EP1688379B1 - Method and device for unwinding a material web from a material roll - Google Patents

Description

The invention relates to a method for unwinding a web of material web roll, in which one detects a web start of the material web and moves away from the web roll, wherein the web start generated by at least the outer layer of the material web in the direction of gravity severed at least the outer layer of the web and the removed on the web roll separated remainder of the web removed, wherein the web roll to remove the separated remainder is rotated until the rest of the web roll slides down.

Furthermore, the invention relates to a device for unwinding a material web from a material web roll with a bearing device in which the web roll is rotatably mounted, wherein in the direction of gravity in a region below the bearing means a cross-cutting device is arranged, with at least the outer layer of wound on the web roll Material web in the direction of gravity lower third is severed, wherein the bearing means comprises a roller drive, with which the web roll opposite to its winding direction is rotatable.

The invention will be described below with reference to a paper web as an example of the material web. However, it is also applicable to other webs that can be handled in a similar manner.

A paper web is produced almost endlessly in a paper machine. At the output of the paper machine, this paper web is wound onto a relatively stable roll core, the so-called drum, to form a web roll. Such material web rolls or Volltamboure can initially be stored. They can then be fed to a processing station for the paper web and placed there in an unwinding station. The processing station can be, for example, calenders set up offline, coating machines, winder or the like. In any case, the paper web must be unwound from the roll of web material to pass through the treatment device. The paper web is calendered in a calender. In a coater, a line is applied. In a slitter, the paper web is cut in the longitudinal direction and wound up the resulting partial webs to partial web rolls.

In order to make a transport of the full-length reels possible, the paper web with so-called riders, so short adhesive tapes, secured to the spool, i. the end of the paper web is glued to the circumference of the web roll. If the paper web is to be further processed, then the Volltambour is inserted into the unwinding device. The riders must then be manually removed by an operator. Thereafter, the spool is rotated so that the beginning of the paper web can be detected and passed through the processing station.

In EP-A1-1340702 a device for unwinding a material web from a web roll is presented, which is adapted to detect a web start of the web and move away from the web roll. The device looks to the Generating the web start a separator before, which can be effective in the lower part of the web.

Attempts have also been made to have the web start detected directly by the unwinding device. If the machine has determined where the web start is, then it can take this web start and thereby tear off the riders. For this purpose, however, a complex and expensive sensor is required, which detects the web beginning or the rider. In addition, occasionally when tearing off the rider to problems, in particular to relatively far-reaching longitudinal cracks, which complicate the further handling of the paper web.

The invention has for its object to enable a web insertion without or with little intervention of an operator.

This object is achieved in a method of the type mentioned in that one determines the rotation angle and uses it in combination with the position of the cutting to determine the position of the web start.

With this procedure, the position of the web beginning after severing the at least outer layer of the material web is always fixed. The beginning of the web is initially where the outer layer or optionally also several outer layers of the web roll have been severed. The severing takes place at a position which ensures that the forces on both sides of the dividing line are largely balanced. A nearly absolute balance is obtained when the cutting takes place at the lowest point of the web roll, in a view from the front side so in the "6 o'clock position". The severed web web layers then have practically the same weight on both sides of the crest of the roll of web material, so that only a relatively small train is applied to the outer layers of the winding roll during cutting. Even if the cutting is not carried out at the absolute lowest point, the train on both sides of the dividing line is relatively low, because the outer layers of the material web lie with a certain friction on the material web layers lying further inside. As a result of the cutting, the machine "knows" where the beginning of the web of material is to be found. To remove the separated remainder, on which the riders are located, you twist the web roll until the rest of the web roll slides down. This can be the removal of the rest of the web, which is still on the web roll, automate. A turning of the roll of web material can be realized relatively easily. In this case, according to the invention, the angle of rotation is determined and used in combination with the position of severing to determine the position of the web start. If you twist the web roll, then of course the position of the web start changes. The web start moves together with the remaining circumference of the web roll by the corresponding angle of rotation. But since you can include this angle of rotation in the investigation, the information about the position of the web start remains. It may be advisable to hold the web start when the rest of the web slides off the web roll.

Preferably, the web roll is turned back by a predetermined amount so far that the web start hangs freely downwards over a predetermined distance. This makes it easier to detect the web start.

Preferably, the web roll with its apex is rotated counter to the withdrawal direction. The withdrawal direction is not to be understood here as the direction of rotation of the web roll when unwinding, but as a page. If the material web is pulled off to the right, then you twist the web roll so that its apex, so seen in the direction of gravity top point, moves to the left. This applies regardless of whether the material web is pulled in this situation from above or from below of the web roll. If you set the direction of rotation to remove the separated remainder in this way, then you only need a pulper opening. This is then arranged in a place where enough space is available. The pulper opening thus does not prevent further operation.

For cutting through, it is preferred to use a transverse cutting device which is guided in a guide running parallel to the axis of the web roll. This results in a dividing line and thus a web beginning, which runs at right angles to the longitudinal direction of the material web. This facilitates further handling.

In this case, it is particularly preferred that a cross-cutting device is used with a surface sensor and a separating element which protrudes a predetermined distance over the surface of the material web roll determined by the surface sensor. The separator is thus able to penetrate slightly into the surface of the web roll and thus sever the outermost layer or multiple outer layers of the web. Conveniently, one will set the predetermined distance to the thickness of the web or a multiple of the thickness of the web.

In a device of the type mentioned, the object is achieved in that in the direction of gravity in a region below the bearing means a cross-cutting device is arranged, with the at least the outer layer of wound on the web roll material web in the direction of gravity lower third is severable. As described above in connection with the method, the cross-cutting device is able to sever the material web, which is still wound on the web roll in the direction of gravity below. The outer layers of the web that have been severed then hang down on both sides of the web roll. This results in the severing of the web only relatively low tensile forces acting on the outer layers of the web. The risk that the web breaks uncontrollably, so is kept relatively small. The position of the web start is then determined by the position of the cross-cutting device, so that the device, based on this information, can automatically detect the web start.

Preferably, the bearing device has a roller drive with which the web roll is rotatable counter to its winding direction. The roller drive can then be used to remove the separated on the web roll separated remainder of the web. If the web roll has been rotated counter to its winding direction by a sufficient angle, then the separated remainder of the web automatically slides down.

Preferably, a rotation angle sensor is provided which detects the rotation of the web roll. The rotation angle sensor thus ensures that it does not lose information about the position of the web start, but is maintained.

Preferably, a pulper opening is arranged on the side of the web roll opposite the take-off side. In this Pulperöffnung then falls the separated remainder of the web automatically when the web roll has been rotated against its winding direction. This facilitates the disposal of the rest.

Preferably, the cross-cutting device is guided in a direction parallel to the axis of the web roll guide. This can be relatively parallel to generate the dividing line parallel to the axis of the web roll. The web start then forms a line which runs transversely to the longitudinal direction of the material web. Such a guide also makes it easier to keep the cross-cutting device always in the same orientation to the web roll.

Preferably, the cross-cutting device comprises a surface sensor which detects the position of the surface of the material web roll, and a separating element, which can be positioned by a drive so that it dips over a predetermined distance in the surface of the web roll. The predetermined distance is set, for example, to the thickness of the material web. The surface sensor detects the surface of the web roll. This provides the information about the position of the surface. If you let now dipping the separator to the material web thickness in this surface, then exactly one layer of the material web is severed. If one chooses the predetermined distance to a multiple of the material web thickness, then a corresponding multiple of material web layers is severed. It can therefore achieve a relatively accurately adjusted cross-cutting.

The separating element preferably has a rotating knife. The outer layer or the outer layers of the material web are therefore cut open.

Alternatively, the separator may have a wedge. The wedge enters the end face of the web roll and then tears open the outer layer or the outer layers of the material web.

Preferably, the bearing device and the cross-cutting device are arranged in a preparation position of the device. Thus you can already make the preparation of unwinding the web roll when another web roll is unwound.

• Fig. 1 eine Materialbahnrolle in einer Abwickelvorrichtung vor dem Vorbereiten,
• Fig. 2 die Materialbahnrolle in einem ersten Verfahrensschritt des Vorbereitens des Abwickelns,
• Fig. 3 die Materialbahnrolle in einem zweiten Verfahrensschritt des Vorbereitens des Abwickelns,
• Fig. 4 die Materialbahnrolle in einem dritten Verfahrensschritt des Vorbereitens des Abwickelns,
• Fig. 5 die Materialbahnrolle beim Abwickeln und
• Fig. 6 eine schematische Darstellung einer Trenneinrichtung.
• Fig. 1 zeigt eine Vorrichtung 1 zum Abwickeln einer Materialbahn 2 (Fig. 4 und 5) von einer Materialbahnrolle 3. Die Materialbahnrolle 3 ist als sogenannte "Mutterrolle" oder "Volltambour" ausgebildet, d.h. auf einen stabilen Rollenkern 4 ist eine große Anzahl von einzelnen Lagen der Materialbahn 2 aufgewickelt. Ein derartiges Aufwickeln erfolgt beispielsweise am Ende einer Papiermaschine.

The invention will be described below with reference to a preferred embodiment in conjunction with the drawings. Herein show:

• Fig. 1 a web roll in an unwind prior to preparing,
• Fig. 2 the web roll in a first step of preparing the unwinding,
• Fig. 3 the material web roll in a second process step of preparing the unwinding,
• Fig. 4 the material web roll in a third process step of preparing the unwinding,
• Fig. 5 the web roll when unwinding and
• Fig. 6 a schematic representation of a separator.
• Fig. 1 shows a device 1 for unwinding a material web 2 (FIG. 4 and 5 ) of a web roll 3. The web roll 3 is as So-called "mother roll" or "full tambour" formed, ie, a large number of individual layers of the material web 2 is wound on a stable roll core 4. Such winding takes place, for example, at the end of a paper machine.

The material web roll 3 lies with its roll core 4 in a storage device 5, in which it can be rotated. This bearing device 5 may be the bearing device, which is later used for unwinding the material web 2 from the material web roll 3. However, it may also be a storage device in a preparation position, in which the material web roll 3 is prepared only for further unwinding.

The end of the material web 2 is defined by so-called tabs 6, which are generally formed by short adhesive strips which extend in the circumferential direction, on the circumference of the web roll 3. Such a determination is necessary so that the web roll 3 can be transported at all from the winding station to the unwinding device 1. So far, these tabs 6 were manually removed to the end of the web 2, which then forms the beginning of the unwinding capture and by a downstream and in Fig. 1 leading not shown treatment station. Such a treatment station may be, for example, a calender, a coater, a slitter or the like. However, this preparation is virtually impossible to automate.

In order to automate the detection of the web start, the device 1 is now provided with some additional elements.

On the one hand, a cross-cutting device 7 is arranged below the bearing device 5. The cross-cutting device 7 has a knife 8, the in a guide 9 along the axial length of the web roll 3 can be performed, as described below in connection with Fig. 6 is described. The knife 8 is able to sever the outer layer or several outer layers of the web roll 3 during this displacement.

Furthermore, the bearing device 5 has a drive 10 with which the material web roll 3 can be rotated. This drive 10 may be relatively weak, because he has to turn the web roll 3 only slowly and to a small extent.

Finally, a rotation angle sensor 11 is also provided in the region of the bearing device, which detects the angle of rotation by which the material web roll 3 is rotated. This rotation angle sensor 11 can cooperate, for example, with not shown markers on the roll core 4. The entire storage device 5 is arranged on a machine-fixed frame 12, which is shown only schematically.

It is now assumed that the web is to be pulled off to the right. Accordingly, a pulper opening 13 is provided at the left end of the web roll 3, which leads to a pulper, not shown. The pulper opening 13 may have an elevated left side wall 14 to facilitate "catching" of the outer layers of the web roll 3, as will be described below. Shown is an operating mode in which the material web is pulled off from above. In this case, the web roll 3 rotates clockwise. In a corresponding manner, the material web can of course be removed from below from the web roll 3. In this case, the web roll rotates counterclockwise. In both cases, the deduction direction is here to the right.

In the following Fig. 2 to 6 the same elements are each provided with the same reference numerals.

In Fig. 2 a situation is shown in which the knife 8 has been moved over the entire axial length of the web roll 3. The knife 8 has severed the outer layers. This has two effects. On the one hand, the two ends 15, 16 of the layers hang down freely from the two sides of the material web roll 3. In order to simplify the following explanation, the right side of the material web roll 3, from which the material web 2 is to be removed later, is referred to as the front side and the opposite side as the back side. The riders 6 have remained unchanged in their position. As a further consequence, the severing of the outer layers has the consequence that a web start is formed at a position indicated by an arrow 17. This web start 18 depends together with the front end 16 of the outer layers down. Of course it is also possible to cut through only one outer layer.

The rear end 15 of the outer layers also hangs down and protrudes into the pulper opening 13. Since after cutting the outer layers, the rear end tends to overshoot, the raised side wall 14 is provided, which ensures that the rear end 15 actually hits the pulper opening 13. Of course you can also provide a pulper opening on the front side. This is not shown here. An additional opening, however, increases the cost. It is also possible to provide the pulper opening not at the rear end, but at the front end. However, the arrangement of the pulper opening 13 at the rear end has the advantage that it disturbs less here.

In Fig. 3 now the next step is planned. The drive 10 rotates the material web roll 3 counter to its withdrawal direction, ie in the direction of an arrow 19. The rear end 15 of the outer layers passes further into the pulper. Eventually, then, the free hanging weight of the rear end 15 will be so large that the entire separated outer layers from the periphery of the web roll 3 slide down and fall into the pulper opening 13. The angle of rotation required for this depends, among other things, on how smooth the material web is, ie, what frictional resistance the outer layers have on the circumference of the material web roll 3. The angle of rotation by which the material web roll 3 is rotated is determined by means of the rotation angle sensor 11. Since the position of the knife 8, the original position of the web start 18 is known, the current position of the web start 18 is now known with the help of the determined by the rotation angle sensor 11 data on the rotation angle.

In Fig. 4 Now, the web roll 3 has been rotated back in the direction of arrow 20, so that the web 2 from the front end of the web roll 3 hanging freely. The rotation angle has been detected again via the rotation angle sensor. The rotation is performed by the drive 10. This makes it possible to determine the position of the web start 18 relatively accurately. A gripping device 21 shown only schematically can detect the web beginning and the material web 2, as in Fig. 5 is shown, lead through a web treatment device 22 shown only schematically.

As soon as the material web roll 3 is rotated, the knife 8 is lifted off the circumference of the material web roll 3.

Fig. 6 now shows the cross-cutting device 7 from the side. The cross-cutting device 7 has, as a separating element, the knife 8, the here is designed as a rotating circular blade. The knife 8 is attached to a lever 23 which is pivotable on a carriage 24. The carriage 24 is movable on a linear guide 25 parallel to the axis 26 of the material web roll 3.

The lever 23 is pivoted by a drive 27, for example a pneumatic cylinder, in the direction of the material web roll 3. A surface sensor 28 is provided to determine the position of the surface 29 of the web roll 3. The drive 27 is now operated in response to the signal from the surface sensor 28 so that the knife 8 penetrates by a predetermined distance in the surface. This distance corresponds to the thickness of the material web 2 or, if several material web layers are to be severed, a multiple of this thickness. This cutting depth can be set relatively accurately.

Of course, instead of the knife, it is also possible to use a wedge which detects one or a few material web layers from the end face of the material web roll 3 and tears it open. Also in this way one obtains a transverse cutting line, which then later defines the web start 18.

Shown is an embodiment in which the cross-cutting device 7 is arranged at the lowest point of the material web roll 3. This has the advantage that immediately after the separation substantially equilibrium between the front end 15 and the rear end 16 of the separated material web layers exists. This in turn has the consequence that when cutting virtually no weight-related train on the two ends 15, 16 is exercised. The separation can therefore be largely unaffected by external forces on the material web layers. Due to the fact that the material web layer or the material web layers but with a certain friction on the lower-lying peripheral layers of Material web roll 3 rest, you can change the position of the cross-cutting device 7 also. In general, it will be sufficient to position them in the lower third of the web roll 3 (with respect to the direction of gravity).

Claims (12)

1. Method for unwinding a material web from a material-web reel, in which method a web start of the material web is detected and moved away from the material-web reel, the web start being produced by at least the outer layer of the material web being severed in the lower third in the direction of gravity and the severed rest of the material web which lies on the material-web reel being removed, the material-web reel being rotated in order to remove the severed rest, until the rest slides from the material-web reel, characterized in that the rotary angle is determined and it is used in combination with the position of the severing in order to determine the position of the web start.
2. Method according to Claim 1, characterized in that the material-web reel is rotated backward by a predefined amount, to such an extent that the web start hangs freely downwards over a predefined distance.
3. Method according to one of the preceding claims, characterized in that the material-web reel is rotated with its crown counter to the drawing-off direction.
4. Method according to one of Claims 1 to 3, characterized in that a transverse cutting device is used for severing, which transverse cutting device is guided in a guide which extends parallel to the axis of the material-web reel.
5. Method according to Claim 4, characterized in that a transverse cutting element is used with a surface sensor and a cutting element which protrudes a predefined distance beyond that surface of the material-web reel which is determined by the surface sensor.
6. Apparatus for unwinding a material web from a material-web reel having a bearing device, in which the material-web reel is mounted rotatably, a transverse cutting device (7) being arranged in the direction of gravity in a region below the bearing device (5), with which transverse cutting device (7) at least the outer layer of the material web (2) which is wound up on the material-web reel (3) can be severed in the lower third in the direction of gravity, the bearing device (5) having a roller drive (10), by way of which the material-web reel (3) can be rotated counter to its winding direction, characterized in that a rotary angle sensor (11) is provided which detects the rotation of the material-web reel (3).
7. Apparatus according to Claim 6, characterized in that a pulper opening (13) is arranged on that side of the material-web reel (3) which lies opposite the drawing-off side.
8. Apparatus according to either of Claims 6 and 7, characterized in that the transverse cutting device (7) is guided in a guide (25) which extends parallel to the axis (26) of the material-web reel (3).
9. Apparatus according to one of Claims 6 to 8, characterized in that the transverse cutting device (7) has a surface sensor (28) which determines the position of the surface (29) of the material-web reel (3) and a cutting element (8) which can be positioned by a drive (27) in such a way that it dips into the surface (29) of the material-web reel (3) over a predefined distance.
10. Apparatus according to Claim 9, characterized in that the cutting element (8) has a rotating knife.
11. Apparatus according to Claim 9, characterized in that the cutting element (8) has a wedge.
12. Apparatus according to one of Claims 6 to 11, characterized in that the bearing device (5) and the transverse cutting device (7) are arranged in a preparation position of the apparatus (1).

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