Container manufacturing method, and container manufacturing device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2024-11-01
- Publication Date
- 2025-05-15
AI Technical Summary
Existing container manufacturing equipment is difficult to avoid membrane entanglement and safety hazards when cutting membranes, and the equipment structure is complex and requires regular maintenance.
By introducing a heatable protruding structure into the container manufacturing equipment, the membrane is melted and tightly attached to the inner wall of the container using heat, thereby reducing the amount of overflow of the membrane, simplifying the film processing process, and improving the safety of the container.
The tight fit and safe cutting of the film are achieved, the amount of spillage of the film is reduced, the equipment structure is simplified, the maintenance needs are reduced, and the safety of the container is improved.
Abstract
Description
Container manufacturing method and container manufacturing device
[0001] The present invention relates to a container manufacturing method and a container manufacturing apparatus for manufacturing a composite container.
[0002] Composite containers, which consist of a paper container with a film attached to the inner surface, are widely used. Composite containers are produced by placing a resin film over the opening of the container, heating the film to deform it due to a pressure difference, and then attaching the film to the inner surface of the container.
[0003] After the film is attached to the inner surface of the container, an annular cutter is used to cut off the film protruding from the outer periphery of the container, as shown in Japanese Patent Application No. 2023-57757. Specifically, as shown in Fig. 9, a conventional container manufacturing apparatus 100 includes a first molding die 200 that houses a container 110, and a second molding die 300 that is disposed opposite the first molding die 200 and heated by a heater. A cutting blade 301 for cutting the film FL is attached to the outer periphery of the second molding die 300.
[0004] In the conventional container manufacturing apparatus 100, the cutting blade 301 that cuts the film FL is attached to the outer periphery of the second molding die 300, so that a predetermined length of the film FL is cut in a state where it protrudes outward from the opening 111 of the container 110. This makes it more difficult to reel in the end of the cut film FL. Furthermore, if the end is not reeled in, there is a risk of injury to the mouth or hands of a person using the container 110.
[0005] The present invention has been made in consideration of the above-mentioned situation, and aims to provide a container manufacturing method and a container manufacturing apparatus that can reduce the amount of film protruding from the opening of a container by melt-cutting the film, making it easier to roll up the film and producing safe containers.
[0006] A container manufacturing method according to a first aspect of the present invention is a container manufacturing method for manufacturing a composite container by adhering a film to the inner surface of a container having a flange portion protruding outward from the peripheral portion of an opening, and includes the steps of: placing the container in a concave first mold; moving a second mold, which is positioned opposite the first mold and has a protrusion portion that is positioned on the outer periphery of the flange portion when the container is placed in the first mold, to the first mold; holding the film between the first mold and the second mold; adhering the held film to the inner surface of the container by an air pressure difference; and fusing the film with the protrusion portion.
[0007] The step of placing the container in the first mold may include a step of placing the flange portion on a mounting portion formed in the opening of the first mold, and the melt-cutting step may include melt-cutting the film outside the mounting portion by the inner surface of the protrusion.
[0008] The step of adhering the film to the inner surface of the container may include a step of heating the film.
[0009] The step of fusing may include the step of generating tension in the film on a side of the bottom of the first mold.
[0010] A container manufacturing apparatus according to a second aspect of the present invention is a container manufacturing apparatus that manufactures a composite container by adhering a film to the inner surface of a container that has a flange portion that protrudes outward from the peripheral portion of the opening, and comprises: a concave first mold that accommodates the container; a second mold that is arranged opposite the opening of the first mold and is equipped with a heater; and a film holding portion that is arranged on the outer periphery of the first mold and the second mold and holds the film that is inserted between the first mold and the second mold, wherein the first mold has a mounting portion on which the flange portion is placed; and the second mold has a protrusion that is formed on the side opposite the first mold and is arranged on the outer periphery of the mounting portion when the container is placed in the first mold, and the protrusion heated by the heater melts and cuts the film held by the film holding portion outside the mounting portion.
[0011] The inner surface of the protrusion may include an inclined wall that is inclined from the tip of the protrusion toward the placement portion, and the protrusion may fuse the film by bringing it into close contact with the inclined wall.
[0012] The container manufacturing apparatus may further include a tension generating unit that applies tension to the film held by the film holding unit toward the bottom of the container.
[0013] The tension generating section may generate tension in the film by moving the film holding section toward a bottom of the first mold.
[0014] The tension generating section may be a pressing member disposed between the first and second molding dies and the film holding section, and the pressing member may generate tension in the film by moving toward the bottom of the first molding die.
[0015] The container may be a cylindrical container.
[0016] According to the present invention, by melt-cutting the film, the amount of film protruding from the opening of the container can be reduced, making it easier to roll up the film and providing a container manufacturing method and container manufacturing apparatus that can produce safe containers.
[0017] 1A is a diagram showing a container used in an embodiment of the present invention, and is a diagram showing the appearance of the container. FIG. 1A is a diagram showing a container used in an embodiment of the present invention, and is a cross-sectional view taken along line A-A in FIG. 1A. FIG. 1B is a diagram showing a container used in an embodiment of the present invention, and is an enlarged view of the portion surrounded by the dotted line in FIG. 1B. FIG. 1C is a conceptual diagram of a container manufacturing apparatus according to this embodiment. (a) to (g) are conceptual diagrams showing steps of a container manufacturing method. (a) to (e) are conceptual diagrams showing main operations in steps of a container manufacturing method. FIG. 1D is a flowchart of a container manufacturing method. FIG. 1E is a diagram showing the relationship between fusion cutting and the amount of elongation of a film. FIG. 1F is a diagram showing the relationship between fusion cutting and the descending speed of a second mold. FIG. 1F is a diagram showing a modified example, showing a state in which a pressing unit is in contact with the film. FIG. 1F is a diagram showing a modified example, showing a state in which the film has been cut by the pressing unit. FIG. 1C is a conceptual diagram showing a conventional container manufacturing apparatus.
[0018] Hereinafter, embodiments of a container manufacturing apparatus and a container manufacturing method according to the present invention will be described with reference to the drawings. The embodiments described below are for illustrative purposes only and do not limit the scope of the present invention. Therefore, those skilled in the art may adopt embodiments in which each or all of the elements are replaced with equivalents, and these embodiments are also within the scope of the present invention.
[0019] (Embodiment) The structure of a container manufacturing apparatus according to one embodiment of the present invention will be described with reference to Figures 1A, 1B, 1C, and 2. In the figures, the side of the container manufacturing apparatus on which the second mold is disposed is defined as the upper side, and the side on which the first mold is disposed is defined as the lower side. These terms are used to describe this embodiment and do not limit the direction in which the embodiment of the present invention is actually used. Furthermore, these terms should not be used to limit the technical scope of the claims.
[0020] The container manufacturing apparatus and container manufacturing method described in this embodiment are a container manufacturing apparatus and container manufacturing method for manufacturing a composite container by adhering a sheet-like film made of resin to the inner surface of a paper container.
[0021] (Containers used in the container manufacturing apparatus) The paper containers used in this embodiment will be described with reference to Fig. 1. Fig. 1A is a diagram showing the appearance of the paper container, Fig. 1B is a cross-sectional view taken along line A-A in Fig. 1A, and Fig. 1C is an enlarged view of the portion surrounded by the dotted line in Fig. 1B.
[0022] As shown in Figures 1A and 1B, the container 10 is a cylindrical paper container that is used to store beverages such as juice or coffee, or foods such as pasta, gratin, or beef bowls. The container 10 includes a body 11 and a bottom 12. The cross-sectional shape of the body 11 tapers toward the bottom. The body 11 is formed by forming a sheet-like blank cut from base paper into a cylindrical shape and bonding both ends of the blank together. The bonded portion forms a seam 13. The bottom 12 is a plate-like member that closes the lower opening of the body 11.
[0023] The upper opening of the body 11 has a curled portion 11a formed by rolling its peripheral edge outward. The curled portion 11a is a flange portion that protrudes outward from the upper opening of the body 11 and is formed in a circular ring shape in a top view. The lower end of the body 11 is folded inward to form a folded portion 11b. The bottom 12 has a peripheral wall 12a whose outer periphery is folded downward. As shown in FIGS. 1B and 1C , the peripheral wall 12a of the bottom 12 is inserted into a space formed by folding back the folded portion 11b of the body 11, thereby closing the lower opening of the body 11 with the bottom 12. The folded portion 11b and the peripheral wall 12a are bonded together with an adhesive material, but the entire surfaces of the folded portion 11b and the peripheral wall 12a are not bonded together; rather, there are bonded regions (bonded regions) and non-bonded regions (non-bonded regions). The non-adhesive space formed by the non-adhesive region is used to exhaust air trapped between the film FL and the inner surface of the container 10 when the film FL is tightly attached to the inner surface of the container 10.
[0024] (Container Manufacturing Apparatus) The container manufacturing apparatus is an apparatus that manufactures composite containers by closely adhering a resin film to the inner surface of a paper container 10, and its overall configuration is shown in Fig. 2. The container manufacturing apparatus 1 includes a first forming mold 20, a second forming mold 30, a film holding unit 40, a heater control unit 50, an air control unit 60, an elevation drive unit 70, an exhaust unit 80, and a control device 90.
[0025] The first molding die 20 is a molding die having a recess into which the container 10 is inserted. The first molding die 20 has a cylindrical cavity 21 and a disk-shaped pedestal 22 installed at the bottom of the cavity 21. An annular first film holding member 41 is arranged on the outer periphery of the first molding die 20. A spring 24, which is an elastic member, is connected to the bottom of the first film holding member 41. The cavity 21, pedestal 22, and spring 24 are positioned and fixed on a base 23.
[0026] The cavity 21 has a diameter that decreases from the top to the bottom and has a shape that can accommodate the body 11 of the container 10. A mounting portion 21a is formed at the upper end of the cavity 21 on which the curled portion 11a of the container 10 is placed. The mounting portion 21a has a width and shape that are sufficient to mount the curled portion 11a, which has a circular shape in top view.
[0027] The pedestal 22 has a flat surface on its upper surface on which the bottom 12 of the container 10 is placed, and together with the cavity 21, forms the first molding die 20 that receives the container 10. A gap G is formed between the upper outer periphery of the pedestal 22 and the cavity 21, and the folded portion 11b and peripheral wall 12a of the container 10 are inserted into this gap G. Air passages 25 for passing air are formed between the inner periphery of the cavity 21 and the outer periphery of the pedestal 22, and between the bottom of the pedestal 22 and the base 23. An air passage 26 communicating with the air passage 25 is formed in the base 23 and connected to an exhaust unit 80, which will be described later. Air between the inner periphery of the cavity 21 and the outer periphery of the pedestal 22, and air between the bottom of the pedestal 22 and the base 23, is sucked by the exhaust unit 80 and exhausted to the outside via the air passages 25, 26. In addition, the air trapped between the inner surface of the container 10 and the film FL during the process of adhering the film FL to the inner surface of the container 10 is also discharged to the outside by the exhaust section 80 through the non-adhesive space of the container 10 and the ventilation paths 25, 26.
[0028] The annular first film holding member 41 has a flat upper surface and is a member that holds the film FL by sandwiching it between itself and the second film holding member 42, which will be described later. When force is applied from above to the first film holding member 41, the spring 24 attached to the lower part contracts, causing the first film holding member 41 to move downward. In this embodiment, the spring 24 is used, but the expandable member is not limited to the spring 24, and other members such as a pneumatic cylinder that expands and contracts using air pressure may also be used.
[0029] The film FL used in this embodiment generally has a three-layer structure. That is, the film FL has, in order from the adhesive surface side of the base paper, an adhesive layer, an intermediate layer, and a substrate layer that supports the adhesive layer and the intermediate layer. The substrate layer is a layer that has water resistance and chemical resistance, and can be made of, for example, polypropylene (PP) or polyethylene (PE). The intermediate layer is a layer that mainly suppresses the formation of pinholes, and can be made of a laminate of nylon (Ny) and ethylene vinyl alcohol resin (EVOH), or a laminate of ionomer and EVOH. The adhesive layer is a layer that adheres to the base paper of the paper container, and can be made of polyolefins such as PP or PE, or modified resins thereof.
[0030] The second molding die 30 is disposed opposite the opening of the first molding die 20 and includes a mold body 31 and a heater portion 32 .
[0031] The lower surface of the mold body 31 has a curved surface 31a that curves upward, and when air is sucked by the air control unit 60 (described later), the film FL is sucked onto the curved surface 31a.
[0032] A plurality of air vents 35 are formed in the curved surface 31a of the mold body 31, and air is sucked in or blown out through the plurality of air vents 35 by an air control unit 60. The plurality of air vents 35 are collectively connected to an air vent 36 formed in the heater unit 32 arranged above the mold body 31. The air vent 36 is connected to the air control unit 60. When air is sucked in through the air vents 35, the film FL held by the first film holding member 41 and the second film holding member 42 is adsorbed to the curved surface 31a. When compressed air is blown out through the air vents 35, the film FL adsorbed to the curved surface 31a is separated from the curved surface 31a and molded inside the first molding die 20.
[0033] A downwardly protruding annular protrusion 34 is formed on the outer periphery of the lower part of the mold body 31. The inner surface of the protrusion 34 has an inclined wall 34a that is inclined from the tip of the protrusion 34 toward the mounting portion 21a. The inclined wall 34a and the mounting portion 21a sandwich the curled portion 11a and the film FL, bringing the curled portion 11a and the film FL into close contact with each other.
[0034] The heater section 32 is disposed above the mold body 31 and incorporates a plurality of rod-shaped heaters 33. The heater section 32 is formed as a rectangular parallelepiped block, and the plurality of rod-shaped heaters 33 are disposed in parallel within the block. The heaters 33 heat the mold body 31, the heated protrusions 34 melt-cut the film FL, and the heated curved surface 31 a softens the film FL adsorbed to the curved surface 31 a.
[0035] The heater section 32 is formed with an air vent 36 that penetrates in the vertical direction. The air vent 36 includes a suction air vent 36a and a blow-out air vent 36b, and the air control section 60, which will be described later, uses the suction air vent 36a as a vacuum path when vacuuming, and the blow-out air vent 36b as a compressed air path when pressure molding.
[0036] An annular second film holding member 42 is disposed on the outer periphery of the second molding die 30. The second film holding member 42 is disposed opposite the first film holding member 41, and as the second film holding member 42 descends, it comes into contact with the first film holding member 41 and holds the film FL between itself and the first film holding member 41. The first film holding member 41 and the second film holding member 42 constitute the film holding section 40.
[0037] The film holding portion 40 is not heated by the heater 33, and the film FL held by the film holding portion 40 is kept at a low temperature. Because the protrusions 34 are overheated and the film holding portion 40 is not heated, this temperature difference allows the film FL to be easily melted by the protrusions 34.
[0038] The second film holding member 42 and the second molding die 30 are connected at the top of the container manufacturing apparatus 1 via a connecting member 43 connected to the top of the second film holding member 42 and an air cylinder 71 connected to the top of the second molding die 30, and move together.
[0039] The heater control unit 50 controls the on / off and temperature of the heater 33. The heater control unit 50 sets the heating temperature of the heater 33 according to the melting temperature of the film to be melted by the protrusions 34. The melting point of the film differs depending on the main resin material used in the film, and is 160°C or higher for polypropylene (PP)-based films and 130°C or higher for polyethylene (PE)-based films.
[0040] The air control unit 60 is a device that switches between sucking air through the air vents 35 of the second molding die 30 and blowing compressed air. For example, a vacuum pump is used to suck air, and an air compressor is used to blow compressed air. When adsorbing the film FL onto the curved surface 31a, the vacuum pump sucks air through the suction vents 36a, and when pressure-forming the film FL, the air compressor blows compressed air from the curved surface 31a through the blow-out vents 36b. The air control unit 60 performs suction and blow-out by switching between the operation of the vacuum pump and the air compressor.
[0041] The lifting / lowering drive unit 70 is a device that raises and lowers the second forming die 30 and the second film holding member 42 as a unit. For example, a servo press is used as the lifting / lowering drive unit 70. A servo press is a device that raises and lowers the second forming die 30 and the second film holding member 42 by driving a servo motor. As the lifting / lowering drive unit 70, not only mechanical presses such as servo presses but also various other presses such as hydraulic presses can be used. Furthermore, in the process of pressing the curled portion 11a of the container 10 described below, the air cylinder 71 alone can be lowered separately to press the curled portion 11a.
[0042] When the second film holding member 42 is lowered by the lifting drive unit 70, the second film holding member 42 comes into contact with the first film holding member 41 and holds the film FL by sandwiching it. The second film holding member 42 continues to descend after coming into contact with the film FL, and as it descends, the spring 24 provided below the first film holding member 41 is compressed, and the film FL sandwiched by the holding unit 40 is pulled downward. The first film holding member 41, the second film holding member 42, and the spring 24 function as a tension generating unit that generates tension in the film FL in a diagonally downward direction.
[0043] The exhaust unit 80 exhausts the air between the inner periphery of the cavity 21 and the outer periphery of the pedestal 22, the air between the lower surface of the pedestal 22 and the base 23, and the air between the inner surface of the container 10 and the film FL via the air passages 25 and 26, thereby bringing the film FL into close contact with the inner surface of the first molding die 20. As the exhaust unit 80, for example, a vacuum pump is used.
[0044] The control device 90 is a device that controls the overall operation of the container manufacturing apparatus 1. Depending on the material of the film FL being used, the control device 90 controls the temperature of the heater 33 by the heater control unit 50, controls the suction and blowing of air from the second mold 30 by the air control unit 60, controls the lifting speed of the lifting drive unit 70, and controls the exhaust of the exhaust unit 80. The control device 90 has a built-in CPU, which executes programs for control.
[0045] (Container Manufacturing Method) A method for manufacturing a composite container by tightly adhering a film FL to a paper container 10 will be described with reference to FIGS.
[0046] First, the control device 90 instructs an insertion device (not shown) to place the container 10 in the recess of the first molding die 20 (step S101). The curled portion 11a of the container 10 is placed on the placement portion 21a of the first molding die 20 (step of placing the container in the first molding die 20).
[0047] Next, the control device 90 instructs the film insertion device (not shown) to insert the film FL between the first mold 20 and the second mold 30 ( FIG. 3A ) (step S102). The control device 90 then instructs the lifting / lowering drive unit 70 to start lowering the second mold 30 (step S103). As the second mold 30 descends, the first film holding member 41 and the second film holding member 42 come into contact, thereby holding the film FL ( FIG. 3B ) (step S104) (film holding process). At this time, the held film FL is held linearly, and this position is designated as the initial position. The length from the top surface of the base 23 to the top end of the spring 24 is 75 mm (hereinafter referred to as the "spring length"). The control device 90 also instructs the air control unit 60 to start suctioning air through the air vent 35. The suction of air by the air control unit 60 continues from when the film FL is held until the film FL is separated from the second molding die 30 .
[0048] As the second mold 30 moves further downward, the first and second film holding members 41 and 42 holding the film FL also move downward, and the held film FL is pulled diagonally downward, moving downward by 1 mm from its initial position (FIG. 3(c) and FIG. 4(a)). At this time, the spring 24 installed below the first film holding member 41 contracts downward, and the length of the spring becomes 74 mm.
[0049] As the first film holding member 41 and the second film holding member 42 move further downward, the held film FL is pulled downward by 2 mm from its initial position, and the inner inclined wall 34a of the protrusion 34 of the second mold 30 comes into contact with the film FL (FIG. 3(d) and FIG. 4(b)). The contact portion between the inclined wall 34a and the film FL is indicated by a dotted circle. The spring 24 contracts to 73 mm.
[0050] Furthermore, when the first film holding member 41 and the second film holding member 42 are lowered and the held film FL is pulled downward by 5 mm from its initial position, the film FL is sandwiched between the inner inclined wall 34a of the protrusion 34 of the second mold 30 and the curled portion 11a of the container 10, sealing the inside of the curled portion 11a (see FIGS. 3(e) and 4(c)). At this time, air is sucked in through the vent hole 35 by the air control unit 60, so that the film FL is adsorbed to the curved surface 31a of the second mold 30. At the same time, the curved surface 31a is heated by the heater 33, so that the film FL is softened (step S105). The spring 24 contracts to 70 mm.
[0051] Furthermore, the first film holding member 41 and the second film holding member 42 are lowered, and the held film FL is lowered 7 mm from its initial position and pulled downward. When the second molding die 30 presses the curled portion 11a by the air cylinder 71, the curled portion 11a is crushed and flange pressing is performed (FIG. 3(f) and FIG. 4(d)) (step S106). The flange pressing seals the inside of the container 10 and prevents air leakage from the curled portion 11a due to deformation of the curled portion 11a during pressure forming. The spring 24 contracts to 68 mm.
[0052] Furthermore, when the first film holding member 41 and the second film holding member 42 are lowered and the held film FL is lowered 8 mm from its initial position, the film FL is melted by the protrusions 34 heated by the heater 33 (see (g) of FIG. 3 and (e) of FIG. 4) (step S107) (film melting process). Since the film FL is melted by the inner corners (part of the inclined walls 34a) at the tips of the protrusions 34, the film FL is melted near the mounting section 21a, and the length by which the film FL protrudes from the mounting section 21a can be shortened. The spring 24 contracts to 67 mm.
[0053] The control device 90 instructs the air control unit 60 to blow compressed air from the multiple air vents 35 of the second mold 30 simultaneously with the fusing operation. The softened film FL expands inside the first mold 20 due to the compressed air, and is subjected to pressure forming. The control device 90 also instructs the exhaust unit 80 to exhaust the air trapped between the inner surface of the container 10 and the film FL through the non-adhesive space between the body 11 and bottom 12 of the container 10 and the air vents 25, 26. The exhaust brings the container 10 and the film FL into close contact, and vacuum forming is performed to produce a composite container (step S107) (a process of adhering the film FL to the inner surface of the container).
[0054] When molding is complete, the control device 90 instructs the lifting drive unit 70 to raise the second molding die 30 and the first film holding member 42, and the manufactured composite container is removed from the first molding die 20 (step S108).
[0055] (Example) It was verified that satisfying several conditions is more effective for melt-cutting the film. The conditions include the temperature of the protrusion 34 of the second molding die 30, the amount of elongation of the film FL that occurs when the first film holding member 41 and the second film holding member 42 descend, and the descending speed of the first film holding member 41 and the second film holding member 42. Of these conditions, the optimal conditions were verified through experiments.
[0056] <Relationship between temperature of protrusion and fusing> Table 1 shows the heating temperature of the protrusion 34 and whether or not the film FL breaks. The film used in this example had a thickness of 105 μm, and the film structure, from the inner surface of the container 10 toward the paper side, was PE / AD / EVOH / AD / PE-based adhesive resin. The weight percentages (wt%) of each layer, from the inner surface of the container 10 toward the paper side, were 43 / 3.5 / 7 / 3.5 / 43, respectively, and the film was based on a PE-based resin.
[0057]
[0058] As shown in Table 1, the film FL was not melt-cut at room temperatures of 25° C. and 70° C., but was about 30% melt-cut at 100° C., 90% melt-cut at 120° C., and completely melt-cut at 130° C. and 135° C. Thus, it was confirmed that melt-cutting was possible if the temperature of the protrusions 34 was equal to or higher than 130° C., which is the melting point of the PE-based material that is the base material of the film FL.
[0059] The film FL can be cut by setting the temperature at or above the melting point of the base resin material. In this example, a PE-based resin material was used, but for a film FL based on a PP-based resin material, for example, a temperature of 160°C or above the melting point must be set. The temperature of the protrusions 34 may be set depending on the type of base resin material.
[0060] <Relationship with elongation amount of film> Table 2 shows the relationship between the temperature of the protrusion 34 of the second molding die 30 and the elongation amount of the film FL. The elongation amount of the film FL is defined as the distance from the apex of the curled portion 11a of the container 10 to the held end of the film FL held by the first film holding member 41 and the second film holding member 42, as shown in Figure 6.
[0061]
[0062] As shown in Table 2, even if the heating temperature of the protrusions 34 is equal to or higher than the melting point of the base resin material, if the elongation of the film FL is 0.5 mm or less and the tensile strength is 5.4 MPa or less, the film will not melt-cut, and it has been confirmed that it is preferable to apply tension to the film FL with a force that elongates the film FL by 0.8 mm or more and has a tensile strength of 9.2 MPa or more. Here, the tensile strength is a value derived from the results of the JIS 7113 tensile strength test for a film alone.
[0063] <Relationship with Descending Speed of Second Mold> Table 3 shows the relationship between the temperature and the descending speed of the second mold 30. As shown in Fig. 7, the conditions under which the heated second mold 30 can be melted were examined by changing the speed at which the heated second mold 30 descends in the direction of the arrow.
[0064]
[0065] As shown in Table 3, it was demonstrated that a high fusing effect is achieved when the temperature of the protrusion 34 of the second molding die 30 is equal to or higher than the melting point of the main resin material of the film FL used, and when tension is applied to the film FL with a force such that the film FL elongates by 0.8 mm or more and has a tensile strength of 9.2 MPa or more, and when the second molding die 30 is lowered at a speed of 100 mm / sec or more.
[0066] In the present embodiment, the first film holding member 41 and the second film holding member 42 move downward while sandwiching the film FL, thereby applying downward tension to the film FL and fusing it. However, the first film holding member 41 and the second film holding member 42 may not move, and a separate member may apply downward tension to the film FL.
[0067] As shown in Figure 8, this modified example is characterized in that a pressing member 400 is arranged between the first molding die 20 and the second molding die 30 and the first film holding member 41 and the second film holding member 42.
[0068] As shown in Figure 8A, after the curled portion 11a of the container 10 is pressed flat by the second molding die 30, the pressing member 400 descends and applies downward tension to the film FL, causing the film FL to be melt-cut as shown in Figure 8B.
[0069] The pressing member 400 is disposed near the protrusion 34 of the second molding die 30, and therefore can melt-cut the film FL near the curled portion 11a of the container 10. Therefore, the length of the film FL protruding outward from the curled portion 11a of the container 10 can be shortened.
[0070] In this way, according to this embodiment, the film FL is fused using the heated protrusion 34 without using a cutting blade, so that the container manufacturing apparatus 1 can be designed compactly and maintenance such as replacing the cutting blade is not required.
[0071] According to this embodiment, the curled portion 11a of the container 10 and the film FL are sandwiched between the inclined wall 34a of the protrusion 34 and the mounting portion 21a, and the film FL is then fused, so that the film FL can be fused at a position close to the curled portion 11a. This makes it easy to roll up the outer periphery of the fused film FL and prevents injury to the user's mouth.
[0072] According to this embodiment, the inner surface of the protrusion 34 is formed as an inclined wall 34a, so that the molten film FL does not stick to the protrusion 34 and can be smoothly cut by fusing.
[0073] According to this embodiment, the operation of adsorbing the film FL to the curved surface 31a to soften the film FL and the operation of clamping the curled portion 11a and the film FL between the mounting portion 21a and the protrusion portion 34 are performed simultaneously, so that the inner space between the mounting portion 21a and the protrusion portion 34 is sealed and the film FL can be evenly adhered to the inner surface of the container 10.
[0074] According to this embodiment, the film FL is fused while tension is being generated on the bottom side of the first molding die 20, so that the film FL can be easily cut.
[0075] According to this embodiment, the container 10 is cylindrical, and the film FL can be easily fused together with the annular protrusion 34 .
[0076] In the present embodiment, the container 10 is described as a cylindrical paper container, but the shape is not limited to a cylindrical shape. For example, the container may be a box-shaped container that is rectangular when viewed from above. When a box-shaped container is used, unlike the cylindrical container 10, the flange portion is formed by a flat piece of paper that protrudes outward from the opening of the box, rather than the curled portion 11a.
[0077] In the present embodiment, the second molding die 30 and the second film holding member 42 are described as being integral, but they may be separate bodies. By providing them as separate bodies, the tension applied to the film FL can be precisely controlled.
[0078] In this embodiment, it has been described that the second molding die 30 descends and comes into contact with the first molding die 20, but the first molding die 20 and the second molding die 30 may simply move relative to each other and approach each other, or the first molding die 20 may rise.
[0079] In the present embodiment, the heater 33 of the heater unit 32 is described as heating the protrusions 34 and the curved surface 31 a. The heater 33 may be controlled separately as a heater for heating the protrusions 34 and a heater for heating the curved surface 31 a. By using separate heaters, the temperatures of the protrusions 34 and the curved surface 31 a can be controlled separately, allowing for more precise temperature control. The heater 33 may also be built into the mold body 31.
[0080] In the present embodiment, the heater 33 is described as being made up of multiple rod-shaped heaters arranged in parallel, but a heater having an annular shape when viewed from above may also be used. Also, a cooling device may be attached to the second molding die 30 to perform temperature control.
[0081] In this embodiment, the inner surface of the protrusion 34 is described as having the inclined wall 34a, but the inner surface of the protrusion 34 may be shaped to extend straight without being inclined.
[0082] In this embodiment, the composite container is manufactured using both pressure forming and vacuum forming to form the composite container, but it may be manufactured using either pressure forming or vacuum forming alone.
[0083] In this embodiment, the held film FL is pulled diagonally downward to be fused, but the pulling direction may be diagonally upward. In that case, the film holding part 40 is raised, and the film FL is fused at the outer corner of the tip of the protrusion 34. In order to shorten the length of the film FL, the pulling direction is preferably diagonally downward.
[0084] This application is based on Japanese Patent Application No. 2023-189854, filed on November 7, 2023. The entire specification, claims, and drawings of Japanese Patent Application No. 2023-189854 are incorporated herein by reference.
[0085] The present invention can be used in a container manufacturing method and a container manufacturing apparatus for manufacturing a composite container.
[0086] DESCRIPTION OF SYMBOLS 1 Container manufacturing apparatus 10 Container 11 Body 11a Curled portion 11b Folded portion 12 Bottom 12a Peripheral wall 13 Seam portion 20 First molding die 21 Cavity 21a Placement portion 22 Pedestal 23 Base 24 Spring 25, 26 Air passage 30 Second molding die 31 Mold body 31a Curved surface 32 Heater portion 33 Heater 34 Protrusion portion 34a Inclined wall 35, 36 Air vent 36a Suction vent 36b Blowout vent 40 Film holding portion 41 First film holding member 42 Second film holding member 43 Connecting member 50 Heater control unit 60 Air control unit 70 Lifting drive unit 71 Air cylinder 80 Exhaust unit 90 Control device 100 Container manufacturing device 110 Container 200 First forming die 300 Second forming die 301 Cutting blade 400 Pressing member
Claims
1. A container manufacturing method for manufacturing a composite container by adhering a film to the inner surface of a container which has a flange protruding outward from the periphery of an opening, comprising the steps of: placing the container in a concave first mold; moving, to the first mold, a second mold which is disposed opposite the first mold and has a protrusion which will be positioned on the outer periphery of the flange when the container is placed in the first mold; holding a film between the first mold and the second mold; adhering the held film to the inner surface of the container by an air pressure difference; and melting the film by the protrusion.
2. A container manufacturing method as described in claim 1, wherein the step of placing the container in the first mold includes a step of placing the flange portion on a mounting portion formed in the opening of the first mold, and in the melt-cutting step, the film is melt-cut outside the mounting portion by the inner surface of the protrusion.
3. The method for manufacturing a container according to claim 2, wherein the step of adhering the film to the inner surface of the container includes a step of heating the film.
4. The method for manufacturing a container according to claim 1, wherein the melt-cutting step includes a step of generating tension in the film on the bottom side of the first mold.
5. A container manufacturing apparatus for manufacturing a composite container by adhering a film to the inner surface of a container having a flange portion protruding outward from the peripheral portion of an opening, comprising: a concave first molding die for accommodating the container; a second molding die arranged opposite the opening of the first molding die and equipped with a heater; and a film holding portion arranged on the outer periphery of the first molding die and the second molding die and holding the film inserted between the first molding die and the second molding die; wherein the first molding die has a mounting portion for placing the flange portion, and the second molding die has a protrusion formed on the side opposite the first molding die and equipped with a protrusion that is arranged on the outer periphery of the mounting portion when the container is accommodated in the first molding die, and the protrusion heated by the heater melts and cuts the film held by the film holding portion outside the mounting portion.
6. The container manufacturing device according to claim 5, wherein the inner surface of the protrusion has an inclined wall that inclines from the tip of the protrusion toward the placement portion, and the protrusion melts the film by adhering it to the inclined wall.
7. The container manufacturing apparatus according to claim 5, further comprising a tension generating section which applies tension to the film held by the film holding section towards the bottom of the container.
8. The container manufacturing apparatus according to claim 7, wherein the tension generating section generates tension in the film by the film holding section moving toward the bottom of the first mold.
9. The container manufacturing apparatus according to claim 7, wherein the tension generating section is a pressing member disposed between the first and second forming dies and the film holding section, and the pressing member generates tension in the film by moving toward the bottom side of the first forming die.
10. The container manufacturing apparatus according to claim 5, wherein the container is a cylindrical container.