in the side regions RS on both the left and right sides, so that the first and second cut lines 3, 4 in the center region RC are less likely to become the starting point of tearing when the packaging bag 101 is subjected to force than the first and second cut lines 3, 4 in the side regions RS. For example, when the jaws of a filling machine are inserted inside the packaging bag 101 to push and open the zipper member 2, a large force is applied to the first and second cut lines 3, 4 in the center region RC, but tearing of the packaging bag 101 is suppressed in the center region RC where the first and second cut lines 3, 4 are shallow. Therefore, when filling the contents F, it is possible to open the zipper member 2 without damaging the first and second cut lines 3, 4 for opening.

[0051] As described above, packaging bag 101 has excellent manufacturability and excellent properties such as ease of removal of content F and ease of resealing and reopening after opening, and therefore can achieve high usability at low cost. Note that the above-mentioned opening structure and resealing structure are not limited to standing type packaging bag 101, but can also be applied to other types of packaging bags (four-sided seal type, three-sided seal type, etc.), and the same effects as those described above can be obtained. [Explanation of symbols]

[0052] 1A Front sheet (laminated film) 1B Back sheet (laminated film) 1C Bottom sheet (laminated film, gusset section) 2 Chuck member 2a Concave member 2b Convex member 3 First cut line 3a V-shaped part 3b Straight line part 3c Oval shaped part 4 Second cut line 4a V-shaped part 4b Straight line part RC Center area (weak laser processing area) RS side area (strong laser processing area) 7. Containment Space 8 Side seal section (heat seal section) 8a notch 9 Gusset seal part (heat seal part) 10 Head seal section (heat seal section) 10h opening 11 Base material layer 12 Middle Class 13 Sealant layer 101 Packaging bags 201 Packaging products F Contents

Claims

1. A packaging bag having a storage space for storing contents formed on the inside by heat sealing a laminated film including a base layer, an intermediate layer, and a sealant layer, The laminated film has a front sheet and a back sheet facing the front sheet across the storage space, A zipper member is provided between the front sheet and the back sheet, The seal portion formed by the heat seal includes a side seal portion formed on both the left and right sides of the front sheet and the back sheet, A first score line is formed in the base material layer of the front sheet from one side seal portion to the other side seal portion, a second score line is formed in the base material layer of the back sheet from one side seal portion to the other side seal portion; The first score line and the second score line are formed shallower in the center region than in the left and right side regions, the chuck member is located on the accommodation space side of the first score line and the second score line, the first score line has an oval shaped portion; A packaging bag, wherein the first cut line in the center region comprises the entire oval-shaped portion.

2. The first cut line is formed by fully cutting the base material layer of the front sheet in the side region and half-cutting the base material layer in the center region, 2. The packaging bag according to claim 1, wherein the second cut line is formed by cutting the base material layer of the back sheet completely in the side regions and half-cutting the base material layer in the center region.

3. The packaging bag according to claim 1 or 2, characterized in that the zipper member is constituted by a concave stripe member provided in one sealant layer of the front sheet and the back sheet, and a convex stripe member provided in the other sealant layer, and the packaging bag is resealed by interlocking of the concave stripe member and the convex stripe member.

4. The packaging bag according to any one of claims 1 to 3, characterized in that the packaging bag is a standing type, and the laminated film further includes a bottom sheet that forms a two-fold gusset portion between the front sheet and the back sheet.

5. 5. The packaging bag according to claim 1, wherein the content is sealed and packaged in a state where it is contained within the storage space.

6. A method for producing the packaging bag according to any one of claims 1 to 5, A manufacturing method comprising forming the first score line and the second score line by laser cutting.

7. 7. The manufacturing method according to claim 6, characterized in that the output of the laser cutting process is adjusted to be smaller in the center region than in the side regions on both the left and right sides, so that the first score line and the second score line are formed shallower in the center region than in the side regions on both the left and right sides.

8. The manufacturing method according to claim 6 or 7, characterized in that the number of scannings in the laser cutting process is adjusted to be less in the center region than in the side regions on both the left and right sides, so that the first cut line and the second cut line are formed shallower in the center region than in the side regions on both the left and right sides.

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