EP2347960B1 - Shrink tunnel - Google Patents

Abstract

The tunnel (10) has a transportation path (8) for an article (22), where the article is supplied with shrinking medium i.e. warm air (30), via a folding-shaft wall (12). Outer shafts (40) and a shaft are arranged parallel to each other. The shaft is arranged at inner side (11) of the tunnel and swiveled out at an axis on the transport path. The shaft includes lower and upper portions, which are movable against each other such that height of the shaft is reduced. A folding mechanism is arranged between the portions of the shaft, where the lower portion is folded in an upward direction. An independent claim is also included for a method for converting a shrink tunnel.

Description

The present invention relates to a shrink tunnel. The shrink tunnel has formed at least one transport route for articles. Two outer shafts and at least one shaft inside the shrink tunnel form the different transport routes. The articles can be acted upon by a shrinkage medium, wherein the at least three shafts are arranged parallel to each other.

Furthermore, the invention relates to a method for converting a shrink tunnel.

The prior art discloses methods and devices for packaging articles (packaged goods) which use a shrink film as the packaging wrapper for the articles. This shrink film is usually provided as a continuous material on rolls.

The shrink film is separated within the packaging device according to the container dimensions. The foil blanks are then wrapped around the articles by means of a wrapping system within the device. The containers are then transported through a shrink tunnel. In the shrink tunnel, the wrapped articles are heated with hot gas, e.g. warm or hot air acted as shrinking medium, whereby the shrink film contracts, so that it conforms to the article and the finished shrink packaging arise.

Often, the packages, depending on their size, fed to the shrink tunnel in several parallel paths and processed in this. To be able to apply warm air to all packages from all sides, means for introducing the warm air must also be provided, which inject the shrinkage medium between the articles guided in parallel. For example, shrink tunnels with movable shaft walls are used for the multi-lane processing. In this case, the shaft walls are driven as required by costly spindle adjustments to the side tunnel wall, if they are not needed. Such an arrangement is in FIG. 1 shown. In particular, one is Shrink tunnel 100 shown in the interior 102 movable shaft walls 110 are arranged. The example shows a double-row processing of containers 20 in such a shrink tunnel 100. The containers 20 consist of articles 22, which are enveloped by a shrink film 24. In the illustrated shrink tunnel 100, the containers 20 are supplied with the warm air 30 via nozzles in the shaft walls 110 by means of three movable shaft walls 110 ( Figure 1 A) , If in the shrink tunnel 100 only in a row arriving containers 20 are processed ( FIG. 1C) , then the shaft walls 110, as in FIG. 1B shown to be moved in a horizontal direction of movement BR.

US 3,711,957 shows a shrink tunnel with a single-lane processing, wherein on the opposite sides of the tunnel in the transport direction in each case a hot air blower is arranged.

US 5,339,605 describes a shrink tunnel with a product press in which first the side-mounted shrink film is subjected to the shrinking process and only then the shrink wrap on the top and bottom of the heat is exposed and shrunk. The use of a second, above the first arranged conveyor as a product press in conjunction with a two-stage shrinkage process, an expansion of the product to be packaged is prevented.

WO 2002/036436 describes the multi-lane processing of containers in a shrink tunnel. In this case, movable shaft walls are used whose position is adjusted depending on the containers to be processed by lateral displacement in the horizontal direction.

The object of the invention is to provide a shrink tunnel in which a single or multi-lane processing can be carried out, wherein the switching between single or multi-lane processing is fast, easy and tool-free.

The above object is achieved by a device comprising the features of claim 1.

It is another object of the invention, a method for converting a To provide shrink tunnels in which a single or multi-lane processing can take place.

The above object is achieved by a method comprising the features of claim 7.

The present invention relates to a shrink tunnel, in particular a shrink tunnel for heat shrinking of film by article, for example, to create containers from several containers, which are covered with a shrink film. Furthermore, the shrink tunnel can also serve to shrink labels or the like. to apply to the articles by shrinking.

The shrink tunnel comprises at least one transport route for the articles. The shrink tunnel has two shafts bounding the tunnel outwards and at least one shaft arranged in the interior of the shrink tunnel. The shafts can be acted upon by a shrinking medium and lead this through nozzles in their shaft walls in the interior of the shrink tunnel. Preferably, the shrinkage medium is a warm or hot air stream.

The at least three shafts, i. the two outer shafts and the at least one arranged inside the shrink tunnel shaft can be arranged parallel to each other.

According to the invention, the at least one shaft arranged in the interior of the shrinking tunnel can be swiveled out of the transport path by at least one axis. Preferably, the shaft is pivoted substantially 90 ° upwards.

According to a preferred embodiment, the two outer shafts each have a shaft wall with a plurality of directed into the interior of the shrink tunnel on the articles nozzles. By contrast, the at least one shaft arranged in the interior of the shrinking tunnel has two shaft walls arranged in parallel, each with a plurality of nozzles.

The at least one inner shaft is in the folded-down state, so that it the transport route in at least two transport tracks is diverted from this shaft of shrinkage medium in two opposite directions in the two inner portions of the shrink tunnel.

According to a preferred embodiment, the at least one shaft arranged in the interior of the shrink tunnel is not constantly subjected to shrinkage medium. Instead, the supply of shrinkage medium is switched on and off and preferably depends on the position of the shaft. If the inner shaft is arranged parallel to the outer shafts, so that a subdivision of the transport path into at least two transport paths and at least two inner portions of the shrink tunnel, then the supply of shrinking medium is preferably switched on, so that through the nozzles of the shaft walls of the inner shaft Shrinking medium is passed into the two inner portions of the shrink tunnel. If, on the other hand, the inner shaft has been swung out of the transport path, the feed can be switched off by the shrinking medium.

According to an alternative embodiment, the switching on and off of the shrinking medium to the at least one inner shaft is automated depending on its position. The advantage, if the inner shaft is not constantly acted upon by shrinking medium, in the case of the use of hot or hot air, in particular in the saving of energy, since not unnecessarily air must be heated. In the case of using another shrinking medium, the advantage in particular in the adapted, reduced consumption of the corresponding medium.

According to a further embodiment of the invention, the inner shaft consists of a first and a second section which are movable relative to each other such that the height of the shaft can be reduced. Preferably, the height of the shaft can be reduced to about 50%. For example, a folding mechanism can be arranged between the first and the second section, which extends over the entire width of the central shaft and is arranged substantially centrally with respect to the height of the shaft. Preferably, the lower portion is hinged upwardly about this folding mechanism, so that the lower and the upper portion can be arranged in parallel side by side. Furthermore, fasteners may be provided, which folded up the bottom Securely fix the section in this position. For example, latching elements could be provided which engage in corresponding receptacles of the respective other section.

According to an alternative embodiment, the lower portion and the upper portion are mutually displaceable, so that the lower portion can be moved upwards and thus the overall height of the shaft can be reduced again. Again, corresponding fixing elements may be provided.

In a further embodiment, a linkage with two pivot joints may be provided above the shaft wall, wherein the linkage is rotatably connected to the shaft wall at one of the pivot joints. To swing out the shaft wall from the transport section, two pivoting movements are performed. On the one hand, the linkage pivots about a first axis out of the transport path. Furthermore, the shaft wall pivots about a second axis. Preferably, the pivotal movement about the first pivot opposite to the pivotal movement about the second pivot. The axis of rotation can be arranged centrally or eccentrically to the symmetry line of the shaft wall.

In still another embodiment, the shaft wall is first pushed up along a linkage and then pivoted upwardly about an axis D. The space required for pivoting inside the shrink tunnel is thus lower. However, the height of the containers to be processed is limited upwards by the offset axis D.

The invention further relates to a method of retrofitting a shrink tunnel from a first number of webs to process articles to a second number of webs. First, the desired second number of tracks to be processed is input to a control unit. The control unit determines by comparing the known first number of tracks with the desired second number of tracks whether a division by more or fewer slots is needed. On the basis of the determined information, the at least one shaft arranged inside the shrinking tunnel is folded up when the second number of transport tracks is smaller than the first number.

If, however, the second number of transport paths is greater than the first Number, then the at least one arranged in the interior of the shrink tunnel shaft is folded down.

This process can take place automatically, or else be performed manually by an operator.

According to a preferred embodiment, the supply from the shrinkage medium to the inner shrinkage medium is controlled in dependence on the position of the shaft. In particular, the supply is activated when the inner shaft is arranged parallel to the two outer shafts and deactivated when it is pivoted out of the transport path.

In summary, the invention relates to the use of at least one, by about 90 ° upwardly pivotable "folding shaft wall". As a result, a shrink tunnel can be offered at relatively low cost, which can be easily converted when using an inner shaft between a single-lane and a two-lane processing.

The pivotable shaft wall is mechanically simple to implement and much less expensive than the known from the prior art movable shafts.

• Figur 1 zeigt einen Schrumpftunnel mit verfahrbaren Schachtwänden (Stand der Technik).
• Figur 2 zeigt ein erstes Ausführungsbeispiel einer erfindungsgemäßen Verstellung von Schachtwänden.
• Figur 3 zeigt ein zweites Ausführungsbeispiel einer erfindungsgemäßen Verstellung von Schachtwänden.
• Figur 4 zeigt ein drittes Ausführungsbeispiel einer erfindungsgemäßen Verstellung von Schachtwänden.
• Figur 5 zeigt ein viertes Ausführungsbeispiel einer erfindungsgemäßen Verstellung von Schachtwänden.
• Figur 6 zeigt ein fünftes Ausführungsbeispiel einer erfindungsgemäßen Verstellung von Schachtwänden.
• Figur 7 zeigt ein sechstes Ausführungsbeispiel einer erfindungsgemäßen Verstellung von Schachtwänden.

In the following, embodiments of the invention and their advantages with reference to the accompanying figures will be explained in more detail. The proportions of the individual elements to one another in the figures do not always correspond to the actual size ratios, since some shapes are simplified and other shapes are shown enlarged in relation to other elements for better illustration.

• FIG. 1 shows a shrink tunnel with movable shaft walls (prior art).
• FIG. 2 shows a first embodiment of an adjustment of shaft walls according to the invention.
• FIG. 3 shows a second embodiment of an inventive adjustment of shaft walls.
• FIG. 4 shows a third embodiment of an inventive adjustment of shaft walls.
• FIG. 5 shows a fourth embodiment of an inventive adjustment of shaft walls.
• FIG. 6 shows a fifth embodiment of an adjustment of shaft walls according to the invention.
• FIG. 7 shows a sixth embodiment of an inventive adjustment of shaft walls.

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments are only examples of how the device according to the invention can be designed and do not represent a final limitation.

FIG. 1 has already been described in the prior art.

FIG. 2 1 shows an embodiment of a shrink tunnel 10 with an adjustment according to the invention of a shaft wall 12.

The heat-shrinkable medium, in particular hot air 30, to be acted upon by shrink-wrap film 24 to form bundles 20 are transported along a transport path 8 through the shrink tunnel 10.

In the embodiment shown, there is a change from a two-lane to a single-lane processing of containers 20. In this case, a folding shaft wall 12, which can be pivoted up to a maximum of 90 °, is used.

The folding shaft wall 12 is associated with at least one hot air generator, which generates the warm air 30, which is passed to the production of containers 20 through nozzles 44 in the interior 11 of the shrinking tunnel 10 on the covered with shrink film 24 Article 22.

The shaft wall 12 is formed pivotable about an axis D. The Shaft wall 12 is arranged such that it can be folded up as required, ie when, for example, it is intended to switch from a two-lane to a single-lane processing, and thus comes from the transport path 8.

By pivoting down the shaft wall 12 about the axis D is a subdivision of the transport path 8 in two transport paths ( FIG. 2A ), so that a two-lane processing is possible. If the shaft wall 12, however, swung up ( Figure 2B, 2C ), then the transport path 8 corresponds to a transport path.

If the shaft wall 12 is in the folded-up state, then the supply of warm air is preferably switched off. For example, the hot air generator (not shown) assigned to this shaft wall 12 is switched off or the hot air supply to the shaft wall is interrupted.

Another embodiment is in FIG. 3 shown. In the shaft wall 12 shown here, the axis D is not offset at the upper end of the shaft wall 12 but slightly offset downwards. In this embodiment, the space required for pivoting in the direction of movement BR lateral space in the interior 11 of the shrink tunnel 10 is thus lower. However, the height of the containers 20 to be processed 20 is limited by the offset axis D upwards. It is thus possible to reduce the width of the shrinking tunnel, where appropriate, the above-mentioned disadvantage must be taken into account.

Another space saving embodiment is in FIG. 4 shown. The shaft wall 12 has, for example, a hinge 16 which divides the shaft wall 12 into an upper part 12a and a lower part 12b ( FIG. 4A ).

First, the shaft wall 12 is folded by folding the lower part 12b upwards around a hinge 16 (FIG. FIG. 4B, FIG. 4C ). In particular, devices may be provided on the upper part 12a, in which engage corresponding devices arranged on the lower part 12b and thus produce a detachable connection between the two parts 12a, 12b of the shaft wall 12. This prevents that the folded-up lower part 12b automatically folds down again.

According to another embodiment, not shown, the lower part 12b can be folded up with another simple lever mechanism. This solution is used when the width of the shrink tunnel interior is not sufficient to stow the shaft wall by folding only one axis. In this case, it turns around, several axes.

Subsequently, the folded shaft wall 12 is pivoted about the axis D upwards. It is also conceivable in a further embodiment that the two parts 12a and 12b of the shaft wall 12 are pushed into one another in order to reduce the height H of the shaft wall 12.

A fourth and a fifth possible embodiment are in the Figures 5 and 6 shown. Above the shaft wall 12 shown here, a linkage 18 with two hinges 19a, 19b is arranged. The linkage 18 is rotatably connected to the shaft wall 12 at the lower hinge 19b. To swing out the shaft wall 12 out of the transport path 8, two pivoting movements are performed ( FIG. 5B . FIG. 6B ). On the one hand, the linkage 18 pivots out of the transport path 8 in the direction of movement (a) about the axis D1 of the upper pivot joint 19a. Furthermore, the shaft wall 12 pivots about the axis D2 in the direction of movement (b) about the lower hinge 19b upwards. Preferably, the pivotal movement about the upper hinge 19a is opposite to the pivotal movement about the lower hinge 19b. The axis of rotation D2 can center ( FIGS. 5A to 5C ) or eccentric to the symmetry line S of the shaft wall ( FIGS. 6A to 6C ) can be arranged.

In these embodiments, the lateral space required for pivoting in the interior 11 of the shrink tunnel 10 is thus less than that in FIG FIG. 2 shown first embodiment.

Also FIG. 7 shows a space-saving possibility of clearing a shaft wall 12. Here, the shaft wall 12 is first pushed along a linkage 17 upwards ( FIG. 7B ) and then pivoted upwards about an axis D ( FIG. 7C ). In this embodiment, the axis D is again arranged offset downwards (that is similar to that in FIG Figure 3 shown second embodiment). The space required for pivoting inside 11 the shrink tunnel 10 is thus lower. However, the height of the containers 20 to be processed 20 is limited by the offset axis D upwards.

With the in the FIGS. 2 to 7 described embodiments of a shrink tunnel 10 is a very space-saving clearing "of the shaft walls 12 and a switch from two- or multi-lane processing to single-lane processing or processing in fewer lanes easy and inexpensive possible.

The invention has been described with reference to a preferred embodiment. However, it will be apparent to those skilled in the art that modifications or changes may be made to the invention without departing from the scope of the following claims.

In particular, the invention may serve to create packages of shrink wrapped articles. Furthermore, the shrink tunnel according to the invention can also serve other applications, such as the application of shrink labels on items, such as bottles or similar.

LIST OF REFERENCE NUMBERS

8th

transport distance

10

shrink tunnel

11

Heart of the shrink tunnel

12

Folding shaft wall

12a

Upper part of the hinged shaft wall

12b

lower part of the hinged shaft wall

16

Hinge / hinge

17

linkage

18

linkage

19a

Upper swivel joint

19b

lower hinge

20

container

22

items

24

shrink film

30

warm air

40

outer shafts

42

shaft wall

44

jet

100

shrink tunnel

102

Heart of the shrink tunnel

110

movable shaft wall

(A)

movement direction

(B)

movement direction

BR

movement direction

D

axis

H

Height of the shaft wall

Claims (8)

1. Shrink tunnel (10) comprising at least one transport route (8) for articles (22), two outer shafts (40) and at least one inner shaft (12) located in the inside (11) of the shrink tunnel (10), whereby a shrinking medium (30) can be applied onto the articles (22) by the shafts (40, 12), whereby the at least three shafts (40, 12) can be arranged parallel to each other, characterized by that the at least one inner shaft (12) that is located inside (11) the shrink tunnel (10) is pivotal about at least one axis (D) and can be swiveled out of the transport route (8).
2. Shrink tunnel according to claim 1, whereby no shrink medium (30) is applied through the inner shaft (12) located inside (11) the shrink tunnel (10), when the inner shaft (12) is swiveled out of the transport route (8).
3. Shrink tunnel according to claim 1 or 2, whereby the at least one inner shaft (12) comprises a first part and a second part (12a, 12b), whereby the first part and the second part (12a, 12b) are movable relative to each other, whereby the height of the inner shaft (12) is reducible.
4. Shrink tunnel according to claim 3 whereby a folding mechanism (16) is located between the first part and the second part (12a, 12b) of the shaft (12), whereby the lower part (12b) can be folded upwardly, so that the lower part and the upper part (12a, 12b) can be arranged parallel beside each other
5. Shrink tunnel according to claim 3 whereby the lower part (12b) and the upper part (12a) can be shifted along each other.
6. Shrink tunnel according to one of the previous claims, comprising at least one means for supplying the shrinking medium (30) into the shafts (40, 12), whereby the shafts (40, 12) each comprise at least one shaft wall (42) with a plurality of nozzles (44) directed towards the articles (22) and whereby the shrinking medium (30) is guided into the inside (11) of the shrink tunnel (10) through the nozzles (44).
7. Method for the conversion of a shrink tunnel (10), comprising at least one transport route (8) for articles (22), two outer shafts (40) and at least one inner shaft (12) located inside(11) the shrink tunnel (10), whereby shrinking medium (30) is applied onto the articles (22) by the shafts (40, 12), where by the three shafts (40, 12) can be arranged parallel to each other, characterized by the following steps:

   • entering a required second number of processing tracks into a control unit;

   • swiveling out or folding up the at least one inner shaft (12) located inside (11) the shrink tunnel (10) if the second number of processing tracks is smaller than the first number of processing tracks OR

   • unfolding the at least one inner shaft (12) located inside (11) the shrink tunnel (10) if the second number of processing tracks is bigger than the first number of processing tracks.
8. Method according to claim 7, whereby the supply of shrinking medium (30) for an inner shaft (12) located inside (11) the shrink tunnel (10) is activated, when the inner shaft (12) is arranged in parallel to the two outer shafts (40), and whereby the supply of shrinking medium (30) for an inner shaft (12) located inside (11) the shrink tunnel (10) is deactivated, when the inner shaft (12) is swiveled out of the transport route (8).

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