EP1088779B1 - Method for winding a material web - Google Patents

Description

The invention relates to a method for winding a Material web to a role in which the role in lies in a changing bed, by a loading roller the changing bed is pressed and at least during one Part of the winding process through a compressed air cushion is supported in the changing bed.

Such a method is known from US 5 758 842 A. A web of material is wound up into a roll, which is in a changing bed divided by two Carrier rollers is formed. The feed roller on the inlet side has a softer coating than the other carrier roller. The roll is loaded by a load roller, which lies on the winding reel at the start. In the changing bed can be built up a compressed air cushion to the Relieve some of the weight of the roll.

Another method of winding a web of material to a roll is known from US 4 128 213 A. Here are the two support rollers on which the winding roller rests with increasing diameter of the winding roll moved apart up to a maximum distance become. When this distance is reached the two support rollers moved together again. A load roller will roll with decreasing force pressed. The loading force lies in a final phase of the winding at about 0.1 kN / m.

DE 195 24 905 A1 shows a further method for winding a material web to a role in which the Roll lies in a changing bed. Can in the changing bed creates a compressed air cushion with the help of a blow box to partially reduce the weight of the roll relieve. With the help of a pressure roller is at the beginning a specific line force of approx. 25 N / cm set. If a predetermined diameter the roller is reached, the support rollers move apart and the platen is lifted off.

The invention is based on a paper web described as an example of a material web. she is however, not limited to this, but may be with others Material webs are used in which similar Problems like paper occur. Example of this are cardboard or foils made of metal or plastic.

In one of the last manufacturing steps, a paper web, which is usually produced "endlessly", too manageable rolls are wound up. In many cases the winding takes a slit into paper web strips ahead. When you wind up you want one achieve a certain course of winding hardness. The role namely should be wound harder inside than in the area of the scope. So the winding hardness should be from the inside remove to the outside.

The winding hardness is determined, among other things, by a nip force influenced, which is in the nip between the winding roll and sets the support rollers that form the changing bed. In a first approximation, one can assume that the higher the nip force, the higher the winding hardness is.

The desired winding hardness curve can be done without additional Practically not implement measures. At the start of the winding process, the role is practically only from the winding tube. So it's relatively light, like that that due to the nip force only one low winding hardness would result. With increasing Roll diameter also increases the weight of the roll and thus the nip force on the support nips, what the winding hardness would increase. It is therefore known to begin with of the winding process, a loading roller on the roll to let it rest, the load roller being the roller with a predetermined force in the changing bed. This allows the roll to be wound relatively hard, i.e. the winding hardness is in the area of the roll core or the winding tube high enough. Because with increasing Roll diameter the weight increases the load from the load roller increases recycled. Often, with the help of the pressure pad in the Changing bed acting in the opposite direction Strength built on the role. The burden of The load roller is withdrawn because it in turn lead to an increase in the nip force on the support nips would what is undesirable. The load roller is often only loose or under a relative kept low pressure of about 0.2 kN / m on the roll, to accidentally eject (kick-out) the roll prevented from the changing bed.

Despite all these measures, one can occasionally observe that the role is not built up like this is wanted in and of itself. Especially if a paper web or another web result in larger transverse or longitudinal profile deviations, the run of the roll can become very restless when winding, so you basically don't even get it can assume that the winding hardness curve over the entire Scope of the role is the same.

The invention has for its object the winding quality improve and make operations safer.

This task is carried out in a method of the type mentioned at the beginning Art solved in that the loading roller Roll with one during the entire winding process Presses a minimum load of 0.5 kN / m into the changing bed.

This measure seems contradictory in itself, because you go through the extra load that the load roller also applies the nip load in the Circulation nips increases, which in and of itself increases the winding hardness in the outer areas of the winding roll would lead. This effect is slight Dimensions available. Especially in the end section of the Winding process, for example in the last 40% of the Diameter, is caused by pinching the roll between the loading roller on the one hand and the changing bed on the other hand, a much smoother run is achieved. A "jumping" of the role and the associated strong unevenness in the winding hardness course largely avoided by the loading roller. in this connection it should be noted that the additional nip force that the Exercise roller exerts, based on the nip force that resulting from the roll weight, only of subordinate Meaning is. The "negative" effects, by increasing the nip force of the load roller are expected to be on the role by the "positive" effects of these increases at least compensated.

It is preferred that the compressed air cushion depending controlled by the load on the load roller becomes. When the load on the load roller is increased, then the pressure in the compressed air cushion also increased so that the nip force in the Supporting nips on the support rollers forming the changing bed can limit. There is a certain automatism here. The compressed air cushion is, if necessary, under Consideration of other conditions, such as a minimum roll diameter, immediately to the burden of coupled the loading roller. Since this at least starts a predetermined roll diameter with a constant Force acts, one can have a correspondingly constant Generate counterforce using the compressed air cushion. Because the corresponding forces overlap linearly control is very easy.

Preferably, the load roller is used to the Determine the diameter of the roll, using the compressed air cushion depending on predeterminable parameters the wound material web and the diameter of the Role is controlled. If the load roller on the circumference of the roller, then the location of the load roller information about the diameter of the Role. This diameter information allows under Consideration of the parameters of the material web, for example Weight per unit area or density, based on weight and conclude the associated weight of the role. Then from the weight deduce the nip force in the support nips of the roll. So if, for example, not only their strength, but also passes on their location to a controller, then the controller can use the air cushion relatively adjust exactly.

The compressed air cushion is preferably set such that that a predetermined maximum nip force between the Role and the support rollers forming the changing bed is exceeded. This limits the winding hardness.

The maximum nip force is preferably dependent of paper grade sensitivity in the range of 2 to 5 kN / m. This value has proven to be sufficient to produce the desired winding hardness, on the other hand but to protect the material web sufficiently.

In a preferred embodiment it is provided that a nip force curve between the roller and the support roller the entire winding process remains approximately constant. Despite the load from the load roller remains the resulting nip force, which is also taking into account the weight relief with the help of the compressed air cushion results, approximately constant. With this term is meant that certain variations are perfectly acceptable could be. However, the changes remain below 25% of an average nip force curve. Around to be able to set a winding hardness curve, where the winding hardness decreases from the inside to the outside, you can take further measures. for example set the drive torques of the support rollers differently.

Because of the configuration according to the invention, it is now possible to watch the roll while winding and the load on the load roller increases when there is an uneasy run. The restless run can visually determined by an operator. you can also make vibration measurements and depending on the frequency or amplitude of the vibrations increase the force of the load roller. By this possibility of feedback allows the winding quality of the role continue to improve. Because that through that Compressed air cushion automatically generates counterforce Force of the load roller is adjusted, result despite a "firmer" hold of the roll in the winding bed no significant changes in winding hardness.

The compressed air cushion is only advantageous from one predetermined roll diameter turned on, wherein this roll diameter with the load from the Loading roller is changed. With this approach one takes into account the fact that only from one predetermined roll weight actually relieves compressed air is necessary because only from a certain Roll diameter the roll weight so far increases that the nip force in the support nips increases the hardness could negatively affect. By increasing the force of the load roller can now to shift the circumstances. If, for example, due to a troubled run of the role an increase in the The force of the load roller is necessary, the sum then one from load and weight assumed critical value if the otherwise usual Roll diameter has not yet been reached. In this In this case, the compressed air cushion is set up earlier.

Fig. 1

eine schematische Seitenansicht einer Wickelvorrichtung und

Fig. 2

verschiedene Kurven zur Darstellung des Wikkelverfahrens.

The invention is described below with reference to a preferred embodiment in connection with the drawing. Show here:

Fig. 1

is a schematic side view of a winding device and

Fig. 2

different curves to represent the winding process.

Fig. 1 shows a winding device for winding a Material web 2 to a winding roll 6 '. The web of material 2 is wound onto a sleeve 6, which rests in a changing bed 11 by two Carrier rollers 3, 5 is formed. The changing bed 11 will with the help of a blow box 4, which is in the gusset below the support rollers 3, 5 are arranged, supplied with compressed air, i.e. A compressed air cushion can be controlled in the winding bed 11 be built to support the Serves winding roller 6 'and thus the bearing force of the Winding roll 6 'on the support rollers 3, 5 reduced.

Above the winding bed 11 is a loading roller 7 arranged by means of a motor 8, the present Case designed as a piston-cylinder engine is, via a linkage 9 in the direction of the changing bed can be charged. As a result, the sleeve 6 and later the winding roll 6 'is pressed into the winding bed 11, So against the support rollers 3, 5. With increasing The diameter of the winding roller 6 'moves the loading roller 7 up. For a larger diameter the winding roll 6 ', which is shown in broken lines, the position of the winding roller 7 is also dashed located.

The angular position, i.e. an angle α, of the linkage 9 opposite A pivot point 13 is with the help of a sensor 12 recorded. Since the length of the lever linkage 9 is known is the position of the loading roller from the angle α 7 determine relative to the changing bed 11. This Location information can also be obtained in other ways , for example from the extension movement the engine 8. Finally, it is not necessary that the loading roller moves over a lever linkage 9 becomes. It is also conceivable that the loading roller 7 in a linear guide is arranged.

The position information of the sensor 12 becomes one Control device supplied. The control device controls a force F via the motor 8 with which the loading roller 7 acts on the winding roll 6 '. How to continue explained below is the force of the load roller depending on the diameter of the winding roll 6 '. therefore are two different forces F, F 'in Fig. 1 indicated that at different diameters of the Winding roll 6 'or the sleeve 6 from the loading roller 7 are applied. The control device also controls 10 also the pressure of the blow box 4, i.e. the Air pressure in the changing bed 11.

In Fig. 2 some curves are now shown, based on whose invention is to be explained. Here is a diameter D of the winding roll from left to right 6 'in mm. From bottom to top there is one Line load F plotted in kN / m. With a curve 14 shows the line load, which increases with increasing Diameter of the winding roll 6 'without additional Measures would result. The negative line load results from the fact that at the beginning of the winding process where the winding roll 6 'is still relatively light, the web 2 in the case of their entry via the support roller 3, the tendency has to lift the sleeve 6 out of the winding bed 11. For this reason, the load roller exercises in this area 7 a relatively large force. That power the loading roller is plotted in a curve 15. Finally, the force can be seen with a curve 16, with which the compressed air relief in the changing bed 11 is working. This force is in a relatively large range of the winding process is zero. You sit here only with a diameter of about 950 to 1000 mm on. From the sum of those acting on the winding roll 6 ' Forces results in a curve 17. This falls at the beginning then remains essentially constant and increases finally slightly. In the sense of the present The invention is intended to be a course as shown in curve 17 is referred to as "approximately constant". Changes compared to an average of ± 25% are quite permissible here.

At the beginning of the winding process, as I said, the loading roller 7 with a relatively high force F in Winding bed 11 directed so that the winding tube 6 and the winding roll 6 'formed thereon with a relative high nip force or nip load is wrapped. This creates a relatively high winding hardness at the beginning of the winding process. As the diameter increases Winding roll between the nip force in the support nips the winding roller 6 'and the support rollers 3, 5 due to Up to now, the dead weight of the winding roll 6 'has increased the load by the load roller 7 continuously retracted until the load from the load roller 7 was practically barely noticeable. usual The values were 0.2 kN / m. This burden F 'only served the winding roller 6' on it to prevent thrown out of the changing bed 3, 5 too become. Here it was assumed that too much load from the load roller 7 negatively affect the winding hardness of the winding roll 6 ' effect. This consideration is correct in and of itself. But one can observe that the winding hardness course is still unsatisfactory with some winding rolls.

Experiments have shown that the winding hardness is unsatisfactory can be observed especially when the run of the winding roller 6 'is very restless. The role jumps and vibrates in such cases, i.e. a reliable and reproducible determination of the Wrapping nip forces is basically practical not possible. A restless or uneven course can have many causes. For example, fluctuations in thickness are possible the incoming material web 2, the in the manufacture of, for example, a paper web not always avoid. Especially at higher ones Winding speeds make vibrations noticeable in the bearing of the support rollers 3, 5, which itself can also influence each other.

The considerations according to the invention now went to calm the run of the winding roller 6 'again. For this then you have the load from the loading roller 7th during the entire winding process always at least 0.5 kN / m kept. This is in the right half 2 from about 1035 mm roll diameter. The hatched area indicates that the load from the load roller in this The range can also be higher if required is.

So there is no negative influence due to the higher load the winding hardness occurs increases the control device 10 the pressure in the changing bed 11 accordingly. This can be seen from curve 16. Here too indicated by a hatched area that the Pressure in the changing bed depends on the load through the loading roller 7. The control is here relatively easy to implement because the force F, F 'of the loading roller 7 of the weight of the winding roll 6 'linearly superimposed. Accordingly, one can also to control the pressure in the changing bed 11 Principle of superimposing constant and variable Use press.

You can now the control device 10 the corresponding Forces F, F 'of the loading roller 7 and the associated Pressures in the changing bed 11 depending on parameters the material web, in particular basis weight or density. But you can also get one Provide actuator 18, with the help of an operator increase the pressure on the load roller can, if it turns out during the winding that the restlessness exceeds a tolerable level. Assessing this Question can either be visual by an operator take place or on the basis of vibration measurements the support rollers 3, 5 or the loading roller 7 made become. To the same extent as with the help of Actuating device 18 the load on the loading roller 7 is increased, of course, the pressure in the changing bed 11 increased.

The pressure in the changing bed 11 should depend on the paper type and its sensitivity be that the nip force in the support nips between the winding roller 6 'and the two support rollers 3, 5 is about 2 to 5 kN / m.

With the procedure according to the invention it is achieved that the web roll 6 'with the help of the loading roller 7 is pressed firmly into the changing bed on the one hand, to the desired high at the beginning of the winding process Generate winding hardness and at the same time eject it (Kick-out) the web of material from the To prevent changing bed. This holding or clamping function is maintained throughout the winding process. On the other hand, the control prevents that the bearing force of the web roll 6 'on the Carrier rollers 3, 5 becomes so large that damage occurs. The control allows it, even with considerably larger ones Forces to work on the load roller 7, because the Compressed air relief for a correspondingly controlled Compensation provides.

Claims (8)

1. Method for winding a material web (2) to form a reel (6, 6'), in which the reel (6, 6') lies in a winding bed (11), is pressed into the winding bed (11) by a loading roll (7) and, at least during part of the winding operation, is supported in the winding bed (11) by a compressed air pad, characterized in that the loading roll (7) presses the reel (6, 6') into the winding bed (11) with a minimum loading of 0.5 kN/m during the entire winding operation.
2. Method according to Claim 1, characterized in that the compressed air pad is controlled as a function of the loading of the loading roll (7).
3. Method according to Claim 1 or 2, characterized in that the loading roll (7) is used to determine the diameter of the reel (6, 6'), the compressed air pad being controlled as a function of pre-definable parameters of the material web (2) wound up and of the diameter of the reel (6, 6').
4. Method according to one of Claims 1 to 3, characterized in that the compressed air pad is set in such a way that a predetermined maximum nip force between the reel (6, 6') and the carrier rolls (3, 5) forming the winding bed (11) is not exceeded.
5. Method according to Claim 4, characterized in that the maximum nip force lies in the range from 2 to 5 kN/m, depending on the sensitivity of the grade of paper.
6. Method according to one of Claims 1 to 5, characterized in that a nip force profile between reel (6, 6') and carrier roll (3, 5) remains approximately constant over the entire winding operation.
7. Method according to one of Claims 1 to 6, characterized in that the reel (6, 6') is observed during winding and the loading by the loading roll (7) is increased if disturbed running is manifested.
8. Method according to one of Claims 1 to 7, characterized in that the compressed air pad is switched on only beginning at a predetermined reel diameter, this reel diameter being changed with the loading by the loading roll (7).

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