Non-returnable Packing Containers

Abstract

A non-returnable packing container comprises at least one substantially plane end wall in which a pouring opening is provided. An inner cover strip is fixed against the inner surface of the end wall over the pouring opening, and an outer, tear-off cover strip is secured over the pouring opening at the outer surface of the end wall, the cover strip being provided with tear-perforations extending along each side of the pour opening.

Description

The present invention relates to a non-returnable packing container comprising at least one substantially plane end wall, a pouring opening provided in the said end wall, an inner cover strip which is fixed against the inside of the said end wall over the pouring opening, and an outer cover strip which is fitted over the pouring opening against the outside of the end wall.

In the technique of packing non-returnable packing containers are often used for the packing of liquid products and here in particular for pressurized liquid products such as beer, refreshing beverages and the like. These known packing containers as a rule have a cylindrical body and two end plates of metal, which are folded into the cylindrical body. The packing continers are often provided with an opening device which consists of a weakened part of the one end plate, which usually is made of aluminium sheet. In the said weakened part is fixed a pull ring by means of which the opening device is broken and ripped off for the purpose of creating a pouring opening, through which the liquid contents can be made accessible.

These known packing containers have the disadvantage that they are relatively expensive and moreover heavy. It has also been found that the packing containers of this type most often have an end plate and a container body of sheet steel, whilst on the other hand the end plate which comprises the opening indication has to be manufactured of a softer metal, e.g., aluminium, which means that packing containers of this type cannot be re-used in the form of iron scrap. A further disadvantage inherent in these packing containers is that they are environmentally unsound, since they remain behind in nature a very long time before they rust through, and during that time they constitute, because of their sharp edges, a great danger for animals and human beings.

The abovementioned disadvantages are overcome by a packing container in accordance with the invention, which packing container has at least one preferably plane end wall which has one pouring opening punched out beforehand, which on the inside of the packing container is covered by an inner cover strip and on the outside of the packing container is covered by an outer cover strip, and which is characterized in that the said outer cover strip is fixed to the said inner cover strip in the area of the pouring opening by a strong seal joint, that the outer cover strip is fixed to the outside of the end wall along zones on both sides of, and at a distance from, the edge of the pouring opening and that the outer cover strip has tearing perforations which are located on both sides of the pouring opening between the edge of the pouring opening and the said sealing zones, along which the outer cover strip is fixed to the outside of the end wall.

The invention will be described in the following with reference to the enclosed diagrammatic drawing, in which

FIG. 1 shows a partly cut away perspective view of a packing container in accordance with the invention,

FIG. 2 shows an opened packing container, and

FIG. 3 shows a cut away view of the end wall of the packing container provided with opening device.

Although the invention can be applied to all packages of drum character it is assumed in the special embodiment shown here that the package is of the type as shown in FIG. 1 and thus consists of a thin inner plastic lining 2 with a dished base, a surrounding supporting shell 3 of a rigid, only slightly extensible material, e.g., cardboard, which surrounding shell is in supporting contact with the cylindrical part of the inner plastic lining 2. The shell 3 extends past the outer part of the plastic lining 2 and may thereby serve as a foot for the package 1. The end plate 4 consists in the case described here of a metal lid 4 folded on preferably made of sheet steel, which would be the cheapest and strongest material, and in the end plate 4 a pouring opening 5 is punched out.

As can be seen from FIG. 3, the pouring opening 5 on the inside of the end plate 4 is covered by a cover strip 10, which along the area 12 around the pouring opening 5 is fixed to the inside of the end wall 4 by a relatively strong seal joint. Against the outside of the end plate 4 is arranged another outer cover strip 6, which, as can be seen from FIGS. 1 and 2, is sealed to the outside of the end wall 4 along the sealing zones 7 and 9, along which sealing zones the cover strip 6 has very good adhesion against the end wall 4. In the area of the pouring opening 5 the cover strips 6 and 10 are joined to one another by means of a strong seal joint 11. This seal joint must be so strong that the inner cover strip 10 is ripped up when the outer cover strip 6 is lifted upwards with the help of the pull lug 14, without there being any risk that the seal joint between the cover strips 6 and 10 is broken instead. The seal can be realized with the help of an adhesive, such as glue or heat-activatable paste, so-called hot melt, or the seal may also be achieved by a surface fusion between thermoplastic coats on the cover strip 6 as well as on the cover strip 10. The cover strips may preferably consist of metal foil, e.g., aluminium foil, which is coated with plastic or with any adhesive.

As can be seen from FIG. 1, the outer cover strip 6 is provided with two tearing perforations 8 which are arranged on both sides about the pouring opening 5. The tearing perforation 8 may consist either, in the manner as shown in FIG. 1, of a series of continuous perforations of the cover strip 6, but it is also possible to realize the tearing indication as a continuous weakening of the cover strip 6, e.g., in that in the cover strip 6 a score is cut which extends down to for example half the thickness of the cover strip. The perforation lines or weakening lines 8, as can be seen, are arranged between the edges of the pouring opening 5 and the sealing zones 7, and they extend from the outer part of the cover strip 6 at the pull lug 14 up to the transverse sealing zone 9.

To prevent the formation of air pockets between the cover strip 6 and the end plate 4 and within the area of seal between the cover strips 6 and 10 when the outer cover strip 6 is applied to the end wall 4, it is important to ensure that a channel communicating with the outer atmosphere is formed between the inside of the cover strip 6 and the outside of the end wall 4. Such a channel is achieved if the sealing of the outer cover strip 6 is realized in such a manner as has been described, namely by two sealing zones 7 on either side of, and at a distance from, the pouring opening 5 and a transverse seal 9 which is arranged substantially at a right angle to the earlier mentioned sealing zones 7 and transversely over the perforation lines 8, whilst on the other hand the outer cover strip 6, at the part which terminates in the pull lug 14, is not sealed to the end wall 4.

When the packing container is to be opened the pull lug 14 of the outer cover strip 6 is gripped between the fingers and is pulled upwards-backwards, whereby the stress on the tearing perforation becomes so great that the outer cover strip 6 will break along the perforation lines 8. When the tearing off of the outer cover strip 6 continues, a point is reached first at the front part of the pouring opening 5, where the cover strips 6 and 10 are joined to one another in a strong bond. In this phase of the tearing up the outer cover strip must be pulled upwards with such a force that the inner cover strip 10 breaks, whereupon the tearing continues along the perforation lines 8 with simultaneous tearing up of the part of the inner cover strip 10 exposed in the pouring opening 5. When the tearing up of the outer cover strip 6 has gone on so long that the whole pouring opening 5 is freed, the tearing may be continued until the transverse seal 9 is reached, it being assumed that the seal 9 is so strong that a further tearing up of the outer cover strip 6 cannot be performed without the use of force. As can be seen from the description and from FIG. 2, which indicates the course of the tearing up, it is only the central middle strip 15 of the outer cover strip 6 which is torn up, whilst on the other hand the sealed portions outside the tearing perforations 8 continue to be fixed to the end wall 4.

The advantage of the opening indication in accordance with the invention is that it is easy to tear up, since at the tearing off of the outer cover strip 6 only the resistance has to be overcome which is offered by the tearing perforation 8, and naturally of the inner cover strip 10 which is to be broken up. However, the inner cover strip 10 can be manufactured of a relatively thin foil which can readily be ripped up.

If it is desired that the pouring hole 5 should be laid open permanently it it unsuitable to provide the transverse seal 9, but instead the central strip 15 of the cover strip 6 may here be removed completely and thrown away. If it is desired on the other hand to allow the package to be re-closed to a fair degree by covering up the pouring hole 5, the sealing zone 9 serves the purpose of stopping the tearing off operation of the central middle strip 15 of the cover strip 6 when the tearing has attained the transverse sealing zone 9, and the possibility exists then to cover up again the pouring opening 5 by folding back the torn up part of the cover strip 6, the inside of which can be provided with an adhesive coating which gives a readily breakable re-closure.

The embodiment of the invention described here intends only to illustrate a specially suitable form of realization, and it is possible of course within the framework of the concept of the invention to modify the appearance of the pouring opening as well as the material composition of the cover strips and the general design of the packing container.

Claims

I claim:

1. A non-returnable packing container having at least one substantially plane end wall, a pouring opening provided in said end wall, an inner cover strip affixed to the inside of said end wall to cover the pouring opening, a longitudinal outer cover strip disposed over the pouring opening against the outside of said end wall, said outer cover strip being affixed to said inner cover strip in the area of the pouring opening by a strong seal joint, said outer cover strip being affixed to the outside of said end wall along longitudinal sealing zones on opposed sides of and spaced from the edge of the pouring opening, said outer cover strip having two substantially parallel lines of perforations located on opposed sides of the pouring opening between the edge of the pouring opening and said longitudinal sealing zones, said longitudinal outer cover strip being affixed by a strong seal joint at one end thereof to said end wall along a sealing zone which extends transversely of the lines of perforation, whereby said outer cover strip will normally remain affixed to said end wall after opening the packing container by lifting said outer cover strip and tearing along said lines of perforation to remove the inner cover strip in the area of the pouring opening.

2. A packing container as claimed in claim 1 wherein the area between the outside of the end wall and the inside of said outer cover strip immediately surrounding the sealed area between said inner and outer cover strips within the pouring opening is in communication with the surrounding atmosphere.

3. A packing container as claimed in claim 1 wherein said cover strips consist of a laminate material comprising a metal foil layer and at least one layer of adhesive material.