JPH04239441A - Sealing lid made of cardboard and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide a lid for a can or can-shaped container which can be made of corrugated cardboard, and which has a necessary strength and especially a necessary stability in spite of paper products. CONSTITUTION: A stable ring 4a reinforcing the ridge of a flange 3a circumferentially formed in an overlap type lid 2a or a fitting lid is provided. The stable ring 4a is stuck and/or welded on the inside face and/or the outside face of the flange 3a formed at the circumference.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing lid made of cardboard for a can or can-like container, and a method for manufacturing the same.

0002

BACKGROUND OF THE INVENTION Closing lids of this type are known as so-called overlapping lids or mounting lids. The present invention relates to both of these closures.

Cans made of cardboard for containing foodstuffs and the like are widely known today. Containers of this type are coated with a thin layer of plastic so that they do not decompose in the garbage and therefore do not pollute the environment in the long term. In other words, this type of container is designed to be compatible with its environment.

[0004] To date, the lids of containers of this type have been composed entirely of plastic. This is due to the impossibility of manufacturing a geometrically stable lid from cardboard. In this case, it must be borne in mind that the lid is attached to the can long after manufacture, ie after the can has been filled with filling, for example in a filling factory. In the meantime, deformation of the lid cannot be prevented. Additionally, environmental factors such as temperature and humidity act on the lid, causing the lid to deform.

[0005] Such lids therefore have a clear environmental impact and create waste disposal problems. However, if the sealing lid is made of the same material as the can body, ie cardboard, there is no need to treat the lid separately from the can.

From German Patent No. 251424,
Capsule caps for containers are known which are manufactured from cardboard and have a spherically reinforced neck and a likewise reinforced recess. At its lower end, this capsule cap has a ring-shaped edge that is bent somewhat outwards. The lower part of the capsule cap is thereby provided with a material that is resistant and capable of withstanding the tensions that occur when the capsule cap is attached to the bottle and compensate for deformations of the lower part of the capsule cap during this attachment. Folding the capsule cap in this way was not actually known, but such bending does not prevent deformation for long periods of time. This is because cardboard has a certain memory ability, and edges that are folded outward tend to return to their original position. Such recovery based on memory ability is also strengthened by humidity and temperature.

[0007]

OBJECT OF THE INVENTION The object of the invention is to provide a container for cans or can-like containers which can be manufactured from cardboard and nevertheless have the necessary strength and, in particular, the necessary stability. It is to provide a lid.

[0008]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a sealing lid with a stabilizing ring that reinforces and goes around the edge of the flange of the overlapping lid or the attached lid, and The stabilizing ring is fixed to the inner and/or outer surface of the surrounding flange by adhesion and/or welding, and the manufacturing method thereof includes making a circular pressed blank made of cardboard; producing a groove by pressing a suitable tool into the edge area; forming a pot-shaped lid from a circular pressed blank with grooves formed in the edge area; The stabilizing ring is bonded or welded to the area opposite the stabilizing ring edge.

[0009]

Embodiments Next, embodiments of the present invention will be described with reference to the accompanying drawings.

In FIG. 1 a can 1 is shown. The can 1 has an overlapping lid 2. This lid 2 is provided with a circumferential flange 3 directed downwards. Lid 2
overlaps the outer surface of the upper edge of the can 1 by means of this downwardly directed flange 3. The downwardly directed flange 3 carries a tearing side plate 22. In this embodiment, therefore, the lid 2 can be opened by operating the tear-off side plate 22 and thus by dividing the flange 3 into two parts.

[0011] In manufacturing the lid described below, for example, the overlapping type lid 2 described above, a circular press material 20 of cardboard is the starting point (FIG. 2). The circular pressed blank 20 is provided with grooves 21 at least in its edge region. The groove 21 prevents the flange 3, which is later bent, from returning.

In order to make a lid 2 of this type, which is made of cardboard and therefore normally unstable in shape, additionally stable in shape, according to FIG. 3 the circumferential flange 3a of the lid 2a is bent inwards. , forming a stabilizing ring 4a. This stabilizing ring 4a is pressed onto the inner surface of the downwardly directed flange 3a by applying heat and is fixed by melting the thin plastic layer. As a result, the lid shown in FIG. 4 is obtained. Instead of applying heat to weld the plastic layers that abut each other, adhesives can also be used. The result is an adhesive layer instead of a plastic layer.

As can be seen from FIGS. 5 and 6, the flange 4
It is also possible to weld a widely, that is, to reach a high position on the inner surface of the flange 3a. As a result, stability ring 4
The upper part of a or 4b largely protrudes inward. In this case, as can be seen from FIG. 13, stability is obtained for the lid 2a. Once the lid 2a is stabilized, it can be particularly firmly clamped onto the can 1a, ie the lid 2a can be configured as a stable lid, so that unintended openings can be prevented.

In the embodiment shown in FIGS. 7 and 8, the downwardly directed and circumferential flange 3c is bent inward, as in the previous embodiment. The reinforcing ring 5 is inserted into the U-shaped space thus formed. This reinforcing ring 5 is fixed to the surrounding flange 3c by applying heat and thus to the inner surface of the bent edge of this flange 3c. This allows lid 2
A stability ring 3c of c is formed. This stability ring 3c
can also be formed by welding or gluing, as in the embodiments of FIGS. 5 and 6.

In the embodiment shown in FIGS. 9 and 10, an additional stabilizing ring 4b is provided. This additional stabilizing ring 4b has a J-shaped design in the example shown. The short arms of the J-shaped stabilizing ring 4b are directed downwardly and rest on the inner surface of the circumferential flange 3b, and the longer arms rest on the outer surface of the flange 3b. In this embodiment as well, the flange 3b is fixed to the stabilizing ring 4b, for example by heat treatment.

In the embodiment shown in FIGS. 11 and 12, 11 is a sealing lid. The sealing lid 11 consists of a bottom part 12 and an edge part 3 perpendicular to the bottom part 12. FIG. 11 shows the edge 13
that the free edge of is bent outwards, i.e. edge 1
It is shown that a U-shaped flange 15 is formed in the upper region of 3. When this U-shaped flange 15 is pressed from the outside to the inside, this U-shaped flange 15 comes into contact with the outer surface of the edge 13. Since the material has a thin plastic coating, the flange 1 can be heated by heat treatment.
5 can be glued to the outer surface of the edge 13 to form a stabilizing ring 14 as illustrated in FIG. This stabilizing ring 14 ensures that the folded edge 1
3 is not restored, ie the closing lid 11 is formed so that it can be stacked on the filling can for a long period of time in the filling factory after manufacture.

When stacking the sealing lid 11, the stabilizing ring 14 is stacked on top of the upper ridge of the can, thus forming a stop. At the same time, this stabilizing ring 14 also serves as a grip, so that the sealing lid 11 can be easily removed.

Although the drawings show a circular sealing lid, it goes without saying that the sealing lid may have a polygonal shape.

FIG. 13 shows an example of the use of a can 1a with a lid 2a, which is constructed as a stable lid with a tear-off side plate 22 by means of a projecting stabilizing flange 4a.

Next, embodiments of the present invention will be listed.

(1) The lower edge of the circulating flange (3a) is bent inward and fixed to the inner surface of the flange (3a) by adhesive and/or welding to form a stabilizing ring (4a). The airtight lid according to claim 1.

(2) The lower edge of the circumferential flange (3a) is bent inward, and the reinforcing ring (5) is inserted into the U-shaped space formed by this, and the reinforcing ring (5) is inserted between the bent edge and the reinforcing ring. Closing lid according to claim 1, characterized in that the ring (5) is fixed by adhesive and/or welding to the inner surface of the flange (3c) and forms a stabilizing ring (4c).

(3) J fixed by adhesive and/or welding to the inner and outer surfaces of the circulating flange (3b)
Closing lid according to claim 1, characterized in that a stabilizing ring (4b) in the shape of a letter or a letter U is provided.

(4) The free edge of the edge (13) of the lid (11) is bent outward and fixed to the outer surface of the edge (13) by adhesive and/or welding;
The airtight lid according to claim 1.

[0025]

According to the present invention, the upwardly or downwardly directed flange of the sealing lid is fixed so as to abut against the outer surface or the inner surface of the flange, depending on whether the lid is an overlap type lid or an attached lid. It is proposed that a stabilization ring be provided. Since both the lid and the can are provided with a thin plastic coating, the thin plastic coatings are brought into contact with each other by applying heat to the region of the surrounding stabilizing ring edge or flange and applying a corresponding pressure effect. can be melted. The stabilizing ring edge is thus fixed to the surrounding conventional flange. Such a simple construction provides high stability of the lid.

[0026] If the can and lid are provided with a thin plastic coating, welding is applied, but if the thin plastic coating is not provided, it is of course possible to substitute a corresponding adhesive layer. It is. An equivalent effect can be obtained by gluing the stabilizing edge and flange together.

The height of the adhesive or weld between the flange and the stabilizing edge or the stabilizing ring can be selected arbitrarily, so that the somewhat protruding inner part of the folded flange, ie of the stabilizing ring, is provided with an opposing support. A sealing lid is provided that forms a member and the opposing support member ensures that the overlapping lid is supported on the can. On the other hand, the lid cannot be removed from the container without damage, so that tasting and inspection of the container contents by unauthorized persons is no longer possible.

[Brief explanation of the drawing]

1 is a perspective view of a can with an overlapping lid; FIG.

FIG. 2 is a diagram showing a circular press material for producing a lid.

FIG. 3 is an explanatory diagram for explaining the first work step of manufacturing the lid of the first embodiment.

FIG. 4 is an explanatory diagram for explaining the second work step of manufacturing the lid of the first embodiment.

FIG. 5 shows a bonded or sealed stable edge.

6 shows a stable edge glued or sealed at a different height than in the embodiment of FIG. 5; FIG.

FIG. 7 is an explanatory diagram for explaining the first work step of manufacturing the lid of the modified example.

FIG. 8 is an explanatory diagram for explaining a second work step of manufacturing the lid of the modified embodiment of FIG. 7;

FIG. 9 is an explanatory diagram for explaining the first work step of manufacturing a lid of another modified example.

FIG. 10 is an explanatory diagram for explaining a second work step of manufacturing the lid of another modified embodiment of FIG. 9;

11 shows a first manufacturing step of a mounting lid with a stabilizing edge; FIG.

FIG. 12 shows a second manufacturing stage of the mounting lid with stabilizing edge;

FIG. 13 is a perspective view of the can with the lid attached.

[Explanation of symbols]

2, 2a, 2b, 2c Overlap type lid 3, 3a, 3b, 3c, 13 Flange 4a, 4b, 4c, 14 Stability ring 1
1 Mounting lid

Claims (2)

[Claims] Claim 1: An airtight lid made of cardboard for a can or can-like container, comprising an overlapping lid (2, 2a, 2b).
, 2c) or the surrounding flange of the mounting lid (11) (
A stabilizing ring (4a, 4b, 4c, 14) is provided which reinforces the edges of the flange (3, 3a, 3b, 3c, 13) and surrounds the flange (3, 3a, 4b, 4c, 14). , 3a, 3b, 3c, 13) by adhesive and/or welding. 2. The method of manufacturing a sealing lid according to claim 1, comprising: a) producing a circular pressed material (20) made of cardboard;
b) producing grooves (21) by pressing a suitable tool into the edge area of the circular pressed stock (20), c)
) Circular pressed blank with grooves (21) formed in the edge area (
20) molding a pot-shaped lid (2, 2a, 2b, 2c, 11) from d) gluing or bonding the circumferential stabilizing ring edge with the area of the lid edge opposite the stabilizing ring edge; A method for manufacturing a hermetic lid, characterized by welding.