EP2910474A1 - Method and device for enclosing an object with a tubular packaging film - Google Patents

Abstract

A method of wrapping an article (2) with a tubular wrapping film (4) comprising the steps of: providing a stock (6) of tubular flat folded packaging film, stripping the packaging film from the supply, and transporting the wrapping film to an opening station (40) Separating a film section required for a wrapping operation, transporting the wrapping film before reaching the opening station by frictionally engaging between at least two endlessly circulating conveyor elements (22, 24) moved in a transport direction, wherein the conveyor elements are connected at a discharge end about two parallel deflecting rollers (26b ) are deflected and separated from each other, opening of the film section, impingement of the film section on a Reffeinrichtung (44) wrapping of the article, wherein the film section before and / or during opening at least partially treated antistatic wi and electrostatic charges on the packaging film are at least partially neutralized by antistatic treatment of the packaging film by rod-shaped ion generators (60), each arranged parallel and adjacent to a deflection roller (26b) disposed at the discharge end, and apparatus for carrying out the method.

Description

The invention relates to a method and a device for wrapping an article with a tubular packaging film, for example according to DE 3918311 A1 ,

When packaging objects such as stacks of articles with a tubular packaging film, which is rolled up flat in the storage state in the form of a supply roll flat, it often causes difficulties in opening the film to an open film tube or a film hood due to electrostatic charges of the film. Such charges may already form upon removal of a required film portion from the supply roll, and / or during transport of the film portion from the supply roll to an opening station where the film is opened, patted, and finally drawn over the article to be packaged. The film can then be difficult to open or uncontrollably adhere to adjacent plant parts, which can make the expiration of the packaging process considerably more difficult.

From the US 3,209,513 a device for film packaging is known in which a flat folded, unilaterally open film is peeled off a roll and treated antistatic.

The object of the invention is to provide a method and a device for wrapping an article with a tubular packaging film, in which or the above problem is solved improved.

To achieve this object, the invention first proposes a method for wrapping an article with a tubular packaging film, comprising the steps of: providing a supply of tubular, flat folded packaging film, removing the packaging film from the supply and transporting the packaging film to an opening station, separating a film section required for a wrapping operation, transporting the wrapping film before reaching the opening station by frictionally engaging between at least two endless conveyor elements moving in a transport direction, wherein the conveying elements are deflected at a discharge end about two parallel guide rollers and separated from each other, opening the film section , Contacting the film section to a reefing device and wrapping the article, wherein the film section before and / or during opening at least bere For example, it is antistatically treated and electrostatic charges on the packaging film are at least partially neutralized by antistatic treatment of the packaging film by rod-shaped ion generators, which are each arranged parallel to and adjacent a deflection roller arranged at the delivery end.

It is preferably provided that the inner generators are arranged outside of an inner region enclosed by the tubular film section, so that in particular outer surfaces of the film section are antistatically treated or are charged with ions. As a result, the conveying elements can also be antistatically treated with the film material.

It can be provided that the entire film section is treated antistatically before and / or during opening.

The wrapping film can be stored and fed as a gusseted tube having a front wall, a rear wall and two side walls folded therebetween, with the front wall and the back wall being antistatically treated before and / or during opening.

It can be provided that after the beginning of the opening, the side walls are treated inside and / or outside antistatic.

Ion generators may be disposed within the interior of the film section to antistatically treat interior surfaces of the film section.

Preferably, the invention provides that the packaging film is separated before reaching the opening station, for example, immediately after a required film length has been deducted, and the packaging film is transported in the form of the separated film section up to the opening station.

The packaging film can be opened after leaving the conveying elements, wherein the front and rear walls in the region of the conveying elements lie on one another and, after leaving the conveying elements, are invertedly opened and antistatically treated in a V-shape.

The antistatic treatment may include monitoring or detecting the electrostatic charge of the packaging film, ion generation by means of discharge electrodes, and an air purge directed from the discharge electrodes to the packaging film. The generation of ions may be controllable, for example as a function of the detected charge of the packaging film, and the air purge may be controllable, for example also depending on the electrostatic charge of the packaging film. The intensity of the ion generation and / or flow rate of the air purge can are further controlled in response to a withdrawal speed of the packaging film, with which it is transported to the opening station.

To assist the antistatic treatment can be provided that the conveyor elements are continuously discharged during operation.

The object underlying the invention is further achieved by a device for wrapping an article with a tubular packaging film, comprising: a supply of tubular, flat folded packaging film, a trigger device for removing the packaging film from the supply, a separating device for separating a film section, a Film transport device for transporting the packaging film to an opening device, wherein the opening device comprises gripping elements for detecting the film section, wherein the film transport device comprises a first endless revolving conveyor element and a second endless revolving conveyor element pressed against the first conveyor element, which can be driven in a transport direction and between which Foil section between the separating device and a discharge end is frictionally receivable, a Reffeinrichtung for receiving the film section, a Üb forming means for wrapping the article with the film section; means for neutralizing electrostatic charges on the packaging film, disposed at the discharge end of the film transport means spaced above the opening means and formed by two or more rod-shaped ion generators, each parallel and are arranged adjacent to one of two arranged at the discharge end parallel pulleys of the film transport device.

The ion generators are preferably arranged outside an ion region enclosed by the tubular film section, so that in particular outer surfaces of the film section are antistatically treated or are charged with ions. Conveniently, each ion generator is deflected by an adjacent one Conveyor not further than 10 mm, 20 mm, 50 mm, 10 mm, 150 mm or 200 mm away.

Ion generators may be disposed within the interior region to antistatically treat or ionize interior surfaces of the film section.

The film transport device is suitable both for the transport of packaging film, which is deducted from the stock, as well as for the transport of an already separated film section, depending on where the separation device is arranged spatially.

The gripper elements may be grasping forceps or, alternatively, surface aspirators with which the packaging film or the foil section can be grasped at a front end by suction, opened and pulled onto the reefing device.

It can be provided that a film path is formed between the discharge end of the film transport device and the reef device, along which the film section is moved, opened and picked up, the device for neutralizing electrostatic charges being spaced up to 300 mm, 200 mm, 150 mm 100 mm, 50 mm, 20 mm or 10 mm from the film path is arranged. Furthermore, it can be provided that the device for neutralizing electrostatic charges is arranged at a distance of up to 300 mm, 200 mm or 100 mm from the discharge end of the film transport device.

The invention further preferably provides that the first and / or the second conveying element is designed as an at least partially electrically conductive transport belt. The transport belt may be formed in multiple layers with at least one at least partially electrically conductive layer. The electrically conductive layer may be provided with metal threads, metal mesh or carbon fibers. It can be provided that one with the Packaging film coming into contact surface of the first and / or the second conveying element is formed at least partially electrically conductive. For example, a metal mesh, metallic wires arranged parallel to the direction of rotation or a conductive surface coating may be provided on the surface.

It can be provided that in each rod-shaped ion generator in the longitudinal direction behind a series of ion nozzles are provided, each working by means of corona discharge and air purging. Each ion nozzle has a discharge-tip central discharge rod and an air purge passage concentrically surrounding it, which in turn is surrounded by an annular counter electrode connected to a ground plate. The discharge rod and the grounded counter electrode are connected in operation to a high voltage AC, for example, five or six kV, with an air flow generated by the air purging channel in the direction of the packaging film to be discharged generates an intense ion transport. In particular, the AC voltage may be modulated in a pulse shape to effect a maximum ion generation cycle. Depending on the polarity of the charge of the packaging film to be discharged, the positive or negative pulse portions of the pulsed AC voltage can be increased in voltage or obtain a larger pulse width, so that a flexible ion generation (positive or negative ions) is possible. Circuit technology in terms of an equivalent circuit diagram, the discharge rod is controlled alternately in the cycle of alternating voltage (high frequency) longer or shorter connected to positive or negative DC voltage (high voltage), resulting in a controlled polarity of the generated ion cloud.

• Fig. 1 eine schematische perspektivische Ansicht einer erfindungsgemäßen Vorrichtung zum Umhüllen eines Gegenstands mit einer Verpackungsfolie zeigt,
• Fig. 2 eine Ansicht der Vorrichtung nach Fig. 1 aus einer anderen Richtung zeigt,
• Fig. 3 eine schematische Seitenansicht der Vorrichtung nach Fig. 1 zeigt,
• Fig. 4 eine vergrößerte Teilansicht der Darstellung nach Fig. 2 zeigt,
• Fig. 5 eine vergrößerte Teildarstellung der Seitenansicht nach Fig. 3 zeigt,
• Fig. 6 eine vergrößerte Teildarstellung aus Fig. 1 zeigt, und
• Fig. 7 schematisch eine Ausführungsvariante mit mehrerenTeilförderelementen zeigt.

The invention will be explained with reference to an embodiment, reference being made to a drawing in which

• Fig. 1 shows a schematic perspective view of a device according to the invention for enveloping an article with a packaging film,
• Fig. 2 a view of the device according to Fig. 1 from another direction,
• Fig. 3 a schematic side view of the device according to Fig. 1 shows,
• Fig. 4 an enlarged partial view of the illustration after Fig. 2 shows,
• Fig. 5 an enlarged partial view of the side view Fig. 3 shows,
• Fig. 6 an enlarged partial view Fig. 1 shows, and
• Fig. 7 schematically shows a variant with several Teilförderelementen.

The figures show a basically known device for coating a stack of goods 2 with a tubular packaging film 4, which is usually stretch or stretch film, in contrast to the previously used mostly to be applied by applying heat to the stack shrink film.

The device has a holder not shown in detail for receiving a film roll 6, which forms a supply of packaging film 4, wherein the film is wound in the form of a gusseted tube, in which a front wall and a rear wall with folded side walls folded thereon.

A guide roller 8 and a pair of feed rollers 10 exemplify a film take-off device that can be controlled to peel a film portion having a predetermined length. In the unwinding 5 of the packaging film 4 seen below the film removal device 8, 10 are a separating or cutting device 12 with a transverse arranged to the film knife and a welding device 14 with arranged on both sides of the film welding beam 14a, b arranged.

Below the cutting and welding devices 12, 14 is a vertically downwardly directed inlet region 18 of a film transport device 20, which operates in a transport direction 21 and consists essentially of two endless circulating conveyor elements in the form of conveyor belts 22, 24, which within a conveyor region begins with the inlet region 18 and ends with a discharge region 26, at least in places are pressed against each other. The film transport device transports the separated and unilaterally welded film section along the length, wherein a longitudinal direction of the film section coincides with the transport direction 21.

Fig. 7 schematically shows that the film transport device can not only consist of two conveyor elements, but that each conveyor element may be formed of two or more successive in the transport direction part conveyor elements that complement each other. For example, a first conveying element consist of two first part conveying elements 22.1, 22.2, which may for example be designed as conveyor belts or partial conveyor belts and facing a uniform second conveying element 24 in the form of a conveyor belt, wherein the packaging film 4 or a film section 7 between the pressed against each other conveyor - Part or conveying elements is received by friction.

In the illustrated embodiment, initially follows the inlet region 18, a horizontal conveyor region 28 in which the conveyor belts 22, 24 extend substantially horizontally. The horizontal conveying region 28 is adjoined by a vertical, upwardly extending conveying region 30, in the course of which the adjacent conveyor belts 22, 24 are deflected several times around horizontal deflecting rollers 32 in alternating directions which deviate slightly from the vertical, so that the conveyor belts 22, 24 possibly over one large part or the entire length of the vertical conveying portion 30 are pressed against each other.

The vertical conveyor section 30 is adjoined by a horizontal transfer section 34 which terminates with the vertically downwardly directed delivery section 26 within a hoist frame 36 of the device. The delivery area 26 with discharge end 26a is located above an opening station or film opening device 40 which has means for gripping and opening the film.

At two parallel deflection rollers 26b, the conveying elements are deflected and separated from each other, the so far transported therebetween foil section is released or discharged.

Fig. 4 shows that there are four gripping elements 40a in the form of surface suckers, with which a front wall 4a and a rear wall 4b of an end section of the film section 7 can each be grasped by two surface vacuums and opened in a tubular manner, wherein the initially folded side walls 4c of the tubular film unfold and forming an open film tube or end cap welded film cap which is picked up on a reefing device 44.

Below the film opening device 40 there is a vertically movable covering device 42, which in the illustrated embodiment has as a reefing device four reef bows 44 arranged in the corners of a square or rectangle for taking over and striking a film section 7. The overdrawing device 42 is located between an in Fig. 1 and 2 shown Überziehegangshöhe H up to a Überziehendhöhe h vertically movable to pull a separated film section over the stack 2.

The Überziehegangshöhe H is dimensioned so that good stacks 2 are processed with the greatest possible height of the device easily, while the Überziehendhöhe h just below a lower edge 2a of a stack 2, so that the film if necessary with "understretch", the lower edge 2a can be pulled over the pile.

The stack 2 itself is located on a conveyor 48 at a vertical distance F on a hall level 50 on which the device is arranged and are carried out from the work on the device, such as maintenance or repair work and replacement of the film roll. 6

To work on the feed rollers 10, the cutter 12 and the welder 14 and the replacement of the film roll 6 in a simple manner, for. B. by an operator who is on the hall level 50 to perform, said device elements should not be higher than, for example, 1.5 m above the hall level 50 to easily access it. The film roll 6 can be arranged higher, for example, up to 2 m or even higher, since it is not usually moved directly by an operator, but by means of a transport device, for example with a forklift.

Regardless of whether a hall level 50 is present as a "reference plane" for a favorable positioning of the discharge device and cutting and welding devices, it offers considerable advantages when said devices are below the Überziehegangshöhe H, conveniently within a film preparation area V, the extends from below the stall height h to at most 50% or 75% of the stall altitude H.

According to the invention, a device for neutralizing electrostatic charges of the packaging film 4 is arranged adjacent to the discharge end 26a of the film transport device 20, which in the illustrated embodiment comprises two rod-shaped ion generators 60 includes. The ion generators 60 are each arranged parallel and adjacent to a deflection roller 26b of the film transporting device 20 arranged at the delivery end 26a. As Fig. 5 shows, between the discharge end 26a of the film transport device 20 and the Reffeinrichtung 44 a film path 62 is formed, along which the film section 7 is opened and teased at approximately inverted V-shaped course of the front and rear walls 4a, b. The ion generators 60 are preferably located outside an inner region enclosed by the tubular film section, so that it is possible to apply ions to antistatic not only the film material but also the conveying elements which have just been separated from each other and therefore possibly particularly statically charged.

Each ion generator 60 has a number of ion nozzles distributed over its length, for example at least 5, 10, 20 or 30 individual ion nozzles directed towards the front and rear walls 4a, b of the opened film section 7. The ion generators 60 preferably have a length L which coincides with a width B of the opened film section 7 or with a width of the front wall and rear wall of the film section. Optionally, further ion generators can be arranged adjacent to the side walls 4c, which are transferred from their folded position into a substantially planar position arranged perpendicular to the front and rear wall when the film section 7 is opened. These additional ion generators may be shorter than the ion generators 60 associated with the front and rear walls and may protrude into an area located between two opposing gripping members 40a and below the lateral ends of the pulleys 26b to minimize the distance to them opening side walls 4c is achieved.

The ion jets of the ion generators 60 may be controllable to optimize the neutralization effect. The applied voltage and / or its pulse modulation and / or the air purge of the ion nozzles may be controllable in dependence on the charge intensity of the film portion and on the speed at which the film portion passes the ion generators.

LIST OF REFERENCE NUMBERS

2

stack

2a

lower edge

4

foil

4a

front wall

4b

rear wall

4c

Side wall

5

unwinding

6

Film roll (film stock)

7

film section

8th

deflecting

10

feed rollers

12

Cutting device (separating device)

14

welding equipment

14a, b

welding bars

18

intake area

20

Film transport means

21

transport means

22

first conveyor belt (conveyor element)

22.1, 22.2

first partial conveyor belt (partial conveying element)

24

second conveyor belt (conveying element)

26

delivery area

26a

delivery end

26b

idler pulley

28

horizontal conveying area

30

vertical conveyor area

32

guide rollers

34

Transfer area

36

lifting gear

40

Film opener

40a

gripping element

42

Pull-down device

44

Reffbügel (Reffeinrichtung)

48

Conveyor

50

exhibition hall

60

ion generator

62

film path

B

Width (from 4a, b)

H

Stall initial height

H

About Pulling height

F

Distance between 48 and 50

L

Length (from 60)

V

Film preparation area

Claims (11)

A method of wrapping an article (2) with a tubular packaging film (4), comprising the steps of: - Providing a supply (6) of tubular, flat folded packaging film (4), - removing the packaging film (4) from the supply (6) and transporting the packaging film (4) to an opening station (40), Separating a film section (7) required for a wrapping process, - Transporting the packaging film (4) before reaching the opening station (40) by frictional engagement between at least two mutually pressed, in a transport direction (21) moving endless circulating conveyor elements (22, 24), wherein the conveying elements (22,24) at a discharge end (26a) are deflected around two parallel deflection rollers (26b) and separated from each other, Opening the film section (7), - receiving the film section (7) on a Reffeinrichtung (44) and wrapping the article (2), wherein the film portion (7) is at least partially antistatic treated before and / or during opening and electrostatic charges on the packaging film (4) are at least partially neutralized by the packaging film (4) of rod-shaped ion generators (60) is treated antistatic, respectively parallel and adjacent to a at the discharge end (26a) arranged deflection roller (26b) are arranged. A method according to claim 1, characterized in that the ion generator (60) outside of the tubular film portion (7) enclosed inside area are arranged. Method according to claim 1 or 2, characterized in that the wrapping film (4) is stored and fed as a gusseted tube having a front wall (4a), a back wall (4b) and two side walls (4c) folded therebetween, wherein before and / or during When opened, the front wall (4a) and the rear wall (4b) are antistatically treated. A method according to claim 3, characterized in that after the start of the opening and the side walls (4c) are treated antistatic. Method according to one of the preceding claims, characterized in that the packaging film (4) after leaving the conveying elements (22, 24) is opened, wherein the front wall (4a) and the rear wall (4b) in the region of the conveying elements (22, 24) to each other lie and after leaving the conveying elements (22, 24) vice versa V-shaped opened and treated antistatic. Method according to one of the preceding claims, characterized in that the antistatic treatment comprises monitoring or detection of the electrostatic charge of the packaging film (4), ion generation by means of discharge electrodes and an air purge directed from the discharge electrodes to the packaging film (4). Method according to one of claims 5 to 7, characterized in that the conveying elements (22, 24) are continuously discharged during operation. Device for wrapping an article (2) with a tubular packaging film (4), comprising: - a supply (6) of tubular, flat folded packaging film (4), a withdrawal device for withdrawing the packaging film (4) from the supply (6), a separating device for separating a film section (7), - a film transport device (20) for transporting the packaging film to an opening device (40), wherein the opening device (40) comprises gripping elements (40a) for detecting the film section (7), wherein the film transport device (20) comprises a first endlessly circulating conveying element (22) and a second endlessly revolving conveying element (24) pressed against the first conveying element (22), which can be driven in a transporting direction (21) and between which the film section (7) can be received by frictional engagement between the separating device (12) and a dispensing end (26a) is a reefing means (44) for receiving the film section (7), - a coating device (42) for wrapping the article (2) with the film section (7), - A means (60) for neutralizing electrostatic charges on the packaging film (4), which at the discharge end (26a) of the film transport device (20), which is located at a distance above the opening means (40), and by two or more rod-shaped Ion generator (60) is formed, each parallel to and adjacent to one of two at the discharge end (26a) arranged parallel deflection rollers (26b) of the film transport device (20) are arranged. Apparatus according to claim 8, characterized in that the ion generator (60) outside of the tubular film section (7) enclosed inside area are arranged. Apparatus according to claim 8 or 9, characterized in that between the discharge end (26a) of the film transport device (20) and the Reffeinrichtung (44) a film path (62) is formed, along which the film section (7) is opened and teased, wherein the ion generator (60) is arranged at a distance of up to 300 mm, 150 mm or 50 mm from the film path (62). Device according to one of claims 8 to 10, characterized in that the first and / or the second conveying element (20, 22) is designed as at least partially electrically conductive transport belt.

Images