JPH0425308Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a device for attaching and joining a bottom such as an upper sole or a lower sole to a cylindrical cup body.
The present invention relates to a cup bottom attachment device for joining together a body and a bottom made of a laminate containing metal foil.

[Conventional technology]

Conventionally, it has been known to mold paper cups according to the procedure shown in FIG. That is, in FIG. 14, a blank 1 is formed by punching out a sheet material such as paper having a heat-bondable resin layer on both sides into a predetermined shape necessary for making the body of the cup, and this blank 1 is made into a cylindrical shape. Roll it up and partially overlap its edges on both sides, and the overlapped part (hereinafter referred to as the sealed part)
Hot air 2 is blown onto 1A to heat and melt the resin layer in this area, and the seal portion 1A is pressed and joined using a trowel (not shown) to form the cup body 3. On the other hand, a continuous strip 4 made of the same material as the blank 1
A bottom 6 is molded by punching out a disk 5 from the blank and raising the outer circumference of the disk 5 into a cylindrical shape. This bottom 6 is inserted into the body part 3, hot air 7 is blown onto the joint part to heat and melt the resin layer in this part, and then the tip of the body part 3 is turned inward using a curling mold (not shown). The bottom 6 and the body 3 are joined by bending the bottom 6 and placing it over the cylindrical portion of the bottom 6, and knurling the bent portion from the inner diameter side with a knurling 8. Finally, the end of the bottom 6 of the body 3 on the side opposite to the attachment side is curled. The cup 9 is molded by the above operations.

[Problem that the invention attempts to solve]

However, in this conventional cup forming method, hot air is used for heating and joining the bottom 6 inserted into the body 3, resulting in the following problems.
That is, since the paper cups manufactured are usually used for food, the air used must be highly purified, and the equipment for this purpose is expensive. In addition, since the joints of the body and bottom are heated with hot air, the thermal efficiency is extremely low, consuming a much larger amount of heat than is required to actually heat and melt the resin on the sealing surface, and the machine Even when the machine is temporarily stopped, such as during adjustment, it is necessary to blow out hot air at appropriate intervals to prevent the heater of the hot air generator from breaking due to overheating, which results in a lot of energy waste. Furthermore, since such paper cup manufacturing equipment is generally installed in a highly airtight clean room, problems such as an increase in indoor temperature in the summer due to a large amount of hot air and an increase in cooling power costs arise due to this. Furthermore, due to malfunctions or problems with the solenoid valves that turn hot air on and off, hot air could not be blown out, and cups with leaking seals were sometimes mixed in.

The present invention was devised in view of these conventional problems, and provides a cup bottom attachment device that can quickly heat and join the joint between the body and the bottom while reducing energy costs. The purpose is to provide.

[Means for solving problems]

In order to achieve the above object, the inventor of the present invention, after various studies, focused on the metal foil layer included in the laminate that constitutes the body and the bottom, and by generating an induced current in the metal foil, They discovered that it is possible to generate heat directly and use this heat to heat and melt the resin layer to quickly and reliably seal, and have completed the present invention.

That is, the present invention includes a mandrel that holds the cup body into which the bottom has been inserted, and a heating device that heats the tip of the cup body held by the mandrel by high-frequency induction, and the heating device includes a concentric heating coil;
a moving device for moving the heating coil to an operating position located inside and outside the tip of the cup body held on a mandrel and a standby position distant from the tip of the cup body; and a high-frequency power source device for applying a high-frequency voltage to the heating coil. The subject matter is a cup bottom attachment device characterized by having:

[Effect]

In the above device, by placing a bottom of a predetermined shape on one end of the mandrel and attaching the body of the cup to the mandrel from above, the bottom is inserted into a predetermined position near the tip of the body. Next, a concentric heating coil is brought close to the tip of the body attached to the mandrel, and the inner heating coil is positioned inside the body and the outer heating coil is positioned outside the body. When a high-frequency voltage is applied to both heating coils, a high-frequency current flows through the inner and outer heating coils, and the magnetic field in and around the area sandwiched between the inner and outer heating coils changes, and the body and An induced current is generated in the conductive portion of the bottom, that is, the metal foil, in a direction that prevents the change in the magnetic field, and heat is generated. This heat generation heats and melts the resin at the joint surface between the body and the bottom.
Therefore, by applying an appropriate pressing force to the heated joint surfaces, the body and the bottom can be fused and joined.

〔Example〕

Embodiments of the present invention shown in the drawings will be described below.
FIG. 1 is a schematic plan view showing a cup forming apparatus equipped with a bottom attachment device according to an embodiment of the present invention. In the same figure, 11 is a blank supply device that supplies a blank 12 of a predetermined shape, 13 is a body forming device that winds the supplied blank 12 into a cylindrical shape to form a body, and 14 is a body forming device that supplies a blank 12 having a predetermined shape. 15 is a strip supply device that supplies a strip 16 for forming the bottom to a predetermined position; 17 is a strip supply device that punches out the strip 16 to form the bottom, and also uses this bottom as the body. 18 is a curling device that curls one end of the body to which the bottom is attached; 19 is a cup take-out device that takes out the finished cup.

The body forming device 13 includes a turret 22 equipped with a large number (eight in the illustrated embodiment) of spindles 21 extending in the radial direction, and a drive device (not shown) that intermittently rotates the turret 22 one pitch at a time in the direction shown by the arrow. ). For convenience, as shown in FIG. 2, the stop position of the spindle 21 is set to P1.
- Shown as P8. FIG. 2 is a perspective view showing the spindle 21 located at position P2 and its surroundings. In FIG. 2, the spindle 21 is rotatably held by a turret 22, and a drive device for rotating the spindle 21 about its central axis is provided inside. The spindle 21 has a conical shape that matches the shape of the cup to be molded, and is provided with a flat surface 24 having a number of holes 23 on a part of its outer circumferential surface. The numerous holes 23 are for suctioning and holding the blank against the flat surface 24, and a cavity is formed in the spindle 21 which is communicated with a vacuum suction source. Furthermore, a blank holder 26 is provided near the spindle 21 and substantially parallel to it. Blank presser foot 26
is held by a bracket 27 fixed to the turret 22.

A pressing member 30 is provided above the spindle 21 at position P2. This pressing member 30
is fixed to a holding member 31, and the holding member 31 is attached to a lifting device 32 by a pin 33. Thus, the lifting device 32 allows the pressing member 30 to be moved to a position where it contacts the spindle 21 and to a position where it is away from the spindle 21, and when the pressing member 30 is lowered, its lower surface is evenly pressed against the flat surface 24 of the spindle 21. can be The pressing member 30 is made of a non-conductive material such as Bakelite or resin, and as shown in FIGS. 6 and 7, a high frequency heating coil 35 is disposed inside. A high frequency power source is connected to this high frequency heating coil 35, and the coil 35 is configured to allow cooling water to pass therethrough. The shape of the heating coil 35 is such that it substantially surrounds the overlapping portion of the blanks 12, that is, the seal portion. Note that although the drawing shows a structure in which the heating coil 35 is integrally embedded within the pressing member 30, the structure is not limited to this, and the pressing member 30 may have a recess and the heating coil 35 can be removed from the recess. It is also possible to have a structure in which it is held in place. As shown in FIG.
It is formed flat so that it can be pressed uniformly against the flat surface 24 of. This lower surface is preferably made of a releasable material so that the resin on the surface of the blank 12 does not adhere when the seal portion is sealed. As the material for the lower surface of the pressing member 30, Teflon is suitable. Note that a releasable sheet may be removably provided on the lower surface of the pressing member 30, and only the sheet may be replaced when this sheet wears out.

The above-mentioned pressing member 30 and its related members may be provided not only at the position P2 but also at adjacent positions P3, P4, etc., if necessary.

In FIG. 1, the bottom mounting device 17 is an embodiment of the present invention, and includes a turret 41 holding a number of mandrels 40 upright at the same radial position from the center at a constant pitch, and the turret 4.
1 is provided with a drive device (not shown) that intermittently rotates one pitch at a time. For convenience, as shown in FIG. 1, the stopping positions of the mandrel 40 are indicated as Q1 to Q8. As shown in FIGS. 8 and 9, the mandrel 40 has a conical shape that fits the body 46 molded by the body molding device 13. Position Q4,
As shown in FIG.
5 is provided. This heating coil 44, 45
is held movably up and down by a moving device (not shown), and as shown in FIG.
It is movable between a standby position upwardly away from the tip of the body 46 held in the body and an operating position shown in FIG. The heating coils 44, 45 are dimensioned so that, when lowered to the operating position shown in FIG. 10, they are located inside and outside the upper end of the body 46 held on the mandrel 40. These heating coils 44 and 45 are also connected to a high frequency power source (not shown) and are configured to allow cooling water to pass through them. In Fig. 1, various devices such as a curling device and a knurling device are provided at positions other than positions Q4 and Q5, but since these are well-known devices, a detailed explanation will be omitted and the explanation will be omitted. Only the operation will be described later. In addition, since the other devices constituting the cup forming device shown in FIG. 1 are well known, a description of their structure will be omitted.
Only its operation will be described later.

Next, the cup forming operation by the cup forming apparatus described above will be explained.

Blank 12 and strip material 16 used in this example
A laminate having at least metal foil, for example aluminum foil, and a thermoplastic resin layer on one side is used. Examples of this laminate include, for example, PE/
A/Paper/PE, PE/A/Paper/A/PE,
There are paper/A/PE, etc., and synthetic paper, resin sheet, etc. may be used instead of paper in these laminates, and PP, EVA, etc. may be used instead of PE on the surface. The strip 16 is usually the same material as the blank 12, but it is also possible to use a material that does not contain metal foil.

In FIG. 1, a blank assembly 12A in which a large number of blanks cut into predetermined dimensions are stacked is set in a blank supply device 11. As shown in FIG. Blanks 12 are taken out one after another from this blank collection No. 12A, turned over midway, and placed at a position P of the body forming device 13.
1. At position P1, as shown in FIG. 3, one end of the blank 12 is aligned with the flat surface 24 of the spindle 21, and by applying a vacuum to the cavity within the spindle 21, one end of the blank 12 is suctioned and held against the flat surface 24. be done. In this state, the spindle 21 rotates in the direction of the arrow and the blank 12 is wound around the outer peripheral surface of the spindle 21. spindle 21
Both ends of the blank 12 wound around the outer peripheral surface of the blank 12 are overlapped at a flat surface 24, and the outer portion is restrained by a blank presser 26. In this state, the turret 22 rotates one pitch, and the spindle 21 around which the blank 12 is wound moves to position P2. The state at this time is the state shown in FIG. At this time, the pressing member 30 is waiting upward.

Next, as shown in FIG. 5, the lifting member 32 lowers the pressing member 30 and presses the overlapping seal portions of both side edges of the blank 12 wound around the outer peripheral surface of the spindle 21 against the flat surface 24 of the spindle 21. (See Figure 6). During this descent, the pressing member 30
Application of high frequency voltage to the heating coil 35 is started. As a result, while the pressing member 30 descends and presses the subsequent seal portion,
A high-frequency current flows through the heating coil 35, and an induced current is generated in the metal foil in the blank 12 in the portion surrounded by the heating coil 35 and in the vicinity thereof, generating heat.
Due to this heat generation, the resin layers on the sealing surfaces of the overlapping blanks are heated and melted, and are bonded to each other. After passing a high-frequency current through the heating coil 35 for the time necessary to heat and melt the resin layer on the sealing surface, first the heating coil 3 is turned on while the pressing member 30 is pressed against the blank 12.
Cut the current to 5. As a result, heat generation is stopped, so that the heat of the molten resin portion of the sealing surface flows reversely to the pressing member 30, in other words, the sealing surface is cooled.
After that, the pressing member 30 is raised and the blank 12
Open the seal part. At this time, the sealing surfaces have already been bonded and cooled, so the blank 12
Even if there is a restoring force, the sealing surface will not peel off. Through the above operations, the seal portions on both side edges of the blank 12 are joined, and the cylindrical body portion 46 is formed.

In this sealing operation, the metal foil inside the blank is usually about 6μ to 25μ, and in order to cause an induced current to flow through such a thin metal foil to generate heat, the frequency applied to the heating coil 35 must be 100KHz to 2M.
Hz is preferred. In addition, in this joining, the seal portion is heated while being pressed by the spindle 21 and the pressing member 30, so if the application time of the high frequency voltage to the heating coil 35 and the pressing conditions by the pressing member 30 are appropriately set. , not only the sealing surfaces are melted and bonded, but also, as shown in Fig. 13,
Resin layer 1 on both sides of non-resin layer 12A of blank 12
The resin 2B flows laterally to cover the end face of the non-resin layer 12A, thereby preventing the contents of the paper cup from permeating through this end face. When an induced current is caused to flow through the metal foil in the blank 12, it is preferable to prevent the induced current from flowing through the spindle 21 as much as possible in terms of energy consumption and prevention of overheating of the spindle. It is preferable to use one that generates high magnetic flux density.
As such a heating coil 35, it is preferable to use a small-diameter wire (for example, about 3 mm in diameter) as the wire constituting the coil. If a large amount of heat is generated in the spindle 21 or the blank holder 26 due to an induced current, the material of the spindle 21 or the blank holder 26 may be replaced with a non-conductive material.

Note that the application of the high-frequency voltage to the heating coil 35 may be started after the pressing member 30 contacts the blank 12, but as explained above, if the pressing member 30 is being lowered, On the other hand, it becomes possible to lengthen the heating time, which is preferable.

In FIG. 1, if a pressing member similar to that at position P2 is also provided at position P3, position P2
The sealed portions of the blanks 12 that have been joined are again pressed together using a pressing member and heated and joined by high-frequency induction heating. In this way, not only position P2 but also position P
If a pressing member equipped with a heating coil is also provided in 3, it becomes possible to shorten the heating time at each position, and it is possible to shorten the period of intermittent rotation of the turret 22 and increase productivity. Become.

In this embodiment, the pressing member 30 equipped with a heating coil 35 is provided to move up and down at a fixed position, for example, position P2 or P3, but instead of this, a heating coil is provided corresponding to each spindle 21. A pressing member may be provided, and this pressing member may be held by the turret 22 so as to rotate intermittently or continuously together with the spindle 21. In this case, even while the spindle is moving from one position to the next due to rotation of the turret, it is possible to press the pressing member against the blank on the spindle and continue heating, thereby reducing the necessary heating time. It becomes possible to further shorten the cup molding cycle while ensuring the same.

Referring again to FIG. 1, the body formed by being wrapped around the outer peripheral surface of the spindle 21 and having its both side edges joined is moved to position P by the rotation of the turret 22.
7 and transfer device 1 at position P7.
4 from the spindle 21 and fed to the bottom mounting device 17.

On the other hand, the bottom attachment device 1 is
The strip material 16 supplied at point 7 is supplied onto the mandrel 40 at position Q1, where it is punched out into a disk shape, its outer periphery raised into a cylindrical shape, and formed into a bottom 47 as shown in FIG. be done. When the mandrel 40 carrying this bottom 47 moves to position Q3, the 8th
As shown in the figure, the body 46 is lowered from above by the transfer device 14, and the bottom 47 is inserted into the body 46 as shown in FIG. Next, at positions Q4 and Q5, the heating coils 44 and 45 descend from above the mandrel 40 and are located inside and outside the upper end of the body 46, as shown in FIG. By passing a high frequency current through these heating coils 44 and 45, the inner and outer heating coils 4
The magnetic field between 4 and 45 changes, and an induced current is generated in the metal foil of the body 46 and bottom 47 located between them, generating heat and heating and melting the resin layer in the vicinity.
The frequency of the high frequency power source used here is preferably the same as that applied to the heating coil 35 described above. After an appropriate period of time has elapsed, the heating coils 44, 45 are retracted upward. The application start and stop times of the high-frequency voltage to the heating coils 44 and 45 are not particularly limited, and may be continuous, or may be interrupted at appropriate timings when the heating coils are lowered or raised. Even if a high-frequency current is passed through the heating coils 44 and 45 located away from the body 46, if there is no conductive material that generates an induced current in the vicinity, the current will not flow much and the energy loss will not be so large. . Next, the mandrel 40 moves to position Q6, and at that position, the curling mold 48 descends as shown in FIG.
Fold the tip inward. Thereafter, after the curling mold 48 is retracted upward, the mandrel 40 moves to position Q7, and at that position, as shown in FIG. The knurling 51 is the body part 46
It rotates while pressing against the inner surface of the knurling hole 52 located on the outside. As a result, the cylindrical portion of the bottom 47 is inserted into the tip of the body portion 46 and joined.

In the above explanation, concentric heating coils 44 and 45 are provided at two positions Q4 and Q5, respectively, and high-frequency induction heating is performed twice on the same trunk and bottom, but with one heating If the temperature can be raised to the temperature required for bonding, one of the heating coils may be omitted; on the other hand, if the heating is insufficient, the number of heating coils may be further increased. Also,
In the case of increasing the number of heating coils, the heating coils may be incorporated into the curling mold 48 shown in FIG. 11. However, in that case, due to space limitations, even if a concentric heating coil is incorporated into the curling mold 48, it may not be possible to lower the heating coil to the position shown in FIG. High-frequency induction heating is still possible, although the heating efficiency will be lower. Furthermore, if it is difficult to incorporate concentric heating coils into the curling mold 48, only the outer heating coil 44 may be incorporated. Even with this configuration, high-frequency induction heating of the tip of the body is possible.

The body 46 with the bottom 47 attached is transferred from position Q8 in FIG. 1 to the curling device 18, where the end opposite to the bottom 47 is curled to complete the cup. The completed cups are taken out one after another by the take-out device 19 and stacked on top of each other.
Once a cup assembly is formed by stacking a certain amount of cups, it is delivered to a predetermined position.

In the above embodiment, when joining the bottom 47 to the body 46, the tip of the body is folded inward, and the bottom 47 is attached to the body 46.
However, folding the tip of the body inward is not necessarily essential to the present invention, and the bottom 47 is simply inserted into the body 46, and in that state, the inner surface of the body is inserted. The joint surface between the bottom outer surface and the bottom outer surface may be joined. In addition, although the above embodiment incorporates the bottom attachment device of the present invention into a series of cup forming devices, the present invention is not limited to this case, and can be applied to a device that simply joins the bottom to the body. It goes without saying that it is okay to do so.

Embodiment In the apparatus shown in FIG.
Heating coils 44 and 45 were placed at mandrel stopping positions Q4 and Q5 of No.7. Cup molding was carried out using this apparatus under the following conditions.

Materials used Blank 12 PE 20μ (outside of container) Aluminum 7μ PE 18μ Paper 300g/m ² PE 40μ (inside container) Band material 16 PE 20μ Aluminum 15μ PE 18μ Paper 300g/m ² PE 40μ Production volume 120 pieces/min (turret 22 , 41 intermittent rotation period 0.5 seconds) Body sealing conditions Heating time by heating coil 35 0.2 seconds Application frequency to heating coil 35 210KHz Bottom sealing conditions Heating time by heating coils 44, 45 0.2 seconds Application frequency to heating coils 44, 45
250KHz As a result of cup molding under the above operating conditions, it was possible to obtain a cup in which the seal portion was well bonded. Also, put 0.3% soapy water in this cup,
As a result of a 10 minute leak test, no leakage occurred.

[Effect of idea]

As is clear from the above description, the bottom attachment device of the present invention includes a mandrel that holds the cup body into which the bottom has been inserted, and a heating device that heats the tip of the cup body held by the mandrel by high-frequency induction. , the heating device includes a concentric heating coil, and a moving device for moving the heating coil between an operating position located inside and outside of the tip of the cup body held on a mandrel and a standby position away from the tip of the cup body; Since the heating coil is characterized by having a high frequency power supply device that applies a high frequency voltage to the heating coil, the bottom can be placed on one end of the mandrel and the body can be placed over the body to insert the bottom into the body at a predetermined position. The concentric heating coil is placed close to the tip of the body attached to the mandrel, the inner heating coil is located inside the body, the outer heating coil is located outside the body, and both heating coils are placed close to each other. By applying a high-frequency voltage to the coil, an induced current flows through the conductive parts of the body and bottom, that is, the metal foil, located in the area sandwiched between the inner and outer heating coils and the vicinity thereof, causing heat generation, which causes the resin on the joint surface to heat up. can be joined by heating and melting. In this way, the present invention uses induction heating to heat the joints, making it possible to heat only the necessary areas when heating is required, which reduces energy consumption compared to conventional methods that use hot air. In addition, heating can be interrupted and interrupted by high-frequency power supply, and this intermittence can be activated by a non-contact signal from this machine (cup molding machine). Since there is no need to use a solenoid valve as in the case of hot air,
It has various effects such as eliminating problems such as seal failure due to malfunction of the solenoid valve.

[Brief explanation of the drawing]

FIG. 1 is a plan view schematically showing the entire cup molding device equipped with a bottom attachment device according to an embodiment of the present invention, FIG. 2 is a perspective view of a main part of the body portion molding device of the cup molding device, and FIG. 4, and 5 are perspective views of essential parts for explaining the operation of the body molding device, respectively, and FIG. 6 shows the spindle 2 in the state shown in FIG.
1. A cross-sectional view of the pressing member 30, etc.; FIG. 7 is a cross-sectional view of the pressing member 30 when viewed in the negative direction in FIG.
9 is a perspective view of a main part explaining the operation of the bottom attachment device according to the embodiment of the present invention provided in the cup forming apparatus, and FIG. 10, FIG. 11, and FIG. 12 are operation of the bottom attachment device. FIG. 13 is an enlarged cross-sectional view showing a portion joined by the body molding device, and FIG. 14 is a perspective view showing a conventional cup molding procedure. 11... Blank supply device, 12... Blank, 13... Body forming device, 17... Bottom mounting device, 40... Mandrel, 41... Turret,
44, 45... Heating coil, 46... Body, 47
... Bottom, 48 ... Curling mold, 50 ... Knurling device, 51 ... Knurling.

Claims (1)

[Scope of utility model registration request] It is equipped with a mandrel that holds the cup body into which the bottom has been inserted, and a heating device that heats the tip of the cup body held on the mandrel by high-frequency induction, and the heating device includes a concentric heating coil and a heating coil that is connected to the mandrel. The heating coil is characterized by having a moving device that moves the cup to an operating position located inside and outside of the tip of the cup body held in the cup body and a standby position located away from the tip of the cup body, and a high frequency power supply device that applies a high frequency voltage to the heating coil. A device for attaching the bottom of the cup.