EP0044591B1

EP0044591B1 - Collective package of packing containers and a method of manufacture of the same

Info

Publication number: EP0044591B1
Application number: EP19810200782
Authority: EP
Inventors: Lennart Ignell Rolf
Original assignee: Tetra Laval Holdings and Finance SA; Tetra Pak Developpement SA
Current assignee: Tetra Laval Holdings and Finance SA
Priority date: 1980-07-21
Filing date: 1981-07-08
Publication date: 1984-09-12
Also published as: SE8005275L; JPS5755866A; EP0044591A1; DE3166023D1

Description

The present invention relates to a collective package comprising a number of packing containers which are mutually connected by means of two separate connecting elements, namely a first sheet of material which is connected to a closing arrangement on each packing container and a second sheet of material which is connected to each one of the bottom ends of the packing containers, whereby the second sheet of material is constituted of a number of coherent profiled foot portions for the packing containers.
A number of different beverages are packed currently in packing containers of the non-returnable type. For beer, carbonated refreshing beverages and the like, usually packages in the form of jars or bottles of sheet metal or plastics are used, which have a size varying between 19 and 45 cl. These packing containers are packed and sold connected to one another to form so-called multi-packs containing 4, 6, 8 or 10 packing containers, which in an appropriate manner are detachably connected to each other. The method of joining together a certain number of individual packing containers to a larger collective package or so-called multi-pack not only facilitates handling and distribution, but can also have a sale-stimulating effect, so that the method becomes more and more widespread. To allow the above-mentioned advantages to be obtained in full, however, it is a precondition that an optimum method and arrangement for the fixing of the individual packing containers in the collective package is available, that is to say that a stable collective package which is easy to handle is obtained, at low cost, without involving any unnecessary difficulties when the individual packing containers are to be detached, or on disposal of the waste material.
A method of holding together a greater number of packing containers in a collective package used frequently up to now consists in placing the individual packing containers on a piece of cardboard with or without borders, and wrapping up the cardboard sheet as well as the packing containers in shrink film. This procedure permits the forming of relatively large collective packages, since it gives a package with very good stability and durability. However, the method is complicated and expensive. It produces moreover large quantities of waste which has to be disposed of when the collective package has been opened up.
Another known method for forming collective packages consists in arranging a number of individual packing containers in a collective group and applying a strip of paper provided with holes or recesses, a so-called cardboard shroud, around the group. This method produces a stable collective package, but it is expensive and generates much waste material.
Another known method (US-A-3.784.002) makes use of a strip with holes or recesses into which the individual packing containers are introduced subject to a certain expansion of the strip material. This method is relatively inexpensive but produces unstable collective packages and cannot be used therefore in the case of collective packages with a greater number of individual packing containers. Especially in large collective packages it is necessary, in order to achieve the desired stability, to connect the individual packing containers to one another at not less than two points situated at a distance from one another, e.g. at the top and bottom respectively of the packing containers. This is shown in FR-A-2 302 250, where two separate connecting elements are used. Each connecting element has profiled recesses for the tops and the bottoms, respectively, of the bottles. Up to now it has not been possible, however, to produce this kind of collective packages at acceptable costs.
In FR-A-2.389.541 a further known type of a collective package is shown, which package includes a connecting element that functions as a liquid-tight lid for a number of individual containers also after the separation from the multi-pack. However, neither this nor any other known construction uses a technique where individual container bodies are completed into finished packing containers with foot-parts and air-tight closures only when they are placed in the multi-pack, which is the main idea behind this invention.
It is an object of the present invention to provide a collective package of a desired number of individual packing containers, which collective package, at a low cost, fulfils the two main requirements, namely small material consumption and good stability.
It is a further object of the present invention to provide a collective package which is simple to manufacture, simple to use and which makes it possible to remove each individual packing container without the cohesion between the remaining packing containers included in the collective package being lost.
The abovementioned objects are achieved in accordance with the invention substantially in that the parts forming the collective package are integrated in the packing containers and are given double functions, e.g. beside the connecting function, also a sealing, stiffening or stabilizing function for each individual packing container.
More particularly, the abovementioned objects have been achieved in accordance with the invention in that a collective package comprising a number of packing containers which are mutually connected by means of two separate connecting elements, namely a first sheet of material which is connected to a closing arrangement on each packing container and a second sheet of material which is connected to each one of the bottom ends of the packing containers, whereby the second sheet of material is constituted of a number of coherent profiled foot portions for the packing containers have been given the characteristic that the first sheet of material comprises a layer of a material with high gas-tightness, which is firmly sealed to the top surface of the closing arrangements and that both the first and the second sheet of material have breaking directions between the individual packing containers. Owing to the connecting elements of the collective package being firmly connected to each one of the packing containers and constituting an active part of the same, the total costs of the collective package with the packing containers included therein can be minimized.
The present invention also relates to a method for the manufacture of a collective package of packing containers. More particularly, a method for the manufacture of a collective package wherein a number of filled and closed container bodies are combined in a predetermined formation and are connected by means of a first and a second sheet of material has been given the characteristic that the first sheet comprising a layer of a material with high gas-tightness is applied over and sealed to the top surface of the closing arrangements and that the second sheet of material comprises profiled foot portions which by means of mechanical engagement are connected to the bottom ends of the container bodies.
Preferred embodiments of the collective package as well as of the method in accordance with the invention have been given the characteristics which are evident from the respective subsidiary claims.
The manufacturing method in accordance with the invention makes it possible to produce containers with a highly pressure-resistive and simple form at an extremely high speed. The necessary air-tight parts (al-folie) of the caps and the foot-parts must not be produced or mounted separately as they are parts of or in fact together constitute the connecting parts of the multi-pack. Thus, both material, labour and work can be saved which means that the cost for each package can be kept extremely low in comparison with conventional packages for beer or carbonated beverages.
A preferred embodiment of the collective package in accordance with the invention will now be described in more detail with special reference to the enclosed schematic drawings which only show details required for an understanding of the invention.

Figure 1 shows in perspective and partly in section a collective package in accordance with the invention.
Figure 2 shows a number of connected foot portions of packing containers in accordance with the invention.
Figure 3 shows an alternative embodiment of the collective package in accordance with the invention.

The preferred embodiment of a collective package in accordance with the invention shown in Figure 1 comprises six individual packing containers 1, which by means of two sheets of material 2, 3 serving as the upper (first) and lower (second) connecting element respectively are connected to each other in a symmetrical formation. The upper sheet of material 2 as well as the lower sheet of material 3 are firmly connected to each one of the packing containers and constitute moreover an active part of the same, that is to say the two sheets of material do not only serve as connecting elements for the holding together of the individual packing containers to a collective package, but they also constitute an integrated part with a special function for each individual packing container, e.g. a sealing or stabilizing function, which will be described in more detail in the following.
Each individual packing container included in the collective package is of the non-returnable type and comprises a container body 4, manufactured from a suitable plastic material, which is substantially cylindrical with semispherical ends. The container body 4 has at its upper end an emptying opening, not shown in the drawing, in the form of a short neck provided with flange onto which a closing arrangement 5 is applied. At the opposite end of the container body 4 there is a foot portion 3' which is attached in any appropriate manner to the lower end of the container body, e.g. by mechanical engagement (snap effect) with a bulge, not shown on the drawing, situated at the lower end of the container body.
As is evident particularly from Figure 2, each foot portion 3' is manufactured in one piece with a number of further foot portions which together form the one connecting element of the finished collective package, more particularly the lower profiled sheet of material 3. The foot portions 3' are manufactured from a formable, preferably thermoplastic, sheet material which through thermoforming and punching is remoulded to foot portions of the desired profile. Each foot portion comprises an outer substantially conical support 8 and a dished fixing part 7 situated concentrically inside the same, whose profile section corresponds substantially to the profile section of the lower end of the container body 4. The application of the foot portion 3' to the container body 4 takes place by mechanical engagement with a bulge located at the lower end of the container body 4, whose diameter somewhat exceeds the diameters of the centre holes 8 of the foot portion 3'. Thanks to this a predetermined number of container bodies 4 in a defined formation can be introduced at the same time into and be attached to a lower sheet of material comprising a corresponding number of foot portions 3'. Between each individual foot portion 3' in the lower sheet of material 3 there is a narrow and relatively weak connection 9, which is breakable by itself when the individual packing containers are to be separated from the collective package. If desired, the connection 9 may also be provided with further weakening arrangements serving as breaking directions, e.g. a perforated line. The outer conical supports 6 of the foot portions are very suitable for the application of trade marks, information on the goods or other markings which may be applied in relief onto the foot portion simultaneously with the forming of the same.
The packing containers 1 included in the collective package are held together at their upper end by means of the upper connecting element, which is in the form of a sheet of material 2 attached to the closing arrangements 5 of each of the packing containers 1 included in the collective package. More particualrly, parts of the sheet of material 2 rest against the upper surface of each closing arrangement. Parts 2' of the sheet of material corresponding to the form and size of the said surfaces are delimited from the intermediate portions of the sheet of material by means of breaking direction lines 10 which extend substantially in a circle around the upper, peripheral edge of each closing arrangement 5. In this manner the sheet of material 2 can serve as a connecting element for the packing containers included in the collective package, whilst at the same time each one of them can be readily removed from the collective package, in that the corresponding portion 2' of the sheet of material is removed by breaking the breaking direction 10.
As mentioned earlier, the sheet of material 2 also constitutes an active part of the individual packing container. More particularly, the portions 2' of the sheet of material delimited by the breaking directions 10 function as gas-tight layers in the individual closing arrangements 5. The closing arrangements 5 are made of thermoplastic material which in a simple manner can be shaped to the desired form and which has excellent properties when a liquid-tight closing of a packing container is required. However, such thermoplastic material cannot be endowed with the gas-tight characteristics necessary for the packaging of e.g. carbonated refreshing beverages or beer, so that it has been customary up to now to provide each closing arrangement with an internal gas-tight layer of aluminium foil or gas-tight plastic varnish. In accordance with the invention, this gas-proofing function is transferred instead to the sheet of material 2 which is in the form of a laminated material comprising layers of thermoplastics and layers of high gas-tightness, e.g. aluminium foil. After being sealed to the top surface of each closing arrangement 5, the delimiting portions 2' of the sheet of material will serve as an external gas-tight layer on each individual closing arrangement. By giving the sheet of material 2 the form of a laminate comprising layers of thermoplastics and aluminium foil, a further advantage is obtained, namely that the sheet of material, in a simple manner, can be induction-welded to the top of the closing arrangement 5.
In the manufacture of a collective package in accordance with the invention use is being made of the special shape of packing containers which has been described above. After the manufacture of the container bodies 4 and filling of the same with the appropriate contents and application of the closing arrangements 5, a predetermined number of container bodies is combined to a desired formation, e.g. that shown in Figure 1, which comprises six container bodies arranged symmetrically two by two in three rows. After the container bodies have been combined so that their cylindrical side parts rest against each other in substantially linear contact surfaces, they are combined with a lower sheet of material 3 consisting of a corresponding number of foot portions 3' which are arranged in the same formation. The lower ends of the container bodies 4 are then introduced at the same time into corresponding fixed parts 7 in the foot portions 3' and are connected by way of engagement between the centre hole 8 and the bottom end of the respective container body. At the same time the prefabricated sheet of material 2 provided with breaking directions 10 and lifting lugs 11 is applied in the correct position over the group of packing containers so that each portion 2' of the sheet of material, delimited by a breaking direction 10, covers fully the upper surface of the closing arrangements 5, whereupon the sheet of material is sealed to the said top surface or its peripheral edge. This heat-sealing, as mentioned earlier, can be done appropriately by induction-welding, if the material sheet comprises layers of aluminium foil and thermoplastic material. The collective package is then ready for further transport, to be sold and consumed. Packing containers in accordance with the invention may also be combined to a collective package of the form as shown in Figure 3. This formation permits, moreover, a reduced material consumption in the manufacture of the upper sheet of material and a more stable unit, since 9 linear contact surfaces between the bottles are obtained instead of 7 contact surfaces in the formation according to Figure 2.
The stability of the collective package is increased substantially by the fact that the packing containers included in the collective package are fixed by means of the connecting elements at such a mutual distance from one another that they rest against each other in the elongated zone between the two connecting elements. In the case of packing containers of the preferred type with a substantially cylindrical middle portion, a dimensioning of the connecting elements in relation to the size of the packing containers is chosen for the above- mentioned reason, which is such that the distance between the centre lines of the packing containers included in the collective package is equal to or slightly smaller than the largest diameter of the packing containers. In this manner a firm contact is provided between the containers, and the collective package will be particularly stable and easy to handle. Since the packing containers are normaly filled with contents which are of a low temperature (e.g. +3°C for beer) and as they are then directly combined into the desired formation and the two connecting elements are applied, the contact pressure between packing containers will to a certain extent increase at the rate of the rising of the temperature of the contents to the ambient temperature. The expansion of the packing containers caused thereby will be fairly small, of course, but the cumulative effect nevertheless will be significant for the contact between the packing containers and effectively contribute to the collective package on handling behaving as a "compact" and steady unit.
It is quite possible, of course, to provide the upper layer of material 2 just like the lower layer of material 3 with decoration, e.g. trade marks and informative text, which in the large and unbroken surface will be clearly visible and have high publicity value when the collective packages are put up for sale in the shops.
As is evident from what has been said above, a collective package which fulfils high demands regarding stability and economy is provided in accordance with the invention by optimization of individual packing containers. This is due first and foremost to the parts included in the collective packages for the holding together of the individual packing containers being made use of both as connecting elements and as active elements with special significance for each individual packing container, e.g. as a gas-proofing part in each individual closing arrangement or as a stabilizing foot for the individual packing containers. As a result the otherwise necessary costs for corresponding parts and their installation are eliminated, which makes the total economy of the collective package very favourable.

Claims

1. A collective package comprising a number of packing containers (1) which are mutually connected by means of two separate connecting elements, namely a first sheet of material (2) which is connected to a closing arrangement on each packing container (1) and a second sheet of material (3) which is connected to each one of the bottom ends of the packing containers, whereby the second sheet of material (3) is constituted of a number of coherent profiled foot portions (3') for the packing containers (1), characterized in that the first sheet of material (2) comprises a layer of a material with high gas-tightness, which is firmly sealed to the top surface of the closing arrangements (5) and that both the first and the second sheet of material (2, 3) have breaking directions (9, 10) between the individual packing containers (1).

2. A collective package in accordance with claim 1, characterized in that the packing containers (1) are held in firm contact by the connecting sheets.

3. A method for the manufacture of a collective package in accordance with any one of the preceding claims, wherein a number of filled and closed container bodies (4) are combined in a predetermined formation and are connected by means of a first and a second sheet of material (2, 3), characterized in that the first sheet (2) comprising a layer of a material with high gas-tightness is applied over and sealed to the top surface of the closing arrangements (5), and that the second sheet of material (3) comprises profiled foot portions (3') which by means of mechanical engagement are connected to the bottom ends of the container bodies.

4. A method in accordance with claim 3, characterized in that the first sheet of material (2) is heat-sealed to the upper peripheral surface of the closing arrangements (5).

5. A method in accordance with claim 4, characterized in that the first sheet of material (2) is induction-welded to the top side of the closing arrangements (5).