JP2021095215A5 - - Google Patents

Description

1 and 2 show the overall structure of a cup-shaped container (1) according to an embodiment of the present invention, and the container (1) has a body (2) formed from a body blank (20A). and a bottom body (3) molded from a bottom body blank (30A) are integrally joined together.
The body (2) has a tapered cylindrical shape, and is formed by joining a fan-shaped body blank (20A) by overlapping both end edges thereof, as shown in FIG. Therefore, the body part (2) has an overlap part (21) extending along the height direction thereof.
A folded part (22) folded inward is formed at the lower opening edge of the body (2).
Further, a flange portion (23) bent outward is provided at the upper opening edge of the body (2). The flange portion (23) is folded downward and formed into a substantially horizontal flat shape. Note that the flange portion (23) may be curled downward to have a substantially arcuate cross section.
The bottom body (3) has a substantially inverted U-shaped cross section, and has a circular horizontal bottom part (31) and a hanging part (32) extending downward from the outer peripheral edge of the bottom part (31). As shown in 6, it is formed by drawing a circular bottom body blank (30A).
Then, the outer surface of the hanging portion (32) of the bottom body (3) is joined to the inner surface of the lower end portion (2a) of the body (2), and the folded portion (22) of the body (2) is attached to the hanging portion (32). The body (2) and the bottom body (3) are integrated by being joined to the inner surface of the body (see FIGS. 2 and 10).

As shown in FIG. 3(a), the fuselage blank (20A) includes a metal foil layer (201) and an inner layer laminated on the inner side of the fuselage (2) of both sides of the metal foil layer (201). A laminate ( 20) and does not have a paper layer.
In addition, as shown in FIG. 3(b), the bottom body blank (30A) is also attached to the metal foil layer (301) and the surface of the metal foil layer (301) that is on the upper side of the bottom body (3). The laminated upper heat-fusible resin layer (302) and the lower heat-fusible resin layer (303) laminated on the lower side of the bottom body (3) of both surfaces of the metal foil layer (301). ) and does not have a paper layer.
The thickness of each laminate (20) (30) is preferably less than 250 μm, more preferably less than 200 μm. By setting the thickness of each laminate (20) and (30) within the above range, the flange portion of the body (2) ( 23), the part formed by the overlap part (21) may become too large, or the lower end (2a) of the body (2) and the folded part (22) and the hanging part (3) of the bottom body (3 ) may become too large. 32) , the problem of unstable bonding with the material is reliably avoided.

The heat-fusible resin layers (202) (203) (302) (303) constitute the inner and outer surfaces of the container (1), protect the metal foil layers (201) (202), and It plays the role of imparting moldability to the bodies (20) and (30), and also serves to join both end edges of the fuselage blank (20A), and to join the lower end (2a) and folded parts of the fuselage (2). (22) and the hanging part (32) of the bottom body (3) function as a heat fusion layer when joining.
The heat-fusible resin layer (202) (203) (302) (303) is, for example, a general-purpose film such as polypropylene (PP) film or polyethylene (PE) film that has heat-fusibility, or a film on which these are pasted. Although it is composed of a composite film, unstretched polypropylene film (CPP) is particularly suitable because it has excellent heat resistance and drawability. The heat-fusible resin layers (202), (203), (302), and (303) are made of maleic acid-modified polyethylene, maleic acid-modified polypropylene, ethylene-vinyl acetate, epoxy resin, shellac resin, etc. instead of the above film. It may be formed by a coating layer.
The thickness of the heat-fusible resin layer (202) (203) (302) (303) is preferably 5 to 80 μm, more preferably 10 to 60 μm. By setting the thickness of the heat-fusible resin layers (202), (203), (302), and (303) within the above range, the joints between both end edges of the fuselage blank (20A) and the fuselage (2) Sufficient adhesive strength can be obtained at the joint between the lower end (2a) and folded part (22) and the hanging part (32) of the bottom body (3), and the upper surface of the flange part (23) of the body (2) The level difference in the portion formed by the overlap portion (21) can be made gentler, and the sealing performance when sealed with the lid material is improved.

Next, an example of a method for forming a cup-shaped container (1) using the above-mentioned laminates (20) and (30) will be explained.
First, the laminate (20) is punched out into a fan shape of a predetermined size to form a fuselage blank (20A) (see FIG. 5(a)).
Further, the laminate (30) is punched out into a circular shape of a predetermined size to form a bottom body blank (30A) (see FIG. 6(a)).
Then, the bottom body blank (30A) is subjected to drawing processing using a forming apparatus (4) shown in FIG. 8. The forming device (4) includes an annular die (41) and a wrinkle presser (42) arranged vertically facing each other, and a punch (43) that can be moved up and down the center of the die (41) and the wrinkle presser (42). It is equipped with The forming process is performed by placing a bottom body blank (30A) whose surface is coated with lubricant as necessary between the die (41) and the wrinkle presser (42). This is done by lifting the punch (43) while pressing the outer periphery of the die (41) with a predetermined pressure using the wrinkle presser (42). In this way, the bottom body (3) having a substantially inverted U-shape in cross section, consisting of the bottom part (31) and the hanging part (32), can be formed (see FIG. 6(b)).
Next, the bottom body (3) is set on the top surface of a substantially truncated conical mold (not shown) so that the top surface of its bottom (31) overlaps, and then the body After wrapping the blank (20A) and overlapping both end edges thereof, the inner heat-fusible resin layer (202) and the outer heat-fusible resin layer that constitute the mutually overlapping surfaces of the overlap part (21) are bonded. By heat-sealing the plastic resin layer (203), a tapered cylindrical body (2) is formed. The means for thermally fusing the overlap portion (21) may be heat sealing using a hot plate, high frequency sealing, ultrasonic sealing, or the like.
Here, heat sealing is performed, for example, when the inner heat-fusible resin layer (202) and the outer heat-fusible resin layer (203) are made of unstretched polypropylene film (CPP), sealing temperature: 160 to 220°C. It is preferable to carry out the process under the following conditions: load: 80 to 200 kgf, and sealing time: 1 to 5 seconds. In addition, when the inner heat-fusible resin layer (202) and the outer heat-fusible resin layer (203) are made of polyethylene film (PE), sealing temperature: 140-220°C, load: 80-200°C.
kgf and sealing time: preferably 1 to 5 seconds. In other words, in the case of heat sealing, the temperature is 20 to 40°C higher than the melting point of the resin constituting the heat-fusible resin layers (202) and (203) from both sides of the overlapped fuselage blanks (20A). It is preferable to carry out heating at a certain temperature.
In addition, high-frequency sealing is performed under the following conditions, for example: output: 0.5 to 1.5 kW, sealing time: 3 to 5 seconds, distance to the coil: 0.5 to 15 mm, and load: 100 to 200 kgf. preferable.
Next, as shown in FIG. 10, the lower opening edge of the body (2) is folded inward, and the folded part (22) is inserted into the hanging part of the bottom body (3) using a disc-shaped rotary mold (not shown). (32), the inner heat fusion that forms the mutually overlapping surfaces of the lower end (2a) and folded part (22) of the body (2) and the hanging part (32) of the bottom body (3) The body (2) and the bottom body (3) are bonded by heat-sealing the adhesive resin layer (202), the upper heat-fusible resin layer (302), and the lower heat-fusible resin layer (303). Join and integrate. Thermal fusion of these heat-adhesive resin layers (202), 302, and 303 is usually performed by heat sealing using a hot plate, etc., but it can also be performed by high-frequency sealing, ultrasonic sealing, etc. Good too. Suitable conditions for heat sealing and high frequency sealing are the same as those for heat sealing the overlap portion (21) of the body (2).
In addition, the upper opening edge of the body (2) is curled outward using a predetermined curling mold (not shown) and pressurized in the vertical direction to form it into a flat shape. ) (see Figure 10).
In this way, the cup-shaped container (1) shown in FIGS. 1 and 2 is obtained.

Furthermore, as shown in FIG. 4, the inner end surface of the fuselage blank (20A) located inside the fuselage (2) Preferably, it is covered with an inner resin reservoir (R1) formed when the fusible resin layer (202) and the outer heat-fusible resin layer (203) are heat-sealed. Although not shown, the outer end surface of the fuselage blank (20A) located on the outside of the fuselage (2) is also connected to the inner thermal melting surface that constitutes the mutually overlapping surfaces of both end edges of the fuselage blank (20A). It may be covered by an outer resin pool formed when the adhesive resin layer (202) and the outer heat-fusible resin layer (203) are heat-sealed.
When the above-mentioned inner resin reservoir (R1) and outer resin reservoir are heat-sealed the overlapped end edges of the fuselage blank (20A), the inner resin reservoir (R1) and the outer resin reservoir are A part of the fusible resin layer (202) and the outer heat fusible resin layer (203) are melted, and the melted resin is pushed out in the width direction of the overlap part (21) by the pressure applied during heat fusing. It is formed by In addition, the inner resin reservoir (R1) contains the inner heat-fusible resin layer (202) and the outer heat-fusible resin layer (203) that constitute the inner end surface of the fuselage blank (20A), and the inner end surface . A part of the inner heat-fusible resin layer (202) adjacent to the inner heat-fusible resin layer (202) is also formed by melted resin, and the outer resin reservoir is formed by the inner heat-fusible resin constituting the outer end surface of the fuselage blank (20A). It is considered that the layer (202), the outer heat-fusible resin layer (203), and a part of the outer heat-fusible resin layer (203) close to the outer end surface are also formed of molten resin.
These resin reservoirs (R1) are formed by, for example, sealing conditions during heat fusion (sealing temperature, pressure,
It can be formed by controlling the sealing time, sealing range, etc., or by appropriately setting the structure of the fuselage blank (20A).