EP0223094B1 - Package for liquids made of plastic-coated material - Google Patents

Abstract

A pack for fluid media, comprising a tube (1) forming side walls (2, 3) as well as a cover (5) and a base, which cover and base are fitted to end edges (4) of the tube (1) is provided. At least the side walls (2, 3) and the base are made of plastics-coated carrier material incorporating paper, cardboard or the like, and the base is formed by folded-over wall panels which are formed integrally with the tube (1), providing two mutually oppositely disposed double-walled triangular panels which are in communication with the interior of the pack. The cover (5) is also formed by folded-over wall panels (6) which are formed integrally with the tube (1) and edges (7) of the wall panels (6) are fluid-tightly connected together by injected bridges (8) of plastics material.

Description

The invention relates to a packaging for flow agent, consisting of a tube forming the side walls and lid and bottom, which are attached to the end edges of the tube, at least the side walls and the bottom of plastic-coated carrier material made of paper, cardboard or the like and The bottom and the lid are formed by folded-over wall panels which are formed in one piece with the tube, two opposite, double-walled triangular panels being formed on the bottom and communicating with the interior of the packaging.

A packaging of the type mentioned above is known from EP-A-74.340. The flat or even base serves for good stability, while the lid is designed as a gable with inclined surfaces protruding over the upper end folding edges of the tube.

Opening such gable packaging often presents difficulties for the end user. Nevertheless, this known package is often used for liquid foods, for example juices and milk, and even the aseptic configuration of the known package is possible because all the walls of the package consist of paper, which may be gas-impermeable Metal foil can be coated.

But not only for the end user, but also for the manufacturer who has to create the appropriate filling machines, the tension between the tightness in the lid area on the one hand and the easy opening possibility is a problem.

From FR-A-2,088,539 a completely open and cup-shaped pack of various designs is known, in which side walls or even side walls with a base are made from prefabricated blanks by injection molding of ribs and sealing seams. These seams and in particular the longitudinal sealing seams on the tube are carefully made smooth on the outside so that the finished cups can be stacked or inserted into one another. After filling, separate lids must then be placed tightly. To open the known package, it is assumed that the lid is removed. Adjacent edges of opposing side walls or bottom flaps are provided with injected plastic ribs for fastening to one another.

Such a cup-shaped package is difficult to make gas-tight and therefore can hardly be used for the packaging and transportation of sterile goods. In addition, the person skilled in the art knows that the creation of a one-sided open pack in cup shape is relatively simple by folding, sealing or by the injection molding process, especially since the interior of the cup pack can be filled with a mandrel as the inner mold half. On the other hand, attaching a lid is much more difficult, especially if the package is to be filled with a liquid up to the top.

For this reason, packaging with a gable closure has been used to a large extent for the packaging and transport of liquid dishes, because there it is possible to close the tabs that protrude above the liquid level. However, attaching and welding a separate flat lid onto a filled cup pack is always problematic.

The invention has for its object to further develop a plasticizer of the type mentioned in such a way that an easy to manufacture closure of the tube, which can also be produced continuously, is achieved with the least possible use of material, good fluid tightness and even good gas tightness. The handling of the package and in particular its closure is easy for the end user, and in addition it should also be possible to easily open or even reclose the package.

This object is achieved in that the edges of the plastic-coated wall panels made of paper in the surface of the lid are closely adjacent while leaving narrow gaps and are liquid-tightly connected to one another by plastic bridges injected into these gaps, that an opening device is injected into the lid surface and that the tube has a double-T-shaped butt weld in cross section. In contrast to the known package described at the outset, the lid, which is no longer designed in the shape of a gable, is shaped in a special way by wall panels which are still made in one piece with the tube, but which are designed in such a way that they have edges which are only narrow Gap from the edge of the adjacent wall field come to lie closely next to it, so that plastic bridges can be injected into the gap between the field edges. The amount of plastic required to create such a lid is small. The The main part of the pack is still made of coated paper, even the main part of the lid. It is only necessary to bridge the gap between the individual wall panels at the end edge of the tube next to the cover. Even if these plastic bridges would have to be made thicker, such as, for example, the ribs in the plastic cup pack, the total amount of material used for the plasticizer pack according to the invention remains relatively small. The plastic material for the bridges mentioned should be easy to spray, so that preferably polyethylene, polystyrene or propylene is used. Because of the thicker wall thicknesses for the plastic bridges, the gas tightness of the new lid is also better than that of the lid, which only consists of plastic over the entire lid surface. The new packaging according to the invention offers the advantages of a plastic cover, and yet the advantages of the lower material consumption and the better gas tightness of a paper packaging are achieved. The new pack is also provided with a pouring device that is easy to open and possibly even reclosable, because the opening device is injected directly into the lid surface.

The advantageous production of the pack according to the invention is also favorable. The tube and base can be easily formed and sealed using conventional methods. In addition, no special punchings, folding lines or the like are required for the lid, which go beyond the usual punching and folding technology. Critical points for the welding and the tightness are not present. The bridges can be injected using the proven spraying methods for injecting a lid onto a paper tube, including the formation of the longitudinal sealing seam.

By using a butt weld as a double T-shaped seam in cross-section, you can produce without paper waste. The paper consumption can be optimized because the paper consumption can be optimized because almost only the amount of paper is used that covers the area to be closed by the lid. On the side of the blank which later forms the upper edge of the tube, the wall panels formed in one piece with the tube are provided in such a way that, after the tube is formed, these wall panels provide the desired cover surface almost 100%. It is useful if two blanks are transported opposite to each other so that the wall sections of the one blank, which are formed in one piece with the tube, lie directly adjacent to those of the other blank. In other words, by means of a cut or a zigzag cut line between the two cuts, the wall areas in question can be created to form the lid of the pack. A cut (zigzag line) thus creates two groups of opposing wall panels. This means "almost" no paper waste. Furthermore, since the effort of the plastic for the lid is low, the device according to the invention can be created with the least possible material.

The cut line for delimiting the wall panels made of paper results in cut lines at their edges, which have penetrated the plastic coating and expose the carrier material, the paper, to the outside. If these wall panels are folded over to form the surface of the cover, narrow gaps result, into which liquid should not penetrate, because otherwise they would penetrate into the open-porous carrier material and could lead to destruction. According to the invention, however, the plastic bridges are now injected into this gap. This is Any endangered cutting line covered by plastic, the individual wall panels are firmly and sealingly connected to each other, and this results in a stable overall surface as a cover by means of a spraying process, in which a mandrel inside and a counter mandrel outside ensure the exact shape. When creating the preferably zigzag line between the two blanks (in each case at the end of the tube on the cover side), more or less wide gaps can be provided between the folded-over paper wall panels, so that the plastic bridges that are injected into this column after falling over are more or less can be made thick. In general, the gaps between the wall panels folded down into the cover surface are narrow and almost touch, so that the amount of plastic for the bridges to be injected remains small.

It is also advantageous if the cover is formed from at least four triangular wall panels. If there are exactly four triangular wall sections on the lid-side tube edge, you can conveniently form a square pack with a cross-section that is particularly easy to grip over the diagonal and is particularly rigid. If several wall panels are provided, the outer contour of the cover can be made round. However, this is an approximate solution, because the folded edge of the wall panels remains more or less straight, so that the surface of the cover is generally formed by a polygon. In exceptional cases, however, a rounded folded edge could also be provided in order to complete the outside of the lid surface with a round edge, with a small increase depending on their size at the points of contact of two adjacent wall panels or the points of contact lying on small tips. With a sufficient number of wall fields, this design can result in an appealing, special design.

In general, however, it is expedient if, according to the invention, the cover is flat or conical. In the case of a square or polygonal lid, the corresponding shaping of the wall panels enables folding into a plane which is essentially perpendicular to the tube axis. In a different configuration of the wall panels, for example if their upper tips, which meet after folding in the center of the cover surface, are provided to be further away from the folded edge, or in other words steep or high pointed triangular panels are formed, a conical surface results.

It can be particularly advantageous if the opening device is attached in the middle of the cover. It is then molded onto the inner tips of the wall panels mentioned. For example, pieces can be cut off at the upper or middle tips of the wall panels to form a recess or an opening into which the said opening device is injected and through which the filling material can be poured out. But even if the opening device is located anywhere in the cover surface, which is preferably also provided closer to the edge, an opening can be formed according to the invention in that the opening device is injected into a recess punched into at least one paper wall panel. A hole of any geometry can be punched or cut out on the outside or inside in the paper wall field, so that there is the aforementioned recess, which is molded on the one hand to form the opening device and forms the opening through which the filling material can be poured out. Thanks to the advantageous spray technology, different designs of opening devices can be used: those with reclosability, those with molded pouring edge, etc.

It is also expedient according to the invention if a handle is molded onto the lid. This configuration is also ensured by the practical spraying technique. You need to design the inside and outside shape of the injection device only appropriately in order to form a handle both in the area of the cover and, if appropriate, overlapping the cover edge, partially on the outside of the tube. It is also possible to inject gripping tabs, for example on a tear-off membrane in the area of the opening device, in order to make opening particularly easy and, if necessary, also to reclose. On the other hand, the handle on the lid can also be provided so that the end user can grip the liquid pack before and / or after opening it and can transport it by means of a handle. Particularly when the handle is provided beyond the tube, but also in the case when the handle is only in the lid area, this handle can facilitate pouring out to tilt the package.

To design the longitudinal sealing seam explained above, the same technique can be used with paper wall panels to create the cover, inject the gaps to form plastic bridges, add opening devices and, if necessary, handle, without causing sealing problems, even if the longitudinal sealing seam extends over the entire height of the tube extends to the top of the triangular paper wall panel. Any fears, especially with regard to the latter option, when the longitudinal sealing seam is in the paper wall area to form the cover, have proven to be unfounded. The spraying technique can make critical points in the transition from three to one layer without leakage problems to non-critical points, which consequently do not need to be given special attention.

The particularly favorable aspect of the pack according to the invention is therefore the material saving and the good tightness and the property of easy opening of the new package, even gas tightness. The paper wall panels are designed and folded so that always only the desired area of the lid is covered and there are no overlaps. Plastic is injected around the cut lines, which specify the more or less long shape of the triangular wall panels, these cut lines or the gap between adjacent wall panels are injected. The cutting line is conveniently formed by punching when separating two pack blanks that run together through a machine. This punching and cutting can take place both on the paper machine and in the packaging machine. The punching process in the packaging machine is preferred because the latter can be operated more easily in a cycle, so that cutting and punching and the waste can be removed more easily. Paper machines, however, mostly run at very high performance and high speeds, so that the cutting processes there would require greater care.

Figur 1

perspektivisch eine erste Ausführungsform einer fertigen Packung mit ebenem Deckel,

Figur 2

eine ebenfalls perspektivische Darstellung einer fertigen geschlossenen Packung mit vieleckigem Deckel,

Figur 3

eine weitere andere Ausführungsform in perspektivischer Ansicht, wobei eine geschlossene Packung mit kegelstumpfförmigem Deckel und angeformtem Griff gezeigt ist,

Figur 4

die Draufsicht auf zwei gegeneinander gerichtet laufende Zuschnittbahnen nach dem Stanzen,

Figur 5

ein separierter einzelner Zuschnitt für einen kegelförmigen Deckel,

Figur 6

die Draufsicht auf eine ähnliche Packung wie in Figur 1 mit viereckigem Querschnitt und

Figur 7

eine abgebrochene schematische Schnittdarstellung entlang der Linie VII-VII der Figur 6.

Further advantages and possible uses of the present invention result from the following description of preferred exemplary embodiments in conjunction with the drawings. Show it:

Figure 1

in perspective a first embodiment of a finished package with a flat lid,

Figure 2

a perspective view of a finished closed package with a polygonal lid,

Figure 3

another embodiment in perspective view, showing a closed package with a frustoconical lid and molded handle,

Figure 4

the top view of two mutually directed cutting tracks after punching,

Figure 5

a separate individual blank for a conical lid,

Figure 6

the top view of a similar package as in Figure 1 with a square cross-section and

Figure 7

a broken schematic sectional view along the line VII-VII of Figure 6.

From the packaging shown in perspective in FIGS. 1 to 3, one can see the tube, generally designated 1, whose invisible bottom is square, so that there are four side walls, of which only the front side walls 2 and 3 can be seen. Along the upper edge 4 of the tube 1, the cover 5 is formed, which in the case of FIGS. 1 and 2 has a flat surface; in the case of FIG. 3 spans a frustoconical surface.

In the embodiment of Figure 1, the cross section of the tube 1 is square, and both the bottom and the lid 5 are square. In the case of Figure 2, the tube 1 is square only in the lower part near the bottom, while the cover 5 is formed by a violet corner; as is also the case for the embodiment of FIG. 3. There, too, the top edge 4 of the tube 1, which is also the connecting line of the folded edges 4 ', is a polygon in plan view.

The respective lid of the packs shown here is formed from wall panels 6 which have the shape of triangles or, in the case of the embodiment in FIG. 3, trapezoids.

The relatively flat or short triangular wall panels 6 in the embodiment of FIG. 1 result in a cross when these flaps or wall panels 6 are folded inwards about their fold lines 4 ′ into the plane of the cover. The cut edges 7 on the edges of the wall panels 6 lie in the folded state according to FIGS. 1 to 3 closely next to one another, so that they almost touch, but still leave gaps into which the plastic bridges labeled 8 are injected.

Such a plastic bridge 8 between two adjacent wall panels 6 is shown enlarged in cross section in FIG. This is a Double-T profile, but you can also imagine any other type of profile for these bridges 8.

In the exemplary embodiments illustrated in FIGS. 1 to 3 and 6, an opening device, generally designated 9, is also shown. An opening tab 10 or a pouring edge 11 can also be injection molded onto this, for example.

FIGS. 4 and 5 show the blanks lying opposite one another for the respective tube. The zigzag-shaped punching line, which results from the sum of the edges of the wall panels 6, can be seen particularly clearly from FIG. Each outside, i.e. Opposite the triangular wall panels 6 are the usual folding lines for the classic block floor.

In the upper part of FIG. 4, a mandrel 16 with a holding part 17 is also shown schematically rotatable about a dash-dotted center line 15 in order to make it easier to understand how the cut pieces can be placed around the mandrel 16 after being separated so that it supplies the internal injection part whose lower surface in FIG. 4, the wall panels 6 are placed over the folding line 4 'and are sprayed there with the bridges 8 filling the gaps.

FIG. 5 shows an already isolated cut of another embodiment for a plasticizer pack in which the wall panels 6 are triangular and have a greater height than in the embodiment of FIG. 4.

The further processing takes place in the same way as in the other embodiments. The embodiment of FIG. 4 then results, for example, in the package shown in perspective in FIG. 1, the lid of which is square and flat and, for example, may also have the embodiment shown in FIG. 6 with the opening device 9 with gripping tab 10 and pouring edge 11.

Claims (6)

1. A package for liquids, comprising a tube (1) forming the side walls (2,3) and a cover (5) and base provided at the end edges (4) of the tube (1), wherein at least the side walls (2.3) and the base are made of plastic-coated supporting material in the form of paper, cardboard or the like, and the base and cover (5) are formed by folded wall sections (6) integral with the tube (1), and wherein two opposing double-walled triangular sections, connected to the inside of the package, are formed at the base, characterised in that the edges (7) of the plastic-coated wall sections (6) made of paper lie close together in the surface of the cover (5), leaving narrow gaps, and are interconnected in liquid-tight manner by bridges (8) of plastics injected into these gaps, that the opening device (9) is injected in the cover surface, and that the tube (1) has a butt welded seam which is double T shaped in cross-section.
2. The package of claim 1, characterised in that the cover (5) is formed by at least four triangular wall sections (6).
3. The package of claim 1 or 2, characterised in that the cover (5) is flat or conical.
4. The package of any of claims 1 to 3, characterised in that the opening device (9) is mounted in the centre of the cover (5).
5. The package of any of claims 1 to 4, characterised in that the opening device (9) is injected into an aperture punched into at least one paper wall section (6).
6. The package of any of claims 1 to 5, characterised in that a gripping tab (18) is moulded onto the cover (5).

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