EP0190577A2 - Package for liquids with a spout - Google Patents

Abstract

A package for liquids made of cardboard is described which is liquid-impermeable on its surfaces due to the plastic coating. This pack has side walls, bottom and top wall, which are connected to one another by the fold line (9) and / or other sealing seams. The package is provided with a tearable pouring opening (6) located in the top wall near the edge line (9), which is preferably covered with a tear-off cover strip, and it is provided with a pouring edge lying in one plane with the top wall. To simplify the construction of such a package and to create a pouring edge for a clear pouring jet and edge protection at the edge of the punched pouring opening, the invention provides that a separate plastic strip (10) is sealed in the area of the pouring opening (6), covering it the edge line (9) of the top wall protrudes with an unsealed end to form a pouring edge and that the surface of the plastic strip (10) covering the pouring opening (9) is punched out, exposing the opening (6) and folded over the opening edge (12) and at least from the opening Bottom is sealed.

Description

The invention relates to a package for liquids made of cardboard and the like, which is liquid-impermeable at least on one surface by plastic coating, with side walls, bottom and top wall, which are connected at least partially by folding and / or sealing seams, with one in the top wall close the tear line pouring opening, which is preferably covered with a tearable cover strip, and with a pouring edge lying in one plane with the top wall.

Liquid food packs such as Milk, fruit juices are known. These packs consist of cardboard thinly coated with plastic on both surfaces and form liquid-tight, stable packs that are currently widely used in retail.

In order to enable the contents to be emptied, the packs are equipped with opening devices which are also known per se in a wide variety of shapes and constructions.

A specially known pack for milk has mainly a parallelepiped shape and has, inter alia, the features mentioned at the beginning. In order to facilitate the pouring out of the filling material, the pouring opening has an elongated or oval shape and is oriented in such a way that the major axis of the pouring opening runs at right angles to the edge line of the top wall of the pack. A plastic cover strip is also provided, which is attached to the top wall of the pack in such a way that it covers both the pouring opening and an area surrounding this opening. The cover strip is connected to the top wall in a liquid-tight manner in a zone lying around the pouring opening. An unsealed end of the cover strip can be removed from the Consumers are well handled and pulled up to open them. It is desirable to empty the contents in a uniform and fairly collected jet.

A disadvantage of many packs, however, is that the filling jet tries to follow the outer surface of the pack when it is poured out, so that it splits and partially runs down one of the side walls. This is mainly due to the fact that the edge line created during the formation of the package by folding along a bending edge, over which the product runs, is slightly rounded and not so sharply defined that the product jet on the outer surface of the package can become detached.

To avoid this problem, it has already been proposed to form a sharp tear-off edge or pouring edge for the pouring jet flowing over the top wall with the aid of a part of the top wall which is formed in the plane of the top wall and which is shaped by cutting lines. In order to design this pouring edge, however, exact cuts have to be made in the manufacture of the web, and additional measures have to be taken to stop the leak caused by the cuts. E.g. plastic strips are sealed on the inside in the area of the pouring opening. It would be desirable to have a simpler solution to create a pouring edge with fewer measures and fewer parts on the package.

Another problem has arisen over time in connection with the emptying of the filling material. The pouring opening is usually formed in the already coated cardboard web by punching out. The edge of the pouring opening is therefore a cut line that exposes the uncoated paper edge. When pouring liquids, such as milk or fruit juice, this edge of the pouring opening becomes moist and absorbs liquid. There the top wall in the area around the opening edge not only loses strength, but the appearance also suffers after only partially emptying the filling material, and good conditions can also be created for bacteria, so that health problems could arise. It would therefore be beneficial if this cutting edge could also be covered.

The object of the invention is therefore to provide a Flüssigkeitspakkung of the type mentioned under saving of material, which has a simpler structure and not just a molded edge for a clear AusgieBstrahl but also a _K at the edge of the punched pouring opening Toggle provides tenschutz. Further, a method for producing such a package with improved _A to usgießein- direction and a device for carrying out this method are provided.

With regard to the package, the object is achieved according to the invention in that a separate plastic strip is sealed in the area of the pouring opening, covering it, protruding beyond the edge line of the top wall with an unsealed end to form a pouring edge, and in that the surface of the plastic strip covering the pouring opening is underneath Exposure of the opening punched out and folded around the opening edge and sealed at least from the bottom. According to the invention, both a pouring edge and edge protection for the edge of the pouring opening are thus created by using a single separate plastic strip which is sealed onto the surface of the top wall from the outside. By sealing the plastic strip edge from the inside, an additional cover strip in the area of the inside of the pack is no longer necessary. Both of the above-mentioned problems (pouring edge and paper protection) are solved with one measure.

It is also expedient according to the invention if the Plastic strips are sealed to the top wall along a closed sealing seam surrounding the pouring opening at a distance. According to the invention, the sealing of the plastic strip on the outside of the surface of the upper wall creates a captive pouring edge, which is not accidentally torn off even when the outer cover strip is removed. It has been shown that the mentioned sealing seam as a narrow or narrow sealing zone around the pouring opening is sufficient for an adequate fastening of the plastic strip. However, it may alternatively provide for the sealing of the plastic strip is carried out over the whole area up to the edge of the opening _A usgieß-; and in a special further alternative embodiment it can be advantageous to provide a seal around the edge of the pouring opening, ie in the edge area on the outer surface. The latter two alternatives prevent dirt or other foreign particles from collecting between the top wall and the plastic strip.

It has also been found to be favorable according to the invention if the plastic strip is formed from a thermoplastic film, the thickness of which is five to ten times the plastic coating of the cardboard material, preferably the thermoplastic film for the plastic strip has a thickness of 0.1 to 0.2 mm. In other words, the plastic strip, which covers the pouring opening on the upper wall up to the edge line, is made of a relatively rigid material, so that there is really a sharp pouring edge, with the result that the filling material can be poured out better. Thermoplastics which are particularly suitable for the production of the plastic strip are preferably polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyester. With the individual mixtures, one can also make a desired temperature setting, i.e. set a particularly desired softening temperature.

The method for producing the opening device described above according to the invention characterized in that an opening of overlapping and to beyond the nearest edge line reaching plastic strip is sealed so to the area of the punched out of the top wall of the pouring opening such that its end is in the range of _R andlinie remains sealing free, that the surface above the pouring opening is deep-drawn to a level below the top wall and a hole is punched out of the plastic strip at a distance from the opening edge, the closed edge of this hole is folded over in the plastic strip and sealed from the inside of the package next to the edge of the pouring opening. The plastic strip is therefore softened after being placed on the area of the pouring opening or is deep-drawn in its still soft state. This deep-drawing takes place in the pouring opening down to the inside of the pack down to a level below the top wall, so that the deep-drawn, approximately parallel surface of the deep-drawn plastic strip lies at a distance below the top wall inside the pack. This advantageously results in ring surfaces that protrude downward into the interior of the pack approximately perpendicular to the surface of the top wall and that are conical from the inside of the pack before or after the hole is punched out of the plastic strip itself (not to be confused with the pouring opening in the box) by suitable tools expanded and sealed from the inside of the package to the inner surface of the top wall. In other words, in addition to the edge of the pouring opening, a sealing seam is created in a circular or oval shape around the pouring opening, which also forms a handle or fastening area for the plastic strip from the inside of the pack. This not only significantly improves the captivity of the plastic strip, but also provides edge protection for the edge of the pouring opening, because liquid can no longer be absorbed by this opening edge and penetrate into it.

As already stated above, the hole can be made from the plastic strip before or after being folded over and sealed onto the inside of the package.

Deep drawing can be carried out in a manner known per se by means of a vacuum or mandrel.

If you want to use the method advantageously in a package that is made continuously or intermittently from a tubular web of material, then it is expedient if, according to the invention, the plastic strip is applied during the creasing, punching and cutting of the cardboard web in that it is applied by a The supply roll is pulled off, pushed onto the area of the pouring opening, cut and sealed. During the movement of the cardboard web already coated on both sides with plastic in the packaging machine, the corresponding cuts and seals can be carried out, the creasing, punching and cutting of the cardboard web possibly being carried out simultaneously or in between.

It is particularly advantageous according to the invention if the sealing is carried out by high-frequency welding. Another alternative is hot air or electric heating of panels.

When applying for a further embodiment of the invention the plastic strips in a heated to such a temperature condition on the top wall of the package, that the plastic strip may be sealed and deep-drawn, then advantageously a separate supply of _W less advan- me superfluous because the plastic strip already in is suitably tempered before sealing and deep drawing.

While the position of the plastic strip on the surface of the top of the pack towards the middle more or more is less critical, the size of the Kunststoffstrei- _f ens towards the edge line, via which the filling material is poured in jet form, advantageously then properly dimensioned in a preferred manner, when vertically in plan view of those on the package upper wall, the outer edge of the plastic strip about in the line including located fold line, which was called the front edge line of the top wall. This results in the advantage that the cover strip, which is placed on the outside over the plastic strip and folded over the edge line on the front side edge and fixed there, does not damage or kink the pouring edge. Rather, the relatively stiff plastic strip remains undeformed in the plane of the top wall even during transportation before opening. In normal 1-liter milk packaging in cuboid shape, a protrusion of this front edge of the plastic strip above the edge line between the top wall and side wall of the package by 0.5 to 2 mm, and preferably 1 mm, has been found to be particularly suitable.

The device for carrying out the method described above is characterized according to the invention in that the counter-jaw counteracting the pressure mandrel has a punching device. If you create a combination of counter jaws and punching device or pressure mandrel and punching device, you can use simplified tools and thus achieve a faster work cycle. For example, a machine equipped with the device according to the invention is capable of producing 6000 _p accumulations per hour in the desired manner.

It is further preferred if the device according to the invention has a counter jaw which is designed as a contact heating plate. This measure complements the other heating options for the plastic film already mentioned above, namely hot air or high-frequency welding.

• Figur 1 perspektivisch eine Flüssigkeitspackung mit dem erfindungsgemäßen Streifen und Merkmalen,
• Figur 2 schematisch, perspektivisch und abgebrochen eine Querschnittsansicht durch die Ausgießöffnung, wobei der mit Kunststoff beidseitig beschichtete Karton zunächst lediglich mit einer Ausgießöffnung versehen ist,
• Figur 3 die Ansicht ähnlich der Figur 2, wobei jedoch der Kunststoffstreifen auf den Bereich der Ausgießöffnung aufgelegt und dort aufgesiegelt ist,
• Figur 4 ebenfalls schematisch die Draufsicht auf die Oberwand der Packung mit aufgesiegeltem Kunststoffstreifen (ohne den äußeren Abdeckstreifen),
• Figur 5 schematisch eine Querschnittsansicht der mit der Ausgießöffnung versehenen Flüssigkeitspackung mit aufgesiegeltem Kunststoffstreifen gemäß einem ersten Verfahrensschritt nach dem Tiefziehen,
• Figur 6 eine gleiche Ansicht wie in Figur 5, jedoch unter Darstellung des der Figur 5 nächstfolgenden Verfahrensschrittes für das Aufsiegeln der Flansche auf die Innenseite der Packung,
• Figur 7 eine ähnliche Ansicht wie Figur 6, wobei jedoch bei einem nächsten Verfahrensschritt das Ausstanzen des Loches im Kunststoffstreifen gezeigt ist,
• Figur 8 eine andere Ausführungsform des _Druckdornes, in ähnlicher Darstellung wie gemäß Figuren 5 bis 7, wobei jedoch die Form der Aufsiegelung von der Innenseite der Packung her anders als bei der Ausführungsform nach den Figuren 6 und 7 erfolgt, und
• Figur 9 die ähnliche schematische und abgebrochene Schnittansicht wie in Figur 8 unter Darstellung des fertig aufgebrachten Kunststoffstreifens, wiederum ohne den äußeren Abdeckstreifen.

Further advantages, features and possible applications of the present invention will become apparent from the following _B e-scription in conjunction with the drawings. Show it:

• FIG. 1 is a perspective view of a liquid pack with the strip and features according to the invention,
• FIG. 2 shows a schematic, perspective and broken-away cross-sectional view through the pouring opening, the carton coated on both sides with plastic initially being provided only with a pouring opening,
• 3 shows the view similar to FIG. 2, but with the plastic strip placed on the area of the pouring opening and sealed there,
• FIG. 4 also schematically shows the top view of the top wall of the package with the sealed-on plastic strip (without the outer cover strip),
• FIG. 5 schematically shows a cross-sectional view of the liquid pack provided with the pouring opening with a sealed-on plastic strip according to a first method step after deep drawing,
• FIG. 6 shows the same view as in FIG. 5, but showing the process step following FIG. 5 for sealing the flanges onto the inside of the pack,
• FIG. 7 shows a view similar to FIG. 6, but showing the punching out of the hole in the plastic strip in a next method step,
• Figure 8 ruck dornes another embodiment of the _D, except that the shape of the Aufsiegelung otherwise carried out in a similar representation as in figures 5 to 7, from the inside of the package forth as in the embodiment of Figures 6 and 7, and
• Figure 9 shows the similar schematic and broken sectional view as in Figure 8 showing the finished applied plastic strip, again without the outer cover strip.

In Figure 1, the liquid pack is first shown in perspective from the outside. _M an recognizes the top wall 1, the narrow side wall 2 pointing to the left towards the viewer and the wide side wall 3 pointing towards the right to the front of an approximately cuboid-shaped liquid pack. This pack is formed from a tube, the sealing seam 4 serving to form the tube.

At the opposite narrow ends of the top wall 1, a triangular flap 5 is formed over an edge line 9, which according to the illustration in FIG. 1 is folded down onto the adjacent side wall 2 and attached there.

In the top wall 1 is the pouring opening 6, which is covered by an outer cover strip 7 in a manner known per se (pull tab).

A separate plastic strip 10 is sealed in the area of the pouring opening 6 via the narrow sealing seam 13 shown in FIGS. 3 and 4 on the outside and the annular sealing surface 20 on the inside. The plastic strip 10 covers the pouring opening 6, as can be seen particularly clearly from FIG. 3.

The plastic strip 10 projects forward by a very small amount (0.5 to 2 mm) beyond the edge line 9 of the top wall 1. Directly next to the pouring edge 8 thus formed, the end 11 of the plastic strip 10 is not sealed to the top wall 4.

Incidentally, as an aid to understanding, it should be said that the edge line 9 in the sectional representations according to FIGS. 2, 3 and 5 to 9 is excessively round. The representation of FIG. 7 comes closest to the actual bending shape of the outer edge line 9. In any case, it is not about sharply defined edges as shown in perspective in the schematic FIG. 1.

The design of the entire opening mechanism with the plastic strip 10 can best be seen in the description of the production method according to FIGS. 2 to 7 for the first embodiment and FIGS. 8 and 9 for the second embodiment.

FIG. 2 shows the perspective, schematic sectional view of the packaging corner on the left according to FIG. 1, the triangular tab 5 and also the cover strip 7 not being shown. First, only the pouring opening 6 is punched into the top wall 1, and the free opening edge 12 is obtained without any coating, which is a cutting line. Without protection of this edge or edge 12, liquid could penetrate into the area of the annular surface 12 and cause the softening and impurities described.

As a measure for creating the pouring edge 8 and also for the edge protection or for covering the opening edge 12, the plastic strip 10 is provided, which, according to FIG. 3, is placed on the area of the pouring opening 6. It clearly covers the pouring opening 6 and extends at least to the closest edge line 9 (FIG. 1 left); but preferably projects beyond this by a small piece of approximately 1 mm. In the last area, i.e. The end 11 of the plastic strip 10 is seal-free via a 0.5 to 3 mm wide strip parallel to the pouring edge 8. In the embodiment of FIG. 3, the plastic strip 10 is fastened on the outside only via the sealing seam 13 to the top wall 1, so that more than the end 11 of the plastic strip 10 is seal-free. If, however, a larger sealing surface than only the seam 13 according to FIG. 3 is provided, as mentioned at the beginning, the end 11 in the region of the edge line 9 of the plastic strip 10 should always remain sealed with the top wall 1.

FIG. 4 shows the top view of the plastic strip 10 thus placed with the pouring edge 8.

While the pouring opening 6 with the opening edge 12 already exists in the box, the plastic strip 10 is initially still without a hole. 5, the material of the plastic strip 10 lying above the pouring opening 6 is deep-drawn into the opening 6 with the pressure mandrel 17 and the counter jaw 16. _Since - by arise annular surfaces 21, which can later be used for sealing from the inside.

According to FIG. 6, the next step is shown, in which the entire deep-drawn bottom part is pressed upwards with the aid of the pressure mandrel 17. The final state achieved in this way can be seen in FIG. 6, the annular walls 21 now forming a type of flange (FIGS. 6, 7 and 9).

After reaching the state of Figure 6 of the deep-drawn part of the plastic strip 10 will now by means of the device _S dance 18 to form a hole 14 punched at a distance from the opening edge 12th The stamped-out circle or oval of the plastic strip is shown schematically in FIG. 7 and designated by 22. If one thinks away the counter jaws 16 with the punching device 18 and the disk 22 in FIG. 7, then the illustration in FIG. 7 - even if without the outer cover strip 7 - is the final state of the outside and inside (via the annular surface 20 ) sealed plastic strip 10.

In the other embodiment, the situation is similar according to FIGS. 2 to 5, only the riveted cross-section of the deep-drawn part does not take place to form the double flange, as shown in FIGS. 6 and 7. Again the major part of the deep-drawn material is punched out, so that the hole 14 according to FIG. 8 results. Before the side flanges of the remaining deep-drawn parts are turned against the inside, the pressure mandrel 17 is in the position shown in FIG. It is moved up and down according to arrow 23 the flanges 24 on the inside. These are then sealed again via the areas 20. The final state is then reached in FIG. 9, the edge 12 of the pouring opening 6 being protected by the edge of the hole in the plastic strip 10.

Claims (9)

1. Pack for liquids made of cardboard or the like, which is liquid-impermeable at least on one surface by plastic coating, with side walls (1-3), bottom and top wall (1), which are at least partially folded (9) and / or sealed ( 4) are connected to one another, with a tearable pouring opening (6) located in the top wall (1) near the edge line (9), which is preferably covered with a tear-off cover strip (7), and with one in one plane with the top wall ( 1) lying pouring edge (8), characterized in that a separate plastic strip (10) in the area of the pouring opening (6), covering this, is sealed over the edge line (9) of the top wall (1) with an unsealed end (11) underneath Forming a pouring edge (8) protrudes and that the surface of the plastic strip (10) covering the pouring opening (6) is punched out by exposing the opening (6) and folded over the opening edge (12) and at least from the lower part ite is sealed. 2. Pack according to claim 1, characterized in that the plastic strip (10) along a closed, the pouring opening (6) at a distance surrounding sealing seam (13) on the top wall (1) is sealed. 3. Pack according to claim 1 or 2, characterized in that the plastic strip (10) is formed from a thermoplastic film whose thickness is five to ten times the plastic coating of the cardboard material, preferably has a thickness of 0.1 to 0.2 mm . 4. Method of making an opening device A pack according to one of claims 1 to 3, characterized in that on the area of the pouring opening (6) punched out of the top wall (1) there is a plastic strip (10) covering the opening (6) and reaching beyond the closest edge line (9). is sealed so that its end (11) remains seal-free in the area of the edge line (9), that the surface above the pouring opening (6) is deep-drawn to a level below the top wall (1) and at a distance from the opening edge (12) Hole (14) is punched out of the plastic strip (10), the closed edge (15, 21) of this hole (14) is folded over in the plastic strip (10) and sealed from the inside of the package next to the edge (12) of the pouring opening (6) (20) will. 5. The method according to claim 4, characterized in that the plastic strip (10) is applied during the creasing, punching and cutting of the cardboard web in that it is pulled from a supply roll, pushed onto the area of the pouring opening (6), cut and sealed . 6. The method according to claim 4 or 5, characterized in that the sealing is carried out by high-frequency welding. 7. The method according to any one of claims 4 to 6, characterized in that the plastic strip (10) is applied to the upper wall (1) of the package in such a heated state that the plastic strip (10) can be sealed and deep-drawn. 8. Device for performing the method according to one of claims 4 to 7, characterized in that the counter-jaw (16) counteracting the mandrel (16) has a punching device (18). 9. The device according to claim 8, characterized in that the counter jaws (16) is designed as a contact heating plate.

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