JP6492559B2 - Pouch manufacturing method - Google Patents

Description

  The present invention relates to a pouch for packaging a liquid, powder, granule, solid, or the like, which can be easily opened by tearing one end of the pouch.

  Conventionally, a stiffener with a peripheral edge of a laminated packaging material based on a plastic film filled with a liquid such as cosmetics or detergents, powders such as spices, granulated food toiletries, etc., and the innermost layer being a sealant layer is sealed. Dig pouches and other pouches are known. In order to open the pouch easily by tearing the hand, for example, it is sealed in four directions, and a V-shaped notch is cut in the planned opening part on the upper side of the left side seal part in order to tear the upper side. There is a pouch, and this V-shaped notch is the starting point, which is torn by hand and opened.

  However, in the case of only the V-shaped notch cut into the opening-scheduled part, unless the laminated packaging material uses a highly stretched film that is costly, the opening-scheduled part starts from this V-shaped notch. When tearing in the direction by hand, it will not be torn parallel (straight), but it will be torn diagonally and the contents will spill, the tearing strength will be excessive, it will be difficult to tear, or the plastic film that tears in the middle will break There was a problem such as.

With respect to such a problem, in Patent Document 1,
In the packaging bag in which the sealant layer surface of the packaging material film, the innermost layer of which is a sealant layer, faces each other, the peripheral edge thereof is sealed, and the peripheral sealing portion has a planned opening portion by tearing at one side edge. A plurality of continuous V-shaped half-cut grooves whose apexes are directed in the planned opening direction are engraved in parallel at the site, and continuous linear half-cut grooves so as to pass through the apexes of the V-shaped half-cut grooves Further, one or more linear half-cut grooves continuous from the apex of the V-shaped half-cut groove to the upper side and the lower side are cut so as to intersect or contact the V-shaped half-cut groove. We propose an easy-open packaging bag characterized by

FIG. 2B is a cross-sectional view of a tearing tear portion in a conventional pouch that has been half-cut, and the half-cut 6 is in the adhesive layer 11.
A thermoplastic resin layer 12 is provided on the front side of the base film 11, and a sealant layer 13 is provided on the inner side.
In this figure, a barrier layer 14 assuming a metal foil is further provided between the adhesive layer 11 and the sealant layer 13 which is the innermost layer.
Half-cutting is performed manually by leaving a blade in the outermost layer, leaving half of the main base material layer of the laminated film 10 or the innermost sealant layer 13 in a process such as outline cutting. In this case, here, it is assumed that the cutting is performed in combination with a half cut in which a blade is linearly inserted from one end to the other end, or V-shaped vertices are arranged in a straight line. There are also half-cuts that appear in broken lines like perforations.
However, the outer layer 12 is often made of a resin that is strong and difficult to stretch, such as a biaxially stretched polyethylene terephthalate film. Therefore, it cannot be easily torn by hand unless a blade is put in advance in more than half of the thickness of the outer layer film, preferably in more than two-thirds.
Blades used for half-cutting were flat-cutting blades such as big blades, engraving blades, corrosion blades, and rotary blades. In these, the depth at which the blade enters is easily changed due to a subtle difference in pressure between the blades. In such a situation, the half-cut was inserted, so the depth of the blade could not be accurately controlled, the blade entered deeply and reached the sealant layer 13, the barrier layer was destroyed, and the barrier However, there has been a problem that the drop of impact strength and the drop impact strength are reduced and the bag is broken during transportation. In addition, the half-cut blade is too shallow, the base material is not cut sufficiently, and it may not be able to be torn by hand.

  In particular, processing by crossing the half cut as in Patent Document 1 causes a significant decrease in physical properties partially, and the occurrence rate of defects such as leakage rises from the partially opened planned portion, There was a problem that functions such as barrier properties of the packaging bag could not be maintained.

Japanese Patent No. 4760030

  Therefore, it is an object of the present invention to obtain a pouch that can secure a barrier property and can be easily opened without damaging the layer of the packaging bag unlike a half cut.

The invention according to claim 1 of the present invention, at least in the pouch manufacturing method of a laminated film having a sealant layer made of a thermoplastic resin layer and the innermost layer of the polypropylene film made of a polyethylene terephthalate film of the outermost layer, the pouch A band-shaped opening tear portion is provided in the inner region of the peripheral seal portion when the bag is made , and the opening tear portion is formed by thermally compressing the laminated film at a temperature equal to or higher than the glass transition point of the thermoplastic resin layer. The pouch manufacturing method is characterized in that the tear strength of the tear portion is 60% or less of the tear strength of the non-compressed portion .

The invention according to claim 2 of the present invention is the method for producing a pouch according to claim 1, wherein the laminated film includes a barrier layer.

The invention according to claim 3 of the present invention is characterized in that the pouch according to claim 1 or 2 is further subjected to thermal compression in the vicinity of the center of the heat-compressed opening tearing portion and further with a width of 5 mm or less . It is a manufacturing method .

Since the packaging body of the present invention does not damage the layer of the packaging bag like half-cut, not only can the barrier property be secured, but also a pouch that can be easily opened can be stably processed, There is a merit that it is difficult for defects to occur.
Moreover, this easy-opening process may be performed on a single film before being laminated, or may be processed before being laminated to form a bag.
For this reason, since the process is easy to assemble and can be processed by adding only one or two heat compression processes, the conventional production line can be easily modified and used.

It is an example of the pouch of this invention, and is an external appearance perspective view. It is the longitudinal cross-sectional view of the laminated film which shows the cross section of the tearing tear part in the pouch of this invention, and the conventional pouch which gave the half cut. It is the figure which showed the example of the process of the pouch of this invention. It is sectional drawing which showed typically the change of resin by heat compression.

Hereinafter, the pouch of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an example of a pouch according to the present invention, and is an external perspective view in which an opening tearing portion 5 is applied to a standing pouch by heat compression.
The pouch 1 of the present invention is not particularly noticeably different from the conventional pouch provided with a half tear-cut open tearing portion.
As shown in FIG. 1, the end of the opening tearing portion 5 may be provided with a notch 4, or the opening tearing position may be indicated by printing.
Since there is no difference in appearance from other non-heat-compressed parts, it is desirable to provide an indication that indicates to the consumer some tearing position.

FIG. 2 is a longitudinal sectional view of a laminated film showing a cross section in the vicinity of an opening tearing portion 5, FIG. 2-1 is a pouch of the present invention having an opening tearing portion thermally compressed, and FIG. 2-2 is a conventional half cut It is a pouch.
FIG. 2-1 is a pouch according to the present invention, which has an unsealed tear portion that is heat-compressed in a band shape without being half-cut. A thermoplastic resin layer 12 is provided on the front side of the adhesive layer 11, and a sealant layer 13 is provided on the inner side.
In this figure, a barrier layer 14 of metal foil is further provided between the adhesive layer 11 and the innermost sealant layer 13.
In this figure, as a first stage, a first thermal compression is performed on a 12 mm wide band to provide a first fracture band 51, and a 5 mm wide band is formed at the center of the second heat of the second stage. The second fracture band 52 is provided by compression.
These layers are not subject to breakage due to thermal compression, but are applied to a temperature above the glass transition point of the thermoplastic resin layer, and change the orientation of the aligned resin molecules by heat and pressure. It ’s just that.

The heat compression method was performed by heating and compression with a heat sealer.
This heat sealer may be an impulse sealer or a normal hot plate heat sealer.
In the case of an impulse sealer, pressing, heating, and cooling are sequentially performed in a pressed state, but in the case of a hot plate heat sealer, a silicon film or the like is interposed or a non-adhesive resin is impregnated at the tip. It is preferable to use such a heat head.

FIG. 4 schematically shows the state of the resin in the film forming portion 50 that is not thermally compressed, the first fractured band 51 portion that has undergone the first thermal compression, and the second fractured band 52 that has undergone the second thermal compression. .
FIG. 4A shows the film-forming part 50, the first breaking band 51, and the second breaking band 52 in the vicinity of the opening tearing part 5 of the thermoplastic resin layer 12 shown in FIG. 2.
The film-forming part 50 that is not thermally compressed in FIG. 4-2 is obtained by melting the resin, extruding it from the die, and cooling it. However, it is necessary to apply tension during film formation, and it may not be in a completely stretched state. However, it is stretched in the film forming process to some extent, and the molecules are aligned in the stretched direction.
In the first fracture band 51 in which the film-forming portion 50 of FIG. 4-3 that is not thermally compressed is first thermally compressed, since it is a thermoplastic resin, the bond between molecules is released by heating, and it is a crystallized resin. Therefore, each molecule shrinks and each folds. In particular, since it is compressed while heating, the molecules are forced to move and the release of the bonds between the molecules is promoted.
In the second fractured band 52 that has been subjected to the second thermal compression in FIG. 4-4, since it is heated and compressed again, the bonds between the molecules are further released, and the molecules are further folded and become spherulitic.
Eventually, since the bonds between the molecules constituting the layer are released, the opening tearing portion 5 by thermal compression changes so that it can be easily torn.

The thermoplastic resin layer 12 on the front side and the sealant layer 13 on the inner side are easy to tear as described above. By the way, when the outer thermoplastic resin layer is made of a resin having a high crystallization rate, such as polyethylene terephthalate resin or polypropylene resin, compared with polyethylene, the tearability changes much more greatly.
That is, a layer made of a resin having a high crystallization rate, such as polyethylene terephthalate resin or polypropylene resin, is stretched at a high stretch ratio using a dedicated machine at a temperature higher than the glass transition point and lower than the melting point at the time of film formation. A film is formed. Therefore, the bonds between the molecules are released by thermal compression, and the stretched molecules are folded and changed so as to be easily torn, and the change in tearability before and after thermal compression becomes larger. Occasionally with such resins, crystallization proceeds, transparency decreases and whitens.

FIG. 3 is a view showing an example of processing of the pouch according to the present invention.
As shown in FIG. 3A, first, the laminated film constituting the pouch is subjected to thermal compression in a band shape in a sheet state, and an opening tearing portion 5 is provided. An arrow print 53 and a cut portion print 54 are made so that the position of the opening tearing portion 5 can be clearly seen.
An impulse sealer is convenient for heat compression. In this case, the amount of power flowing through the sealer can be controlled by the voltage, current, and time passed through the strip-shaped thin nichrome plate, and the pressure for compression can be easily adjusted. Of course, the width of the thin strip-shaped nichrome plate becomes the width of the opening tearing portion 5.
The width of the first fracture band 51 subjected to the first thermal compression is preferably 10 mm or more and 100 mm or less. If it is less than 10 millimeters, the front and back sides may be displaced from the heat-compressed portion due to the deviation of the opening position. On the other hand, if it is 100 millimeters or more, large distortion is caused in the film, and stable production cannot be performed.
The heat compression temperature needs to be higher than the temperature at which the sealant can be sealed. For example, about 110 ° C. is preferable when the sealant is low-density polyethylene, and about 140 ° C. is preferable when the sealant is polypropylene.
In addition, the width of the second fracture band 52 to be second thermally compressed is 5 millimeters or less. This is because in the case of 5 mm or more, it is difficult to tear along a line. Of course, if it is not necessary to tear it linearly, the second breaking band 52 may not be provided, and the width of the second breaking band 52 may be 5 millimeters or more.

Use a film with an opening tear 5 made by the above heat compression, and align the left and right ends of the film so that the opening tear 5 is in the same position as the front and back as shown in FIG. Then, the back seal 21 is sealed. Of course, a side seal may be used instead of the back seal.
Thereafter, the bottom seal 22 is used to change the shape from a cylindrical shape to a bag shape, the contents are injected from the open upper portion, and the upper side of the tearing tearing portion 5 is fused and sealed.

  Specific examples of the present invention will be described below.

<Example 1>
As an outer layer, polyethylene terephthalate biaxially stretched film 12 micrometer.
As a sealant layer, linear low density polyethylene 50 micrometer.
They were pasted together by a dry lamination machine through a polyurethane-based adhesive to form a laminated film and slit.
In the state of the laminated film with the slits applied, a heat tearer applied a heat compression of a temperature of 130 ° C., a pressure of 0.2 MPa, and a time of 1 second to provide an opening tearing portion.
Side sealing and bottom sealing were performed, and a sample 5 cm square cardboard was put in, and the upper 5 mm ahead of the opening tear was sealed up.

<Example 2>
A laminated film having the same configuration as that of Example 1 was prepared, and the first heat compression was performed at a temperature of 130 ° C., a pressure of 0.2 MPa, and a time of 1 second by a heat sealer with a width of 40 mm, and then in the center of the width, A second heat compression with a width of 5 millimeters, a temperature of 130 ° C., a pressure of 0.2 MPa, and a time of 1 second was applied by a heat sealer to provide an opening tear.
Side sealing and bottom sealing were performed, and a sample 5 cm square cardboard was put in, and the upper 5 mm ahead of the opening tear was sealed up.

<Example 3>
A laminated film having the same configuration as that of Example 1 was prepared, and the first heat compression was performed at a temperature of 130 ° C., a pressure of 0.2 MPa, and a time of 1 second by a heat sealer with a width of 40 mm, and then in the center of the width, A second heat compression with a width of 8 mm, a temperature of 130 ° C., a pressure of 0.2 MPa, and a time of 1 second was applied by a heat sealer to provide an opening tear.
Side sealing and bottom sealing were performed, and a sample 5 cm square cardboard was put in, and the upper 5 mm ahead of the opening tear was sealed up.

<Example 4>
An unstretched polypropylene 70 micrometer was used as the sealant layer. (The vertical direction of the pouch is the film flow direction.)
Otherwise, a laminated film was made in the same manner as in Example 1. The film was 40 millimeters wide and was subjected to heat compression at a temperature of 130 ° C., a pressure of 0.2 MPa, and a time of 1 second with a heat sealer to provide an opening tear.
Side sealing and bottom sealing were performed, and a sample 5 cm square cardboard was put in, and the upper 5 mm ahead of the opening tear was sealed up.

<Comparative Example 1>
A laminated film having the same structure as that of Example 1 was prepared, and side sealing and bottom sealing were performed in a state where the film was not thermally compressed, and a sample 5 cm square cardboard was put, and the upper 5 mm tip of the opening tearing portion was top sealed.

<Comparative example 2>
An unstretched polypropylene 70 micrometer was used as the sealant layer. (The vertical direction of the pouch is the film flow direction.)
Others made a laminated film that was the same as in Example 1, side sealed and bottom sealed without heat compression, put a sample of 5 cm square cardboard, and sealed the upper 5 mm ahead of the opening tear. .

<Evaluation test contents>
About the Example and the comparative example, it tested by the following method and compared and evaluated.
<Easy cutting>
Three pouches were given to 10 general housewives, 30 pouches in total, and tearing was performed by hand. As a result, 28 or more pouches that could be easily torn were rated as ◯, and less than that as x.
<Tear strength>
A & D Co., Ltd. tensile and compression testing machine, Tensilon Universal Material Testing Machine (registered trademark) RTG-1250, sandwiching the top and bottom of the tearing part, tearing at a speed of 300mm / min, tear strength Was measured. Three pouches were measured and the average was determined.
<Tearing linearity>
The case where the tearing part torn with the tearing strength was placed between two straight lines with a width of 3 millimeters parallel to the upper seal was marked with ◯.

  <Evaluation results>

In Example 1, the easy-cut property was ◯, but the tear linearity was x, and the tear strength was 1.2 N (Newton).
In Example 2, the easy-cut property and tear linearity were both good, and the tear strength was 1.1 N (Newton).
In Example 3, the easy-cut property was ◯, but the tear linearity was x, and the tear strength was 1.1 N (Newton).
In Example 4, the easy-cut property was ◯, but the tear linearity was x, and the tear strength was 2.9 N (Newton).
In Comparative Example 1, both easy-cut property and tear linearity were x, and the tear strength was 6.8 N (Newton).
In Comparative Example 2, easy cutability and tear linearity were both x, and the tear strength was 5.1 N (Newton).

  As described above, the tearability increased in the heat-compressed example. In particular, as in Example 1, Example 2, and Example 3, the pouch using linear polyethylene as the sealant layer was reduced to a tear strength of 20 percent or less compared to Comparative Example 1 that was not thermally compressed, High tearability was secured.

  Moreover, from the evaluation results of Comparative Example 2 in which the thermal compression is not performed and Example 4 in which the thermal compression is performed among the evaluation results, the tear strength of the thermal compression portion is 60% or less of the tear strength of the non-thermal compression portion. By doing so, it can be said that easy-cut property is expressed.

  Furthermore, the results of Example 2 and Example 3 indicate that the straightness of tearing is improved when the width of the second thermal compression is 5 mm, but is too large at 8 mm.

  Furthermore, it can be seen that polypropylene can be used not only as a sealant but also to be tearable by thermal compression if it is not stretched.

  The film used for the sealant layer used in the present invention is a high pressure method low density polyethylene, linear low density polyethylene, medium density polyethylene, polypropylene, ethylene / propylene copolymer resin, ethylene / vinyl acetate copolymer, ethylene / meta. Olefin resins such as acrylic acid copolymer, ethylene / acrylic acid copolymer, and ethylene / methyl acrylate can be used.

  Moreover, although the film used for the outer layer used for this invention is a thermoplastic resin, a biaxially stretched polypropylene film other than the biaxially stretched polyethylene terephthalate film shown in the Example can be used.

  Further, as the barrier layer, barrier properties are obtained by using a metal foil such as aluminum or a film provided with a metal film such as aluminum or a metal oxide film such as silicon oxide by vapor deposition on the inner surface side of the outer layer. I can do it.

The pouch of the present invention is as described above, and does not hurt the pouch layer like a half cut. Therefore, it is possible not only to obtain a pouch that can secure barrier properties and that can be easily opened, but is stable. Since it can be processed, defects are unlikely to occur.
Moreover, this easy-opening process may be performed on a single film before lamination, or may be processed before laminating and making a bag, so that the process is easy to assemble and the heat compression process is 1 Since the processing can be performed by adding only two steps or processes, the merit of the present invention is great such that the production line can be easily modified and used.

1 ... Pouch 10 ... Laminated film 11 ... Adhesive layer 12 ... Thermoplastic resin layer 13 ... ... sealant layer 14 ... barrier layer 21 ... back seal 22 ... bottom seal 23 ... top Seal 4 ··································································································
51 ... First fracture band 52 ... Second fracture band 53 ... Arrow print 54 ... Cut section Print 7 ... Molecule (There is a connection between resin molecules)
71 ・ ・ ・ ・ ・ ・ ・ ・ Molecules (Relation between resin molecules is released)
72 ・ ・ ・ ・ ・ ・ ・ ・ Molecules (The bond between resin molecules is released more)

Claims (3)

In the manufacturing method of a pouch comprising a laminated film having at least a thermoplastic resin layer comprising a polyethylene terephthalate film as an outermost layer and a sealant layer comprising a polypropylene film as an innermost layer, the inner region of the peripheral seal portion when the pouch is made into a bag A band-shaped opening tear portion , and the opening tear portion is formed by thermally compressing the laminated film at a temperature equal to or higher than the glass transition point of the thermoplastic resin layer , and the tear strength of the opening tear portion is that of the uncompressed portion. A method for producing a pouch characterized by being 60% or less of the tear strength . The method for producing a pouch according to claim 1, wherein the laminated film includes a barrier layer. 3. The method of manufacturing a pouch according to claim 1 or 2 , wherein the heat compression is further performed in the vicinity of the center of the heat-opened tearing portion at a width of 5 mm or less.