EP1000858B1 - Method and device for applying and shrinking a packaging hood on an object - Google Patents

Description

The invention relates to a method and an apparatus for packaging a Subject according to the preamble of claim 1 or according to the preamble of claim 13. Such a method and a corresponding device are used in particular for packing stacks of goods on a Pallet are arranged and should be transported in any form. The stack of goods is protected from the weather by the film hood and receives increased stability.

In known methods and devices for packaging objects In a first processing step, a film tube is placed in a processing room supplied in the desired length, welded to a film hood and cut off the formed film hood. Then the film hood opened and with grippers of the shrink frame over the object to be packed drawn. In order to shrink the film hood onto the object then the shrink frame, the one the object to be packed in a ring surrounding heater means from the bottom portion of the article moved up again. The heating device is switched on, see above that the film hood with the supply of heat to the object to be packaged is shrunk.

A corresponding device in which the shrink frame corresponds to the heating device to the gripping device when the film is pulled over the stack of goods is moved down is described in EP 88 424. But even with this device the heating device only starts when the film hood is completely over the entire Stack of goods is pulled. Only then will the heater with the shrink frame moved upwards, so that the shrinking takes place from bottom to top.

This method and the corresponding device are quite limited in their capacity, since the individual process steps are carried out one after the other, so that the gripping device first pull the film hood completely over the object, before the in the Shrink frame located at the bottom of the object with the shrinking process can start. Only after the shrinking process is the packaged item moved on and the next unpacked item is moved into the device. The cycle time Such a known device is therefore relatively long in relation to it the number of packaged items per unit of time makes it relatively expensive.

Furthermore, there is no particular shrink quality. Finally, there is no guarantee that the film of already shrunk goods of the packaged goods with the shrink film bonded. To prevent such sticking, pressure fans have been proposed Inflate the film hood so that it does not lie directly on the object. The control However, this blower is quite expensive and there is a risk that the film hood inflated too close to the shrink frame and consequently holes are burned into the film hood by overheating the film hood.

It is therefore an object of the present invention to provide a method and an apparatus for To pack an item that increases performance is, at the same time sticking the film hood and undesirable hole formation in the film hood and / or undesirable wrinkling in the film hood be avoided.

This object is achieved with a method according to the features of claim 1 and with a device with the features of claim 13 solved. Advantageous configurations of the invention are disclosed in the dependent claims.

According to the method according to the invention, the film hood is pulled over shrunk over the object to be packed. This will make the the two process steps of covering and shrinking combined in time, so that the cycle times of the process are shortened and the Performance is increased. Furthermore, the suction of air or there is no need to inflate the film hood while shrinking, because the shrinking takes place while the film hood is pulled over the object becomes. This also enables a particularly uniform and reliable Shrinkage of the film material, which prevents wrinkling.

In a preferred embodiment of the invention, the film hood is by means of a heating device by supplying heat above a gripping device shrunk the item. This enables an effective and consistent Shrinking process, because when shrinking the heating device in a fixed Distance to the gripping device and the film wall can be positioned.

Heat is preferably applied to the film hood before it contacts the Has created object so that the pulling of the film hood over the Object runs essentially without contact. This prevents any Damage such as cracks or the like when pulling over the film hood. Furthermore, the Shrink the film hood wrinkle-free onto the object, reducing its mechanical Properties, especially the tear strength improved.

In a preferred embodiment of the invention, the heat supply is at Shrinkage of the film hood controllable, so that objects with irregular Surfaces can be shrunk better. For irregular surfaces the distance of the film hood to the heating device changes, so that an individual adjustment of the heat supply is required for certain areas is.

According to a particularly effective method, the film hood is first applied their top side shrunk onto the object and then the heater together with a gripping device that reefs the film hood Condition holds, moved down. This results in a particularly tight fit the film hood on the object.

A further increase in performance can be achieved if the film hood is opened by a first gripping device and then to a second gripping device is passed. The second gripping device can then initiate the shrinking process together with the heater while the First gripping device pick up the subsequent film hood and put it in the reefed Can bring condition.

In a preferred embodiment, the film hood is on the underside of the object sucked inwards and at least partially on the underside of the object shrunk, so that the seat of the film hood is particularly firm becomes. For a further increase in stability, the film hood can bottom area to be welded with a bottom film. This allows also achieve sealed packaging of the item. At the cycle times To make it as short as possible, the film hood can be shrunk onto the heated one Area to be cooled. This enables a particularly large one Heat supply in a short time, since the excess heat is dissipated quickly can.

According to the device according to the invention when the film hood is pulled over over the object the heater at a fixed distance above a second movable gripping device for covering the film hood. this makes possible a simultaneous covering of the film hood and shrinking it on the object. It can also be reliable and fast Carry out shrinking because the distance between the film hood and the heating device especially for objects with irregular surfaces, relative is even. This enables wrinkle-free shrinking and deployment a resilient shrunk film hood.

In a preferred embodiment of the device according to the invention the gripping device for covering the film hood on the shrink frame connectable or connected to this. In both cases, the distance of the Gripping device to the heater on the shrink frame quickly and fix in a simple way.

Preferably can the the first gripping device has a plurality of suction boxes for opening the film hood, while the second gripping device is connected to the shrink frame can be.

According to a preferred embodiment of the invention, the shrink frame has In addition to the heating device, a cooling device with which a rapid cooling of the film hood is achieved after shrinking. This enables an intensive heat supply and a shortening of the time Shrinking process.

Is preferably between the first gripping device and the second gripping device a heat shield is provided so that the opening of the film hood can take place in a relatively sheltered cooler room and sticking the following slide can be prevented.

Fig. 1

eine schematische Ansicht einer erfindungsgemäßen Vorrichtung;

Fig. 2

eine vergrößerte Darstellung der Greifeinrichtung zum Öffnen der Folienhaube;

Fig. 3

eine vergrößerte Darstellung eines Ausschnitts der ersten Greifeinrichtung zum Öffnen der Folienhaube;

Fig. 4

eine Darstellung der erfindungsgemäßen Vorrichtung, bei der die Folienhaube in verschiedenen Verfahrenszuständen gezeigt ist;

Fig. 5

eine schematische Darstellung des Schrumpfvorgangs;

Fig. 6

eine Ansicht des fertig verpackten Gegenstands;

Fig. 7

eine ausschnittsweise Ansicht des zu verpackenden Gegenstands auf einem Hubtisch, und

Fig. 8

eine schematische Darstellung des Fördervorgangs durch die erfindungsgemäße Vorrichtung.

The invention is described below using an exemplary embodiment with reference to the accompanying drawings. Show it:

Fig. 1

a schematic view of a device according to the invention;

Fig. 2

an enlarged view of the gripping device for opening the film hood;

Fig. 3

an enlarged view of a section of the first gripping device for opening the film hood;

Fig. 4

a representation of the device according to the invention, in which the film hood is shown in different process states;

Fig. 5

a schematic representation of the shrinking process;

Fig. 6

a view of the packaged item;

Fig. 7

a partial view of the object to be packed on a lifting table, and

Fig. 8

a schematic representation of the conveying process by the device according to the invention.

In the device according to the invention, a stack of goods 1 is on a pallet 2 arranged so that pallet 2 and stack of goods 1 the object to be packed form. The pallet 2 is arranged on a vertically movable lifting table 3, which component e.g. a belt conveyor system and which is on a base part 4 is stored.

The object to be packaged is arranged within a frame 5 which the individual components of the device are at least partially suspended. The film to be fed is unwound from a film roll 6 and in shape a film tube 8 via feed rollers 7 to the upper area of the packaging device guided. The upper area of the device forms a processing station 9, in which the film tube 8 to a film hood 20 with the desired length is formed. The following film tube is used for this 8 opened and gripped by means of a first gripping device 10. there gripper fingers 103 are placed in the film tube. Through on the gripping fingers 103 arranged reef rollers 11, the film tube 8 on the gripping fingers 103 funded. When the film tube 8 has reached the desired length, it is cut off by a cutter 12 and by one below it lying welding device 13 welded together so that a film hood 20 is formed.

The first gripping device consists of four suction boxes 100, which are attached to the respective Grasp the corners of the film tube to open it. On one edge of the Suction box, a gripping device 101 is provided with which the corresponding Foil tube edge can be pinched. Then the four Suction boxes 100 each moved on two parallel axes 102 such that the opened film tube essentially the contour of the object to be packaged Has. A detailed description of the opening system is in DE 43 26 827 to find. The first gripping device is preferably corresponding the suction / gripping device disclosed there. However, it is also possible to use other mechanical opening systems.

If the film hood 20 thus formed essentially the contour of the to be packaged Has taken object, it is to a second gripping device to hand over. The second gripping device has four grippers 16, which on one Shrink frames 15 are arranged. Between the first gripping device and the second gripping device, a heat shield 14 is provided which Processing station 9 separates from the shrinking space to the subsequent film hood not to be glued together by rising heat. The heat shield 14 can be formed, for example, by horizontally movable metal plates. Alternatively or additionally, a blower can be used to form an air curtain be used.

For the transfer of the film hood 20, the second gripping device is up moved to the first gripping device or the first gripping device downwards moved to the second gripping device, the four grippers 16 in the im in the ineffected state of the film hood 20. The first gripping device then moves in and down or folds the gripper arms inside and below to transfer the film hood 20.

As soon as the grippers 16 have taken over the film hood 20, the first gripping device again to the subsequent hose 8 to the next Form a film hood for the next packaging process.

The film hood 20 on the grippers 16 now moves down until the The top of the film hood 20 is arranged somewhat above the stack of goods. Subsequently becomes a heating device 17 in the form of several arranged in a ring Gas burner 17 or other suitable heating devices, such as electric radiators, Infrared heater and / or the like. Ignited or switched on and one Cooling device arranged above the gas burners 17 or the heating device 18 switched on in the form of a cooling air blower. At the same time, the film hood 20 together with the grippers 16, the shrink frame 15, the heating device 17 and the cooling device 18 moves down. When moving the film hood is shrunk onto the stack of goods 1, with the uniform shrinkage of the film hood prevents wrinkling. The film hood 20 is pulled over the stack of goods 1 practically without contact and at the same time shrunk onto the stack of goods 1 before contacting the stack of goods 1.

In the lower area of the stack of goods, the film hood 20 is folded over and under the lower edge of the stack of goods or the pallet shrunk so that the film hood 20 has a tight fit around the stack of goods 1 and the pallet 2.

As shown in Fig. 6, one can between the pallet 2 and the stack 1 Bottom film 22 may be provided so that the film hood 20 with the bottom film 22nd is welded. This enables a particularly sealed packaging of the Good stack 1.

The packaging process is explained below with reference to FIGS. 7 and 8. A stack of goods 1 'still to be packed on a pallet becomes the one according to the invention Device transported. The shrink frame 15 is still in the lower area of the stack of goods just packed 1. In the closed position prevents the shrink frame 15 that the still to be packed Item 1 'in the area of the frame 5 and the packaged item 1 can be promoted outside the area of the frame 5. Therefore are the areas of the shrink frame lying in the conveying direction of a conveyor belt 26 15 formed from movable sections 25 which are out of the transport route of the stack of goods 1 and 1 'can be moved.

As can be seen in FIG. 7, the sections 25 of the shrink frame 15 formed by suitable means to pivot the frame 5 in Release direction of the conveyor belt 26. With sections pivoted upwards 25 can still be packed object 1 'during the movement of the shrink frame 15 up to the next film hood in the Area of the frame 5 of the device moved and placed on the lifting table 3 become. Thereafter, the inventive method described above carried out and the subsequent film hood 20 shrunk onto the stack of goods 1 '. As soon as the shrinking process is finished, the packaged goods stack 1 'moved from the area of the frame 5 to the position 1' ', so that again the following stack of goods can be packed. This procedure shortens the cycle times considerably and thus contributes to the increase in performance of the system.

Claims (21)

1. Method of wrapping an article, especially a palleted stack of goods (1), with a shrinkable film (8, 20), wherein a film hood (20) is formed from a film tube and the film hood (20) is grasped, opened and gathered together by a gripping device (10, 11),
   characterised in that
   the film hood (20) is drawn over the article being wrapped and at the same time the film hood (20) is shrunk onto the article.
2. Method of wrapping an article according to claim 1, characterised in that the film hood (20) is shrunk onto the article by means of a heating device (17) by supplying heat above a gripping device (16).
3. Method of wrapping an article according to claim 1 or 2, characterised in that the film hood (20) is acted upon by heat before it has made contact with the article.
4. Method of wrapping an article according to any one of claims 1 to 3, characterised in that the supply of heat during shrinking of the film hood (20) is controllable.
5. Method of wrapping an article according to any one of claims 1 to 4, characterised in that the film hood (20) is opened by a first gripping device (10, 11) and is then transferred to a second gripping device (16).
6. Method of wrapping an article according to claim 5, characterised in that using the heating device (17) first the upper side of the film hood (20) is shrunk onto the article and then the heating device (17) and the second gripping device (16), which holds the film hood (20) in the reefed state, are moved downwards together.
7. Method of wrapping an article according to any one of claims 1 to 6, characterised in that the film hood (20) is sucked inwards at the underside of the article and is shrunk on over at least part of the underside of the article.
8. Method of wrapping an article according to any one of claims 1 to 7, characterised in that the film hood (20) is at its lower region welded to a bottom film (22).
9. Method of wrapping an article according to any one of claims 1 to 8, characterised in that the film hood (20) is cooled in the heated shrunk-on region.
10. Method of wrapping an article according to any one of claims 1 to 9, characterised in that when the film hood (20) is being applied, the second gripping device (16) and the heating device (17) are moved together.
11. Method of wrapping an article according to any one of claims 1 to 9, characterised in that for application of the film hood (20) the article is moved into the film hood.
12. Method of wrapping an article according to any one of the preceding claims, characterised in that the shrink frame (15) has movable parts (25) which, after the shrinking operation, are moved out of the transport region of the wrapped stack of goods (1) and a subsequent stack of goods (1'), and the stacks of goods (1, 1') are moved further during the movement of the shrink frame (15) upwards.
13. Device for wrapping an article, especially a stack of goods (1) arranged on a pallet (2), with a shrinkable film (8, 20), having:

    a feed device (6, 7) for feeding a film tube (8) to a processing station (10, 11, 12, 13);

    a first processing station (10, 11, 12, 13) for forming a film hood (20);

    a first gripping device (10, 11) for opening the film hood (20);

    a movable shrink frame (15) having a heating device (17) for shrinking the film hood (20) onto the article being wrapped,

    characterised in that
    for drawing the film hood (20) over the article there is provided a second movable gripping device (16) which is coupled to the shrink frame (15), so that the heating device (17), which is arranged and operable above the second gripping device (16), shrinks the film during application.
14. Device for wrapping an article according to claim 13, characterised in that the second gripping device (16), for application of the film hood (20), is couplable to the shrink frame (15).
15. Device for wrapping an article according to claim 13 or 14, characterised in that the second gripping device (16), for application of the film hood (20), is connected to the shrink frame (15).
16. Device for wrapping an article according to any one of claims 13 to 15, characterised in that the first gripping device (10, 11), for opening the film hood (20), comprises four gripping arms (103), which are arranged in a rectangle, and four suction boxes (100).
17. Device for wrapping an article according to any one of claims 13 to 16, characterised in that the second gripping device (16), for application of the film hood (20), has four gripping fingers (16) arranged in a rectangle, which gripping fingers are movable into the opened film hood (20) in order to take over the reefed film hood.
18. Device for wrapping an article according to any one of claims 13 to 17, characterised in that the shrink frame (15) has, above the heating device (17), a cooling device (18) for cooling the film hood (20).
19. Device for wrapping an article according to any one of claims 13 to 18, characterised in that the article being wrapped is arranged on a lifting platform (3), in the region of which there is provided an extractor fan.
20. Device for wrapping an article according to any one of claims 13 to 19, characterised in that the shrink frame (15) has at least one movable part (25) lying in the direction of transport of the stack of goods (1).
21. Device for wrapping an article according to claim 20, characterised in that the shrink frame (15) has on each of two opposite sides two movable parts (25) which are pivotable away out of the transport path of the stack of goods (1, 1').

Images