Technical Field

The invention generally relates to the field of packaging technology. More particularly, the invention relates to an opening device for a package for liquid food. Further, it is presented a package for liquid food comprising the opening device, a method for attaching the opening device to the package, and an apparatus for performing the method.

Background of the invention

Packages for food are considered very important by retailers and producers of liquid food products. One important part of the packages is the opening device, which should be easy to handle for the consumers.

More particularly, the opening device should be easy to open. The opening device should also be tamper evident such that an opened package may be distinguished from a non-opened package, thus making it possible for the consumer to choose a non-opened package and in turn be sure that the content of the package is safe to consume. Further, it is often requested that the opening device is re-closable, especially for larger packages not consumed at once. In order to meet these requirements different types of opening devices have been developed.

For a so-called carton gable top package an opening device is often applied in a hole in one of the two sections forming a roof of the carton gable top package. The opening device for carton gable top package can comprise a spout part comprising a threaded section and a spout flange and a cap part comprising a cap portion, a tamper ring portion and a tamper ring flange, wherein the cap portion and the tamper ring portion is attached to each other in an interface area provided with a weakening line and wherein the tamper ring flange is attached to the tamper ring portion. The cap part is screwed onto the spout part before these are inserted in the hole from the inside of the package such that the spout flange and the tamper ring flange are placed against the inside of the package. Thereafter, the spout flange and the tamper ring flange are welded to the inside of the package using ultrasonic sealing. Such a solution is disclosed in EP2032451 .

A problem with the opening devices presented above is that they must be designed in such a way that a force required for tearing off the cap portion is as small as possible in order to make it possible for as many people as possible to be able to open the package, but at the same time as large as possible in order to prevent that the tamper ring portion and the cap portion is separated by mistake.

Summary

In view of the problem stated above it is an object to provide an opening device which is easy to open at the same time as a risk that the cap portion is separated from the tamper ring portion is reduced.

Generally, it has been realised that the problem may be solved by only attaching the spout flange to the inside of the package and thereby making it possible for a tamper ring portion flange to rotate around a rotational axis coinciding with a rotational axis of the cap portion. An implication of this is that the cap portion will be separated from the tamper ring portion due to a vertical force successively built up as the cap portion is unscrewed. Thus, due to that the threading of the spout is utilised for building up the vertical force, the opening device can be designed such that weak persons are able to break a more roboust weakening line than if the weakening line was to be torn off as disclosed in prior art.

According to a first aspect it is provided an opening device comprising a spout having a threaded section and a spout flange, said spout flange having a spout flange radius, a cap and tamper ring combination having a cap portion and a tamper ring portion, said cap and tamper ring combination being provided with a weakening section in an interface between said cap portion and said tamper ring portion, said cap portion being provided with a threaded section arranged to interact with said threaded section of said spout, said tamper ring portion being provided with a tamper ring flange, said tamper ring flange having a tamper ring flange radius, wherein said spout flange radius is greater than said tamper ring flange radius, such that when said opening device is inserted in a hole of a package and said spout flange is attached to said package, said cap and tamper ring combination is rotationally arranged between said spout flange and said package.

Further, a peripheral section of said spout flange may be provided with a projection. A height of said projection may be greater than a width of said tamper ring flange.

The spout flange may be provided with at least one hole.

The spout flange may be attached to said package by welding said spout flange to said package.

The cap and tamper ring combination may be made of polyethylene

(PET).

According to a second aspect it is provided a package for liquid food comprising an opening device according to the first aspect.

According to a third aspect it is provided a method for attaching an opening device to a package, said opening device comprising a spout having a threaded section and a spout flange, said spout flange having a spout flange radius, a cap and tamper ring combination having a cap portion and a tamper ring portion, said cap and tamper ring combination being provided with a weakening section in an interface between said cap portion and said tamper ring portion, said cap portion being provided with a threaded section arranged to interact with said threaded section of said spout, said tamper ring portion having a tamper ring flange, said tamper ring flange having a tamper ring flange radius, wherein said spout flange radius is greater than said tamper ring flange radius, said method comprising placing said opening device, having said cap and tamper ring combination applied on said spout, in a hole in a package, said hole having a radius less than said spout flange radius and less than said tamper ring flange radius, and attaching said spout flange to said package, such that said cap and tamper ring combination is rotationally arranged between said spout flange and said package.

The spout flange may be attached to said package by welding said spout flange to said package. According to a fourth aspect it is provided an apparatus arranged to perform the method according to the third aspect.

The apparatus may comprise a cap placing device arranged to place said opening device, having said cap and tamper ring combination applied on said spout, in a hole in a package, said hole having a radius less than said spout flange radius and less than said tamper ring flange radius, and a cap attachment device arranged to attach said tamper ring flange to said package, such that said cap and tamper ring combination is rotationally arranged between said spout flange and said package.

The features of one of the aspects may be shared with the other aspects.

Brief description of the drawings

The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, wherein:

Fig 1 illustrates a gable top package provided with an opening device.

Fig 2 illustrates a cross-section of a general example of a cap and tamper ring combination.

Fig 3 illustrates a cross-section of a general example of a spout.

Fig 4 illustrates a cross-section of a general example of a hole in a package.

Fig 5 illustrates a cross-section of the cap and tamper ring combination applied onto the spout and placed in the hole of the package.

Fig 6 illustrates a cross-section of the cap and tamper ring combination applied onto the spout and placed in the hole of the package, wherein the spout flange is attached to the package.

Fig 7 illustrates the cross-section illustrated in fig 6 and a

corresponding top view.

Fig 8 illustrates a cross-section of the cap and tamper ring combination applied onto the spout, wherein a process of unscrewing the cap and tamper ring combination from the spout has been started. Fig 9 illustrates a cross-section of the cap and tamper ring combination applied onto the spout, wherein the process of unscrewing the cap and tamper ring combination from the spout has reached a stage where the cap and tamper ring combination has been separated into two parts.

Detailed description

Fig 1 illustrates a gable top package 100 commonly used for e.g. milk and juice in many countries. The gable top package 100 comprises a body 102 often made of a blank in turn made of a carton-based laminate. As illustrated, the package 100 may be equipped with an opening device 104 making it easier to open the package and possible to reclose the package.

The blank may comprise a pre-made hole. During the production of the package the opening device 104 may be inserted in this pre-made hole such that a flange of the opening device may be attached to the inside of the package.

As illustrated in fig 2, the opening device may comprise a cap and tamper ring combination 200 comprising a cap portion 202 and a tamper ring portion 204 connected to each other in a weakening section 206. The weakening section 206 may be a perforation or other means for making it possible to separate the cap portion 202 from the tamper ring portion 204. The cap portion 202 may be provided with threadings or other similar means, such as a cam curve, to make it possible for the cap portion 202 to interact with another device having corresponding threadings or corresponding similar means. The tamper ring portion 204 may be provided with a tamper ring portion flange extending substantially radially outwards.

As illustrated in fig 3, the opening device 104 may further comprise a spout 300. The spout 300, in turn, may comprise a threaded section 302 provided with threadings or other similar means for interacting with the cap portion 202, such that a consumer can screw and unscrew the cap portion 202. Further, the spout 300 may comprise a spout flange 304 which optionally may be provided with a projection 306 at its peripheral end.

Fig 4 illustrates a part of a blank 400 comprising a hole 402. The blank 400 may be made of a carton-based laminate comprising a carton layer 404, an outer plastic layer 406 and an inner plastic layer 408. In order to get an improved light barrier a layer comprising an Aluminum foil may be added. Further plastic layers may be added in order to achieve improved aseptic conditions, roboustness or cost efficiency.

Before attaching the opening device 104 to the body 102 the cap and tamper ring combination 200 can be applied onto the spout 300, e.g. by screwing the cap and tamper ring combination 200 onto the spout. After having applied the cap and tamper ring combination 200 onto the spout 300, the opening device 102 can be inserted from the inside of the package 100, as illustrated in fig 5.

Next, the opening device 104 can be attached to the body 102 by attaching the spout flange to the inside of the body 102, e.g. by welding them together, as illustrated in fig 6. In order to ensure that the tamper ring portion flange is free to rotate when the cap portion 202 is unscrewed the spout flange may be provided with a projection. To further ensure that the tamper ring portion flange is free to rotate a height of the projection may be greater than the thickness of the tamper ring flange. Further, although not illustrated, in order to reduce the friction and hence make it easier for the cap and tamper ring portion 200 to rotate the tamper ring flange may be provided with holes.

As illustrated in fig 7, due to that a diameter of the tamper ring flange is larger than a diameter of the hole in the package, the tamper ring portion 202 will be held back by the hole when the cap and tamper ring combination 200 is unscrewed resulting in that the cap portion 202 and the tamper ring portion 204 will be separated.

Fig 8 illustrates a cross-section of the package when the cap is being unscrewed. Unlike present opening devices, where the tamper ring portion flange is welded to the package and/or the spout flange and hence not capable of rotate with respect to the spout flange and the package, tensions can be built up between the tamper ring portion and the cap portion, thereby making it possible for a user to make use of the threadings for building up a force for separating the cap portion from the tamper ring portion. Fig 9 illustrates a cross-section of the package where the cap portion and the tamper ring portion has been separated from each other.

In order to improve the Oxygen Transmission Rate (OTR) of the packages the cap and tamper ring combination 200 may be made of polyethylene (PET) or any other material which is formable and has good OTR properties. Alternatively or in combination with the cap and tamper ring combination 200 made of PET, in order to improve the OTR properties of the packages, the spout 300 may be made of PET, or any other material which is formable, has good OTR properties and that can be attached to the package efficiently.

Since the cap and tamper ring portion 200 is neither attached to the package nor the spout 300 no consideration has to be taken as to whether the material can easily be attached, e.g. by using welding, or not to the spout and/or the package. This means that the cap and tamper ring combination 200 can be made of a material that has good OTR properties even if this material is not suitable for being attached to the spout and/or the package.

Further, if a more cost efficient package is requested and good OTR properties is not a necessity, since the cap and tamper ring portion 200 is not attached to the spout and/or the package, a low cost material of the cap and tamper ring portion 200 may be chosen irrespective of whether this material can easily be attached to the spout and/or the package.

In the same way, since the tamper ring flange is not attached, the cap and tamper ring portion 200 may be made of a material with good light barrier properties irrespective of this material is suitable for being attached to the inside of the package or the spout flange.

The invention has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.