JP4141252B2 - Composite cap capping method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, a composite cap comprising a plastic cap body having an annular ceiling wall having an opening at the center of the top surface and a metal inner lid fitted inside the annular ceiling wall is wound around a container mouth. The present invention relates to a method and an apparatus for capping a composite cap.
[0002]
[Prior art]
Conventionally, for example, a composite cap 20 as shown in FIG. 4 has been put into practical use (see Patent Document 1). The composite cap fits inside the annular top wall 22 with a plastic cap body 25 having an annular ceiling wall 22 having an opening 21 at the center of the top surface and a cylindrical skirt 23 depending from the periphery of the annular ceiling wall. And an inner lid 26 made of metal. On the inner peripheral surface of the cylindrical skirt 23, a threaded portion 31 that engages with a threaded portion formed in the container mouth is formed. This cap has a metal inner lid that is in close contact with the cap body and the top surface of the container. The cap body is separated from the cap body. Then, since the metal inner lid is unsealed, the opening torque is reduced and the opening is easy, and the seal is not broken unless the tamper evidence band breaks. Yes. In addition, since the part covering the container mouth is made of a metal plate with a higher gas barrier property than synthetic resin, there is also an advantage of superior gas barrier properties compared to synthetic resin caps. Advantages of synthetic resin caps It has the feature that it also has the advantage of a metal cap.
[0003]
However, in the case of this cap, the metal inner lid 26 is simply fitted inside the annular top wall 22 of the cap body 25, so that the metal inner lid 26 is exposed on the outer surface and exposed to the outside air. The container is sealed only by the contact between the top of the container and the lower peripheral edge of the metal inner lid 26, and there is a problem that the sealing performance is inferior unless the part is securely sealed. Conventionally, in this kind of cap, a liner material 28 such as packing or compound is attached or applied to the peripheral edge portion 27 of the inner lid lower surface that comes into contact with the container mouth top portion, and the container top portion becomes the liner material 27 by the tightening torque at the time of closing the cap. Sealing is ensured by pressure bonding to the liner, and the adhesion between the liner material and the container mouth is particularly important. The liner material 27 is elastic and exhibits an excellent sealing property when in close contact with the container mouth, but there is a drawback that the adhesiveness between the two depends on the magnitude of the winding torque and the temperature.
[0004]
On the other hand, since the liner material attached to the peripheral portion 27 on the lower surface of the cap inner lid has a remarkable change in rigidity due to temperature change due to the characteristics of the plastic, even if it is wound with a constant torque by the capper, the tightening angle depends on the cap temperature. On the other hand, if the tightening angle is insufficient, the sealing performance is deteriorated. Conversely, if the tightening angle is too large, a large opening torque is required at the time of opening. For this reason, the capping is required to be wound with a constant torque and a constant angle. In order to satisfy this requirement, in conventional joint tightening, the entire cap is heated to a constant temperature (30 ° C to 35 ° C in the case of a hot pack) with hot air or steam before tightening, and the resin is always kept at a constant temperature condition. The same winding angle is obtained by keeping and tightening (see Patent Document 2).
[0005]
[Patent Document 1]
Japanese Patent No. 2620554 [Patent Document 2]
JP-A-2002-145391 [0006]
[Problems to be solved by the invention]
In the case of the composite cap as described above, the sealing performance by the liner is more important than the normal cap for the reason described above. The liner is elastic and has excellent adhesion to the top of the container, but sufficient sealing performance cannot be obtained unless it is tightened with a strong tightening torque. Depending on the case, sufficient sealing performance may not be obtained. However, if the winding torque is too large, there is a problem that it is difficult to open the plug, and the closing torque cannot be increased beyond a certain level. On the other hand, the liner increases its elasticity by heating, but even if the entire cap is heated to a heating temperature of about 30 to 35 ° C. when the plastic cap is tightened, the effect of improving the sealing performance of the liner is almost obtained. Not.
[0007]
Therefore, the present invention can always stably and securely wind a composite cap including a plastic cap body having an annular ceiling wall having an opening in the center and a thin metal inner lid without increasing the closing torque. It is another object of the present invention to provide a composite cap capping method and apparatus capable of reliably sealing and applying the composite cap as described above even in the case of contents requiring a high level of sealing performance.
[0008]
[Means for Solving the Problems]
A capping method for a composite cap according to the present invention that solves the above-described problems includes a plastic cap body having an annular ceiling wall having an opening at the center of the top surface, and a cylindrical skirt hanging from the periphery of the annular ceiling wall, and the annular ceiling wall. A capping method for winding a composite cap composed of a metal inner lid that fits inside a wall to a container mouth, and capping only a liner portion provided inside the metal inner lid of the composite cap It is characterized in that it is heated to an appropriate temperature immediately before winding. The liner is heated by induction heating of the metal cap of the composite cap immediately before winding, preferably by high frequency induction heating, and the liner is preferably heated to 40 to 80 ° C. Depending on the material of the liner, it will soften to the optimum state in the range of 40-80 ° C and the sealing performance will be effectively obtained. The above range is preferred because it softens and results in energy loss.
[0009]
The composite cap capping device of the present invention that solves the above problems includes an annular ceiling wall having an opening at the center of the top surface, a plastic cap body having a cylindrical skirt hanging from the periphery of the annular ceiling wall, and the annular ceiling wall. A capping device for tightening a composite cap composed of a metal inner lid fitted inside the container mouth, on the outer periphery of a cap feed turret that supplies the composite cap to the container mouth, or from the feeder to the container mouth An induction heating coil for heating the metal inner lid of the composite cap is arranged on the outer periphery of the chute to be supplied to the inner wall of the metal inner lid by heating the metal inner lid by induction heating. The liner is heated.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the embodiments shown in FIGS.
FIG. 1 shows a capping device according to an embodiment of the present invention, in which a composite cap 20 stored in a hopper 2 of a parts feeder 1 passes through a chute 3 and is supplied to a cap turret 4. As shown in the schematic plan view, one is fitted into the pocket 5 of the cap turret 4 and sent out at a constant pitch. On the other hand, the containers filled with the contents by the filling machine and transported by the container transport conveyor 6 are aligned at the same pitch as the pockets 5 of the cap turret 4 by the infeed screw conveyor 7 and reach the discharge position of the cap turret. The cap delivered from the cap turret 4 is fitted into the container mouth, and is wound by the capping head 8 to perform capping. The above capping method is the same as the conventional one, and the capping device is not limited to the one shown in FIG. 1. For example, any type of capping device such as a method of supplying a cap directly to a capping head without providing a cap turret. Can be adopted.
[0011]
In the conventional capping apparatus as described above, the present invention devises a composite cap as shown in FIG. 4 so that a good sealing property can be obtained and stable winding can be performed. As a result of various studies conducted by the present inventor to ensure the sealing performance of the composite cap, the material is softened by heating the liner to 40 to 80 ° C., and stability and good sealing with a constant tightening torque are obtained. Thus, the present invention has been achieved. Conventionally, the entire cap is heated to 30 to 35 ° C. with steam or hot air in order to obtain the same winding angle while keeping the temperature condition constant when winding the synthetic resin cap. The purpose of this is to keep the winding environment temperature constant as described above, and to always obtain a constant tightening torque regardless of seasonal fluctuations. There was no technical idea of heating to a high temperature. Therefore, in order to improve the sealing performance, the cap has not been heated to a high temperature. However, in order to warm the liner to 40 to 80 ° C. by a conventional method, When the hot air is heated to 80 ° C. or higher, the cap body made of synthetic resin is also heated. As a result, the skirt wall is deformed and cannot be capped. In order to solve the problem, the present invention employs induction heating, particularly high frequency induction heating means, as a method for heating only the liner portion.
[0012]
In this embodiment, in order to wind the composite cap 20 as shown in FIG. 4, the high frequency induction heating coil 10 is disposed on the outer peripheral portion of the cap turret 4, and the metal inner lid 26 of the composite cap immediately before winding. Is heated by high frequency induction heating. In the induction heating, an alternating magnetic field is applied to a conductive object to be heated, and heat is generated by hysteresis loss and eddy current loss. Therefore, only the conductive metal inner lid can be heated. Therefore, the cap body made of synthetic resin can selectively heat only the liner portion of the metal inner lid to a desired temperature without being directly heated. Even if only the metal inner lid is heated, heat is transferred from the metal inner lid to the cap body made of synthetic resin by heat conduction, but it is only the portion where the metal inner lid is in contact with the metal inner lid. Even when heated to a high temperature, the cap body is hardly affected, and the skirt wall is not deformed during winding.
[0013]
In this embodiment, the high-frequency induction heating device is controlled so that the metal cap 26 is heated to approximately 300 to 150 ° while the composite cap passes between the high-frequency induction heating coils 10 disposed on the upper and lower surfaces of the cap turret 4. Is done. When the metal inner lid is heated to the temperature, the liner material 28 applied to the inner surface side of the metal inner lid 26 is heated to 40 to 80 ° C. and softened by heat conduction. In this state, the composite cap 20 is fitted into the container mouth, and is tightened with the winding head 8. At that time, if the container is always tightened with a constant tightening torque, the top of the container always enters and adheres to the liner in a certain amount, and high sealing performance is maintained. Therefore, a constant winding angle can be stably obtained with respect to a constant tightening torque, and the winding can be performed in a highly sealed state without impairing the unsealing property. If a cap 30 is provided on the inner peripheral surface of the cap skirt wall of the cap body so as to engage with the metal inner lid when the cap is opened, the engaging projection 30 can be turned to the outer periphery of the metal inner lid by turning the cap body when the cap is opened. The metal inner lid can be lifted by engaging with the surface and can be easily opened.
[0014]
In the above embodiment, the heating coil 10 is arranged on the upper and lower surfaces through which the pocket 5 of the cap turret 4 fitted with the composite cap passes. However, the present invention is not necessarily limited to this, and is indicated by a phantom line in FIG. As such, it may be provided on a part of the chute 3. The state of that portion is schematically shown in FIG. The high-frequency induction heating coil may be appropriately arranged so as to heat the metal inner lid 26 most effectively. However, the high-frequency induction coil is arranged so that the outer peripheral portion of the metal inner lid generates heat intensively. By doing so, heating of the central part of the metal inner lid can be suppressed, and only the outer peripheral part to which the liner material is applied can be effectively heated, and energy efficiency can be increased. As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible within the range of the technical idea. Moreover, although the high frequency induction heating is desirable for heating the metal inner lid as in the above embodiment, low frequency induction heating using a commercial frequency is also possible.
[0015]
【The invention's effect】
As described above, according to the method and apparatus for capping a composite cap of the present invention, in a composite cap comprising a plastic cap body having an annular ceiling wall having an opening in the center and a thin metal inner lid, a synthetic resin is used. Only the metal inner lid can be heated to the required temperature without affecting the cap body, and a constant winding angle can be stably obtained with respect to the constant tightening torque, without increasing the closing torque. Can be reliably sealed, can be wound in a highly sealed state without impeding the opening, and the composite cap can be applied even to contents that require a high degree of sealing. .
[Brief description of the drawings]
FIG. 1 is a schematic front view of a composite cap capping apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic plan view of the cap turret portion.
FIGS. 3A and 3B are schematic diagrams showing the arrangement of high-frequency induction heating coils, where FIG. 3A shows a case where the coil is arranged on a cap turret, and FIG. 3B shows a case where the coil is arranged on a chute.
FIG. 4 is a partial sectional front view showing an example of a composite cap to which the present invention is applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Feeder 2 Hopper 3 Chute 4 Cap turret 6 Container conveyance conveyor 7 Infeed conveyor 8 Capping head 10, 11 High frequency induction heating coil 20 Composite cap 21 Opening 22 Annular ceiling 25 Plastic cap main body 26 Inner lid 28 Liner material 31 Screw part

Claims (3)

A composite comprising a plastic cap body having an annular ceiling wall having an opening at the center of the top surface, a cylindrical skirt hanging from the periphery of the annular ceiling wall, and a metal inner lid fitted inside the annular ceiling wall A capping method for winding a cap around a container mouth, comprising heating a liner provided inside a metal inner lid of the composite cap immediately before capping and winding the cap ,
The heating of the liner is performed by heating the metallic inner lid being conveyed by induction heating by induction heating coils arranged on both sides of the path through which the metallic inner lid passes, and the liner is heated. A method for capping a composite cap, characterized by heating to 40 to 80 ° C. A composite comprising a plastic cap body having an annular ceiling wall having an opening at the center of the top surface, a cylindrical skirt hanging from the periphery of the annular ceiling wall, and a metal inner lid fitted inside the annular ceiling wall An inductive heating coil arrangement for heating a metal inner lid of the composite cap on a top and bottom surface through which a pocket of a cap feed turret for supplying the composite cap to the container mouth passes , wherein the cap is wound around the container mouth And the inner cap of the metal is heated by induction heating so that the liner provided inside the inner cap of the metal is heated to 40 to 80 ° C. . A composite comprising a plastic cap body having an annular ceiling wall having an opening at the center of the top surface, a cylindrical skirt hanging from the periphery of the annular ceiling wall, and a metal inner lid fitted inside the annular ceiling wall Induction heating for capping a cap around a container mouth, wherein the inner cap of the composite cap is heated on both sides through which the composite cap passes through a chute that feeds the composite cap from a feeder to the container mouth. The composite cap capping is characterized in that a coil is arranged and the liner provided inside the metallic inner lid is heated to 40 to 80 ° C. by heating the metallic inner lid by induction heating. apparatus.

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