Packaging bags

Abstract

To provide a packaging bag including a bottom tape and having a self-standing property, which can improve drop impact resistance without using an excessive material constitution for reinforcement and without damaging the self-standing property.SOLUTION: A packaging bag can stand alone, a trunk part is formed by laminates being opposed to each other and overlapped and by a peripheral edge part being sealed. An edge inside a side seal part is a boundary with an unsealed part. At a lower part of the trunk part, a bottom tape folded in a ridge folding manner with a sealant layer of the laminate on the outside is sandwiched between two pieces of laminates of the trunk part, and a bottom part is formed. At the bottom part, a convex edge curved downward is a boundary between the bottom seal part and the unsealed part, and in the neighborhood of an intersection of a side seal line and a bottom seal line, an angle (R) formed by the convex bottom seal line curved downward and a folding line in the horizontal direction of the ridge folding of the bottom tape is 30 degrees<angle (R)<40 degrees.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a packaging bag. In particular, it relates to a packaging bag made of a laminate with a plastic film as a base material, which has self-standing properties and is generally also called a standing pouch.

Background Art

[0002] A packaging bag, which is a kind of packaging material, is widely popular and is composed of a single film with a plastic film as a base material or a laminate with a plastic film as a base material. Various forms of it are used in a wide range of applications and have become indispensable for modern life.

[0003] For example, due to the water resistance of the plastic film, it is also used as a liquid container, widely used not only in the food field such as beverages and retort foods, but also in the fields of daily necessities and toiletries. Various products are filling the shelves of supermarkets, drugstores, and convenience stores. In addition, various applications have been developed mainly centered around liquid containers.

[0004] The advantages of the packaging bag include that it is cheaper than containers such as cans and bottles, can be dealt with by a fine material design according to the required quality, or is lightweight and space-saving before filling the contents and also during distribution and storage. Also, the packaging bag can be said to be environmentally adaptable from the perspective of reducing waste.

[0005] Moreover, by means of high-definition printing on the layer visible from the surface of the packaging bag, the image of the product can be enhanced, and it is possible to display the necessary information regarding the contents. Printing of barcodes, etc. also serves as a source of product distribution and marketing information.

[0006] Some packaging bags are designed to stand on their own and are commonly called standing pouches. This design offers advantages such as easier display as a product, and provides greater convenience when cooking the contents in a microwave or when removing the contents.

[0007] Such self-supporting packaging bags are constructed by layering a plastic film with a sealant layer as the base material, overlapping the sealant layers facing each other to form the body, and inserting a bottom tape between the front and back body sections, folded in a mountain shape with the sealant layer facing outwards, and sealing it to form the bottom of the packaging bag. However, if the packaging bag filled with contents is subjected to impact from being dropped, there is a risk that the bag may rupture at the sealed part of the bottom tape.

[0008] In particular, when the laminated material composition was all polyethylene or all polyolefin, there was a risk that the folded portion of the bottom tape would crack and break due to impact from dropping, causing the bag to rupture. This was especially noticeable when the temperature of the packaging bag was low.

[0009] On the other hand, environmental problems caused by plastic materials are becoming increasingly serious, and material compositions that allow for thorough recycling are welcome as monomaterial packaging materials. Furthermore, there is a strong demand for improved performance even in the case of all-polyethylene or all-polyolefin material compositions.

[0010] The standing pouches described in Patent Documents 1 and 2 have a laminated material composition and While the attempt was to solve the problem by selecting the appropriate thickness, increasing the bag-breaking strength sometimes affected other properties, resulting in over-engineering.

[0011] Alternatively, Patent Document 3 attempts to address bag rupture caused by the bottom tape, but this measure is limited to cases where the rupture occurs at the intersection of the side seal and the bottom seal line, making it an extremely limited measure against bag rupture. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Application Publication No. 7-237281 [Patent Document 2] Japanese Patent Application Publication No. 7-241967 [Patent Document 3] Patent No. 6079091 [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] The present invention has been made in view of the above circumstances, and aims to provide a packaging bag equipped with a bottom tape that is self-supporting, which can improve drop impact resistance without using an excessive material configuration for reinforcement and without impairing its self-supporting ability. [Means for solving the problem]

[0014] As a means to solve the above problems, the invention described in claim 1 is, A packaging bag comprising a laminate having a sealant layer on a plastic film as a base material, The packaging bag has a body consisting of a front body section and a rear body section, and a bottom tape at the bottom of the packaging bag that can form a bottom surface, and is self-supporting. The body is formed by overlapping laminated sealant layers facing each other and sealing the periphery. The left and right sides of the periphery of the body are sealed with side seals, and the inner edge of these side seals is the boundary line between them and the unsealed area. This boundary line is defined as the side seal line, At the bottom of the body, a bottom tape, folded in a mountain fold with the sealant layer of the laminate facing outwards, is horizontally sandwiched between the two laminates of the body and sealed at the bottom seal section to form the bottom. At the bottom, in the state of a flat surface where the bottom tape is folded in a mountain fold, the convex edge curved downward is the boundary line between the bottom seal part and the unsealed part, and this boundary line is defined as the bottom seal line, In the vicinity of the intersection of the side seal line and the bottom seal line, the angle (R) formed by the inclination of the convex bottom seal line curved downward and the horizontal folding line of the mountain fold of the bottom tape is 30 degrees < angle (R) < 40 degrees A packaging bag characterized by being as described above.

[0015] Also, the invention according to claim 2 is In the bottom seal line, the shape of the line from the intersection with the side seal line to the bottom part is smoothly connected by a curve or a straight line. The packaging bag according to claim 1, characterized by being as described above.

[0016] Also, the invention according to claim 3 is When the content is filled and viewed from above the packaging bag, the shape formed by the bottom seal line is a straight line from the side seal part to the bottom part or a shape constricted inside. The packaging bag according to claim 1 or claim 2, characterized by being as described above.

Effect of the Invention

[0018] The packaging bag has a body portion composed of a front body portion and a rear body portion, and a bottom tape capable of forming a bottom surface at the lower part of the packaging bag. When the content is filled, the bottom tape opens in a boat shape by its own weight to form a bottom surface, and the packaging bag can stand on its own.

[0019] Among the peripheral portions of the body, both the left and right sides are sealed by side seal portions. The inner edge of this side seal portion is the boundary line with the unsealed portion. At the lower part of the body, the bottom tape folded into a mountain fold with the sealant layer of the laminate facing outward is horizontally sandwiched between the two laminates of the body and sealed by a bottom seal portion to form the bottom. By doing so, a sealed space can be provided between the front body portion and the rear body portion, and the contents can be filled.

[0020] In the vicinity of the intersection of the side seal line and the bottom seal line, the angle (R) formed by the inclination of the convex bottom seal line curved downward and the horizontal folding line of the mountain fold of the bottom tape is 30 degrees < angle (R) < 40 degrees. By this, it becomes possible to provide a packaging bag that can improve the impact resistance against dropping without having an excessive material configuration for reinforcement and without impairing the self-standing property.

[0021] Alternatively, in a self-standing packaging bag (100) made of a packaging bag with relatively low impact resistance against dropping, such as a monomaterial packaging material made of polyethylene alone or polyolefin alone, it is also possible to make the packaging bag (100) that can improve the impact resistance against dropping without having an excessive material configuration for reinforcement and without impairing the self-standing property. In this case, it is also effective for purposes such as thorough recycling.

[0022] Also, according to the invention particularly described in claim 2, in the bottom seal line, since the shape of the line from the intersection with the side seal line to the bottom portion is smoothly connected by a curve or a straight line, when an external impact such as a dropping impact is applied, it is possible to avoid stress concentration occurring at a particular portion, so that it is possible to make a packaging bag that can improve the impact resistance against dropping.

[0023] Furthermore, according to the invention described in claim 3 in particular, when the contents are filled and viewed from above the packaging bag, the shape of the bottom seal line is a straight line from the side seal portion to the bottom portion, or a shape that is constricted inward, making it possible to create a packaging bag that can improve resistance to drop impact. This is made possible by the fact that the opening angle of the bottom at both ends of the boat-shaped bottom surface can be adjusted by the present invention. [Brief explanation of the drawing]

[0024] [Figure 1] Figure 1 is a schematic plan view of the side seal portion and the bottom seal portion for illustrating one embodiment of the packaging bag according to the present invention. [Modes for carrying out the invention]

[0025] The present invention will be described in more detail below with reference to Figure 1. However, the present invention is not limited to the examples shown herein. The present invention is defined by the claims.

[0026] Figure 1 is a schematic plan view of the side seal portion and the bottom seal portion for illustrating one embodiment of the packaging bag according to the present invention.

[0027] The present invention relates to a packaging bag (100) comprising a laminate having a sealant layer on a plastic film as a base material.

[0028] The plastic film is a film made of a polymer resin composition, and can be made of polyolefins (polyethylene, polypropylene, etc.), polyesters (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamides (nylon-6, nylon-66, etc.), polyimides, etc., and one or more types can be appropriately selected depending on the application and used as a laminate. The laminate can also be composed of a printed layer, a gas barrier layer, etc., as needed.

[0029] In particular, when polyethylene and polypropylene are used as plastic films, they are preferred in certain applications due to their versatility and price.

[0030] For example, as one solution to environmental problems caused by plastic materials, monomaterial packaging materials are effective as they allow for thorough recycling, and there is a strong demand for improved performance even in the case of all-polyethylene or all-polyolefin material compositions.

[0031] The sealant layer allows for the formation of a packaging bag (100) by overlapping two laminates so that the sealant layers face each other, and then heat-sealing them by heating and pressurizing them.

[0032] Polyolefin resins are commonly used as the material for the sealant layer. Specifically, ethylene resins such as low-density polyethylene resin (LDPE), medium-density polyethylene resin (MDPE), linear low-density polyethylene resin (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, and ethylene-methacrylic acid resin copolymer can be used, as well as polyethylene and polybutene blend resins, homopolypropylene resin (PP), propylene-ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α-olefin copolymer.

[0033] To form a sealant layer, a film of molten resin can be created using an extruder or the like, and then the layer can be formed on the laminate. Alternatively, a sealant layer can be formed on the surface of the laminate by laminating a material that has already been formed into a film.

[0034] According to the present invention, even in a self-supporting packaging bag (100) made of a monomaterial packaging material consisting of polyethylene alone or polyolefin alone, which has relatively low resistance to drop impact, it is possible to improve the resistance to drop impact without using an excessive material composition for reinforcement, which is the problem, and without impairing self-supporting properties.

[0035] The packaging bag (100) is self-standing and has a body (10) consisting of a front body (4) and a rear body (5), and a bottom tape (3) at the bottom (20) of the packaging bag that can form a bottom surface. However, the rear body (5) is not visible in Figure 1 because it overlaps with the front body (4).

[0036] Furthermore, although the bottom tape is folded flat as shown in Figure 1, when the contents are filled, the weight causes the fold line (24) to open, expanding into a boat shape and forming a bottom surface at the bottom of the packaging bag (100), thus enabling the packaging bag (100) to stand on its own.

[0037] The body portion (10) is formed by overlapping the sealant layers of the laminate facing each other and sealing the periphery. Of the periphery of the body portion (10), both the left and right sides are sealed with side seal portions (1). The inner edge of this side seal portion (1) is the boundary line between it and the unsealed portion, and in this invention, this boundary line is defined as the side seal line (11).

[0038] Furthermore, at the lower part of the body (10), a bottom tape (3) is folded in a mountain fold with the sealant layer of the laminate facing outwards, and is horizontally sandwiched between the two laminates of the body (10), and sealed with a bottom seal portion (2) to form the bottom. At the bottom, the bottom tape (3) is folded in a mountain fold and has a convex edge that curves downwards, which is the boundary line between the bottom seal portion and the unsealed portion, and in this invention, this boundary line is defined as the bottom seal line (21).

[0039] In the present invention, near the intersection (22) of the side seal line (11) and the bottom seal line (21), the angle (R) formed by the inclination of the downwardly curved convex bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) is 30 degrees < Angle (R) < 40 degrees It is characterized by being such.

[0040] Through repeated experiments in the process of diligently investigating the present invention, we found that the angle (R) being within this range, which is the angle (R) between the inclination (30) near the intersection (22) of the fold line (24) and the bottom seal line (21), is effective in creating a packaging bag (100) equipped with a bottom tape (3) that is self-supporting, without requiring an excessive material configuration for reinforcement and without compromising its self-supporting ability, thereby improving its resistance to drop impact.

[0041] In other words, when the packaging bag (100) according to the present invention is filled with contents and the bottom tape (3) is opened, the bottom surface takes on a boat-like shape and becomes self-supporting, even if the constituent material of the packaging bag (100) is a material with low tensile strength, it is possible to obtain the effect of absorbing and mitigating the impact when subjected to an impact, making it less likely to tear.

[0042] Furthermore, in the bottom seal line (21), the shape of the line from the intersection point (22) with the side seal line (11) to the bottom portion can be a curved or straight line that smoothly connects the two points.

[0043] This is because the smooth, continuous shape of the bottom seal line (21) makes it possible to avoid localized stress concentration when subjected to external impacts, compared to when there are corners, thus effectively improving the drop impact resistance of the packaging bag (100).

[0044] Furthermore, when the contents are filled and viewed from above the packaging bag, the shape of the bottom seal line (21) can be a straight line from the side seal portion (1) to the bottom, or a shape that is constricted inward.

[0045] This means that, according to the present invention, the bottom opening angle when the bottom of the packaging bag (100) opens into a boat shape is adjusted, and the range of the angle (R) between the inclination (30) of the bottom seal line (21) near the intersection (22) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) is 30 degrees < Angle (R) < 40 degrees This becomes possible because of that.

[0046] In this way, according to the present invention, it is possible to provide a packaging bag equipped with a bottom tape that is self-supporting, which can improve drop impact resistance without using excessive material for reinforcement and without impairing its self-supporting ability. [Examples]

[0047] The present invention will be further described below with reference to examples. However, the present invention is not limited to the examples shown herein. The present invention is defined by the claims.

[0048] A sample of a self-standing packaging bag for evaluation was prepared, filled with contents, and evaluated by conducting a drop test. The symbols used in Figure 1 will be used in the following explanation.

[0049] The laminated structure of the packaging bag body is as follows: Size: Width 145mm x Height 220mm x Bottom fold 40mm Seal width: 5mm Layer structure: From the outside of the packaging bag HDPE (35 μm thickness) / LLDPE (100 μm thickness) That's what I decided. Furthermore, the curvature of the bottom portion (6) of the bottom seal portion (2) of the bottom tape (3) was set to a radius of 65 mm.

[0050] The following liquids were used as the contents for evaluation. 400cc of 5℃ cold water That's what I decided.

[0051] Two drop tests were conducted, and the details are as follows:

[0052] (First evaluation) The first evaluation was conducted using the following method. The evaluation samples were subjected to drop tests, being dropped 10 times from a height of 1 meter. The evaluation was based on a visual inspection of the condition of the ruptured bags.

[0053] <Example 1> The angle (R) between the inclination (30) of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) was set to 36 degrees. This is within the range defined in the present invention.

[0054] <Comparative Example 1> The angle (R) between the inclination (30) of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) was set to 40 degrees. This deviates from the scope defined in the present invention.

[0055] (Second evaluation) As an additional check, a second evaluation was conducted using the following method. Samples were created by varying the angle (R) between the inclination (30) of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3). (1) Five samples were evaluated by performing a drop test 10 times. (2) Next, repeated drop tests were conducted up to 50 times to evaluate the average number of bag breaks. The evaluation was based on a visual inspection of the condition of the ruptured bags.

[0056] <Example 2> The angle (R) between the inclination of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) was set to 38 degrees. This is within the range defined in the present invention.

[0057] <Example 3> The angle (R) between the inclination (30) of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) was set to 36 degrees. This is within the range defined in the present invention.

[0058] <Example 4> The angle (R) between the inclination (30) of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) was set to 34 degrees. This is within the range defined in the present invention.

[0059] <Example 5> The angle (R) between the inclination (30) of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) was set to 32 degrees. This is within the range defined in the present invention.

[0060] <Comparative Example 2> The angle (R) between the inclination (30) of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) was set to 40 degrees. This deviates from the scope defined in the present invention.

[0061] <Comparative Example 3> The angle (R) between the inclination (30) of the bottom seal line (21) and the horizontal fold line (24) of the mountain fold of the bottom tape (3) was set to 30 degrees. This deviates from the scope defined in the present invention.

[0062] The results of the first evaluation are shown in Table 1.

[0063] [Table 1]

[0064] The results shown in Table 1 indicate that in Example 1 of the present invention, all 10 samples maintained their shape without rupturing during 10 repeated drop tests.

[0065] In contrast, in Comparative Example 1, which deviated from the scope defined in the present invention, all 10 samples ruptured and failed to maintain their shape.

[0066] This means that, according to the present invention, the bottom opening angle when the bottom of the packaging bag opens into a boat shape is adjusted, and the range of the angle (R) between the bottom seal line and the horizontal fold line of the bottom tape's mountain fold is 36 degrees in the sample of Example 1. 30 degrees < Angle (R) < 40 degrees Its effectiveness was verified by being within the specified range.

[0067] The results of the second evaluation are shown in Table 2.

[0068] [Table 2]

[0069] The results shown in Table 2 are additional confirmations based on the first evaluation, and it can be seen here as well that Examples 2 to 5 according to the present invention are clearly superior to Comparative Examples 2 and 3, which deviate from the scope defined in the present invention.

[0070] First, five samples were subjected to a drop test repeated 10 times and evaluated. The results showed that in each of Examples 2 to 5 according to the present invention, all five samples maintained their shape without the bags bursting. This is consistent with the results of the first evaluation.

[0071] In contrast, Comparative Example 2, which deviated from the scope defined in the present invention, resulted in all five samples rupturing, and in Comparative Example 3, one out of five samples ruptured, failing to maintain its shape. These results are consistent with the first evaluation, and it is clear that all of the comparative examples have practical problems.

[0072] Next, repeated drop tests were conducted up to 50 times to evaluate the average number of bag breakages. The results showed that in Example 2, there were no breakages in 28 breakages; in Example 3, there were no breakages in 50 breakages; in Example 4, there were no breakages in 41.2 breakages; and in Example 5, there were no breakages in 50 breakages. All of these were at a high level, differing from the comparative examples and falling within the practical range.

[0073] In contrast, Comparative Example 2, which deviates from the scope defined in the present invention, had an average bag breakage count of 6.2 times, clearly indicating that it is prone to breakage. Comparative Example 3 had 29.2 breakages, but as mentioned above, one out of five samples broke within 10 repetitions, which, considering this, is a problem for practical use.

[0074] In this way, the present invention has been verified to provide a packaging bag that has a bottom tape and is self-supporting, and that can improve drop impact resistance without using excessive materials for reinforcement or compromising its self-supporting ability. [Explanation of Symbols]

[0075] 1. Side seal section 2. Bottom seal section 3. Bottom tape 4. Front side of the torso 5. Rear torso 6...Bottom 10. Torso 11. Side seal wire 20...bottom of packaging bag 21. Bottom seal wire 22...intersection 24...Folded line 30... Inclination 100...packaging bag R...R

Claims

1. A packaging bag comprising a laminate having a sealant layer on a plastic film as a base material, The packaging bag has a body consisting of a front body section and a rear body section, and a bottom tape at the bottom of the packaging bag that can form a bottom surface, and is self-supporting. The body is formed by overlapping laminated sealant layers facing each other and sealing the periphery. The left and right sides of the periphery of the body are sealed with side seals, and the inner edge of these side seals is the boundary line between them and the unsealed area. This boundary line is defined as the side seal line, At the bottom of the body, a bottom tape, folded in a mountain fold with the sealant layer of the laminate facing outwards, is horizontally sandwiched between the two laminates of the body and sealed at the bottom seal section to form the bottom. At the bottom, in a flat state where the bottom tape is folded in a mountain fold, the downwardly curved convex edge is the boundary line between the bottom sealed portion and the unsealed portion. This boundary line is defined as the bottom seal line, Near the intersection of the side seal line and the bottom seal line, the angle (R) between the inclination of the bottom seal line, which is a smoothly continuous curved line extending from the intersection with the side seal line to the bottom portion and curves downwards, and the horizontal fold line of the mountain fold of the bottom tape, is 30 degrees < Angle (R) < 40 degrees A packaging bag characterized by the following:

2. The packaging bag according to claim 1, characterized in that, when filled with contents and viewed from above, the shape of the bottom seal line is a straight line from the side seal portion to the bottom portion, or a shape that is constricted inward.

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