EP0185325B1 - Package for liquids - Google Patents

Description

The invention relates to a packaging made of a carrier material coated with a thermoplastic, such as e.g. Cardboard, for liquids or the like with a tubular main body with bottom and lid with gable fold, which has a pouring spout that can be opened by opening sealing seams, in the sealing area of which, in addition to sealing fields with strong adhesive force, those with low adhesive force are arranged for peeling apart the sealing fields, whereby Sealing field with low adhesive force is formed by a pattern of spaced-apart raised areas that alternate with adjacent and lower-lying fields.

A pack of this type is known from GB-A-1,114,620. This container with gable closure is about achieving a good seal without delamination problems when opening. This is solved in the known case by providing a full cut through the material in a wall of the gable closure, above the gable surface and the adjacent triangular fields. An outer zone with a roughened surface is arranged in a region between this continuous slot and a fold line adjoining the gable surface and the triangular fields. This roughening can be achieved by abrasion, scratching, knurling or cutting. The surface treated in this way allows the heat to flow away in the direction of neighboring non-roughened areas, because the roughening of the surface has the effect of a certain temperature insulation. This creates an area with less adhesive force outside the fold line and also areas with stronger adhesive force when the plastic-coated paper is heated between the sealing jaws. The cut completely through the material next to the area with the roughened surface ensures that the material adheres to the gable closure in the area of the strong adhesive force and thus also in the area of the fold line after opening the pouring device, while tearing and opening over the area with the low adhesive force. Unfortunately, the areas around the fold line are sealed with strong adhesive force, so that the package can sometimes be difficult to open.

In addition, in the case of liquid packs, the introduction of cuts through the entire material and also the surface damage, even in areas which are more or less closed by sealing, is critical insofar as, in the case of pressure loads, the possibility is not excluded that liquid can come into contact with the unprotected paper parts comes and this softens. It would therefore be advisable to at least avoid the continuous cut and, if possible, not to avoid the plastic seal deliberately damaging.

In US-A-3,319,868 it has already been proposed to create areas with lower adhesive strength by applying sealing deteriorating agents, for example based on nitrocellulose. In addition, attempts have been made to achieve the low adhesive strength by coating the areas in question with a special plastic or else in that the sealing areas with low adhesive strength are not heated to a comparable extent as other sealing areas which are said to have a strong adhesive force. However, complicated tools are required for this, and the application of separate plastics or sealing deteriorating agents is expensive. The areas of lower adhesive force always extend to the strips above the fold line on the gable surface and the triangular fields with the resulting risk of difficult opening.

The object of the invention is therefore to improve the packaging of the type mentioned in such a way that one is neither dependent on sealing deterioration agents nor on complicated tools and also not on continuous cuts which endanger the material, in particular the opening of the packaging should be facilitated.

This object is achieved in that the area with low adhesive force extends into the gable surface and into the lateral triangular fields of the gable. Without a cut through the material and without damaging the plastic seal on the surface of the carrier material, these measures result in areas with weaker adhesive strength extending beyond the fold line mentioned and thus eliminating the risk that even outside the double cardboard strip, i.e. beyond the fold line, sealed with strong adhesive force and it is difficult to open, even if conventional sealing devices are used.

It is expedient if the raised areas are formed by periodically intersecting straight and / or curved ribs, the fields in between being lower or vice versa. Due to the multitude of ribs crossing each other and the fields lying between them, lying lower or higher, any gradation of adhesive force can be achieved in the sealing area in question, namely by controlling the number of ribs or their width, right down to the gable surface. Through the pattern of fields of different heights, a liquid-tight sealing of the pouring opening can be achieved, although the opening forces remain low in the desired areas. The simple method for preparing the relevant sealing fields can be seen.

In a further embodiment, it is advantageous if the raised fields are a plurality of points and / or smaller areas arranged side by side, the circumference of which is angular and / or round.

Experiments have shown that sealing jaws with the rib patterns or dot patterns in question have not achieved the desired success because the softness of the carrier material has compensated for this by leveling this pattern towards the inside of the cardboard layer. It is therefore better if the pre-treatment of the blank or the web from which the blank is cut, e.g. in connection with the creasing and possibly pre-punching, the recesses next to the raised surface parts are provided by pre-treatment so that in the welding station with e.g. smooth sealing jaws the fields with the patterns are introduced. Then the sealing is advantageously only possible along these raised surface parts, and the deeper lying sections next to it remain unsealed.

It is also advantageous if the sealing field located on the pouring spout has a recess with low adhesive force. This avoids that after opening and reclosing the adhesion of the sealing surfaces pressed together during reclosing becomes too strong, so that the user has difficulties with the second and third opening. It has proven to be particularly expedient if, according to the invention, the recess is formed symmetrically to the tip of the pouring spout in the form of a bulge, because this makes it easier to produce the wall fields forming the pouring spout. A bulge is characterized in that a border line of the same is located on the outer edge.

Such a bulge can be created from a paper wall, for example, by cutting out a round piece on the outside edge with scissors; or a rectangular box; or cut out a jagged area that looks like a triangle. The more general term "recess", on the other hand, instead of the concrete exemplary embodiments mentioned above, also provides holes or openings which are completely contained in the wall field in question, without being open towards the edge. The bulge, however, is always open towards the edge. It is easier to manufacture, in particular if, in a further advantageous embodiment of the invention, the recess is triangular and the apex of this triangle forms the tip of the pouring spout. The hypotenuse opposite the apex could then, for example, be the cut off edge of this sealing field before the reduction. By reducing the sealing field with low adhesive force, its adhesive force is reduced even further in a very simple manner.

Another embodiment of the invention is further characterized in that fold lines are arranged in the sealing fields of low adhesive force which are attached to the two inclined surfaces forming the gable-shaped lid of the packaging and which preferably run vertically into the double cardboard strips. This creates a differently designed and easy-to-create pouring spout that is easy for the end user to open and use.

To create sealed seams with low adhesive force in the area of these sealed seams, the invention depresses certain parts of the coated web in such a way that they do not participate in the welding or sealing process. This reduces the overall sealing area, and consequently the adhesive force of the sealing seam ultimately produced also decreases.

Figur 1

eine perspektivische Ansicht einer Verpackung mit giebelförmigem Deckel im verschlossenen Zustand,

Figur 2

die gleiche Verpackung der Figur 1, wobei jedoch der erste Schritt zum Öffnen der Ausgießöffnung dargestellt ist,

Figur 3

abgebrochen und wiederum perspektivisch die Draufsicht auf den giebelförmigen Deckel der Verpackung nach dem vollständigen Öffnen,

Figur 4

eine abgebrochene Seitenansicht des oberen Bereiches eines flachgelegten Zuschnittes nach Figur 1 mit den Faltlinien und den Siegelfeldern geringer Haftkraft,

Figur 5

abgebrochen und stärker schematisiert die gleiche Ansicht wie Figur 4 zur Verdeutlichung beim Vergleich mit dem Herstellungswerkzeug,

Figur 6

eine Draufsicht auf das Herstellungswerkzeug, d.h. die Prägerolle,

Figur 7

die Oberfläche der Prägerolle in flachgelegten Zustand, wobei die Enden abgebrochen sind,

Figur 8

die Seitenansicht einer anderen Ausführungsform, in der Darstellung ähnlich wie Figur 4 nach der oben beschriebenen Ausführungsform und

Figur 9

eine Einzelheit des Musters bei einer bevorzugten Ausführungsform der Prägerolle gemäß Kreisausschnitt IX in Figur 7.

Further advantages, preferred features and possible applications of the present invention result from the following description in conjunction with the drawings. Show it:

Figure 1

a perspective view of a package with a gable-shaped lid in the closed state,

Figure 2

the same packaging of Figure 1, but showing the first step to open the pouring spout,

Figure 3

broken off and again a perspective top view of the gable-shaped lid of the packaging after fully opening,

Figure 4

2 shows a broken side view of the upper area of a flat blank according to FIG. 1 with the fold lines and the sealing fields of low adhesive force,

Figure 5

broken off and more schematically the same view as FIG. 4 for clarification when compared with the production tool,

Figure 6

a plan view of the manufacturing tool, ie the embossing roller,

Figure 7

the surface of the embossing roller in a flat state, the ends being broken off,

Figure 8

the side view of another embodiment, in the representation similar to Figure 4 according to the embodiment described above and

Figure 9

a detail of the pattern in a preferred embodiment of the embossing roller according to circular section IX in Figure 7.

The packaging shown in perspective in FIGS. 1 to 3 is generally designated C. It has a tubular main body, generally designated 20, with a quadrangular cross-section, a base 21 and a gable-shaped lid, generally designated 22. This consists of two inclined surfaces 24, 25 and a double-layer cardboard strip, one layer of which is designated 29 and the opposite one is designated by 26.

According to FIG. 4, the tubular main body 20 is closed along the sealing seam 38. The folded gable surfaces 31 and 32 lying approximately perpendicular to the wall surfaces 24 and 25 are laterally connected to triangular fields 34, 35 and 36, 37, respectively, while fields 30, 41 and 42 are provided towards the opening side to form the ridge seam.

The entire packaging consists of paper or cardboard coated with thermoplastic on both sides, so that with a corresponding design of the sealing tools, a completely liquid-tight closing of the gable-shaped lid of the package is possible.

However, in areas 39, 40, 48 and 49 a sealing field of low adhesive force is to be generated, which is why these areas are provided with the special pattern 46, 47 and 49, respectively.

After sealing, which takes place weaker over these areas 39, 40, 48 and 49 in such a way that these fields have a lower adhesive force and are consequently peelable, the pack can be brought into the position shown in FIG. 2 by a first step.

In order to avoid possible re-adhesion of the sealing fields 48, 49, 39 and 40 of low adhesive force when the container is opened, the embodiment according to FIG. 8 is provided. There is a prefabricated cardboard material, i.e. 4 shows a broken-off blank according to FIG. 4, but with small changes, so that the packaging from the blank according to FIG. 8 represents a slightly modified embodiment compared to the packaging that is created from the blank of FIG. Identical fields and parts of FIG. 8 for FIG. 4 are provided with the same reference numbers, but additionally have an apostrophe. In order to further reduce the adhesive force, the sealing fields 39 ', 40' have been reduced, e.g. by cutting off a middle part 50, which is shown in FIG. 8 with oblique hatching and with triangular boundary lines. Although the shape of such a cut-off part 50 can be different, it is particularly useful to design the section in a V-shape, the lower tip of the "V", which is denoted by 51 in FIG. 8, lying on a vertical fold line 52, which starts from the intersection between the corresponding fold lines 53, 54 in the upper wall panels 31 ', 34' of the preformed cardboard material. The V-shaped section 50 preferably has the shape of an isosceles triangle, the apex 51 of which lies on the fold line 52. According to a practical embodiment, e.g. the hypotenuse or base is approximately 25 mm and a corresponding triangle height is 4 to 5 mm.

According to the embodiment of the cardboard material shown in FIG. 8, which has been changed from FIG. 4, the two wall panels 24 'and 25' arranged at the top of the packaging can also be provided with fold lines 55 and 56, some of which are arranged within corresponding sealing fields 48 'and 49' with a lower adhesive force. These extra folding lines 55 and 56 preferably extend vertically upward in the illustration in FIG. 8 and represent extensions corresponding to the folding lines 57 and 58 within the wall panels 24 'and 25'. This forms a different and lighter pouring spout when the filled and sealed packaging C should be opened and their contents should be poured out.

From FIG. 2 it can be seen that the peelable sealing surface in the area of the special pattern 46 (for example rhombus-shaped depressions arranged at a distance from one another) can be opened in such a way that the two triangular fields 34 and 35 are pulled apart.

FIG. 3 then shows the state after the pouring device has opened completely, namely the lip 45 of the pouring spout 44 serving as the pouring spout being folded out by loosening the pretreated sealing fields 47 and 49.

In Figure 5, the cutting of Figure 4 is repeated again, but more schematically and shown so that an easy comparison with the manufacturing tool is possible. The sealing fields with low adhesive force are again designated 39 in the middle on the right side and 40 on the left side, 48 and 49 on the outside on the sides.

An embossing roller 1 is used to produce such a pattern. A line of sealing fields 49 ', 40', 39 'and 48' arranged one behind the other is arranged on half the circumference of the embossing roller 1, ie over an area of somewhat more than 180 °. In Figure 6 you can see that in a line Pattern fields 49 ', 40', 39 'and 48' arranged one behind the other and at least partially at a distance from one another, viewed from top to bottom.

If the embossing roll 1 is unwound in one plane, the surface is shown, as shown in FIG. 7, the two raised pattern fields 39 'and 40', which are directly adjacent to one another without a distance, being approximately in the middle, to the right and left thereof the pattern fields 48 'and 49' are spaced apart. To the outside, further to the right and left, the remaining circumference of the embossing roll 1 has broken off, because there is no raised pattern field.

The detail IX in Figure 7 is shown in Figure 9. Overall, this is the raised pattern field 40 ', in which raised fields 5 (this is the coherent main surface) alternate with lower-lying fields 6 in the form of rhombuses. At an angle of 60 ° to the axis of the embossing roller 1 there is a line of spaced-apart, periodically arranged rhombic depressions on the circumferential surface in such a way that the desired pattern results from the juxtaposition of a large number of such rhombic rows.

This pattern according to FIG. 9 can also be interpreted differently in that straight ribs intersect as raised surfaces 5 in such a way that the rhombic, lower-lying fields 6 remain between them.

In another interpretation, in which FIG. 9 is created, for example, as a section of a sealing field with low adhesive force using a reverse tool, in which the rhombus-shaped surfaces 6 are raised and the crossing ribs 5 running next to these lie lower, a sealing field is obtained , as shown in FIG. 5 with 39, 40, 48, 49, in which the pattern to be thought of according to FIG. 9 alternates from the raised areas 6 with the adjacent and lower-lying fields 5.

Claims (7)

1. A package made of a supporting material such as cardboard, coated with a thermoplastic material, for liquids or the like, comprising a tubular main body 20 with a base 21 and a cover 24-26, 29 which is folded into a ridge shape and has a pouring spout 44 which can be opened by opening sealed seams, wherein the sealing region of the spout contains sealing sections 30, 41, 42 with strong adhesive power and adjacent sections 39, 40, 48, 49 with low adhesive power for peeling the sealing sections apart, and wherein the sealing section 39,40 with low adhesive power is formed by a pattern of raised surfaces 6 at a spacing a from one another, alternating with adjacent sections 5 at a lower level, characterised in that the region with low adhesive power extends into the ridge area 31 and into the lateral triangular sections 34, 35 of the ridge.
2. The package of claim 1, characterised in that the raised surfaces are formed by periodically intersecting straight and/or bent ribs, with sections 5 at a lower level between them or vice versa.
3. The package of claim 1, characterised in that the raised surfaces are a plurality of adjacent spots and/or quite small* areas 5 with an angular and/or round periphery.
   *alternative translation: smaller
4. The package of claim 1, characterised in that the sealing section 39, 40 with low adhesive power at the pouring spout 44 contains a recess 50.
5. The package of claim 4, characterised in that the recess 50 is made symmetrically with the tip (fold line 52) of the pouring nozzle 4, in the form of an indentation.
6. The package of claim 4 or 5, characterised in that the recess 50 is triangular and the apex 51 of the triangle forms the tip of the pouring nozzle 44.
7. The package of claim 1, characterised in that fold lines 55, 56 are located in the sealing sections 48', 49' of low adhesive power, provided on the two inclined surfaces 24', 25' which form the ridge-shaped cover of the package (C), the fold lines preferably running perpendicularly into the doubled-over cardboard strip 26, 29.

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