EP1147050B1 - Device for shrinking a shrink-wrap film - Google Patents

Abstract

The invention relates to a device for shrinking a shrink-wrap film wrapped around a notably palletized stack of goods. To further develop such a device in such a way that the shrinkage of the upper and/or lower excess film is improved and optimal crease-free shrinkage is obtained, the invention provides for a device for shrinking a shrink-wrap film (26) wrapped around a notably palletized stack of goods (12), which device comprises at least one shrinking device (3) which can be moved up and down along a frame (2) and is designed to heat and shrink the shrink-wrap film in the vertical direction. The shrink-wrap film protrudes over the upper and/or lower edges of the stack of goods such that an upper and lower shrinkage can be formed. The device provided for in the invention also comprises at least one nozzle (19) which can be connected to a compressed gas source, notably a compressed air source, and is positioned approximately centrally above and/or below the stack of goods. Each nozzle has discharge holes (21) which are situated at an angle to the direction of flow inside the nozzle and are arranged in a substantially circular manner.

Description

The invention relates to a device for shrinking one wrapped around a stack of goods, especially palletized Heat shrink film.

Such heat shrink films are used today to i.a. Goods for example on a pallet for the Secure transportation. For this purpose, a Heat shrink wrap so that the heat shrink wrap does not slide down. This is done either directly in a shrinking station or in one of the shrinking stations upstream separate station.

The heat shrink film is then in the shrinking station supplied with hot gas by the shrinking device, so that the heat shrink film heats up to shrink temperature and shrinking around the stack of goods contracts. The shrinking device is vertical movable up and down, the shrinkage both from above down as well as from the bottom up is possible. While of the shrinkage is partially due to the stack of goods air inflated above.

From US 4,616,471 A is a device for shrinking a hood-shaped one surrounding a palletized stack of goods Heat shrink film known to consist of at least one a shrinking device that can be moved up and down for heating and shrinking the heat shrink film in vertical direction, the heat shrink film protrudes over the bottom edge of the stack of goods.

A disadvantage is that with such a device no wrinkle-free shrinkage, especially upper shrinkage, d. H. a shrinking of the top over the Stack of protruding material protruding from the heat shrink film is possible, and so for example on the top of the stack of goods between the stack of goods and the heat shrink film arranged accompanying note, for example has a barcode that is not readable.

The object of the invention is therefore to provide one mentioned at the beginning Develop the device so that the shrinkage of the top and / or bottom film overhang improved and an optimal wrinkle-free shrink achieved becomes.

This object is achieved by a device for Shrinking a stack of goods, especially palletized placed heat shrink film consisting of at least one can be moved up and down on a frame Shrinking device for heating and shrinking the Heat shrink film in the vertical direction, the heat shrink film over the top and / or bottom edge of the stack of goods protrudes to form upper and lower shrinkage, and wherein the device further consists of at least one each a gas pressure source, in particular a compressed air source Nozzle that is approximately in the middle above and / or below the Good stack arranged and on this essentially is (are) oriented vertically, with each nozzle Has outlet openings that are not in a with the Flow direction aligned angle to the flow direction aligned within the nozzle and essentially are arranged in a ring.

Due to the angle to the flow direction within the The nozzle-oriented outlet openings will be the compressed air not blown perpendicular to the surface of the stack of goods. Rather, the compressed air is either at an angle to the Surface guided and there in the direction of the film overhang deflected or - if the outlet openings approximately at a 90 ° angle to the direction of flow within the nozzle are blown directly onto the film overhang. As a result, the film overhang during the Upper shrink phase held up so that an even Heating by the shrinking device during the upper shrinking phase is guaranteed. Through this even Heating results in a wrinkle-free top shrink Pinch the excess film on top of the The stack.

Each nozzle advantageously has a chamfer at the end on, in which the outlet openings are provided, so that the compressed air at this angle in all directions is directed. The outlet openings can in Essentially at an angle of 45 ° to the flow direction inside be aligned with the nozzle.

So that stacks of different dimensions in the Shrinking station shrunk with a heat shrink film can be moved, each nozzle can be moved up and down. This allows the ideal distance for the upper shrink phase between the nozzle and the stack according to the height the stack of goods and / or the dimensions of the top of the Good stacks can be set.

To avoid the not shrunk heat shrink film slides down, is still provided that the device for holding the heat shrink film has a pressing device on the stack of goods, preferably on one for lifting the stack of goods provided lifting table is attached.

Fig. 1

eine Seitenansicht auf eine erfindungsgemäße Vorrichtung,

Fig. 2

eine Durchsicht durch den Ausblasbereich einer Düse und

Fig. 3

einen Schnitt durch den Gegenstand nach Fig. 2.

An exemplary embodiment illustrated in the drawings is explained below. Show it:

Fig. 1

a side view of a device according to the invention,

Fig. 2

a view through the outlet area of a nozzle and

Fig. 3

a section through the object of FIG. 2nd

In the figures, the same or similar parts uses the same reference numerals.

Fig. 1 shows a shrinking station 1, which consists of a frame 2 and a shrinking device 3, for. B. in the form of a Ring burner exists.

The frame 2 has two in a plane perpendicular to Masts 4 arranged next to each other on the drawing level, of which only the front one can be seen in this view is. Both masts 4 are connected via a connecting their upper ends, not shown cross yoke connected to each other.

A drive 5 is guided vertically movable on each mast 4, the leadership is done via rollers 6, 7. The vertical movement of the drive 5 is rotating Chain 8 causes the deflection on the lower and the upper end of the mast 4 via appropriate sprockets 9, 10 takes place.

The chain 8 is driven by a in the lower area the masts 4 arranged drive motor 11, wherein both drives 5 are synchronized with one another in such a way that they are always at the same level.

The drives 5 are by the shrinking device 3rd interconnected, one corresponding to the cross-sectional area of a stack of goods 12 adapted shape - In the case shown, an angular, frame-like Shaping - having, by the shrinking device 3 enclosed area is large enough for this can be moved vertically over a stack of goods 12.

Such a stack of goods 12 is located below the Shrinking device 3 on a conveyor 13, for example as a chain, roller or truss conveyor can be trained. The stack of goods 12 exists thereby from a usual pallet 14 and the stacked thereon Good 15. If goods of 15 large dimensions are packed a pallet 14 is not absolutely necessary.

A lifting platform is located below the stack of goods 12 or a lifting table 16, on the top of which a lifting ram 17 through a corresponding gap in the conveyor upwards between the not shown base strips of the pallet 14 protrudes. In the area of the jack 17 and below the Conveyor 13, a suction fan can be arranged.

There is a nozzle above and below the stack of goods 12 19 provided, which can also be removed and stored can. Each nozzle 19 is - as can be seen from FIG. 2 - at the end blunt and has a circumferential bevel 20 on that at an angle of about 45 ° to the flow direction is arranged within the nozzle 19. In this Chamfer 20, outlet openings 21 are arranged so that the Compressed air passed obliquely to the stack of goods 12 (arrows 22) becomes. As shown in Fig. 3, the exit openings go 21 star-shaped from one centered in the nozzle 19 arranged supply channel 23 from.

When hitting the top of the stack of goods 12 the compressed air is deflected and caused in the direction of arrows 24 erecting and thus holding up a film overhang 25 a heat shrink film 26. Furthermore the compressed air emerging via the nozzle 19 guides the hot air the shrinking device 3 to the inside of the film overhang 25. The shrinking device 3 is via supply lines 27 supplied with gas.

If only one nozzle 19 - as shown - for The top and bottom shrink is used for the outlet openings 21 in a ring around the circumference of the chamfer 20 - As shown in Fig. 3 - distributed, so that Compressed air is directed in all directions. If however, several nozzles 19 are provided, the outlet openings 21 of each nozzle 19 preferably so arranged that each nozzle 19 only the compressed air guides a certain area of the stack of goods 12; however is the arrangement of the outlet openings 21 under the intended Nozzles 19 selected so that the film protrusion 25 of the heat shrink film 26 at every point through the Compressed air is erected.

Shrinking with the device according to the invention is possible as follows.

First, the heat shrink film 26 is placed around the stack of goods 12 laid or wrapped. This can be done in a the shrinking station 1 upstream station or in the Shrinking station 1 itself. Provided that moving in a separate station, the one with the Heat shrink film 26 surrounding material stack 12 by means of the Conveyor 13 transported to the shrinking station 1.

Both sides of the conveyor 13 are usually to be put on the heat shrink film 26 arranged vertical film rolls, each of which the heat shrink film 26 rolled becomes. The two ends of the unwound from the film rolls Heat shrink films 26 end together welded. When passing the film rolls the stack of goods 12 from the heat-shrink films welded together 26 surrounded, the two heat shrink films 26 provided with a double weld seam on the back become.

Subsequently, the Heat shrink film 26 in the middle between the two weld seams severed so that the next stack of goods 12 with a heat shrink film 26 can be provided. The heat shrink film If possible, 26 is due to that Good stack 12 that they do not slide down can. It is obvious that the stack of goods 12 too provided with the heat shrink film 26 in another way can be. In the event that the heat shrink film 26 is not tight enough against the stack of goods 12 is on the lifting table 16 is provided with a pressing device 28 which presses the heat shrink film onto the stack of goods 12 and thus holds.

In the shrinking station 1 takes place subsequently by vertical Method of shrinking device 3 the shrinking the heat shrink film 26 instead. It makes sense that shrinking occurs from top to bottom, however shrinking in the opposite direction is also possible.

To achieve good top shrink, i. H. to the Shrinkage of the excess film protruding from the stack of goods 12 25, 19 is compressed air on the nozzle Blown surface of the stack of goods 12. The compressed air strikes the stack of goods 12 (arrows 22) at an angle and is deflected by this in the direction of arrows 24. hereby the film overhang 25 to the outside and upwards pressed so that this during the top shrink phase is erected and therefore evenly by the hot gas the shrinking device 3 is heated.

As soon as the film supernatant 25 is heated to shrink temperature the compressed air supply via the nozzle 19 is switched off, so that the film overhang 25 over the Surface of the stack of goods 12 pulls.

Subsequently, the shrinking device 3 to Shrinking the side surfaces of the stack of goods 12 downwards process, the heat shrink film 26 over the Side surfaces of the stack of goods 12 pulls together strongly.

If additional shrinkage is desired is, d. H. the bottom of the heat shrink wrap 26 comprises the stack of goods 12 or the pallet 14, the Good stack 12 through the lifting ram 17 by means of the lifting device 16 slightly raised.

Then the shrinking device 3 up to the level of the conveyor 13 by the corresponding method of Drives 5 lowered.

Now the lower edge of the heat shrink film 26 is through the shrinking device 3 is charged with hot gas, so that it heats up to shrink temperature and contracts under the bottom of the pallet 14. to Achieving good shrinkage also serves at least a nozzle 19.

Then the stack of goods 12 with the edge still heated the heat shrink film 26 is lowered again onto the conveyor 13, whereby the hot edge between the conveyor 13 and the bottom of the pallet 14 pressed together with the effect is that a welding of the individual layers this edge takes place. This gives the lower one Edge of the heat shrink film 26 an extremely good hold.

After the shrinking process has been completed, the stack of goods 12 moved out of the shrinking station 1 via the conveyor 13 become. Repeats for a new stack of goods the procedure described above.

Claims (6)

1. Apparatus for shrinking a heat-shrinkable film (26) placed around a stack of goods (12), more especially a palletised stack of goods, said apparatus comprising at least one shrinking device (3), which is upwardly and downwardly displaceable on a frame (2), in order to heat and shrink the heat-shrinkable film (26) in the vertical direction, the heat-shrinkable film (26) protruding beyond the upper edge and/or lower edge of the stack of goods (12) to produce upper and/or lower shrink-wrapping, characterised in that the apparatus also comprises at least one respective nozzle (19), which can communicate with a gas pressure source, more especially a source of compressed air, which nozzle or nozzles is or are disposed approximately centrally above and/or below the stack of goods (12) and orientated so as to point substantially vertically towards said stack, each nozzle (19) having outlet apertures (21) which are orientated at an angle relative to the direction of flow within the nozzle (19), which angle is not in alignment with the direction of flow, and said apertures are disposed substantially annularly.
2. Apparatus according to claim 1, characterised in that each nozzle (19) has, at its end, a chamfer (20) in which outlet apertures (21) are provided.
3. Apparatus according to claim 1 or 2, characterised in that the outlet apertures (21) are orientated substantially at an angle of 45° relative to the nozzle (19).
4. Apparatus according to one of claims 1 to 3, characterised in that each nozzle (19) is upwardly and downwardly displaceable.
5. Apparatus according to one of claims 1 to 4, characterised in that a pressure applicator (28) is provided to secure the heat-shrinkable film (26) on the stack of goods (12) during the shrinking operation, more especially the upper shrink-wrapping operation.
6. Apparatus according to claim 5, characterised in that the pressure applicator (28) is attached to a lift platform (16) for the stack of goods (12).

Images