JP2002321701A - Sealing method for container and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing method for a container and its device by which a loading process of a heat shrinking film onto an opening of the container, cutting off process, an adhering process for the heat shrinking film cut off to the container and the like can be automated when the opening of the container is sealed by the heat shrinking film. SOLUTION: A container body 11 is retained in a lower mold 2 with the opening upward, the heat shrinking film F which becomes a cover member provided at the opening in tension is clipped by a cutter mounted on the upper mold. Then the outer circumference edge of the clipped heat shrinking film F is heated by a hollow portion 6b formed on the upper mold while the heat shrinking film F positioned on the opening is covered by a protective member 9 and during heating the film is shrunk along the outer circumference wall of the opening of the container body 11 to seal the opening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for sealing a top film type container mainly for storing food, and to a packaging technique.

[0002]

2. Description of the Related Art Many foods and various other articles are stored in plastic or paper cups and trays, and the openings thereof are made of plastic or paper films or sheets, and a molded lid (hood). It is provided to the market in a sealed form. Among these, when the container is to be covered with a plastic film or sheet, use an adhesive, heat sealing (heat sealing), heat shrinkage, or the like. A method based on heat shrinkage using a conductive film or sheet is employed.

[0003]

Generally, a method of sealing a container by heat shrinkage is to cut out a shape to be used as a lid from a prepared heat-shrinkable film or sheet. The shape is adjusted according to the opening of the container (molding). ) Step of covering the opening of the container The step of heating and shrinking the heat-shrinkable film or sheet portion bent along the outer wall below the opening of the container is performed in this order.

[0004] However, in these methods, automation is strongly demanded in order to reduce costs and further in terms of hygiene when handling food, and various proposals have already been made. At present, there is no effective means in the heat shrinking method using a sheet, and no proposal has been made.

Therefore, in sealing a container using a heat-shrinkable film or sheet, efforts have been made to automate the above process, which is the most hindrance in automation, and a heat-shrinkable film or sheet is cut using a cutter having a cutting blade at the tip. At the same time that the sheet is cut out in the shape of a lid, the outer edge of the cut-out heat-shrinkable film or sheet is bent along the outer peripheral wall of the container, and temporarily contracted by heat-shrinking the heat-shrinkable film or sheet to the opening of the container. And then found that automation could be achieved by sealing, or by sealing without temporary fixing,
The present invention has been completed.

That is, according to the present invention, when the opening of the container is sealed with the heat-shrinkable film, at least the heat-shrinkable film is loaded into the opening of the container, cut, and the cut heat-shrinkable film is temporarily attached to the container. It is an object of the present invention to provide a method and an apparatus for sealing a container which can automate a stopping step and the like.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a heat-shrinkable film serving as a lid member stretched over an opening of a container main body is cut out and cut. A method for sealing a container, characterized in that the cutout heat-shrinkable film is shrunk along the outer peripheral wall of an opening of the container while heating the outer edge of the cutout heat-shrinkable film, thereby sealing the opening.

According to a second aspect of the present invention, a heat-shrinkable film serving as a lid member stretched over an opening of a container is cut out, and an outer peripheral edge of the cut-out heat-shrinkable film is heated. While the container is primarily contracted along the outer peripheral wall at the opening of the container, and the heat-shrinkable film is temporarily fixed to the opening of the container, the outer peripheral edge of the heat-shrinkable film is further heated and secondarily contracted. A method for sealing a container, characterized in that the opening is sealed.

According to a third aspect of the present invention, there is provided a method for sealing a container, wherein the primary shrinking step and the secondary shrinking step are performed in the same place.

According to a fourth aspect of the present invention, there is provided a method for sealing a container, wherein the primary shrinking step and the secondary shrinking step are performed in different places.

According to a fifth aspect of the present invention, the cutting and the primary shrinking of the heat-shrinkable film are performed by a cylindrical cutter member having a saw-toothed cutting edge at a leading edge. This is a method for sealing a container.

The invention according to claim 6 of the present invention comprises a lower mold capable of holding a container main body with an opening portion upward, and an upper mold movable vertically with respect to the lower mold. The upper mold has a film holding member for holding the heat-shrinkable film serving as the lid member in close contact with the upper surface of the lower mold without shrinking the heat-shrinkable film. A cylindrical cutter member for cutting larger than the shape of the part, and a protective member for preventing contraction by contacting the heat-shrinkable film on the opening of the container when cutting the heat-shrinkable film. A container sealing device characterized in that:

[0013] The invention according to claim 7 of the present invention is characterized in that the lower die has an opening step larger than the outer shape of the opening of the container main body to be hermetically sealed on the upper surface of the lower die having a required shape. Are formed, and the outer peripheral portion of the container main body is held continuously to the opening step, and a holding hole having a depth in which the opening of the container main body is flush with the upper surface portion is formed. It is a container sealing device.

[0014] The invention according to claim 8 of the present invention is characterized in that the upper mold has a cylindrical hollow portion at a portion facing the lower mold so as to accommodate an upper portion of a container main body to be sealed. A cylindrical cutter member is mounted on an outer peripheral portion of the hollow portion, and a saw-toothed cutting blade formed on a distal end edge thereof is mounted so as to protrude from a distal end portion of the hollow portion. It is a sealing device.

According to a ninth aspect of the present invention, the film holding member comprises a ring member or a frame member which is disposed on an outer peripheral portion of the upper die so as to be vertically movable, and wherein the lower die A thin elastic body is attached to a lower surface in contact with an upper surface of the container, and is constantly pressed in a lower mold direction by a biasing force of a spring.

According to a tenth aspect of the present invention, the protective member is provided in the hollow portion of the upper die and comprises a board having substantially the same shape as the opening of the container main body to be sealed. A container sealing device characterized in that the distal end surface always projects from the distal end portion of the hollow body, and is attached to the upper die so as to be vertically movable by a movable arm provided on the back surface portion.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a container sealing device according to the present invention will be described below in detail with reference to the accompanying drawings, and a method for sealing a container using the container sealing device will be described. .

The container sealing device 1 of the present invention comprises a lower die 2 capable of holding a container main body 11 whose opening is hermetically sealed, and an upper die which is vertically movable with respect to the lower die 2. And 5.

The lower mold 2 has a container main body 11 on an upper surface 2a.
A stepped opening 3 formed of a shallow concave portion having a shape larger than the outer shape of the opening is formed, and a cylindrical holding portion for holding the outer peripheral portion of the container main body 11 continuously to the stepped opening 3. The container main body 11 was held in the holding part 4 by setting the sum of the depth of the holding part 4 and the depth of the opening step 3 to be the entire height of the container main body 11. At this time, the edge of the opening of the container main body 11 is flush with the upper surface 2a.

The upper mold 5 has an upper mold body 6 and a film holding member 7 for holding the heat-shrinkable film F serving as a lid member in close contact with the upper surface 2a of the lower mold 2 without shrinking. And the sandwiched heat-shrinkable film F with the container body 1
In order to prevent shrinkage, the tubular cutter member 8 for cutting larger than the shape of the opening 1 and the heat-shrinkable film F on the opening of the container main body 11 are cut when the heat-shrinkable film F is cut. And a protection member 9 for use.

The upper mold main body 6 has a cylindrical hollow portion 6a which can accommodate the upper portion of the container main body 11 to be hermetically sealed at a portion facing the lower mold 2, and the outer periphery of the hollow portion 6a. The cylindrical cutter member 8 is provided with a saw-toothed cutting blade 8a formed at the leading edge of the tubular member 8 so as to protrude from the leading end of the hollow portion 6a. The peripheral portion of the heat-shrinkable film F cut by the cutter member 8 is pushed down by the outer peripheral portion 6b of the hollow portion 6a, and contracts while contracting. .

The upper main body 6 is made of a heat conductor, and has a mounting portion 6 for mounting a cartridge type heater (not shown) with a built-in nichrome wire above the hollow portion 6a.
c, 6c, and the heater has a hollow portion 6a
The heat capacity that does not adversely affect the cutting of the heat-shrinkable film F by the cut-out blade 8a at the tip of the cutter member 8 that is fixed to the outer peripheral portion of the heat-shrinkable film F by heat and enables sufficient heat shrinkage of the heat-shrinkable film F It is preferred to have

More specifically, the hollow portion 6a of the upper mold body 6
Although it depends on the material of the heat-shrinkable film, the temperature at the portion where the heat-shrinkable film F is shrunk by heating at the outer peripheral portion is usually preferably a temperature that can be heated to about 130 to 150 ° C.

At this time, if the temperature is lower than 130 ° C., the heat-shrinkable film F may not be sufficiently heat-shrinkable depending on the material. When cutting F, there is a possibility that the heat of the heat-shrinkable blade 3 melts the heat-shrinkable film F and cutting cannot be performed smoothly.

The film holding member 7 is composed of a ring member or a frame member arranged on the outer periphery of the upper die main body 6, and is basically provided at the opening of the container main body 11 to be sealed. In order to determine whether to form a ring or a frame according to the shape, the heat-shrinkable film F to be cut is placed on the lower mold 2 on the lower surface in contact with the upper surface 2a of the lower mold 2. A sheet-like thin elastic body 7a made of rubber or the like is integrally attached in consideration of adhesion to the heat-shrinkable film F and gripping properties so that the mold 3 can be held in a tensioned state. The distal end of an arm 7b provided on the back side is provided on a cylinder mechanism 10 so as to be movable up and down.
Is always urged downward, that is, in the lower die 2 direction.

The cutter member 8 is formed with a saw-toothed cutting blade 8a at the tip for smoothly cutting the thin heat-shrinkable film F, and utilizes the heat of the upper die main body 6. In order to soften the heat-shrinkable film F and facilitate cutting, it is preferable to use a metal having good heat conductivity.

When the outer edge of the cut heat-shrinkable film F is bent and shrunk by heating, the heat-shrinkable film F located at the opening of the container body 11 is bent. To prevent deformation under the influence of heat and heat, and to facilitate bending of the outer edge portion. Silicon rubber or the like having substantially the same shape as the opening of the container main body 11 to be sealed is used. A disk body made of an elastic heat insulating material, which is disposed in the hollow portion 6a of the upper die main body 6 and whose distal end surface always protrudes from the distal end portion of the hollow portion 6a, and is connected to the cylinder via a movable arm 9b provided on the back surface portion. It is linked to the mechanism 10 and is held so as to be vertically movable with respect to the upper mold main body 6.

Note that the movable arm 9b is
It is preferable that a spiral groove is formed in the outer peripheral portion so that heat from the battery does not accumulate, and the inside of the cylindrical hollow portion 6a formed in the upper die main body 6 is movable so as not to be in a vacuum state. It is preferable that air be communicated between the arm 9b and the upper mold main body 6.

When the protective member 9 holds the heat-shrinkable film F in cooperation with the opening edge of the container main body 11, the movable arm 9b moves upward. The heat-shrinkable film F is pressed by its own gravity regardless of the position.

Hereinafter, a sealing method for mounting the heat-shrinkable film F on the container main body 11 using the sealing device 1 having the above-described configuration will be described.

First, the container main body 11 sent by a conveyor means such as a belt conveyor is dropped into the holding section 4 from the opening step 3 of the lower mold 2 with the opening thereof facing upward, and is accommodated. Since the total depth of the step portion 3 and the holding portion 4 coincides with the overall height of the container main body 6, the opening edge of the container main body 6 automatically becomes flush with the upper surface portion 2a of the lower mold 2.

Then, although not shown, the heat-shrinkable film F is pulled out from a roll arranged near the lower mold 2 by appropriate means, and is placed in a state of being kept in a state of tension in the opening of the container main body 11.

When the heat-shrinkable film F is placed on the opening of the container main body 11, the upper die 5 descends toward the lower die 2 by the action of an air cylinder or the like under computer control. Elastic body 7a is in contact with the upper surface 2a of the lower mold 2, and holds the heat-shrinkable film F in a tensioned state.

Next, the cutter member 8 heated to a predetermined temperature is lowered, and the saw-toothed cutting blade 8a at the tip cuts the heat-shrinkable film F into a predetermined shape while softening it by heat. As shown in FIG. 2, the outer peripheral portion of the heat-shrinkable film F cut in the opening step 3 is closed by the container main body 11 by the tip of the outer peripheral portion of the hollow portion 6 a formed in the upper mold main body 6 that has been simultaneously lowered. Is bent toward the outer periphery of the opening.

The inside of the tip of the outer peripheral portion of the hollow portion 6a is
It is formed in a tapered shape so that the diameter decreases upward.

As shown in FIG. 2, the outer peripheral edge of the heat-shrinkable film F bent is the outer peripheral portion 6b of the hollow portion 6a.
Shrinks due to the heat of the heat shrinkable film F so that the outer peripheral edge of the heat shrinkable film F
And the opening of the container body 11 is sealed.

At this time, if the staying time of the outer peripheral portion 6b disposed at the opening of the container main body 11 is set to be long, the heat-shrinkable film F can be completely adhered to the opening. The stay time of the portion 6b is adjusted, and the outer peripheral edge of the heat-shrinkable film F is temporarily fixed to the outer peripheral portion of the opening of the container main body 11 so that the outer peripheral portion does not come off. 2, the heat-shrinkable film F is temporarily fixed to the container main body 11, and the plurality of container main bodies 11 are collected and treated so that heat is not applied to the heat-shrinkable film F on the opening of each container main body 11. After that, heat may be applied only to the outer peripheral portion of the opening of the container main body 11 so that the outer peripheral edge of the heat-shrinkable film F is secondarily contracted so as to be completely adhered to the container main body 11 and sealed.

The temporary fixing step is only required to prevent dust and dirt from entering the inside of the container main body 11 and to prevent the heat-shrinkable film F from being detached from the container main body 11. The heat-shrinkable film constituting the lid member may be in the form of a sheet.

The shape cut out from the heat-shrinkable film F is, for example, as shown in FIG. 3, when the opening mainly in the container is circular, the shape is cut out into a larger circle than the circle. The shape of the cutter member 8 is such that a part of the circumference protrudes outward as shown to form the protruding portion 8b, so that the heat-shrinkable film F is
When it comes into close contact with the outer peripheral portion, only the protruding portion 8b floats up and does not adhere, and serves as a tab for peeling the heat-shrinkable film F serving as a lid member from the container main body 11.

In the above adhesion method, means for supplying the container main body by a conveyor and supplying the heat-shrinkable film from a roll-shaped raw film may be provided by a method for removing the container main body to which the heat-shrinkable film is temporarily fixed or adhered. For example, all of the steps can be automated and can be made continuous by using conventionally known means.

[0041]

According to the container sealing method of the present invention, when the opening of the container is sealed with the heat-shrinkable film or sheet, the heat-shrinkable film is placed in contact with the opening of the container. At the same time, the heat-shrinkable film can be cut into a predetermined size, and the outer peripheral edge of the heat-shrinkable film can be temporarily fixed or completely adhered to the outer peripheral portion near the opening of the container main body. The lid mounting process is automated, and continuous automatic mounting is also possible by using known means. It has excellent effects such as simplification of the process, cost reduction, and enhancement of hygiene. .

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a container sealing device according to the present invention.

FIG. 2 is a conceptual diagram illustrating a sealing process by the sealing device.

FIG. 3 is a bottom view showing an example of an upper main body constituting the sealing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing device 2 Lower die 3 Opening step part 4 Holding part 5 Upper die 6 Upper die main body 7 Film holding member 8 Cutter member 8a Cutting blade 9 Protective member 10 Cylinder mechanism 11 Container main body

Claims (10)

[Claims] 1. A heat-shrinkable film serving as a lid member stretched over an opening of a container main body is cut out, and an outer peripheral edge of the cut-out heat-shrinkable film is heated while being attached to an outer peripheral wall of the container main body opening. A method for sealing a container, comprising: 2. A heat-shrinkable film serving as a lid member stretched over an opening of the container main body is cut out, and an outer peripheral edge of the cut-out heat-shrinkable film is heated while being heated at an outer peripheral wall of the container main body. After the heat-shrinkable film is temporarily fixed to the opening mainly in the container, only the outer edge of the heat-shrinkable film is heated and then secondarily shrunk, thereby sealing the opening. The method of sealing the container. 3. The method according to claim 2, wherein the primary shrinking step and the secondary shrinking step are performed at the same place. 4. The container sealing method according to claim 2, wherein the primary shrinking step and the secondary shrinking step are performed in different places. 5. The cutting and primary shrinking of the heat-shrinkable film is performed by a cylindrical cutter member having a saw-toothed cutting edge at a leading edge.
The method for sealing a container according to any one of claims 1 to 4. 6. A lower die capable of holding a container main body with an opening portion upward, and an upper die movable vertically with respect to the lower die, wherein the upper die is a lower die. A film suppressing member for holding the heat-shrinkable film which is in close contact with the upper surface portion and serving as a lid member without shrinking, and for cutting the held heat-shrinkable film larger than the shape of the opening of the container main body. Sealing of a container, comprising: a tubular cutter member; and a protection member for preventing contraction by contacting the heat-shrinkable film on the opening of the container when cutting the heat-shrinkable film. apparatus. 7. The lower mold has an opening step larger than the outer shape of the opening of the container to be hermetically sealed on the upper surface of the lower mold having a required shape, and is continuous with the opening step. 7. The container according to claim 6, wherein the outer peripheral portion of the container main body is held to form a holding hole having a depth such that the opening of the container main body is flush with the upper surface portion. apparatus. 8. The upper mold has a tubular hollow portion at a portion facing the lower mold so as to accommodate an upper portion of a container main body to be hermetically sealed. 7. The container sealing device according to claim 6, wherein the saw-shaped cutter member is mounted with a saw-toothed cutting blade formed at a front end edge thereof protruding from a front end portion of the hollow portion. 9. The film holding member comprises a ring member or a frame member which is vertically movable on an outer peripheral portion of the upper die, and has a thin elastic surface on a lower surface which is in contact with an upper surface portion of the lower die. 7. The container sealing device according to claim 6, wherein the body is attached and the body is constantly pressed in a lower mold direction by a biasing force of a spring. 10. The protection member, which is disposed in the hollow portion of the upper die and is made of a disk having substantially the same shape as an opening of a container main body to be hermetically sealed, and a front end surface of which is always provided. 7. The container sealing device according to claim 6, wherein the container protrudes from the tip of the hollow portion and is vertically movably attached to an upper die by a movable arm provided on a back surface portion.