Container manufacturing method and container manufacturing apparatus

Abstract

The container manufacturing method is a method for manufacturing a composite container by making a film (FL) tightly adhered to the inner surface of a container (10) having a flange portion protruding outward from the periphery of the opening. The method includes the following steps: a step of receiving the container (10) in a concave first forming mold (20); a step of moving a second forming mold (30) to the first forming mold (20), the second forming mold (30) being configured to face the first forming mold (20) and having a protrusion (34) disposed on the outer periphery of the flange portion when the container (10) is received in the first forming mold (20); a step of holding the film (FL) between the first forming mold (20) and the second forming mold (30); a step of making the held film (FL) tightly adhered to the inner surface of the container (10) by means of a pressure difference; and a step of melting the film (FL) by means of the protrusion (34).

Description

Technical Field

[0001] This invention relates to a container manufacturing method and a container manufacturing apparatus for manufacturing composite containers. Background Technology

[0002] Composite containers, in which a thin film is adhered to the inner surface of a paper container, are now widely used. The process involves placing a resinous film at the container opening, heating the film and deforming it using a pressure difference, and then adhering the film to the inner surface of the container.

[0003] After the film is adhered to the inner surface of the container, as shown in Japanese Patent Application No. 2023-57757, the film protruding from the outer periphery of the container is cut off using a ring-shaped cutter. Specifically, as... Figure 9 As shown, the existing container manufacturing apparatus 100 includes: a first forming mold 200 for receiving a container 110, and a second forming mold 300 configured to face the first forming mold 200 and heated by a heater. A cutting blade 301 for cutting the film FL is mounted on the outer periphery of the second forming mold 300.

[0004] In the existing container manufacturing apparatus 100, the cutting blade 301 for cutting the film FL is mounted on the outer periphery of the second forming mold 300, so the film FL of a predetermined length is cut in a state where it flies outward from the opening 111 of the container 110. Therefore, it becomes more difficult to wind up the end of the cut film FL. In addition, if it is not wound up, it may injure the mouth or hands of the person using the container 110. Summary of the Invention

[0005] The present invention was made in view of the above-mentioned actual situation, and its object is to provide a container manufacturing method and container manufacturing apparatus that reduces the amount of film protruding from the opening of the container by melting the film, makes the film winding operation easy, and enables the manufacture of safe containers.

[0006] The first aspect of the present invention relates to a container manufacturing method that manufactures a composite container by bonding a thin film to the inner surface of a container having a flange portion protruding outward from the periphery of an opening, wherein the method includes the following steps:

[0007] The process of housing the above-mentioned container in a concave first forming mold;

[0008] The process of moving the second forming mold to the first forming mold, wherein the second forming mold is configured to face the first forming mold and has a protrusion disposed on the outer periphery of the flange portion when the container is received in the first forming mold;

[0009] The process of holding the film between the first forming mold and the second forming mold;

[0010] The process of using air pressure difference to ensure that the aforementioned film is tightly adhered to the inner surface of the container; and

[0011] The process of melting the aforementioned film using the protrusions.

[0012] Alternatively, the process of housing the container in the first molding die may include the process of placing the flange portion on a mounting portion formed in the opening of the first molding die.

[0013] In the above-mentioned melting process, the film is melted off on the outside of the mounting portion by the inner surface of the protrusion.

[0014] Alternatively, the process of adhering closely to the inner surface of the container may include the process of heating the film.

[0015] Alternatively, the melting process may include a process of generating tension on the bottom side of the first forming mold of the thin film.

[0016] The second aspect of the present invention relates to a container manufacturing apparatus that manufactures a composite container by adhering a thin film to the inner surface of a container having a flange portion protruding outward from the periphery of an opening, wherein the apparatus comprises:

[0017] A concave first forming mold accommodates the aforementioned container;

[0018] The second forming mold, configured to face the opening of the first forming mold, includes a heater; and

[0019] A film holding portion is disposed on the outer periphery of the first forming mold and the second forming mold to hold the film inserted between the first forming mold and the second forming mold.

[0020] The first forming mold described above includes a mounting portion for mounting the flange portion.

[0021] The second forming mold has a protrusion formed on a side opposite to the first forming mold, and is positioned on the outer periphery of the mounting portion when the container is housed in the first forming mold.

[0022] After being heated by the heater, the protrusion will melt the film held by the film holding part on the outside of the mounting part.

[0023] Alternatively, the inner surface of the protrusion may have an inclined wall that slopes from the front end of the protrusion toward the mounting portion.

[0024] The protrusions cause the film to adhere tightly to the inclined wall, thereby achieving melting.

[0025] Alternatively, the container manufacturing apparatus may further include a tension generating section that applies tension to the bottom side of the container by means of the film held by the film holding section.

[0026] Alternatively, the tension generating part can move towards the bottom side of the first forming mold via the film holding part to generate tension in the film.

[0027] Alternatively, the tension generating part can be an extrusion component disposed between the first forming die and the second forming die and the film holding part.

[0028] The extrusion component moves toward the bottom side of the first forming die, thereby generating tension in the film.

[0029] Alternatively, the container described above could be a cylindrical container.

[0030] According to the present invention, a container manufacturing method and container manufacturing apparatus are provided that reduce the amount of film protruding from the opening of the container by melting the film, facilitate the film winding operation, and enable the manufacture of safe containers. Attached Figure Description

[0031] Figure 1A This is a diagram showing the container used in an embodiment of the present invention, and it shows the appearance of the container.

[0032] Figure 1B This is a diagram illustrating the container used in an embodiment of the present invention. Figure 1A A cross-sectional view at line AA.

[0033] Figure 1C This is a diagram illustrating the container used in embodiments of the present invention, and is being... Figure 1B An enlarged view of the area enclosed by the dotted line.

[0034] Figure 2 This is a schematic diagram of the container manufacturing apparatus according to this embodiment.

[0035] Figure 3 (a) to (g) are schematic diagrams representing the processes of the container manufacturing method.

[0036] Figure 4 (a) to (e) are schematic diagrams representing the main actions in the process of container manufacturing.

[0037] Figure 5 This is a flowchart of the container manufacturing process.

[0038] Figure 6 It is a graph showing the relationship between melting and film elongation.

[0039] Figure 7 This is a graph showing the relationship between the melting point and the descent speed of the second forming die.

[0040] Figure 8A This is a diagram showing a modified example, illustrating the state after the extrusion section comes into contact with the film.

[0041] Figure 8B This is a diagram showing a modified example, illustrating the state of the film after it has been cut by the extrusion section.

[0042] Figure 9 This is a schematic diagram showing an existing container manufacturing apparatus. Detailed Implementation

[0043] Hereinafter, embodiments of the container manufacturing apparatus and container manufacturing method according to the present invention will be described with reference to the accompanying drawings. The embodiments described below are for illustrative purposes and are not intended to limit the scope of the invention. Therefore, those skilled in the art will be able to substitute these elements or all elements with equivalent embodiments, but these embodiments are also included within the scope of the present invention.

[0044] (Implementation Method)

[0045] Reference Figure 1A , Figure 1B , Figure 1C ,as well as Figure 2 The structure of a container manufacturing apparatus according to one embodiment of the present invention will be described below. In the figures, the side of the container manufacturing apparatus where the second forming mold is disposed is designated as the upper side, and the side where the first forming mold is disposed is designated as the lower side. These terms are used for illustrative purposes and do not limit the direction in which the embodiment of the present invention is actually used. Furthermore, the technical scope described in the claims should not be interpreted in a limited manner based on these terms.

[0046] The container manufacturing apparatus and method described in this embodiment are for manufacturing composite containers by tightly adhering a sheet-like film formed of resin to the inner surface of a paper container.

[0047] (Containers used in container manufacturing facilities)

[0048] The paper container used in this embodiment will be described with reference to FIG1. Figure 1A It is a diagram showing the appearance of a paper container. Figure 1B Is Figure 1A A cross-sectional view cut at the cut line of line AA. Figure 1C It was by Figure 1B An enlarged view of the area enclosed by the dotted line.

[0049] like Figure 1A , Figure 1B As shown, container 10 is a cylindrical paper container used to hold beverages such as juice and coffee, or food such as pasta, creamy roasted dishes, and beef rice. Container 10 has a body 11 and a bottom 12. The cross-sectional shape of the body 11 is tapered towards the bottom. The body 11 is formed by shaping a sheet of blank cut from the original paper into a cylindrical shape and then fitting the two ends of the blank together. The fitted portion is called the seam 13. The bottom 12 is a plate-like component that closes the lower opening of the body 11.

[0050] A curled portion 11a is formed at the upper opening of the body portion 11, with its periphery rolled outwards. The curled portion 11a is a flange that protrudes outwards from the upper opening of the body portion 11, forming a ring shape when viewed from above. The lower end of the body portion 11 is folded inwards to form a folded-back portion 11b. The bottom 12 has a peripheral wall 12a formed by bending the outer periphery downwards. Figure 1B , Figure 1C As shown, the peripheral wall 12a of the bottom 12 is inserted into the space formed by the folding back of the body portion 11b, thereby closing the lower opening of the body portion 11. The folding back portion 11b and the peripheral wall 12a are bonded together with an adhesive material, but the folding back portion 11b and the peripheral wall 12a are not bonded together entirely, but have bonded areas (bonded areas) and unbonded areas (non-bonded areas). The non-bonded space formed by the non-bonded areas is used to expel air sealed between the film FL and the inner surface of the container 10 when the film FL is tightly adhered to the inner surface of the container 10.

[0051] (Container manufacturing apparatus)

[0052] The container manufacturing apparatus is an apparatus for manufacturing composite containers by bonding a resin film tightly to the inner surface of a paper container 10. Figure 2 The overall structure is shown in the figure. The container manufacturing apparatus 1 includes: a first forming mold 20, a second forming mold 30, a film holding part 40, a heater control part 50, an air control part 60, a lifting drive part 70, an exhaust part 80, and a control device 90.

[0053] The first forming mold 20 is a forming mold having a recess for inserting the container 10. The first forming mold 20 has a cylindrical cavity 21 and a disc-shaped base 22 disposed at the bottom of the cavity 21. An annular first film holding member 41 is disposed on the outer periphery of the first forming mold 20. A spring 24, which serves as a telescopic member, is connected to the lower part of the first film holding member 41. In addition, the cavity 21, the base 22, and the spring 24 are positioned and fixed on the base 23.

[0054] The cavity 21 has a body portion 11 that tapers from top to bottom and receives the container 10. A mounting portion 21a for holding the coiled portion 11a of the container 10 is formed at the upper end of the cavity 21. The mounting portion 21a has a width and shape sufficient to hold the coiled portion 11a, which is annular when viewed from above.

[0055] The base 22 has a flat surface on which the bottom 12 of the container 10 rests, and together with the cavity 21 forms a first molding die 20 for receiving the container 10. A gap G is formed between the upper outer periphery of the base 22 and the cavity 21, through which the folded-back portion 11b and the peripheral wall 12a of the container 10 are inserted. A venting passage 25 for air passage is formed between the inner periphery of the cavity 21 and the outer periphery of the base 22, and between the bottom of the base 22 and the base 23. A venting passage 26 communicating with the venting passage 25 is formed on the base 23 and connected to the exhaust portion 80 described later. Air between the inner periphery of the cavity 21 and the outer periphery of the base 22, and air between the bottom of the base 22 and the base 23 are drawn in by the exhaust portion 80 and discharged to the outside via the venting passages 25 and 26. In addition, the air generated during the process of sealing the film FL to the inner surface of the container 10 and being sealed between the inner surface of the container 10 and the film FL is also discharged to the outside through the exhaust section 80 via the non-adhesive space of the container 10 and the ventilation passages 25 and 26.

[0056] The annular first film holding member 41 is a member with a flat upper surface that holds and retains the film FL between itself and the second film holding member 42 (described later). When a force is applied from above to the first film holding member 41, the spring 24 mounted at its lower part contracts, causing the first film holding member 41 to move downwards. In this embodiment, a spring 24 is used, but the telescopic member is not limited to a spring 24; other members such as a pneumatic cylinder that extends and retracts by air pressure can also be used.

[0057] The film FL used in this embodiment typically has a three-layer structure. That is, the film FL, from the adhesive side of the base paper, sequentially comprises an adhesive layer, an intermediate layer, and a substrate layer supporting the adhesive layer and the intermediate layer. The substrate layer is a layer possessing water resistance and chemical resistance, and can be, for example, polypropylene (PP) or polyethylene (PE). The intermediate layer is the layer that primarily inhibits pinhole formation and can be a laminate of nylon (Ny) and ethylene-vinyl alcohol resin (EVOH), or a laminate of ionomer and EVOH. The adhesive layer is the layer that adheres to the base paper of the paper container and uses polyolefins such as PP and PE, or their modified resins.

[0058] The second forming mold 30 is configured to face the opening of the first forming mold 20, and includes a mold body 31 and a heater section 32.

[0059] The lower surface of the mold body 31 has a curved surface 31a that bends upward. When air is drawn in by the air control unit 60 (described later), the thin film FL is adsorbed onto the curved surface 31a.

[0060] Multiple vent holes 35 are formed on the curved surface 31a of the mold body 31, and air is drawn in or discharged from the multiple vent holes 35 by the air control unit 60. The multiple vent holes 35 converge and communicate with the vent hole 36 formed in the heater section 32 disposed on the upper part of the mold body 31. The vent hole 36 is connected to the air control unit 60. When air is drawn in from the vent holes 35, the film FL held by the first film holding member 41 and the second film holding member 42 is adsorbed onto the curved surface 31a. When compressed air is discharged from the vent holes 35, the film FL adsorbed onto the curved surface 31a separates from the curved surface 31a and is formed inside the first forming mold 20.

[0061] A downwardly protruding annular protrusion 34 is formed on the lower outer periphery of the mold body 31. The inner surface of the protrusion 34 has an inclined wall 34a that slopes from the front end of the protrusion 34 toward the mounting portion 21a. The inclined wall 34a and the mounting portion 21a are used to clamp the curled portion 11a and the film FL, so that the film FL is in close contact with the curled portion 11a.

[0062] A heater section 32 is disposed on the upper part of the mold body 31 and contains multiple rod-shaped heaters 33. The heater section 32 is formed of a cubic block, and the multiple rod-shaped heaters 33 are arranged in a parallel, flat position within the block. The heaters 33 heat the mold body 31, melt the thin film FL through the heated protrusions 34, and soften the thin film FL adsorbed on the heated curved surface 31a.

[0063] A vent 36 extending vertically is formed in the heater section 32. The vent 36 includes an intake vent 36a and an exhaust vent 36b. Under the control of the air control unit 60 (described later), the intake vent 36a is used as a vacuum path during vacuuming, and the exhaust vent 36b is used as a compressed air path during compressed air forming.

[0064] An annular second film holding member 42 is disposed on the outer periphery of the second forming mold 30. The second film holding member 42 is configured to face the first film holding member 41, and the second film holding member 42 descends to contact the first film holding member 41, holding the film FL between the second film holding member 41 and the first film holding member 41. The first film holding member 41 and the second film holding member 42 constitute the film holding portion 40.

[0065] The film holding portion 40 is not heated by the heater 33, and the film FL held by the film holding portion 40 is held at a low temperature. The protrusion 34 is overheated, and the film holding portion 40 is not heated, so the film FL can be easily melted by the protrusion 34 using this temperature difference.

[0066] The second film holding member 42 and the second forming mold 30 are connected to the upper part of the container manufacturing apparatus 1 via a connecting member 43 connected to the upper part of the second film holding member 42 and a cylinder 71 connected to the upper part of the second forming mold 30, and move together.

[0067] The heater control unit 50 performs the switching on / off and temperature control 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 that is to be melted by the protrusion 34. The melting point of the film varies depending on the main resin material used in the film; if it is polypropylene (PP) based, it is a temperature of 160°C or higher, and if it is polyethylene (PE) based, it is a temperature of 130°C or higher.

[0068] The air control unit 60 is a device that switches between drawing air from the vent 35 of the second forming mold 30 and discharging compressed air. Air drawing is performed using, for example, a vacuum pump, and compressed air discharging is performed using an air compressor. When the film FL is adsorbed onto the curved surface 31a, drawing is performed via the vacuum pump through the drawing vent 36a. When the film FL is compressed and formed, compressed air is discharged from the curved surface 31a via the discharging vent 36b using an air compressor. The air control unit 60 switches between the operation of the vacuum pump and the air compressor to perform drawing and discharging.

[0069] The lifting drive unit 70 is a device that raises and lowers the second forming mold 30 and the second film holding member 42 as a single unit. For example, a servo press can be used as the lifting drive unit 70. A servo press is a device that raises and lowers the second forming mold 30 and the second film holding member 42 by driving a servo motor. As the lifting drive unit 70, not only mechanical presses such as servo presses can be used, but also various presses such as hydraulic presses can be used. In addition, in the process of pressurizing the curled portion 11a of the container 10, which will be described later, the curled portion 11a can be pressed separately by lowering only the cylinder 71.

[0070] When the second film holding member 42 is lowered by the lifting drive unit 70, it contacts the first film holding member 41, clamping and holding the film FL. After contacting the film FL, the second film holding member 42 lowers further, and the spring 24 located at the lower part of the first film holding member 41 is compressed as it descends, stretching the film FL clamped by the holding member 40 downwards. The first film holding member 41, the second film holding member 42, and the spring 24 function as tension generating parts that generate downward tension in the film FL.

[0071] The venting section 80 discharges air between the inner periphery of the cavity 21 and the outer periphery of the platform 22, air between the lower surface of the platform 22 and the base 23, and air between the inner surface of the container 10 and the thin film FL via venting passages 25 and 26, thereby ensuring that the thin film FL is in close contact with the inner surface of the first molding die 20. For example, a vacuum pump can be used as the venting section 80.

[0072] The control device 90 controls the overall operation of the container manufacturing apparatus 1. Depending on the material of the film FL used, it performs controls such as temperature control of the heater 33 based on the heater control unit 50, air suction and discharge control of the second forming mold 30 based on the air control unit 60, lifting speed control of the lifting drive unit 70, and exhaust control of the exhaust unit 80. The control device 90 has a built-in CPU, which executes programs to perform control.

[0073] (Methods for manufacturing containers)

[0074] use Figures 3-5 A method for manufacturing a composite container by bonding a thin film FL tightly to a paper container 10 is described.

[0075] First, the control device 90 instructs the insertion device (not shown) to receive the container 10 into the recess of the first forming mold 20 (step S101). The curled portion 11a of the container 10 is placed on the placement portion 21a of the first forming mold 20 (the process of receiving the container into the first forming mold 20).

[0076] Next, the control device 90 instructs the film insertion device (not shown) to insert the film FL between the first forming mold 20 and the second forming mold 30. Figure 3 (a) (step S102). Then, the control device 90 instructs the lifting drive unit 70 to begin the descent of the second forming mold 30 (step S103). As the second forming mold 30 descends, the first film holding member 41 contacts the second film holding member 42, thereby holding the film FL ( Figure 3(b) (Step S104) (The process of holding the film). At this time, the film FL is held in a straight line, and this position is taken as the initial position. The length from the upper surface of the base 23 to the upper end of the spring 24 is 75 mm (hereinafter referred to as "the length of the spring"). In addition, the control device 90 instructs the air control unit 60 to start drawing air from the vent 35. The air drawing based on the air control unit 60 continues from when the film FL is held until the film FL is separated from the second forming mold 30.

[0077] As the second forming mold 30 descends further, the first film holding member 41 and the second film holding member 42 holding the film FL descend, and the held film FL is stretched obliquely downward and descends 1 mm from the initial position. Figure 3 (c) Figure 4 (a) At this time, the spring 24 located at the lower part of the first film holding member 41 retracts downward, and the length of the spring becomes 74 mm.

[0078] As the first film holding member 41 and the second film holding member 42 descend further, and the held film FL descends 2 mm from its initial position and is stretched downward, the inclined wall 34a on the inner side of the protrusion 34 of the second forming mold 30 contacts the film FL. Figure 3 of (d), Figure 4 (b)). The contact portion between the inclined wall 34a and the thin film FL is indicated by a dashed circle. The spring 24 is contracted to 73 mm.

[0079] Furthermore, as the first film holding member 41 and the second film holding member 42 descend, and the held film FL descends 5 mm from its initial position and is stretched downwards, the film FL is clamped by the inclined wall 34a inside the protrusion 34 of the second forming mold 30 and the curled portion 11a of the container 10, and the inside of the curled portion 11a is sealed. Figure 3 of (e) Figure 4 (c) At this time, air is drawn from the vent 35 through the air control unit 60, so the film FL is adsorbed onto the curved surface 31a of the second forming mold 30. In addition, the curved surface 31a is heated by the heater 33 at the same time, so the film FL is softened (step S105). The spring 24 is contracted to 70mm.

[0080] Furthermore, when the first film holding member 41 and the second film holding member 42 descend, the held film FL descends 7mm from its initial position and is stretched downwards. When the second forming mold 30 presses the curled portion 11a by the cylinder 71, the curled portion 11a is crushed, and flange pressure is applied. Figure 3 of (f), Figure 4(d) (step S106). The inner side of the container 10 is sealed by applying pressure to the flange, preventing air leakage from the coiled portion 11a due to deformation during air compression forming. The spring 24 is contracted to 68 mm.

[0081] Furthermore, when the first film holding member 41 and the second film holding member 42 descend, and the held film FL descends 8 mm from its initial position, the film FL is melted by the protrusion 34 heated by the heater 33. Figure 3 of (g), Figure 4 (e) (step S107) (the process of melting the film). The film FL is melted by the inner corner of the front end of the protrusion 34 (part of the inclined wall 34a), so the film FL is melted near the mounting portion 21a, which can shorten the length of the film FL protruding from the mounting portion 21a. The spring 24 is contracted to 67mm.

[0082] The control device 90 instructs the air control unit 60 to discharge compressed air from multiple vents 35 of the second forming mold 30 simultaneously with the melting action. The softened film FL expands inside the first forming mold 20 due to the compressed air, performing vacuum forming. In addition, the control device 90 instructs the exhaust unit 80 to discharge the air sealed between the inner surface of the container 10 and the film FL through the non-adhesive space between the body 11 and the bottom 12 of the container 10, and the vents 25 and 26. By venting, the container 10 and the film FL are sealed together, and vacuum forming is performed to manufacture the composite container (step S107) (the process of sealing the inner surface of the container).

[0083] When the forming is finished, the control device 90 instructs the lifting drive unit 70 to raise the second forming mold 30 and the first film holding member 42, and remove the manufactured composite container from the first forming mold 20 (step S108).

[0084] (Example)

[0085] To melt the film, it has been verified that meeting certain conditions is more effective. These conditions include: the temperature of the protrusion 34 of the second forming mold 30, the elongation of the film FL generated when the first film holding member 41 and the second film holding member 42 descend, and the descent speed of the first film holding member 41 and the second film holding member 42. Experiments have confirmed which of the above conditions is optimal.

[0086] <Relationship between temperature of protrusion and melting point>

[0087] Table 1 shows the heating temperature of the protrusion 34 and the presence or absence of the film FL being cut. In this embodiment, the film thickness is 105 μm, and its structure, from the inner surface of container 10 towards the paper side, is a PE / AD / EVOH / AD / PE based adhesive resin. From the inner surface of container 10 towards the paper side, the weight % (wt%) of each layer is 43 / 3.5 / 7 / 3.5 / 43, indicating it is a PE-based resin-based film.

[0088]

[0089] As shown in Table 1, the FL film did not melt at room temperature (25°C and 70°C), melted by about 30% at 100°C, melted by 90% at 120°C, and reliably melted at 130°C and 135°C. Thus, it can be confirmed that if the temperature of the protrusion 34 is above 130°C, the melting point of the PE-based raw material used as the base of the FL film, it can melt.

[0090] The temperature is set above the melting point of the resin material used as the base material, so that the film FL can melt. In this embodiment, a PE-based resin material is used, but in a film FL based on, for example, a PP-based resin material, a temperature of 160°C or higher as the melting point is required. The temperature of the protrusion 34 can be set according to the type of resin material used as the base material.

[0091] <Relationship with film elongation>

[0092] Table 2 shows the relationship between the temperature of the protrusion 34 of the second forming die 30 and the elongation of the film FL. For example... Figure 6 As shown, the elongation of the film FL is defined as the distance from the apex of the curled portion 11a of the container 10 to the holding end of the film FL held by the first film holding member 41 and the second film holding member 42.

[0093]

[0094] As shown in Table 2, it can be confirmed that even when the heating temperature of the protrusion 34 is above the melting point of the resin material used as the base material, the film does not melt when the elongation of the film FL is less than 0.5 mm and the tensile strength is less than 5.4 MPa. Preferably, the elongation of the film FL is more than 0.8 mm and a tensile strength of more than 9.2 MPa is applied to the film FL. Here, tensile strength refers to the value derived from the tensile strength test results of the film monomer JIS 7113 test.

[0095] <Relationship with the descent speed of the second forming die>

[0096] Table 3 shows the relationship between the descent speed of the second forming die 30 and the temperature. For example... Figure 7 As shown, the conditions for melting were verified by changing the speed at which the heated second forming mold 30 descended in the direction of the arrow.

[0097]

[0098] As shown in Table 3, it was confirmed that when the temperature of the protrusion 34 of the second molding die 30 is above the melting point of the main resin material of the film FL used, and the elongation of the film FL is 0.8 mm or more, while applying tension to the film FL with a tensile strength of 9.2 MPa or more, and while the second molding die 30 is lowered at a speed of 100 mm / sec or more, the melting effect is high.

[0099] (Modified example)

[0100] In this embodiment, the first film holding member 41 and the second film holding member 42 lower while clamping the film FL, thereby applying downward tension to the film FL to achieve melting. However, the first film holding member 41 and the second film holding member 42 may also apply downward tension to the film FL through other members without moving.

[0101] As shown in Figure 8, this modified example is characterized in that an extrusion member 400 is disposed between the first forming mold 20 and the second forming mold 30 and the first film holding member 41 and the second film holding member 42.

[0102] like Figure 8A As shown, after the curled portion 11a of the container 10 is pressed flat by the second forming die 30, the extrusion member 400 descends and applies downward tension to the film FL, thereby... Figure 8B As shown, the thin film FL was melted.

[0103] The extrusion member 400 is positioned near the protrusion 34 of the second forming die 30, thus enabling the film FL to be melted 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.

[0104] Thus, according to this embodiment, the thin film FL is melted by the heated protrusion 34 without using a cutting blade, so the container manufacturing apparatus 1 can be designed compactly and maintenance such as replacing the cutting blade is not required.

[0105] According to this embodiment, the inclined wall 34a of the protrusion 34 and the mounting portion 21a clamp the curled portion 11a of the container 10 and the film FL to melt the film FL, thus enabling the film FL to be melted near the curled portion 11a. Therefore, the operation of rolling up the outer periphery of the melted film FL becomes easy and will not damage the user's mouth.

[0106] According to this embodiment, the inner surface of the protrusion 34 is set as an inclined wall 34a, so that the molten film FL does not adhere to the protrusion 34 and can be smoothly melted off.

[0107] According to this embodiment, the action of adsorbing the film FL onto the curved surface 31a to soften the film FL and the action of clamping the curled part 11a and the film FL by the mounting part 21a and the protrusion 34 are performed simultaneously. Therefore, the inner space of the mounting part 21a and the protrusion 34 can be sealed so that the film FL is uniformly and tightly attached to the inner surface of the container 10.

[0108] According to this embodiment, the film FL is melted while tension is applied to the bottom side of the first forming mold 20, thus the film FL can be easily cut.

[0109] According to this embodiment, the container 10 is cylindrical, and together with the annular protrusion 34, it can easily melt the thin film FL.

[0110] In this embodiment, the container 10 is described as a cylindrical paper container, but the shape is not limited to a cylindrical shape. For example, it could also be a rectangular box-shaped container when viewed from above. In the case of using a box-shaped container, unlike the cylindrical container 10, the flange is not formed by the curled portion 11a, but by a flat piece of paper protruding outward from the opening of the box.

[0111] In this embodiment, the second forming mold 30 and the second film holding member 42 are described as being integrated, but they can also be separate components. By making them separate components, the tension applied to the film FL can be precisely controlled.

[0112] In this embodiment, it is described that the second forming mold 30 descends and comes into contact with the first forming mold 20, but the first forming mold 20 and the second forming mold 30 only need to move relative to each other and approach each other, and the first forming mold 20 can also rise.

[0113] In this embodiment, it is described that the protrusion 34 and the curved surface 31a are heated by the heater 33 of the heater section 32. The heater 33 can also be divided into a heater for heating the protrusion 34 and a heater for heating the curved surface 31a. By separating the heaters, the temperature control of the protrusion 34 and the curved surface 31a can be implemented independently, and finer temperature control can be achieved. In addition, the heater 33 can also be built into the mold body 31.

[0114] In this embodiment, the heater 33 is described as being configured such that multiple rod-shaped heaters lie flat in parallel, but a ring-shaped heater that appears when viewed from above can also be used. Additionally, a cooling device can be installed on the second forming mold 30 to perform temperature control.

[0115] In this embodiment, it is described that the inner surface of the protrusion 34 has an inclined wall 34a, but the inner surface of the protrusion 34 may also be a shape that is straight and elongated without inclination.

[0116] In this embodiment, the composite container is manufactured using both pneumatic forming and vacuum forming to form the composite container, but either pneumatic forming or vacuum forming can also be used for manufacturing.

[0117] In this embodiment, the held film FL is described as being stretched diagonally downwards to achieve melting, but the stretching direction can also be diagonally upwards. In this case, the film holding portion 40 is raised, and the film FL is melted at the outer corner of the front end of the protrusion 34. To shorten the length of the film FL, the stretching direction is more preferably diagonally downwards.

[0118] This application is based on Japanese Patent Application No. 2023-189854, filed on November 7, 2023. The description, claims, and drawings of Japanese Patent Application No. 2023-189854 are incorporated herein by reference in their entirety.

[0119] Industrial availability

[0120] This invention can be used for container manufacturing methods and container manufacturing apparatus for manufacturing composite containers.

[0121] Explanation of reference numerals in the attached figures

[0122] 1... Container manufacturing apparatus; 10... Container; 11... Body section; 11a... Curved section; 11b... Fold-back section; 12... Bottom; 12a... Peripheral wall; 13... Seam section; 20... First forming die; 21... Cavity; 21a... Mounting section; 22... Base; 23... Platform; 24... Spring; 25, 26... Ventilation passage; 30... Second forming die; 31... Die body; 31a... Curved surface; 32... Heater section; 33... Heater; 34... Protrusion; 34a... Inclined wall; 35, 36 Vent hole; 36a... Suction vent hole; 36b... Discharge vent hole; 40... Film holding part; 41... First film holding member; 42... Second film holding member; 43... Connecting member; 50... Heater control part; 60... Air control part; 70... Lifting drive part; 71... Cylinder; 80... Exhaust part; 90... Control device; 100... Container manufacturing apparatus; 110... Container; 200... First forming die; 300... Second forming die; 301... Cutting knife; 400... Extrusion member.

Claims

1. A method for manufacturing a container, comprising bonding a thin film to the inner surface of a container having a flange portion protruding outward from the periphery of an opening, thereby manufacturing a composite container, wherein... It has the following processes: The process of receiving the container in a concave first forming mold; The process of moving the second forming mold to the first forming mold, wherein the second forming mold is configured to face the first forming mold and has a protrusion disposed on the outer periphery of the flange portion when the container is received in the first forming mold; The process of holding a film between the first forming mold and the second forming mold; The process of using air pressure difference to ensure the maintained film is tightly adhered to the inner surface of the container; and The process of melting the film through the protrusion.

2. The container manufacturing method according to claim 1, wherein, The process of receiving the container in the first forming mold includes the process of placing the flange portion on a mounting portion formed in the opening of the first forming mold. In the melting process, the film is melted off the outside of the mounting portion through the inner surface of the protrusion.

3. The container manufacturing method according to claim 2, wherein, The process of adhering to the inner surface of the container includes heating the film.

4. The container manufacturing method according to claim 1, wherein, The melting process includes a process of generating tension on the bottom side of the first forming mold of the film.

5. A container manufacturing apparatus for manufacturing a composite container by adhering a thin film to the inner surface of a container having a flange portion protruding outward from the periphery of an opening, wherein... have: A concave first forming mold, which houses the container; A second forming mold, configured to face the opening of the first forming mold, includes a heater; and A film holding portion is disposed on the outer periphery of the first forming mold and the second forming mold to hold the film inserted between the first forming mold and the second forming mold. The first forming mold has a mounting portion for mounting the flange portion. The second forming mold has a protrusion formed on a side opposite to the first forming mold, and is positioned on the outer periphery of the mounting portion when the container is received in the first forming mold. The protrusion, heated by the heater, melts the film held by the film holding part on the outside of the mounting part.

6. The container manufacturing apparatus according to claim 5, wherein, The inner surface of the protrusion has an inclined wall that slopes from the front end of the protrusion toward the mounting portion. The protrusion causes the film to adhere tightly to the inclined wall, thereby achieving melting.

7. The container manufacturing apparatus according to claim 5, wherein, The container manufacturing apparatus further includes a tension generating section that applies tension to the bottom side of the container by means of the film held by the film holding section.

8. The container manufacturing apparatus according to claim 7, wherein, The tension generating part generates tension in the film by moving the film holding part toward the bottom side of the first forming mold.

9. The container manufacturing apparatus according to claim 7, wherein, The tension generating part is an extrusion component disposed between the first forming die, the second forming die, and the film holding part. The extrusion component moves toward the bottom side of the first forming die, thereby generating tension in the film.

10. The container manufacturing apparatus according to claim 5, wherein, The container is cylindrical in shape.

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