JP2016087983A - Top curl molding metal mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing device for minimizing a burr and the edge, and capable of molding a paper cup having an easily drinking top curl part, without turning up the burr, without contacting a top curl upper die with these outsides even if the burr and the edge are caused.SOLUTION: A top curl molding metal mold of a paper cup is provided for molding a top curl part 13 by rolling in while guiding to the outside along a curved surface-shaped groove part that is applied to an upper end opening part peripheral edge of the paper cup in which a trunk part and a bottom part are joined, to a top curl molding metal mold, and the top curl molding metal mold is constituted of an upper die and a lower die, and the curved surface-shaped groove part is divided into a groove part of the upper die and a groove part of the lower die, and is constituted so as to form the curved surface-shaped groove part by bringing the upper die and the lower die into close contact with each other, and a parting 50 of the upper die and the lower die is provided just under a maximum outer diameter part 32 of a top curl in a position of the molding top curl.SELECTED DRAWING: Figure 1

Description

  The present invention relates to processing of a paper cup in which a punching blank of a barrel member and a bottom member is bonded to a bottom portion and a trunk portion by a heat-sealing or high-frequency seal or the like and a trunk opening portion is top-curled in manufacturing a paper cup. It is.

  Conventionally, paper cups are roughly classified into beverage cups, food cups, medical cups, and the like depending on applications, and cold drinks such as juices and carbonated drinks and hot drinks such as coffee are used as beverage cups. Furthermore, for confectionery such as popcorn, a paper cup is also manufactured in which a polyethylene resin or a barrier layer is provided inside the paper cup and a lid is fused to the opening of the paper cup.

In these paper cups, if the cut end face remains as it is, the opening at the upper end not only hurts when the mouth is attached, but also because it has low strength, it is easy to deform and difficult to drink, it can not be covered, There are problems such as. Therefore, conventionally, the top portion of the opening end is wound and a top curl is provided to form a strong end portion.
For example, in Patent Document 1,
Top curl molding of a paper cup that forms the top curl part by winding the paper cup with the body part and the bottom part while guiding the periphery of the upper end opening of the paper cup along the curved groove provided on the curl mold. In processing, the curved groove portion is composed of a first curl portion and a second curl portion, and the first curl portion is pre-curled outward from the periphery of the upper end opening portion of the paper cup, and then the opening curl is defined by the second curl portion. In addition, while being guided along the curved groove portion, the top curl portion is strengthened by winding up to approximately one turn and 30 degrees and simultaneously reducing the diameter of the curved groove portion of the second curl portion to further wind the opening peripheral portion. A method for forming a top curl of a paper cup, which is characterized in that is formed.

In this molding method, after molding the precurl, the mold that molds the second curl part, the contact surfaces of the upper mold and the lower jig are in a horizontal plane, so the thermoplastic layered on the surface of the paper cup in the gap When the resin layer is sandwiched or pushed in, it flows into the gap between the contact surfaces and may cause burrs.
This defect was required to be improved because it could cause injury or pain when eating with a paper cup.

In Patent Document 2,
An ultrasonic welding apparatus for forming a top curl portion of a paper cup into a flat flange shape using an ultrasonic horn and a cup receiving mold, wherein the ultrasonic horn has a top curl portion of the paper cup on an outer peripheral portion of a tip. The outer cylindrical surface of the groove is parallel to the moving direction of the ultrasonic horn, and the inner circumference is equal to the finished outer diameter of the cup flange. An outer diameter regulating collar is formed, and the cup receiving mold has a space for storing and holding the paper cup body, and a cup holder having a donut shape at the upper end. The cup receiver has an inner diameter at the upper end portion of the paper cup. The outer diameter of the cup receiver is approximately equal to the outer diameter just below the top curl portion, and is parallel to the moving direction of the ultrasonic horn, and the outer diameter is on the outer cylindrical surface of the groove of the ultrasonic horn. Mating When the cup flange portion is formed by pressing the top curl portion of the paper cup with the bottom surface of the groove portion of the ultrasonic horn and the cup receiving upper surface of the cup receiving mold, the ultrasonic horn And an ultrasonic welding apparatus in which the cup receiving mold is not in direct contact.

For example, a mold as shown in FIG. However, as shown in FIG. 2-2 in which the top curl is formed, in this apparatus, the mold that is an ultrasonic horn that hits the outer shape is parallel to the movable direction of the lower top curl 4 and is configured by the upper end of the paper cup. The shape hits in the vertical direction with respect to the top surface. However, since the body member 10 is wound with a gradient, the top curl portion 13 is pressed against the upper mold groove portion 52 by the gradient. Then, the thermoplastic resin layer laminated on the surface of the paper cup is clamped while being rubbed, and the top curl portion is formed, so that it is sandwiched or pushed in and protrudes, thereby generating burrs and edges.
As shown in FIG. 3-1, the generated burrs and edges are such that the top curl upper mold 5 is located just outside these burrs 31 and edges, and the top curl lower mold 4 is lowered to take out the product. If it does so, it will be rubbed against the sliding surface 500 of the top curl upper mold | type 5, and the burr | flash 31 and edge will be turned up and it will protrude outside as FIG. 3-2.
Since the sliding surface 500 of the mold is inevitably metal, it cannot be held on a flat and clean surface. When rubbed against such a sliding surface 500 that cannot be mirrored, the burr 31 and the edge are turned up.
For this reason, when eating with the mouth placed against a paper cup, the burr or edge of the top curl 3 caused problems such as injury or pain.

JP 2004-330423 A JP 2009-184169 A

  Therefore, the object of the present invention is to minimize the burrs and edges, and even if burrs and edges occur, the top curl upper mold is not in contact with the outer sides of the burrs and the burrs are not turned up. A top curl mold capable of forming a paper cup having an easy top curl portion is provided.

The top curl mold of the paper cup according to claim 1 of the present invention is
The top of the paper cup that forms the top curl portion by winding it while guiding the periphery of the upper end opening of the paper cup to which the body portion and the bottom portion are joined along the curved groove provided on the top curl mold. In the curl mold
The groove portion is composed of an upper die and a lower die, and the curved groove portion is divided into an upper die groove portion and a lower die groove portion, and the upper die and the lower die are brought into close contact with each other so that the curved groove portion is formed. Configured to be formed,
A top curl molding die characterized in that an upper die and a lower die are parted immediately below the maximum outer diameter portion of the top curl at the position of the top curl to be molded.

A top curl mold for a paper cup according to claim 2 of the present invention is
The groove parting divided into the upper mold and the lower mold of the top curl mold is characterized in that the end of the upper mold on the product side is located inside the end of the lower mold. The top curl mold.

Moreover, the top curl mold of the paper cup according to claim 3 of the present invention is
A sliding surface for aligning the upper mold and the lower mold perpendicular to the parting surface is provided outside the groove parting divided into the upper mold and the lower mold of the top curl mold. Item 3. A top curl mold according to Item 1 or 2.

Moreover, the top curl mold of the paper cup according to claim 4 of the present invention is
The top curl mold according to any one of claims 1 to 3, wherein a curved surface is provided at the lower mold end of the product part in the parting of the upper mold and the lower mold of the top curl mold It is.

  The top curl mold of the paper cup of the present invention is less likely to generate burrs, and even if burrs or protrusions are generated, they will not rise, so even if the mouth contacts the paper cup, it may cause injury. It can produce paper cups that can be used with peace of mind.

FIG. 4 is a longitudinal sectional view of a paper cup top curl molding die according to the present invention in a state where molding of the top curl of the paper cup is started, and a partially enlarged view of a state where the top curl is being molded. FIG. 5 is a longitudinal sectional view of a conventional paper cup top curl molding die in a state where molding of the top curl of the paper cup is started, and a partially enlarged view of a state where the top curl is being molded. It is a partial expanded sectional view which shows the state which formed the top curl of a paper cup with the conventional top curl mold, and the burr has occurred in the rim, and the burr is in the state of being lifted by the rise of the horn. . It is a top view which shows the shape of the blank which comprises a paper cup. It is sectional drawing which represents typically the lamination sheet which makes a blank. It is a fragmentary sectional view showing the top curl processing process of the present invention.

Hereinafter, embodiments of the paper cup manufacturing of the present invention will be described in detail with reference to the drawings.
FIG. 4 shows a blank 100 comprising a fan-shaped body member 10 and a circular bottom member 20 constituting a paper cup.
Blanks used in the manufacture of these paper cups are composed of laminated sheets having a configuration as shown in FIG.
That is, the blank of the paper cup of this example is composed of a laminated sheet of a paper base material layer and at least an inner thermoplastic resin layer. For example, as shown in FIG. 5A, it is composed of a laminated sheet 200 in which a paper base material layer 101 and an inner thermoplastic resin layer 102 are laminated. Alternatively, as shown in FIG. 5B, it is composed of a laminated sheet 300 in which an outer thermoplastic resin layer 103, a paper base material layer 101, and an inner thermoplastic resin layer 102 are laminated.

Further, another layer may be provided between the outer thermoplastic resin layer 103 and the paper base material layer 101 or between the paper base material layer 101 and the inner thermoplastic resin layer 102. For example, an aluminum vapor deposition film can be provided between the outer thermoplastic resin layer 103 and the paper base material layer 101 in terms of design. In addition, by laminating metal foil such as aluminum foil, providing a vapor deposition layer such as silicon oxide, by laminating a barrier layer with high barrier properties such as saponified ethylene / vinyl acetate copolymer and polyamide film, Permeation of oxygen gas, moisture, fragrance, odor of outside air, etc. can be suppressed.
These are bonded by a dry laminating machine, a wet laminating machine, an extruder laminating machine or the like.

For the paper base material layer 101, a paperboard having a basis weight of 150 to 400 g / m ² , which is called a cup base paper, is preferably used. As the inner thermoplastic resin layer 102 and the outer thermoplastic resin layer 103, an ethylene-based thermoplastic resin such as low-density polyethylene or a polypropylene-based thermoplastic resin is used. The thickness of the inner thermoplastic resin layer 102 is preferably 20 to 60 μm, and the thickness of the outer thermoplastic resin layer 103 is preferably 10 to 40 μm.

In order to laminate the inner thermoplastic resin layer 102 and the outer thermoplastic resin layer 103 on the paper base material layer 101, an extrusion laminating machine is used. Immediately before the lamination, it is desirable that the surface of the paper base material layer 101 is subjected to an easy adhesion treatment such as a corona treatment.
If you want to thicken the inner thermoplastic resin layer 102, for example, when the paper base is thick and it is difficult to smooth the edges because of the edge treatment coming inward, sealant film manufactured in a separate process is sandwiched with molten resin May be laminated.

The body part bonding portion 11 provided at one end of the body member 10 is linearly provided on the side surface, and after being heated and edge protected, the whole is rounded, The body member 10 is preliminarily formed into a truncated cone side surface shape by being bonded to the inner surface of the end portion 111.
The bottom member 20 is preformed so that the peripheral edge portion 21 is squeezed by a press and bent downward.
In this way, the preformed body member 10 and the bottom member 20 are prepared, and they are inserted into a truncated cone-shaped mandrel so that the periphery 21 of the bottom member is covered with the lower part of the body member 10 and tightened. Thus, the bottom is molded.

Next, the top curl 3 is formed on the paper cup with the bottom formed.
As shown in FIG. 1-1, the top curl includes a top curl lower mold 4 that matches the shape of the entire lower part of the paper cup, and a top curl upper mold 5 that matches the shape near the opening of the paper cup.

  The top curl lower mold 4 has a shape in which the waist of the paper cup acts effectively and does not deform even when a paper cup is inserted and pressure is applied from above, and the shape below the top curl is formed at the upper tip. A lower mold groove 42 which is a concave portion is provided.

  The top curl upper die 5 is designed so that the tip matches the internal shape of the paper cup opening, and the material in the vicinity of the top curl portion does not escape inside, and the top curl is a recess having a shape above the top curl. A mold groove 52 is provided.

The top curl portion is formed by winding the upper end opening peripheral edge of the paper cup to which the body portion and the bottom portion are coupled while guiding the outer periphery along the curved groove portion provided on the top curl mold. Mold the top curl. (Figure 1-2)
The top curl mold is provided with a parting 50 between the top curl upper mold 5 and the top curl lower mold 4 immediately below the maximum outer diameter portion 32 of the top curl at the position of the top curl to be molded.
The length of the parting 50 is minimized, and a sliding surface 500 where the upper mold and the lower mold perpendicular to the parting surface are combined is provided on the outside thereof.

Further, in the parting 50 between the upper mold and the lower mold of the top curl mold, the upper mold end 51 on the product side to be molded is provided inside the lower mold end 41.
Further, the lower mold end 41 is provided with a curved surface.

The top curl processing steps are shown in FIGS. 6-1 and 6-2.
As shown in FIG. 6A, when the top curl lower mold 4 is raised, the top of the paper cup has a tip that hits the upper mold groove 52 and slides the surface of the upper mold groove 52 along its curved surface to open outward. To be spread.
Further, as shown in FIG. 6B, when the top curl lower mold 4 is continuously pushed up, the top of the paper cup is deformed while sliding along the curved surface of the upper mold groove 52, and gradually rounds.
In this process, when the top is rounded in the vicinity of the upper parting, the parting 50 is provided slightly below the maximum outer diameter portion 32 at the same time.
Therefore, in the vicinity of the parting 50 on the lower side from the maximum outer diameter portion 32, the top curl portion descends in a state where the applied pressure is eliminated so as to be separated from the upper mold end portion 51 on the product side. Moreover, since the upper mold end 51 is provided on the inner side of the lower mold end 41, the curled top does not contact the lower mold end 41, so that the top curl tip end side is not rubbed. It curls and there is no creaking or burring in the top curl.
Even if the curl of the top returns and extends somewhat, since the curved surface 44 is provided at the tip of the lower mold end 41, there is no fear of being cut off.

Moreover, the parting 50 is provided in the minimum length.
In addition, on the outside of the parting, there is provided a sliding surface 500 of a mold for fitting the upper mold and the lower mold perpendicular to the parting surface.
Accordingly, the sliding surface 500 is set at a position further away from the maximum outer diameter portion 32 of the top curl by the length of the parting 50.
For this reason, even if burrs or edges occur, there is no fear that they will turn up due to mold opening.
Ultimately, the tip end of the top curl is built into the top curl as shown in FIG.

The top-curled paper cup may be used as it is, but after filling the contents, a lid material having a sealant layer on the inner surface side is prepared in a separate step on the curled top curl part. Or is sealed.
The sealant layer of the lid is a film that can be easily fused and peeled off at low temperatures by mixing ethylene / vinyl acetate copolymer, elastomer / tackfire, etc. with olefin resin such as low density polyethylene. Manufactured in what

The mold used for the top curl of the paper cup according to the present invention is preferably manufactured by adjusting to a certain temperature.
The lower mold is manufactured using an aluminum alloy such as duralumin, an alloy tool steel such as brass, stainless steel, or pre-hardened. The surface of the mold may be provided with a crack and impregnated with a highly slidable fluororesin or the like.
The upper mold is manufactured from an aluminum alloy such as duralumin or a titanium alloy, and is often used as an ultrasonic horn attached to an ultrasonic machine.

The present invention is as described above, and the top curl mold of the paper cup according to the present invention hardly generates burrs, and even if burrs or protrusions are generated, they do not rise. Even if you touch the paper cup, you can produce a paper cup that can be used with peace of mind without causing injury or pain.
Thus, since a safe paper cup can be stably produced, the yield rate is high, and a paper cup can be manufactured at high speed, and the advantages of the present invention are great.

DESCRIPTION OF SYMBOLS 1 ...... trunk | drum 10 ...... trunk | drum member 11 ...... trunk | drum bonding part 12 ...... trunk | drum lower part folding | turning Part 13 ... Top curl part 131 ... Start winding line (top curl part)
100... Blank 101... Paper base material layer 102... Inner thermoplastic resin layer 103 .. Outer thermoplastic resin layer 111. ... End (the other end of the body part)
2 ..... Bottom part 20 ..... Bottom member 21 .....
200 ・ ・ ・ ・ ・ ・ ・ Laminated sheet (2 layers)
3 .... Top curl 31 ... Bali (top curl)
32 ... Maximum outer diameter (top curl)
300 ... Laminated sheet (3 layers)
4 ··························································· Lower mold end
42 ·········· Lower mold groove 44 ······ Curved surface (end of lower mold end)
5 ... Top curl upper mold 50 ... Parting 500 ... Sliding surface 51 ... Upper mold end ( Product side edge)
52 ... Upper mold groove

Claims (4)

The top of the paper cup that forms the top curl portion by winding it while guiding the periphery of the upper end opening of the paper cup to which the body portion and the bottom portion are joined along the curved groove provided on the top curl mold. In the mold for curl molding,
The groove portion is composed of an upper die and a lower die, and the curved groove portion is divided into an upper die groove portion and a lower die groove portion, and the upper die and the lower die are brought into close contact with each other so that the curved groove portion is formed. Configured to be formed,
A top curl molding die characterized in that a parting between an upper mold and a lower mold is provided immediately below the maximum outer diameter portion of the top curl at the position of the top curl to be molded.   The groove parting divided into the upper mold and the lower mold of the top curl mold is characterized in that the end of the upper mold on the product side is located inside the end of the lower mold. Top curl mold.   A sliding surface for aligning the upper mold and the lower mold perpendicular to the parting surface is provided outside the groove parting divided into the upper mold and the lower mold of the top curl mold. Item 3. The top curl mold according to Item 1 or 2.   The top curl mold according to any one of claims 1 to 3, wherein a curved surface is provided at the lower mold end of the product part in the parting of the upper mold and the lower mold of the top curl mold .

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