Composite container and method for manufacturing a composite container

Abstract

A composite container includes a paper container formed by combining a main body member and a bottom plate member; and a resin film attached to the inner surface of the paper container. In the paper container, the paper is exposed at a surface at which the paper container and the film are attached. In the paper container, a side coupling part for coupling a side surface of a main body member and a bottom coupling part for coupling the main body member and a bottom plate member are each coupled by a bonding agent. The film includes an adhesive layer for adhesion to the paper of the paper container.

Description

Technical Field

[0001] The present invention relates to a composite container having a film bonded to the inner surface of a paper container and a method of making the composite container. Background Art

[0002] Some composite containers may have an inner surface coated with resin to prevent the contents from leaking from the container's connection (see, for example, Patent Document 1). The container of Patent Document 1 is such that a preformed resin inner container is assembled into a paper outer container, and the opening edge of the inner container and the opening edge of the outer container are rolled outward together to form a curled portion. In other words, the inner container and the outer container are connected by forming a double curled portion together. The container of Patent Document 1 has a problem in that the amount of resin increases compared to a case where only a paper container is used, and the internal volume of the container is reduced due to the space between the outer container and the inner container.

[0003] In some other methods of manufacturing composite containers, a preform having a shape corresponding to the container opening is preformed by injection molding, and then attached to the inside of the container while stretching the preform by compressed air molding or vacuum molding (for example, see Patent Document 2). Although the manufacturing method of Patent Document 2 attaches a resin material to the inner surface of the container by compressed air molding of a heated resin preform, etc., there is no description of adhesion between the resin and paper.

[0004] In some other methods of manufacturing composite containers, a liner is adhered to the inside of a paper outer cup by vacuum suction, thereby covering the inner surface of the outer cup with the inner cup (for example, see Patent Document 3). In the manufacturing method of Patent Document 3, the bottom plate member of the container is intermittently connected to the lower portion of the container body member, and vacuum suction is performed through the non-connected portion between the bottom plate member and the container body member to adhere the liner to the entire inner surface of the container. In the manufacturing method of Patent Document 3, as an aid to vacuum suction, the liner is stretched by lowering the stopper while it is in contact with the liner. However, this requires adjusting the stopper's lowering speed, the degree of contact between the stopper and the liner, and so on.

[0005] Prior art literature

[0006] Patent Literature

[0007] [Patent Document 1] JP 2001-180641 A

[0008] [Patent Document 2] JP H03-176128A

[0009] [Patent Document 3] JP 2004-224422 A Summary of the Invention

[0010] The present invention has been invented in view of the above-mentioned background art, and an object of the present invention is to provide a composite container having a resin film stably adhered to the inner surface and a method of manufacturing such a composite container.

[0011] In one embodiment, a composite container includes: a paper container having a main body member and a bottom plate member joined together; and a resin film bonded to the inner surface of the paper container. The base paper of the paper container is exposed at the adhesive surface between the paper container and the film. With respect to the paper container, the side joints connecting the side surfaces of the main body member and the bottom joint connecting the main body member and the bottom plate member are both bonded via a bonding agent. The film includes an adhesive layer that adheres to the base paper of the paper container.

[0012] In one embodiment, a method for manufacturing a composite container is provided, wherein the composite container includes: a paper container having a main body member and a bottom plate member connected together; and a resin film bonded to the inner surface of the paper container. The base paper of the paper container is exposed at the adhesive surface between the paper container and the film, and the film includes an adhesive layer that adheres to the base paper of the paper container. The manufacturing method includes: a bonding agent applying step of applying a bonding agent to a portion of the inner surface of the paper container, the portion corresponding to the side connecting portion connecting the side surfaces of the main body member and the bottom connecting portion connecting the main body member and the bottom plate member; a bonding step of completing the corresponding bonding of the side connecting portion and the bottom connecting portion; and a film bonding step of bonding the film to the adhesive surface of the paper container using a pressure difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1A It is a conceptual cross-sectional view illustrating a composite container.

[0014] Figure 1B It is a development view showing the main body member of the composite container.

[0015] Figure 1C It is a partial enlarged cross-sectional view of the composite container.

[0016] Figure 2A and 2B It is an enlarged cross-sectional view of the periphery of the bottom connecting portion of the composite container.

[0017] Figure 3 This is a conceptual diagram illustrating the feeding of the blank of the main body member.

[0018] Figure 4A is a graph illustrating the thickness of a film bonded to a paper container.

[0019] Figure 4B : is a table illustrating implementation examples of film thickness.

[0020] Figure 5is a conceptual cross-sectional view illustrating a membrane bonding device used in the membrane bonding step.

[0021] Figure 6 is a flow chart illustrating a method for manufacturing a paper container.

[0022] 7A to 7C This is a conceptual diagram illustrating a method for manufacturing a paper container.

[0023] Figure 8A and Figure 8B is a table showing an implementation example of a composite container.

[0024] 9A to 9D It is a development view showing the application position of the bonding agent on the main body member related to the embodiment of the composite container.

[0025] Figures 10A to 10C 1 and 2 are diagrams illustrating modified examples of side application portions of the bonding agent at the side joints.

[0026] Figures 11A to 11E 1 and 2 are diagrams illustrating a modified example of a bottom application portion of a bonding agent in a bottom joint portion.

[0027] Figure 12A and Figure 12B 1 and 2 are diagrams illustrating a modified example of a bonding agent application portion in a bottom joint portion.

[0028] Figure 13 is a conceptual diagram illustrating a modified example of a composite container.

[0029] 14A to 14C is an enlarged sectional view illustrating an inlet portion of a composite container in a modified example.

[0030] Figure 15 It is an enlarged cross-sectional view of the periphery of the bottom connecting portion of the composite container in the modified example. DETAILED DESCRIPTION

[0031] Example

[0032] A description is given below of a container and a method of manufacturing the container according to the present invention with reference to the accompanying drawings.

[0033] Figure 1A is a cross-sectional view illustrating one example of the composite container 10 . Figure 1B yes Figure 1A FIG. 1 is an expanded view of a main body member 11 of a composite container 10 to be described below. Figure 1B In FIG, a portion to which a bonding agent HS to be described below is applied is indicated by a matte pattern. Figure 1C yes Figure 1A FIG. 1 is an enlarged view of a portion of the composite container 10 enclosed by the dotted line MA shown in FIG.

[0034] like Figure 1A As shown in FIG, a composite container 10 is a cup-shaped container having a resin film FL bonded to the entire inner surface IS of a paper container PC. The composite container 10 has an inlet portion PCa at the top that is a circular opening, and the side surface of the composite container 10 is tapered in the vertical direction. The composite container 10 includes a rolled portion PCb formed by rolling outward the peripheral portion of the opening.

[0035] The paper container PC is assembled by connecting the main body member 11 and the bottom plate member 12. The bottom portion P3 of the paper container PC is closed by the bottom plate member 12. The outer periphery 12c of the bottom plate member 12 has a peripheral wall 12b that is bent downward. The peripheral wall 12b is connected to the bottom portion 11b of the main body member 11. Figure 2A and Figure 2B As shown in an enlarged form in FIG, the bottom portion 11 b of the main body member 11 is bent inwardly at the bottom end, and the peripheral wall 12 b is sandwiched between the outer wall 11 ba and the inner wall 11 bb of the main body member 11.

[0036] About paper container PC, Figure 1B The connection at the side connection portion 13a shown in the figure and the connection at the bottom connection portion 13b are each achieved via a bonding agent HS. The side connection portion 13a is a portion that connects the side surface of the main body member 11 (hereinafter also referred to as the side portion SD). Here, the portion that connects the side surface of the main body member 11 refers to the end portions 3a, 3b of the side surface of the main body member 11, and the main body member 11 is formed into a cylindrical shape by combining the two end portions 3a, 3b so that the end portions 3a, 3b overlap each other. The side portion SD corresponds to the inner surface IS of the end portion 3a, which is one of the end portions 3a and 3b of the side surface of the main body member 11. The bonding agent HS is applied to the entire side portion SD, that is, the inner surface IS of one end portion 3a, to form a side application portion SS.

[0037] The bottom connecting portion 13b is a portion connecting the main body member 11 and the bottom plate member 12 (hereinafter also referred to as the bottom BT). With respect to the main body part 11, the portion connecting the main body member 11 and the bottom plate member 12 refers to the area of ​​the inner surface IS of the bottom portion 3c of the main body member 11 excluding the end portion 3a (side portion SD) of the side surface. The bonding agent HS is applied to a partial area of ​​the bottom BT to form a bottom application portion CC. Specifically, the bottom application portion CC is located at a plurality of positions in a regular cycle or interval. Each of the bottom application portions CC has, for example, a rectangular shape and has a uniform width or the same area. The area other than the bottom application portion CC in the bottom BT is referred to as a bottom non-application portion NC1, corresponding to the non-bonding portion NB, which will be described below. The bottom application portion CC includes a plurality of elongated shaped areas. Each of these areas is arranged substantially parallel to the vertical direction of the paper container PC. In Figure 1B In the developed view of FIG, the bottom application portion CC is arranged slightly radially along the bottom portion 3c.

[0038] Regarding the bottom BT, the bottom coating area of ​​the region where the binder HS is applied ranges from 26% to 80% of the total area of ​​the bottom BT. The bottom coating area is the area of ​​the bottom BT excluding the bottom non-application portion NC1, that is, the total area of ​​the plurality of bottom application portions CC. The number of bottom application portions CC is, for example, 20.

[0039] like Figure 2A and Figure 2B As shown in FIG, the bottom connecting portion 13b includes a portion containing the binder HS and a portion (non-bonding portion NB) not containing the binder HS. Figure 2B In the non-bonding portion NB shown in FIG, a portion of the bottom connecting portion 13b is provided with a vent AP that allows air to be discharged to the outside of the paper container PC. In other words, the vent AP is formed by the bottom non-applied portion NC1 to which the bonding agent HS is not applied. The non-bonding portion NB forms small gaps between the bottom portion 11b of the main body member 11 and the peripheral wall 12b of the bottom plate member 12, and these gaps are used as the vent AP. When the film FL is bonded to the inner surface IS of the paper container PC, the vent AP allows air to be discharged to the outside of the paper container PC by performing vacuum suction. This increases ventilation during vacuum suction, which improves the formability of the film FL.

[0040] Adhesive HS is also applied to the strip-shaped portion corresponding to the curled portion PCb of the paper container PC (hereinafter also referred to as the top TP). The top TP corresponds to the inner surface IS of the top portion 3d of the main body member 11. The entire top TP is coated with adhesive HS. The curled portion PCb is curled, rolling up the adhesive HS applied to the inner surface IS of the paper container PC.

[0041] As described above, a binder HS is applied to the side SD, bottom BT, and top TP of the blank of the main body member 11 to maintain the paper container PC in a cup shape. When applying the binder HS to the side SD and bottom BT, the binder HS can also be applied to the top TP at the same time. This reduces the number of processes. In addition, by partially applying the binder HS to the inner surface IS of the paper container PC, the amount of resin used to connect the parts of the paper container PC to each other can be reduced, which is environmentally friendly. This also makes it possible to define a portion on the base paper 14 that is in direct contact with the film FL of the inner surface IS of the paper container PC, which is called the adhesion surface BS. Since the exposed surface of the base paper 14 has better adhesion to the adhesive layer 16 described below of the film FL than the surface obtained by applying an ordinary laminate finish to the base paper 14, the adhesion between the paper container PC and the film FL is stable.

[0042] The binder HS applied to the top TP prevents the lubricant used during the processing of the curled portion PCb from penetrating the base paper 14 of the paper container PC. This effectively prevents the unwinding of the curled portion PCb. If the lubricant penetrates the base paper 14, the base paper 14 loses its rigidity and becomes difficult to curl, resulting in a container in which the curled portion PCb is not completely curled or a container in which the curled portion PCb is buckled. In addition, when the curled portion PCb is pressed with a hot plate (not shown), the binder HS is applied to the top TP corresponding to the curled portion PCb, effectively preventing the curled portion PCb from unfolding. In addition, by applying the binder HS to the top TP, it is possible to feed the blanks of the main body member 11 one by one when assembling the paper container PC. As Figure 3 As shown in FIG, the blanks are fed to the assembly device using a holding device (not shown) having a slit ST. In this case, the blanks can be fed one by one by evacuating the slit ST. When the portion of the paper overlapping the slit ST is air-permeable, the two blanks can be sucked in. By applying a binder HS to the top TP, the applied portion becomes less permeable to air, and the suction of the two blanks can be prevented. However, it should be noted that if the material of the top TP makes it difficult for air to pass through, it is not necessary to apply a binder HS.

[0043] Before assembling the paper container PC, a binder HS is applied to the blank of the main body member 11. The binder HS can be applied by printing, for example. The amount of the binder HS applied is, for example, 5 g / m 2 Up to 20g / m 2 .

[0044] The bonding agent HS may be, for example, a heat sealant, a pressure sensitive adhesive, etc. The types of bonding agent HS applied to the side portion SD, the bottom portion BT, and the top portion TP may be different.

[0045] The heat sealant may be, for example, a thermoplastic resin. Examples of thermoplastic resins include polyethylene and its modified resins, ionomer resins, ethylene-methacrylic acid copolymer resins, ethylene-acrylic acid copolymer resins, ethylene-vinyl acetate copolymer resins, styrene-acrylic acid copolymer resins, cellulose acetate resins, polyester resins, polylactic acid resins, polyhydroxyalkanoic acid resins, polybutylene succinate resins, polybutylene butyrate resins, hydroxybutyrate-hydroxyhexanoate copolymer resins, polyvinyl alcohol resins, ethylene-vinyl alcohol copolymer resins, polypropylene and its modified resins, polyhydroxybutyric acid resins, acrylic resins, methacrylic resins, polyethylene terephthalate resins, and polyamide resins. The heat sealant used is a material obtained by dispersing, dissolving, or emulsifying a thermoplastic resin in water or a solvent.

[0046] Examples of pressure-sensitive adhesives include modified vinyl acetate resin, vinyl acetate resin, acrylic modified vinyl acetate copolymer resin, vinyl copolymer resin, ethylene-vinyl acetate copolymer resin, urea-formaldehyde resin, melamine resin, phenol-formaldehyde resin, resorcinol resin, chloroprene rubber, epoxy resin, urethane resin, silicone resin, modified silicone resin, styrene-butadiene rubber copolymer resin, isobutylene-maleic anhydride copolymer resin, vinyl chloride resin, starch, nitrile rubber, rosin, acrylic resin, methacrylic resin, acrylate resin, methacrylate resin, etc.

[0047] like Figure 1C As shown in FIG, the paper container PC includes a base paper 14. The base paper 14 for the main body member 11 has a thickness of, for example, 150 to 400 g / m 2 The base paper 14 used for the bottom plate member 12 has a basis weight of, for example, 150 to 400 g / m 2 If the basis weight is less than 150g / m 2 Due to lack of rigidity, the container itself will not be able to stand on its own. If the basis weight is greater than 400g / m 2 , due to the excessive stiffness, it is impossible to form a top curl.

[0048] The composite container 10 is structured so that the base paper 14 of the paper container PC is exposed at the adhesive surface BS between the paper container PC and the film FL. A printed layer 15 that decorates the composite container 10 is formed on the outer surface OS of the base paper 14. The printed layer 15 displays information such as pictures and text, and the markings described below, by printing on the outer surface OS of the composite container 10. For example, overprint varnish (OP varnish), heat sealant, laminated finish can be used as the printed layer 15. This allows the composite container 10 to be waterproof. The printed layer 15 can be a combination of ink and OP varnish, a combination of ink and heat sealant, or a combination of ink and laminated finish. These combinations provide the above-mentioned waterproof effect and also prevent the ink from fading.

[0049] The printed layer 15 includes markings on the outer surface OS of the base paper 14 for applying the binder HS to predetermined locations on the inner surface IS of the base paper 14. These markings serve as a reference for applying the binder HS. Furthermore, the markings on the printed layer 15 serve as a reference when cutting the blank for the main member 11 based on the location of the binder HS on the inner surface IS of the base paper 14. In embodiments where the markings are replaced by another method, the printed layer 15 may be omitted.

[0050] The film FL is bonded to the adhesive surface BS, which is the inner surface IS of the base paper 14 of the paper container PC. In order to firmly bond the film FL to the paper container PC, as described above, the film FL needs to be in contact with the exposed portion of the base paper 14. The thickness of the film FL varies depending on the adhesion position to the paper container PC, wherein the film FL is adhered to the bottom portion P3 of the paper container PC (see FIG. Figure 1A ) than the portion of the film FL that adheres to the main body inner wall P2 (see Figure 1A ) portion. The thicker thickness of the film FL on the bottom portion P3 prevents small holes from being formed through the film FL when the composite container 10 is filled with sharp contents or when the composite container 10 is dropped. The thicker thickness of the film FL on the bottom portion P3 makes it less likely that the film will shrink due to the heat generated by the contents when heated in a microwave oven, thereby preventing peeling between the paper container PC and the film FL. The thicker thickness of the film FL on the bottom portion P3 brings the center of gravity of the composite container 10 closer to the bottom portion P3, making the composite container 10 less likely to tip over. It should be noted that according to the modification of the inner diameter of the inlet portion PCa of the paper container PC and the height of the paper container PC, the thickness of the film FL will be modified according to the adhesion position.

[0051] Figure 4A : is a diagram illustrating the thickness of the film FL bonded to the paper container PC. Figure 4B It is a table showing specific examples of the thickness of the illustrated film FL. The thickness of the film FL before bonding is 100 μm. The thickness is measured by a method using a micrometer or a method using a thickness gauge. The measurement points are four points at the circumference of the main body center E1 of the film FL, four points at the circumference of the V zone E2, and one point at the bottom center E3. The number of samples is 5, and the measurement values ​​shown in Figure 4 are average values. The measurement values ​​of the main body center E1 and the V zone E2 are obtained by averaging the values ​​of the four points of the main body center E1 and the four points of the V zone E2 of each sample, and further averaging the average values ​​of the five samples. The measurement value of the bottom center E3 is obtained by averaging the measurement value of one point of the bottom center E3 of the 5 samples. The V zone E2 corresponds to Figure 2A and Figure 2B The V zone VZ shown in FIG. The V zone VZ is a portion connecting the main body member 11 and the bottom plate member 12.

[0052] like Figure 1C As shown in FIG, the film FL has a three-layer structure. Specifically, the film FL includes an adhesive layer 16, an intermediate layer 17, and a base material layer 18 supporting the adhesive layer 16 and the intermediate layer 17 in this order from the adhesion surface BS of the base paper 14.

[0053] The base layer 18 is provided on the innermost portion of the composite container 10 and is in contact with the contents of the composite container 10. The base layer 18 has water resistance, chemical resistance, etc. The base layer 18 can be made of, for example, polypropylene (PP), polyethylene (PE), etc.

[0054] Intermediate layer 17 primarily inhibits the formation of pinholes. Examples of intermediate layer 17 include laminates of nylon (Ny) and ethylene vinyl alcohol resin (EVOH), or laminates of ionomer and EVOH. The elasticity and flexibility of Ny and ionomer prevent the formation of pinholes that penetrate the membrane FL. EVOH, with its gas barrier properties and oil resistance, functions as a barrier material. The use of intermediate layer 17 allows the membrane FL to be made thinner.

[0055] The adhesive layer 16 is a layer that adheres to the base paper 14 of the paper container PC. Figure 1A As shown in FIG, adhesive layer 16 adheres to the entire surface of the inlet portion PCa or flange P1, the inner wall P2 of the main body, and the bottom portion P3 of the paper container PC. However, adhesive layer 16 does not adhere to zone VZ. The adhesive properties of adhesive layer 16 allow paper fibers to adhere to film FL when it is peeled from base paper 14. Specifically, the adhesive strength of adhesive layer 16 ranges from 0.5 N / mm to a strength that causes paper delamination. The measured width for adhesion is 15 mm.

[0056] Examples of the adhesive layer 16 include polyolefins such as polypropylene and polyethylene, modified resins thereof, polyester resins such as polyvinyl chloride and polyethylene terephthalate, ethylene-vinyl acetate copolymer resin (EVA), ethylene-vinyl alcohol copolymer resin, polyamide resin, polyvinylidene chloride resin, polystyrene resin, polycarbonate resin, polybutylene resin, and polyvinyl alcohol resin, as well as other thermoplastic resins. Preferably, the adhesive layer 16 is made of a material having high adhesiveness so as to uniformly adhere to the base paper 14 of the paper container PC.

[0057] Examples of film FL configurations are listed below. The left side of the configuration example corresponds to the base paper 14, and the right side corresponds to the inner surface IS side of the composite container 10. In the configurations listed below, the molten thermoplastic resin is formed into a film and, unlike adhesives, does not disperse, dissolve, or emulsify in water or solvents. The combination of materials constituting the film FL can be modified as appropriate, as long as the film FL functions as the adhesive layer 16, the intermediate layer 17, and the base material layer 18.

[0058] Configuration example of membrane FL

[0059] (Base paper side) PE / EVOH / Ny / PP (Inner surface side of composite container)

[0060] (Base paper side) PP / EVOH / Ny / PP (Inner surface side of composite container)

[0061] (Base paper side) PE+PP / EVOH / Ny / PP (Inner surface side of composite container)

[0062] (Base paper side) EVA / EVOH / Ny / PP (Inner surface side of composite container)

[0063] (Base paper side) PE / EVOH / Ny / PE (Inner surface side of composite container)

[0064] (Base paper side) EVA / EVOH / Ny / PE (Inner surface side of composite container)

[0065] (Base paper side) PP / Ny / PP (Inner surface side of composite container)

[0066] (Base paper side) PE / Ny / PP (Inner surface side of composite container)

[0067] (Base paper side) PE+PP / Ny / P (Inner surface side of composite container)

[0068] (Base paper side) EVA / Ny / PP (Inner surface side of composite container)

[0069] (Base paper side) PE / Ny / PE (Inner surface side of composite container)

[0070] (Base paper side) EVA / Ny / PE (Inner surface side of composite container)

[0071] (Base paper side) EVA / EVOH / ionomer / PE (Inner surface side of composite container)

[0072] (Base paper side) PE / EVOH / ionomer / PE (Inner surface side of composite container)

[0073] (Base paper side) PP / EVOH / ionomer / PP (Inner surface side of composite container)

[0074] (Base paper side) PE / EVOH / ionomer / PP (Inner surface side of composite container)

[0075] (Base paper side) EVA / EVOH / ionomer / PP (Inner surface side of composite container)

[0076] (Base paper side) PE+PP / EVOH / ionomer / PP (Inner surface side of composite container)

[0077] The film FL is deformable along the inner surface IS of the paper container PC during compressed air forming and has a thickness sufficient to prevent pinholes. The total thickness of the film FL before bonding is, for example, 90 to 250 μm, preferably 100 μm. The total thickness of the base layer 18 and the intermediate layer 17 is, for example, 60 to 80 μm, and the thickness of the adhesive layer 16 is, for example, 20 to 40 μm. The composition ratio of the adhesive layer 16, the intermediate layer 17, and the base layer 18 is, for example,:

[0078] (Adhesive layer): (Intermediate layer + Base material layer) = 2:8 to 4:6, and

[0079] As long as the barrier properties, adhesive properties, etc. of the film FL are maintained, the composition ratio can also be appropriately changed. The performance of the film FL is significantly affected by its thickness and is less affected by its ratio. For example, the total thickness of the film FL affects whether the film FL will tear when the film FL is bonded. In addition, when the film FL contains Ny, EVOH or ionomer, the film FL is not easy to tear. The thickness of the adhesive layer 16 affects the adhesion between the film FL and the base paper 14. The effect of the thickness of the adhesive layer 16 also varies depending on the type of resin used in the adhesive layer 16. The oxygen barrier properties of the film FL are affected by the thickness of the EVOH that acts as an oxygen barrier.

[0080] Figure 5 The film bonding device 100 shown in FIG. 1 includes a lower mold member 20, a compressed air device 30, a support member 40, an air conditioner 50, an air suction unit 60, and a control device 80. The film bonding device 100 bonds the film FL or film material FM to the inner surface IS or the adhesion surface BS of the paper container PC using a pressure difference. As will be described in detail later, the pressure difference is generated by introducing compressed air from above the film FL or by vacuum suction from below the paper container PC.

[0081] The lower mold member 20 includes a cylindrical cavity 21, a disc-shaped base 22, and an annular film retaining member 23. The lower mold member 20 also includes a disc-shaped base 25 that secures the cavity 21 and base 22 in alignment with each other, and a support member 26 that secures the film retaining member 23 upward relative to the outer periphery of the base 25. A paper container PC, serving as the material to be processed, is stably supported within the lower mold member 20 by the cavity 21 and the base 22. A gap GA is formed between the inner surface of the lower portion of the cavity 21 and the periphery of the base 22, and ventilation paths 28a and 28b are formed through the bottom portion of the base 22. Air surrounding the paper container PC can be evacuated to the air suction unit 60 through the gap GA and the ventilation paths 28a and 28b.

[0082] The compressed air device 30 is a disc-shaped member having a heater 31 and a plurality of vents 33 incorporated therein. The compressed air device 30 has an annular cutter 35 fixed at its outer periphery for cutting a workpiece portion FLa to be bonded to the inner surface IS of the paper container PC from the sheet-like film material FM moving over the lower mold member 20. The workpiece portion FLa corresponds to Figure 1A , and so on. The compressed air device 30 is driven by a lifting and lowering device 71 and can move up and down in a vertical direction parallel to the axis AX. When the compressed air device 30 is raised, the paper container PC can be placed in the lower mold member 20. When the compressed air device 30 is lowered, the film material FM can be pressed against the inlet portion PCa formed at the upper portion of the paper container PC, thereby allowing the cutter 35 to cut the workpiece portion FLa from the film material FM. The heater 31 driven by the heater driver 72 can adjust the temperature to soften the workpiece portion FLa of the film material FM. The compressed air device 30 can use an air regulator 50 to reduce the pressure in the space facing the lower surface 30a of the compressed air device 30 through the vent 33, and can bring the workpiece portion FLa of the film material FM into close contact with the lower surface 30a. Therefore, the film material FM can be softened to a desired state while remaining in place. The lower surface 30a of the compressed air device 30 has a curved shape. This allows the workpiece portion FLa to be bonded to the lower surface 30a with wrinkles smoothed while being heated from the edge.The lower surface 30a is not limited to a curved shape and may be a flat shape.

[0083] The support member 40 temporarily secures the film material FM to the paper container PC by clamping it between itself and the film retaining member 23 of the lower mold member 20. The support member 40 is driven by a lifting and lowering device 73 and is movable up and down in a vertical direction parallel to the axis AX. When the support member 40 is raised, the film material FM can move horizontally on the paper container PC. When the support member 40 is lowered, the film material FM is clamped and secured between the upper surface 23a of the film retaining member 23 and the lower surface 40a of the support member 40.

[0084] The air regulator 50 is an air suction device and also functions as a compressed air blowing device. The air regulator 50 is connected to the vent 33 of the compressed air device 30. The air regulator 50 operates as an air suction device at a predetermined timing to suck the workpiece portion FLa of the film material FM onto the lower surface 30a of the compressed air device 30, thereby softening the workpiece portion FLa. The air regulator 50 operates as a compressed air blowing device at a predetermined timing to stretch the softened workpiece portion FLa by the compressed air introduced from the upper side, thereby deforming the workpiece portion FLa to be pressed against the inner surface IS of the paper container PC. The temperature of the compressed air supplied by the air regulator 50 through the vent 33 can be adjusted in temperature to maintain the degree of softening of the workpiece portion FLa of the film material FM.

[0085] The air suction unit 60 can draw a vacuum through the gap GA and the ventilation paths 28a and 28b to reduce the pressure in the cavity 21 of the lower mold member 20, and can reduce the pressure around the paper container PC placed on the lower mold member 20. This helps to bring the stretched workpiece portion FLa of the film material FM into close contact with the inner surface IS of the paper container PC during the compressed air blowing of the workpiece portion FLa of the film material FM.

[0086] The control device 80 controls the overall operation of the film bonding device 100. The control device 80 controls the temperature of the compressed air device 30 by controlling the driving state of the heater driver 72, and adjusts the height of the compressed air device 30 by controlling the driving state of the lifting and lowering device 71. The control device 80 adjusts the height of the support member 40 by controlling the driving state of the lifting and lowering device 73. By controlling the driving state of the air regulator 50, the control device 80 can adhere the workpiece portion FLa of the film material FM to the lower surface 30a of the compressed air device 30 at a desired timing, and can deform the softened workpiece portion FLa to be pressed against the inner surface IS of the paper container PC. At the same time, the control device 80 controls the driving state of the air suction unit 60 in synchronization with the air regulator 50, reduces the pressure around the paper container PC, and assists the operation of adhering the stretched workpiece portion FLa of the film material FM to the inner surface IS of the paper container PC.

[0087] Reference below Figure 6 7 illustrate a method for manufacturing the composite container 10. The apparatus for assembling the paper container PC is omitted in the figure.

[0088] Paper container assembly

[0089] First, if Figure 6As shown in , base paper 14 for paper container PC is prepared, and if necessary, a printed layer 15 is formed on the surface that will become the outer surface OS of paper container PC (step S11). A laminated finish may be applied to the outer surface OS after printing.

[0090] Subsequently, a binder HS is applied to predetermined positions on the surface of the main body member 11, which will become the inner surface IS of the paper container PC (binder applying step S12). The positions where the binder HS is applied are the portion corresponding to the side connecting portion 13a (side SD), the portion corresponding to the bottom connecting portion 13b (bottom BT), and the portion corresponding to the curled portion PCb at the top of the bottom plate member 12 (top TP). The binder HS is applied to the main body member 11 by printing or the like. The mark on the printed layer 15 is used as a reference for alignment when applying the binder HS. Before or after step S12, a laminated finish may be applied to the outer surface OS of the base paper 14.

[0091] Subsequently, the base paper 14 is cut into the main body member 11 and the bottom plate member 12, which are components (or blanks) of the paper container PC (step S13). The mark on the printed layer 15 is used as a reference when cutting the blanks.

[0092] Next, the main body member 11 and the bottom plate member 12 are joined together to form the paper container PC into a cup shape (joining step S14). The paper container PC is assembled using an assembly device (not shown). The main body member 11 and the bottom plate member 12 are joined together by heating the bonding agent HS. The heating temperature is equal to or higher than the melting point of the bonding agent HS, preferably within the range of 200°C to 500°C.

[0093] After the main body member 11 and the base member 12 are joined, a lubricant is applied to the upper portion (top TP) of the inner surface IS of the main body member 11 (lubricant application step S15). Since the binder HS has been previously applied to the upper portion of the main body member 11 in step S12, the lubricant does not easily penetrate the base paper 14, thereby facilitating the formation of the curled portion PCb in the subsequent process.

[0094] After the lubricant is applied, the upper portion of the paper container PC is rolled outward to form a curled portion PCb (curled portion forming step S16).

[0095] Film-to-paper container integration

[0096] The paper container PC assembled in steps S11 to S16 is placed in the film bonding device 100 (step S21). Specifically, the paper container PC is placed on the lower mold member 20 of the film bonding device 100. At this time, the control device 80 actuates the compressed air device 30 and the support member 40 to separate the compressed air device 30 and the support member 40 from the lower mold member 20.

[0097] Subsequently, the film material FM to be bonded to the inner surface IS of the paper container PC is supplied to the film bonding device 100 (step S22). Specifically, with the support member 40 raised, the control device 80 moves the film material FM in the horizontal direction above the paper container PC (see Figure 7A ).

[0098] Then, a workpiece portion FLa is cut from the film material FM according to the shape of the inlet portion PCa of the paper container PC (step S23). Specifically, the control device 80 lowers the support member 40 and secures the film material FM between the upper surface 23a of the film retaining member 23 and the lower surface 40a of the support member 40. The control device 80 further lowers the compressed air device 30 to pressurize the film material FM against the inlet portion PCa of the paper container PC and causes the cutter 35 to cut the workpiece portion FLa from the film material FM.

[0099] Subsequently, the workpiece portion FLa cut from the film material FM is attached to the compressed air device 30 of the film bonding device 100 to heat the workpiece portion FLa (film heating step S24). Specifically, the control device 80 operates the air conditioner 50 to draw air AR1 through the vent 33, thereby drawing the workpiece portion FLa onto the lower surface 30a of the compressed air device 30 (see FIG. Figure 7B ). In addition, the control device 80 operates the heater 31 to soften the workpiece portion FLa sucked into the compressed air device 30. The heating temperature of the heater 31 is equal to or higher than the melting point of the resin constituting the adhesive layer 16, preferably 160°C to 190°C.

[0100] Subsequently, while the paper container PC is being evacuated, the workpiece portion FLa of the film material FM is bonded to the inner surface IS of the paper container PC by compressed air forming (membrane bonding step S25). The workpiece portion FLa is sequentially adhered to the flange P1, the inner wall P2 of the main body, the bottom portion P3 and the V-zone VZ of the paper container PC. This makes it possible to ensure the thickness of the film FL while tightly adhering the film FL to the inner surface IS of the paper container PC without leaving air between the paper container PC and the film FL. It should be noted that the film FL does not adhere to the V-zone VZ. Although the film FL is not directly adhered to the inner surface IS of the paper container PC in the V-zone VZ, the film FL is very close to the inner surface IS without peeling off. Specifically, the control device 80 operates the compressed air device 30 to introduce compressed air AR2 from above the workpiece portion FLa through the vent 33, thereby stretching and deforming the softened workpiece portion FLa so that the softened workpiece portion FLa is pressed against the inner surface IS of the paper container PC (see Figure 7C ). In addition, the control device 80 operates the air suction unit 60 to perform vacuum suction, thereby passing through the gap GA (see Figure 5 ) and the vent paths 28a and 28b discharge air VA to reduce the pressure around the paper container PC, and cooperate with the compressed air flow generated by the compressed air device 30 to bond the workpiece portion FLa as a film FL to the inner surface IS of the paper container PC (see Figure 7C ). By shaping the heated film FL using a pressure difference, the formability of the film FL and the adhesion of the film FL to the paper container PC can be improved.

[0101] Finally, the composite container 10 having the film FL bonded to the paper container PC is ejected from the film bonding device 100 (step S26). Specifically, the control device 80 operates the compressed air device 30 and the support member 40 to raise the compressed air device 30 and the support member 40 and eject the composite container 10 from the lower mold member 20.

[0102] Although the film FL is bonded by using the pressure difference generated by both the introduction of compressed air (compressed air molding) and vacuum suction in the above, the film FL may be bonded by using the pressure difference generated by either compressed air molding or vacuum suction.

[0103] Implementation Example

[0104] Hereinafter, the assemblability of the paper container and the adhesion of the film to the paper container are described as an embodiment. 2The base paper 14 of the main body member 11 and the bottom plate member 12 is made of a basis weight of HC(E)COC (manufactured by O&I Voryboard Co., Ltd.). The outer surface OS of the main body member 11 is printed with OP varnish (overprint varnish). The air permeability coefficient (air permeability coefficient measured by the Oken method) of the base paper 14 with the OP varnish applied to the outer surface OS is 624 seconds. The binder HS used is, for example, CHEMIPEARL S500 (registered trademark, manufactured by Mitsui Chemicals, Inc.) as an ionomer. The amount of the binder HS applied is 9.4 g / m 2 .

[0105] (A) Assembling of paper containers

[0106] Figure 8A and Figure 8B The relationship between the bottom coating area of ​​the binder HS on the paper container PC and the assemblability of the paper container PC is shown. The bottom coating area is 9A to 9D The application area of ​​the bonding agent HS on the bottom BT is shown in FIG. Figure 9A The bottom coating area is shown as 0%. Figure 9B The bottom coating area is 26%. Figure 9C The bottom coating area is 90% and Figure 9D The case where the bottom coating area is 100% is shown. The bottom coating area is the total area of ​​one or more bottom application parts CC of the bottom BT, excluding the bottom non-application part NC1. In the embodiment, the number of bottom application parts CC is fixed to 20, and the bottom coating area is changed by adjusting the area of ​​each bottom application part CC. The bottom application parts CC have a uniform width or the same area and are arranged at regular intervals. When the bottom coating area is 0%, no bottom application part CC is provided, and the binder HS is not applied to the bottom BT (see Figure 9A ). When the bottom coating area is 100%, the entire bottom BT is used as the bottom application portion CC, and the bonding agent HS is applied to the entire bottom BT (see Figure 9D ).exist Figure 8A , the number of bottom application parts CC is defined as 20 for a 100% bottom coating area, assuming that there is no gap between the bottom application parts CC.

[0107] By making the bottom application portion CC have a uniform width or the same area, the bonding portions of the main body member 11 and the bottom plate member 12 are provided with uniform width or the same area at regular intervals. This allows air to be uniformly evacuated from the vents AP (i.e., the non-bonded portions NB), so that no stress is applied to any of the plurality of vents AP, making it less likely that the film FL will tear. Figure 8A The bottom coating gap BG shown in Figure 1B ) corresponds to Figure 1B The widest width of each non-bonded portion NB shown in FIG, which acts as an air VA (see Figure 7C ) through the entrance. Figure 8A As shown in FIG, the width of the bottom coating gap BG needs to be 4 mm or larger. This allows air to pass through the multiple vents AP (see FIG. Figure 2B ) is evacuated uniformly so that peeling of the film FL does not occur in the V zone VZ.

[0108] exist Figure 8A In the evaluation of the assemblability of the paper container PC, the symbol "√" indicates that the shape of the paper container PC is maintained and continuous assembly is achieved. When the bottom coating area is between 26% and 100%, good assemblability of the paper container PC is achieved. When the bottom coating area is 20% or less, the adhesion between the main body member 11 and the bottom plate member 12 is broken when the formed paper container PC is ejected, making continuous assembly difficult.

[0109] The adhesion of the bottom plate member 12 required for continuous assembly of the paper container PC was measured. The adhesion of the bottom plate member 12 was measured by a strength tester (specifically, a universal testing machine Strograph TM ) is measured as the strength at which the bottom plate member 12 begins to peel off when the bottom plate member 12 is compressed from the lower side or bottom edge of the bottom plate member 12 of the paper container PC. The diameter of the compression die of the strength testing machine is 106 mm, corresponding to the shape and size of the paper container PC, and the compression speed is 100 mm / min.

[0110] Figure 8B The adhesion of the base member 12 is shown. Figure 8B As shown in , it was found that an adhesion force of 52 N or greater was required to achieve continuous assembly of the paper container PC. When the adhesion force was 52 N or greater, paper delamination occurred in the paper container PC after the bottom plate member 12 was detached, indicating that the body member 11 and the bottom plate member 12 were sufficiently bonded to each other. It should be noted that when the bottom coating area is less than 20%, the adhesion of the bottom plate member 12 is weak, and the bottom plate member 12 may be detached.

[0111] (B) Adhesion of the film to the paper container

[0112] Figure 8AThe relationship between the formability of the film FL on a paper container PC and the tearing of the film FL is shown. The heating conditions used to bond the film FL or workpiece portion FLa to the paper container PC are a heating temperature of 177°C and a heating time of 1 second. The film FL is bonded to the inner surface IS of the paper container PC by compressed air forming at a compressed air pressure of 0.05 MPa to 0.15 MPa for an air compression time of 1.2 seconds, while simultaneously evacuating at a vacuum pressure of -56 kPa. When the film FL is successfully formed, the evaluation of formability is indicated by the symbol "√". In addition, the presence of lifting of the film FL in the V-zone VZ of the bottom connecting portion 13b formed by the main body member 11 and the bottom plate member 12 is checked, and when the lifting of the film FL is 3 mm or less, the evaluation is indicated by the symbol "√". Regarding the tearing of the film FL, the presence of tearing of the film FL is checked, and when no tearing is found, the evaluation is indicated by the symbol "√". It should be noted that tearing of the film FL may occur in the V-zone VZ.

[0113] like Figure 8A As shown in Figure 1 , the film FL exhibits good adhesion for bottom coating areas ranging from 26% to 80%. When the bottom coating area is 90%, partial lift occurs on the film FL in the V-zone VZ, while when the bottom coating area is 100%, lift occurs on the film FL over almost the entire periphery of the V-zone VZ. Tearing of the film FL can be addressed by adjusting the compressed air pressure, film type, and film thickness.

[0114] The composite container 10 and the method for manufacturing the composite container 10 described above make it possible to stabilize the adhesion between the paper container PC and the film FL because the base paper 14 is exposed at the adhesion surface BS between the paper container PC and the film FL, and the film FL includes the adhesive layer 16. Furthermore, the use of the binder HS in the side joints 13a and the bottom joint 13b, i.e., the joints required for assembling the paper container PC, makes it possible to reduce the amount of resin applied to the paper container PC while maintaining film adhesion across the entire inner surface IS of the paper container PC.

[0115] Although the present invention has been described above based on the embodiment, the present invention is not limited to the above-described embodiment, and various modifications are possible.

[0116] In the above embodiment, the film FL may be a single layer consisting solely of the adhesive layer 16. In other words, the base material layer 18 and the intermediate layer 17 may be omitted from the film FL. It should be noted that even when a single layer is used, it is not limited to being made of a single component material and may be a mixture of two or more types of resins, such as a combination of PP and PE. Furthermore, the film FL may be formed solely of the adhesive layer 16 and the base material layer 18, without the intermediate layer 17.

[0117] In the above embodiment, the bonding agent HS does not need to be applied to the entire surface of the side portion SD. In other words, the side application portion SS of the bonding agent HS may not be the entire surface of the side portion SD. Figures 10A to 10C As shown in FIG, a side non-applied portion NC2 of the bonding agent HS may exist on the side SD. The width of the side non-applied portion NC2 is greater than Figure 1B The bottom non-applying portion NC1 shown in FIG has a narrow width.

[0118] In the above embodiment, the position where the bonding agent HS is applied at the bottom connecting portion 13b may be modified as appropriate. Figure 11A As shown in , the bottom applying portion CC may be a region extending to a middle position of the bottom portion BT in the vertical direction of the body member 11 , rather than a region extending to the lowermost end portion of the bottom portion BT. Figure 11B and Figure 11C 13b of the assembled paper container PC. The connection state between the bottom portion 11b of the main body member 11 and the bottom plate member 12 changes depending on the application position of the bottom application portion CC.

[0119] Figure 11B An example of bonding between the bonding agent HS applied to the main body member 11 and the peripheral wall 12 b and the edge portion 12 d of the bottom plate member 12 is shown. Figure 11C FIG. 1 shows an example of bonding between the bonding agent HS applied to the main body member 11 and the peripheral wall 12b of the bottom plate member 12. The rear surface 12f of the bottom plate member 12 and the inner surface 11f of the main body member 11 are Figure 11B and Figure 11C 13b is not connected. Therefore, the inner wall 11bb of the main body part 11 is easily separated from the peripheral wall 12b of the bottom plate member 12 at the bottom connecting portion 13b. In this case, since the ventilation area along the inner wall 11bb is increased in the vent AP, vacuuming can be performed in a short time. This allows air to be discharged evenly through the vent AP, thereby reducing the film forming time and lowering the compressed air pressure. In addition, after heating the contents of the composite container 10 in a microwave oven, when the user holds the composite container 10 by hooking his or her fingers on the bottom portion 11b or the bottom edge, the inner wall 11bb separated from the bottom plate member 12 acts as a barrier to prevent the user's fingers from touching the bottom surface of the composite container 10, thereby preventing burns.

[0120] It should be noted that the position where the bonding agent HS is applied in the vertical direction can be divided in the bottom joint portion 13b. For example, the bottom application portion CC can be divided into an area between the upper end and the middle position of the bottom portion BT and an area on the lower end side in the vertical direction of the main body member 11. In this case, as shown in FIG. Figure 11Dand Figure 11E As shown in FIG, the outer wall 11ba of the main body member 11 and the peripheral wall 12b of the base member 12 are joined, and a portion of the inner wall 11bb of the main body member 11 is joined to a portion of the peripheral wall 12b of the base member 12 (in a cross-sectional view, an upper end portion or a middle portion of a rear surface 12f of the peripheral wall 12b). In this case, the bonding agent HS applied to the main body member 11 adheres to both sides of the peripheral wall 12b of the base member 12, making it less likely that the inner wall 11bb will separate from the peripheral wall 12b than when the bonding agent HS adheres to one side of the peripheral wall 12b.

[0121] In the above-described embodiment, the bonding agent HS may be applied to the outer periphery 12c of the bottom plate member 12 without applying the bonding agent HS to the body member 11. Figure 12A As shown in FIG, in an area corresponding to the bottom portion BT on the outer periphery 12 c of the bottom plate member 12 , a plurality of bottom applying portions CC are radially arranged. Figure 12B 13b of the bottom connecting portion 13b of the assembled paper container PC. Figure 12B The bottom connecting portion 13b shown in FIG is not connected.

[0122] In the above-described embodiment, the composite container 10 is not limited to a circular shape in a plane, but may have various polygonal or elliptical shapes.

[0123] In the above-described embodiment, while the film material FM is held between two additional heating plates (not shown) and is heated, the film material FM may be fed into the film bonding device 100, without limitation. Figure 7B , in which the workpiece portion FLa is heated after the film material FM is cut. Alternatively, a ceramic heater or the like may be used to heat the film material FM or the workpiece portion FLa using radiant heat from the heater. In this case, the heater 31 of the compressed air device 30 may be omitted as long as the softening of the film FL can be maintained.

[0124] Although the film FL is formed while being heated in the above-described embodiment, the film FL may be formed in a state in which the paper container PC is also heated.

[0125] Although the bottom plate member 12 is folded and attached to the bottom portion 11b of the main body member 11 in the above embodiment, Figure 13 As shown in FIG, the main body member 11 may be folded, and the bottom portion 11 b of the main body member 11 may be attached to the bottom plate member 12 without the bottom plate member 12 being folded.

[0126] In the above embodiment, the inlet portion PCa or the flange P1 of the composite container 10 does not need to be provided with the curled portion PCb. Figure 14A As shown in FIG, the flange end surface FF of the composite container 10 may be formed to face the horizontal direction. Figure 14B As shown in FIG, the flange end face FF of the composite container 10 can be formed to face upward. For this type of flange P1, the method of bonding the film FL can be appropriately modified in terms of the shape of the mold, or can be modified so that the film material FM is preheated by radiant heat and then vacuum pressure molded on the paper container PC serving as the lower mold in a state where the film area to be wound around the flange end face FF is fixed.

[0127] In the above embodiment, the curled portion PCb may also be formed after the film FL is bonded. Specifically, the paper container PC is first assembled without forming the curled portion PCb. Then, as shown in FIG. Figure 14B As shown in FIG, the flange end face FF of the composite container 10 is formed to face upward. The film FL or film material FM is preheated by radiant heat and then bonded to the paper container PC serving as the lower mold by vacuum pressure molding in a state where the film area to be wound around the flange end face FF is fixed. In this process, the base paper 14 of the paper container PC is not cut. Figure 14C As shown in FIG, after the film bonding, the film FL and the base paper 14 are rolled together to form a rolled portion PCb.

[0128] Although in the above embodiment, the vent AP in the bottom joint portion 13b is formed by the non-bonding portion NB corresponding to the bottom non-applied portion NC1 of the bonding agent HS defined for the body member 11, the vent AP may be formed by a different method. Figure 15 As shown in , the ventilation portion AP can be formed by providing a hole HL, a perforation, etc. slightly below the portion of the main body member 11 corresponding to the V zone VZ. In this case, as shown in Figure 9D As shown in FIG, the joining in the bottom joining portion 13b is achieved by applying bonding agent HS to the entire surface of the bottom portion BT of the body member 11. The application position of the bonding agent HS is adjusted so that the holes HL and the like are exposed, thereby allowing air to be discharged through the vent AP.

[0129] Obviously, the present invention is not limited to the above-mentioned embodiments, and these embodiments can be appropriately modified or changed within the scope of the technical concept of the present invention. The technology of each embodiment can be used in other embodiments as long as there is no technical inconsistency.

[0130] This application claims the benefit of Japanese Patent Application No. 2023-057757, filed on March 31, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A composite container comprising: A paper container comprising a main body member and a bottom plate member connected together; as well as a resin film bonded to the inner surface of the paper container, wherein the base paper of the paper container is exposed at the adhesion surface between the paper container and the film, wherein, regarding the paper container, the connection at the side connection portion connecting the side surface of the main body member and the connection at the bottom connection portion connecting the main body member and the bottom plate member are each achieved via a bonding agent, and wherein the film comprises an adhesive layer adhered to the base paper of the paper container.

2. The composite container according to claim 1, wherein A portion of the bottom connecting portion is provided with a vent portion that allows air to be discharged to the outside of the paper container.

3. The composite container according to claim 1 or 2, wherein The paper container includes a rolled portion in which a top portion of the main body member is rolled outward, and A bonding agent is provided on a portion of the inner surface of the paper container corresponding to the curled portion.

4. The composite container according to any one of claims 1 to 3, wherein The thickness of the film varies depending on the adhesion position to the paper container, and A portion of the film adhered to the bottom portion of the paper container is thicker than a portion of the film adhered to the inner wall of the main body of the paper container.

5. A method for manufacturing a composite container, the composite container comprising: A paper container comprising a main body member and a bottom plate member connected together; as well as a resin film bonded to the inner surface of the paper container, wherein the base paper of the paper container is exposed at the adhesion surface between the paper container and the film, and the film comprises an adhesive layer adhered to the base paper of the paper container, The method comprises: a bonding agent applying step of applying a bonding agent to portions of the inner surface of the paper container, the portions corresponding to side bonding portions bonding side surfaces of the body member together and a bottom bonding portion bonding the body member and a bottom plate member; a connecting step of completing the respective connections of the side connecting portions and the bottom connecting portion; and A film bonding step of bonding the film to the adhesive surface of the paper container using a pressure difference.

6. The manufacturing method according to claim 5, wherein: A portion of the bottom connecting portion is provided with a vent portion that allows air to be discharged to the outside of the paper container.

7. The manufacturing method according to claim 5 or 6, wherein: The paper container includes a rolled portion in which a top portion of the main body member is rolled outward, and wherein, during the bonding agent applying step, the bonding agent is applied to a portion of the inner surface of the paper container corresponding to the curled portion.

8. The manufacturing method according to any one of claims 5 to 7, further comprising a film heating step of heating the film, wherein during the film bonding step, the heated film is bonded to the adhesive surface of the paper container using the pressure difference.

9. The manufacturing method according to any one of claims 5 to 8, wherein The pressure difference is generated by introducing compressed air from above the membrane or by applying vacuum suction from below the paper container.

10. The manufacturing method according to any one of claims 5 to 9, wherein The film is sequentially adhered to the flange, the inner wall of the body, the bottom portion, and the V-region of the paper container.

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