Patent Application
20210331828
The invention relates to a composite pack, in particular a parallelepipedal cardboard/plastic composite pack for pourable products, having an elliptical laminated hole which is provided in the composite pack gable, with an elliptical main axis and an elliptical minor axis, and a pouring element, comprising a basic body, a cutting element movably guided in the basic body and having the shape of a hollow cylinder with a cylinder outer diameter and a resealable screw cap, wherein the screw cap serves for opening the composite pack for the first time by activation of the cutting element, which thus forms a pouring opening in the region of the laminated hole and wherein first guidance means configured on the cutting element interact with second guidance means configured on the basic body. The invention also relates to a cardboard/plastic composite material and a blank made from this, and a pouring element for use with such a composite pack.
Composite packs, comprising a cardboard/plastic composite material pack (hereinafter referred to as pack) and a pouring element, are known in practice in a large number of variations. The precise layer structure of the composite material may vary according to requirements but comprises at least one carrier layer made of cardboard and top layers in plastic. A barrier layer (such as aluminium, polyamide or ethylene-vinylalcohol-copolymer) may also be necessary in order to ensure an enhanced barrier effect for aseptic filling products against gases and in the case of aluminium against light also.
Such a pack is normally produced in one of two types of packaging machines. In the first alternative a continuous web of sterilised composite material is formed into a tube and sealed, after which it is filled with similarly sterilised filling product and then sealed and cut at uniform intervals transversally thereto. The resulting, “pillow packs” are then formed along the pre-folded edges into parallelepipedal packs. The sealed seam that results in the gable region during transversal sealing is normally referred to as a gable seam. The other variant uses blanks made of composite material, which are first formed into carton sleeves by sealing along the longitudinal seam and then formed on mandrels into semi-finished packs with an opening on one side, sterilised, filled and finally sealed and end-formed.
For ease of use during pouring and to allow resealing, pouring elements are also applied to the gable of the composite pack. The most commonly-used of these pouring elements come in three parts and comprise a basic body, adhering to the outer side of the composite material, a screw cap and a hollow cylinder-shaped cutting element, which opens the previously gas-tight pack for the first time and thus forms its pouring opening. These pouring elements are usually applied by separate machines, either with the help of hot melt adhesives or by welding of the basic body to the outer plastic coating.
Since the composite material, due to its stable layer structure, is extremely difficult to separate, the composite pack is normally suitably adapted. The pouring element with its cutting element could be designed to be sufficiently stable to easily cut through the entire composite material. But this can mostly be ruled out on cost grounds. It is therefore normal for the opening region to be prepared in such a way that a weakening arises there, which is mainly known in two different designs. Firstly, what are known as weakening lines are positioned in the outer layers of the composite materials, which are matched to the geometry and size of the cutting elements to be used and allow easier separation. Secondly, the weakened region can be designed as what is known as a “laminated hole”. The first two options have the disadvantage that in each case open cardboard edges result, which during pouring come into direct contact with the filling product. This can lead to cardboard fibres in the product and to impairment of the taste thereof. Therefore, a laminated hole is normally the preferred solution.
A laminated hole, as described in EP 2 528 731 A1 by the applicant is formed during the composite material production. Here, a hole is stamped in the cardboard carrier layer, so that following coating with the plastic top layers a localised weakening in the composite material results. It therefore comprises all the normal layers of the composite without the stamped cardboard carrier layer: the top layers, a possible barrier layer and if necessary laminating layers and adhesive layers. For the purpose of this invention, the size of the laminated hole intended to be defined as that of the stamped hole in the cardboard carrier layer, and not the point at which the other layers meet.
In practice it has been found that this type of packaging weakening cannot be placed too close to the pack edges or the gable seam. In particular, the very high sheet speeds during lamination of the composite material lead to such restrictions. So, depending on the dimensions of the gable region of the pack, there is a certain size of the laminated hole, that cannot be exceeded. The restriction here is mostly the width of the pack gable, thus the distance between the gable seam and the pack edge parallel thereto. On the other hand, the later gable seam during the lamination process is in the direction of movement, which in turn is associated with increased tolerances of the hole in this longitudinal extension. However, since the width of the pack gable is transversal to the direction of movement, in the direction of movement, the hole—where it is not restricted by edges that are too close and where it has higher tolerances—has a longer design than transversally thereto. This results in a roughly elliptical hole shape with the elliptical main axis along the direction of movement and the elliptical minor axis transversally thereto. Such an elliptical hole shape can be designed as an elongated hole.
However, in other production systems, the later gable seam is transversal to the direction of movement, preventing the abovementioned design and resulting in a round hole shape with a radius that is just as restricted by the width of the gable as the minor axis of the ellipse in the first example.
EP 1 088 765 A1 describes a pouring element and an associated generic composite pack. The basic body, screw cap and cutting element together form a pouring element which during first operation separates the laminated hole in a large region and pushes the unpenetrated part of this to the side, to create a pouring opening. Here, the cutting element is guided in its movement by a thread on its outer side in the basic body and is actuated by the screw cap.
Basically, a larger cutting element is always desirable, since this allows a larger volume flow during pouring which, in turn, leads to greater speed and control, in particular avoidance of “gurgling”. Obviously, though, there are a number of different products and applications. This means that a wide choice of different pouring elements in different sizes is available. The interface in the form of the laminated hole, which is invisible to the consumer, is only relevant to this choice to the extent that the cutting element can easily separate this while the basic body is always applied cleanly outside of this. A new design of the laminated hole always comes with investment costs in the form of new stamping tools and impression cylinders with adapted print images, as well as potentially high production costs of recalibrating the production processes.
On this basis, the object of the present invention is to redesign and develop the abovementioned composite pack already described in more detail in such a way that while retaining an already existing variant of a laminated hole the greatest possible outflow diameter can be created, or that the system of laminated hole and cutting element is optimised beyond its normal limits.
The object is achieved with a composite pack with the features of the invention in that the cylinder external diameter is at least as big as the length of the elliptical minor axis. This leads to the cutting line of the cutting element running along or even outside the edge of the laminated hole and therefore the laminated hole being extended with the side wall of the hollow cylinder-shaped cutting elements at least in sections. In this way, an optimally-sized outflow diameter is achieved relative to the laminated hole.
This object is also achieved by a cardboard/plastic composite material, a blank made of this and a pouring element which each constitute a part of such a composite pack.
A further teaching of the invention provides that the lengths of the elliptical main axis and of the elliptical minor axis correspond and the laminated hole thus has a circular design.
In further advantageous designs the cutting element for first-time opening of the composite pack is designed to be movable on a screw thread-shaped track or a track with different pitches. Thus, the cutting element can be guided as easily as possible on a thread or also in different variants on a plurality of successive sections. Here, individual sections can guide the cutting element purely axially downwards, purely horizontally, or with any pitches of their screw thread-shaped tracks.
A further development of the invention provides that the first guidance means is designed in a lower region facing the laminated hole with a smaller height than the remaining region. With the present invention in particular, very high forces act on the guidance means, when the cutting element penetrates the pack. In contrast to the known systems in which cutting only takes place in the region of the laminated hole, here the cutting element is always brought into contact with the cardboard carrier layer or even displaces this at least in a certain region. Thus, the further the cutting element has already penetrated the laminated hole, the smaller the remaining regions in which the first and second guidance means further interlock. Only the upper region of the cutting element and correspondingly the lower region of the basic body or its guidance means are in the end position. Therefore, in that upper region, the first guidance means should remain as sturdy as possible, while in the lower region as little friction as possible should be generated when penetrating through the laminated hole and thus along the cardboard carrier layer edge. The lower region of the first guidance means should therefore be designed with the lowest possible height.
According to a further teaching of the invention the lower region of the opened composite pack should be below the laminated hole and thus inside the composite pack. This describes the position of the cutting element in relation to the pack in its end position at the end of the composite pack opening process.
In a further expedient embodiment the first and second guidance means are designed as a combination of individual guide walls and/or individual cams. This allows optional combinations of sections, defining various pitches of the path of the cutting element. As soon as the cutting element is set in motion by the screw cap, the cams can be guided along the guide walls and thus steer the cutting element along the specified path. Various embodiments are conceivable here, such as, for example, guide walls on the cutting element and basic body or also cams on one of the two components combined with guide walls on the respective other.
In a further form of the invention, the first guidance means are configured as a first thread and the second guidance means as a second thread. This solution is above all applied if an individual helical movement is to be performed. A pair of threads also offers the advantage that the two interacting parts are in contact with each other over an extended range and thus offer enhanced resistance to the forces generated during the opening process.
Another teaching of the invention provides that the first thread has an interrupted configuration in the bottom region. Interruptions in the thread allow the resistances that arise during penetration through the laminated hole to be reduced. In particular also, on a multi-start thread these can be configured such that for a specific penetration depth in each case at least a part of each thread is interrupted. Interruptions at various heights in the respective threads can, by way of example, allow a reduction in the average external diameter in the lower region of the cutting element, without an associated excessive variance in this. This allows an easier and even penetration through the laminated hole.
According to a particular version, the heights of the thread sections in the lower region of the cutting element are configured to slope forwards in the direction of rotation. During the helical penetration the part of a respective thread section in the direction of rotation is the first part to come into contact with the surface of the pack. Therefore penetration is made easier if this part is sloped at the lowest possible angle, to allow a constant screwing-in of this thread section.
According to a further teaching of the invention, the second thread is designed as thread sections and/or cams. On the one hand the intention is, if possible, to save material in such consumable items and for this reason alone such a design of the second thread is suitable. On the other, when there is more than one thread, it is often necessary to interrupt the thread to allow the production tooling to be designed as simply and cost-effectively as possible. Finally, this can also be designed as described in EP 1 931 571 B1 by the applicant, to allow a simple and direct assembly of the various individual parts of the pouring element. This simplified assembly works in particular in conjunction with the interruptions in the first thread.
According to a further teaching of the invention, the pouring element and the laminated hole are arranged eccentrically, so that even if the cylindrical external diameter corresponds precisely to the length of the elliptical minor axis, when opening for the first time the cutting element lies at least partially outside the laminated hole. This eccentric arrangement often arises if the pouring elements are applied by a corresponding application device to the packs. Such devices always have a certain tolerance, which in many cases makes it impossible for the corresponding parts to fit together exactly. In the prior art this leads to the cutting path of the cutting element being somewhat closer to the edge of the laminated hole but not outside of this. So, from this aspect, the specific embodiment of the composite pack also allows application devices with high tolerances and thus also associated high speeds.
In a further form of the invention, the cutting element is made from impact-modified polystyrene. Unlike the polypropylene and polyethylene normally used for cutting elements, an impact-modified polystyrene ensures a more stable component.
The invention is described below using a drawing showing just one preferred exemplary embodiment. The drawing shows as follows:
The enlargement of the opening region in
The cardboard/plastic composite material comprises a cardboard carrier layer 15, an aluminium layer 16 and internal and external top layers 17. Particularly easily identifiable is also the stamped edge 5 of the cardboard carrier layer 15, defining the outer border of the laminated hole 3. So, similarly visible is the overlapping of the cutting element 11 with this region.
In
In the section view of
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 117 707.0 | Jul 2018 | DE | national |
| 18020342.4 | Jul 2018 | EP | regional |
This application is the United States national phase of International Application No. PCT/EP2019/069122 filed Jul. 16, 2019, and claims priority to German Patent Application No. 10 2018 117 707.0 filed Jul. 23, 2018 and European Patent Application No. 18020342.4 filed Jul. 23, 2018, the disclosures of which are hereby incorporated by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/069122 | 7/16/2019 | WO | 00 |
