EP0633186A1 - Method and apparatus for wrapping products - Google Patents

Abstract

The invention relates to a method for wrapping products, if appropriate supported on a pallet (10) or the like, with (1) a tubular or hood-shaped stretch foil (2, 3), especially from cubic or cuboid product stacks consisting of product layers palletised one above the other in a plurality of layers, in which method the foil portion forming the side-face wrapping is gathered and transversely stretched before being drawn over the product, and in which method the foil, when being drawn over the product, is at least temporarily pressed (12) laterally against an abutment, before the release of its lower edge portion, in the region of the lower product edge portion and/or of the pallet, and the lateral pressure is cancelled when the foil has been firmly laid over the full height against the product or at least partially against the pallet, characterised in that the foil, while being pressed down, is moved (20) inwards relative to its draw-over contour in the pressure region. <IMAGE>

Description

The invention relates to a method for wrapping piece goods with a tubular or hood-shaped stretch film according to the preamble of claim 1 and a device suitable for this according to the preamble of claim 2.

When pulling a stretch film hood over a stack of general cargo possibly arranged on a pallet, it has been shown that the lower edge region of the film, which is intended to reach under the general cargo or the pallet itself with a so-called understretch, in order to create a weather-resistant and transport-safe loading unit , has the tendency to pull up at least partially over the pallet or the underside of the piece goods. This is particularly the case when the film material is not only subjected to horizontal transverse stretching but also to vertical longitudinal stretching.

This disadvantageous effect results when the film held and guided by the lifting frame during the pulling process in the lower end section of the film wrapping already slides off the lifting frame when the film section above it has not yet been able to lay firmly against the piece goods or the pallet.

In order to prevent the lower edge of the film from sliding up, it is known from DE 90 01 319 U1 to provide movable clamping jaws which press the film in the lowest position of the lifting frame against the piece goods or the pallet arranged below it, before the lower edge of the film Swivel brackets of the lifting frame is released, which have pulled the film hood over the stack of goods. In addition, additional clamping jaws can be provided in this device underneath the pallet and thus the lifting frame (= reefing and stretching frame if necessary), which, after actuation of a parallel link mechanism by piston-cylinder units, grips the lower film edge by clamping and moves it under the pallet.

Such jaws, including their drive and their control, require considerable additional effort. In addition, it has been shown that the desired understretch often does not come about (at least in part) because the film pulls up over the underside of the pallet or piece goods after it has detached from the lifting frame, especially when a considerable vertical stretch is provided. To avoid these difficulties, it has therefore already been proposed (see German patent application P 40 19 127.3-27) to reduce the pulling speed in the final pulling phase and, if necessary, to reduce the film relative to its pulling contour during pressing. or move inwards within the pressure range.

DE 40 19 041 C1 has proposed a method and a device for wrapping piece goods with stretch film, by means of which the lower edge section of the film wrapping to be reinforced compared to the rest of the film wrapping during the wrapping process. For this purpose, the lower edge section of the stretch film hood, in the case of essentially already completely wrapped article side surfaces or the wrapped pallet, before reaching under the piece goods or the pallet, forming a double-layered film edge section extending beyond the underside of the piece goods or the pallet from a first lowered position, the under the general cargo or in the area of the pallet, raised again and only then released. In this case, the reversible drivable reefing rollers can optionally alternatively serve to be brought into engagement with the film again in the second lowering position in order to bring about the wrinkle effect sought there in order to reinforce the lower film edge. However, they have no influence on the above problem.

The present invention is based on the object of specifying a method and a device by means of which the desired understretch can be implemented simply and safely.

As a solution to the procedural part of the above object, it is provided according to the invention that the film is moved inward in the pressing area relative to its covering contour during the pressing. It has been shown that there is often a secure understretch even if the pulling speed is not reduced in the final pulling phase, as is provided in DE-OS 40 19 127. As a result of this measure, the film is correspondingly relaxed in its lower edge area, accordingly fits well in the understretch area and can then no longer be pulled up over the underside of the pallet or the piece goods.

As a solution to the device-related part of the object, the invention provides that as a film moving device the reef rollers are used in conjunction with the lifting frame serving as an abutment. This measure makes it possible to dispense with additional clamping jaws or the like and considerably simplifies the construction, in particular if the lifting frame is also a reefing and stretching frame and not only serves as an abutment when pressed on, but also as a movement device for carrying it out the measure according to the invention.

Fig. 1

eine etwas schematische räumliche Darstellung eines mit einer Stretchfolienhaube zu überziehenden Stückgutstapels, wobei die Stretchfolienhaube aus einem Seitenfaltenschlauch gebildet wird, der in Fig. 1 an seinem freien Endabschnitt bereits von dem Hubrahmen aufgenommen worden ist;

Fig. 2

in einer Fig. 1 entsprechenden Darstellung die Anordnung gemäß Fig. 1 nach Bilden einer Stretchfolienhaube;

Fig. 3

in einer Darstellung gemäß den Fig. 1 und 2 die gemäß Fig. 2 gebildete Stretchfolienhaube nach dem/beim Querstretchen;

Fig. 4

in einer Darstellung gemäß den Fig. 1 bis 3 einen Zwischenzustand beim Überziehen des Stückgutstapels mit einer Stretchfolienhaube;

Fig. 5

eine Seitenansicht eines bügelförmigen (Hub-)Rahmenabschnittes nebst dessen Stütze in Richtung des Pfeiles V in Fig. 6 gesehen;

Fig. 6

eine Draufsicht auf zwei (von vier) bügelförmige (Hub-)Rahmenabschnitte;

Fig. 7

eine teilweise schematisierte Seitenansicht auf einen auf einer Palette abgestützten Stückgutstapel mit einem bügelförmigen Rahmenabschnitt sowie einer Andrückeinrichtung in der Überzieh-Endphase, und

Fig. 8

in einer Darstellung gemäß Fig. 7 (ausschnittsweise) die fertige Ladeeinheit.

The invention is explained below using an exemplary embodiment with reference to a drawing. It shows:

Fig. 1

a somewhat schematic spatial representation of a piece of goods to be covered with a stretch film hood, the stretch film hood being formed from a gusseted tube which has already been received by the lifting frame in FIG. 1 at its free end section;

Fig. 2

in a representation corresponding to FIG. 1, the arrangement according to FIG. 1 after forming a stretch film hood;

Fig. 3

in a representation according to FIGS. 1 and 2, the stretch film hood formed according to FIG. 2 after / during transverse stretching;

Fig. 4

in an illustration according to Figures 1 to 3, an intermediate state when covering the piece goods stack with a stretch film hood.

Fig. 5

6 shows a side view of a bow-shaped (lifting) frame section along with its support in the direction of arrow V in FIG. 6 seen;

Fig. 6

a plan view of two (out of four) bow-shaped (lifting) frame sections;

Fig. 7

a partially schematic side view of a stack of packaged goods supported on a pallet with a bow-shaped frame section and a pressing device in the final pulling phase, and

Fig. 8

7 (detail) of the finished loading unit.

1 shows a block-shaped piece goods stack, designated as a whole by 1, which consists of several layers of piece goods parts which are intended to be wrapped with a stretch film hood 2 in order to form a loading unit. The stretch film hood 2 is formed from a gusseted tube 3, which is fed to the device according to the arrows 8 from a gusseted tube supply, not shown, the free end of the gusseted tube 3 according to FIG 3) has been included.

As has been indicated in Fig. 2, the gusseted tube 3 is welded at a distance from its free end by means of a welding device 4, which consists essentially of two welding strips, so that a transverse seam 5 is formed, and above the transverse seam 5 by means of a not shown Separating device separated to form a stretch film hood 2, the side surfaces of which, in the state shown in FIG. 2, have already been substantially raised onto the lifting frame 9 (by means of a reefing device).

From the state shown in FIG. 2, the four frame-like (lifting) frame sections 9 'essentially forming the lifting frame and assigned to the corner regions of the piece goods stack 1 are moved apart in the direction of arrows 6 for the purpose of transverse stretching of the stretch film hood 2. Then the stretched stretch film hood 2 according to FIG. 4 is pulled over the stack of goods 1 by means of the lifting frame 9, which also forms a reefing frame, FIG. 4 showing an intermediate state in which the stack of goods 1 is already half wrapped.

From the position shown in FIG. 4, the lifting frame 9, which can be driven by means of a drive (not shown), then moves further downward, finally into a position as can be seen in FIG. 7, only a single bow-like frame section 9 ′ being recognizable in FIG. 7 is, the other bow-like frame sections 9 'but are formed accordingly and are at the same height level.

Before the further wrapping process is explained in detail below, the specific configuration of the bow-like frame sections 9 'of the lifting frame 9 in the exemplary embodiment shown is to be explained in more detail in particular in FIGS. 5 and 6, and reference should first be made to the fact that the piece goods stack 1 - As can be seen from FIGS. 1 to 4 - is supported on a (one-way) pallet 10 with a plate top 10 '.

As has already been stated, the lifting frame 9 consists of four substantially C-shaped bracket-like frame sections 9 ', each of which is provided with a plurality of through-bores 13, which are connected to a vacuum source, and in each case engages with films during operation located section of the outside of the relevant lifting frame section 9 'open. The vacuum source indicated schematically in FIG. 6 is designated by 14.

Each bow-shaped frame section 9 'is supported by a support 17 (see FIGS. 5 and 6) formed by a curved, conical sheet metal, the supports 17 each having a recess 18 in the central region. Otherwise, the through bores 13 connected to the vacuum source 14 are connected to a control device 16 (see FIG. 6), by means of which the vacuum can be controlled.

As can be seen from FIG. 7, the bow-like frame sections 9 ′ of the lifting frame 9 in the exemplary embodiment shown are moved to slightly below the upper side 10 ′ of the pallet 10 during the pulling-over process, wherein it can be seen from FIG. 7 that the side surfaces of the stretch film hood 2 already substantially envelop the piece goods stack in this intermediate position. Nevertheless - as can be seen from FIG. 7 - the film 2 or 3, which is still in frictional engagement with the bracket-like frame sections 9 'of the lifting frame 9, does not yet adhere to these in the region of the lower section 1' of the piece goods stack 1 and not yet applied to the pallet 10. If, in particular in the case of considerable vertical stretch of the film 2 or 3, the lifting frame 9 was disengaged from the film in the state according to FIG. 7, this could have the consequence that it extends beyond the underside of the stack 1 or the Pallet top 10, at least the upper layer 11 of the pallet 10 pulls upwards, so that the desired understretch does not occur, in which the film 2 or 3 engages under the upper layer 11 of the pallet 10 (see FIG. 8).

In order to ensure this, a pressure device 12, shown schematically in FIG. 7, is provided, which is the reefing device, by means of which the gusseted tube 3 was previously thrown onto the supports 17 of the bow-like frame sections 9 'of the lifting frame 9 is. The reefing rollers essentially forming the pressing device 12 are pressed in the position shown in FIG. 7 according to the arrow 15 on the piece goods 1 or in a somewhat lower position on the upper layer 11 of the pallet 10. Only then do the bow-like frame sections 9 'move downward according to the arrow 19, that is, out of engagement with the film 2 or 3, whereby they have already been moved inwards according to the arrow 20 (ie onto the piece goods 1 or the pallet 10) become.

The consequence of this is that the film 2 or 3 can “rest” with an understretch section 21 on the underside of the upper pallet layer 11 due to the pressure by means of the pressing device 12, the corresponding measure also evident on the lower layer 22 of the pallet is possible, as has been indicated in FIG. 8 with respect to the bottom stretch section 21 'in a dash-dotted line, or with a loading unit not supported on a pallet 10 or the like directly below the piece goods stack 1, as can be readily recognized by the person skilled in the art is.

It should also be pointed out that, within the scope of the inventive concept, numerous variations or modifications are evidently possible which go (far) beyond the exemplary embodiment described above and shown in the drawing. For example, the lifting frame does not of course have to consist of bow-like sections of the type in question (see FIGS. 5 and 6), but can, for example, consist of a closed frame, the individual legs of which (for the purpose of transverse stretching) can be telescoped.

1

Stückgutstapel 1' unterer Abschnitt (von 1)

2

Stretchfolienhaube

3

Seitenfaltenschlauch

4

Schweißvorrichtung

5

Quernaht

6

Pfeile

7

-

8

Pfeile

9

Hubrahmen 9' bügelartige (Hub-)Rahmenabschnitte

10

Palette 10' Palettenoberseite

11

Oberschicht (von 10)

12

Andrückeinrichtung

13

Durchgangsbohrungen

14

Unterdruckquelle

15

Pfeil

16

Steuerungseinrichtung

17

Stütze (für 9')

18

Ausnehmung (in 17)

19

Pfeil

20

Pfeil

21, 21'

Unterstretchabschnitt

22

Unterschicht (von 10)

Furthermore, the pressing device 12 can be designed in a wide variety of ways and, in particular, does not need to be a component of the reefing device, as is most expedient, but can be realized, for example, by holding the lifting frame 9 Foil 2 and 3 in the negative pressure applied through the through holes 13 are held firmly on the lifting frame, while the latter is moved closer from its upper pulling position in the pull-over final phase to the packaged goods 1 and the foil 2 or 3 has the opportunity to firmly attach itself to create the piece goods stack 1 or the pallet 10 or a part thereof.

1

General cargo stack 1 'lower section (from 1)

2nd

Stretch film hood

3rd

Gusseted hose

4th

Welding device

5

Cross seam

6

Arrows

7

-

8th

Arrows

9

Lifting frame 9 'bow-like (lifting) frame sections

10th

Pallet 10 'pallet top

11

Upper class (out of 10)

12th

Pressing device

13

Through holes

14

Vacuum source

15

arrow

16

Control device

17th

Support (for 9 ')

18th

Recess (in 17)

19th

arrow

20th

arrow

21, 21 '

Bottom stretch section

22

Lower class (out of 10)

Claims (2)

Method for wrapping piece goods (1), possibly supported on a pallet (10) or the like, with a tubular or hood-shaped stretch film (2, 3), in particular piece or cube-shaped piece goods stacks consisting of layered piece goods layers stacked on top of one another (1), in which the film section (2, 3) forming the side surface covering is reefed and stretched over the piece goods (1) before being pulled over, and in which the film (2, 3) is pulled over the piece goods (1) before pulling over Let go of its lower edge section in the area of the lower piece goods edge section or / and the pallet (10) at least temporarily pressed laterally against an abutment and the side pressure is released when the film (3) is at full height against the piece goods (1) or at least partially fixed to the pallet (10), characterized in that the film (3) is pressed relative to it during the pressing its outer contour is moved inwards in the pressing area. Device for wrapping piece goods (1), possibly supported on a pallet (10) or the like, with a tubular or hood-shaped stretch film (2, 3), in particular staple or cube-shaped piece goods pieces consisting of multi-layered layers of piece goods (1), with a stirrup-like frame section (9 '), preferably consisting of a plurality of (in plan view) substantially L-shaped or C-shaped, essentially arranged in a (horizontal) plane, and each of these stirrup supports holding drivable Reefing and stretching lifting frame (9), onto which the film section (2, 3) forming the side surface covering is to be mounted by means of a reefing device having reefing rollers before being coated onto the piece goods (1), and by means of which the opened film (2) in front of the Cover is to be pulled across, the film (2 or 3) before releasing its lower edge section by a pressing device (12) in the lower part rich of the piece goods (1) to this or the pallet (10) to be pressed, and wherein the pressing device (12) is to be brought out of engagement with the film again when the film (2 or 3) at the lower end portion of the piece goods (1) and possibly the upper end section of the piece goods (1) and possibly the upper end section (11) of the pallet (10), in particular for carrying out the method according to claim 1, characterized in that the reefing rollers (12) at the same time form the pressing device (12).

Images