JP6719258B2 - Laminated film - Google Patents

Description

The present invention relates to a laminated film.

Conventionally, a laminated film made of various materials has been proposed as a pouch for filling and packaging liquids such as foods, seasonings, pharmaceuticals, supplements, viscous materials, or powders.

For example, Patent Document 1 states that the barrier performance of a conventionally known package is still insufficient, and further a coating film having a gas barrier property is further formed on the inorganic oxide vapor deposition film on the base film by using the sol-gel method. It is described that good barrier performance can be achieved by providing the same.

Patent Document 2 uses a film in which a base material layer, an easy-tear layer, an intermediate layer, and a heat-sealing layer are laminated in this order, focusing on the tearing property (hand-cutting property or easy-opening property) when the packaging bag is opened. It is described that when the biaxially stretched polyamide resin film is used as the easily tearable layer in the package, good unsealing property is exhibited.

JP, 2005-145492, A JP, 2003-236972, A

In addition to the barrier property and the easy-open property mentioned above, the filling package is required to have various functions based on manufacturing requirements, display convenience at the time of sale, and the like.

For example, when a filled package is manufactured, contents are often attached to the seal portion. In particular, when so-called "bag-filling" is performed in which a package is manufactured while filling the contents, it is inevitable that the contents adhere to the seal portion. Therefore, the bag-making material used for bag-filling is required to have "contamination-sealing property" or "contamination-sealing property" that exhibits high sealing performance even if contents (contamination) adhere to the seal portion. ..

The seal of the package is generally a heat seal. However, heat sealing generally requires a process time of several seconds per bag (1 to 3 seconds in a typical foreign substance seal), and the speed cannot be said to be sufficiently high. In this respect, in the case of an ultrasonic seal that seals by applying ultrasonic waves, the process time per bag is less than 1 second (for example, 0.1 to 0.5 seconds). Therefore, in order to shorten the bag-making process time, a bag-making material having a good sealing property when ultrasonic sealing is adopted is required.

Furthermore, when selling a filled package in a retail store, there is a demand for placing the package in an upright state on a product display shelf so that the consumer can easily visually recognize and recognize the product design. Therefore, it is preferable that the bag-making material has sufficient self-supporting property (standing performance) to endure display when the bottom part is gusseted and placed in an upright state.

The above-mentioned Patent Documents 1 and 2 describe that the sealing method may be ultrasonic sealing and that the form of the package may be a standing pouch. However, in these patent documents, the above is generally described only as the applicability of the bag-making material, and when the bag-making material is made of any material and has any configuration, No studies have been made as to whether or not the performance of s. Further, these patent documents do not make any mention of the foreign matter sealing property.

The present invention has been made in view of the above situation, and an object thereof is to provide a bag-making material for producing a filled package having excellent foreign matter sealing properties when an ultrasonic seal is adopted. And preferably to provide a bag-making material for producing a filled package having comfortable hand-cutting property and good self-supporting property.

The present invention is summarized as follows.

[1] having an outer layer and a sealant layer,
A laminated film, wherein the sealant layer is a layer made of a thermoplastic resin having a tensile elastic modulus of 200 MPa or more and 500 MPa or less and having a film thickness of 10 μm or more and 50 μm or less.

[2] In [1], further comprising a barrier layer and an easy-tear layer between the outer layer and the sealant layer, wherein the sealant layer and the easy-tear layer are adjacent to each other with or without an adhesive. The laminated film described.

[3] The laminated film according to [2], which has a total film thickness of 50 μm or more and 100 μm or less and a tear strength of less than 0.6 N.

[4] The easily tearable layer is a layer formed of a uniaxially stretched film or a biaxially stretched film of a resin selected from polyester, polyamide, and polyolefin,
The laminated film according to [2] or [3], wherein the sealant layer is a layer made of LLDPE.

[5] The laminated film as described in any one of [1] to [4], which is used for bag-making filling involving a contaminant sealing step by ultrasonic waves.

[6] A bag manufacturing method comprising a step of ultrasonically sealing the sealant layers of the laminated film according to any one of [1] to [4].

[7] The bag making method according to [6], wherein the ultrasonic sealing step is an ultrasonic foreign material sealing step.

The laminated film of the present invention can exhibit a good sealing property when an ultrasonic seal is adopted, and can produce a filled package having excellent foreign substance sealing property. The filled package obtained from the laminated film of the preferred embodiment of the present invention further exhibits additional properties such as good hand tearability and good self-supporting property.

FIG. 1 is a schematic sectional view showing the structure of a laminated film in a preferred embodiment of the present invention. FIG. 2 is an explanatory diagram showing the procedure of the bag-making filling process in Examples 1 to 3 and Comparative Example 1.

Hereinafter, the present invention will be described in detail.

The laminated film of the present invention has an outer layer and a sealant layer,
The sealant layer is a layer made of a thermoplastic resin having a tensile elastic modulus of 200 MPa or more and 500 MPa or less and having a film thickness of 10 μm or more and 50 μm or less. The laminated film in a preferred embodiment of the present invention further has a barrier layer and an easily tearable layer between the outer layer and the sealant layer, and the sealant layer and the easily tearable layer are adjacent to each other with or without an adhesive. ing. Here, the direct contact between the sealant layer and the easily tearable layer is not a requirement of the present invention. It is within the scope of the present invention to interpose between these layers a layer made of an adhesive usually used in the art for fixing these layers to each other. Examples of the case where both layers are in direct contact with each other without an adhesive agent interposed therebetween include, for example, a case where the interfaces of both layers are fused.

That is, the laminated film of the present invention in the above preferred embodiment is shown in FIG. The laminated film of FIG. 1 has an outer layer 1, a barrier layer 3, an easily tearable layer 4, and a sealant layer 2 in this order, and the sealant layer 2 has the above-mentioned film thickness and tensile elastic modulus. is there. Each of these layers can be adjacent to each other with or without an adhesive between each layer.

The present invention, as described above, is made in view of the fact that good sealing properties are not realized when the laminated film conventionally known for heat sealing is diverted to ultrasonic sealing as it is, and ultrasonic sealing is performed. The present invention provides a laminated film as a suitable bag-making material.

In heat sealing, the sealant layer is melted by heat, and the melted material is fused at the interface between the sealant layers to form a seal. Therefore, a material that is relatively soft and easy to fuse is selected as a material for forming the sealant layer. In addition, it is expected that the larger the range of fusion of the melted material in the thickness direction of the material, the stronger the sealing property, and therefore the thickness of the sealant layer is designed to be relatively thick. Generally, for example, a thickness of about 100 μm is adopted.

On the other hand, the ultrasonic seal forms a seal by vibrating the sealant layer by applying an ultrasonic wave, melting the sealant layer by frictional heat between adjacent sealant layers, and fusing the two together. However, it has been found that if a contaminant film is ultrasonically sealed using a conventionally known laminated film for ultrasonic sealing, sufficient sealing performance cannot be obtained.

The present inventors have studied in detail the above phenomenon, in the case of contaminant sealing by ultrasonic waves, the presence of contaminants between the sealant layers during sealing makes it difficult for friction between sealant layers to occur, and it is soft. It has been found that, in combination with the fact that vibration is absorbed and attenuated by the thick and thick sealant layer, sufficient sealing performance cannot be obtained.

Therefore, in the present invention, a thin layer made of a relatively hard material is arranged as a sealant layer suitable for foreign matter sealing by ultrasonic waves, and by effectively utilizing the vibration generated by ultrasonic waves, good sealing property is obtained. Is realized.

Here, the thin thickness of the sealant layer also brings about a result that the hand tearability at the time of opening the package is improved.

Further, since the laminated film having the sealant layer of the constitution of the present invention exhibits an extremely high degree of foreign matter sealing property, the application of ultrasonic waves for obtaining a good seal is sufficient for a very short time, and therefore, the contents of the package. It has become possible to reduce the influence of ultrasonic waves on the noise.

Hereinafter, each layer of the laminated film of the present invention will be sequentially described in detail.

<Outer layer>
The outer layer in the laminated film of the present invention suitably comprises a material having impact resistance sufficient to protect the package and contents from physical impact applied after the production of the package, and preferably also having a barrier property. is there. Further, when the packaging body is printed, the outer layer is necessary to complement the barrier layer and the like described later, which may be damaged by the printing process.

Suitable examples of the material forming the outer layer in the present invention include polyester, polyolefin, polyamide and the like. Specific examples of these materials include:
As the polyester, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or the like;
As the polyolefin, for example, polyethylene (PE), polypropylene (PP) or the like;
As the polyamide, for example, 6-nylon, 6,6-nylon, etc.;
Each can be named.

The outer layer is preferably composed of a stretched material. By using the stretched material, the impact resistance and heat resistance of the outer layer can be further enhanced. This stretching may be uniaxial stretching or biaxial stretching.

The thickness of the outer layer is not particularly limited. In order to provide the obtained package with sufficient strength, for example, it can be 5 μm or more, and preferably 10 μm or more. On the other hand, the upper limit of the thickness of the outer layer is preferably about 20 μm from the viewpoint of avoiding the attenuation of vibration due to the application of ultrasonic waves at the time of sealing and improving the visibility of the contents when the filled package is displayed. ..

<Barrier layer>
The barrier layer which is preferably used in the laminated film of the present invention is a layer having a function of suppressing entry of gas (especially oxygen), moisture and light from the outside to protect the contents. As a material for forming such a barrier layer, for example, aluminum foil can be used, and vapor deposition having barrier properties on one side or both sides of a base film made of polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, nylon or the like. A material provided with a layer (evaporated film) can be used. The vapor deposition layer having the barrier property can be, for example, a vapor deposition film of aluminum, silica, or the like.

The thickness of the barrier layer is preferably 5 μm or more and 10 μm or less.

When the barrier layer is a vapor-deposited film, the base film thereof may also serve as the outer layer described above or the easily tearable layer described later.

<Easy tearing layer>
The easily tearable layer preferably used in the laminated film of the present invention has a function of facilitating tearing and unsealing by the hand of the consumer when opening the package. In the laminated film of the present invention, the tearability of the entire laminated film becomes good because the easily tearable layer is present adjacent to the sealant layer described later. It is considered that when the easy tear layer and the sealant layer adhere to each other, the tear performance of the easy tear layer preferably propagates to the thickest sealant layer in the laminated film to improve the tearability of the entire laminated film.

The easily tearable layer can be made of a material such as polyester, polyamide, or polyolefin. Specifically as these materials,
As the polyester, for example, polyethylene terephthalate (PET) or the like;
As the polyamide, for example, nylon or the like;
As the polyolefin, for example, polypropylene (PP) or the like;
Each can be mentioned.

It is preferable that these materials have a tear direction suitable for opening the package. For example, a uniaxially stretched film or a biaxially stretched film obtained by forcing the above materials is preferable as the easily tearable layer in the invention. Particularly preferably biaxially stretched PET, biaxially stretched nylon (for example, "Uniathlon TB1000" manufactured by Idemitsu Unitech Co., Ltd., "Emblem NCBC" manufactured by Unitika Ltd.) or a film of biaxially stretched PET (for example Unitika Ltd.). Manufactured by "Emblet PCBC").

As the easily tearable film material, various commercially available products are provided on the market, and those having appropriate properties can be selected and used from these commercially available products. For example, “Uniathlon TB1000” manufactured by Idemitsu Unitech Co., Ltd., “Emblem NCBC” manufactured by Unitika Co., Ltd., “Emblet PCBC”, and the like.

The thickness of the easily tearable layer in the present invention is
Preferably 5 μm or more, more preferably 10 μm or more; and
It is preferably 40 μm or less, and more preferably 20 μm or less.

<Sealant layer>
The sealant layer in the laminated film of the present invention is made of a material that can be melted and adhered to each other by friction caused by vibration when an ultrasonic wave is applied, and preferably has heat resistance to withstand retort treatment of contents. Specific examples of this material include low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), polypropylene (PP), and ethylene-vinyl acetate. Examples of the material include polymers, ionomer resins, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid alkyl ester copolymers, ethylene-propylene copolymers (EPM), polymethylpentene, and polybutene. be able to. Among these, LLDPE is preferable because it has a good ultrasonic sealing property, and particularly exhibits a good foreign substance sealing performance when an ultrasonic wave is applied.

The sealant layer in the present invention is a relatively thin layer made of a relatively hard material. This is ensured by the tensile elastic modulus (Young's modulus) being 200 MPa or more and 500 MPa or less and the film thickness being 10 μm or more and 50 μm or less.

The tensile elastic modulus of the sealant layer can be measured by a standard method according to JIS K7127. A particularly recommended measurement method is the measurement under the conditions adopted in the examples described later. The tensile elastic modulus of the sealant layer is preferably 225 MPa or more, and more preferably 250 MPa or more in order to suppress the attenuation of vibration due to ultrasonic waves and ensure good foreign matter sealing properties. On the other hand, the tensile elastic modulus of the sealant layer is preferably 400 MPa or less, and more preferably 350 MPa or less, from the viewpoint of melting by friction and ensuring formation of a strong seal.

The thickness of the sealant layer is preferably more than 25 μm, more preferably 30 μm or more from the viewpoint of forming a strong seal by melting. On the other hand, the thickness of the sealant layer is preferably 50 μm or less from the viewpoint of suppressing the attenuation of vibration due to ultrasonic waves as much as possible.

In addition to satisfying the above requirements, the sealant layer in the invention preferably has a heat of fusion of 110 J/g or less from the viewpoint of further improving the ultrasonic sealing property, particularly the ultrasonic foreign material sealing property. From this viewpoint, the heat of fusion of the sealant layer is more preferably 107.5 J/g or less, still more preferably 105 J/g or less. On the other hand, from the viewpoint of forming a strong seal, the heat of fusion of the sealant layer is more preferably 50 J/g or more, still more preferably 75 J/g or more.

<Optional requirements for each layer>
Each of the above layers may contain an appropriate additive as required. Examples of the additive used here include a lubricant, an antioxidant, an antistatic agent, and a colorant.

It is assumed that the laminated film of the present invention is printed with a product name, a product logo, or the like for the purpose of identifying the contents when it is used as a package or for appealing to consumers when it is displayed as a product. .. Printing is preferably performed between the outer layer and the barrier layer, or between the barrier layer and the easily tearable layer. The printing can be performed by an appropriate printing method such as gravure printing or flexographic printing.

<Laminate film>
The laminated film of the present invention has the outer layer and the sealant layer as described above. In a preferred embodiment of the present invention, each of the layers described above has an outer layer, a barrier layer, an easily tearable layer, and a sealant layer in this order. Here, the presence of the easily tearable layer and the sealant layer adjacent to each other with or without an adhesive is a requirement for improving the unsealing property (hand-cutting property) of the entire laminated film. .. Even if the same film material is used, if the stacking order is changed and, for example, the outer layer, the easily tearable layer, the barrier layer, and the sealant layer are stacked in this order, a laminated film having good tearability cannot be obtained ( See Comparative Example 6 below). The hand tearability of laminated films is related to tear strength. The preferable tear strength of the laminated film of the present invention will be described later.

Each layer in the laminated film of the present invention is preferably fixed with an appropriate adhesive. The adhesive in this case can be appropriately selected by those skilled in the art according to the method for producing the laminated film. For example, it is an adhesive for dry lamination, an adhesive for print lamination, an AC agent for extrusion lamination, or the like. The amount of the adhesive can be, for example, 0.5 g/m ² or more, and preferably 1 g/m ² or more, as an adhesive material per unit area of the film, for each interlayer. On the other hand, the amount of this adhesive can be, for example, 10 g/m ² or less, and preferably 5 g/m ² or less.

The thickness (total film thickness) of the laminated film of the present invention is preferably 120 μm or less from the viewpoint of realizing good ultrasonic sealing properties. The thickness of the laminated film is more preferably 100 μm or less, further preferably 85 μm or less, and particularly preferably 80 μm or less. On the other hand, from the viewpoint of imparting practical geometrical strength to the laminated film, the thickness of the laminated film is preferably 35 μm or more, more preferably 50 μm or more, and particularly preferably 60 μm or more.

As mentioned above, the hand tearability of a laminated film is related to the tear strength. When the tear strength of the laminated film measured according to JIS K7128-1 is 0.60 N or less, the hand tearability of the laminated film can be evaluated as good. Therefore, the tear strength of the laminated film of the present invention measured by the above criteria is preferably 0.60 N or less, more preferably 0.55 N or less, and more preferably 0.50 N or less. On the other hand, the tear strength is preferably 0.20 N or more, and more preferably 0.30 N or more, in order to avoid unintended opening except when the user intends.

The tensile elastic modulus of the laminated film of the present invention measured according to JIS K7127 is preferably 800 MPa or more. This value is more preferably 900 MPa or more, and even more preferably 1,000 MPa or more. On the other hand, the tensile elastic modulus of the laminated film is preferably 2,200 MPa or less, more preferably 2,000 MPa or less. A package produced from a film having a tensile elastic modulus in this range has excellent ultrasonic sealing properties, and is particularly preferable because it exhibits good foreign matter sealing properties by the application of ultrasonic waves.

The foreign matter seal strength, which can be evaluated as having a good foreign matter sealability, differs depending on the contents. However, as a general index, the welding strength measured using a strograph (VES10 manufactured by Toyo Seiki Seisakusho Co., Ltd.) is preferably 8.0 N/15 mm or more, and more preferably 10.0 N/15 mm or more.

The laminated film of the present invention is preferably applied as a standing pouch having excellent display properties. It is known that the self-supporting property of the package is related to the bending rigidity of the material film. It can be evaluated that the package manufactured from the film having the bending rigidity of about 25 N·mm ² or more has excellent self-standing property when used as a standing pouch. Therefore, the laminated film of the present invention, the tensile modulus and cross-sectional flexural rigidity that is calculated using the second moment of the elastic curve equation, is preferably 25 N · mm ² or more, more preferably 30 N · mm ² or more Yes, and more preferably 40 N·mm ² or more. This value is preferably 100 N·mm ² or less, more preferably 75 N·mm ² or less.

<Method for producing laminated film>
The laminated film of the present invention as described above can be produced by a known method except that the above layers are laminated in a predetermined order. For example, it can be manufactured by a dry laminating method, a wet laminating method, an extrusion laminating method, or the like, or a combination thereof. Of these, the dry lamination method is preferable.

<Bag making method>
The laminated film of the present invention is excellent in ultrasonic sealing property as described above, and particularly excellent in contaminant sealing property by application of ultrasonic waves. Therefore, the laminated film of the present invention is preferably used for bag-making filling involving an ultrasonic sealing step, and is preferably used for bag-making filling involving an ultrasonic contaminant sealing step. That is, the bag manufacturing method of the present invention preferably includes a step of ultrasonically sealing the sealant layers of the laminated film.

In bag making, first, the laminated film of the present invention is opposed or folded such that the sealant layers face each other, and two sides facing each other or one side facing the bent portion are heat-sealed to face each other. A tubular molded body having two closed sides is formed. In this molded body, the two closed sides form the bottom side and the top side of the package. At this time, by forming one of the two sides in the order of mountain fold, valley fold, and mountain fold so that the folded portion has an M-shape, a standing pouch-type package can be manufactured. it can.

Here, when the easily tearable layer of the laminated film has directionality in its tear strength, it is preferable that the direction in which the tear strength is weaker coincides with the opening direction of the tubular body. With such a configuration, it is easy to open the obtained package in the direction orthogonal to the height direction, and thus it is easy to consume the contents of the package (for example, to drink from the opening). Is obtained.

Next, the above-mentioned ordinary molded body is mounted in a commercially available bag-making machine equipped with an ultrasonic sealing device to carry out bag-making. Here, using a bag-making filling machine that performs bag-making while filling the contents as a bag-making machine, performing the bag-making filling in a mode in which the ultrasonic seal is a contaminant seal is an advantage of the laminated film of the present invention. Is preferable in that it can be maximized. The contents provided for bag-making filling can be, for example, any liquid such as foods, seasonings, pharmaceuticals, supplements, viscous bodies, or powders.

The package obtained by using the laminated film of the present invention as described above, the contents are not leaked due to the excellent sealing property, and it is easy for the consumer to easily and comfortably because it is excellent in hand-cutting property at opening. When the packaging is a standing pouch, it can be opened, and since it has excellent self-supporting property, a display appealing to consumers is possible.

The details of the resin film used as the material forming each layer in the following Examples and Comparative Examples are as shown in Table 1 below.

<Evaluation of foreign matter sealability>
[Examples 1 to 3 and Comparative Examples 1 to 4]
In Examples 1 to 3 and Comparative Examples 1 to 3, the contaminant sealability was evaluated when condensed milk, which was difficult to seal contaminants, was used as the content.

(1) Manufacture of Laminated Film As an outer layer, PET having a mark for sample identification written on one surface was used. AL was used as the barrier layer, tear Ny was used as the easy tear layer, and LLDPE of the type shown in Table 2 was used as the sealant layer. A laminated film was manufactured by dry laminating these layers in the order described above with 3 g/m ² of a dry laminating adhesive (manufactured by Rock Paint Co., Ltd., product name “RU-50”) interposed therebetween. .. The outer layer was laminated with the printing surface facing the barrier layer side. The laminated films in these experimental examples are the same in the constitution of the outer layer, the barrier layer, and the easily tearable layer except that the kind of the sealant layer is different.

(2) Implementation of bag-making filling Using each of the laminated films obtained above, bag-making filling was carried out. The procedure for bag filling will be described with reference to FIG.

Two laminated films 5 were prepared, stacked so that the sealant layer was on the inside, and set in a bag-making filling machine equipped with a longitudinal vibration ultrasonic sealing device (FIG. 2(a)). These films are vertically long, and the width direction of the film (the direction orthogonal to the flow direction) is the height direction of the filled package.

Both of the two widthwise ends 12 of these two films 5 (top and bottom of the obtained packed package) were heat-sealed to form a tubular body (FIG. 2B). Further, the bottom portion 13-1 (one side end portion of the obtained packed package) of this tubular film is ultrasonically sealed in a direction orthogonal to the flow direction to form a bag, and then the nozzle 10 is filled with the contents 11 Started to be filled. Ultrasonic sealing was performed at an output of 300 J in a width of 65 mm for 0.3 seconds, and condensed milk was used as the content 11. Condensed milk is known in the art as the most difficult content to seal with contaminants.

When the filling of the content 11 exceeds one portion, the portion 13-2 in FIG. 2(d) is ultrasonically sealed (contamination) under the same conditions as above, and the content 11 is placed in the film. Sealed.

Next, by cutting the center of the 13-2 ultrasonically sealed portion, a vertically long filled package 20 having a length of 110 mm, a width of 55 mm, and a bottom width of 40 mm filled with 30 g of condensed milk as the content 11 was manufactured.

(3) Evaluation of foreign matter sealability (when the content is condensed milk)
The ultrasonic sealing portion (contamination part) of the obtained packed package was subjected to a T-type peeling test in accordance with JIS K6854-3, and the contamination strength (condensed milk) was examined. The results are shown in Table 2.

The heat of fusion of the sealant layer is a parameter indicating the ease of fusion by heat. In the case of heat sealing, it is known that the lower the heat of fusion, the higher the sealing performance.

However, in the case of foreign matter sealing by ultrasonic waves, even if the heat of fusion is low, when a sealant layer having a low tensile modulus is used, the sealing property as a bag body containing a filling material may be insufficient. It was understood (Comparative Example 3).

In the case of ultrasonic contaminant sealing, it is important to use a sealant material having a high tensile elastic modulus as a comparative example thin layer even if the heat of fusion is high to some extent in order to obtain good sealing properties. It was found (Examples 1 to 3).

<Evaluation of tearability/sealing of foreign substances (water content)/self-supporting property using a laminated film and filling bag>
[Examples 4 to 10]
In Examples 4 to 10, filling bag making was performed using water as the content, and tearability, contaminant sealing property (water), and independence of the obtained filled package were evaluated.

(1) Production of Laminated Film As the laminated film in Example 4, the laminated film obtained in Example 1 was used.
In Examples 5 to 10, laminated films were produced in the same manner as in Example 1 except that the layer constitution was as shown in Table 3.

(2) Evaluation of Laminated Film i) Measurement of Tear Strength The tear strength of the laminated film was measured by the trouser method in the environment of 23° C. and relative humidity of 50% according to JIS K7128-1. The test speed was 200 mm/min, and the tearing direction was the MD direction of the film.

ii) Measurement of tensile elastic modulus and evaluation of bending rigidity The tensile elastic modulus (Young's modulus) of the laminated film was measured in accordance with JIS K7127 under an environment of 23° C. and relative humidity of 50%, and a tensile speed of 100 mm. Per minute.

The flexural rigidity of the laminated film was calculated using the elastic curve equation from the tensile elastic modulus measured above and the second moment of area calculated from the total film thickness of the laminated film.

(3) Implementation of bag-making filling Each of the laminated films obtained above was folded in the order of mountain fold, valley fold, and mountain fold so that the sealant layer was on the inner side, and the folded portion was M-shaped. .. This M-shaped bent portion serves as the bottom portion of the filling package, and the opposite end portion serves as the top portion.

This folded film is set in a bag-making and filling machine equipped with a longitudinal vibration ultrasonic sealing device, and when it is formed into a tubular body, a heat seal is applied to the side end portion (obtained) which is opposite to the folded portion. A vertically long filled package (standing bag) having a length of 110 mm, a width of 55 mm, and a bottom width of 40 mm is manufactured in the same manner as in Example 1 except that water is used only as the content of the top of the filled package. did.

(4) Evaluation of standing bag i) Evaluation of foreign matter sealing property The ultrasonic sealing portion (foreign matter sealing portion) of the filled package obtained above was subjected to a T-type peeling test in accordance with JIS 6854-3. The foreign matter seal strength (water) was examined. The results are shown in Table 3.

ii) Evaluation of self-supporting property A film whose bending rigidity is calculated from the tensile modulus of elasticity and the second moment of area of the laminated film constituting the obtained standing bag using an elastic curve equation, and the calculated value is approximately 25 N·mm ² or more It was evaluated that the packaging produced from the product was excellent in self-standing property when used as a standing pouch.

The evaluation results are shown in Table 3.
<Example 11>
A laminated film was produced in the same manner as in Example 4 except that the order of laminating the barrier layer and the easily tearable layer was changed, and bag-filling and filling were performed using the laminated film for evaluation. The results are shown in Table 3 together with the total thickness of the obtained laminated film.

Example 8 using a commercially available coating film as the outer layer and the barrier layer was inferior in self-supporting property. It is considered that this is due to the low bending rigidity of the laminated film. In Examples 9 and 10 in which the thickness of the sealant layer was thicker than that in Example 8, the self-supporting property of the filled package was secured, but the tear strength was increased and the hand tearability was poor. Do you get it.

On the other hand, it was confirmed that the laminated film of Example 4, which is a typical embodiment of the present invention, had a low tear strength of 0.34 N and showed good hand tearability. However, it was found that the laminated film of Example 11 in which the laminating order of each layer was changed while using the same type of film showed a high tear strength value and poor hand tearability.

In the case of Example 4 in which the easily tearable layer is arranged adjacent to the sealant layer which is the thickest layer in the laminated film, this phenomenon is that the easily tearable property of the easily tearable layer propagates to the sealant layer. As a result, it is considered that the tearability of the entire laminated film was improved.

In the filled packages of Examples 4 to 11, the sealant layer used satisfies the requirements specified in the present invention, and therefore, condensed milk, which is difficult to seal impurities, is used as the content instead of water. However, it is presumed that it exhibits excellent foreign matter sealing property.

1 Outer Layer 2 Sealant Layer 3 Barrier Layer 4 Easy Tear Layer 5 Laminated Film 10 Nozzle 11 Contents 12 Heat Sealing Part 13 Ultrasonic Sealing Part 13-1 Ultrasonic Sealing Part (1)
13-2 Ultrasonic Sealing Part (2)

Claims (10)

Having an outer layer and a sealant layer,
The sealant layer, Ri tensile modulus layer der film thickness 10μm or 50μm or less made of 500MPa or less of the thermoplastic resin or higher 200 MPa,
It is used for bag making and filling while filling the contents, and
The bag filling is accompanied by an ultrasonic foreign material sealing step,
Laminated film. Further having a barrier layer and an easily tearable layer between the outer layer and the sealant layer,
The easily tearable layer is a layer formed of a uniaxially stretched film or a biaxially stretched film of a resin selected from polyester, polyamide, and polyolefin, and
The sealant layer and the easy tear layer are adjacent to each other with or without an adhesive,
The laminated film according to claim 1. The total film thickness is 50 μm or more and 100 μm or less, and the tear strength is less than 0.6 N,
The laminated film according to claim 2. The barrier layer is a layer composed of aluminum foil, or
The outer layer and the barrier layer,
On one or both sides of the base film made of polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, or nylon,
A vapor-deposited layer of aluminum or silica is provided
It is a vapor deposition film,
The laminated film according to claim 2 or 3. The sealant layer is a layer made of LLDPE,
The laminated film according to any one of claims 1 to 4 . The laminated film according to claim 1, wherein the content is a liquid, a viscous material, or a powder. The laminated film according to claim 6, wherein the content is a food, a seasoning, a drug, or a supplement. A bag-making method comprising a step of ultrasonically sealing the sealant layers of the laminated film according to any one of claims 1 to 8 ,
The bag-making method is a bag-making filling method for performing bag-making while filling the contents, and
The ultrasonic sealing step is an ultrasonic foreign material sealing step,
Bag making method. The bag manufacturing method according to claim 8, wherein the content is a liquid, a viscous material, or a powder . The bag manufacturing method according to claim 9, wherein the content is a food, a seasoning, a drug, or a supplement.

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