EP0601222A1 - Method and device for packaging of stacked articles more especially with a heat-shrinkable envelope - Google Patents

Abstract

For packaging, in particular, stacked articles with a heat-shrinkable film wrapping, the articles resting on a pallet (3) are firstly surrounded by a film wrapping (10), a lower film edge which passes around the articles on all sides extending down to below the pallet. Subsequently, at least the lower film edge (11) is heated so that the film material is converted to a plastic state and the lower film edge (11) is placed against the underside (13) of the pallet (3) provided with recesses (8) at that point. Since, in the case of film wrappings which are shrunk in this manner, the recesses (8) which are essential for transporting the pallet (3) are also covered by the material of the film wrapping (10) and destruction of this region of the film wrapping (10) entails disadvantages, it is proposed to deform the film edge (11), arranged in the region of the recess (8) of the pallet (3), by means of a ram (16), which is vertically displaceable relative to the pallet (3), until it rests against the contour of the recess (8). It is thus achieved that the film wrapping (10) rests flush against the pallet (3), even in the region of the recesses (8). The ram (16) is preferably designed in such a way that it can, to a certain extent, compensate for a lack of centricity relative to the recess (8). <IMAGE>

Description

The invention relates to a method for packaging in particular stacked goods with a heat-shrinkable film envelope, wherein the resting on a provided on its underside with palette pallets are initially surrounded with the film envelope so that an all-round rotating lower edge of the film reaches below the pallet and then at least the film edge is subjected to an artificially generated heat application, which is sufficient to convert the film material into a plastic state.

The invention further relates to a device for packaging in particular stacked goods with a heat-shrinkable film envelope, the goods rest on a provided with recesses on its underside pallet, with a device for slipping over the film envelope on the filled pallet, with a all-round bottom film edge to extends below the pallet, and with a device for all-round retraction of the film edge in the direction of the pallet center and a at least acting on the film edge heater.

A method and a device of the aforementioned type is known. A stack of goods arranged on a pallet, for example an industrial pallet or a europallet, is brought into a shrinking device by means of a conveyor, in FIG the put on the goods stack formed from the goods, a heat-shrinkable film sleeve and this is then shrunk with hot air. As a result, the film cover applies directly to the outer contour of the stack and thus serves not only the protection of the goods, for example against moisture, but also the position of the stack. In particular, with regard to this position assurance, it is important to surround not only the stack of goods themselves, but also serving as a support pallet with the film envelope. For this purpose, in the known device means are provided to pull a reaching to below the pallet sheet edge over a width of about 10 to 15 cm inward and shrink at the bottom of the pallet formed by three parallel runners. This part of the shrinking process is usually referred to as "under shrinking". The means required to produce the undershrink consist in the known device of a lifting device and a suction fan. The lifting device has a plurality of lifting rams, which retract before the slipping of the film envelope into recesses between the individual runners of the pallet, supported on the underside of the upper pallet surface and then lift the pallet with the goods stacked thereon something. In a next step, the film envelope is then pulled over and pulled by switching on the below the pallet suction fan, the lower edge of the film inward towards the center of the pallet. Thereafter, the shrinking of such retracted edge, wherein the quality of the undershrinking thus formed on the underside of the pallet can be further improved by immediately subsequent resuming the pallet.

A disadvantage of this known method and the device used for this purpose is that the lower shrinkage also closes the recesses between the mutually parallel runners of the pallet to the side. If such a pallet by means of a material handling device or a conveyor of a Recorded high-bay warehouse, the tines of the conveyor must penetrate into these recesses, the film of the lower shrinkage. Although this prepares, at least in heavily loaded pallets, for the relevant conveyors no difficulties, however, entrained pieces of film in the tines extending telescopic devices of the conveyor can clamp and lead there over time to costly disturbances.

In particularly light stacks of goods, it may also happen that the tines of the conveyor can not pierce the recesses covering undershrink, but the undershreshold has such a high tensile strength that is moved laterally when trying to retract the tines, along with the goods stacked thereon ,

The invention is therefore based on the object on a pallet and in particular on a standard pallet resting products so surrounded with a heat shrinkable film envelope that during the intended transport of goods so packaged destruction of the film envelope by the transport tines of a Regalbedien- and a material handling device can be avoided ,

To solve this problem, it is proposed with respect to the method that, following the measures mentioned above, arranged in the region of the recess of the pallet film edge is deformed by means of a vertically movable relative to the pallet punch to rest on the surfaces of the recess.

This ensures that the lower shrinkage, while applying to the underside of the pallet formed by the skids and thus has the required strength to secure the stack of goods. In the area of the recesses between the runners However, the film envelope is not freely stretched, but it is deformed until it rests against the contour of the recess. The recesses are therefore open at the side and do not need to be pierced by the tines of the respective conveyor for transporting the pallet. Thus, the above-mentioned disadvantages associated with conventional under-shrinkage are avoided.

In a preferred embodiment of the method, the deformation of the film edge in the region of the recess takes place only after previously the remaining film edge has been clamped due to the dead weight of the pallet between the bottom of the pallet and a base, in particular a conveyor. In this way, the strength of the lower shrinkage and thus the holding function of the film envelope for the stack of goods is improved overall.

The solution of the problem is characterized in terms of the aforementioned device by a arranged below the retracted film edge punch, which is designed to be movable vertically relative to the pallet until it rests in the recess of the pallet.

Although it is important for the function of the device in the first place that the pallet and stamp are movable relative to each other and thus the film edge can invest securely in the recess of the pallet, it is in view of the simplicity of construction nevertheless advantageous if, according to a development of the device, the punch itself is designed to be vertically movable.

With the invention it is further proposed that the stamp at the time of concern in the recess has exactly the same width as the recess.

For this purpose, it is proposed with a preferred embodiment that the punch is provided with two against the force of a spring spreadable to each other arranged jaws.

In order to avoid tearing of the film casing by the jaws, it is proposed with a further embodiment that both jaws are designed as freely rotatable spreader rollers.

Further, it is advantageous if both jaws are independently spreadable. In this way, a particularly simple adaptation of the position and effective width of the punch to the position and to the width of the recess on the underside of the pallet is possible.

In a further embodiment it is provided that the jaws are articulated pivotably at opposite ends of a common jaw carrier, which is arranged under the action of at least one return spring pivotally mounted on a liftable and lowerable support plate of the punch. This ensures that the respective stamp automatically adapts to the position and width of the respective recess under the action of return springs. In this way, tolerances in the dimensions of the pallets can be compensated. In particular, pallets of different standardization, for example industrial and Euro pallets, can be processed in one and the same shrinking device.

For quality assurance of the undershrink thus created, a further embodiment of the invention is characterized by a sensing device for checking the size of the free contour of the recess, which sensing device is connected downstream in the transport direction and is run over by the provided with the heat-shrunk film envelope pallet. Preferably, the sensing device is provided with a pivotable contour flap whose pivot angle is detected by a measuring and signaling device.

Fig. 1

In einer teilweisen Längsansicht eine mit einem Warenstapel versehene Palette auf einer Transporteinrichtung;

Fig. 2

eine weitgehend der Fig. 1 entsprechende Ansicht mit zusätzlicher Darstellung einer Hubeinrichtung sowie einer Einrichtung zum Verformen des unteren Folienrandes;

Fig. 3

eine der Fig. 2 entsprechende Darstellung während eines anderen Arbeitsschrittes;

Fig. 4

eine der Fig. 2 entsprechende Darstellung während eines wiederum anderen Arbeitsschrittes;

Fig. 5

eine Draufsicht auf die Vorrichtung gemäß den Figuren 1 bis 4;

Fig. 6

in einem Teilschnitt eine Detaildarstellung zu der Vorrichtung nach Fig. 5 und

Fig. 7

eine perspektivische Darstellung einer Unteransicht einer mit der Vorrichtung gemäß den Figuren 1 bis 6 fertiggestellten, beladenen Palette.

Further details and advantages of the subject matter of the invention will become apparent from the following description of an embodiment. Show:

Fig. 1

In a partial longitudinal view of a pallet provided with a stack on a transport device;

Fig. 2

a view corresponding largely to Figure 1 with additional illustration of a lifting device and a device for deforming the lower edge of the film.

Fig. 3

one of the Figure 2 corresponding representation during another step;

Fig. 4

one of the Figure 2 corresponding representation during another turn step;

Fig. 5

a plan view of the device according to Figures 1 to 4;

Fig. 6

in a partial section a detailed representation of the device according to Fig. 5 and

Fig. 7

a perspective view of a bottom view of a finished with the device according to the figures 1 to 6, loaded pallet.

Fig. 1 illustrates a transport device that is part of a combined Folienüberzieh- and heat shrink device. The transport device consists of three horizontal, parallel transport tracks 1 with arranged at the top of transport rollers 2 or chains of a chain conveyor together. On the transport device is a pallet 3 in the form of a normalized Euro pallet or a likewise standardized industrial pallet.

The pallet 3 consists of three in the manner of runners parallel to each other arranged timber 4, on which a support platform is attached. The support platform is composed of a first layer of slats 5, which extend at right angles to the woods 4, and a further layer of slats 6, which extend parallel to the woods 4 and directly form a support for a stack of goods 7. Other slats can, as shown in FIG. 1 reveals be attached to the underside of the woods 4.

Due to the limited width of the woods 4 are formed between these two parallel recesses 8, in the transport of the pallet 3 with the goods stacked thereon prongs of a conveyor, such as a shelf operating or a material handling equipment, retract. By raising the tines they engage under the lower layer of slats 5 and thus lift the pallet 3 with the goods stack 7 arranged thereon.

Fig. 2 shows the pallet 3 with the goods stacked thereon in a somewhat advanced position on the conveyor. In this position, the pallet 3 is lifted by a few centimeters by means of a vertically operating, retracting into the recesses 8 lifting device 9. Also in this position, a closed-top, heat-shrinkable film envelope 10 is placed over the stack of goods 7, whose length is dimensioned so that the all-round circumferential lower edge of film 11 extends below the pallet 3. Then, a suction fan 12 is put into operation, which is shown in plan view in Fig. 5. By means of the suction effect of the suction fan 12, the lower film edge 11 of the film casing 10 is pulled on all sides in the direction of the center of the pallet, so that it rests against the underside 13 of the pallet 3. The thus transposed, about 10 to 15 cm wide edge of the film 11 is then subjected to a shrinking process by at least this portion of the heat-shrinkable film envelope 10 subjected to a sufficient heat becomes. As a result, the film casing 10 contracts and lies firmly against the underside 13 and optionally the side surfaces of the pallet 3. At the same time or subsequently, the remaining part of the film casing 10 is also subjected to a shrinkage process. In order to improve the application of the film edge 11 to the underside 13 of the pallet 3, before or during the shrinking process, the lifting device 9 lowered again and thus the film edge 11 between the bottom 13 of the pallet 3 and the transport rollers 2 are clamped. As a result, the weight of the pallet 3 with the goods stacked thereupon supports the sealing of the undershrink thus formed.

In Fig. 3 the finished shrunken pallet 3 is shown. This representation can also recognize that between the top of the pallet 3 and the stack of goods 7 as moisture protection, an additional film 14 may be arranged, the laterally projecting edge 15 is sealed during shrinkage of the film casing 10 with this.

Details of the technique of heat application are not shown in the figures. However, a suitable ring burner is shown and described for example in EP-0 133 462 B1.

Fig. 3 also reveals that the heat-shrunk film edge 11 spans the two recesses 8 laterally free. In order to eliminate the disadvantages associated therewith, a device for deforming the lower film edge 11 in the region of the recesses 8 is provided. The device 16 consists in the embodiment of a total of four hydraulically raisable and lowerable punches 16, which are arranged exactly below the recesses 8 freely spanning foil edge 11. In contrast, the lifting rams of the lifting device 9 are located further inside the pallet 3, ie they do not detect the foil edge 11 of the foil wrapper 10 during their lifting movement.

Each of the four stamps 16 consists of a rigidly arranged on the respective hydraulic cylinder support plate 17, on which a jaw carrier 18 is pivotally mounted. Return springs 19 between the support plate 17 and jaw carrier 18 cause that with unloaded jaw carrier this assumes an axial neutral position relative to the support plate 17.

On the jaw carrier 18 symmetrically two mutually spreadable jaws 20a, 20b articulated. The outer, mutually spreadable ends of these jaws 20a, 20b are formed as freely rotatable spreading rollers 21a, 21b, the axis of rotation extends in each case parallel to the alignment direction of the recess 8. A tension spring 22 connects the two jaws 20a, 20b of each punch 16 with each other and causes the obliquely outwardly directed jaws 20a, 20b can be spread only by the action of force.

As shown in FIG. 4, this force is applied at the latest when the punches 16 are moved hydraulically into the recesses 8. As soon as the spreader rollers 21a, 21b come into abutment with the foil edge 11 in the respective recess 8, the jaws 20a, 20b, which are slightly inclined relative to one another in the neutral position, expand. As a result of the freely rotatable mounting of the spreader rollers 21a, 21b they can run along the film and compensate for the inevitably occurring stretching of the film insofar that in the film no excessive local tensile stresses occur, which would lead to a rupture of the film. The stretching and deformation of the film edge 11 is completed as soon as the jaws 20a, 20b abut with the spreading rollers 21a, 21b in the upper corners of the recess 8. In order to achieve as close as possible a connection of the film with the pallet 3, the diameter of the spreader rollers 21a, 21b should be as small as possible.

The above-described application of the film edge 11 in the region of the recesses 8 takes place immediately after production of the undershrink, since the film is then still in the plastic state and can be permanently deformed.

In the right part of Fig. 4 it is shown that by the use of the return springs 19, the tension spring 22 and the independently spreadable jaws 20a, 20b of the punch 16 is capable of the deformation of the film edge 11 in the event of a lateral offset between Perform punch 16 and recess 8. This makes it possible to process inaccurately processed pallets. Since centering problems are compensated, the device can also handle different pallet dimensions. In any case, the film edge 11 is exactly adapted to the contour of the respective recess 8.

This work result is clearly shown in Fig. 7.

According to FIGS. 5 and 6, a scanning device 23 for checking the size of the free contour of the recess 8 is provided in the further course of the transport device. This sensing device 23 consists of two pivotable about an axis 24 contour flaps 25 which protrude when passing through the pallet 3 in the recesses 8. If the film edge 11 is not sufficiently adapted to the contour of the recess 8, this leads to a pivoting of the contour flap 25, which is detected by a measuring and signaling device 26, which then reports an interference signal.

LIST OF REFERENCE NUMBERS

1

transport path

2

transport roller

3

palette

4

woods

5

battens

6

battens

7

stack of goods

8th

recess

9

lifting device

10

film cover

11

film edge

12

aspirator

13

bottom

14

foil

15

edge

16

stamp

17

support plate

18

jaw carrier

19

Return spring

20a

jaw

20b

jaw

21a

spreader

21b

spreader

22

mainspring

23

sensing device

24

axis

25

contours flap

26

Measuring and signaling device

Claims (11)

A method for packaging in particular stacked goods with a heat-shrinkable film envelope, wherein the resting on a bottom provided with recesses pallet goods are first surrounded with the film envelope so that an all-round rotating lower edge of the film extends below the pallet and then at least the film edge of a subjected to artificially generated heat application, which is sufficient to convert the film material into a plastic state,
characterized,
in that subsequently the foil edge (11) arranged in the region of the recess (8) of the pallet (3) is deformed by means of a punch (16) movable vertically relative to the pallet (3) until it bears against the surfaces of the recess (8). A method according to claim 1, characterized in that the deformation of the film edge (11) in the region of the recess (8) takes place only after previously the remaining film edge (11) due to the dead weight of the pallet (3) between the bottom (13) of the pallet (3) and a base, in particular a conveyor (1) has been clamped. Apparatus for packaging in particular stacked goods with a heat-shrinkable film casing, the goods lying on a pallet (3) provided with recesses (8) on its underside (13), with a device for slipping the film casing (10) over the filled pallet ( 3), wherein an all-round lower Film edge (11) extends below the pallet (3), and with a device (12) for pulling all around the film edge (11) in the direction of the center of the pallet and a at least on the film edge (11) acting heater
marked by
a punch (16) arranged below the drawn-in film edge (11), which punch is designed to be movable vertically relative to the pallet (3) until it rests in the recess (8) of the pallet (3). Apparatus according to claim 3, characterized in that the punch (16) is itself designed to be vertically movable. Apparatus according to claim 3, characterized in that the punch (16) at the time of concern in the recess (8) has exactly the same width as the recess (8). Apparatus according to claim 5, characterized in that the punch (16) is provided with two jaws (20a, 20b) which are spreadable relative to one another and against the force of a spring (22). Apparatus according to claim 6, characterized in that both jaws (20a, 20b) are designed as freely rotatable spreading rollers (21a, 21b). Apparatus according to claim 6, characterized in that both jaws (20a, 20b) are independently spreadable. Apparatus according to claim 6, characterized in that the jaws (20a, 20b) are pivotably articulated at opposite ends of a common jaw carrier (18), which under the action of at least one return spring (19) pivotally mounted on a liftable and lowerable support plate (17). of the punch (16) is arranged. Device according to one of claims 3 to 9, characterized by a downstream in the transport direction of the filled pallet (3) and provided by the with the heat-shrunk film envelope (10) pallet (3) touch device (23) for checking the size of the free contour of the recess (8th). Apparatus according to claim 10, characterized in that the sensing device (23) is provided with a pivotable contour flap (25) whose pivot angle is detected by a measuring and signaling device (26).

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