JP2002037234A - Paper cup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper cup in which the structure thereof is not complicated, or the number of manufacturing processes is not increased thereby at all, the inside thereof is completely shielded from the outside, and the liquid content does not infiltrate the paper material. SOLUTION: A thermoplastic synthetic resin narrow tape having adhesivity is adhered to an inner surface side of a container having one side edge forming the inside of a barrel part of a blank in an expanding manner outwardly in the circumferential direction over the side edge from the inside of the circumferential direction of the side edge, and the paper cup is formed thereby in a regular method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the sealing structure of a paper cup for storing liquids such as milk drinks, juices, yogurts, gels and the like.

[0002]

2. Description of the Related Art Paper cups for storing liquids such as milk drinks, juices and yogurt, gels, and the like are provided on a body to which a side edge of a blank is adhered, a bottom wall, and a separately prepared lid piece or lid. It is provided to the general consumer in a sealed form and adhered to the material, providing complete insulation between the inside of the cup and the outside world, and complete prevention of infiltration of the content liquid into the paper material, the main material of the cup. Are essential requirements to be met.

[0003] In order to satisfy the essential requirements to be satisfied,
For example, Japanese Patent Publication No. 40-16868 and Japanese Patent Laid-Open No. 57-6
As disclosed in JP-A-3240, JP-B-63-24464 and JP-A-10-236454, various paper cup structures having various sealing properties have been proposed.

[0004] However, any of the structures achieves the purpose of completely blocking the outside of the cup from the outside and completely preventing the infiltration of the content liquid into the paper, but the structure becomes complicated and the number of manufacturing steps increases. However, there are problems such as high cost and poor production efficiency.

[0005]

In order to avoid the increase in cost and the reduction in production efficiency due to the complexity of the structure of the paper cup structure having the above-mentioned sealing property and the increase in the number of manufacturing steps, the present invention slightly reduces the number of blanks. Only one additional step of bonding a narrow tape of thermoplastic synthetic resin with adhesive ability to the side edge enables complete insulation between the inside of the cup and the outside world and complete prevention of infiltration of the content liquid into the paper quality. It is an object to provide a paper cup structure that can be achieved.

[0006]

According to the first aspect of the present invention, a body of a cardboard made of cardboard is provided with
A blank is formed into a tubular shape, and both side edges are formed by means of overlapping and bonding, and the cup is overlapped and bonded over the entire length in the cup height direction of the side edge inside the cup among the bonded side edges. A narrow tape of a thermoplastic synthetic resin having an adhering ability and projecting from the inner side in the circumferential direction of the side edge to the outer side in the circumferential direction beyond the side edge is bonded and arranged on the inner side surface.

[0007] The narrow tape is welded so as to cover at least the overlapped portion on both sides of the blank inside the body portion, and at the bonding portion between the bottom wall peripheral edge and the lower end edge portion of the body portion, Due to the thickness of the glued overlap on both sides of the blank inside the torso,
Between the bottom wall periphery and the trunk portion, the tunnel portion, which is a gap formed along the inner side edge, is melted by heating and pressing at the time of adhesive molding between the bottom wall periphery and the trunk bottom edge. The structure was filled with the narrow tape and sealed.

In the second aspect of the present invention, the narrow tape of the thermoplastic synthetic resin is welded so as to cover the overlapped portions of the outward flanges formed on the upper edge of the body at the both side edges of the blank. Is added to the first aspect of the present invention.

According to a third aspect of the present invention, the thickness of the narrow tape made of thermoplastic synthetic resin having an adhesive ability is 50 μm to 25 μm.
A configuration in which the thickness is selected in accordance with the thickness of the blank within a range of 0 μm is added to the invention of claim 1 or claim 2.

[0010]

1 to 8 show an embodiment in which the first, second and third aspects of the present invention are applied together. A paper cup 1 shown in FIG. 2, a fan-shaped cardboard blank 2 shown as a development view is wound so as to form a cylindrical shape as shown by an arrow X, and one side edge 4 is formed.
The body portion 5 is formed by overlapping and bonding the outer side surface of the other side edge 3 to the inner side surface.

According to the present invention, prior to the bonding of the side edges 3 and 4 of the blank 2, the side edges 3 are attached to the inner surface of the side edge 3.
A narrow tape 6 of a thermoplastic synthetic resin having an adhesive ability is adhered so as to protrude from the inner side in the circumferential direction to the outer side in the circumferential direction beyond the side edge 3.

As will be described later, both side corners 8 and 9 of the upper edge 7 of the blank 2 are formed when forming the outward flange 10 shown in FIGS. 1, 6 and 7 or a top curl not shown. Cut portions 11 and 12 are formed to prevent the occurrence of a step due to the thickness of the overlapping portion of the side edges 3 and 4, and the entire inner surface of the blank 2 has an adhesive property, a thermoplastic property, and the like. Is formed.

The narrow tape 6 of the thermoplastic synthetic resin having the adhesive ability is welded to the side edge 4 as shown in FIG. 3 when the body 5 is formed, and as shown in FIG. Paper quality end face 1 of blank 2 exposed inside cup
4 completely covers the side edge 3 as shown in FIG. 3 to completely prevent the content liquid from infiltrating from the end face 14.

Conventionally, in order to prevent the content liquid from infiltrating into the paper quality from the end face 14, as an example, the paper quality portion of the side edge 3 is cut into a thin wall as shown in FIG. However, in the present invention, steps such as cutting into a thin wall and folding in two can be omitted.

An inverted dish-shaped bottom wall 16 is provided at the lower end 15 of the body 5.
4 and 5 are fitted as shown in FIGS. 4 and 5 and are wrapped around the inner and outer surfaces by the lower end 15 of the body 5, and are integrally adhered and fixed by the adhesive ability of the waterproof film 13 and the narrow tape 6.

The bonding and fixing portions between the bottom wall 16 and the lower end 15 of the body 5 are bonded and fixed to the inner and outer surfaces of the bottom wall 16 as shown in a schematic enlarged sectional view in FIGS. Between the bonded portion of the side edges 3 and 4 of the body portion 5 and the bottom wall peripheral edge 16A sandwiched by the bottom wall 16;
Due to the thickness of the overlapped portion of the bonded portion 4, the tunnel portion 1 as a gap formed along the entire length of the bonded portion.
7 and 18, the tunnel portions 17 and 18 are filled with the resin of the narrow tape 6 melted by heating and pressing when the lower end 15 of the body portion 5 is bonded to the peripheral edge 16A of the bottom wall. , Sealed. Referring to FIG.
7 and 18 are modeled in large scale to clearly show the structure, and the narrow tape 6 is markedly thinner. However, in the actual paper cup, the tunnel portions 17 and 18 are a fraction of the size shown. By the way, the narrow tape 6 should be understood as having a thickness in the ratio shown in FIG.

The thickness of the narrow tape 6 made of a thermoplastic synthetic resin having an adhesive property is selected in the range of 50 μm to 250 μm, preferably in the range of 70 μm to 150 μm, depending on the thickness of the cardboard forming the blank 2. The water-resistant coating 13 is a polyethylene film having a thickness of 15 μm.
To 40 μm, preferably 25 μm to 35 μm in thickness.

The outward flange 10 shown in FIG.
Are both side corners 8 of the upper edge 7 of the blank 2 shown in FIG.
Due to the presence of the cut portions 11 and 12, unevenness of the flange thickness due to the thickness of the overlapped portion of the bonded portions of the side edges 3 and 4 of the blank 2 hardly occurs as shown in FIG. 7. However, although a tunnel portion 19 as a gap is generated at the abutting portion of the water-resistant coating 13 as shown in FIG. 11, in the present invention, a thermoplastic synthetic resin having an adhesive ability previously bonded to the blank 2 shown in FIG. Narrow tape 6
However, as shown in FIG. 8, the narrow tape 6 is melted by the heating and pressurization accompanying the formation of the horizontal flange 10, and is filled in the tunnel portion 19, so that the tunnel portion 19 is filled. Even if the portion 19 is completely sealed and the separately prepared lid member 20 is adhered in an easily peelable structure, leakage of the content liquid from the tunnel portion 19 does not occur. Also, the bonding portions of the side edges 3 and 4 of the blank 2 in the body 5 are:
As shown in FIG. 3, if the narrow tape 6 is adhered over both side edges 3 and 4, the waterproof property is sufficient, and
There is no need for the sealing of the tunnel part which occurs on the front.

[0019]

According to the first aspect of the present invention, the side edge of the blank forming the body of the paper cup extends over the entire length in the height direction of the side edge occupying the inside when the body is formed. Apart from adding one step of preliminarily adhering a narrow tape of thermoplastic synthetic resin having adhesive ability, extending from the inner side in the circumferential direction to the outer side in the circumferential direction beyond the side edge,
By simply adopting the usual paper cup manufacturing process, the inside of the cup and the outside world are completely shut off, and a paper cup that can completely prevent the infiltration of the liquid content into the paper quality, which is the main material of the cup, is obtained, so manufacturing costs Can be suppressed extremely low, and it is possible to maintain high production efficiency.

According to the second aspect of the present invention, the tunnel formed in the overlapping portion where the both side edges of the blank are bonded to the outward flange formed on the upper edge of the trunk portion is made of a thermoplastic synthetic resin having an adhesive ability. Since the tape is filled with the melted portion of the narrow tape and sealed, the effect of preventing leakage of the content liquid from the outward flange portion and infiltration into the paper quality can be prevented even in a paper cup to which the lid wall is bonded. To play.

According to the third aspect of the present invention, it is possible to select a minimum necessary narrow tape sufficient to fill and seal the tunnel portion in accordance with the thickness of the blank, so that there is no leakage of excess synthetic resin. The effect is that a high-quality paper cup can be manufactured with a minimum necessary material.

[Brief description of the drawings]

FIG. 1 is a reduced development view of one example of a blank.

FIG. 2 is a perspective view of a paper cup formed from the blank shown in FIG.

FIG. 3 is a sectional view taken along line AA in FIG. 1;

FIG. 4 is a sectional view taken along line BB in FIG. 1;

FIG. 5 is a sectional view taken along line CC in FIG. 1;

FIG. 6 is a sectional view taken along line DD in FIG. 1;

FIG. 7 is a cutaway perspective view showing a state before bonding between the overhang flange and the lid wall.

FIG. 8 is a sectional view taken along line EE in FIG. 1;

FIG. 9 is a cross-sectional view similar to FIG. 3, showing an example of a bonding structure at both side edges of a conventional blank.

FIG. 10 is a cross-sectional view similar to FIG. 3, showing another example of a bonding structure at both side edges of a conventional blank.

FIG. 11 is a cross-sectional view similar to FIG. 8, illustrating an example of a conventional bonding structure between a projecting flange and a lid wall.

[Description of Signs] 1 Paper cup 2 Blank 3, 4 Side edge 5 Trunk 6 Narrow tape 10 Outward flange 15 Lower end of trunk 16 Bottom wall 16A Bottom wall periphery 17, 18, 19 Tunnel

Claims (3)

[Claims] 1. The body of a cardboard made of cardboard is formed by molding a blank into a cylindrical shape, and overlapping and adhering both side edges, wherein the cup is one of the superimposed and adhered side edges. A heat having an adhesive ability that has been adhered to the inner side edge of the inner surface of the cup over the entire length in the height direction of the cup, extending from the inner side in the circumferential direction of the side edge to the outer side in the circumferential direction beyond the side edge. A narrow tape of a plastic synthetic resin is welded over at least the overlapped portion where the both side edges of the blank are adhered on the inside of the body, and the narrow tape is bonded between the bottom wall periphery and the body bottom edge. In the portion, due to the thickness of the overlapped portion where the both side edges of the blank are adhered on the inner side of the body portion, the adhesive molding of the adhesive portion is performed on a tunnel portion which is a gap formed along the entire length of the adhesive portion. Melting by heating and pressing A paper cup, which is melted and filled to seal the tunnel. 2. A narrow tape of a thermoplastic synthetic resin having an adhesive ability is welded so as to cover an overlapped portion where both side edges of a blank in an outward flange formed on an upper edge of a body portion are bonded. The paper cup according to claim 1, wherein the paper cup is filled with a tunnel part formed in the overlapping part, and the tunnel part is sealed. 3. A thin tape having a thickness of 50 μm to 250 μm.
3. The paper cup according to claim 1, wherein the paper cup is selected and adhered in the range of μm according to the thickness of the blank.