JP2023094431A - Food packaging bag, method for manufacturing food packaging bag, and method for reinforcing food packaging bag - Google Patents

Abstract

To provide a food packaging bag that is hard to tear and highly reusable.SOLUTION: A food packaging bag 1A is formed of a film. The food packaging bag has: a pair of main surface portions 11, 12 arranged opposite each other in a flat bag state; a pair of fusing seal portions 13, 14 formed at both ends in a width direction of the pair of main surface portions 11, 12; and a pair of reinforcement seal portions 15A, 16A formed inside the pair of fusing seal portions 13, 14 with respect to the width direction of the pair of main surface portions 11, 12 to reinforce the pair of fusing seal portions 13, 14.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a food packaging bag, a method for manufacturing a food packaging bag, and a method for reinforcing a food packaging bag.

Conventional food packaging bags for loaves of bread and sweet breads are sold in a state of being tied with a tie that twists and fixes the opening, i.e., a plastic plate of about 2 cm square with a slit, tape, string, or the like. A container containing a plurality of items, or even a single large item, is highly convenient because it can be opened and closed many times with a resealable binding, and is often used.

However, since packaging with such a binding tool is simple, there is a gap in the binding part of the packaging bag, and there is a drawback that foreign matter cannot be prevented from entering. Therefore, the present applicants have proposed a surface layer (A) containing a propylene resin, an intermediate layer (C) containing a propylene resin, and a 1 - We propose a laminated film for easy-open food packaging bags, which has a butene-based copolymer (b1) and a heat seal layer (B) containing a copolymer (b2) consisting essentially of propylene and ethylene. (Patent Document 1). When a bread bag or the like is produced using the laminated film for easy-open food packaging bags, the heat-sealed layer of the three layers is usually placed inside the bag, and processed into a bottom gusset bag by a bag making machine. However, at this time, the fusion seal temperature and the bag-making speed are adjusted so that the fusion seal strength of the side portions and the bottom gusset portion (folded portion of the bottom portion) of the bottom gusset bag is within a predetermined range.

JP 2006-213065 A

In recent years, with the promotion of recycling and the charging of garbage bags, there is a growing need for alternatives to garbage bags at home. Among the bags used at home, bread bags, for example, are the second easiest to obtain after plastic shopping bags, and are highly convenient because they are gusseted bottom bags that stand on their own due to the gussets at the bottom. However, depending on the weight of the garbage contained in the bread bag, a load may be applied to the fusion seal provided on the side surface of the bottom gusset bag, and the bread bag may break. In addition, the user may provide several drainage holes in or near the bottom gusset in order to accommodate water-containing materials such as food waste. There is a problem that the bread bag is torn without being caught.

An object of the present invention is to provide a food packaging bag that is hard to tear and highly reusable, a method for manufacturing the food packaging bag, and a method for reinforcing the food packaging bag.

In order to achieve the above object, the present invention provides the following means.
[1] A food packaging bag formed of a film,
a pair of main surface portions facing each other in a flat bag state;
a pair of fusion seal portions formed at both ends in the width direction of the pair of main surface portions;
a pair of reinforcing seal portions formed inside the pair of fusion seal portions in the width direction of the pair of main surface portions to reinforce at least a portion of the pair of fusion seal portions;
A food packaging bag having

[2] further comprising a bottom gusset disposed on the opposite side of the opening of the pair of main surface portions and provided over the entire width direction of the pair of main surface portions;
the pair of fused seals extending from the opening to the bottom gusset;
The food packaging bag according to [1] above, wherein the pair of reinforcing seal portions is formed adjacent to the pair of fusion seal portions.

[3] When the food packaging bag is opened, a triangular apex, which is an intersection point between two width-direction folded end portions of the bottom gusset and the fusion seal portion, is reinforced with the reinforcement seal portion. The food packaging bag according to [2] above.

[4] The food packaging bag according to [1] above, wherein the reinforcement seal portion extends over the entire fusion seal portion along the extending direction of the fusion seal portion.

[5] The food packaging bag according to any one of [1] to [4] above, wherein the reinforcing seal portion is a heat-sealed portion in which a pair of main surface portions are heat-sealed to each other.

[6] The above [1] to [1]-[ 5] The food packaging bag according to any one of the above items.

[7] The food packaging product according to [6] above, wherein the film is a laminated film obtained by laminating a plurality of films made of one or two of unstretched olefinic resins and biodegradable resins. bag.

[8] The laminated film is
a surface layer (A) containing a propylene-based resin;
an intermediate layer (C) containing a propylene-based resin;
A 1-butene-based copolymer (b1) containing 1-butene and propylene as essential components and a copolymer (b2) containing propylene and ethylene as essential components, having a thickness of 1 to 8 μm. a heat seal layer (B);
The food packaging bag according to [6] or [7] above.

[9] A method for producing a film-formed food packaging bag, comprising:
a step of forming a pair of reinforcing seal portions on at least a portion of portions where the pair of fusion seal portions are formed on both sides in the width direction of the pair of main surface portions that are opposed to each other;
a step of forming a pair of fusion seal portions at both ends in the width direction of the pair of main surface portions;
A method for manufacturing a food packaging bag.

[10] A method for reinforcing a film-formed food packaging bag having a pair of fusion-cut seal portions on both sides in the width direction of a pair of main surface portions opposed to each other in a flat bag state, wherein at least the fusion-cut seal portion A method for reinforcing a food packaging bag, wherein a part of the bag is reinforced with a reinforcing seal.

INDUSTRIAL APPLICABILITY According to the present invention, a food packaging bag that is hard to break and highly reusable, a method for manufacturing the food packaging bag, and a method for reinforcing the food packaging bag are provided.

FIG. 1 is a perspective view schematically showing a flat bag state of an example of a food packaging bag according to an embodiment of the present invention. FIG. 2(A) is a plan view of the food packaging bag of FIG. 1, and FIG. 2(B) is a cross-sectional view taken along line AA. FIG. 3 is a perspective view showing a state in which the food packaging bag of FIG. 1 is opened. FIG. 4(A) is a diagram schematically showing the range in which the fusion seal portion is formed in the side view of the food packaging bag of FIG. 3, and FIG. FIG. 4 is a diagram schematically showing a range in which 5 is a cross-sectional view showing an example of the laminated structure of the laminated film forming the food packaging bag of FIG. 1. FIG. FIGS. 6A to 6C are schematic diagrams showing an example of a method for manufacturing a food packaging bag according to this embodiment. 7(A) and 7(B) are schematic diagrams showing modifications of the range where the fusion seal portion of FIG. 4(A) and the reinforcing seal portion of FIG. 4(B) are formed. 8(A) and 8(B) are schematic diagrams showing other modifications of the range where the fusion seal portion of FIG. 4(A) and the reinforcing seal portion of FIG. 4(B) are formed. 9(A) and 9(B) are schematic diagrams showing other modifications of the range in which the fusion seal portion of FIG. 4(A) and the reinforcing seal portion of FIG. 4(B) are formed. FIG. 10 is a plan view showing a modification of the food packaging bag of FIG. 2(A).

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the drawings used in the following description, the scale of dimensions may vary depending on the component in order to make it easier to see each component, and the dimensional ratio of each component may not necessarily be the same as the actual Make it not exist. In addition, the structures, materials, etc. exemplified in the following description are only examples, and the present invention is not necessarily limited to them, and it is possible to carry out the present invention with appropriate modifications within the scope of not changing the gist thereof. .

<Structure of food packaging bag>
FIG. 1 is a perspective view schematically showing a flat bag state of an example of a food packaging bag according to an embodiment of the present invention, and FIG. 2(A) is a plan view of the food packaging bag of FIG. , and FIG. 2B is a cross-sectional view along the line AA. 1 and 2, a bottom gusset bag will be described as an example of a food packaging bag.
As shown in FIG. 1, the food packaging bag 1A is a film-formed food packaging bag, and includes a pair of main surface portions 11 and 12 facing each other in a flat bag state, and the pair of main surface portions 11 and 12 facing each other in a flat bag state. , 12, and a pair of fusion seals 13, 14 formed inside the pair of fusion seals 13, 14 in the width direction of the pair of main surface portions 11, 12. A pair of reinforcing seal portions 15A and 16A that reinforce the portions 13 and 14 are provided.

The food packaging bag 1A further has a bottom gusset 18 arranged on the opposite side of the pair of main surfaces 11 and 12 from the opening 17 and provided over the entire width direction of the pair of main surfaces 11 and 12. ing. In this embodiment, a pair of fused seals 13 , 13 extend from opening 17 to bottom gusset 18 . A pair of reinforcing seal portions 15A and 16A are formed adjacent to the pair of fusion seal portions 13 and 14, respectively.

The main surface portion 11 is composed of a laminated film in which three sheets of films are laminated in this embodiment. Similarly, the main surface portions 11 and 12 are not limited to three films, and may be composed of a laminated film formed by laminating a plurality of films, or may be a single layer film. The main surface portions 11 and 12 have, for example, a rectangular shape in plan view in a flat bag state. A specific configuration of the laminated film will be described later.

The pair of fusion-cut seal portions 13 and 14 are formed by fusion-cutting both width direction end portions of the pair of main surface portions 11 and 12 in a state in which two laminated films constituting the pair of main surface portions 11 and 12 are arranged facing each other. This is the site where the body is located (Fig. 2(B)). The fusion seal portion 13 is formed at one end portion in the width direction of the pair of main surface portions 11 and 12 , and the fusion seal portion 14 is formed at the other end portion in the width direction of the pair of main surface portions 11 and 12 . The pair of fusion seal portions 13 and 14 are formed, for example, in a linear shape at the outer contours of both widthwise end portions of the pair of main surface portions 11 and 12 . In the present embodiment, the pair of fusion seal portions 13 and 14 are arranged in the direction orthogonal to the width direction of the pair of main surface portions 11 and 12 (the direction from the opening 17 toward the bottom gusset 18). is formed throughout.

The pair of reinforcing seal portions 15A and 16A are formed by, for example, two laminated films forming the pair of main surface portions 11 and 12 facing each other, and the pair of fused seal portions 13 and 16A in the width direction of the pair of main surface portions 11 and 12. 14, which is formed by heat-sealing the two laminated films (FIG. 2(B)). The pair of reinforcing seal portions 15A and 16A are formed in a linear or band shape along the shape of the pair of fusion seal portions 13 and 14, for example.

In this embodiment, the reinforcing seal portion 15A extends over the entire fusion seal portion 13 along the extending direction of the fusion seal portion 13 . Similarly, the reinforcing seal portion 16A also extends over the entire fusion seal portion 14 along the extending direction of the fusion seal portion 14 .

The bottom gusset 18 is provided at the bottom of the food packaging bag 1A and is folded inside the bag in the flat bag state. The bottom gusset 18 is normally folded once, and is valley-folded when viewed from the outside (bottom side) of the food packaging bag 1A.

The food packaging bag 1</b>A may have a printed portion 19 printed along the width direction of the pair of main surfaces 11 and 12 near the opening 17 . Although the shape of the printing portion 19 is not particularly limited, it is, for example, strip-shaped. Further, the number of printing units 19 may be plural or may be one.

Also, the food packaging bag 1A may have a thermally welded portion (not shown) formed along the width direction of the pair of main surface portions 11 and 12 on the side opposite to the opening portion 17 of the printed portion 19, for example. good. The shape of the thermally welded portion is not particularly limited, but is, for example, strip-shaped. The number of thermally welded portions may be plural or one.

FIG. 3 is a perspective view showing a state in which the food packaging bag 1A of FIG. 1 is opened. 4(A) is a diagram schematically showing a range in which the fusion seal portion 13 is formed in a side view of the food packaging bag 1A of FIG. 3, and FIG. It is a figure which shows typically the range in which 15 A of parts are formed.
As shown in FIG. 3, when the opening 17 of the food packaging bag 1A is opened and air or the like is sent thereinto, the bottom gusset 18 is opened to form a square bottom with a square bottom surface, thereby forming a food packaging bag. The bag 1A can stand on its own. Food such as bread can be filled in the food packaging bag 1A.

When the food packaging bag 1A is opened, the food packaging bag 1A has a bottom surface 21, a first side surface 22 and a second side surface 23 extending from two opposite sides of the bottom surface 21 toward the opening 17, It has a third side surface 24 and a fourth side surface 25 extending from the remaining two opposite sides toward the opening 17 . The first side surface 22 and the second side surface 23 are formed by a portion of the main surface portion 11 , a portion of the main surface portion 12 and a portion of the bottom gusset 18 . A fusion seal portion 13 and a reinforcing seal portion 15A are formed on the first side surface 22, and a fusion seal portion 14 and a reinforcing seal portion 16A are formed on the second side surface 23. As shown in FIG. The third side surface 24 is formed by a portion of the main surface portion 11 , and the fourth side surface 25 is formed by a portion of the main surface portion 12 .

On the first side surface 22, a triangular apex 26, which is the intersection of the two width-direction folded ends 18a and 18b of the bottom gusset 18 and the fusion seal portion 13, is fused by the fusion seal portion 13, and is further reinforced seal portion. reinforced by 15A. The triangular vertex portion 26 is a portion that is likely to be subjected to a load due to the weight of the stuffing when the food packaging bag 1A is filled with items. By doing so, the strength of the food packaging bag 1A is further improved.

In this embodiment, the reinforcing seal portion 15A extends over the entire fusion seal portion 13 along the extending direction of the fusion seal portion 13 . As in the present embodiment, the reinforcing seal portion 15A extends over the entire fusion seal portion 13 along the extending direction of the fusion seal portion 13, thereby reinforcing the triangular vertex portion 26 and By reinforcing the fusion cut seal portion, the strength of the food packaging bag 1A can be further improved.

[Film structure]
The film constituting the food packaging bag 1A is preferably a laminated film formed by laminating a plurality of films made of one or more materials selected from olefin resins, biomass resins and biodegradable resins. . A plurality of films constituting the laminated film may be made of different materials or the same kind of materials.

If the laminated film is made of olefin-based resin, it is possible to reuse the sheet heel. For example, after putting garbage in the bag, the opening can be sealed by heat welding, etc., so it can be reused as an airtight bag. becomes.
When the laminated film is made of biomass-based resin, it can contribute to _CO2 reduction when disposing of the bag.
When the laminated film is made of a biodegradable resin, for example, after putting garbage in the bag, the opening can be sealed as necessary, and the bag can be used as fertilizer.

Moreover, the laminated film is more preferably formed by laminating a plurality of films made of one or two kinds of non-stretched olefinic resins and biodegradable resins. When the film that constitutes the laminated film is made of one or two of unstretched olefin resin and biodegradable resin, the laminated film does not tear easily, and when the laminated film is punctured with chopsticks or the like, a hole is formed. Also, the pores are less likely to expand when an external force is subsequently applied. Therefore, it is possible to put a water-containing material such as raw garbage in the bag and squeeze the bag together to remove the water.

As the unstretched olefin resin, for example, a propylene resin such as a propylene homopolymer, a propylene-α-olefin random copolymer, a propylene-α-olefin block copolymer, or the like can be used. On the other hand, polyethylene resins include linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE), linear high density polyethylene (LHDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE). ), polyethylene resins such as high-density polyethylene (HDPE), ethylene-butene-rubber copolymer (EBR), ethylene-propylene-rubber copolymer (EPR), ethylene-vinyl acetate copolymer (EVA), ethylene - methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH ), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), etc.; A combined ionomer and the like may be mentioned, and they may be used singly or in combination of two or more.

Biomass-based resins include plant-derived biomass polyethylene. The resin is a polyethylene-based resin produced from plant-derived ethylene starting from sugarcane, corn, beet, or the like. Examples of the biomass polyethylene include linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE), linear high density polyethylene (LHDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high Density polyethylene (HDPE) and the like may be mentioned, and these may be used alone or in combination of two or more. Other examples include tall oil (a by-product of pulp production), biomass polypropylene and biomass polyethylene made from waste cooking oil (recycled).

Biodegradable resins include polyethylene succinate (PES), polybutylene succinate (PBS), polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxybutyrate (PHB), polycaprolactone (PCL), poly Mixture or copolymer of caprolactone and polybutylene succinate (PCL/PBS), copolymer of polyhydroxybutyrate and polyhydroxyvalerate (PHB/PHV), mixture of polybutylene succinate and polybutylene adipate Alternatively, resins such as copolymers (PBS/PBA), copolymers of polyethylene terephthalate and polyethylene succinate (PET/PES), copolymers of polybutylene terephthalate and polybutylene adipate (PBT/PBA), etc. . Each of the above resins may be used alone or in combination of two or more.

A single layer may be sufficient as the film which comprises 1 A of food packaging bags. When the film constituting the food packaging bag 1A is a single layer, the film is preferably made of a material selected from olefin resins, biomass resins, and biodegradable resins, as described above. It is more preferable to be made of either a system resin or a biodegradable resin.

FIG. 5 is a cross-sectional view showing an example of the laminated structure of the laminated film that constitutes the food packaging bag 1A of FIG. As shown in FIG. 5, the laminated film (I) includes a surface layer (A) containing a propylene-based resin, an intermediate layer (C) containing a propylene-based resin, and 1-butene and propylene. A heat seal layer having a thickness of 1 μm or more and 8 μm or less, containing a 1-butene copolymer (b1) as an essential component and a copolymer (b2) as an essential component of propylene and ethylene ( B). As described above, the laminated film (I) constitutes the pair of principal surfaces 11 and 12 (see FIG. 2(B)).
By forming the pair of main surface portions 11 and 12 with the laminated film (I), the heat sealability is high, the strength of the pair of reinforcing seal portions 15A and 16A is improved, and the fusion seal portions 13 and 14 are reinforced more firmly. can do.

Examples of the surface layer (A) include homopolymers of propylene; random copolymers of propylene and ethylene; block copolymers of propylene and ethylene; copolymers of propylene and α-olefins other than ethylene. A propylene-based copolymer such as a coalescence, etc.; Resin layers obtained by mixing other thermoplastic resins such as linear low-density polyethylene and various additives can be used.

Examples of the intermediate layer (C) include homopolymers of propylene, random copolymers of propylene and ethylene, block copolymers of propylene and ethylene, and copolymers of propylene and α-olefins other than ethylene. The main component is one or more propylene resins such as coalescence, preferably 70% by weight or more, and if necessary, ethylene-1-butene copolymer, linear low density polyethylene, etc. Other thermoplastic resins such as the above and resin layers obtained by mixing recovered materials generated during the production of the laminated film can be used. Further, the intermediate layer (C) may be a resin layer having the same composition as the surface layer (A).

Furthermore, the intermediate layer (C) can be divided into two or more layers, and the total layer structure may be three or more layers.

The heat seal layer (B) may be a resin layer containing a 1-butene copolymer composed of 1-butene and other α-olefins. -It is preferable to use a 1-butene copolymer (b1) containing butene and propylene as essential components. Since the temperature range is wide and moderate heat seal strength can be easily obtained as an easy-to-open seal, the copolymer (b2) comprising the 1-butene copolymer (b1), propylene, and ethylene as essential components in a weight ratio (b1)/(b2) of 25/75 to 75/25, and the 1-butene copolymer used here (b1 ), those having a 1-butene-derived component content of 50 to 99 mol % are particularly preferable.

In addition, the heat seal layer (B) has a heat seal initiation temperature measured according to the heat seal initiation temperature test specified in JIS K-1713, which is lower than the heat seal initiation temperature of the surface layer (A). It is preferable because it facilitates the preparation of the food packaging bag and the easy-open sealing. For this reason, the laminated film (I) according to the present invention preferably has a heat-sealing initiation temperature difference of 30° C. or more between the surface layer (A) and the heat-sealing layer (B), especially 35 to 90° C. °C is particularly preferred.

The thickness of the laminated film (I) is usually 20-50 μm, preferably 25-40 μm.

When the laminated film (I) is a three-layer film formed by laminating (A) / (C) / (B) in the order of (A) / (C) / (B), the thickness ratio of the surface layer (A) and the intermediate layer (C) to the total thickness is The surface layer (A) is usually 10 to 50%, preferably 15 to 45%, and the intermediate layer (C) is usually 30 to 80%, preferably 40 to 70%. be.

The thickness of the heat seal layer (B) is preferably 1 μm or more and 8 μm or less, more preferably 2 μm or more and 7 μm or less, although it depends on the thickness of the laminated film (I).

Specific examples of the laminated film (I) include the following.
(i) A surface layer (A1) containing 75% by weight or more of a propylene-based copolymer consisting essentially of propylene and ethylene, and an intermediate layer (C1) containing 70% by weight or more of a propylene homopolymer. and a heat seal layer (B1) containing 25 to 75% by weight of a 1-butene copolymer containing 1-butene and propylene as essential components, (A1) / (C1) / (B1) Suitable for a bag having a thickness of 25 μm or 30 μm and having a gusset at the bottom (hereinafter referred to as a bottom gusset bag), which is laminated in order such that the average thickness ratio is 3:6:1. a three-layer film (I-1);
(ii) a surface layer (A2) containing 90% by weight or more of a propylene homopolymer; The intermediate layer (C2) and the heat seal layer (B1) are laminated in the order of (A2)/(C2)/(B1) so that the average thickness ratio is 2:7:1. or (iii) a propylene homopolymer and/or a propylene-based copolymer containing propylene and ethylene as essential components; A surface layer (A3) containing 80% by weight or more of a polymer, and an intermediate layer containing 70% by weight or more in total of linear low-density polyethylene, propylene, and a propylene-based copolymer containing ethylene as essential components. The layer (C3) and the heat seal layer (B1) are laminated in the order of (A3)/(C3)/(B1) such that the average thickness ratio is 3:6:1. , 25 μm or 30 μm in thickness and suitable for bottom gusset bags (I-3).

The laminate film (I) may be used as it is, but the surface layer (A) may be subjected to a corona discharge treatment in order to improve product appeal by printing. In each layer of the laminated film (I), antioxidants, slip agents, anti-blocking agents, anti-fogging agents, colorants, additives such as silica, etc., may be added as necessary within the scope of the present invention. It can be added as appropriate.

The method for producing the laminated film (I) is not particularly limited, but the co-extrusion molding method and the extrusion lamination method are particularly preferable, and the co-extrusion molding method is particularly preferable.

<Method for manufacturing and reinforcing food packaging bag>
A method for manufacturing a food packaging bag according to the present embodiment is a method for manufacturing a food packaging bag formed of a film, and includes a pair of fusion-cut seals on both sides in the width direction of a pair of main surface portions that are arranged to face each other. Forming a pair of reinforcing seal portions on at least part of the portion where the portion is formed; and Forming a pair of fusion seal portions on both width direction end portions of the pair of main surface portions.

FIGS. 6A to 6C are schematic diagrams showing an example of a method for manufacturing a food packaging bag according to this embodiment. In FIGS. 6A to 6C, a bottom gusset bag will be described as an example of a food packaging bag.
First, for example, on the main surface portion 11 and/or the main surface portion 12, which are composed of a three-layer laminated film, a pattern, characters, etc. are printed as necessary to form a printed portion (not shown), and then the heat seal layer is formed. The main surface portion 11 and the main surface portion 12 are arranged facing each other so as to be inside the bag, and the bottom gusset is sandwiched between the pair of main surface portions 11 and 12 so that the bottom gusset is folded inwardly of the bag ( FIG. 6(A)).

Next, a pair of reinforcing seal portions 15A and 16A are formed on both sides in the width direction of the pair of main surface portions 11 and 12 facing each other and where the pair of fusion seal portions are to be formed (FIG. 6B). )). In the present embodiment, in a later step, the pair of fusion seal portions 13 and 14 are arranged in a direction perpendicular to the width direction of the pair of main surface portions 11 and 12 (the direction from the opening 17 toward the bottom gusset 18). It is formed over the entire main surface portions 11 and 12 . Therefore, in this step, the pair of reinforcing seal portions 15A and 16A are formed over the entire pair of main surface portions 11 and 12 in the direction perpendicular to the width direction of the pair of main surface portions 11 and 12 .

At this time, it is preferable to thermally weld the pair of main surface portions 11 and 12 to form the pair of reinforcing seal portions 15A and 16A as a pair of thermally welded portions. Further, the heat sealing can be performed under the condition that the heat sealing strength is 10 to 20 N/15 mm, preferably 12 to 18 N/15 mm. The pair of reinforcing seal portions 15A and 16A can be formed by, for example, installing a known heat-sealing unit in a bag-making machine.

In this step, a reinforcing seal portion is formed at a portion 26' corresponding to a triangular vertex portion 26, which is an intersection point between the two widthwise folded ends 18a and 18b of the bottom gusset 18 and the fusion seal portion 13 formed in a later step. 15A is preferred. Similarly, it is preferable to form a reinforcing seal portion 16A at a portion 27' corresponding to the triangular vertex portion 27 on the fusion seal portion 14 side.

After that, a pair of fusion seal portions 13 and 14 are formed at both widthwise end portions of the pair of main surface portions 11 and 12 (FIG. 6C). In the present embodiment, as described above, the pair of fusion seal portions 13 and 14 are formed over the entire pair of main surface portions 11 and 12 in the direction orthogonal to the width direction of the pair of main surface portions 11 and 12. . At this time, the fusion seal strength between the widthwise ends of the pair of main surface portions 11 and 12 and the widthwise end of the bottom gusset 18 is 7.5 to 30 N/15 mm, preferably 12 to 30 N/15 mm. Temperature and bag-making speed can be adjusted. The pair of fusion-cut seal portions 13 and 14 can be formed by, for example, a bag-making machine.
Through the above steps, the bottom gusset bag as the food packaging bag 1A is formed.

As a step after forming the bottom gusset bag, the bottom gusset bag can be supplied to a filling machine according to the filling to be filled inside. For example, when the bottom gusset bag is filled with bread, the bottom gusset bag is supplied to an automatic bread filling machine, and after the bottom gusset bag is filled with bread, it is heat-sealed to form a bread packaging bag. At this time, heat-sealing can be performed under the conditions of easy opening and heat-sealing strength of 0.1 to 5 N/15 mm, preferably 0.2 to 3.5 N/15 mm. After that, if necessary, the easy-to-open seal portion (thermally welded portion) or the vicinity thereof above or below the upper portion of the bag, preferably the loaf of bread, is bound with a binding tool such as a plastic plate, tape, string, or the like.

In the present embodiment, the step of forming the pair of fused seal portions is performed after the step of forming the pair of reinforcing seal portions. The step of forming a pair of fusion seal portions may be performed together.

As described above, according to this embodiment, the food packaging bag 1A is formed inside the pair of fusion seal portions 13 and 14 with respect to the width direction of the pair of main surface portions 11 and 12, and the pair of fusion seal portions 13 are formed. , 14, the load applied to the pair of fusion seal portions 13 and 14 is reduced by the pair of reinforcement seal portions 15A and 16A, and the food packaging bag 1A is hard to tear, High reusability can be realized.

Further, when the food packaging bag 1A is a bottom gusset bag having a bottom gusset 18, the large opening 17 makes it easy to dispose of waste when reused as a garbage bag. In addition, when the food packaging bag 1A is a bread bag, it has a high deodorizing and moisture-proof effect, and when dust or the like is put therein, it is difficult for the smell to come out. Furthermore, by closing the opening 17 by forming a heat-sealed portion with a household heat sealer or the like, the deodorizing effect can be further enhanced. Therefore, it is useful as a substitute for garbage bags, and as a result, it is possible to promote reuse.

Furthermore, since the food packaging bag 1A has higher strength than conventional food packaging bags, it is difficult to break even if the food packaging bag 1A is subjected to a treatment such as washing. Therefore, the used food packaging bag 1A can be collected, subjected to sufficient cleaning treatment, sterilization treatment, etc., and reused as a food packaging bag.

Further, when the food packaging bag 1A is opened, the triangular vertex portions 26 and 27, which are the intersection points of the two widthwise folded end portions of the bottom gusset 18 and the fusion seal portions 13 and 14, are aligned with the reinforcing seal portions 15A and 16A. , the strength of the food packaging bag 1A can be further improved by reinforcing the triangular vertex parts 26, 27 to which the load is most applied when stuff is put in the bottom gusset bag.

Further, according to the present embodiment, a pair of reinforcements are provided on at least a part of the portions where the pair of fusion seal portions 13 and 14 are formed on both sides in the width direction of the pair of main surface portions 11 and 12 that are opposed to each other. Since the seal portions 15A and 16A are formed, and then the pair of fusion-cut seal portions 13 and 14 are formed at both ends in the width direction of the pair of main surface portions 11 and 12, the conventional method of manufacturing food packaging bags is greatly changed. It is possible to easily manufacture the food packaging bag 1A that is hard to tear without having to do so.

FIGS. 7A and 7B are schematic diagrams showing modifications of the range in which the fusion seal portion 13 of FIG. 4A and the reinforcing seal portion 15A of FIG. 4B are formed.
As shown in FIGS. 7A and 7B, the fusion seal portion 13 may be the same as in the above embodiment, and the reinforcing seal portion 15B may be formed in the bottom gusset 18 including the triangular vertex portion 26. By reinforcing the bottom gusset 18 to which a load is likely to be applied when stuff is put in the bottom gusset bag, the number of reinforced parts is reduced to realize simplification and simplification of the process, and the strength of the food packaging bag 1A. can be improved.

As another modification, as shown in FIGS. 8(A) and 8(B), the fusion seal portion 13 is the same as in the above embodiment, and the reinforcing seal portion 15C is formed only at the triangular vertex portion 26. may By reinforcing only the triangular vertex 26 to which the load is most likely to be applied when stuff is placed in the bottom gusset bag, the number of reinforced parts is reduced as much as possible to realize further simplification and simplification of the process. The strength of the packaging bag 1A can be improved.

Further, in the above-described embodiment, the reinforcing seal portion 15A extends over the entire fusion seal portion 14 along the extending direction of the fusion seal portion 14, but this is not restrictive. As shown in FIGS. 9A and 9B, the reinforcing seal portions 15D and 16D may be discontinuously formed along the extending direction of the fusion seal portion 13. As shown in FIGS. That is, a plurality of reinforcing seal portions 15d, 15d, . . . They may be arranged side by side along the existing direction. Also in this modified example, it is possible to improve the strength of the food packaging bag 1A while realizing simplification and simplification of the process by reducing the number of reinforced portions.

FIG. 10 is a plan view showing a modification of the food packaging bag 1A of FIG. 2(A). In FIG. 2A, the food packaging bag 1A is a bottom gusset bag, but the present invention is not limited to this, and the food packaging bag 1B may be a ship bottom bag. In this case also, as shown in FIG. 10, the food packaging bag 1B is formed inside the pair of fusion seal portions 13 and 14 with respect to the width direction of the pair of main surface portions 11 and 12. , 14 at least partially. As a result, the ship's bottom bag as the food packaging bag 1B is hard to break, and high reusability can be achieved.

Although the present embodiment has been described above, the present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

Examples of the present invention will be described below. The present invention is not limited to the examples shown below.

[Example 1]
As resin components for forming each layer of the surface layer, the intermediate layer and the heat seal layer, the following resins were used to prepare a resin mixture forming each layer. These mixtures are supplied to three extruders, respectively, and co-extruded so that the average thickness of each layer of the laminated film formed by the surface layer/intermediate layer/heat seal layer is 7 μm/18 μm/5 μm. A laminated film with a thickness of 30 μm was molded. Next, the printed layer of the obtained laminated film was subjected to corona discharge treatment so that the surface energy was 35 mN/m, to obtain a laminated film.
Surface layer: propylene-ethylene copolymer (ethylene-derived component content: 5.0% by mass, density: 0.90 g/cm ³ , MFR (measurement temperature: 230°C): 7 g/10 minutes) (hereinafter referred to as COPP (1) ) 90% by mass, ethylene-butene-rubber copolymer (density: 0.890 g/cm ³ , melting point 66° C., MFR (measurement temperature: 190° C.): 3 g/10 minutes) (hereinafter, EBR (1) called) 10% by mass
Intermediate layer: COPP (1) 15% by mass, propylene homopolymer (density: 0.90 g/cm ³ , MFR (measurement temperature: 230°C): 8 g/10 min) (hereinafter referred to as HOPP (1)) 75 % by mass, linear low-density polyethylene (density: 0.905 g/cm ³ , MFR (measurement temperature 190° C.): 4 g/10 min) (hereinafter referred to as LLDPE (1)) 10% by mass
Heat seal layer: COPP (1) 70% by mass, 1-butene-propylene copolymer (density: 0.90 g/cm ³ , MFR (measurement temperature: 230°C): 4 g/10 minutes) (hereinafter referred to as 1-butene system Copolymer (1)) 30% by weight

[Example 2]
A laminated film was obtained in the same manner as in Example 1, except that the resin components of the resin mixture used for the intermediate layer were as follows.
Intermediate layer: HOPP (1) 65 parts by mass, COPP (2) 10 parts by mass, LLDPE (1) 10 parts by mass, sugarcane-derived linear low-density polyethylene resin (density: 0.916 g/cm3, MFR=2. 3 g/10 min) (hereinafter referred to as bio-PE (1)) 15 parts by mass

Next, using a high-speed side-weld automatic bag making machine (manufactured by Totani Giken Kogyo Co., Ltd., device name "HK-40V"), bag making speed 140 bags / minute, reinforcement sealing temperature 160 ° C., fusion sealing temperature 300 ° C. A bottom gusset bag for loaf of bread was made from the obtained laminated film. At this time, the laminated film was folded into a predetermined shape so as to provide a bottom gusset, and then a pair of reinforcing seal portions and a pair of fusion sealing portions were formed on both sides of the folded structure.

[Comparative Example 1]
A bottom gusset bag was made from the laminated film in the same manner as in Example 1, except that only a pair of fusion seals were formed on both sides of the folding structure without forming a pair of reinforcing seals.

[Evaluation method]
(Bag breakage resistance at the fusion seal part when the bag is opened)
The opening of the bottom gusset bag obtained in Example 1, Example 2, and Comparative Example 1 was strongly expanded with both hands, and the operation was repeated 50 times. bottom. The number of tests was 10 (N=10). Table 1 shows the results.

(Bag breakage resistance at the triangular vertex)
The arm was put through the opening of the bottom gusset bag obtained in Example 1, Example 2 and Comparative Example 1, and the action of strongly pressing the fist against the bottom surface from the inside of the bag was repeated 50 times. It was tested whether or not a tear would occur in the The number of tests was 10 (N=10). Table 2 shows the results.

As shown in Table 1, in Example 1, no breakage was observed in the fusion-cut seal portion, and the bag breakage resistance at the fusion-cut seal portion was good. In addition, tearing occurred at the triangular vertices in 4 of the 10 tests, and the average number of operations at which the triangular apexes were torn was 44 times, demonstrating good bag breakage resistance at the triangular apexes. rice field.

Also, in Example 2, no tear was observed in the fusion-cut seal portion, and the bag breakage resistance at the fusion-cut seal portion was good. In addition, the triangular vertex was torn in 5 out of 10 tests, and the average number of operations in which the triangular vertex was torn was 43 times. rice field.

On the other hand, in Comparative Example 1, although no breakage was observed in the fused seal portion, breakage occurred at the triangular vertex portion in 7 out of 10 tests, and the average number of operations in which the triangular vertex portion was torn. was 18 times, and the bag breakage resistance at the triangular vertex was inferior.

1A Food packaging bag 1B Food packaging bag 11 Main surface 12 Main surface 13 Fusion seal 14 Fusion seal 15A Reinforcement seal 15B Reinforcement seal 15C Reinforcement seal 15d Reinforcement seal 15D Reinforcement seal 15E Reinforcement seal 16A Reinforcement Seal portion 16d Reinforcement seal portion 16D Reinforcement seal portion 16E Reinforcement seal portion 17 Opening 18 Bottom gusset 18a Width direction folding end 18b Width direction folding end 19 Printed portion 21 Bottom surface 22 First side surface 23 Second side surface 24 Third side surface 25 Fourth side face 26 Triangular vertex 27 Triangular vertex

Claims (10)

A food packaging bag formed of a film,
a pair of main surface portions facing each other in a flat bag state;
a pair of fusion seal portions formed at both ends in the width direction of the pair of main surface portions;
a pair of reinforcing seal portions formed inside the pair of fusion seal portions in the width direction of the pair of main surface portions to reinforce at least a portion of the pair of fusion seal portions;
A food packaging bag having further comprising a bottom gusset disposed on the opposite side of the opening of the pair of main surface portions and provided over the entire width direction of the pair of main surface portions;
the pair of fused seals extending from the opening to the bottom gusset;
2. The food packaging bag according to claim 1, wherein said pair of reinforcing seals are formed adjacent to said pair of fusion seals. 3. A triangular apex, which is an intersection of two width-direction folded end portions of the bottom gusset and the fusion seal portion, is reinforced with the reinforcing seal portion when the food packaging bag is opened. The food packaging bag described in . 2. The food packaging bag according to claim 1, wherein said reinforcing seal portion extends over the entirety of said fusion seal portion along the extending direction of said fusion seal portion. The food packaging bag according to any one of claims 1 to 4, wherein the reinforcing seal portion is a heat-sealed portion in which a pair of main surface portions are heat-sealed to each other. Any one of claims 1 to 5, wherein the film is a laminated film obtained by laminating a plurality of films made of one or more materials selected from olefin resins, biomass resins, and biodegradable resins. The food packaging bag described in the paragraph. 7. The food packaging bag according to claim 6, wherein the film is a laminated film obtained by laminating a plurality of films made of one or two of unstretched olefinic resin and biodegradable resin. The laminated film is
a surface layer (A) containing a propylene-based resin;
an intermediate layer (C) containing a propylene-based resin;
A 1-butene-based copolymer (b1) containing 1-butene and propylene as essential components and a copolymer (b2) containing propylene and ethylene as essential components, having a thickness of 1 μm or more and 8 μm or less. A heat seal layer (B) which is
The food packaging bag according to claim 6 or 7, having A method for producing a film-formed food packaging bag, comprising:
a step of forming a pair of reinforcing seal portions on at least a portion of portions where the pair of fusion seal portions are formed on both sides in the width direction of the pair of main surface portions that are opposed to each other;
a step of forming a pair of fusion seal portions at both ends in the width direction of the pair of main surface portions;
A method for manufacturing a food packaging bag. A method for reinforcing a film-formed food packaging bag having a pair of fusion-cut seal portions on both sides in the width direction of a pair of main surface portions opposed to each other in a flat bag state, wherein at least a part of the fusion-cut seal portion is A method of reinforcing a food packaging bag by reinforcing with a reinforcing seal.

Images