EP0077805B1 - Package and apparatus for its manufacturing - Google Patents

Description

The invention relates to a self-supporting, self-supporting, stackable packaging unit that can be flattened after completion according to the preamble of patent claim 1 and a device for producing such a packaging unit according to the preamble of patent claim 6.

A packaging unit according to the preamble of claim 1 is known from DE-A-28 19 869 in the form that the relevant. preferably consists of corrugated cardboard container jacket on its upright wall sections above, inwardly folded rag and on the thus formed substantially flat surface, the edge of the film in question is attached by heat sealing. After the flaps mentioned have been folded up again, the narrower edge sections of the container casing can be folded inwards at the middle vertical grooves, as a result of which the packaging unit itself is given a more economically storable, flat shape. However, it is disadvantageous that a not inconsiderable amount of packing space is lost due to the flaps which surround the window and are folded inwards. Then, once in use, the stored, folded packaging units tend to spring back into the folded state when in use, which makes their handling very difficult.

The invention has for its object to improve this known packaging unit in such a way that the interior of the container shell can be used as completely as possible and that a flawless, dimensionally stable stacking is nevertheless ensured with even easier and space-saving flat foldability. This object is achieved by the characterizing features of claim 1.

Due to the lack of inward-facing rags, almost the entire interior of the container casing is available for packing purposes. The film pulled down on the inside finds at least as good a hold on the container jacket as is the case with the inwardly directed tabs according to DE-A-28 19 869. In addition, the material of these rags is saved. The packaging unit according to the invention can simply be folded in parallelogram fashion along its vertical jacket edges, as a result of which only two wall thicknesses of the container jacket come to lie on top of one another - three in the area of a flap lobe - compared to four or five wall thicknesses in the previously known packaging unit. The latching incisions in the container casing cause the packaging units stacked on top of one another to be locked, thereby not only preventing them from moving relative to one another but also forcing them to maintain their intended shape.

From DE-A-27 21 482 it is already known to have longer upstanding wall sections of the container casing end bluntly on the top in a relevant stackable packaging unit which is open at the top. On the narrow sides, however, inward jacket sections also occur here, and these are followed by the side walls in question as bends, so that there are now four connection points for the jacket instead of a single one. Once the packaging units in question are no longer foldable, they can only be completed by the user. In addition, the film covers the entire jacket blank, which also results in an unnecessary expenditure of material.

Furthermore, DE-B-12 77 113 discloses a stackable and essentially foldable packaging unit, especially for fruit, which also serves as a display package and in which a film on the inside only covers part of its height, for example by welding or gluing upright wall sections of a cardboard jacket is attached. Here, however, this is the case on the upper and lower sides, and the film surfaces stretched tightly over the jacket opening cross-section in the manner of a drumhead should enclose the packaged objects between them. Protection of the packaged objects against side impact is not provided in this way, and the setting up of the prefabricated, folded packaging unit can only take place at the same time as the objects to be packaged are inserted, and also requires the cardboard jacket to be joined by inserting tongues into corresponding slots two separate jacket cuts, which is relatively cumbersome and time consuming.

Then, from DE-B-1 761 693 and DE-A-28 12 636, cups are known which are obtained from an essentially frustoconical shell by sealing a film on the inside, the film reaching out over the upper rim of the cup. In the case of DE-A-28 12 636, the film can also form the sole cup base. In the meantime, these cups, which are naturally not foldable and cannot be stacked after filling, always have an outward-facing roll collar, and the film is deep-drawn to the bottom of the cup.

Claims 2 to 5 contain advantageous developments of the packaging unit according to the invention, the one according to claim 5 also being characterized by particular dimensional stability when it is possible to accommodate a relatively large number of individual objects with shock protection.

A device for producing such packaging units according to the preamble of claim 6 is known from DE-A-28 12 636 is known in the form that the clamped film lying on the roll collar of the cup shell is first heated by a hot air stream and then deep-drawn to the lower end of the container bottom by the punch of the upper tool - which also has a punching tool for separating the applied film becomes, whereupon the applied differential pressure brings them to the entire surface and to stick to the inner wall of the jacket.

In contrast, the object of the device according to the invention is to be able to give the film in the interior of the container jacket below its area of adhesion a desired shape which is independent of the shape of the container jacket, as specified, for example, by claims 2 and 4.

This object is achieved by the characterizing feature of claim 6.

The lower tool in question allows the film to be given any desired trough shape below its adhesion area, including, for example, one in which the trough is at a distance from the container jacket.

The remaining claims contain further advantageous design options for the device in question.

• Figur 1 eine perspektivische Ansicht der betreffenden Verpackungseinheit,
• Figur 2 den Zuschnitt ihres Behältermantels,
• Figur 3 einen Schnitt durch die Verpackungseinheit nach Fig. 1,
• Figur 4 einen ebensolchen Schnitt durch eine Verpackungseinheit in einer abgewandelten Ausführungsform, die zur Aufnahme mehrerer nebeneinanderliegender Einzelobjekte geeignet ist,
• Figur 5 einen Schnitt durch eine Vorrichtung zur Herstellung einer Verpackungseinheit gemäß Fig. 4,
• Figur 6 eine Seitenansicht eines Stapels mehrerer gleichartiger Verpackungseinheiten,
• Figur 7 eine ebensolche Seitenansicht eines Stapels anders dimensionierter Verpackungseinheiten und
• Figur 8 einen Ausschnitt aus dem Behältermantel einer weiteren, stapelbaren Verpackungseinheit.

Examples of the relevant packaging unit and the relevant device are described in more detail below with reference to the drawings. Of which shows

• FIG. 1 shows a perspective view of the relevant packaging unit,
• FIG. 2 shows the cut of your container casing,
• FIG. 3 shows a section through the packaging unit according to FIG. 1,
• FIG. 4 shows a similar section through a packaging unit in a modified embodiment, which is suitable for receiving a plurality of individual objects lying next to one another,
• FIG. 5 shows a section through a device for producing a packaging unit according to FIG. 4,
• FIG. 6 shows a side view of a stack of several similar packaging units,
• FIG. 7 shows a side view of the same type of a stack of differently dimensioned packaging units and
• Figure 8 shows a section of the container jacket of another stackable packaging unit.

The packaging unit 2 shown in FIGS. 1 and 3 essentially consists of a rectangular container jacket 4 made of corrugated cardboard and a film 8 covering its window opening 6 and sealed onto the container jacket.

The blank 10 of the container jacket 4 is shown in a developed form in FIG. 2. As can be seen from this, the container casing has only two longitudinal, essentially rectangular wall sections 12 and 14 and two equally high, rectangular wall sections 16 and 18 on the narrow side, apart from an adhesive tab 20 which laterally adjoins the free end of the wall section 14 and is preferably, as in FIG Fig. 1 shown, comes to rest on the inside of the wall section 16 to close the container jacket. The grooved bending edges which later form the jacket corners are designated by 22 in FIG. In addition, in the region of the longitudinal wall sections 12 and 14, the jacket 4 has sections 24 and 26 which are still opposite one another on the top and bottom sides, the purpose of which is explained in more detail below with reference to FIG. 6. Aside from these minor cutouts, the blank can be made from a cardboard sheet or sheet of paper without any waste.

As can be seen more precisely from FIG. 3, the film 8 covers the top face of the jacket 4 and extends downwards from there, adhering approximately to the upper quarter of the upright wall sections 12 to 18 together with the adhesive tab 20. Below the adhesion area 28 formed in this way, the film extends obliquely inwards in order to form a trough 32 in the lower part of the jacket with a bottom 30 which is flat in this example and which receives the object 34 to be packaged, for example an assembly part. The oblique walls 36 of the trough 32 prevent the object 34 from bumping against the jacket 4.

FIG. 4 shows a somewhat modified embodiment of a packaging unit according to the invention, in which the container jacket 4 is essentially the same, but the film 8 has a plurality of troughs 32 ', which are possibly adjacent to one another in two coordinates, in order to have a plurality of objects 34' against one another within one and the same jacket how to take shockproof against the coat. The individual troughs 32 'are separated from one another by webs 40 formed in the film, which are formed by inclined walls 42 similar to the inclined walls 36. However, in order to stiffen the entire arrangement of troughs 32 'and webs 40, i. H. To prevent possible sagging, the walls 42 can be connected to one another in places, as shown by dashed lines in FIG. 4, for example by welding.

Fig. 5 shows a device 44 for producing a packaging unit according to Fig. 4. This device is preferably located at the end of a conveyor track for previously completed container shells 4, on which the relevant plastic film 8 is placed as a web and which then z. B. passes through equipped with electric radiant heaters. Such a conveyor track, on which the individual container casings follow one another closely side by side, is indicated in the figure as a table, 46.

The device 44 itself has two tools that can be moved vertically relative to one another, namely a lower tool 48 each receiving a jacket 4 and an upper tool 50.

The lower tool 48 is designed according to the desired shape of the film 8 below the adhesion area 28 (FIGS. 3 and 4) and has a shoulder 52 on the outside on which the jacket 4 comes to rest. More precisely, the shoulder 52 carries a sealing strip 54, for example made of silicone rubber, which is adapted to the shape of the lower edge 56 of the jacket, including the cutouts 24 and 26 there, in order to seal it as tightly as possible. Vent channels 58 open out at the bottom of the two trough cavities 60, which are intended to form the troughs 32 'of the film (FIG. 4). An intermediate rib 62 of the lower tool, which is used to form the webs 40 of the film, is, as shown in dashed lines in FIG. 5, recessed in places in order to enable the spot welding of the two web walls 42 described in connection with FIG. 4. If necessary, the tool 48 can, as also indicated by dashed lines, have further ventilation channels 64.

The upper tool 50 essentially consists of a first plate, 66, on the underside of which there is a number of mushroom-shaped stamps 68 corresponding to the number of trough cavities 60, and of a second plate, 72, which can be moved up and down on the shafts 70 of the stamps 68. The plate 66 has an elastic buffer strip 74 on the underside near the edge, with which it can rest on the plate 72. The plate 72 in turn bears on its underside a sealing strip 76 similar to the sealing strip 54 of the lower tool, with which it is able to press the film 8 lying on the frame 4 tightly against the upper frame edge 78. Both strips can in turn be made of silicone rubber. Then the two plates 66 and 72 also have ventilation channels 80 and 82, of which the ventilation channels 82 of the plate 72 consist of a plurality of through-holes surrounding the shafts 70, which, seen in plan view, still open inside the plate 84 of the punch 68.

• Zunächst wird bei auseinandergefahrenen Werkzeugen 48 und 50 von dem Unterwerkzeug 48 in der gezeigten Weise ein Behältermantel 4 zusammen mit der darauf aufliegenden, bis über ihre Erweichungstemperatur erhitzten Folie 8 aufgenommen. Darauf werden Unterwerkzeug 48 und Oberwerkzeug 50 zusammengefahren, wobei zunächst, unter dem Einfluß ihres Eigengewichts und ggf. mit Unterstützung durch nichtgezeigte Federn, die Platte 72 über ihre Dichtleiste 76 auf der Folie und damit auf der Manteloberkante 78 zur Auflage kommt. Im weiteren Verlauf wird die so eingespannte Folie durch die nun nach unten aus der Platte 72 heraustretenden Vorsprünge 68 gedehnt, wobei sie bereits in die Muldenhohlräume 60 eintritt. Dabei kühlen sich die mit den Stempeln 68 zur Berührung kommenden Folienpartien sogleich ab. wodurch sie im wesentlichen ihre ursprüngliche Wandstärke behalten. Wie ersichtlich, ist dies im Bodenbereich der Mulden 32' der Fall, wo die Folie beim Gebrauch durch die dort aufliegenden Objekte 34' am meisten beansprucht sein wird.

The two tools 48 and 50 are not heated. As described above, they can even be chilled. Now use them as follows:

• First, when the tools 48 and 50 have moved apart, the lower tool 48 receives a container jacket 4 in the manner shown, together with the film 8 lying thereon and heated to its softening temperature. Then the lower tool 48 and the upper tool 50 are moved together, the plate 72 first coming into contact with its sealing strip 76 on the film and thus on the upper edge 78 of the casing, under the influence of its own weight and possibly with the support of springs (not shown). In the further course, the film clamped in this way is stretched by the projections 68 now emerging downward from the plate 72, it already entering the hollow cavities 60. The film parts coming into contact with the stamps 68 cool down immediately. which essentially keeps their original wall thickness. As can be seen, this is the case in the bottom region of the depressions 32 ', where the film will be most stressed in use by the objects 34' lying there.

Towards the end of the counter-movement of the tools 48 and 50, the plate 66 comes to rest on the plate 72 via its buffer strip 74, as shown in the figure, as a result of which the latter is additionally pressed against the upper edge 78 of the jacket. Now a differential pressure is applied by mediating the ventilation or ventilation channels 58, 64, 80 and 82, be it by suctioning off via channels 58 and 64, or by blowing air through channels 80 and 82 or both. In any case, this differential pressure has the consequence that the film lies above the lower tool in the adhesion area 28 on the inner wall of the container casing 4 in order to weld to it as well as to the casing upper edge 78, if necessary. Furthermore, due to the differential pressure, the already stretched film fits snugly against the lower tool without causing wrinkles or similar, sometimes observed disturbances. Immediately upon touching the lower tool, the film section in question cools down, whereby it permanently assumes the shape of the lower tool.

To separate the relevant film 8 from the supplied film web, an electrically heated wire 86 can be attached to the side of the plate 66, as shown, which runs through the film web towards the end of the downward stroke of the plate. When the tools 48 and 50 are moved apart again, the finished packaging unit is obtained. as shown in Fig. 4.

In order to prevent the film from sticking to the lower tool and also to the punches 68 of the upper tool, the surfaces thereof that come into contact with the film can be coated with a conventional release agent, such as. B. tetrafluoroethylene, coated.

As previously mentioned, the film is heated as it is fed to device 44. The tools 48 and 50 absorb the heat of the film when it comes into contact with it, causing the film to solidify in its form. In order to make this possible in continuous production in the long term, the tools may have to be cooled. One possibility for cooling of this type is to equip the tools with cooling water channels which are connected to corresponding supply and discharge lines, if necessary via hoses. Then the tools can also carry cooling fins on the outside, which, if necessary via suitably arranged guide channels, are blasted with air via a blower. Such measures are common in technology, so that a more detailed description is unnecessary here.

Fig. 6 shows a stack-like arrangement of several identical packaging units of the preceding described type, which can continue, for example on a pallet, upwards as well as to the sides. As can be seen, the packaging units 2 lying one above the other, which have a specific length / width ratio for this purpose, are arranged crosswise, their cutouts 24 and 26 interlocking in a form-fitting manner. As a result, the stack, like each individual packaging unit, is held securely, even as long as the stack is not yet secured to the pallet by a shrink film or the like. This can be very useful for in-house transportation.

As can be seen from FIG. 7, in the case of a leaner format of the packaging units 2, these can also be stacked in such a way that they overlap one another in such a way that over individual packaging units 2, (which are, however, designed in the same way as the other), joints of the above and underlying packaging units come to rest. Of course, as shown, this can have the consequence that the cutouts 24 and 26 of the packaging units in question must be arranged asymmetrically with respect to the vertical central axis of their longitudinal wall sections 12 and 14, so that when stacking it must be ensured that the packaging units are included a certain orientation.

Fig. 8 shows one way of circumventing this by continuously providing the upper and lower edges of the longitudinal wall sections 12 and 14 (only one of which is shown here in part) with - in this example - sawtooth-like cutouts, 88. Of course, others also come, such as B. rectangular, trapezoidal or rounded tooth shapes in question.

Another use of packaging units according to the invention is to place them on top of or against each other in pairs to form a shock-absorbing packaging, preferably in such a way that their cutouts 24, 26 and 88 interlock again. Then the container jacket can also be made of a flat material other than corrugated cardboard, for example a corresponding plastic product or u. U. also cardboard exist. After all, the film used need not be a self-adhesive film. In this case, the frame wall can be coated at an appropriate point with an adhesive, preferably a hot melt, to which the film, for example a polypropylene film, adheres in the case of the described or a similar treatment.

Claims (10)

1. Self-supporting stackable packaging unit (2) which is open at the top and after production can be laid flat again, consisting of a container shell (4) of sheet material, such as corrugated board, having upright wall portions (12-18), and adhering thereto a troughed plastic sheet (8) deep-drawn to the shell center corresponding to the form of the objects to be accommodated (34, 34'), characterized in that the container shell (4) comprises only the upright wall portions (12-18), that the foil (8) adheres to the inside of the container shell (4) over a portion of its height proceeding from the upper edge of the container shell and that the container shell (4) has detent notches (24, 26, 88) at its upper and/or lower edge.

2. Packaging unit according to claim 1, characterized in that the trough of the sheet (8) beneath its adhering region (28) is spaced from the container shell (4).

3. Packaging unit according to claim 1 or 2, characterized in that at least two detent notches (24, 26) in every two opposite wall portions (12, 14) have a spacing from each other which corresponds to the spacing of said wall portions from each other.

4. Packaging unit according to any one of the preceding claims, characterized in that the detent notches (88) form a continuous serration.

5. Packaging unit according to any one of the preceding claims, characterized in that the sheet (8) comprises in a manner known per se in two coordinates, possibly offset with respect to each other, in each case a plurality of troughs (32') separated by hollow webs (40) and that at least a part of the webs is stiffened by local joining together of the two opposite web walls (42).

6. Apparatus for making packaging units (2) open at the top from a container shell (4) having only upright wall portions (12-14) and deep-drawn plastic sheet (8), comprising a heating means, a clamping and deep-drawing means (44) for the sheet which receives the container shell (4) with applied plastic sheet (8) and is substantially sealed outwardly and which comprises an upper tool (50) having at least one unheated punch (68), and a fan which is connected to said means (44) in such a manner that a downwardly acting differential pressure can be applied to the clamped sheet (8), characterized in that the clamping and deep-drawing means (44) comprises a shaping lower tool (48) which is immersed up to part of its height in the container shell (4) and moreover adapted to a desired trough form of the sheet (8).

7. Apparatus according to claim 6, characterized in that ribs (62) of the lower tool (48) forming webs (40) in the troughed sheet area are locally cut out in such a manner that the two opposite web walls (42) of the sheet (8) can join together under the action of the differential pressure applied to the clamping means (44).

8. Apparatus according to claim 6 or 7, characterized in that the punch (68) is disposed on its own plate (66) of the upper tool (50) on which a plate (72) reciprocal up and down and adapted to be pressed against the upper edge (78) of the container shell (4) is suspended, and that the latter plate (72) is adapted to be pressed by the former plate (66) on approaching the end position thereof by way of a resilient member (74) against the upper edge (78) of the container shell.

9. Apparatus according to any one of claims 6 to 8, characterized in that the heating means is part of a supply means (46) for successive container shells (4) and said supply means further comprises a means for applying the sheet (8) as continuous web to the successive container shells (4).

10. Apparatus according to claim 9, characterized in that a cutting means (86) for the sheet web is connected to the punch (68) of the upper tool (50).

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