Packaging bags

Abstract

To provide a packaging bag which is easy to open and can be opened without damaging cut lines for opening when filling.SOLUTION: Notches 8a served as points to open are formed on the outer edges of a side seal part 8 on both the left and right sides of a packaging bag 101, a first cut line 3 for assisting opening is formed on a front sheet 1A without contacting the notches, a second cut line 4 for assisting opening is formed on a back sheet 1B without contacting the notches, the first and second cut lines have linear parts 3b, 4b and branched parts 3a, 4a branched from both ends of the linear parts, the notch formation ranges on the front and back sheets are located within the widening range of the tips of the branched parts. The position of the linear part of the first cut line on the front sheet and the position of the linear part of the second cut line on the back sheet are not aligned in the up-down direction and the linear parts of the first and second cut lines are parallel to each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] There are known technologies that allow packaging bags (three-sided seal type, four-sided seal type, standing type, etc.) to be torn straight and easily from the notch that triggers the opening. To ensure that the packaging bag tears straight in the cutting direction, for example, straight-cut film is used for the front and back laminated films that make up the packaging bag, or a linear cut line is formed in the outer or middle layer of the laminated film. However, if the tear positions of the front and back laminated films are aligned, it becomes difficult to grasp the openings of each laminated film when removing the contents, making it difficult to open the packaging bag.

[0003] In response to the need to make the opening formed by tearing easier to grip, Patent Document 1 proposes a packaging bag in which a score line is provided in the laminate film to guide the tearing, thereby creating a step between the two laminate films at the opening, making it easier to grip. For example, a first score line is formed in the outer layer of the front side constituting the packaging bag, starting from the outer edge of the left side heat-sealed edge and ending at the outer edge of the right side heat-sealed edge, and a second score line is formed in the outer layer of the back side, starting from the outer edge of the left side heat-sealed edge and ending at the outer edge of the right side heat-sealed edge. Then, by making the positions of the first and second cut lines on the rectangular plane of the laminate film different when the packaging bag is viewed in a plan view, when the upper end of the packaging bag is torn open along the first and second cut lines in the width direction (the direction perpendicular to the heat-sealed portions on the left and right side edges), the outer contour of the cut surface of the laminate film on the front side that forms the tear opening will be different from the outer contour of the cut surface of the laminate film on the back side. This creates a step in the opening, making it easier to open when removing the contents.

[0004] Patent Document 2 also proposes a zippered packaging bag that, by devising the shape and combination of the score lines, can be torn without departing from the score line whether torn toward the front or the back. Zippered packaging bags such as those described in Patent Document 2 are widely used for packaging foods (e.g., confectionery, nuts, etc.), medicines, and supplements (e.g., tablets) due to their convenience of being able to be resealed multiple times with the zipper member even after being opened by tearing the film. However, when re-opening with the zipper member, the front and back laminated films can adhere to each other, making it difficult to open. Especially for elderly people, whose fingers tend to slip, delicate opening tasks can be a burden. Therefore, there is a significant advantage in providing a score line in the laminated film to guide the tear, creating a step between the two laminated films at the opening, making it easier to grip. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-289396 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-96839 Summary of the Invention [Problem to be solved by the invention]

[0006] However, as described in Patent Documents 1 and 2, if a step is created between the two laminated films at the opening to make it easier to grip, the area of ​​the score line becomes large in the vertical direction of the packaging bag, which can make it difficult to fill the contents. For example, when using an automatic filling machine that fills the contents into the packaging bag through an opening with a score line and seals it, if the score line is large, the tool of the filling machine is likely to get caught on the score line and tear the packaging bag. In particular, in the case of packaging bags with zippers, the jaws of the filling machine are inserted inside the zipper member and the zipper member is pushed outward to open the bag, so there is a risk that the packaging bag will tear at the score line when the jaws of the filling machine push the zipper member apart.

[0007] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a packaging bag that is easy to open when removing the contents, and that can be opened without damaging the opening score line when filling the contents. [Means for solving the problem]

[0008] In order to achieve the above object, a packaging bag of a first invention is a packaging bag made by sealing a laminated film so that a storage space for storing contents is formed inside, The laminated film has a front sheet and a back sheet facing the front sheet across the storage space, The sealing portion of the laminated film has side sealing portions formed on both the left and right sides of the packaging bag by the front sheet and the back sheet, An opening start structure that serves as a trigger for opening is formed on the outer edge of at least one of the left and right side seal portions, A first cut line that assists opening is formed in the front sheet so as not to come into contact with the opening start structure, The back sheet is formed so that a second cut line that assists opening does not come into contact with the opening starting structure, the first and second cut lines each have a linear portion and a branched portion branching from at least one end thereof, In each of the front sheet and the back sheet, the formation range of the opening starting structure is located within the spreading range of the tip of the branched shape portion, The position of the linear portion of the first cut line on the front sheet and the position of the linear portion of the second cut line on the back sheet are offset in the vertical direction of the packaging bag, and the linear portions of the first and second cut lines are parallel to each other.

[0009] The packaging bag of the second invention is characterized in that, in the above-mentioned first invention, the tip of the branched-shape portion of the first cut line on the front sheet and the tip of the branched-shape portion of the second cut line on the back sheet are aligned.

[0010] The packaging bag of the third invention is characterized in that, in the above-mentioned second invention, the branched shape portions at the first and second cut lines have a V-shape, and at least one of the branched shape portions has an asymmetrically deformed V-shape.

[0011] The packaging bag of the fourth invention is characterized in that, in any one of the first to third inventions above, the opening start structure is formed on the outer edges of the side seal portions on both the left and right sides, and branched-shaped portions of the first and second cut lines are formed on both ends of the linear-shaped portion.

[0012] The packaging bag of the fifth invention is characterized in that, in any one of the first to fourth inventions, the deviation between the position of the linear portion of the first cut line and the position of the linear portion of the second cut line is 0.5 to 4 mm.

[0013] The packaging bag of a sixth invention is characterized in that, in any one of the first to fifth inventions, the laminated film includes a base material layer and a thermoplastic resin layer.

[0014] The packaging bag of the seventh invention is the packaging bag of the sixth invention, characterized in that it includes at least one intermediate layer between the base material layer and the thermoplastic resin layer.

[0015] The packaging bag of the eighth invention is characterized in that, in the seventh invention, at least one of the first and second cut lines is provided in at least one of the base material layer and the intermediate layer.

[0016] The packaging bag of the ninth invention is characterized in that, in the seventh or eighth invention, at least one of the base material layer, the intermediate layer, and the thermoplastic resin layer has a straight-line cut property that guides linear tearing from one side seal portion to the other side seal portion.

[0017] A packaging bag of the tenth invention is a packaging bag made by sealing a laminated film so that a storage space for storing contents is formed inside, The laminated film has a front sheet and a back sheet facing the front sheet across the storage space, The sealing portion of the laminated film has side sealing portions formed on both the left and right sides of the packaging bag by the front sheet and the back sheet, An opening start structure that serves as a trigger for opening is formed on the outer edge of at least one of the left and right side seal portions, A first cut line that assists opening is formed in the front sheet so as not to come into contact with the opening start structure, The back sheet is formed so that a second cut line that assists opening does not come into contact with the opening starting structure, The first and second cut lines are V-shaped portions having a horizontal V shape, a bending position of the V-shaped portion of the front sheet and a bending position of the V-shaped portion of the back sheet are misaligned in the up-down direction of the packaging bag, In each of the front sheet and the back sheet, the formation range of the opening starting structure is located within the expansion range of the tip of the V-shaped portion, In each of the front sheet and the back sheet, at least one layer constituting the laminated film is characterized by having a straight-line cut property that guides linear tearing from one side seal portion to the other side seal portion.

[0018] The packaging bag of the 11th invention is characterized in that, in any one of the above-mentioned 1st to 10th inventions, it further has a zipper member between the front sheet and the back sheet that allows it to be resealed and reopened, and the zipper member is located on the storage space side of the first and second cut lines.

[0019] The packaging bag of the twelfth invention is characterized in that, in any one of the first to eleventh inventions, the contents are sealed and packaged in a state where they are contained within the containing space. [Effects of the Invention]

[0020] According to the present invention, because the first and second score lines are formed over a small area, the first and second score lines are less likely to become tearing points even when the packaging bag is subjected to force. For example, even when an automatic filling machine is used to fill and seal the contents into the packaging bag through an opening provided with the first and second score lines, the filling machine's tool can be prevented from getting caught on the score lines and tearing the packaging bag. Furthermore, because the opening initiation structure is formed within the expanding range of the tip of the branched-shape portion or V-shaped portion, tearing from the opening initiation structure is reliably guided to each score line. Moreover, misalignment of the first and second score lines causes a misalignment in the tearing position of the front and back laminate films, making it easier to pinch the openings of each laminate film when removing the contents, and thus facilitating opening of the packaging bag. Therefore, a packaging bag can be realized that is easy to open when removing the contents and can be opened without damaging the first and second score lines when filling the contents. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is an external view showing a packaging bag according to a first embodiment. [Figure 2]FIG. 10 is an external view showing a second embodiment of the packaging bag. [Figure 3] FIG. 2 is a cross-sectional view taken along line L1-L1′ in FIG. [Figure 4] 2(A) and 2(B) are cross-sectional views taken along lines L2-L2' and L3-L3' in FIG. [Figure 5] A plan view showing an opening that has been torn apart by guides along the first and second cut lines, creating a step. [Figure 6] FIG. 3 is a plan view showing specific examples of first and second cut lines used in the first embodiment. [Figure 7] FIG. 10 is a plan view showing specific examples of first and second cut lines used in the second embodiment. [Figure 8] FIG. 2 is a plan view showing packaging bags according to Examples 1 to 4 and Comparative Examples 1 to 4. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, packaging bags, packaging products, etc. according to embodiments of the present invention will be described with reference to the drawings. Note that identical or corresponding parts among the embodiments and specific examples will be designated by the same reference numerals, and redundant explanations will be omitted where appropriate.

[0023] FIG. 1 shows a schematic structure of a packaging bag 101 and a packaged product 201 according to a first embodiment, and FIG. 3 shows a schematic cross-sectional structure of the packaging bag 101. FIG. 2 shows a schematic structure of a packaging bag 102 and a packaged product 202 according to a second embodiment, and FIG. 4 shows a schematic cross-sectional structure of the packaging bag 102. In FIGS. 1 and 2, (A) is a plan view showing the standing-type packaging bags 101, 102 in a folded state, and (B) is a front view showing the packaged products 201, 202 (packaged food, etc.) in which contents F (food, etc.) are sealed in the packaging bags 101, 102. FIG. 3 is a cross-sectional view taken along line L1-L1' in FIG. 1(A), FIG. 4(A) is a cross-sectional view taken along line L2-L2' in FIG. 2(A), and FIG. 4(B) is a cross-sectional view taken along line L3-L3' in FIG. 2(A).

[0024] The packaging bags 101, 102 are made of three sheets of packaging material: a front sheet 1A, a back sheet 1B, and a bottom sheet 1C (FIGS. 1 and 2), all of which are made of laminated film (FIGS. 3 and 4). The packaging bags 101, 102 are made into stand-up pouches by heat-sealing the laminated film so that a storage space 7 for storing contents F is formed inside the packaging bags 101, 102. Therefore, they can be manufactured using a general stand-up pouch manufacturing machine, and the heat-sealing is performed in a continuous bag manufacturing machine that produces actual products, under sealing temperature conditions that do not impair the properties and functions of the product. The packaging bags 101, 102 are not limited to stand-up pouches, and may be flat pouches (three-side seal type, four-side seal type, etc.), etc.

[0025] The front sheet 1A and the back sheet 1B are arranged opposite each other with a storage space 7 interposed therebetween, and the left and right edges of the sheets are heat-sealed while they are overlapped. A bottom sheet 1C, which forms a two-fold gusset portion between the front sheet 1A and the back sheet 1B, is heat-sealed to the lower edges of the front sheet 1A and the back sheet 1B at the respective edges. However, the upper edges of the front sheet 1A and the back sheet 1B are left unsealed (FIGS. 3 and 4). In other words, in the packaging bags 101 and 102 (FIGS. 1 and 2(A)), the storage space 7 is formed by a side seal portion 8 formed by heat sealing the front sheet 1A and the back sheet 1B together, and a gusset seal portion 9 formed by heat sealing the front sheet 1A and the back sheet 1B together with the bottom sheet 1C, and an opening 10h is formed above the storage space 7.

[0026] 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 through the opening 10h into the storage space 7 of the packaging bags 101, 102, in which the side seal portion 8 and the gusset seal portion 9 have been formed, the head seal portion 10 (FIGS. 1 and 2(B)) is formed by heat sealing the front sheet 1A and the back sheet 1B, thereby obtaining packaged products 201, 202 that are hermetically packaged with the contents F contained in the storage space 7.

[0027] As shown in Figures 3 and 4, the laminate film (front sheet 1A, back sheet 1B, and bottom sheet 1C) constituting the packaging bags 101, 102 is composed of a base material layer 11 as an outer layer, a sealant layer (thermoplastic resin layer) 13 as an inner layer, and an intermediate layer 12 (aluminum layer, printing ink layer, adhesive layer, etc.) provided therebetween. In other words, the laminate film has a laminate structure including the base material layer 11, the intermediate layer 12, and the sealant layer 13 from the outside to the inside of the packaging bag. As described above, the laminate film may have a laminate structure of three or more layers, but may also have a laminate structure of two layers, consisting of the base material layer 11 and the sealant layer 13. Note that examples of methods for laminating the layers in the laminate film include sandwich lamination and dry lamination.

[0028] Since the base layer 11 is required to have the strength to protect the contents F, the strength as a printing base material to withstand the load of the printing work, and the ease of tearing the laminated film when opening, it is preferable to use a synthetic resin film with excellent mechanical, physical, and chemical properties. From this perspective, 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 with oxygen barrier properties, polypropylene-based films such as biaxially oriented polypropylene (OPP) film, and polyethylene-based films such as biaxially oriented polyethylene (OPE) film.

[0029] The properties of the functional film used for the base layer 11 include barrier properties, puncture resistance, and straight-cutting properties. Specific examples of functional films include transparent vapor-deposited films that have barrier properties already imparted, and straight-cut films that have straight-cutting properties. Straight-cut films have straight-cutting properties that guide linear tearing in a predetermined cutting direction, and the packaging bag 102 (FIG. 2, etc.) is torn straight from one side seal portion 8 to the other side seal portion 8 due to the straight-cutting properties of the base layer 11 described below. The thickness of the film constituting the base layer 11 can be selected as appropriate, but is preferably about 12 to 25 μm.

[0030] The material of the intermediate layer 12 can be appropriately selected depending on the physical properties (barrier properties, puncture resistance, etc.) required for the packaging bags 101, 102. Specific examples include an aluminum layer, a printed ink layer, an adhesive layer, etc. The aluminum layer constituting the intermediate layer 12 may be, for example, a barrier layer made of annealed aluminum foil, preferably having a thickness of approximately 6 to 15 μm. Aluminum-deposited PET film or aluminum-deposited ONY film may also be used. The printed ink layer constituting the intermediate layer 12 may be, for example, a white ink layer, a pattern layer, or other colored ink layer. The adhesive layer constituting the intermediate layer 12 may be, for example, a layer made of a dry lamination adhesive commonly used in the dry lamination method. From the perspective 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.), or the straight-cut film described above.

[0031] The sealant layer 13 is provided to bond two laminated films together to form the storage space 7 and to seal the contents F. The bonding is performed by bringing the sealant layers 13 into contact with each other and heating them. For example, the bonding can be performed by dry laminating or extrusion laminating the base layer 11 or the intermediate layer 12. Therefore, when the bags are made, the sealant layer 13 is located on the innermost side of the packaging bags 101, 102 (FIGS. 3 and 4). The sealant layer 13 may be any layer formed from a thermo-adhesive resin that can be melted by heat and welded to each other, and therefore, the sealant layer 13 can be appropriately selected according to the physical properties required for the packaging bags 101, 102. For example, a layer having the straight cut property described above may be used.

[0032] Specific examples of the sealant layer 13 include polyethylene-based films (PE films) such as linear low-density polyethylene (LLDPE) film and low-density polyethylene (LDPE) film, and polypropylene-based films (PP films) such as non-oriented polypropylene (CPP) film. The thickness of the film constituting the sealant layer 13 can be determined appropriately taking into consideration the required physical properties (heat sealability), cost, etc., but is preferably about 10 to 100 μm, and particularly about 40 to 60 μm.

[0033] A specific example of the schematic laminate structure (base layer 11 / intermediate layer 12 / sealant layer 13) of the laminated film (front sheet 1A, back sheet 1B, bottom sheet 1C) is as follows: PET12 / printing ink, ALM7 / PE40, VMPET12 / printing ink / PE50, PET12 / printing ink, ALM7, straight cut PET12 / PE40, PET12 / printing ink, ALM7, straight cut OPP20 / PE40, PET12 / ALM7 / LDPE60, PET12 / ALM7 / LLDPE60, PET12 / ALM7, PET12 / LLDPE60, OPP20 / PET12,ALM7 / LLDPE60, Special ONY15 / ALM7 / LLDPE60, Examples include:

[0034] however, PET12: Polyethylene terephthalate film, thickness 12 μm, ALM7: Aluminum foil, thickness 7 μm, PE40, PE50: Polyethylene film, thickness 40, 50 μm, VMPET12: Transparent vapor-deposited polyethylene terephthalate, thickness 12 μm, Straight cut PET12: Stretched PET film with straight cut properties, thickness 12 μm, Straight cut OPP20: Straight cut stretched polypropylene film, thickness 20 μm, LDPE60: Low density polyethylene film, thickness 60 μm, LLDPE60: Linear low-density polyethylene film, thickness 60 μm, OPP20: Biaxially oriented polypropylene film, thickness 20 μm, Special ONY15: Biaxially oriented nylon with oxygen barrier properties, thickness 15 μm, is.

[0035] An opening structure and a resealing structure are provided at the top of the packaging bags 101, 102. As shown in Figures 1 and 2, the opening structure is composed of a first cut line 3, a second cut line 4, a notch 8a, etc., and the resealing structure is composed of a zipper member 2 made of a thermoplastic resin. When opening, the laminated film (front sheet 1A, back sheet 1B) is torn apart starting from notches 8a provided on the outer edges of the side seal portions 8 on both the left and right sides, and is guided by the first and second cut lines 3, 4. In other words, the notches 8a act as a trigger for opening, the first cut line 3 assists in opening in the front sheet 1A, and the second cut line 4 assists in opening in the back sheet 1B.

[0036] Because the opening structure is located between the head seal portion 10 and the zipper member 2 (FIGS. 1 and 2(B)), when the packaged product 201 is opened using the opening structure, the portion including the head seal portion 10 is cut off, making it possible to open and close (reseal and reseal) the packaging bags 101, 102 using the zipper member 2 (zipper function). Figure 5 shows an opening 10h that has been torn (in the direction of arrow ma) by the guides of the first and second cut lines 3, 4, creating a step 5.

[0037] Since the zipper member 2 is provided closer to the center of the packaging bags 101, 102 than the opening structure, the storage space 7 becomes smaller when the opening structure is used for the initial opening, and some contents F may become easily caught when being removed. Therefore, if resealing and reopening of the packaging bags 101, 102 is not required, the zipper member 2 may be omitted.

[0038] As shown in Figures 3 and 4, the zipper member 2 is provided between the front sheet 1A and the back sheet 1B. It is composed of a concave stripe member 2a provided in the sealant layer 13 of the front sheet 1A and a convex stripe member 2b provided in the sealant layer 13 of the back sheet 1B, and the concave stripe member 2a and the convex stripe member 2b are fitted together to enable attachment and detachment. The concave stripe member 2a and the convex stripe member 2b are formed across the entire width in the left-right direction from one side seal portion 8 to the other side seal portion 8 (Figures 1 and 2). The interlocking of the concave stripe member 2a and the convex stripe member 2b enables the packaging bag 101, 102 to be resealed (reseal function). Therefore, the packaging bag 101, 102 can be easily resealed without using adhesive tape, clips, or the like, which prevents moisture and dust from entering the storage space 7 and allows the remaining contents F to be hygienically stored.

[0039] The concave members 2a may be provided in the sealant layer 13 of the back sheet 1B, and the convex members 2b may be provided in the sealant layer 13 of the front sheet 1A. In other words, the arrangement of the concave members 2a and the convex members 2b is not limited to that shown in Figures 3 and 4, and the zipper member 2 may be formed by a concave member 2a provided in the sealant layer 13 of one of the front sheet 1A and the back sheet 1B, and a convex member 2b provided in the sealant layer 13 of the other.

[0040] The concave stripe members 2a and convex stripe members 2b are fixed to the front sheet 1A and back sheet 1B by heat sealing with each sealant layer 13. For example, a long rolled zip closure member 2 is unwound and sandwiched between the front sheet 1A and back sheet 1B at a predetermined position, and then heat sealed with a heat seal bar. By feeding the zip closure 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 an insulating plate is interposed between the concave stripe member 2a and the convex stripe member 2b, thermal fusion between the concave stripe member 2a and the convex stripe member 2b can be prevented, and the front sheet 1A and back sheet 1B can be heat sealed to the zip closure member 2 simultaneously and continuously.

[0041] The home plate-shaped notches 8a (Figs. 1 and 2) that constitute the opening structure are formed as opening initiation structures at the upper portions of the left and right side seal portions 8, at the outer edges of both the left and right ends, to serve as opening starting points (i.e., opening triggers). 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 and a position that does not reach the inner edge). In addition, because the left and right notches 8a are formed to penetrate both the front sheet 1A and the back sheet 1B, their positions in the vertical direction of the packaging bags 101, 102 (the distance from the opening 10h or the outer edge of the head seal portion 10) are the same.

[0042] The shape of the notch 8a is not limited to the home plate shape, but may be a V-shape (V notch), a U-shape (U notch), a linear shape (I notch), a polygonal shape, etc. The notch 8a used here is a UV notch (base notch) that is a home plate shape made by combining a U-shape and a V-shape, and this shape has the advantages of being highly visible and easy to find its position by touch. Also, to prevent it from getting caught during transportation, an MP notch made up of fine scratches may be used as the notch 8a.

[0043] The orientation of the notch 8a is preferably set so that the tear direction from the notch 8a coincides with the linear easy tear direction of the laminate film (front sheet 1A, back sheet 1B) (for example, the linear cuttability of the sealant layer 13). In the packaging bag 102 (Fig. 2, etc.), the linear cuttability described below is utilized in the base material layer 11, but the linear cuttability is also effective in the packaging bag 101 (Fig. 1, etc.). In addition, a marking such as a cut or opening may be provided at the location where the notch 8a is formed so that consumers can easily identify 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.

[0044] The first and second score lines 3, 4 that form the opening structure are half-cut lines formed on the surface of the laminate film (front sheet 1A, back sheet 1B) to a depth that does not penetrate the thickness direction, and as shown in Figures 3 and 4, 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. The first and second score lines 3, 4 are both formed by full cuts in the base material layer 11, but they may also be formed by half-cuts in the base material layer 11. The first and second score lines 3, 4 may also be formed in the intermediate layer 12, and in that case, it is possible to obtain the same effect as when they are formed in the base material layer 11.

[0045] The first and second score lines 3, 4 are preferably formed by laser cutting using a pulsed laser or the like (laser tear guide). Examples of lasers used for the laser cutting include carbon dioxide lasers, YAG lasers, semiconductor lasers, and argon ion lasers. The first and second score lines 3, 4 may also be formed mechanically using a die roll or the like.

[0046] In the packaging bag 101 (FIG. 1), first and second cut lines 3, 4 are formed in the front sheet 1A and the back sheet 1B, respectively, from one side seal portion 8 to the other side seal portion 8. The first and second cut lines 3, 4 have linear portions 3b, 4b and branched portions (V-shaped portions) 3a, 4a branching off from both ends, resulting in a continuous and symmetrical shape overall. In other words, the linear portions 3b, 4b have branched portions 3a, 4a that have a sideways V-shape (a so-called bird's foot shape) formed at both ends (the bending positions of the V-shaped portions on both the left and right sides are connected horizontally by the linear portions 3b, 4b).

[0047] In contrast, in the packaging bag 102 (Fig. 2), there is an area between the front sheet 1A and the back sheet 1B between the left and right side seal portions 8 where the first and second cut lines 3, 4 are not formed. In other words, the first and second cut lines 3, 4 each consist of two parts separated to the left and right, with left and right linear parts 3b, 4b and branched parts 3a, 4a branching off from the end on one side (the notch 8a side) of the linear parts 3b, 4b.

[0048] As described above, in the packaging bags 101, 102 (FIGS. 1 and 2), the first cut line 3 on the front sheet 1A that assists in opening has a straight portion 3b and a branched portion 3a that branches off from at least one end of the straight portion 3b, and the second cut line 4 on the back sheet 1B that assists in opening has a straight portion 4b and a branched portion 4a that branches off from at least one end of the straight portion 4b. The first and second cut lines 3, 4 are formed so as not to contact the notch 8a, and the range in which the notch 8a is formed on each of the front sheet 1A and the back sheet 1B is located within the expansion range of the tips of the branched portions 3a, 4a. In other words, the branched portions 3a, 4a are formed so as to surround the notch 8a from one side.

[0049] The position of the linear portion 3b of the first cut line 3 on the front sheet 1A and the position of the linear portion 4b of the second cut line 4 on the back sheet 1B are misaligned in the vertical direction of the packaging bags 101, 102 (mismatch in linear shapes), and the linear portions 3b, 4b of the first and second cut lines 3, 4 are parallel to each other. For example, the misalignment between the linear portion 3b of the first cut line 3 and the linear portion 4b of the second cut line 4 is 0.5 to 4 mm. In the specific examples (FIGS. 6 and 7) described below, this misalignment is d1 = 1 mm or d2 = 2 mm.

[0050] Although the relative positions of the linear portions 3b, 4b to the front and back sheets 1A, 1B are shifted as described above, the tip of the branched portion 3a at the first cut line 3 on the front sheet 1A coincides with the tip of the branched portion 4a at the second cut line 4 on the back sheet 1B. In other words, the spreading ranges (i.e., tear openings) of the tips of the branched portions 3a, 4a coincide. This is because the branched portion 3a has a symmetrical V-shape, while the branched portion 4a has an asymmetrically deformed V-shape (V-shape mismatch). By making the branched portion 4a asymmetrically deformed, the bending position of the branched portion 4a on the back sheet 1B can be shifted in the vertical direction of the packaging bag 101, 102 by the same amount as the relative positional shift of the linear portions 3b, 4b. Therefore, it is possible to maintain the branched state of the branched portion 4a from the linear portion 4b so that the range in which the notch 8a is formed is located within the range in which the tips of the branched portions 3a and 4a expand.

[0051] Opening of the packaged product 201 begins when the upper portion of one side seal 8 (e.g., the portion overlapping the head seal 10) is pinched and the front sheet 1A and back sheet 1B are torn from the notch 8a in the side seal 8 toward the branched portions 3a and 4a. The first and second cut lines 3 and 4 are formed so as not to contact the notch 8a, and the area where the notch 8a is formed is located within the expansion range of the tips of the branched portions 3a and 4a. Therefore, the tear from the notch 8a is first received by the branched portions 3a and 4a and then guided to the next linear portions 3b and 4b. The front sheet 1A and back sheet 1B are then simultaneously torn, guided by the first and second cut lines 3 and 4. Finally, the portion including the head seal 10 is cut off, and the packaging bags 101 and 102 are in the opened state shown in FIG. 5.

[0052] In packaging bag 101 (Fig. 1), tearing of front and back sheets 1A, 1B is guided in the order of branched-shaped portions 3a, 4a, linear-shaped portions 3b, 4b, and branched-shaped portions 3a, 4a. In contrast, in packaging bag 102 (Fig. 2), base material layer 11 is made of a straight-cut film, so tearing of front and back sheets 1A, 1B is guided in the order of branched-shaped portions 3a, 4a, linear-shaped portions 3b, 4b, straight-cut property of base material layer 11, linear-shaped portions 3b, 4b, and branched-shaped portions 3a, 4a.

[0053] In the packaging bag 102 (FIG. 2), the straight-cutting property of the base material layer 11 guides linear tearing of the packaging bag 102 in the left-right direction, so it is acceptable for there to be an area between the left and right side seal portions 8 where the first and second cut lines 3, 4 are not formed. Also, a layer other than the base material layer 11 may have straight-cutting property. In other words, it is sufficient that at least one layer among the base material layer 11, intermediate layer 12, and sealant layer 13 has straight-cutting property that guides linear tearing from one side seal portion 8 to the other side seal portion 8.

[0054] When filling the packaging bags 101, 102 (FIGS. 1 and 2) with contents F through the opening 10h, the claws of a filling machine are inserted into the inside of the zipper member 2 through the opening 10h, and when the zipper member 2 is pushed open from the inside to the outside to open it, a large force is applied to the central portions of the front and back sheets 1A, 1B. If the range of the first and second cut lines 3, 4 is large (for example, if the bag has an oval-shaped portion), the claws of the filling machine are likely to catch on the first and second cut lines 3, 4 and tear the bag. Therefore, it is preferable to make the range of the first and second cut lines 3, 4 as small as possible in the central portions of the front and back sheets 1A, 1B to make the front and back sheets 1A, 1B less likely to tear.

[0055] From the above viewpoint, in the packaging bags 101, 102, the first and second cut lines 3, 4 have straight-line portions 3b, 4b and branched-line portions 3a, 4a branching from at least one end thereof, and the straight-line portions 3b, 4b are offset and arranged parallel to each other, so that the range in which the first and second cut lines 3, 4 are formed can be minimized in the vertical direction (filling suitability).In the packaging bag 102, the first and second cut lines 3, 4 are not formed between the left and right side seal portions 8 (the central part of the packaging bag 102), so that the first and second cut lines 3, 4 are hardly damaged when filling the contents F.

[0056] In the packaging bags 101, 102, the linear portions 3b, 4b reliably create a step 5 (bag cuttability), and the step 5 can be pinched with the fingertips to easily open the opening (bag openability). Therefore, not only can the packaged products 201, 202 be initially opened by tearing the laminated film, but also when re-opening the packaging bag 101 that has been resealed with the zipper member 2, easy opening is possible. As a result, the contents F can be easily and quickly removed from the packaging bag 101.

[0057] Furthermore, in the packaging bags 101, 102, by making the branched-shape portion 4a asymmetrically deformed, the range in which the notch 8a is formed is located within the range in which the tip of the branched-shape portion 3a, 4a expands, making it possible to reliably guide the tear from the notch 8a to the branched-shape portion 3a, 4a (bag cuttability). As a result, the linear-shaped portions 3b, 4b can be enlarged close to the notch 8a, making it possible to enlarge the range in which the step 5 is formed in the left-right direction. At positions close to the notch 8a, the linear-shaped portions 3b, 4b are less damaged when filling the bag with the contents F (filling suitability), and the large step 5 in the left-right direction makes it even easier to open the bag (bag openability).

[0058] Fig. 6 shows a specific example of the first and second cut lines 3, 4 used in the first embodiment, and Fig. 7 shows a specific example of the first and second cut lines 3, 4 used in the second embodiment. In Figs. 6 and 7, the sizes of each part are indicated by d1 = 1 mm, d2 = 2 mm, d3 = 3 mm, and d4 = 4 mm. Considering the use of the packaging bags 101, 102 according to the contents F (food, etc.), for example, if the size of the packaging bags 101, 102 is 156 mm in length (vertical direction) × 120 mm in width (horizontal direction), the horizontal sizes of the first and second cut lines 3, 4 are 4 mm for the branched-shaped portions 3a, 4a and 107 mm for the linear-shaped portion 3b, and the vertical size of the branched-shaped portions 3a, 4a is 4 mm.

[0059] Fig. 6(A) shows the first and second cut lines 3, 4 used in the packaging bag 101 (Fig. 1), and Fig. 7(A) shows the first and second cut lines 3, 4 used in the packaging bag 102 (Fig. 2). In the first and second cut lines 3, 4 shown in Fig. 6(A) and Fig. 7(A), the linear portions 4b are shifted upward from the linear portions 3b, so that the step 5 (Fig. 5) is formed, exposing the inner surface of the backsheet 1B. In contrast, in the first and second cut lines 3, 4 shown in Fig. 6(B) and Fig. 7(B), the linear portions 4b are shifted downward from the linear portions 3b, so that the step 5 (Fig. 5) is formed, exposing the inner surface of the frontsheet 1A.

[0060] In the first and second cut lines 3, 4 shown in Figures 6(A) and 7(A), the branched-shaped portion 3a has a symmetrical V-shape, and the branched-shaped portion 4a has an asymmetrically deformed V-shape. In contrast, in the first and second cut lines 3, 4 shown in Figures 6(C) and 7(C), both branched-shaped portions 3a, 4a have asymmetrically deformed V-shapes. In other words, the first and second cut lines 3, 4 shown in Figures 6(C) and 7(C) use the same first cut line 3 as the second cut line 4 shown in Figures 6(B) and 7(B) in the first and second cut lines 3, 4 shown in Figures 6(A) and 7(A). Therefore, the amount of positional misalignment of the linear-shaped portions 3b, 4b is d1 × 2 = d2 = 2 mm.

[0061] 6 and 7(A) to 7(C), the branched portions 3a, 4a have a V-shape at the first and second cut lines 3, 4, and at least one of the branched portions 3a, 4a has an asymmetrically deformed V-shape. With this configuration, if the formation range of the notch 8a is positioned within the expansion range of the tip of the branched portions 3a, 4a, it becomes possible to reliably guide the tear from the notch 8a to the branched portions 3a, 4a (bag cuttability).

[0062] In the first and second cut lines 3, 4 shown in Figures 6(A) and 7(A), the branch-shaped portions 3a have a symmetrical V-shape, while the branch-shaped portions 4a have an asymmetrically deformed V-shape. In contrast, in the first and second cut lines 3, 4 shown in Figures 6(D) and 7(D), both branch-shaped portions 3a, 4a have a symmetrical V-shape. That is, in the first and second cut lines 3, 4 shown in Figures 6(D) and 7(D), the second cut line 4, which has the same shape as the first cut line 3, is arranged parallel to the first cut line 3 in the first and second cut lines 3, 4 shown in Figures 6(A) and 7(A). Therefore, the tip of the branch-shaped portion 3a of the first cut line 3 on the front sheet 1A does not coincide with the tip of the branch-shaped portion 4a of the second cut line 4 on the back sheet 1B. However, if the formation range of the notch 8a is positioned within the common expansion range of the tips of the branched-shape portions 3a and 4a, it is possible to reliably guide the tear from the notch 8a to the branched-shape portions 3a and 4a (bag cutting ability).

[0063] The first and second cut lines 3, 4 shown in Fig. 7(E) are the first and second cut lines 3, 4 shown in Fig. 7(A) with the linear portions 3b, 4b omitted. That is, the first and second cut lines 3, 4 consist only of branched portions (V-shaped portions) 3a, 4a having a horizontal V shape. As with the first and second cut lines 3, 4 shown in Fig. 7(A) and other figures, the bending position of the branched portion 3a in the front sheet 1A and the bending position of the branched portion 4a in the back sheet 1B are offset in the vertical direction of the packaging bags 101, 102. Furthermore, in each of the front and back sheets 1A, 1B, the formation range of the notches 8a is located within the spreading range of the tips of the V-shaped portions 3a, 4a (Fig. 2 and other figures). Therefore, as mentioned above, in each of the front and back sheets 1A and 1B, at least one layer constituting the laminated film has straight-line cutting properties, making it possible to guide linear tearing from one side seal portion 8 to the other side seal portion 8.

[0064] As explained above, because the ranges at which the first and second score lines 3, 4 are formed are small, the first and second score lines 3, 4 are unlikely to become tearing points even when force is applied to the packaging bags 101, 102. For example, even when an automatic filling machine is used to fill and hermetically seal the packaging bags 101, 102 with contents F through the opening 10h at which the first and second score lines 3, 4 are formed, it is possible to prevent the jig of the filling machine from getting caught on the score lines 3, 4 and tearing the packaging bags 101, 102 (filling suitability). Furthermore, because the ranges at which the notches 8a, 18a are formed are located within the ranges at which the tips of the branched-shape portions (or V-shaped portions) 3a, 4a expand, tearing from the notches 8a, 18a is reliably guided to the score lines 3, 4 (bag cuttability). Furthermore, since the misalignment of the first and second cut lines 3, 4 causes a misalignment in the tearing positions of the front and back laminate films, it becomes easier to pinch the openings 10h of the laminate films when removing the contents F, making it easier to open the packaging bags 101, 102 (bag openability). Therefore, it is possible to realize packaging bags 101, 102 that are easy to open when removing the contents F and that can be opened without damaging the first and second cut lines 3, 4 for opening when filling the contents F.

[0065] As described above, the packaging bags 101, 102 have excellent manufacturability and also have excellent properties such as ease of removal of the contents F and ease of resealing and reopening after opening, and therefore can be made low cost yet highly usable. Note that the opening structure and resealing structure described above are not limited to the standing type packaging bags 101, 102, but can also be applied to other types of packaging bags (four-side seal type, three-side seal type, etc.), and the same effects as those described above can be obtained. [Example]

[0066] Packaging bags embodying the present invention will be described in more detail below. Packaging bags E1 and E2 (FIGS. 8(A) and (B)) of Examples 1 to 4 (EX1 to 4) and packaging bags C1 and C2 (FIGS. 8(C) and (D)) of Comparative Examples 1 to 4 (CX1 to 4) are flat pouches of a three-sided seal type, produced by heat-sealing a front sheet 1A and a back sheet 1B together, with side seal portions 18 and a bottom seal portion 19 formed as heat-sealed portions. V-shaped notches 18a are formed in the side seal portions 18 on both the left and right sides of packaging bags E1, E2, C1, and C2 as opening initiation structures. Similar to packaging bags 101 and 102 (FIGS. 1 and 2), zipper members 2 are provided between the first and second cut lines 3 and 4 and the storage space 7 (near the center of the packaging bag below the first and second cut lines 3 and 4).

[0067] The packaging bag E1 (FIG. 8(A)) of Examples 1 and 2 (EX1 and 2) has first and second cut lines 3 and 4 formed therein similar to the packaging bag 101 (FIG. 1), and the packaging bag E2 (FIG. 8(B)) of Examples 3 and 4 (EX3 and 4) has first and second cut lines 3 and 4 formed therein similar to the packaging bag 102 (FIG. 2). Also, the packaging bag C1 (FIG. 8(C)) of Comparative Examples 1 and 2 (CX1 and 2) has first and second cut lines 3 and 4 formed in a straight line that are aligned in the front sheet 1A and the back sheet 1B so as to connect the notches 18a on both the left and right sides. In the packaging bag C2 (Figure 8(D)) of comparative examples 3 and 4 (CX3, 4), a first cut line 3 consisting of an oval-shaped portion and straight-line portions connecting both the left and right sides of the oval-shaped portion to the notch 18a is formed in the front sheet 1A, and a straight second cut line 4 connecting both the left and right notches 18a is formed in the back sheet 1B.

[0068] Example 1 (EX1), FIG. 8(A) The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are PET 12μm / printing ink / adhesive / aluminum foil 7μm / adhesive / PE film 40μm. The first and second cut lines 3, 4 of packaging bag E1 were processed on the PET surface using a CO2 laser so that the amount of positional deviation in the vertical direction of packaging bag E1 was 1mm.

[0069] Example 2 (EX2), FIG. 8(A) The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are transparent vapor-deposited PET 12 μm / printing ink / adhesive / PE film 50 μm. The first and second cut lines 3 and 4 of packaging bag E1 were processed on the PET surface using a die roll so that the amount of positional deviation in the vertical direction of packaging bag E1 was 1 mm.

[0070] Example 3 (EX3), FIG. 8(B) The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are PET 12μm / printing ink / adhesive / aluminum foil 7μm / adhesive / straight-cut PET 12μm / adhesive / PE film 40μm. The first and second cut lines 3, 4 of packaging bag E2 were processed on the PET surface using a CO2 laser so that the amount of positional deviation in the vertical direction of packaging bag E2 was 1mm.

[0071] Example 4 (EX4), FIG. 8(B) The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are PET 12μm / printing ink / adhesive / aluminum foil 7μm / adhesive / straight-cut OPP 20μm / adhesive / PE film 40μm. The first and second cut lines 3, 4 of packaging bag E2 were processed on the PET surface using a CO2 laser so that the amount of positional deviation in the vertical direction of packaging bag E2 was 1mm.

[0072] <Comparative Example 1 (CX1), FIG. 8(C)> The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are PET 12μm / printing ink / adhesive / aluminum foil 7μm / adhesive / PE film 40μm. The first and second cut lines 3, 4 of packaging bag C1 were processed on the PET surface using a CO2 laser.

[0073] Comparative Example 2 (CX2), FIG. 8(C) The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are transparent vapor-deposited PET 12 μm / printing ink / adhesive / PE film 50 μm. The first and second cut lines 3 and 4 of the packaging bag C1 were processed on the PET surface using a die roll.

[0074] Comparative Example 3 (CX3), FIG. 8(D) The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are PET 12μm / printing ink / adhesive / aluminum foil 7μm / adhesive / straight-cut PET 12μm / adhesive / PE film 40μm. The first and second cut lines 3 and 4 of packaging bag C2 were processed on the PET surface using a CO2 laser.

[0075] <Comparative Example 4 (CX4), FIG. 8(D)> The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are PET 12μm / printing ink / adhesive / aluminum foil 7μm / adhesive / straight-cut OPP 20μm / adhesive / PE film 40μm. The first and second cut lines 3 and 4 of packaging bag C2 were processed on the PET surface using a CO2 laser.

[0076] Table 1 shows the evaluation results for filling suitability, bag cuttability, and bag openability of Examples 1 to 4 (EX1 to 4) and Comparative Examples 1 to 4 (CX1 to 4). Regarding filling suitability, the following criteria were used: ◎: no tearing of the packaging bag (tears from the cut line) during filling, ○: almost no tearing of the packaging bag (tears from the cut line) during filling, ×: some tearing of the packaging bag (tears from the cut line) during filling; regarding bag cuttability, the following criteria were used: ◎: no tearing away from the predetermined position (tears away from the cut line), ○: almost no tearing away from the predetermined position (tears away from the cut line), ×: some tearing away from the predetermined position (tears away from the cut line); and regarding bag openability, ◎: the opening was very easy to grip, ○: the opening was easy to grip, ×: the opening was difficult to grip.

[0077] [Table 1] [Explanation of symbols]

[0078] 1A Front sheet (laminated film) 1B Back sheet (laminated film) 1C Bottom sheet (laminated film) 2 Chuck member 2a Concave member 2b Convex member 3 First cut line 3a Branch shaped part (V shaped part) 3b Straight line part 4 Second cut line 4a Branch shaped part (V shaped part) 4b Straight line part 5 steps 7. Containment Space 8 Side seal part 8a Notch (opening start structure) 9 Gusset seal 10 Head seal 10h opening 11 Base material layer 12 Middle Class 13 Sealant layer (thermoplastic resin layer) 18 Side seal part 18a notch (opening start structure) 19 Bottom seal part 101,102,E1,E2,C1,C2 Packaging bag 201,202 Packaging products F Contents

Claims

1. A packaging bag made by sealing a laminated film so that a storage space for storing contents is formed inside, The laminated film has a front sheet and a back sheet facing the front sheet across the storage space, The sealing portion of the laminated film has side sealing portions formed on both the left and right sides of the packaging bag by the front sheet and the back sheet, An opening start structure that serves as a trigger for opening is formed on the outer edge of each of the left and right side seal portions, a first cut line that assists opening in the front sheet is formed so as not to come into contact with the opening initiation structure; a second cut line that assists opening on the back sheet is formed so as not to come into contact with the opening starting structure; the first and second cut lines each comprise a linear portion and a V-shaped branch portion branching from both ends thereof, In each of the front sheet and the back sheet, the formation range of the opening starting structure is located within the spreading range of the tip of the branched shape portion, A packaging bag characterized in that the position of the linear portion of the first cut line on the front sheet and the position of the linear portion of the second cut line on the back sheet are offset in the vertical direction of the packaging bag, and the linear portions of the first and second cut lines are parallel to each other.

2. 2. The packaging bag according to claim 1, wherein a tip of the branched portion of the first cut line in the front sheet coincides with a tip of the branched portion of the second cut line in the back sheet.

3. 3. The packaging bag according to claim 2, wherein at least one of the first and second cut lines has a branched shape that is asymmetrically deformed into a V shape.

4. The packaging bag according to any one of claims 1 to 3, characterized in that the deviation between the position of the linear portion of the first cut line and the position of the linear portion of the second cut line is 0.5 to 4 mm.

5. The packaging bag according to any one of claims 1 to 4, wherein the laminated film comprises a base material layer and a thermoplastic resin layer.

6. 6. The packaging bag according to claim 5, further comprising at least one intermediate layer between the base material layer and the thermoplastic resin layer.

7. 7. The packaging bag according to claim 6, wherein at least one of the first and second score lines is provided in at least one of the base layer and the intermediate layer.

8. The packaging bag according to claim 6 or 7, characterized in that at least one of the base material layer, the intermediate layer and the thermoplastic resin layer has a straight-line cut property that guides a straight tear from one side seal portion to the other side seal portion.

9. A packaging bag made by sealing a laminated film so that a storage space for storing contents is formed inside, The laminated film has a front sheet and a back sheet facing the front sheet across the storage space, The sealing portion of the laminated film has side sealing portions formed on both the left and right sides of the packaging bag by the front sheet and the back sheet, An opening start structure that serves as a trigger for opening is formed on the outer edge of at least one of the left and right side seal portions, a first cut line that assists opening in the front sheet is formed so as not to come into contact with the opening initiation structure; a second cut line that assists opening on the back sheet is formed so as not to come into contact with the opening starting structure; The first and second cut lines are V-shaped portions having a horizontal V-shape, a bending position of the V-shaped portion of the front sheet and a bending position of the V-shaped portion of the back sheet are misaligned in the up-down direction of the packaging bag, In each of the front sheet and the back sheet, the formation range of the opening start structure is located within the expansion range of the tip of the V-shaped portion, A packaging bag characterized in that at least one layer constituting the laminated film in each of the front sheet and the back sheet has a straight-line cut property that guides linear tearing from one side seal portion to the other side seal portion.

10. The packaging bag according to any one of claims 1 to 9, further comprising a zipper member between the front sheet and the back sheet that enables resealing and re-opening, the zipper member being located on the storage space side of the first and second cut lines.

11. The packaging bag according to any one of claims 1 to 10, wherein the contents are sealed and packaged in a state where they are contained in the storage space.

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