EP2888170B1 - Method and apparatus for packaging units of combined groups of objects - Google Patents

Description

• Umhüllen der jeweiligen Verpackungseinheit in ihrer Laufrichtung auf einer Transportstrecke mit einer Folie unter gleichzeitiger Bildung eines Folienüberschlages sowie von jeweils querrandseitig über die Verpackungseinheit überstehenden Faltlaschen und
• Anlegen der vertikalen ausgerichteten Faltlaschen an die Verpackungseinheit beim Durchlauf durch die Falteinheit sowie anschließende und/oder gleichzeitige gegenseitige Fixierung der Faltlaschen unter Bildung eines allseits geschlossenen Folieneinschlages.

The invention relates to a method for packaging groups of objects combined into packaging units, with the steps

• Enveloping the respective packaging unit in its running direction on a transport path with a film with simultaneous formation of a film overlap and each transverse edge side on the packaging unit protruding folding flaps and
• Applying the vertically aligned folding tabs to the packaging unit when passing through the folding unit and subsequent and / or simultaneous mutual fixation of the folding tabs to form a film wrap closed on all sides.

The groups of objects grouped together to form the packaging units are usually bottles, in particular plastic bottles, cans, etc. The film, which is typically designed as a plastic film, is finally shrunk so that the articles form a stable packaging unit. In addition, the objects are mutually fixed by means of the shrunken film.

In a method of the type described above, as described in the WO 2005/080206 A1 is presented, pairs of folding tabs are realized, which are folded about horizontal or vertical axes. Following the folding process, a welding process takes place by the action of heat. In such a procedure, there is the problem that the folding tabs in the course of the action of heat and the associated shrinkage process can at least partially "rise" or the all-round film impact experienced unintentional opening in the folding tabs. In the extreme case, this can lead to the items combined with the aid of the foil wrapping no longer being able to be transported properly and / or falling out of the film wrapping. Such phenomena are observed especially in articles with increased weight, for example, beverage cans or generally canned products.

For a comparable procedure in the context of the closest EP 1 059 236 A1 Primarily cigarette packs are wrapped with a foil. In this case, there is also a prefixing vertically aligned folding straps. For this purpose, sealing tools are provided in each case act on the held in pockets packaging units accordingly. The bags are found in rotating disks.

As part of the DE 10 2008 052 633 A1 the individual folding tabs are mutually fixed in the overlap area by existing or introduced adhesive or by a weld. Subsequently, a shrinking process takes place in a shrink tunnel. As a result, overall the stability of the packaging unit produced in this way is significantly increased over previous embodiments. However, in this case as well, it can ultimately not be ruled out that individual folding flaps will inadvertently be opened during the subsequent shrinking process due to the deformation associated with the shrinkage. This is where the invention starts.

The invention is based on the technical problem of further developing such a method and an associated device so that a perfect closed film wrapping of the packaging unit is made available and, in particular, unintentional openings of the folding straps during shrinkage are avoided.

To solve this technical problem is provided in a generic method that the vertically aligned folding tabs are mutually positioned and pre-fixed by heat with the aid of a longitudinal heat source and then the packaging unit is fixed in total by heat, the folding tabs in the course of prefixing at least partially laminated become.

That is, the folding flaps experience a mutual connection with each other.

This connection is designed so that the folding tabs can not unintentionally "open" during the subsequent final fixing and the associated shrinking process. As a rule, the prefixing is carried out in such a way that the base films of the folding tabs to be joined are at least partially covered by a corresponding surface finish or treatment, in particular a Corona treatment, are suitable to connect by lamination together without the need for another adhesive or adhesive.

In this process, the folding tabs according to the invention and at the same time a mutual positioning. As a result, the invention ensures that the folding tabs maintain their relative position to one another during their prefixing or lamination and at the end of the prefixing ensure that the folding tabs ensure perfect lateral closure of the foil insert. This closure remains consistent. Now, if the packaging unit thus prepared with the film wrapping in, for example, a shrink tunnel for final fixing, then the closure of the folding tabs can not be opened (more) with each other. Rather, this final fixation merely ensures that the film impact is shrunk overall, although the lateral closure by the folding tabs remains largely uninfluenced by this. In the context of the invention, therefore, there is a separation of the method and the device between, on the one hand, the prefixing or lamination and, on the other hand, the final fixing or shrinkage. As a result, the overall energy input in the area of the folding tabs can be increased compared to previous approaches.

The increased and targeted introduction of energy in the area of the folding tabs by the prefixing that takes place here ensures that the folding tabs retain their lateral closure of the packaging unit achieved in this way and do not undergo any unintentional opening during the subsequent shrinking operation or final fixing. In addition, the increased energy input in the area of the folding tabs takes into account the fact that the film impact in this area is multi-layered and the individual folding tabs have to be laminated together before the actual shrinkage can take place. As a result, the film wrapped around the packaging unit or the film wrapping optimally maintains its position during the entire processing operation. Here are the main benefits.

In general, the vertical folding tabs are prefixed into a shrink tunnel following the folding unit and before the packaging unit has passed. In principle, however, the prefixing can also be carried out in the folding unit together with the actual folding. As a rule, however, the folding unit on the one hand and a prefixing unit on the other hand and finally an end fixing unit are designed separately and independently of one another.

The folding tabs are prefixed by means of the longitudinal heat source. As already explained, in the course of prefixing, the folding tabs not only experience a mutual adhesive connection, but also a mutual positioning. That is, the positioning and lamination of the folding tabs take place at the same time. The positioning is regularly ensured by a pressing element, with the help of which the folding tabs are pressed against the packaging unit. The pressing element ensures that the folding tabs applied to the packaging unit by means of the folding unit remain in this position in contact with the packaging unit during the prefixing. At the same time, the pressing element in this context may have the required heat for the lamination. To be able to perform the prefixing properly in this context, the heat source and / or the already mentioned pressure element are regularly equipped with an anti-adhesive coating. This makes it possible to prevent any adhesion of the folding tabs to the heat source or the pressure element when passing through the associated prefixing unit.

The invention also relates to a device for packaging groups of articles combined into packaging units, as explained in more detail in claims 5 et seqq. The device in question is particularly suitable for carrying out the method described. As already explained, according to the invention, the folding unit, the prefixing unit and finally the final fixing unit are usually designed separately from one another. In addition, the design is largely such that the prefixing unit connects to the folding unit and finally follows the final fixing unit of the prefixing unit. As a rule, the procedure is also such that the folding unit, the prefixing unit and the final fixing unit directly adjoin one another in the running direction of the packaging unit.

Moreover, it has proven useful if the prefixing unit is equipped with its own heat source. This heat source is the extended heat source. It is advantageous if the heat source is energized completely or partially by the Endfixiereinheit. That is, the heat source of Vorfixiereinheit gets all or part of their heat energy from the Endfixiereinheit or at this point usually realized additional own heat source. For this purpose, the heat source of the prefixing unit may extend into the final fixing unit.

To ensure that the folding flaps are properly pre-fixed, positioned and, in particular, irreversibly laminated, the pre-fixing unit ensures that the folding flaps are subjected to mechanical and heat simultaneously. The mechanical loading of the folding tabs within the prefixing unit is generally carried out with the aid of the at least one pressing element. Alternatively or additionally, however, the folding tabs can also be acted upon in a suitable fluid-mechanical manner for mutual positioning and alignment with respect to the packaging unit.

In order to prevent adhesion of the folding tabs on the pressure element and / or the heat source mutually laminated when passing the prefixing unit, the pressure element and / or the heat source is provided with a coating on at least its side facing the folding tabs. This coating prevents or avoids such buildup. The Endfixiereinheit is regularly a shrink tunnel or a comparable element, which ensures the desired shrinkage of the wrapped around the packaging unit film.

As a result, a method and a device for packaging groups of objects combined into packaging units are described, with the aid of which a secure closure of the articles and a film closure that is closed on all sides are possible. As a result, the method and the device are predestined for being able to produce packaging units of, for example, cans or other articles of significant weight, in which particular demands are placed on the film wrapping in terms of tear resistance, in particular during transport.

By prefixing carried out in the context of the invention, including simultaneous positioning of the folding tabs in the prefixing, it is ensured that the film impact during the subsequent shrinking process is not unintentionally opened in the area of the folding tabs. Rather, the invention ensures that the film wrapping is designed to be closed overall and also retains this closed design. Here are the main benefits.

Fig. 1

die Vorrichtung schematisch mit Falteinheit und Vorfixiereinheit,

Fig. 2

die Vorrichtung nach Fig. 1 ergänzt um die Endfixiereinheit in einer ersten Variante

Fig. 3

abgewandelte Ausführungsform der Vorfixiereinheit und

Fig. 4A - 4D

weitere Abwandlungsformen der Vorfixiereinheit schematisch.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment; show it:

Fig. 1

the device schematically with folding unit and prefixing unit,

Fig. 2

the device after Fig. 1 supplemented by the final fixing unit in a first variant

Fig. 3

modified embodiment of Vorfixiereinheit and

Fig. 4A - 4D

Further modifications of the prefixing unit schematically.

In the Fig. 1 and 2 In principle, a device for packaging objects 1 is shown. In fact, the articles 1 are grouped together and thus form packaging units 2. The articles 1 are, in the exemplary embodiment and not limited to cans, which have been combined to form the relevant group. The doses may have a matrix-like arrangement in the example case. To summarize the objects 1 or cans to be wrapped to the packaging unit 2 and to position the cans accordingly the reproduced device corresponding sorting and alignment devices are connected upstream, which are not shown in detail, however. In fact, at this point may be worked with stops and / or support rods.

Also not shown in the figures is a storage drum for a film 3, in the embodiment, a plastic film 3, which has been wrapped around the packaging unit 2, as the Fig. 1 represents. The plastic film 3 may be made of PE, PET, PP, etc., wherein the plastic in question is shrinkable. The wrapping of the respective packaging unit 2 takes place in the running direction L during the transport of the group of objects 1 over the transport path T. For this purpose, a film roll may be cut off and passed through a slot on the transport path T. The front end of the film roll is run over by the packaging unit 2. When the packaging unit 2 continues on the transport path T, a film driver rod travels under the film roll from below and describes a circular path or generally a circular path over the packaging unit 2 in the running direction L. Thereafter, the film driver rod together with the rear end of the film roll enters a further slot , When transporting the so wrapped packing unit T in the direction L, this moves over the slot in question and thus pulls the front end of the film roll under him.

In this way, the packaging unit 2 stands on the overlapping ends of the film roll and at the same time a film flashover 4 of the two ends of the film roll is defined. For further details of the described envelope is on the DE 42 07 725 A1 Referenced.

When wrapping the respective packaging unit 2 in its direction of travel L on the transport path T with the aid of the film 3 to form the film overlap 4 are also transverse edge side of the packaging unit 2 protruding folding tabs 5, 6, 7, 8 defined. The two folding tabs 5, 6 lie opposite one another and form an associated first folding tab pair 5, 6. The relevant folding tabs 5, 6 are applied to the packaging unit 2 in question by a predominantly vertical folding process when the packaging unit 2 enters a folding unit 9.

In addition to the two folding tabs 5, 6 or the first folding tab pair 5, 6, two further folding tabs 7, 8 are realized, which are also opposite. The two further folding tabs 7, 8 define a second folding tab pair 7, 8. For its production, the two opposite folding tabs 7, 8 are applied to the packaging unit 2 by a predominantly horizontal folding operation. The respective folding processes are characterized by corresponding folding lines in the Fig. 1 indicated.

In the context of the illustrated embodiment, the folding unit 9 is for applying the folding tabs 5, 6, 7, 8 to the packaging unit 2 in detail from stationary folding elements 10, 1 and with the packaging unit 2 mitbewegten folding elements 12, 13 together. The respective moving folding elements 12, 13 are moved predominantly synchronously together with the packaging unit 2 moved along the transport path T in the running direction L.

The stationary folding elements 10, 11 are, on the one hand, a pressure rail 10 and, on the other hand, a slanted guide 11. The co-moving folding elements 12, 13 are designed, on the one hand, as a rotating folding disk 12 and, on the other hand, as a folding drum 13 moving along with the packaging unit 2. In any case, the folding tabs 5, 6, 7, 8 are applied to the packaging unit 2 after passing through the folding unit 9, as basically in the Figs. 4A to 4D is shown. Any details of the folding process are not relevant in this context. Also not on how the folding unit 9 is constructed in detail.

It can be seen that the folding unit 9 is preceded by a previously described and not further identified wrapping unit, by means of which the respective packaging unit 2 is enveloped with the film 3 on the transport path T in the running direction L. The folding unit 9 adjoins the wrapping unit, which ensures that the folding tabs 5, 6, 7, 8 projecting beyond the packaging unit 2 are applied to the packaging unit 2. The folding tabs 5, 6, 7, 8 are applied by means of the folding unit 9 to the packaging unit 2 during the passage of the packaging unit 2 through the folding unit 9.

In addition, a fixing device 14, 15; 16 realized. The fixing device 14, 15; 16 serves at least for mutual fixation of the folding tabs 5, 6, 7, 8 with each other. In the context of the embodiment, the fixing device 14, 15; 16 from a Vorfixiereinheit 14, 15 and an Endfixiereinheit 16 together. In the exemplary embodiment, and not restricting, the end fixing unit 16 is a shrink tunnel 16, which is equipped in its interior with its own heat source, for example a hot air blower with nozzles, an infrared radiator, etc., and ensures that the film looped around the packaging unit 2 3 shrinks.

In contrast, the prefixing unit 14, 15 ensures that the film wrapping formed with the aid of the film 3 is or remains closed on all sides and retains this generally closed property even during the shrinking process in the final fixing unit 16. That is, with the help of Vorfixiereinheit 14, 15 it is ensured that the folding tabs 5, 6, 7, 8 at the same time mutually positioned and initially prefixed by the action of heat. The entire packaging unit 2 then undergoes an end fixation in the final fixing unit 16 again by the action of heat.

It can be seen that the pre-fixing unit 14, 15 adjoins the folding unit 9. This can be done directly, that is without the interposition of any further elements or units. In addition, the design is regularly made such that the end fixing unit 16 follows the pre-fixing unit 14, 15. In this case, too, it has proven useful if the final fixing unit 16 directly adjoins the pre-fixing unit 14, 15, that is to say without intervening further units or elements.

In the context of the embodiment of the Fig. 3 and 4A to 4D Different variants of the pre-fixing unit 14, 15 are followed. In fact, the pre-fixing unit 14, 15 may be equipped with a longitudinally fixed heat source 15, as shown in FIGS Fig. 4A . 4B . 4C and 4D i is shown, which, however, do not belong to the invention. Basically, however, the heat source 15 can be moved with the packaging unit 2 during its movement in the direction L on the transport path T, as shown in the Fig. 3 indicated by an arrow.

In any case, the prefixing unit 14, 15 has on the one hand the already mentioned heat source 15 and on the other hand a pressure element 14. Mostly, the heat source 15 and the pressure element 14 are designed separately from each other. But it is also possible that the pressure element 14 and the heat source 15 form a structural unit 14, 15, as shown in the Fig. 4D is shown.

With the aid of the pressing element 14, the folding tabs 5, 6, 7, 8 previously applied by resorting to the folding unit 9 to the packaging unit 2 are held in this position in contact with the packaging unit 2 as it passes through the prefixing unit 14, 15. In this way, the pre-fixing unit 14,15 acts on the folding tabs 5, 6, 7, 8 at the same time mechanically and with heat. There are various ways of supplying energy to the heat source 15 as part of the Vorfixiereinheit 14, 15. In the illustrated examples according to the Fig. 3 and 4A to 4C is the heat source 15 as part of the Vorfixiereinheit 14, 15 designed to be self-sufficient, that is independent of the heat source in the Endfixiereinheit or the shrink tunnel 16th

As part of the variant after the Fig. 4D However, the heat source 15 is completely or partially powered by the Endfixiereinheit or the shrink tunnel 16 energetically. For this purpose, the design is such that the heat source 15 of the Vorfixiereinheit 14, 15 extends into the final fixing unit 16 or rich, as shown in Fig. 4D is shown.

Actually, the heat source 15 according to the embodiment is according to the Fig. 4D by a guide or two fixed guides 14, which extend into the shrink tunnel 16 and at the same time act as a pressing element 14. In this way, the guides or the heat source 15 is energetically fed by the heat source located in the shrink tunnel 16. In fact, in the shrink tunnel 16, for example, nozzles as components of the already mentioned hot air blower for acting the packaging unit 2 be realized with hot air, at the same time the questionable guides 14 and the heat source 15 in the context of the variant of the Fig. 4D apply.

Basically, the prefixing unit 14, 15 ensures that the folding tabs 5, 6, 7, 8 are mechanically loaded by means of the pressing element 14. Additionally or alternatively, it is also possible that the folding tabs 5, 6, 7, 8 are mechanically mutually positioned and aligned by an air flow. This is in the embodiment according to the Fig. 4B the case. Here, the pressing element 14 is designed as a circulating chain. The chain runs around the fixed heat source 15 around. In this way, the heat source 15 is able to act on the folding tabs 5, 6, 7, 8 by correspondingly hot air flows in the manner described or to ensure that the folding tabs 5, 6, 7, 8 during the passage by the Vorfixiereinheit 14, 15 remain in contact with the packaging unit 2. The suggest appropriate arrows in the Fig. 4B at. In addition, the pressure element 14 or the chain provided at this point provides for the desired system.

Also in the variant Fig. 4A a stationary heat source 15 is provided, which in this case acts on a circulating belt 14 as a pressing member 14 with heat. In this way, the band 14 as such is heated and releases the heat for laminating the folding tabs 5, 6, 7, 8 thereto. At the same time, the band or the pressing element 14 in this context ensures that the folding tabs 5, 6, 7, 8 remain in contact with the packaging unit 2 when passing through the prefixing unit 14, 15. For this purpose, it may be the tape or the pressing member 14 in this case to a Teflon tape. This becomes regular - like the chain under the variant after the Fig. 4B - Moved at the same speed as the packaging unit 2 in the direction L along the Tramsportstrecke T.

In the finally to be discussed variant according to the representation in the Fig. 4C Various heating nozzles are realized, which are designed to be stationary in total and form the local heat source 15. In addition, a guide 14 is provided below the heating nozzles or the heat source 15, by means of which the folding tabs 5, 6, 7, 8 are held and positioned in contact with the packaging unit 2 as it passes through the prefixing unit 14, 15. The heating nozzles or the heat source 15 in this context ensures that the folding tabs 5, 6, 7, 8 are directly laminated or subjected to heat.

An improvement in terms of the heating nozzles consists in the use of high-energy radiators, such as. Infrared radiators. These allow a very well-defined exposure zone, possibly by suitable shielding, which is technically difficult to solve in a heating gas. The use of emitters, in particular IR emitters, is of course advantageous for the other variants.

The individual pressing elements 14 are generally equipped with a coating on at least their side facing the folding tabs 5, 6, 7, 8. The same applies to the heat source 15, provided that it comes into contact with the folding tabs 5, 6, 7, 8. This coating may be a Teflon coating, which avoids buildup caused by lamination during the passage of the folding tabs 5, 6, 7, 8. As a result, the transport process of the packaging unit 2 in the running direction L along the transport path T is not hindered.

The abovementioned embodiments can be combined with regard to their elements. For example, the heating by means of an infrared radiator or hot air of a circulating heating band can of course be provided in addition, if a part of the heating energy is obtained from the connected shrink tunnel. As mentioned above, the use of emitters, in particular IR emitters, is generally advantageous for all of the aforementioned design variants, since this requires only a very small installation space and no drive unit is required as for a heating gas and unwanted gas movements are avoided.

Claims (12)

1. Method for packaging groups of articles (1) which are combined to form packaging units (2), comprising the following steps:

   1.1) sheathing the respective packaging unit (2) in its running direction (L) on a transporting path (T) with a film (3), with the simultaneous formation of a film cover (4) and of folding flaps (5, 6, 7, 8) which in each case project beyond the packaging unit (2) along transverse peripheries;

   1.2) positioning the folding flaps (5, 6, 7, 8) against the packaging unit (2) while running through a folding unit (9), and, subsequently and/or at the same time, fixing of the folding flaps (5, 6, 7, 8) in relation to one another, with the formation of a film wrapper which is closed on all sides;

   characterised in that

   1.3) the vertically aligned folding flaps (5, 6, 7, 8) are positioned in relation to one another and, at the same time, are preliminarily fixed by the effect of heat, with the aid of a heat source (15) which extends longitudinally and moves with the packaging unit (2) during its movement in the running direction (L) of the transporting path (T), and subsequently the packaging unit (2) as a whole is finally fixed by the effect of heat, wherein the folding flaps (5, 6, 7, 8) are at least partially laminated in the course of the preliminary fixing.
2. Method according to claim 1, characterised in that the folding flaps (5, 6, 7, 8) are then preliminarily fixed to the folding unit (9) and before the transfer of the packaging unit (2) into an end fixing unit (16).
3. Method according to claim 1 or 2, characterised in that the folding flaps (5, 6, 7, 8) are preliminarily fixed with the aid of a pressing element (14), in particular laminated.
4. Method according to claim 3, characterised in that the heat source (15) and/or the pressing element (14) are arranged on both sides and parallel to the main transport direction of the packaging units (2).
5. Device for the packaging of groups of articles (1) which are combined to form packaging units (2), in particular for carrying out the method in accordance with any of claims 1 to 4,
   with

   a sheathing unit for sheathing the respective packaging unit (2) on a transporting path (T) in the running direction (L) with a film (3), and for the simultaneous formation of a film cover (4) and of folding flaps (5, 6, 7, 8) which in each case project beyond the packaging unit (2) along transverse peripheries, and also with

   a folding unit (9) for positioning the folding flaps (5, 6, 7, 8) against the packaging unit (2) while running through, and with

   a fixing device (14, 15; 16) for the at least opposing fixing of the folding flaps (5, 6, 7, 8) beneath one another, wherein

   the fixing device (14, 15; 16) is composed of a preliminary fixing unit (14, 15) for the opposing preliminary fixing of the folding flaps (5, 6, 7, 8) by the effect of heat, and

   an end fixing unit (16) for the end fixing of the entire packaging unit (2) by the effect of heat,

   characterised in that

   the preliminary fixing unit (14, 15) connects to the folding unit (9), and the end fixing unit (16) follows the preliminary fixing unit (14, 15), and wherein the preliminary fixing unit (14, 15) is equipped with a longitudinally extending heat source (15) which moves together with it.
6. Device according to claim 5, characterised in that the heat source (15) is fed with energy in whole or in part from the end fixing unit (16).
7. Device according to claim 5 or 6, characterised in that the heat source (15) of the preliminary fixing unit (14, 15) extends as far as into the end fixing unit (16).
8. Device according to any one of claims 5 to 7, characterised in that the preliminary fixing unit (14, 15) applies to the folding flaps (5, 6, 7, 8) simultaneously both mechanical force and heat.
9. Device according to any one of claims 5 to 8, characterised in that the preliminary fixing unit (14, 15) applies to the folding flaps (5, 6, 7, 8) mechanical force, with the aid at least of a pressing element (14) and/or by means of an air flow, for the mutual positioning and alignment in relation to the packaging unit (2).
10. Device according to claim 9, characterised in that the pressing element (14) and/or the heat source (15) are provided on their side facing the folding flaps (5, 6, 7, 8) with a coating, which avoids adherence.
11. Device according to any one of claims 5 to 10, characterised in that end fixing unit (16) is configured as a shrinkage tunnel (16).
12. Device according to any one of claims 5 to 11, characterised in that the folding unit (9), the preliminary fixing unit (14, 15), and the end fixing unit (16) connect immediately and directly to one another in the running direction (L).

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