JP4835092B2 - Container heat sealing method and apparatus - Google Patents

Description

  The present invention relates to a container heat-sealing method and apparatus, and is capable of heat-sealing at high speed and stably when a film-like lid material is heat-sealed on a container body such as a cup of paper or synthetic resin. is there.

  Containers such as paper and synthetic resin cups that are sealed by heat-sealing film-like lids are widely used as food containers such as jelly, baby food, soup and miso. Used as a container for food and cooked foods.

  In such a container, heat sealing is generally performed in which the container main body and the lid member are sealed by heating using a seal head.

  As such a heat sealing method, in Patent Document 1, the lid is transported by the lid holding and transporting means disposed above the container transporting means and is put on the container, and the state in which the container and the lid are kept in close contact with each other is maintained. However, induction heating is performed by a high-frequency seal head arranged in a non-contact state above the lid so that the seal head or the container itself can be sealed at high speed without moving up and down.

  Further, in Patent Document 2, the lid material and the container are bonded at high speed by using heating by the heater cartridge and high-frequency dielectric heating or ultrasonic vibration heating in combination.

Further, in Patent Document 3, as shown in FIG. 4, a heating presser belt 4 in which a metal body 2 is sandwiched with a heat-resistant elastic material 3 so as to move synchronously and parallel above the container conveyor belt conveyor 1 is provided. A high-frequency induction heating coil 5 is disposed on the cover 6 for high-frequency induction heating to seal the lid 7 placed on the container 6.
JP 2004-250027 A Japanese Patent Laid-Open No. 11-20801 Japanese Patent Publication No.58-19536

  When trying to seal at high speed by such a heat sealing method, when the seal head is pressed against the lid and heated in a circumferential shape, if the volume (heat capacity) of the heat transfer part of the seal head is small, the temperature of the seal head during sealing It is necessary to make the seal head large in volume and heat capacity.

  However, when trying to seal at a high temperature using a large sealing head, not only the periphery of the lid but also the central part is heated, the temperature tends to rise, and the gas in the head space of the container expands at the stage where the welded part does not completely adhere. There is a problem that the lid member cannot be sealed due to wrinkles.

  Further, if the temperature of the seal head is raised and sealing is performed at a high speed (short time), the lid material is welded to the seal head, and sealing may not be possible, and there is a problem that the material of the lid material is limited.

  Furthermore, in the case of Patent Document 1 in which the lid material is heated by high-frequency induction heating, there is a problem that heating and sealing can be performed only when the lid material is made of metal.

  Furthermore, in any case of Patent Documents 1 to 3, since the entire surface of the lid member is heated, there is a problem that the gas in the head space of the container expands, thereby impairing the sealing performance.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a container heat-sealing method and apparatus capable of stably sealing at high speed regardless of the material of the lid. .

In order to solve the above-described problems of the prior art, the container heat-sealing method according to claim 1 of the present invention is the method of heat-sealing and sealing a lid material to a flange portion provided in an opening of the container. The sealing head formed in the shape of the flange portion is induction-heated at high frequency, and while the heated sealing head is pressed , a cooling medium is supplied into the shield head to weld the lid, and then the cooling medium The present invention is characterized in that compressed air having a smaller heat capacity is supplied to discharge and collect the cooling medium and replace it with air .

According to this container heat-sealing method, when the lid member is thermally welded and sealed to the flange portion provided in the opening of the container, the seal head formed in the shape of the flange portion of the container is subjected to high-frequency induction heating. While the heated seal head is pressed , a cooling medium is supplied into the shield head to weld the lid, and then compressed air having a smaller heat capacity than the cooling medium is supplied to discharge the cooling medium. It is designed to recover and replace with air, and by using a seal head with the shape necessary for sealing the lid, it can be stably sealed at high speed while suppressing the effects of temperature drop and head space gas expansion. I am doing so.
In addition, the shield head is cooled while the seal head is heated and pressed. Even when the seal temperature is increased, the seal head is cooled and finished pressing, thereby preventing the cover material from sticking to the seal head. And can be sealed more quickly and stably.
Furthermore, cooling of the seal head is performed by supplying compressed air having a heat capacity smaller than that of the cooling medium into the seal head to discharge and collect the cooling medium and replace it with air. In addition to being able to be performed, it is possible to shorten the heating time by replacing with air having a smaller heat capacity than the cooling medium, and to increase the speed of heat sealing.

The container heat seal apparatus according to claim 2 of the present invention is a container heat seal apparatus provided with a seal head that heat seals and seals a lid member on a flange portion provided in an opening of the container. A heat welding member provided in the shape of the flange portion provided in the seal head main body, a high frequency induction heating coil provided in the seal head main body for high frequency induction heating of the heat welding member, and a lid provided in the heat welding member A cooling medium flow path that can be cooled while being pressed against the material, and after cooling the lid material provided on the heat welding member, compressed air having a smaller heat capacity than the cooling medium is supplied to discharge and collect the cooling medium in the cooling medium flow path And a cooling medium discharging means that can replace the air .

According to the heat seal apparatus for a container, the heat seal apparatus for a container includes a seal head that seals by sealing a lid material to a flange portion provided in an opening of the container, and is provided in the seal head main body. The heat welding member formed in the shape of the flange portion, a high frequency induction heating coil provided in the seal head body for high frequency induction heating of the heat welding member, and a cooling material provided on the heat welding member while being pressed against the lid member are cooled. Cooling medium flow path to be obtained, and cooling that is provided on the heat-welding member and that can cool and replace the cooling medium in the cooling medium flow path by supplying compressed air having a smaller heat capacity than the cooling medium after cooling the lid member It includes a medium discharging unit, and by heating the thermal welding member flange shaped high-frequency induction heating coil can heat the heat seal member to the temperature required sealing in a short period of time, lid member In sealing head shape required for sealing, it becomes possible to stably seal at high speed while suppressing the influence of the expansion of the gas temperature drop and headspace.
Furthermore, the heat-welding member is provided with a cooling medium flow path that can be cooled while being pressed against the lid, and by easily cooling the seal head, the seal head is cooled and pressed even when the seal temperature is increased. By finishing, it is possible to prevent the cover material from sticking to the seal head, and to seal more stably at a higher speed.
In addition, a cooling medium discharge means is provided that is provided on the heat welding member and supplies the compressed air having a heat capacity smaller than that of the cooling medium after cooling the lid member to discharge and collect the cooling medium in the cooling medium flow path and replace it with air. The heating time can be reduced by replacing the air with a smaller heat capacity as compared with the cooling medium while enabling the heating for the sealing of the next lid material to be performed in a shorter time, enabling high-speed and stable sealing. This makes it possible to shorten the heat sealing speed.

According to a third aspect of the present invention, in addition to the configuration of the second aspect , the container heat-sealing device includes a non-welding member coated on the pressing surface of the heat-welding member with the lid member. It is a feature.

  According to this container heat-sealing device, the non-welding member is coated on the pressing surface of the heat-welding member with the lid material, and the lid material sticks to the seal head even when the sealing temperature is increased. Can be prevented, and the sealing can be performed at higher speed and more stably.

According to a fourth aspect of the present invention, in addition to the constitution of the second or third aspect , the container heat seal device is provided with a temperature holding means capable of holding the heating temperature of the heat welding member in the seal head body. It is characterized by that.

  According to this container heat-sealing device, the sealing head main body is provided with a temperature holding means capable of holding the heating temperature of the heat-welding member, and the temperature is maintained up to a temperature that becomes a reference temperature range for heating and cooling. By holding by means, even if heating and cooling are repeated, it becomes possible to perform high-speed and stable sealing in a shorter time.

According to the container heat-sealing method of the first aspect of the present invention, when the lid member is thermally welded and sealed to the flange portion provided in the opening of the container, the container is formed in the shape of the flange portion of the container. The sealing head is heated by high frequency induction, and while the heated sealing head is pressed , a cooling medium is supplied into the shielding head to weld the lid, and then compressed air having a smaller heat capacity than the cooling medium is used. Supplying and recovering the cooling medium and replacing it with air, so using a seal head with the shape necessary for sealing the lid material, suppresses the effects of temperature drop and head space gas expansion. This makes it possible to stably seal at high speed.
In addition, since the shield head is cooled while the seal head is heated and pressed, the seal head can be cooled and finished even when the seal temperature is increased. The sticking can be prevented, and the sealing can be performed more quickly and stably.
Furthermore, the cooling of the seal head is facilitated by supplying compressed air having a smaller heat capacity than the cooling medium to discharge and collect the cooling medium and replacing it with air. This makes it possible to seal more quickly and stably, and by replacing the air with a smaller heat capacity compared to the cooling medium, it is possible to shorten the heating time, and the heat sealing speed is high. Can be achieved.

According to the container heat-sealing device according to claim 2 of the present invention, the container heat-sealing device includes a seal head that heat-seals and seals the lid material on the flange portion provided in the opening of the container. A heat welding member provided in a seal head body and formed in the shape of the flange, a high frequency induction heating coil provided in the seal head body for high frequency induction heating the heat welding member, and provided in the heat welding member. A cooling medium flow path that can be cooled while being pressed against the lid member, and after cooling the lid member provided on the heat welding member, compressed air having a smaller heat capacity than the cooling medium is supplied to cool the cooling medium in the cooling medium flow path. a coolant discharge means which can replace the discharge collected air is provided with the, by heating the thermal welding member flange shaped high-frequency induction heating coil, the shape required to seal the lid Ruheddo can be heated to the temperature required in a short time to seal, thereby, it is possible to stably seal at high speed while suppressing the influence of the expansion of the gas temperature drop and headspace.
Furthermore, since the cooling medium flow path that can be cooled while being pressed against the lid member is provided on the heat-welded member, the seal head can be easily cooled, thereby cooling the seal head even when the seal temperature is increased. By finishing the pressing, it is possible to prevent the cover material from sticking to the seal head, and it is possible to seal more stably at a higher speed.
In addition, the cooling member discharging means that supplies compressed air having a heat capacity smaller than that of the cooling medium after cooling the cover material to discharge and collect the cooling medium in the cooling medium flow path and replaces it with air is provided on the heat welding member. The heating for the sealing of the next lid can be performed in a shorter time, can be sealed at high speed and stably, and is replaced with air having a smaller heat capacity than the cooling medium, so that the heating time It is possible to shorten the heat sealing speed.

According to the container heat-sealing device of the third aspect of the present invention, the non-welding member is coated on the pressing surface of the heat-welding member with the lid member, so that the sealing head can be covered even if the sealing temperature is increased. It is possible to prevent the cover material from sticking to the seal head, and it is possible to seal more stably at higher speed.

According to the heat sealing apparatus for a container according to claim 4 of the present invention, since the temperature holding means capable of holding the heating temperature of the heat welding member is provided in the seal head main body, the reference of the temperature range for heating and cooling is provided. The temperature holding means can hold the temperature up to the above temperature, and even if heating and cooling are repeated, it can be stably sealed at a higher speed in a shorter time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 relate to an embodiment of a heat sealing method and apparatus for a container according to the present invention, FIG. 1 is an exploded view showing the container, and FIG. 2 relates to an embodiment of a heat sealing apparatus. It is a longitudinal cross-sectional view.

    In this container heat-sealing device (hereinafter simply referred to as a heat-sealing device) 20, for example, as shown in FIG. 1, the container 10 is composed of a container body 11 and a lid member 12 that covers the container body 11. The container body 11 is formed in a cup shape, and a flange portion 11a is formed around the upper end opening so as to project horizontally outward. On the other hand, the cover member 12 has a heat seal portion 12a extending horizontally corresponding to the flange portion 11a on the outer peripheral portion thereof, and a drop cover that protrudes downward and is located inside the annular heat seal portion 12a. The part 12b is integrally formed. The lid member 12 may have a flat plate shape including a normal heat seal portion 12a and a shape without a lid portion.

  A heat seal device 20 that heat-seals the container body 11 and the lid member 12 of the container 10 includes a seal head 21 as shown in FIG.

  The seal head main body 22 constituting the seal head 21 has the same shape corresponding to the shape of the heat seal portion 12a of the lid member 12, for example, a hollow ring shape, and is attached so that the lower surface of the heat welding member 23 is exposed. is there. The hollow portion 23a of the heat welding member 23 is used as a flow path of a cooling medium, for example, cooling water, and a cooling medium pipe 24 is connected to supply / discharge the cooling medium.

  Such a heat welding member 23 is formed of a material that can be heated by high frequency induction heating, and is made of metal, for example.

  In addition, a high frequency heating coil 25 is disposed above the heat welding member 23 of the seal head main body 22 of the seal head 21 and is configured as, for example, three turns on a horizontal plane parallel to the upper surface of the heat welding member 23. The power supply member (feeder) 26 is connected to a high-frequency power source. The high-frequency heating coil 25 is also hollow, so that a cooling medium, for example, cooling water can be supplied and discharged through the cooling medium pipe 27.

  A ferromagnetic body 28 is mounted in the seal head main body 22 so as to surround the heat welding member 23 and the high-frequency heating coil 25 to constitute a seal head 21, and the seal head 21 has a lifting / lowering pressing mechanism (not shown). It can be moved up and down and pressed.

  In this heat seal device 20, a container support member 29 is provided below the seal head 21, and supports the lower surface of the flange portion 11 a of the container body 11 of the container 10.

  Then, the container body 11 supported by the container support member 29 and covered with the contents is covered with the lid member 12, and the flange part 11 a of the container body 11 and the heat seal part 12 a of the lid member 12 are overlapped, and then the container The support member 29 and the seal head 21 can be pressed.

  Next, the heat sealing method of a container is demonstrated with the operation | movement of the heat sealing apparatus 20 comprised in this way.

  Usually, such a heat seal device 20 is provided in the filling line of the container 10 and is used for high-speed continuous production in which the contents are filled in the container main body 11 and then sealed by covering with a lid 12 and heat-sealing. Here, the heat sealing of a single container will be described as an example.

  After the container main body 11 with the flange portion 11a supported by the container support member 29 is filled with the contents, the container main body 11 is covered with the lid member 12 and the flange portion 11a of the container main body 11 and the heat seal portion of the lid member 12 are covered. 12a is overlaid, and the lid 12b of the lid 12 is mounted so as to protrude into the head space of the container body 11. In addition, in the case of a shape having no flat plate-shaped drop lid portion as the lid member, the flange portion 11a of the container body 11 and the heat seal portion 12a of the lid member 12 are covered so as to overlap each other.

  In parallel with the mounting of the lid member 12, the seal head 21 heats the surface of the heat welding member 23 by flowing a high-frequency current from a high-frequency power source to the high-frequency heating coil 25 via the power supply member 26. The heating by the high-frequency heating coil 25 is by high-frequency induction heating, and the high-frequency magnetic flux generated by the high-frequency current penetrates the heat welding member 23 that is the object to be heated and induces a very high density eddy current. The surface of the welding member 23 is heated.

  The heating temperature of the seal head 21 may be any temperature as long as the container main body 11 and the lid member 12 constituting the container 10 to be welded by heat sealing can be welded and sealed, and may be appropriately determined depending on the material of the container main body 11 and the lid member 12. The temperature is controlled by determining. In addition, normally, it is set as temperature required for heat sealing, for example, 200-220 degreeC.

  The sealing head 21 thus heated to the temperature necessary for heat sealing is supported by the container support member 29 via a lifting / lowering pressing mechanism (not shown), and the lid member 12 is applied to the flange portion 11a of the container body 11 covered with the lid member 12. The heat seal part 12a is sandwiched and pressed.

  Then, since the heated heat welding member 23 of the seal head 21 is formed in the same shape corresponding to the shapes of the flange portion 11a and the heat seal portion 12a, only the portion necessary for heat sealing is heated and pressed. Then, heat sealing is performed at a predetermined temperature.

  The heating by the seal head 21 does not directly heat the center portion (drop lid portion 12b) of the lid member 12 due to the shape of the heat welding member 23 and the shape including the drop lid portion 12b of the lid member 12, and the flange portion 11a and By directly heating only the heat seal portion 12a, the expansion of the gas in the head space of the container body 11 can be suppressed as much as possible even if heat sealing is performed at a high temperature, and the influence of these effects can be suppressed by suppressing the expansion of the lid material 12. It is possible to prevent poor sealing due to. In addition, even if the lid | cover material 12 is flat form, it is prevented that a center part is heated directly.

  Then, cooling water is supplied as a cooling medium to the hollow part 23 a of the heat welding member 23 through the cooling medium pipe 24 while the heat welding member 23 of the seal head 21 is pressed against the heat seal part 12 a of the lid member 12. After forcibly cooling, the heat sealing of one container 10 is completed by raising the seal head 21 via the elevation pressing mechanism.

  Thus, even when the heating temperature for heat sealing is increased, the heat welding member 23 of the seal head 21 is cooled and the pressing is finished. It is possible to prevent sticking materials (such as heat sealing films) from sticking, and to perform high-speed and stable heat sealing. Therefore, it is possible to heat-seal and apply materials that are conventionally said to be difficult to heat-weld, such as polyester resins such as polyethylene terephthalate and polyethylene naphthalate, and polyamide resins such as nylon as a lid material. The range can be expanded.

  Further, a material that prevents thermal welding with the heat seal portion 12 of the lid member 12, for example, fluorine resin or polyimide, is applied to at least the surface of the seal head 21 that is in contact with the heat seal portion 12 a of the lid member 12. By forming the covering layer 30 that has been covered, it is possible to more completely prevent the cover member 12 from sticking.

  On the other hand, in order to prepare for the heat sealing of the next container, the cooling medium supplied to the hollow portion 23a of the heat welding member 23 is discharged by providing the cooling medium discharging means 31 so that the next heating can be performed easily and in a short time. You may be able to do it. As the cooling medium discharging means 31, for example, a switching valve 32 is provided in the cooling medium pipe 24 to supply a fluid having a smaller heat capacity than the cooling medium, for example, compressed air 33, and the cooling medium is hollow in the heat welding member 23. At the same time as discharging and collecting from the portion 23a, it is replaced with air.

  This makes it possible to shorten the heating time by replacing with air having a small heat capacity as compared with the cooling water as the cooling medium in the hollow portion 23a of the heat welding member 23, and to increase the speed of heat sealing. Can do.

  Furthermore, an electric heater 34 that constitutes a temperature holding means is provided adjacent to the heat welding member 23 of the seal head main body 22 so that the heating to the next heat seal can be performed in a shorter time after the seal head 21 is cooled. After being installed and cooled to a temperature at which the lid 12 can be prevented from sticking, the temperature is controlled so that the temperature does not decrease any further, and the temperature that serves as the reference temperature range for heating and cooling (the lowest temperature range) Temperature).

  As a result, even when the heat welding member 23 of the seal head 21 is subjected to high-frequency induction heating by the high-frequency heating coil 25, the temperature is already held by the electric heater 34 or the like constituting the temperature holding means to the minimum temperature necessary for heat sealing. Therefore, it suffices to heat the minimum temperature within this temperature range as a reference (heating start temperature), and the heat welding member 23 can be heated to the heat seal temperature in a shorter time.

  In the case of performing high-speed continuous heat sealing using such a heat sealing apparatus 20, for example, a rotary heat sealing apparatus 40 (hereinafter simply referred to as a heat sealing apparatus 40) having a schematic planar arrangement shown in FIG. Configure as.

  In this heat seal device 40, the container body 11 filled with the contents is received at the container body supply position A of the rotary type container body transport mechanism 41 and is rotated and transported to the lid material supply position B. At position B, the lid 12 transported by the rotary lid transport mechanism 42 from the lid stack position C of the lid 12 is placed on the container body 11, and then rotated and transported to the heating position D of the container body transport mechanism 41. To do.

  Then, at the heating position D, the seal head 21 induction-heated by the high-frequency induction heating coil 25 is moved down to heat and press the heat seal portion 12a of the lid member 12, and while rotating this state, the cooling head E is rotated. Transport.

  Then, cooling water as a cooling medium is supplied from the cooling medium pipe 24 to the hollow portion 23a of the heat welding member 23 at the cooling position E to start cooling, and the seal head 21 is raised at the container discharge position F, The container 10 that has been sealed is discharged.

  Thus, the heat sealing of one container is completed during the rotational conveyance from the container main body supply position A to the container discharge position F. However, while the seal head 21 is returned from the container discharge position F to the heating position D, the cooling medium is discharged. Or high frequency induction heating required for the next heat seal.

  According to the heat seal device 40 combined with such a rotary type transport mechanism, the heat seal can be finished by cooling while keeping the pressed state of the seal head, and can be continuously heat sealed at a high speed. For example, compared with the conventional heat sealing speed of 20 to 30 pieces per minute, according to the heat sealing apparatus 40, about 600 pieces of high speed sealing can be performed per minute.

  In the above-described embodiment, the case where the container is configured by covering the cup-shaped container body with a lid member provided with a lid portion as an example has been described. It may be a lid member having another shape such as a flat plate shape.

  In addition, as the contents to be filled in the container, heat sealing can be performed continuously at high speed, so that beverages filled in metal cans, PET bottles and the like are conventionally filled and sealed at high speed. good.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view showing a container according to an embodiment of the container heat seal method and apparatus of the present invention. It is a longitudinal cross-sectional view concerning one Embodiment of the heat-sealing method of the container of this invention, and the heat-sealing apparatus concerning one Embodiment of the apparatus. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic plan view concerning one Embodiment which applied the heat sealing method and the apparatus of the container of this invention to the rotary heat sealing apparatus which performs a high-speed continuous heat sealing. It is the schematic block diagram and the cross-sectional view of the conventional heat seal apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Container 11 Container main body 11a Flange part 12 Cover material 12a Heat seal part 12b Drop cover part 20 Container heat seal device 21 Seal head 22 Seal head main body 23 Heat welding member 23a Hollow part 24 Cooling medium piping 25 High frequency heating coil 26 Power supply member 27 Cooling medium piping 28 Ferromagnetic material 29 Container support member 30 Cover layer 31 Cooling medium discharge means 32 Switching valve 33 Air 34 Electric heater (temperature holding means)
40 Rotary Heat Seal Device 41 Container Body Transfer Mechanism 42 Cover Material Transfer Mechanism A Container Body Supply Position B Cover Material Supply Position C Cover Material Stack Position D Heating Position E Cooling Position F Container Discharge Position

Claims (4)

When the lid material is thermally welded and sealed to the flange portion provided in the opening of the container,
After the high frequency induction heating is performed on the seal head formed in the shape of the flange portion of the container, the lid is welded by supplying a cooling medium into the shield head while pressing the heated seal head. A method for heat-sealing a container, wherein compressed air having a smaller heat capacity than that of a cooling medium is supplied to discharge and collect the cooling medium and replace it with air . A container heat seal device including a seal head that heat seals and seals a lid member on a flange portion provided in an opening of the container,
A heat welding member formed in the shape of the flange portion provided in the seal head main body, a high frequency induction heating coil provided in the seal head main body for high frequency induction heating the heat welding member,
A cooling medium flow path that can be cooled while being pressed against the lid provided on the heat welding member;
A cooling medium discharging means provided on the heat welding member and capable of supplying compressed air having a heat capacity smaller than that of the cooling medium after cooling the lid member to discharge and collect the cooling medium in the cooling medium flow path and replace it with air. A container heat-sealing device. The heat sealing apparatus for a container according to claim 2 , wherein a non-welding member is coated on a pressing surface of the heat welding member with the lid member. The container heat seal device according to claim 2 or 3, wherein the seal head body is provided with a temperature holding means capable of holding a heating temperature of the heat welding member.

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