Spouted packaging bag, and manufacturing method of spouted packaging bag

Abstract

To provide a spouted packaging bag that can improve drop resistance even when using a laminated film composed of a mono-material.SOLUTION: A spouted packaging bag 1 includes: a storage section formed of a laminated film 16 consisting of a base material 17 and a sealant layer 18 made of the same material; and a discharge tube and a base 22 provided at one end of the discharge tube, along with a spout 20 attached to the edge of the storage section. At the upper end 11 of the storage section, the sealant layer 18 is welded to the base 22 of the spout 20, and the sealant layers 18 are welded to each other beside the base 22. A thickness D1 of the laminated film 16 at the end 22c, which is on the opposite side of the discharge tube within a welded area R1 where the sealant layer 18 is welded to the base 22, is 70% or over compared to a thickness D2 of an unwelded portion 16b of the laminated film 16.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a spouted packaging bag and a method for manufacturing a spouted packaging bag. [Background technology]

[0002] A spout-equipped packaging bag is known that can hold a predetermined content (e.g., liquid detergent or shampoo) and dispense the content as needed. The packaging material that constitutes this packaging bag is a multi-material laminate film that includes a sealant layer made of polyolefin or the like and a base material made of a material (e.g., polyester) with a higher melting point than the sealant layer. From the perspective of environmental considerations, efforts have been made in recent years to convert packaging materials to mono-materials, and the use of laminate films whose main constituent material is polypropylene or the like as packaging materials instead of multi-material laminate films has been considered (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-157517 Summary of the Invention [Problem to be solved by the invention]

[0004] When producing a spout-equipped packaging bag using a mono-material laminate film, the melting point of the sealant layer is the same as that of the base material, so compared to a multi-material structure, it is more difficult to adjust the melting of the sealant layer when welding it to the spout, and the laminate film may become thin in parts.For this reason, when a drop bag test is conducted with the contents sealed in a spout-equipped packaging bag, in the case of a mono-material structure, the laminate film may tear near the spout.

[0005] An object of the present invention is to provide a spouted packaging bag that can improve drop resistance even when a mono-material laminated film is used, and a method for manufacturing the spouted packaging bag. [Means for solving the problem]

[0006] [1] One aspect of the present invention relates to a spout-equipped packaging bag. This spout-equipped packaging bag includes a container formed from a laminate film including a base material and a sealant layer made of the same material, and a spout attached to the edge of the container, which has a pouring tube and a base provided on one end of the pouring tube. At the edge of the container, the sealant layer is welded to the base of the spout, and the sealant layers are welded to each other next to the base. In this spout-equipped packaging bag, the thickness of the laminate film at the end opposite the pouring tube in the welded area where the sealant layer is welded to the base is 70% or more of the thickness of the unwelded portion of the laminate film.

[0007] According to the inventors' investigations, when a spout-equipped packaging bag is produced by attaching a mono-material laminate film to a spout using a normal welding method, as shown in Figures 7(a) to (c), a resin reservoir 122b of molten resin is formed near the lower end 122c of the base 122 of the spout 120, and this resin reservoir 122b reduces the thickness of the laminate film 116 (layer including the sealant layer) above it. On the other hand, it has also been found that when a predetermined content is sealed in the spout-equipped packaging bag, internal pressure is likely to be applied near the lower end 122c of the base 122. For this reason, if a spout-equipped packaging bag containing a content is dropped, and the thickness of the laminate film near the lower end of the spout base is thin, the bag may tear near this lower end. Therefore, the present inventors have conducted further research to prevent such bag tearing and have come up with a configuration in which, in a spouted packaging bag having a mono-material structure, the thickness of the laminate film at the end (lower end) opposite the pouring tube in the welded region where the sealant layer is welded to the base is 70% or more of the thickness of the unwelded portion of the laminate film.With this configuration, it is possible to improve the drop resistance of the spouted packaging bag even when a mono-material laminate film is used.

[0008] [2] In the spout-equipped packaging bag of [1] above, the thickness of the laminate film at the end of the welded region may be 100% or more of the thickness of the unwelded portion of the laminate film. In this case, even when a mono-material laminate film is used, the drop resistance of the spout-equipped packaging bag can be further improved.

[0009] [3] In the spout-equipped packaging bag of [1] or [2] above, it is preferable that the spout base does not have a resin reservoir where the spout melts near the end of the welded region. In this case, the laminate film is not thinned due to the influence of the resin reservoir, and the laminate film at the end of the spout base can be more reliably maintained at a sufficient thickness. In addition, it is possible to prevent the resin reservoir, which is a part that can cause the spout-equipped packaging bag to break when dropped, from being present at the end. From the above, it is possible to reliably improve the drop resistance of the spout-equipped packaging bag even when a laminate film with a mono-material configuration is used.

[0010] [4] In the spout-equipped packaging bag of any one of [1] to [3] above, the laminate film may include a pair of laminate films, and the spout may be attached to one end of the pair of laminate films. The containing section may have a bottom film including a base material and a sealant layer made of the same material as the pair of laminate films and having a mountain fold, and the bottom film may be welded to the other end of the pair of laminate films to form a self-standing packaging bag. In this case, a mono-material standing pouch can be provided.

[0011] [5] In the spouted packaging bag of any one of [1] to [4] above, the same material constituting the base material of the laminated film and the sealant layer is preferably a polyethylene resin or a polypropylene resin, thereby improving the recyclability of the spouted packaging bag.

[0012] [6] In the spouted packaging bag of any one of [1] to [5] above, it is preferable that the same material constituting the base material of the laminated film and the sealant layer is a polyethylene resin, and that the content of the polyethylene resin in the entire laminated film is 90 mass % or more. This can improve the recyclability of the spouted packaging bag.

[0013] [7] Another aspect of the present invention relates to a method for manufacturing a spout-equipped packaging bag. This method for manufacturing a spout-equipped packaging bag includes the steps of: preparing a laminate film including a base material and a sealant layer made of the same material; preparing a spout having a pouring tube and a base to be provided on one end of the pouring tube; and attaching the laminate film to the spout by welding the sealant layer to the base of the spout and welding the sealant layers to each other next to the base. In this manufacturing method, in the attaching step, the laminate film is welded so that the thickness of the laminate film at the end of the welded region where the sealant layer is welded to the base, opposite the pouring tube, is 70% or more of the thickness of the unwelded portion of the laminate film.

[0014] In this method for manufacturing a spout-equipped packaging bag, in the attachment step, the laminate film is welded so that the thickness of the laminate film at the end opposite the pouring tube in the welded region where the sealant layer is welded to the base is 70% or more of the thickness of the unwelded portion of the laminate film. By ensuring a sufficient thickness of the laminate film at the end (lower end) of the spout base, this manufacturing method can produce a spout-equipped packaging bag with improved drop resistance, even when using a mono-material laminate film. Furthermore, the inventors have found through their studies that when attempting to manufacture a spout-equipped packaging bag using a mono-material laminate film in a conventional configuration, the conditions (the range of welding (sealing) temperatures) for manufacturing a spout-equipped packaging bag with high drop resistance are extremely narrow. For this reason, manufacturing methods using conventional configurations result in reduced productivity. However, this manufacturing method allows for a wider range of manufacturing conditions for achieving a predetermined level of drop resistance in the packaging bag, thereby improving productivity and increasing the yield rate.

[0015] [8] In the method for manufacturing a spout-equipped packaging bag described in [7] above, the step of attaching the laminate film preferably includes the steps of: placing the laminate film on the spout base; and then pressing a heating element against the base at a position shifted from the end of the base opposite the pouring tube toward the pouring tube to weld the laminate film to form a first welded body, in which a resin reservoir formed near the tip of the heating element is formed in the first welded body by melting a portion of the base; and pressing the heating element against a region of the first welded body including at least the resin reservoir to further weld the laminate film to form a second welded body. This manufacturing method can easily make the thickness of the laminate film at the end of the welded region where the sealant layer is welded to the base 70% or more of the thickness of the unwelded portion of the laminate film. Therefore, this manufacturing method can easily produce a spout-equipped packaging bag with improved drop resistance, even when using a laminate film with a mono-material configuration. [Effects of the Invention]

[0016] According to the present invention, even when a laminated film having a mono-material structure is used, the drop resistance of a spout-equipped packaging bag can be improved. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a front view showing a spout-equipped packaging bag according to one embodiment. [Figure 2] FIG. 2(a) is a cross-sectional view of a laminated film that constitutes the spout-equipped packaging bag shown in FIG. 1, and FIG. 2(b) is a cross-sectional view showing a modified example of the laminated film. [Figure 3] FIG. 3(a) is a front view showing a spout used in the spout-equipped packaging bag shown in FIG. 1, and FIG. 3(b) is a view of the spout as seen from below (the base side). [Figure 4] FIG. 4(a) is an enlarged front view showing the vicinity of the welded portion of the spout in the spout-equipped packaging bag shown in FIG. 1, and FIG. 4(b) is a cross-sectional view of the vicinity of the welded portion of the spout. [Figure 5]FIG. 5 is an enlarged cross-sectional view showing the welded portion between the spout and the laminated film. [Figure 6] Figure 6 (a) to (c) are cross-sectional views and top views that schematically show a method for producing the spout-equipped packaging bag shown in Figure 1, and are figures that sequentially show the steps of welding the laminated film to the spout (base). [Figure 7] 7(a) to 7(c) are cross-sectional views that schematically show a method for producing a spout-equipped packaging bag according to a comparative example, and sequentially show steps for welding a laminated film to a spout (base). DETAILED DESCRIPTION OF THE INVENTION

[0018] A spout-equipped packaging bag according to one embodiment of the present invention will be described in detail below with reference to the drawings. In the description, the same elements or elements having the same functions may be designated by the same reference numerals, and redundant description will be omitted. Note that the present invention is not limited to the following embodiment.

[0019] FIG. 1 is a plan view showing a spout-equipped packaging bag according to one embodiment. As shown in FIG. 1, the spout-equipped packaging bag 1 includes a storage section 10 made of a mono-material laminated film and a spout 20 attached to an upper end 11 (edge) of the storage section 10. The storage section 10 constitutes the bag portion of the spout-equipped packaging bag 1, and is configured such that a storage area 15 for the contents is enclosed by an upper end 11, a lower end 12, and side sections 13 and 14 formed by welding (sealing) sealant layers 18 (see FIG. 2(a)) of the laminated film 16 together. Liquid detergent, shampoo, etc., are stored within the storage area 15 of the storage section 10. The contents stored in the storage section 10 can be poured out through the spout 20. Such a spout-equipped packaging bag may be a so-called standing pouch.

[0020] 2(a) and 2(b) are diagrams showing cross sections of a laminate film constituting the storage section 10 of the spout-equipped packaging bag 1. As shown in FIG. 2(a), the laminate film 16 constituting the storage section 10 is a mono-material laminate film having a substrate 17 and a sealant layer 18 made of the same material. The substrate 17 and the sealant layer 18 may be made of the same material, such as polyethylene resin or polypropylene resin. To form the storage section 10 from the laminate film 16, multiple sheets of such laminate film 16 (e.g., a pair of laminate films) are prepared, and the upper end 11, lower end 12, and side portions 13 and 14 are welded together with the sealant layer 18 facing inward to form a bag shape as shown in FIG. 1. The laminate film constituting the storage section 10 may be a laminate film 16A including two substrate layers 17A and 17B and a sealant layer 18, as shown in FIG. 2(b). The laminate film 16A is a laminate film having a mono-material structure, as described above, and the substrates 17A and 17B and the sealant layer 18 are made of the same material. Note that the term "same material" does not mean only materials that are completely the same, but also includes films whose main constituent materials are the same.

[0021] [Base material] The substrates 17, 17A, and 17B are made of, for example, polyethylene resin or polypropylene resin. When the substrates 17, 17A, and 17B are unstretched polyethylene resin films, the resin has almost no orientation, making them easily stretchable and less likely to break under external stresses such as tension or shear. When the substrates 17, 17A, and 17B are stretched polyethylene resin films, they have excellent puncture resistance. The substrates 17, 17A, and 17B may be biaxially stretched polyethylene resin films. The thickness of the substrates 17, 17A, and 17B is, for example, 5 to 800 μm, or may be 5 to 500 μm or 10 to 50 μm. The substrates 17, 17A, and 17B may have a melting point that is 20° C. or more higher than that of the sealant layer 18, and preferably 25° C. or more higher. The difference in melting points between the substrates 17, 17A, and 17B can prevent the substrates 17, 17A, and 17B from melting during the heat-sealing process. The difference in seal rise temperature between the substrates 17, 17A, 17B and the sealant layer 18 is preferably 25°C or more, more preferably 30°C or more. The seal rise temperature refers to the temperature at which seal strength is developed. The melting point of the polyethylene resin can be measured using a differential scanning calorimeter (DSC).

[0022] The melting point of the substrates 17, 17A, and 17B is, for example, within a range of 100 to 170°C, preferably 120°C or higher, and more preferably 125°C or higher. Examples of polyethylene constituting the substrates 17, 17A, and 17B include high-density polyethylene (HDPE) and medium-density polyethylene (MDPE). Of these, HDPE and MDPE with a density of 0.925 g / cm are preferred from the viewpoint of heat resistance. 3 It is preferable to use a material having a density of 0.93 to 0.98 g / cm or more. 3 It is preferable to use high density polyethylene in the range of

[0023] The polyethylene resin constituting the substrates 17, 17A, and 17B is not limited to petroleum-derived resins, and may be partially or entirely biologically derived resin materials (for example, biomass polyethylene using biomass-derived ethylene as a raw material). A method for producing biomass-derived polyethylene is disclosed, for example, in JP-A 2010-511634. The substrates 17, 17A, and 17B may contain commercially available biomass polyethylene (such as Green PE manufactured by Braskem), or may contain mechanically recycled polyethylene made from used polyethylene products or resin (so-called burrs) generated during the manufacturing process of polyethylene products.

[0024] The substrates 17, 17A, and 17B may contain components other than polyethylene resin. Examples of such components include polyamide, polyethylene terephthalate, polypropylene, polyvinyl alcohol, and biodegradable resin materials (e.g., polylactic acid, polycaprolactone, polyhydroxyalkanoate, polyglycolic acid, modified polyvinyl alcohol, casein, and modified starch). The substrates 17, 17A, and 17B may contain additives such as antistatic agents, ultraviolet absorbers, plasticizers, lubricants, and colorants. The amount of components other than polyethylene resin in the substrates 17, 17A, and 17B is preferably 15% by mass or less, and more preferably 10% by mass or less, based on the total amount of the substrates 17, 17A, and 17B.

[0025] [Sealant layer] The sealant layer 18 is made of a polyethylene resin film, similar to the base materials 17, 17A, and 17B. That is, the sealant layer 18 is made of the same material as the base materials 17, 17A, and 17B. Note that the term "same material" as used herein means that the main resin (e.g., polyethylene resin) is the same, and also includes cases where the components contained other than the main resin are different. The thickness of the sealant layer 18 is, for example, 40 to 150 μm, and may be 20 to 250 μm. The polyethylene resin film constituting the sealant layer 18 is a film that has been given easy tearing properties in the machine direction (MD).

[0026] The polyethylene resin constituting the sealant layer 18 having such easy-tear properties is preferably, for example, C4-LLDPE. C4-LLDPE is a type of LLDPE (linear low-density polyethylene) made from a copolymer of ethylene and 1-butene, and has a molecular structure in which a 1-butene-derived side chain with four carbon atoms is attached to the ethylene-derived LLDPE main chain. C4-LLDPE has shorter side chains and a lower melt flow rate (MFR) than C6-LLDPE and C8-LLDPE, and therefore has relatively low tensile impact strength, tensile strength, and tensile modulus. Therefore, by using C4-LLDPE as the polyethylene resin constituting the sealant layer 18, it is possible to easily impart easy-tear properties to the sealant layer 18 in the machine direction.

[0027] The melt flow rate (MFR) of the sealant layer 18 is less than 5 g / 10 min, preferably 0.5 g / 10 min or more but less than 5 g / 10 min, and more preferably 2 g / 10 min or more but less than 5 g / 10 min. A melt flow rate of less than 5 g / 10 min increases the melt tension, which has the effect of making it easier to suppress wrinkles during processing by an inflation method or the like. In other words, the sealant layer 18 is somewhat less likely to flow when heated to melt it, allowing for a smooth and transparent film.

[0028] The melting point of the sealant layer 18 is, for example, in the range of 100 to 170° C., preferably 120° C. or less, and more preferably 95 to 110° C. The sealant layer 18 has a density of 0.925 g / cm 3 Less than (more preferably 0.900 to 0.920 g / cm 3 As an example, the above-mentioned linear low density polyethylene (LLDPE) can be used, and very low density polyethylene (VLDPE) or a blend of LLDPE and VLDPE may also be used as long as it can impart easy tearing properties to the sealant layer 18 in the machine direction.

[0029] Biomass polyethylene, which uses biomass-derived ethylene as a raw material, may be used as part or all of the polyethylene constituting sealant layer 18. Such a sealant film is disclosed, for example, in JP 2013-177531 A. Sealant layer 18 may contain mechanically recycled polyethylene, which is made from used polyethylene products or resin (so-called burrs) generated during the manufacturing process of polyethylene products.

[0030] (Other layers) The laminated film 16, 16A may have an adhesive layer (not shown) between the base material 17, 17A, 17B and the sealant layer 18. The adhesive forming the adhesive layer can be selected depending on the bonding method, and examples thereof include urethane adhesives and polyester adhesives. By providing such an adhesive layer, the interlayer adhesion between the base material 17, 17A, 17B and the sealant layer 18 is increased, making delamination less likely, and the pressure resistance and impact resistance of the pouch can be maintained.

[0031] The adhesive layer preferably does not contain chlorine. The absence of chlorine in the adhesive layer can prevent the adhesive or recycled resin from becoming discolored or from generating odors due to heat treatment. From an environmental perspective, it is preferable to use a biomass material for the adhesive layer. Furthermore, biomass polyethylene can be used for the polyethylene. From an environmental perspective, it is preferable that the adhesive does not contain a solvent.

[0032] The laminated film 16, 16A may further include a gas barrier layer, for example, from the viewpoint of improving gas barrier properties against water vapor and oxygen. The gas barrier layer may be provided between the substrate 17, 17A, 17B and the sealant layer 18, or may be provided on the surface of the substrate 17, 17A, 17B opposite to the sealant layer 18. The water vapor permeability of the laminated film is, for example, 5 g / m 2 day, 1g / m 2 ·day or less or 0.5g / m 2 The oxygen permeability of the laminated film 16, 16A may be, for example, 1 cc / m2 ·atm·day and 0.5g / m 2 ·atm·day or less or 0.2g / m 2 The laminated film 16, 16A may contain a gas barrier layer, which protects the contents from deterioration due to water vapor and oxygen, making it easier to maintain quality over the long term.

[0033] An example of a gas barrier layer is a vapor-deposited layer of an inorganic oxide. By using a vapor-deposited layer of an inorganic oxide, high barrier properties can be achieved with a very thin layer that does not affect the recyclability of the laminate. Examples of inorganic oxides include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. From the viewpoint of transparency and barrier properties, the inorganic oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. The thickness of the vapor-deposited layer of an inorganic oxide can be, for example, 5 nm to 100 nm, or 10 nm to 50 nm. A thickness of 5 nm or more facilitates the exertion of good barrier properties, while a thickness of 100 nm or less facilitates the maintenance of flexibility of the laminate. The vapor-deposited layer can be formed, for example, by physical vapor deposition, chemical vapor deposition, or the like.

[0034] The laminated film 16, 16A may include a metal layer (metal foil) instead of or in addition to the inorganic oxide vapor deposition layer. Various metal foils made of aluminum, stainless steel, etc. can be used as the metal layer. Among these, aluminum foil is preferred from the viewpoints of moisture resistance, processability such as ductility, cost, etc. Ordinary soft aluminum foil can be used as the aluminum foil. Among these, iron-containing aluminum foil is preferred from the viewpoints of pinhole resistance and ductility during molding. When a metal layer is provided, its thickness may be 7 to 50 μm or 9 to 15 μm from the viewpoints of barrier properties, pinhole resistance, processability, etc.

[0035] The laminated film 16, 16A may have an anchor coat layer between the substrate 17, 17A, 17B and the sealant layer 18. The anchor coat layer may be a very thin layer that does not affect the recyclability of the laminated film 16, 16A, and can be formed using an anchor coat agent. Examples of anchor coat agents include acrylic resins, epoxy resins, acrylic urethane resins, polyester polyurethane resins, polyether polyurethane resins, and polyvinyl alcohol resins. From the viewpoints of heat resistance and interlayer adhesive strength, acrylic urethane resins and polyester polyurethane resins are preferred as anchor coat agents.

[0036] The laminated film 16, 16A may further include, for example, a printed layer. The printed layer may be provided between the substrate 17, 17A, 17B and the sealant layer 18, or may be provided on the surface of the substrate 17, 17A, 17B opposite the sealant layer 18. When a printed layer is provided, it is preferable to use a printing ink that does not contain chlorine, from the viewpoint of preventing the printed layer from discoloring or generating an odor when remelted. Furthermore, from the viewpoint of environmental consideration, it is preferable to use a biomass material as the compound contained in the printing ink.

[0037] Next, with reference to FIGS. 1 and 3, a spout 20 attached to the upper end 11 of the storage section 10 made of the laminated film 16 will be described. The same applies when the laminated film 16A is used. FIG. 3(a) is a front view showing the spout 20 used in the spout-equipped packaging bag 1, and FIG. 3(b) is a view of the spout 20 as seen from below (the base side). As shown in FIGS. 1 and 3, the spout 20 has a pouring tube 21 extending in one direction (the vertical direction in FIGS. 1 and 3(a)), a base 22 provided on one end (lower end) of the pouring tube 21, a flange 23 provided between the pouring tube 21 and the base 22, and a cap 24 that screws onto a male thread provided on the outside of the pouring tube 21 to close the other end (upper end) of the pouring tube 21. A pouring passage 25 is provided through the center of the inside of the pouring tube 21 from the upper end to the lower end of the base 22. This allows the contents filled in the spouted packaging bag 1 to be poured out of the bag. The spout 20 can be made of, for example, polyethylene resin, similar to the laminated film 16 described above.

[0038] As shown in Fig. 3(b), the base 22 has, for example, a triangular portion 23a and an arc-shaped portion 23b, and the above-mentioned pouring channel 25 is formed inside them. When the spout 20 is attached to the storage portion 10, the base 22 is the portion to which the sealant layer 18 of the laminate film 16 is welded, and the sealant layers 18 of the pair of laminate films 16 are welded to each other on both sides of the base 22. A plurality of ribs that support the welding of the sealant layer 18 may be provided on the surface side of the base 22 to which the sealant layer 18 is welded. Such ribs may extend, for example, in the horizontal direction (circumferential direction).

[0039] Here, the configuration of the area where the spout 20 is welded to the laminated film 16 will be described with reference to Figure 4. Figure 4(a) is an enlarged front view of the spout-equipped packaging bag 1 near the welded portion of the spout 20, and Figure 4(b) is a cross-sectional view of the area near the welded portion of the spout. As shown in Figure 4, in the spout-equipped packaging bag 1 according to this embodiment, the sealant layer 18 of the laminated film 16 is welded to the base 22 of the spout 20 at the upper end 11 of the containing section 10, and the sealant layers 18 are welded to each other at the sides (both edges) of the base 22. That is, when welding the spout 20, the sealant layers 18 are welded to both the front and back sides of the spout 20, and on both sides of the spout 20, these opposing sealant layers 18 are directly welded to each other. In the spout-equipped packaging bag 1 according to this embodiment, the sealant layer 18 is welded to the base 22 in the welding region R1, and the sealant layers 18 are welded to each other in the welding region R2. The width of the welding region R1 and the width of the welding region R2 may be different, or the width of the welding region R1 may be shorter than the width of the welding region R2, forming a step S between them.

[0040] 5, the welding state of the laminate film 16 to the base 22 of the spout 20 in the welding region R1 will be described. FIG. 5 is an enlarged cross-sectional view showing the welded portion between the spout 20 and the laminate film 16. FIG. 5 shows only one side of the laminate film 16 to be welded; the other side is not shown, but is welded in the same manner. As shown in FIG. 5, in this welded portion, a resin reservoir 22b is formed in part of a melted portion 22a on the outer periphery of the base 22 of the spout 20 due to melting during welding. In the spout-equipped packaging bag 1 according to this embodiment, the resin reservoir 22b is positioned inward (toward the pouring tube 21, to the right in the figure) from an end 22c of the containing section 10 that is more susceptible to internal pressure. Furthermore, a protrusion 16a that protrudes outward is formed on the laminate film 16 at the end 22c, and the thickness D1 of the laminate film 16 at the end 22c is 70% or more of the thickness D2 of the unwelded portion 16b of the laminate film 16. The thickness D1 of the laminate film 16 at the end 22c may be 75% or more, 80% or more, 90% or more, or 100% or more of the thickness D2 of the unwelded portion 16b of the laminate film 16.

[0041] Next, an example of a method for manufacturing a spout-equipped packaging bag 1 having such a welded portion configuration will be described. In this manufacturing method, a laminate film 16 (or a pair of laminate films 16) including a substrate 17 and a sealant layer 18 made of the same material is prepared, and a spout 20 (see FIG. 3) having a pouring tube 21 and a base 22 provided on one end side of the pouring tube 21 is also prepared. Then, as shown in FIG. 6(a), first, the base 22 of the spout 20 is heated by a first heater 30. This melts the outer periphery of the base 22 or ribs or the like provided on the outer periphery. This forms a melted portion 22a on the outer periphery of the base 22. After the spout 20 is preheated, as shown in FIG. 6(b), the laminate film 16 is placed on the base 22 of the spout 20. Then, a second heater 31 (heating member) is pressed against the base 22 at a position shifted toward the pouring tube 21 (inside) from the end 22c of the base 22 opposite the pouring tube 21, thereby welding the laminate film 16 to the base 22 and forming a first welded body S1. The heat sealing temperature is equal to or higher than the melting point of the sealant layer 18, for example, in the range of 120 to 170°C. In the first welded body S1, a resin reservoir 22b is formed near the tip 31a of the second heater 31, where a portion of the base 22 is melted. Furthermore, a protrusion 16c is formed above the resin reservoir 22b of the laminate film 16. The resin reservoir 22b and the protrusion 16c are formed so as to be spaced inward from the end 22c (lower end) of the base 22.

[0042] After the first welded body S1 is formed, in this manufacturing method, as shown in FIG. 6(c), a third heater 32 (heating member) is pressed against a region of the first welded body S1 that includes at least the resin reservoir portion 22b, further welding the laminated film 16 to form a second welded body S2. The heat-sealing temperature at this time is also a temperature equal to or higher than the melting point of the sealant layer 18, for example, in the range of 120 to 170°C. This causes the protruding portion 16c of the laminated film 16 to move outward (to the left in the figure), increasing the thickness D1 of the laminated film 16 at the end 22c. That is, the laminated film 16 is welded to the spout 20 so that the thickness D1 of the laminated film 16 at the end 22c opposite the dispensing tube 21 in the welding region R1 where the sealant layer 18 is welded to the base 22 is 70% or more (for example, 100% or more) of the thickness D2 of the unwelded portion 16b of the laminated film 16. In this portion, since there is no resin reservoir 22b of the base 22 below, the thickness D1 of the laminate film 16 can be increased without being hindered. This two-stage welding method forms a spout welded portion having the cross-sectional configuration shown in FIGS. 4 and 5. The manufacturing method for achieving the thickness D1 of the laminate film 16 described above is not limited to the above method. For example, the second heater 31 may be used to melt a laminate film 16 that has been pre-processed to have a shape similar to that of the first welded body S1. The outer peripheral shape of the base 22 of the spout 20 may also be modified so that the thickness D1 of the laminate film 16 has the above-described thickness ratio.

[0043] The upper end 11, lower end 12 and side portions 13, 14 of the containing section 10 can be formed by welding the corresponding portions of the opposing sealant layers 18. When the spouted packaging bag 1 is a standing pouch, in addition to the pair of laminated films 16, a bottom film (having the same layer structure as the laminated film 16) that is folded in half and provided with a mountain fold may be placed on the lower end side and welded. In this case, the spouted packaging bag 1 can be made into a standing pouch that is a self-standing packaging bag. In this way, the spouted packaging bag 1 shown in Figure 1 is produced.

[0044] Here, the spout-equipped packaging bag 1 according to this embodiment and its manufacturing method will be described in comparison with a comparative example shown in Fig. 7 in which a spout welding portion is formed using a mono-material laminate film. Fig. 7(a) to (c) are cross-sectional views schematically illustrating a method for manufacturing a spout-equipped packaging bag according to the comparative example, sequentially illustrating the steps of welding a laminate film to a spout (base). In the comparative example, as shown in Fig. 7(a), a mono-material laminate film 116 is placed on a base 122 of a preheated spout 120 and heat-welded using a heating device 130. At this time, the heating device 130 heats up to a region including an end 122c of the base 122, and as shown in Figs. 7(b) and 7(c), a portion of a melted portion 122a of the base 122 during preheating protrudes near the end 122c as a resin reservoir 122b. As a result, the thickness of laminated film 116 at end 122c becomes much thinner than the thickness of the unwelded portion. For this reason, in the spouted packaging bag according to the comparative example, if the packaging bag is dropped after the contents are sealed in, laminated film 116 welded to base 122 may tear near end 122c.

[0045] In contrast, the spout-equipped packaging bag 1 according to this embodiment uses a mono-material laminate film 16, but the thickness D1 of the laminate film 16 at the end 22c (lower end) opposite the pouring tube 21 in the welded region R1 where the sealant layer 18 is welded to the base 22 is 70% or more of the thickness D2 of the unwelded portion 16b of the laminate film 16. With this configuration, according to this embodiment, even when a mono-material laminate film 16 is used, the drop resistance of the spout-equipped packaging bag 1 can be improved.

[0046] In the spout-equipped packaging bag 1 according to this embodiment, the thickness D1 of the laminate film 16 at the end 22c of the welded region R1 may be 100% or more of the thickness D2 of the unwelded portion 16b of the laminate film 16. In this case, even when a laminate film 16 having a mono-material configuration is used, the drop resistance of the spout-equipped packaging bag 1 can be further improved.

[0047] In the spout-equipped packaging bag 1 according to this embodiment, the base 22 of the spout 20 does not have a resin reservoir 22b formed by melting the spout 20 near the end 22c of the welded region R1. This prevents the laminate film 16 from becoming thinner due to the influence of the resin reservoir 22b, ensuring that the laminate film 16 at the end 22c of the base 22 of the spout 20 has a sufficient thickness. Furthermore, the resin reservoir 22b, which is a portion that may cause the spout-equipped packaging bag 1 to break if dropped, is not present at the end 22c. From the above, the drop resistance of the spout-equipped packaging bag 1 can be reliably improved even when a mono-material laminate film 16 is used.

[0048] In the spout-equipped packaging bag 1 according to this embodiment, the same material constituting the base material 17 and sealant layer 18 of the laminate film 16 is preferably a polyethylene resin or a polypropylene resin. This can improve the recyclability of the spout-equipped packaging bag. Furthermore, in the spout-equipped packaging bag 1, the same material constituting the base material 17 and sealant layer 18 of the laminate film 16 is preferably a polyethylene resin, and the content of polyethylene resin in the entire laminate film 16 is preferably 90% by mass or more. This can improve the recyclability of the spout-equipped packaging bag.

[0049] In the method for manufacturing a spout-equipped packaging bag according to this embodiment, when attaching the laminate film 16 to the spout 20, the laminate film 16 is welded so that the thickness D1 of the laminate film 16 at the end 22c opposite the pouring tube 21 in the welded region R1 where the sealant layer 18 is welded to the base 22 is 70% or more of the thickness D2 of the unwelded portion 16b of the laminate film 16. By ensuring that the thickness of the laminate film 16 at the end 22c (lower end) of the base 22 of the spout 20 is sufficient in this way, this manufacturing method makes it possible to easily manufacture a spout-equipped packaging bag 1 with improved drop resistance even when using a mono-material laminate film 16. Furthermore, when attempting to manufacture a spout-equipped packaging bag using a mono-material laminate film 16 as in the conventional configuration, the conditions (condition range of welding (sealing) temperature) for manufacturing a spout-equipped packaging bag with high drop resistance are extremely narrow, resulting in reduced productivity. However, with this manufacturing method, the range of manufacturing conditions for making the drop resistance of the packaging bag above a predetermined value can be widened, thereby improving productivity and increasing the rate of non-defective products.

[0050] In the method for manufacturing a spout-equipped packaging bag according to this embodiment, when attaching the spout 20 to the laminated film 16, the laminated film 16 is placed on the base 22 of the spout 20, and then the second heater 31 is pressed against a position shifted from the end 22c of the base 22 opposite the dispensing tube 21 toward the dispensing tube 21 to weld the laminated film 16 to form a first welded body S1, and then the third heater 32 is pressed against a region including at least the resin reservoir 22b of the first welded body S1 to further weld the laminated film 16 to form a second welded body S2. The resin reservoir 22b is created by melting a part of the base 22 (such as a rib) near the tip 31a of the second heater 31. According to this manufacturing method, it is possible to easily set the thickness D1 of the laminate film 16 at the end 22c of the welding region R1 where the sealant layer 18 is welded to the base 22 to 70% or more, preferably 100% or more, of the thickness D2 of the unwelded portion 16b of the laminate film 16. Therefore, according to this manufacturing method, even when a laminate film 16 having a mono-material configuration is used, a spout-equipped packaging bag with improved drop resistance can be easily produced.

[0051] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments. For example, in the above embodiments, the spout 20 is provided in the center of the upper end 11 of the storage section 10, but the present invention is not limited to such a configuration. For example, the spout 20 may be provided at the corner between the upper end 11 and the side section 13 of the storage section 10. Even with such a configuration, the same effects can be achieved. [Example]

[0052] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0053] Example 1 As Example 1, ten spout-equipped packaging bags 1 having the configuration shown in FIG. 1 were produced. The pouch size was 200 × 300 mm. The mono-material laminate film 16A used had a three-layer configuration as shown in FIG. 2(b), with the substrate 17A being 30 μm thick HDPE, the substrate 17B being 32 μm thick HDPE, and the sealant layer 18 being 100 μm thick LLDPE. The thickness D1 of the laminate film 16A at the end 22c of the base 22 of this spout-equipped packaging bag 1 was 143 μm, and the thickness D2 of the unwelded portion of the laminate film 16A was 162 μm. In other words, the thickness D1 of the laminate film 16A was 88% of the thickness D2. The heat-sealing temperature used to weld the laminate film 16 to the base 22 of the spout 20 was 20°C higher than the normal heating temperature.

[0054] Thereafter, 1200 ml of cold water at 5°C was sealed in the storage section 10 of each sample of the spouted packaging bag 1 according to Example 1. Then, each sample of the packaging bag was dropped horizontally from a height of 1 m so that the surface of the spouted packaging bag 1 faced upward. In this horizontal drop test, it was confirmed whether the dropped spouted packaging bag 1 broke (particularly whether it broke near the base 22). It was confirmed that none of the 10 test samples of the spouted packaging bag 1 according to Example 1 broke.

[0055] <Example 2> In Example 2, ten spout-equipped packaging bags 1 having the configuration shown in FIG. 1 were produced in the same manner as in Example 1, except that welding was performed under conditions in which the heat sealing temperature was increased by 30°C above the normal heating temperature. The thickness D1 of the laminated film 16A in Example 2 was 131 μm, and the thickness D2 of the unwelded portion of the laminated film 16A was 162 μm. In other words, the thickness D1 of the laminated film 16A was 81% of the thickness D2. Thereafter, a horizontal drop test similar to that in Example 1 was carried out. It was confirmed that none of the ten test samples of the spout-equipped packaging bag 1 according to Example 2 broke.

[0056] <Comparative Example 1> In Comparative Example 1, ten spout-equipped packaging bags were produced using the same mono-material laminate film as in Example 1, but by the conventional method shown in FIG. 7 . The heat-sealing temperature when welding the laminate film to the spout base was 20°C higher than the normal heating temperature. The thickness D1 of the laminate film 16A in Comparative Example 1 was 95 μm, and the thickness D2 of the unwelded portion of the laminate film 16A was 162 μm. In other words, the thickness D1 of the laminate film 16A was 59% of the thickness D2. Thereafter, a horizontal drop test similar to that in Example 1 was conducted. Five of the ten test samples of the spout-equipped packaging bag according to Comparative Example 1 were broken.

[0057] <Comparative Example 2> In Comparative Example 2, ten spout-equipped packaging bags were produced in the same manner as in Comparative Example 1, except that the heat sealing temperature was increased by 30°C above the normal heating temperature. The thickness D1 of the laminated film in Comparative Example 2 was 80 μm, and the thickness D2 of the unwelded portion of the laminated film 16A was 162 μm. In other words, the thickness D1 of the laminated film 16A was 49% of the thickness D2. A horizontal drop test similar to that in Comparative Example 1 was then conducted. Of the ten spout-equipped packaging bags according to Comparative Example 2, nine were broken.

[0058] <Comparative Example 3> As Comparative Example 3, ten spout-equipped packaging bags were produced by performing only the welding shown in (a) and (b) of FIG. 6 (i.e., without performing the second-stage re-welding shown in (c) of FIG. 6) of the manufacturing method shown in FIG. 6. The mono-material laminate film 16A used in Comparative Example 3 had a three-layer structure shown in (b) of FIG. 2, in which the substrate 17A was HDPE with a thickness of 30 μm, the substrate 17B was HDPE with a thickness of 32 μm, and the sealant layer 18 was LLDPE with a thickness of 120 μm. The thickness D1 of the laminate film 16A in Comparative Example 3 was 82 μm, and the thickness D2 of the unwelded portion of the laminate film 16A was 182 μm. That is, the thickness D1 of the laminate film 16A was 45% of the thickness D2. The heat-sealing temperature was increased by 20°C from the normal heating temperature. Thereafter, a horizontal drop test similar to that of Example 1 was performed. In the spout-equipped packaging bag according to Comparative Example 3, 6 out of 10 test samples were broken.

[0059] <Comparative Example 4> In Comparative Example 4, ten spout-equipped packaging bags were produced in the same manner as in Comparative Example 3, except that the heat sealing temperature was increased by 30°C above the normal heating temperature. The thickness D1 of the laminated film in Comparative Example 4 was 77 μm, and the thickness D2 of the unwelded portion of the laminated film 16A was 182 μm. In other words, the thickness D1 of the laminated film 16A was 42% of the thickness D2. Thereafter, a horizontal drop test similar to that in Comparative Example 3 was carried out. Of the ten test samples of the spout-equipped packaging bag according to Comparative Example 4, nine were broken.

[0060] Table 1 below shows the results of the horizontal drop test and the ratio of the thickness D1 / D2 of the laminated film. [Table 1]

[0061] As can be seen from Examples 1, 2 and Comparative Examples 1 to 4, the thickness D1 of the laminated film 16 at the end 22c opposite the dispensing tube 21 in the welded region R1 where the sealant layer 18 is welded to the base 22 is 70% or more of the thickness D2 of the unwelded portion 16b of the laminated film 16, and it has been confirmed that the drop resistance of the spout-equipped packaging bag is improved even when a mono-material laminated film is used. [Explanation of symbols]

[0062] 1...packaging bag with spout, 10...storage section, 11...upper end (edge), 16, 16A...laminated film, 16b...unwelded section, 17, 17A, 17B...base material, 18...sealant layer, 20...spout, 21...pouring tube, 22...base, 22b...resin reservoir section, 22c...end, D1, D2...thickness, R1...welded area.

Claims

1. a storage portion formed of a laminated film including a base material and a sealant layer made of the same material; A spout having a pouring tube and a base provided on one end side of the pouring tube and attached to an edge of the storage portion, At the edge of the storage portion, the sealant layer is welded to the base of the spout, and the sealant layers are welded to each other next to the base, A packaging bag with a spout, wherein the thickness of the laminated film at the end of the welded area where the sealant layer is welded to the base opposite the pouring tube is 70% or more of the thickness of the unwelded portion of the laminated film.

2. the thickness of the laminate film at the end of the welded region is 100% or more of the thickness of the unwelded portion of the laminate film; The spout-equipped packaging bag according to claim 1.

3. The base of the spout does not have a resin reservoir where the spout is melted near the end of the welding region. The spout-equipped packaging bag according to claim 1.

4. The laminated film includes a pair of laminated films, The spout is attached to one end of the pair of laminated films, the storage section has a bottom film including a base material and a sealant layer made of the same material as the pair of laminated films and having a mountain fold; The bottom film is welded to the other end of the pair of laminated films to form a self-standing packaging bag. The spout-equipped packaging bag according to any one of claims 1 to 3.

5. The same material constituting the substrate and the sealant layer of the laminated film is a polyethylene resin or a polypropylene resin. The spout-equipped packaging bag according to any one of claims 1 to 3.

6. the same material constituting the base material and the sealant layer of the laminated film is a polyethylene resin, The content of polyethylene resin in the entire laminated film is 90% by mass or more. The spout-equipped packaging bag according to any one of claims 1 to 3.

7. preparing a laminated film including a substrate and a sealant layer made of the same material; A step of preparing a spout having a pouring tube and a base provided on one end side of the pouring tube; and a step of attaching the laminated film to the spout by welding the sealant layer to the base of the spout and welding the sealant layers to each other next to the base. In the attaching step, the laminate film is welded so that the thickness of the laminate film at the end of the welded region where the sealant layer is welded to the base, on the opposite side to the pouring tube, is 70% or more of the thickness of the unwelded portion of the laminate film. A method for manufacturing a packaging bag with a spout.

8. The attaching step includes: a step of placing the laminated film on the base of the spout, and then pressing a heating member against a position shifted from an end of the base opposite to the pouring tube toward the pouring tube to weld the laminated film and form a first welded body, wherein a resin reservoir portion formed by melting a part of the base is formed near a tip of the heating member in the first welded body; and pressing a heating member against a region of the first welded body that includes at least the resin reservoir portion to further weld the laminated film to form a second welded body. A method for producing the spout-equipped packaging bag according to claim 7.

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