JP2017217764A - Packaging bag sealing method and packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably maintain sealability even when an amorphous polyester resin is used for a thermal fusion layer.SOLUTION: A packaging bag 1 is formed of a laminate film 4 having thermal fusion layers composed of amorphous polyester. A place where the thermal fusion layers are put on each other and joined together by heat sealing (primary heating) is subjected to secondary heating by a sealing method with a larger amount of heating than that of the heat sealing.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a packaging bag sealing method and a packaging bag.

It is contained in the contents as a packaging bag that encloses contents such as pharmaceuticals and quasi-drugs that contain active ingredients such as shipping drugs, or foods and cosmetics that contain fragrances and spices in the contents. There is a packaging bag that is highly required to reduce the amount of flavor, spice or active ingredient adsorbed on the bag and maintain the content of the flavor, spice or active ingredient in the contents at a desired value.
For this reason, a packaging bag may be formed by the laminated body using the heat sealing | fusion layer which has high non-adsorption performance as an innermost layer. As the non-adsorptive film used as the heat fusion layer, for example, a resin such as cyclic polyolefin, polyacrylonitrile, polyester copolymer or the like is used. However, since these resins are hard and brittle, it is difficult to obtain high sealing strength. Furthermore, since these resins are very expensive, even when they are provided in the heat-sealing layer, they must be thin. Therefore, it has been difficult to use these resins for a heat-sealing layer of a package requiring high sealing strength such as liquid packaging.

Patent Document 1 discloses a non-adsorptive sealant film comprising a base resin layer, an adhesive layer, and a heat-sealing layer (seal layer), and an amorphous polyester copolymer having a glass transition point of 70 to 90 ° C. A laminated body is disclosed in which a heat-sealing layer made of a polymer is laminated on a base resin layer via an adhesive layer by a dry laminating method.
In patent document 1, by making the sealing layer which consists of an amorphous polyester copolymer whose glass transition point is 70-90 degreeC into an innermost layer, it can achieve both the outstanding non-adsorbing property and sealing strength, The film formation is easy.

Japanese Patent Laying-Open No. 2015-66802

  In order to form a packaging bag using a laminate having an amorphous polyester-based resin as a heat-sealing layer, there are some problems due to the shape of the packaging bag. However, Patent Document 1 does not mention a problem caused by the shape of the packaging bag.

  Here, examples of the shape of the packaging bag include a four-sided bag, a three-sided bag, a jointed bag, and a gusset bag such as a standing bag.

Among these, the palm bag and the standing bag have a portion where the laminated body is overlapped twice (four sheets) or more to form a step portion by folding the laminated body in the formation process. For example, the step portion of the standing bag is a portion where the bottom gusset portion is folded and joined to the bag body. Further, the step portion of the palm bag is a portion where the lower or upper heat seal region overlaps with the back sticking.
Since the stepped portion as described above is likely to form a fine tunnel-shaped gap, leakage may occur from the stepped portion, which may affect the sealing performance of the packaging bag. For this reason, conventionally, the sealing portion was more reliably provided with a sealing bag by re-sealing the stepped portion and filling it with remelted resin.

However, when amorphous polyester is used as the heat-sealing layer, when the amorphous polyester is crystallized by the first heat sealing, it is difficult to re-melt by heat sealing again. For this reason, it becomes difficult to re-melt the step part mentioned above by a second heat seal, and to improve a sealing performance.
Therefore, many of the packaging bags using amorphous polyester as the heat-sealing layer are formed as four-sided bags, and packaging bags that have a step difference such as a palm bag or a standing bag are not used.

  The present invention has been made in view of such circumstances, and even when an amorphous polyester-based resin is used for the heat-sealing layer, the sealing of the packaging bag that can maintain the sealing property more reliably. The object is to provide a method and packaging bag.

  In order to solve the above problems, the packaging bag sealing method and the packaging bag of the present invention employ the following means.

  The sealing method for a packaging bag according to the first aspect of the present invention is a sealing method for a packaging bag formed of a laminate having a heat-sealing layer using amorphous polyester, wherein the heat-sealing layers are The first step of superimposing and joining by heat sealing, and the step formed by further overlapping the two laminates joined by the first step, a seal having a larger heating amount than the heat sealing A second step of melting by the method.

Heat-sealing (also referred to as primary heating or primary sealing) a heat-sealing layer using amorphous polyester, and then re-melting by heat sealing (also referred to as secondary heating or secondary sealing). It is difficult.
The place where such remelting is performed is a step portion formed by further overlapping two laminated bodies joined by heat sealing. The remelting of the stepped portion is performed in order to prevent leakage from the stepped portion and improve the sealing performance of the packaging bag more reliably.

  So, according to this structure, the sealing method with a larger heating amount than a heat seal is performed as a secondary heating with respect to the said level | step-difference part. As a result, the heat-sealing layer using amorphous polyester can be re-melted by secondary heating, so that even if an amorphous polyester-based resin is used for the heat-sealing layer, the sealing property is more reliably maintained. Can do.

  In the first aspect, the sealing method may be an ultrasonic seal or a high frequency dielectric seal.

  According to this configuration, the heat-sealing layer using amorphous polyester can be self-heated and easily subjected to secondary heating.

  In the first aspect, the crystallinity of the amorphous polyester may be 0 to 20%.

  The packaging bag which concerns on the 2nd aspect of this invention is manufactured by the sealing method of the said description.

  According to the present invention, even when an amorphous polyester-based resin is used for the heat-sealing layer, it has an excellent effect that the sealing performance can be more reliably maintained.

1 is a schematic external view of a standing bag according to an embodiment of the present invention. It is a block diagram of the laminated film which forms the standing bag which concerns on embodiment of this invention. It is a side surface enlarged view of the level | step-difference part of the standing bag which concerns on embodiment of this invention. It is a general | schematic external view of the palm bag which concerns on embodiment of this invention. It is a side surface enlarged view of the level | step-difference part of the palm bag which concerns on embodiment of this invention.

  Hereinafter, embodiments of a packaging bag sealing method and a packaging bag according to the present invention will be described with reference to the drawings.

[First Embodiment]
The first embodiment of the present invention will be described below.

FIG. 1 is a schematic external view of a standing bag 1 which is an example of a packaging bag according to this embodiment. FIG. 1 (A) is a front view of the standing bag 1 and FIG. 1 (B) is a perspective view of a bottom gusset portion 2. FIG.
The standing bag 1 according to the first embodiment shown in FIG. 1 includes a pair of opposed flat portions 3A and 3B, and a bottom gusset portion 2 that is folded inward of the bag as a gusset portion at the bottom of the flat portions 3A and 3B. It is a self-supporting gusset bag.

  The pair of flat portions 3A and 3B and the bottom gusset portion 2 are formed of a laminated film 4 that is a film-like laminate formed of a resin having a multilayer structure. A region indicated by hatching in the lower portion 5 and the side portions 6 and 6 of the standing bag 1 shown in FIG. 1A is a region where the laminated film 4 forming the standing bag 1 is joined by heat sealing.

  When the bottom gusset portion 2 is joined to the pair of plane portions 3A and 3B, the outer surface layer is formed by the heat-resistant base material layer 10 (see FIG. 2). 10) If they are normal, they are not joined.

  Therefore, when the bottom gusset portion 2 and the flat portions 3A and 3B are joined by cutting off a part of the side portion of the bottom gusset portion 2, the inner surface layers of the flat portions 3A and 3B are connected to each other through the cut portion 7. Are joined. Thereby, plane part 3A, 3B is integrated, it prevents that a bottom opens in the side part of the standing bag 1, and the self-supporting function of the standing bag 1 is expressed.

  The standing bag 1 is sealed by heat sealing or the like after the contents such as medicines, foods, and chemicals are stored.

FIG. 2 is a configuration diagram of the laminated film 4 forming the standing bag 1.
As shown in FIG. 2, the laminated film 4 is formed by laminating a base material layer 10 which is an outer surface layer having heat resistance and a heat fusion layer 12 which is an inner surface layer having heat fusibility. An intermediate layer 11 is laminated between the wearing layer 12 and the base material layer 10. Note that the laminated film 4 may not have the intermediate layer 11.

As a film used as the base material layer 10, a film having good mechanical suitability and printability is preferable. For example, films made of synthetic resins such as polyethylene terephthalate (polyester), polyamide (nylon), polypropylene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polycarbonate, and polyacetal, or films obtained by co-extrusion of these synthetic resins Or paper.
These films may be unstretched films or stretched films stretched in a uniaxial direction or a biaxial direction.
As the base material layer 10 of the laminated film 4 forming the standing bag 1 according to the present embodiment, as will be described in detail later, in particular, polyethylene terephthalate from the point of suitability for fusion to the step portion 20 at a high temperature during bag making. (Polyester) is suitable.
In addition, the thickness of the base material layer 10 is 6-60 micrometers, More preferably, 9 micrometers-50 micrometers are preferable.
Moreover, as a film used for the base material layer 10, a vapor deposition film provided with a vapor deposition layer may be used. Examples of the vapor deposition layer include inorganic substances such as aluminum, silicon oxide, aluminum oxide, indium oxide, tin oxide, zirconium oxide, and magnesium oxide.

As the film or the like used as the intermediate layer 11, a material having barrier performance is preferably used from the viewpoint of protecting the contents. The barrier performance includes light shielding from visible rays and ultraviolet rays, and gas barrier properties such as oxygen and water vapor. Among these barrier performances, a material having an appropriate function is used as the intermediate layer 11.
Examples of the material having barrier properties include metal foils such as aluminum, iron, copper, and tin, polyethylene terephthalate (polyester), polyamide (nylon), polyvinyl chloride, polycarbonate, polyvinyl alcohol, and ethylene-vinyl acetate copolymer. Films such as fluoride, films coated with polyvinylidene chloride on these films, films deposited with inorganic substances such as aluminum, silicon oxide, aluminum oxide, indium oxide, tin oxide, zirconium oxide, magnesium oxide, films such as polyvinylidene chloride Moreover, the nonwoven fabric and foam film which have heat insulation are mentioned.
In addition, the functions of the intermediate layer 11 are not limited to these, and include gas barrier properties, mechanical toughness, flex resistance, puncture resistance, impact resistance, wear resistance, cold resistance, heat resistance, chemical resistance It can be appropriately selected according to the required function such as the property.
The film used as the intermediate layer 11 may be an unstretched film or a stretched film stretched in a uniaxial direction or a biaxial direction. Furthermore, the intermediate layer 11 may be not only one layer but also two or more layers.

  The film used as the heat-sealing layer 12 is made of amorphous polyethylene terephthalate (hereinafter also referred to as “amorphous polyester”) as a fusing material, and crystallinity is controlled to impart heat-fusibility. Is.

Amorphous polyester is a film made of a composition comprising polyester, softening agent, binder and molding aid, and crystallinity falls within a predetermined range by rapid cooling during film formation. Be controlled. In this way, the amorphous polyester is imparted with heat-fusibility by controlling the crystallinity. And by making amorphous polyester into a non-adsorptive film, unlike other non-adsorptive films in which a non-adsorptive layer and a thermal fusion layer are laminated, the whole film (layer) is thermally fused. Therefore, it becomes possible to obtain higher sealing strength.
More specifically, the amorphous polyester is, for example, 0.1 to 3 parts by weight of styrene-methyl (meth) acrylate-glycidyl methacrylate copolymer, cyclohexanedimethanol-ethylene with respect to 100 parts by weight of polyethylene terephthalate. A polyethylene terephthalate resin composition comprising 3 to 20 parts by weight of a glycol-terephthalic acid condensation polymer (PCTG) and 0.05 to 1.5 parts by weight of calcium stearate. The intrinsic viscosity of polyethylene terephthalate is 0.6 to 0.8 dl / g. The epoxy value of the styrene-methyl (meth) acrylate-glycidyl methacrylate copolymer is 0.5 to 4.0 meq / g.

Furthermore, the range of the degree of crystallinity of the amorphous polyester is preferably 0 to 20%, more preferably 0 to 18%.
The crystallinity is calculated by dividing the heat of fusion when the amorphous polyester is melted by the heat of fusion of the complete crystal (140 J / g for PET resin) using a differential scanning calorimetry (DSC). It is calculated by multiplying the value obtained by 100.

  In addition, the said composition of the heat-fusion layer 12 is an example, and if the amorphous polyester is used for the heat-fusion layer 12, and it has high non-adsorption performance, it will not restrict to this.

As a method of laminating the base material layer 10, the intermediate layer 11, and the heat sealing layer 12, a conventionally known laminating method such as a dry laminating method, an extrusion laminating method, a non-solvent laminating method, or a thermal laminating method can be applied. Accordingly, a plurality of lamination methods may be combined.
However, since the heat-sealable layer 12 according to this embodiment is a film to which heat-sealability is imparted by controlling the crystallinity of the amorphous polyester, it is heat-sealable when heat is applied in the lamination process. May be affected. For this reason, the laminating method according to this embodiment is preferably a laminating method that does not crystallize the amorphous polyester, such as a dry laminating method or a non-solvent laminating method.

  Here, at the portions (region A in FIG. 1) where the bottom gusset portion 2 is folded at both side portions 6 and 6 of the standing bag 1, a plurality of laminated films 4 are overlapped to cause a step.

FIG. 3 is an enlarged side view of region A. FIG.
As shown in FIG. 3, in the region A, the plane portion 3 </ b> A and the bottom gusset portion 2 overlap with the plane portion 3 </ b> B and the bottom gusset portion 2.
That is, in the region where the bottom gusset portion 2 is not folded (the left side in FIG. 3), the two laminated films 4 of the flat portion 3A and the flat portion 3B overlap, while the bottom gusset portion 2 is folded (see FIG. 3). On the right side, a total of four laminated films 4 overlap. Accordingly, a stepped portion 20 (hereinafter also referred to as “gusset intersection”) is formed at the boundary between the region where the two laminated films 4 overlap and the region where the four laminated films 4 overlap.

  As described above, the stepped portion 20 is a step formed by further overlapping the two laminated films 4 joined by heat-sealing the heat sealing layers 12 to each other. Moreover, the level | step difference part 20 is a level | step difference which arises in the boundary in which the frequency | count that the laminated | multilayer film 4 overlaps in other words differs.

The step portion 20 is liable to form a fine tunnel-shaped gap, and may affect the sealing performance of the standing bag 1. For this reason, it is necessary to fill the gap by remelting the heat-sealing layer 12 with respect to the stepped portion 20 and to provide the sealing property more reliably.
However, since the amorphous polyester is used for the heat sealing layer 12 according to the present embodiment, it is difficult to perform heat sealing again and remelt after heat sealing.

  The reason why it is difficult to remelt the amorphous polyester is that the crystallinity of the amorphous polyester is increased by primary heating (hereinafter also referred to as “primary seal”). Since the crystallized polyester has a melting point of about 250 ° C., it can be remelted by heating at a temperature exceeding this melting point. However, when the seal part formed of amorphous polyester is heated at a high temperature exceeding 250 ° C., other layers such as a base material layer laminated on the seal part are melted. As a result, the appearance of the packaging bag is deteriorated, and further, the function as the packaging bag may be impaired. In general, when primary sealing is performed, the degree of crystallinity of the amorphous polyester exceeds 20%, and when the degree of crystallinity exceeds 20%, remelting by heat sealing (hereinafter referred to as “secondary heating”, It is also called “secondary seal”.

  Therefore, in the packaging bag sealing method according to the present embodiment, first, heat sealing layers 12 using amorphous polyester are overlapped with each other and heat sealed (heating temperature 100 to 200 ° C., heating time 0.1 to 2). The primary heating process for joining is performed. And the sealing method which concerns on this embodiment fuse | melts the level | step-difference part 20 formed when the laminated | multilayer film 4 joined by the primary heating process is further piled up by the sealing method which produces the heating amount larger than heat sealing. A secondary heating step for (re-fusion) is performed.

  Examples of the sealing method include a method of self-heating by frictional heat, high-frequency dielectric heating or the like without heating the heat sealing layer 12 from the outside as in heat sealing, for example, ultrasonic sealing or high-frequency dielectric sealing. Applies.

Heat sealing is a method in which a heated hot plate is pressed against a laminated film and welded by heat conduction.
The ultrasonic seal is a method in which a laminated film is mechanically vibrated 20 to 40,000 times per second by using an ultrasonic oscillator, a vibrator that converts ultrasonic waves into longitudinal vibrations, and a resonator horn, and is self-heated and welded. It is.
The high-frequency dielectric seal is a method in which a resin serving as a dielectric is placed in a high-frequency electric field formed between two electrodes and self-heats due to dielectric loss (friction caused by rotation of the dielectric itself).
The ultrasonic sealing method and the high-frequency dielectric sealing method generate internal heat, not external heat, and heating is uniform.

  In the following description, a case where an ultrasonic seal is applied as the secondary seal will be described.

In the secondary heating process according to the present embodiment, intersection processing is performed in which a region including the step portion 20 (hereinafter referred to as “intersection processing region”) B is re-fused by ultrasonic sealing.
This secondary seal heats the intersection processing region B in a range that does not protrude from the inner edge of at least the primary sealed region. If the secondary sealed area is flush with or protrudes from the inner edge of the primary sealed area, not only will the appearance of the sealed area deteriorate, but if the area is stressed, the edge of this area ( There is a possibility that the seal portion will be damaged starting from the seal edge.

  Even if the amorphous polyester of the heat-sealing layer 12 is crystallized by the intersection treatment using the ultrasonic seal, the crystallized polyester itself is remelted by frictional heat, and a fine tunnel shape generated in the step portion 20 is obtained. The gap is filled with remelted polyester. Thereby, the leak from the level | step-difference part 20 is prevented and the sealing performance of the standing bag 1 is improved.

In addition, the intersection process area | region B is an area | region including the level | step-difference part 20, and is in the area | region range heat-sealed by the primary seal | sticker. Further, in the intersection processing region B, as in the rectangle shown in FIG. 1, a seal mark generated by ultrasonically sealing the intersection processing region B between the ultrasonic sealing machine and the base remains.
In addition, since the shape of the intersection processing area B is a seal mark, the shape is not limited to a rectangle, and may be another shape such as a polygon, a circle, an oval, or an ellipse.

  Next, with reference to FIGS. 4 and 5, an example in which the intersection bag process is performed with the packaging bag as the jointed bag 40 will be described.

  FIG. 4 is a schematic external view of the palm bag 40. FIG. 5 is an enlarged side view of the step portion 20 of the palm bag 40.

  The joint-bag 40 is a packaging bag formed by overlapping the ends of a single laminated film 4. The joint bag 40 includes a top seal portion 41 formed at the upper end portion, a bottom seal portion 42 formed at the lower end portion, and a back pasting portion 43 formed from the top seal portion 41 to the bottom seal portion 42.

As an example, the laminated bag 4 is folded into a cylindrical shape, the left and right end portions are overlapped, and the heat-sealing layers 12 are joined together by heat sealing to form the back pasting portion 43. . Thereafter, the top seal portion 41 and the bottom seal portion 42 are heat-sealed, whereby the joint bag 40 is formed. These heat seals are primary seals.
Thereby, by bending the back pasting portion 43 with respect to the top seal portion 41 and the bottom seal portion 42, as shown in FIG. 5, the boundary between the back pasting portion 43 and the top seal portion 41, the back pasting portion 43 and the bottom A step portion 20 is formed at the boundary with the seal portion 42.

  Therefore, ultrasonic sealing is performed on the intersection processing region B including the stepped portion 20 as a secondary seal, and fine tunnel-shaped gaps generated in the stepped portion 20 are filled with remelted polyester. Thereby, the leak from the level | step-difference part 20 is prevented and the sealing performance of the joint bag 40 is improved.

Note that, in the present embodiment, the bag-making joint bag 40 is supplied to a user who fills the contents. In this case, the joint bag 40 is supplied to the user with either the top seal portion 41 or the bottom seal portion 42 opened, and after the user fills the contents from the opening, the opening is heat sealed and sealed. To do. And the intersection process is performed with respect to the intersection process area | region B by the user, after the opening part is heat-sealed.
In addition, the intersection processing region is not limited to this, and the user himself / herself makes the joint bag 40 without filling the bag-making joint bag 40, and after the contents are filled in a series of processes for making the bag. Intersection processing may be performed on B.

  As described above, the packaging bag according to the present embodiment is formed of the laminated film 4 having the heat fusion layer 12 using amorphous polyester. And the sealing method with a larger heating amount than a heat seal is performed as a secondary seal with respect to the location where the heat-sealing layers 12 are overlapped and joined by heat seal (primary seal). As a result, the heat-sealing layer 12 using amorphous polyester can be re-melted by the secondary seal, so even if amorphous polyester is used for the heat-sealing layer 12 as a packaging bag, the sealing performance is more reliably ensured. Can keep.

  In addition, although this embodiment demonstrated the form which performs secondary sealing with respect to the level | step-difference part 20, this invention is not limited to this, The heat-fusion layer 12 using amorphous polyester is provided. If there is a need for remelting, a secondary seal may be performed on a region where there is no stepped portion 20.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, comparative examples, and reference examples, but the present invention is not limited to the following examples.

  The laminated film 4 used in Examples, Comparative Examples, and Reference Examples has a base layer 10 made of polyamide (nylon), an intermediate layer 11 made of polyethylene terephthalate (polyester) on which aluminum oxide is deposited, and a heat fusion layer. 12 is composed of the above-described polyethylene terephthalate resin composition (amorphous polyester). In Reference Example 3 only, the thermal fusion layer 12 was made of linear low density polyethylene (LLDPE).

Further, in Example 1, the bag-making shape formed by heat sealing (sealing temperature: 140 ° C., sealing time: 0.5 seconds) is the palm bag 40, and the intersection processing for the step portion 20 (intersection processing region B) is super. Sonic sealing was performed. In Example 2, the bag-making shape was the standing bag 1, and ultrasonic sealing was performed as an intersection process for the step portion 20 (intersection process region B) of the bottom gusset part 2.
The ultrasonic oscillator used when performing ultrasonic sealing is an iQ series servo-controlled ultrasonic plastic welding machine manufactured by Dukane Japan. The fusion conditions by the ultrasonic seal are that the transmission frequency is 30 kHz, the applied pressure is 210 N, and the pressurization time is 0.5 seconds.
In addition, the apparatus used for an ultrasonic seal is not restricted above. Also, the fusion condition of the ultrasonic seal is an example. If the transmission frequency is 20 to 40 kHz, the applied pressure is 20 to 800 N, and the pressurization time is within the range of 0.1 to 20 seconds, the stable adhesive strength is obtained. can get.

In Example 3, the bag-making shape formed by heat sealing (sealing temperature: 140 ° C., sealing time: 0.5 seconds) is the palm bag 40, and the high-frequency dielectric seal is used as the intersection processing for the step portion 20 (intersection processing region B). Went. In Example 4, the bag-making shape was the standing bag 1, and high-frequency dielectric sealing was performed as an intersection process for the step portion 20 (intersection process region B) of the bottom gusset part 2.
The high-frequency oscillation device used when performing high-frequency dielectric sealing is a high-frequency welder manufactured by Yamamoto Vinita Co., Ltd. The fusion condition by the high frequency dielectric seal is that the transmission frequency is 40.46 kHz, the applied pressure is 500 N, and the pressurizing time is 1.0 second.
In addition, the apparatus used for a high frequency dielectric seal is not restricted above. The fusion condition of the high-frequency dielectric seal is also an example. If the transmission frequency is 20 to 60 kHz, the applied pressure is 10 to 2500 N, and the pressurization time is within the range of 0.8 to 30 seconds, stable adhesive strength is obtained. can get.
In Examples 3 and 4, the joint bag 40 or the standing bag 1 that has already been formed is filled with a leaking liquid, which will be described later, in another process, and then the opening is heat-sealed to perform intersection processing. ing.

  In the comparative example and the reference example, the bag-making shape formed by heat sealing (sealing temperature: 140 ° C., sealing time: 0.5 seconds) is the four-sided bag, the joint bag 40, and the standing bag 1, and the joint bag 40 and the standing bag are formed. The intersection process of the bag 1 was heat sealing. On the other hand, since the four-sided bags of Reference Examples 1 and 2 have no intersection, no intersection processing is performed.

  The sealability evaluation test was a submergence test (leakage test) in which the packaging bag according to the example or the comparative example was submerged, and a leak liquid test in which a leak liquid was sealed.

  The leakage test was performed based on method A of JIS-Z0238. Specifically, after the packaging bag was submerged in the vacuum chamber, the vacuum chamber was depressurized and held for 1 minute, and the ultimate vacuum (differential pressure from atmospheric pressure) was obtained as a result. That is, in the sealing evaluation test, in the following table, when the pressure is 450 mmHg, it is determined that the sealing property of the packaging bag is maintained, and when the pressure is 220 mmHg, it is determined that the sealing property of the packaging bag is low. did.

The leak liquid test was performed using an AGELESS seal check spray manufactured by Mitsubishi Gas Chemical Company, Inc. When the check liquid (leak liquid) is sprayed from the ageless seal check spray into the inside of the packaging bag and the check liquid penetrates from the sealing portion of the packaging bag, the sealing portion is determined to be defective.
As an example of the evaluation criteria for the leak liquid test, when the check liquid does not penetrate into the seal part, it is evaluated that there is no liquid leak and the check liquid penetrates into the seal part. It is evaluated that there is seal receding when there is no penetration in the width direction of the part but there is no liquid leakage, and it is evaluated that there is liquid leakage when the check liquid penetrates the width direction of the sealing part. In addition, the result of the leak liquid test in the following table determines whether or not the check liquid has permeated into the seal portion subjected to the intersection process, and when it does not permeate, it is determined that the sealing performance of the packaging bag is maintained.

  Table 1 shows the test results of Example 1, and Table 2 shows the test results of the comparative example and the reference example.

As shown in Table 1, the joint bag 40 (Example 1) and the standing bag 1 (Example 2) subjected to ultrasonic sealing as the intersection process are sealed in the packaging bag in both the leak test and the leak liquid test. It was confirmed that the sex was maintained. On the other hand, the joint bag 40 (Comparative Example 1) and the standing bag 1 (Comparative Example 2), in which the heat fusion layer 12 is made of a polyethylene terephthalate resin composition (amorphous polyester) and the intersection treatment is performed by heat sealing, are leak tests. In both of the leak test and the leak test, the sealing performance of the packaging bag is not maintained.
Further, the joint bag 40 (Example 3) and the standing bag 1 (Example 4), which have been subjected to high-frequency dielectric sealing as the intersection process, maintain the sealing performance of the packaging bag in both the leak test and the leak liquid test. I was able to confirm.

Note that the four-sided bags of Reference Examples 1 and 2 are heat sealing and impulse sealing, respectively. However, since the intersection process is not required, the sealing performance of the packaging bag in both the leak test and the leak liquid test. Is maintained. Impulse sealing is a method in which welding is performed by heat generated by applying a large current to a nichrome ribbon heater instantaneously after being pressed onto a film.
Further, in the standing bag 1 in which the heat-sealing layer 12 of Reference Example 3 is LLDPE, re-heating by heat-sealing using heat sealing is sufficient as an intersection process for filling the gap of the stepped portion 20, and leakage tests and In any of the leak liquid tests, the sealing performance of the packaging bag is maintained.

  That is, even in a packaging bag in which the heat-sealing layer 12 is amorphous polyester, as shown in Examples 1 to 4, the heat-sealing layer is made into LLDPE by performing ultrasonic sealing or high-frequency dielectric sealing as intersection processing. It was confirmed that the same high sealing performance as that of a standing bag or a four-sided bag subjected to heat sealing as the intersection treatment was obtained.

  As mentioned above, although this invention was demonstrated using the said embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which the changes or improvements are added are also included in the technical scope of the present invention. Moreover, you may combine the said embodiment suitably.

1 Standing bag (packaging bag)
4 Laminated film (laminate)
12 Heat-seal layer 20 Step part 40 Jointed bag (packaging bag)

Claims (4)

A method for sealing a packaging bag formed of a laminate having a heat-sealing layer using amorphous polyester,
A first step in which the heat-sealing layers are overlapped and joined by heat sealing;
A second step of melting the stepped portion formed by further overlapping the two laminated bodies joined in the first step by a sealing method having a heating amount larger than that of the heat seal;
A packaging bag sealing method comprising:   3. The packaging bag sealing method according to claim 1, wherein the sealing method according to the second step is an ultrasonic seal or a high frequency dielectric seal.   The method for sealing a packaging bag according to claim 1 or 2, wherein the degree of crystallinity of the amorphous polyester is 0 to 20%.   The packaging bag manufactured by the sealing method of any one of Claims 1-3.

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