JP2001122205A - Top sealing method for paper container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a top sealing method using a board of 400 g/m2 or more basis weight and also provide the bonding strength strong enough even for a paper container with a mouth edge of insufficient wrap-over performance. SOLUTION: A top face of a mouth edge section 13 and a cover 20 corresponding to the top face are heat sealed by using an annular top face heater 1 and using the force in the up and down direction (primary sealing), and then the mouth edge section and the corresponding cover are heat sealed by using a cap-shaped top face heater 2 and utilizing the force in the up and down direction along the mouth edge section curling outwardly in a manner of overlapping the top face heat sealed in the primary sealing (secondary sealing), and lastly the outwardly curled mouth edge section and the corresponding cover are heat sealed by using a mouth edge pressing heater 3 and utilizing the force in the horizontal direction (third sealing) to continuously heat seal all through from the top face to the mouth edge section of a paper container.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sealing a top of a paper container, and more particularly to a method for sealing a top of a paper container having an edge with an insufficiently entangled periphery.

[0002]

2. Description of the Related Art Conventionally, as a container for storing a substance which dislikes moisture, such as a bath salt, a powdered detergent, instant coffee, and powdered milk, as a content, a metal container, a plastic molded container, or paper is mainly used. Containers made of various materials are used, such as a paper tube container made of paper and metal, in which a paper tube in which a strip to be formed is spirally wound is used as a side wall, and a molded metal plate is used as a top plate or a bottom plate.

However, with the enforcement of the Containers and Packaging Recycling Law, there has been a movement toward the use of a single material for packaging materials that can be easily separated and disposed of, or a composite container mainly composed of paper and plastic that is easy to dispose of. Attention has been focused on paper containers having hermetic properties.

In this case, a lid placed so as to cover the opening is attached to the rim of the paper container having the rim whose outer periphery is curled outward. And a method of hermetically sealing with.

In the case of a paper container using a paperboard having a basis weight of about 400 g / m ² or less as a base material, since the periphery of the opening can be completely wrapped outward, a curled outward opening can be obtained. The edge portion can be pressed from above and below to crush flat, and as shown in FIG.
1, a sufficient bonding area can be secured, and complete sealing is maintained even when dropped or vibrated.

However, as a substrate, approximately 400 g / m ²
In the case of a paper container using paperboard having the above basis weight, the periphery of the opening cannot be completely rolled out,
Therefore, it is impossible to press the lip from above and below to flatten it, and as shown in FIG. 4 (b), the seal is a linear seal, having a narrow seal area 52, and sufficient adhesion. Area could not be secured, resulting in insufficient bonding strength,
There is a problem that the top seal is easily peeled off when dropped or vibrated.

However, a paper container made of a liquid or powder having a storage amount of 500 g or more is required to have a substrate having a basis weight of 400 g / m ² or more in order to maintain the container's independence, external dimensions, and shape. Must be used. Paperboard having such a basis weight has the above-mentioned problem because of its high rigidity.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a basis weight of 40
Focusing on the above-mentioned problems relating to a paper container having an insufficiently wrapped lip using a paperboard of 0 g / m ² or more, the paperboard having a basis weight of 400 g / m ² or more It is an object of the present invention to propose a method of a top seal having a strong adhesive strength even for a paper container having an insufficiently entangled lip portion, using the same.

[0009]

Means for Solving the Problems A first invention of the present invention is:
The edge of a paper container having a body and a bottom, the edge of which is curled outward, and a lid placed so as to cover the opening, the edge of the edge of the paper container. A top sealing method for a paper container, which is hermetically sealed by a first sealing method. First, the top surface of the rim and the corresponding lid material are heat-sealed with a vertical force, and then the second sealing is performed. As a vertical force, heat sealing the rim and the corresponding lid material along the rim curled outward so as to overlap the top surface heat-sealed with the primary seal with the vertical force, and finally, As a tertiary seal, the outer edge curled outward by a horizontal force and the corresponding lid material are heat-sealed, and the paper container is continuously connected from the top surface to the outwardly curled edge. This is a top sealing method for a paper container, wherein the top container is heat-sealed.

A second invention is a top sealing method for a paper container according to the first invention, wherein a peripheral edge of a lid material covering an opening is trimmed simultaneously with the primary sealing. .

As described above, according to the present invention, as the primary seal, the top surface of the rim and the corresponding lid material are heat-sealed by the vertical force, and then as the secondary seal, The outer edge and the corresponding lid material are heat-sealed along the edge curled outward so as to overlap the top surface heat-sealed by the primary seal with the force of the first seal, and finally the tertiary seal As a result, the outer edge curled outward by the horizontal force and the corresponding lid material are heat-sealed, and the heat sealing is continuously performed from the top surface of the paper container to the outer curled edge. Therefore, even for a paper container having an edge portion that is not sufficiently entrained, the sealing area is large, a sufficient bonding area can be secured, and complete sealing can be maintained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments. FIG. 1 shows a paper container in which a lid material is sealed using the paper container top sealing method of the present invention, and FIG. 2 is a schematic explanatory view showing the paper container top sealing method of the present invention.

First, as the body member, a total thickness of 0.49 mm consisting of [container outside] polyethylene (PE) / paperboard (basis weight: 400 g / m ² ) / polyethylene terephthalate film (PET) / PE [container inside] Was prepared. As the bottom member, [outside the container] PE /
A composite sheet composed of paperboard (basis weight; 350 g / m ² ) / PET / PE [outside the container] and having a total thickness of 0.41 mm was prepared.

Using the body member and the bottom member, a paper container 10 was manufactured using a general paper cup forming machine.

However, in this paper container 10, since the rigidity of the paperboard used for the body member is high, the periphery of the edge of the body portion is not completely wrapped outside, and is in a state as shown in FIG. 1 or FIG. Is formed.

Separately, for the cover material, [outside the container] PET
/ Aluminum foil (Al) / PE [inside of container], a composite sheet having a total thickness of 0.067 mm was prepared.
Using a punching machine from this composite sheet, a lid member 20 having substantially the same outer shape as the opening 14 of the paper container and having a knob 21 projecting from the opening was produced.

The lid member 20 thus obtained is placed in the paper container 1
The opening 14 was covered with the opening 14 so as to cover the opening.

The method for hermetically sealing the periphery of the opening will be described in detail with reference to FIGS. 2 (a), 2 (b) and 2 (c).

First, as the primary seal, the top surface of the lip 13 and the lid member 20 are melt-bonded by the annular top heater 1 capable of pressing vertically. At this time, an unnecessary portion of the lid material around the opening may be cut off by the trimming cutter 4 at the same time as the sealing (see FIG. 2A).

Next, as a secondary seal, the lip and the lid are joined along the curving surface of the lip curled outward so as to overlap the top surface fused and bonded by the primary seal. Then, the cap-like top heater 2 having a curved surface substantially the same as the winding curved surface of the rim that can be pressed in the vertical direction is melt-bonded (see FIG. 2B).

Finally, as a tertiary seal, an edge presser heater 3 having an inwardly curving surface which is substantially the same as an inwardly curving curved surface of an inward edge which can press horizontally in the horizontal direction and a lid member. (See FIG. 2 (c)).

By the pressure and heating performed in the above three stages, the lid member 20 is completely adhered along the curved surface of the rim portion 13 with a large sealing area.

[0023]

As described above, when the top sealing method for a paper container according to the present invention is used, the lid material is heat-sealed along the curved surface of the edge of the paper container. The edge and the lid material are heat-sealed to produce a paper container having a strong adhesive force.

[Brief description of the drawings]

FIG. 1 is a perspective explanatory view showing a state in which a paper container and a lid member manufactured by using the paper container top sealing method of the present invention are top-sealed. FIG. It is sectional explanatory drawing.

FIG. 2 is an explanatory view schematically showing a top sealing method for a paper container of the present invention, wherein (a) is a primary seal, and (b) is a primary seal.
Indicates a secondary seal, and (c) indicates a tertiary seal.

FIG. 3 is an explanatory cross-sectional view of a main part showing a state in which a lid member is thermally fused to a paper container using the paper container top sealing method of the present invention.

FIG. 4 shows a conventional paper container top sealing method.
It is principal part sectional explanatory drawing which shows the state in which the lid material was heat-sealed to the paper container, (a) is a paper container which used the paperboard of 400 g / m < ² > or less as a base material, (b) Is 400 g / m on the substrate
^This is a case of a paper container using a paperboard having a basis weight of ² or more.

[Explanation of symbols]

 1 Top Ring Heater 2 Top Hat Heater 3 Edge Heater 4 Edge Trimming Cutter 10 Paper Container 11 Body 12 Bottom 13 Edge 11 {Opening 20} Lid 21} Knob 51} Wide sealing area 52} Narrow sealing area

Continued on the front page F term (reference) 3E049 AA05 AB03 BA03 DB01 FA06 FA07 3E094 AA06 BA06 CA02 DA02 FA14 HA08 HA10

Claims (2)

[Claims] 1. An edge of a paper container having a body and a bottom and having an edge curled outwardly around an opening, and a lid placed so as to cover the opening. A top sealing method for a paper container that hermetically seals at the periphery of the rim, as a primary seal, first heat sealing the top surface of the rim and the corresponding lid material with a vertical force; Next, as a secondary seal, the edge and the corresponding lid material are heat-sealed along the edge curled outward so as to overlap the top surface heat-sealed with the primary seal by a vertical force. Sealing, and finally, as a tertiary seal, the edge portion curled outward by a horizontal force and the corresponding lid material were heat-sealed and curled outward from the top surface of the paper cup-shaped container. A top sealing method for a paper container, wherein heat sealing is continuously performed up to an edge portion. 2. The method according to claim 1, further comprising trimming a peripheral edge of the lid material covering the opening simultaneously with the primary seal.
The top sealing method of the paper container described in the above.