JP7771623B2 - packaging bag - Google Patents

Description

The present invention relates to packaging bags, for example, packaging bags with a resealable function, such as a zipper pouch.

Technology is known that allows packaging bags (three-sided sealed, four-sided sealed, standing type, etc.) to be torn straight and easily from a notch that triggers 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.

To meet the need for an opening formed by tearing that is easier to grip, Patent Document 1 proposes a packaging bag in which a score line is provided in the laminate film to guide the tear, creating a step between the two laminate films at the opening, making it easier to grip. For example, a first score line is provided in the outer layer of the front side of 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 provided 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. Furthermore, by making the first and second cut lines partially different positions on the rectangular plane of the laminate film when the packaging bag is viewed in a plan view, when the top end of the packaging bag is torn open along the first and second cut lines in the width direction (the direction perpendicular to the left and right side edge heat-sealed portions), the outer contours of the cut surfaces of the front and back laminate film that form the tear opening will be different. This creates a step in the opening, making it easier to open when removing the contents.

Patent Document 2 proposes a zippered packaging bag that, by devising the shape and combination of the score lines, can be torn either toward the front or the back without straying from the score line. Zippered packaging bags like those described in Patent Document 2 are widely used for packaging foods (confectionery, nuts, etc.), medicines, and supplements (tablets, etc.) due to their convenience of being able to be resealed multiple times with the zipper member for storage even after being opened by tearing the film. However, when resealing with the zipper member, the front and back laminated films can adhere to each other, making it difficult to open. Elderly people, in particular, have slippery fingers, which can make delicate opening tasks a burden. Therefore, there are significant benefits to 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.

Japanese Patent Application Laid-Open No. 2005-289396 JP 2012-96839 A

However, as described in Patent Documents 1 and 2, creating a step between the two laminated films at the opening to make it easier to grip results in a larger area of the score line in the vertical direction of the packaging bag, which can make filling the contents difficult. For example, when using an automatic filling machine that fills the contents into the packaging bag through an opening with a score line and then seals it, if the score line is large, there is a high possibility that the tool of the filling machine will 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.

The present invention was made in light of these 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 when filling the contents.

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 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 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.

The packaging bag of the second invention is the same as the packaging bag of the first invention, characterized in that the tip of the branched-shape portion of the first cut line on the front sheet coincides with the tip of the branched-shape portion of the second cut line on the back sheet.

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

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

The packaging bag of the fifth invention is any one of the first to fourth inventions, 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.

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

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

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

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

A packaging bag according to a tenth aspect of the present invention is a packaging bag produced by sealing a laminated film so that a storage space for storing contents is formed inside the bag,
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,
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.

The packaging bag of the eleventh invention is any one of the first to tenth inventions, further comprising a zipper member between the front sheet and the back sheet that allows the bag to be resealed and reopened, and the zipper member is located on the storage space side of the first and second cut lines.

The packaging bag of the twelfth invention is characterized in that, in any one of the first to eleventh inventions above, the contents are sealed and packaged in a state where they are contained within the storage space.

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 with the first and second score lines, the filling machine's tool can be prevented from catching 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 or V-shaped portion, tearing from the opening initiation structure is reliably guided to each score line. Furthermore, because misalignment of the first and second score lines causes a difference in the tearing position of the front and back laminate films, the openings of each laminate film are easier to grasp when removing the contents, making it easier to open 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 used for opening when filling the contents.

1 is an external view showing a first embodiment of a packaging bag; FIG. 10 is an external view showing a second embodiment of a packaging bag. A cross-sectional view showing the L1-L1' line cross section of Figure 1(A). 2A is a cross-sectional view showing the L2-L2' line cross section and the L3-L3' line cross section of FIG. FIG. 10 is a plan view showing an opening that has been torn apart by guides along the first and second cut lines, creating a step. FIG. 4 is a plan view showing specific examples of first and second cut lines used in the first embodiment. FIG. 10 is a plan view showing specific examples of first and second cut lines used in the second embodiment. 1A to 1C are plan views showing packaging bags according to Examples 1 to 4 and Comparative Examples 1 to 4.

Packaging bags, packaging products, and the like according to embodiments of the present invention will be described below with reference to the drawings. Note that identical or corresponding parts between the various embodiments and specific examples will be designated by the same reference numerals, and duplicate explanations will be omitted where appropriate.

1 shows a schematic diagram of the overall structure of a packaging bag 101 and a packaged product 201 according to a first embodiment, and FIG. 3 shows a schematic diagram of the cross-sectional structure of the packaging bag 101. FIG. 2 shows a schematic diagram of the overall structure of a packaging bag 102 and a packaged product 202 according to a second embodiment, and FIG. 4 shows a schematic diagram of the 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).

Packaging bags 101, 102 are composed of three sheets of packaging material: front sheet 1A, back sheet 1B, and bottom sheet 1C (Figs. 1 and 2), all of which are made of laminated film (Figs. 3 and 4). They are then heat-sealed (thermally bonded) to form a standing pouch, creating a storage space 7 for contents F inside packaging bags 101, 102. Therefore, they can be manufactured using a standard standing pouch manufacturing machine, and heat sealing is performed using a continuous bag manufacturing machine used to manufacture actual products, under sealing temperature conditions that do not impair the product's properties and functionality. Note that packaging bags 101, 102 are not limited to standing pouches; they may also be flat pouches (three-sided seal type, four-sided seal type, etc.).

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

Opening 10h is used as a filling port for contents F (food, cosmetics, detergent, medicine, supplements, etc.; form: liquid, gel, solid, powder, etc.). After contents F are filled through opening 10h into storage space 7 of packaging bags 101, 102, which have side seals 8 and gusset seals 9, head seal 10 (Figures 1 and 2(B)) is formed by heat sealing front sheet 1A and back sheet 1B, resulting in packaged products 201, 202 sealed and packaged with contents F contained within storage space 7.

As shown in Figures 3 and 4, the laminate film (front sheet 1A, back sheet 1B, and bottom sheet 1C) that makes up packaging bags 101 and 102 is composed of a substrate 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.) disposed therebetween. In other words, the laminate film has a laminate structure that includes the substrate layer 11, intermediate layer 12, and sealant layer 13 from the outside to the inside of the packaging bag. While the laminate film may have a laminate structure of three or more layers, it may also have a two-layer structure consisting of the substrate layer 11 and the sealant layer 13. Examples of methods for laminating the layers in the laminate film include sandwich lamination and dry lamination.

The base layer 11 must be strong enough to protect the contents F, strong enough as a printing base to withstand the stress of the printing process, and easy to tear when opening the laminated film. Therefore, 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.

The properties of the functional film used for the base layer 11 include barrier properties, puncture resistance, and straight-line cutting properties. Specific examples of functional films include transparent vapor-deposited films that have been given barrier properties in advance, and straight-line cutting films with straight-line cutting properties. Straight-line cutting films have straight-line cutting properties that guide linear tearing in a predetermined cutting direction, and the packaging bag 102 (Figure 2, etc.) is guided to tear in a straight line from one side seal portion 8 to the other side seal portion 8 due to the straight-line cutting properties of the base layer 11, which will be described later. The thickness of the film that makes up the base layer 11 can be selected as appropriate, but a thickness of approximately 12 to 25 μm is preferable.

The material for the intermediate layer 12 can be selected appropriately 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, and an adhesive layer. The aluminum layer constituting the intermediate layer 12 may be, for example, a barrier layer made of annealed aluminum foil, preferably approximately 6 to 15 μm thick. 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 patterned layer, or other colored ink layer. The adhesive layer constituting the intermediate layer 12 may be, for example, a dry lamination adhesive commonly used in dry lamination methods. From the perspective of protecting the contents F, the intermediate layer 12 may be a film layer similar to that used for the base layer 11 (e.g., a polyester film such as PET film), or the straight-cut film described above.

The sealant 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. For example, the bonding can be performed by dry laminating or extrusion laminating the base layer 11 or 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 (Figures 3 and 4). Furthermore, the sealant layer 13 can be any layer formed from a thermo-adhesive resin that can be melted and welded together by heat, so the sealant layer 13 can be selected appropriately based on the physical properties required of the packaging bags 101, 102. For example, a layer with the straight-cutting property described above may be used.

Specific examples of 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 solid polypropylene (CPP) film. The thickness of the film that constitutes sealant layer 13 can be determined appropriately taking into account the required physical properties (heat sealability) and cost, but is preferably approximately 10 to 100 μm, and particularly approximately 40 to 60 μm.

Specific examples of the general laminate structure (base layer 11/intermediate layer 12/sealant layer 13) of the laminated film (front sheet 1A, back sheet 1B, bottom sheet 1C) are 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:

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: a 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.

The upper part of the packaging bags 101, 102 is provided with an opening structure and a resealing structure. 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 thermoplastic resin. When opening, the laminated film (front sheet 1A, back sheet 1B) tears 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 opening triggers, 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.

Because the opening structure is located between the head seal portion 10 and the zipper member 2 (see Figures 1 and 2B), when the packaged product 201 is opened using the opening structure, the portion including the head seal portion 10 is cut off, allowing the packaging bags 101, 102 to be opened and closed (resealed and resealed) using the zipper member 2 (zipper function). Figure 5 shows the opening 10h, which has been torn (in the direction of arrow ma) by the guide of the first and second cut lines 3, 4, creating a step 5.

Furthermore, since the zipper member 2 is located 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 initially opened, and depending on the contents F, they may become easily caught when removed. Therefore, if resealing and reopening of the packaging bags 101, 102 is not required, the zipper member 2 may be omitted.

As shown in Figures 3 and 4, the zipper member 2 is disposed between the front sheet 1A and the back sheet 1B. It is composed of a concave stripe member 2a disposed in the sealant layer 13 of the front sheet 1A and a convex stripe member 2b disposed in the sealant layer 13 of the back sheet 1B. The concave stripe member 2a and the convex stripe member 2b are interlocked 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 resealing of the packaging bags 101, 102 (resealing function). Therefore, the packaging bags 101, 102 can be easily resealed without the use of adhesive tape, clips, etc., preventing moisture and dust from entering the storage space 7 and allowing the remaining contents F to be hygienically stored.

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 arrangement of the concave member 2a and the convex member 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.

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 the respective sealant layers 13. For example, a long rolled zipper member 2 is unwound and sandwiched between the front sheet 1A and back sheet 1B at a predetermined position, then heat-sealed with a heat seal bar. By feeding the zipper member 2 in accordance with the positioning of the heat seal bar, the concave stripe members 2a can be heat-sealed to the front sheet 1A and the convex stripe members 2b can be heat-sealed to the back sheet 1B. By interposing an insulating plate between the concave stripe members 2a and the convex stripe members 2b, thermal fusion between the concave stripe members 2a and the convex stripe members 2b can be prevented, making it possible to simultaneously and continuously heat-seal the zipper member 2 to the front sheet 1A and back sheet 1B.

The home plate-shaped notches 8a (Figs. 1 and 2) that make up the opening structure are formed as opening initiation structures at the upper part of the left and right side seal portions 8, at the outer edges of both ends, to serve as opening starting points (i.e., opening triggers). However, the formation range of the notches 8a is limited to the formation range of the side seal portions 8 (from the outer edges of the left and right side seal portions 8 to a position that does not reach the inner edges). Furthermore, 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 (distance from the opening 10h or the outer edge of the head seal portion 10) are the same.

The shape of the notch 8a is not limited to the home base shape, and may be a V-shape (V notch), U-shape (U notch), linear shape (I notch), polygonal shape, etc. The notch 8a used here is a UV notch (base notch) that is a home base shape created by combining a U-shape and a V-shape, and this shape has the advantages of being highly visible and easy to identify by touch. Furthermore, to prevent snagging during transport, an MP notch made up of fine scratches may be used as the notch 8a.

The orientation of the notch 8a is preferably set so that the tear direction from the notch 8a coincides with the linear tear direction (e.g., the linear cuttability of the sealant layer 13) of the laminate film (front sheet 1A, back sheet 1B). While the packaging bag 102 (Figure 2, etc.) utilizes the linear cuttability described below in the base layer 11, the use of linear cuttability is also effective in the packaging bag 101 (Figure 1, etc.). Furthermore, a marking such as a cut or opening may be provided at the location where the notch 8a is formed, allowing consumers to easily identify the opening position. This marking can be applied by gravure printing or the like when forming the printing ink layer as the intermediate layer 12.

The first and second score lines 3, 4 that make up 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. 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, in which case the same effect as when they are formed in the base material layer 11 can be obtained.

The first and second score lines 3, 4 are preferably formed by laser cutting using a pulsed laser or the like (laser tear guide). Lasers used for this 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.

In the packaging bag 101 (Figure 1), first and second cut lines 3, 4 are formed in the front sheet 1A and 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 overall shape. In other words, the linear portions 3b, 4b have branched portions 3a, 4a with sideways V-shaped (so-called bird's foot) shapes at both ends (the bent positions of the V-shaped portions on both sides are connected horizontally by the linear portions 3b, 4b).

In contrast, in the packaging bag 102 (Figure 2), there is an area between the left and right side seal portions 8 on the front sheet 1A and back sheet 1B 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 separate parts, separated to the left and right, with left and right linear portions 3b, 4b and branched portions 3a, 4a branching off from the end of one of the linear portions (notch 8a side).

As described above, in packaging bags 101, 102 (Figs. 1 and 2), the first cut line 3 on the front sheet 1A that assists 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 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 formation range of the notch 8a on both 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 to surround the notch 8a from one side.

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 offset in the vertical direction of the packaging bags 101, 102 (the linear shapes do not match), so the linear portions 3b, 4b of the first and second cut lines 3, 4 are parallel to each other. For example, the offset 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 described below (Figures 6 and 7), this offset is d1 = 1 mm or d2 = 2 mm.

Although the relative positions of the linear portions 3b and 4b to the front and back sheets 1A and 1B are shifted as described above, the tip of the branched portion 3a at the first cut line 3 on the front sheet 1A and the tip of the branched portion 4a at the second cut line 4 on the back sheet 1B are aligned. In other words, the extension ranges (i.e., tear openings) of the tips of the branched portions 3a and 4a are aligned. 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 giving the branched portion 4a an asymmetrically deformed shape, 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 and 4b. Therefore, it is possible to maintain the branched state of the branched portion 4a from the linear portion 4b so that the formation range of the notch 8a is located within the expansion range of the tips of the branched portions 3a and 4a.

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 both formed so as not to contact the notch 8a. Because the notch 8a is positioned within the expansion range of the tips of the branched portions 3a and 4a, 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 apart, guided by the first and second cut lines 3 and 4. Finally, the portion including the head seal 10 is cut off, leaving the packaging bags 101 and 102 in the opened state shown in Figure 5.

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

In the packaging bag 102 (Figure 2), the straight-cutting property of the base 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. Furthermore, layers other than the base layer 11 may have straight-cutting property. In other words, it is sufficient for at least one layer of the base layer 11, intermediate layer 12, and sealant layer 13 to have straight-cutting property that guides linear tearing from one side seal portion 8 to the other side seal portion 8.

When filling the packaging bags 101, 102 (Figs. 1 and 2) with contents F through the opening 10h, the claws of the 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 portion of the front and back sheets 1A, 1B. If the area formed by 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 minimize the area formed by the first and second cut lines 3, 4 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.

From this perspective, in 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 off from at least one end thereof, and the straight-line portions 3b, 4b are offset and parallel to each other, making it possible to minimize the vertical area of the first and second cut lines 3, 4 (filling suitability). In 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 packaging bag 102), so the first and second cut lines 3, 4 suffer almost no damage when filling the contents F.

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

In addition, in packaging bags 101, 102, by giving branched-shaped portion 4a an asymmetrically deformed shape, the formation range of notch 8a is positioned within the expansion range of the tips of branched-shaped portions 3a, 4a, making it possible to reliably guide tearing from notch 8a to branched-shaped portions 3a, 4a (bag cuttability). As a result, linear-shaped portions 3b, 4b can be extended close to notch 8a, making it possible to increase the formation range of step 5 in the left-right direction. Near notch 8a, linear-shaped portions 3b, 4b sustain minimal damage when filling with contents F (filling suitability), and the large left-right step 5 makes bag opening even easier.

Figure 6 shows a specific example of the first and second cut lines 3, 4 used in the first embodiment, and Figure 7 shows a specific example of the first and second cut lines 3, 4 used in the second embodiment. In Figures 6 and 7, the dimensions of each part are indicated by d1 = 1 mm, d2 = 2 mm, d3 = 3 mm, and d4 = 4 mm. Considering the use of packaging bags 101, 102 according to the contents F (food, etc.), for example, if the dimensions of packaging bags 101, 102 are length (vertical direction): 156 mm x width (horizontal direction): 120 mm, the horizontal dimensions of the first and second cut lines 3, 4 are as follows: branched-shaped portions 3a, 4a: 4 mm, linear-shaped portion 3b: 107 mm, and the vertical dimension of branched-shaped portions 3a, 4a: 4 mm.

Figure 6(A) shows the first and second cut lines 3, 4 used in the packaging bag 101 (Figure 1), and Figure 7(A) shows the first and second cut lines 3, 4 used in the packaging bag 102 (Figure 2). In the first and second cut lines 3, 4 shown in Figures 6(A) and 7(A), the linear portions 4b are offset upward from the linear portions 3b, resulting in the formation of a step 5 (Figure 5) exposing the inner surface of the back sheet 1B. In contrast, in the first and second cut lines 3, 4 shown in Figures 6(B) and 7(B), the linear portions 4b are offset downward from the linear portions 3b, resulting in the formation of a step 5 (Figure 5) exposing the inner surface of the front sheet 1A.

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 first cut lines 3 with the same shape as the second cut lines 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 portions 3b, 4b is d1 x 2 = d2 = 2 mm.

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

In the first and second cut lines 3, 4 shown in Figures 6(A) and 7(A), the branched-shaped portions 3a have a symmetrical V-shape, while the branched-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 branched-shaped portions 3a, 4a have a symmetrical V-shape. In other words, in the first and second cut lines 3, 4 shown in Figures 6(D) and 7(D), the second cut lines 4, which have the same shape as the first cut lines 3, are arranged parallel to the first cut lines 3 in the first and second cut lines 3, 4 shown in Figures 6(A) and 7(A). Therefore, the tip of the branched-shaped portion 3a of the first cut line 3 on the front sheet 1A does not coincide with the tip of the branched-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 cuttability).

The first and second cut lines 3, 4 shown in Figure 7(E) are the first and second cut lines 3, 4 shown in Figure 7(A) with the linear portions 3b, 4b omitted. In other words, 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 Figure 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 notch 8a is located within the spreading range of the tip of the V-shaped portions 3a, 4a (Figure 2, etc.). Therefore, as mentioned above, at least one layer of the laminated film in each of the front and back sheets 1A and 1B 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.

As explained above, because the first and second score lines 3, 4 are formed within a small area, the first and second score lines 3, 4 are less likely to become tearing points even when the packaging bags 101, 102 are subjected to force. For example, even when an automatic filling machine is used to fill and hermetically seal the contents F into the packaging bags 101, 102 through the opening 10h provided with the first and second score lines 3, 4, the filling machine's tool can be prevented from catching on the score lines 3, 4, causing the packaging bags 101, 102 to tear (filling suitability). Furthermore, because the notches 8a, 18a are formed within the expansion range of the tips of the branched-shape portions (or V-shaped portions) 3a, 4a, tearing from the notches 8a, 18a is reliably guided to the score lines 3, 4 (bag cuttability). Furthermore, because the misalignment of the first and second cut lines 3, 4 causes a misalignment in the tearing position of the front and back laminate films, the openings 10h of each laminate film are easier to grasp when removing the contents F, making the packaging bags 101, 102 easier to open (bag openability). Therefore, it is possible to realize packaging bags 101, 102 that are easy to open when removing the contents F and can be opened without damaging the first and second cut lines 3, 4 used for opening when filling the contents F.

As described above, packaging bags 101, 102 have excellent manufacturability and excellent properties such as ease of removal of contents F and ease of resealing and reopening after opening, allowing for low cost and high usability. The opening and resealing structures described above are not limited to standing-type packaging bags 101, 102, 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.

The following provides a more detailed description of packaging bags embodying the present invention. The packaging bags E1 and E2 (FIGS. 8A and 8B) of Examples 1 to 4 (EX1 to 4) and the packaging bags C1 and C2 (FIGS. 8C and 8D) of Comparative Examples 1 to 4 (CX1 to CX4) are flat pouches with a three-sided seal, produced by heat-sealing the front sheet 1A and back sheet 1B together. These pouches have side seals 18 and bottom seals 19 as heat-sealed sections. The side seals 18 on both the left and right sides of the packaging bags E1, E2, C1, and C2 are each provided with a V-shaped notch 18a as an opening initiation mechanism. Similar to packaging bags 101 and 102 (FIGS. 1 and 2), a zipper member 2 is 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).

Packaging bag E1 (Fig. 8(A)) of Examples 1 and 2 (EX1, 2) has first and second cut lines 3, 4 similar to those of packaging bag 101 (Fig. 1), and packaging bag E2 (Fig. 8(B)) of Examples 3 and 4 (EX3, 4) has first and second cut lines 3, 4 similar to those of packaging bag 102 (Fig. 2). Furthermore, packaging bag C1 (Fig. 8(C)) of Comparative Examples 1 and 2 (CX1, 2) has first and second cut lines 3, 4 that are aligned in the same position on the front sheet 1A and the back sheet 1B and connect the notches 18a on both the left and right sides. In 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 linear portions connecting the oval-shaped portion to the notch 18a on both sides is formed in the front sheet 1A, and a linear second cut line 4 connecting the notches 18a on both sides is formed in the back sheet 1B.

Example 1 (EX1), FIG. 8A
The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) were PET 12 μm/printing ink/adhesive/aluminum foil 7 μm/adhesive/PE film 40 μm. The first and second cut lines 3 and 4 of the packaging bag E1 were processed on the PET surface using a _CO2 laser so that the amount of positional deviation was 1 mm in the vertical direction of the packaging bag E1.

Example 2 (EX2), FIG. 8A
The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) were 12 μm transparent vapor-deposited PET/printing ink/adhesive/50 μm PE film. The first and second cut lines 3 and 4 of the 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 the packaging bag E1 was 1 mm.

Example 3 (EX3), FIG. 8B
The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) were PET 12 μm/printing ink/adhesive/aluminum foil 7 μm/adhesive/straight-cut PET 12 μm/adhesive/PE film 40 μm. The first and second cut lines 3 and 4 of packaging bag E2 were processed on the PET surface using a _CO2 laser so that the amount of positional deviation was 1 mm in the vertical direction of packaging bag E2.

Example 4 (EX4), FIG. 8(B)
The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) were PET 12 μm/printing ink/adhesive/aluminum foil 7 μm/adhesive/straight-cut OPP 20 μm/adhesive/PE film 40 μm. The first and second cut lines 3 and 4 of packaging bag E2 were processed on the PET surface using a _CO2 laser so that the amount of positional deviation was 1 mm in the vertical direction of packaging bag E2.

<Comparative Example 1 (CX1), FIG. 8(C)>
The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) are PET 12 μm/printing ink/adhesive/aluminum foil 7 μm/adhesive/PE film 40 μm. The first and second cut lines 3 and 4 of the packaging bag C1 were processed on the PET surface using a _CO2 laser.

<Comparative Example 2 (CX2), FIG. 8(C)>
The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) were 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.

<Comparative Example 3 (CX3), FIG. 8(D)>
The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) were PET 12 μm/printing ink/adhesive/aluminum foil 7 μm/adhesive/straight-cut PET 12 μm/adhesive/PE film 40 μm. The first and second cut lines 3 and 4 of packaging bag C2 were processed on the PET surface using a _CO2 laser.

<Comparative Example 4 (CX4), FIG. 8(D)>
The packaging material specifications (laminated structure of front sheet 1A and back sheet 1B) were PET 12 μm/printing ink/adhesive/aluminum foil 7 μm/adhesive/straight-cut OPP 20 μm/adhesive/PE film 40 μm. The first and second cut lines 3 and 4 of packaging bag C2 were processed on the PET surface using a _CO2 laser.

Table 1 shows the evaluation results for filling suitability, bag cuttability, and bag openability for Examples 1 to 4 (EX1 to 4) and Comparative Examples 1 to 4 (CX1 to 4). Regarding filling suitability, ◎: 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, ◎: No tearing away from the designated position (tears away from the cut line), ○: Almost no tearing away from the designated position (tears away from the cut line), ×: Some tearing away from the designated position (tears away from the cut line). Regarding bag openability, ◎: The opening was very easy to grasp, ○: The opening was easy to grasp, ×: The opening was difficult to grasp.

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 branched portion (V-shaped portion)
3b Linear portion 4 Second cut line 4a Branched portion (V-shaped portion)
4b Linear portion 5 Step 7 Storage space 8 Side seal portion 8a Notch (opening start structure)
9 Gusset seal portion 10 Head seal portion 10h Opening 11 Base material layer 12 Intermediate layer 13 Sealant layer (thermoplastic resin layer)
18 Side seal portion 18a Notch (opening start structure)
19 Bottom seal portion 101, 102, E1, E2, C1, C2 Packaging bag 201, 202 Packaged product F Contents

Claims (11)

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. The packaging bag of claim 1, wherein the tip of the branched portion of the first cut line on the front sheet coincides with the tip of the branched portion of the second cut line on the back sheet. 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. 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. 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. 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. 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 material layer and the intermediate layer. 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. 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. 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 reopening , the zipper member being located on the storage space side of the first and second cut lines. 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 containing space.