EP1080267B1 - Method for calendering a line of a product with a vertical multi-roll calender, and corresponding calender - Google Patents

Description

The invention relates to a method for calendering a web with a vertical multi-roll calender according to the preamble of the claim 1 and a calender for this.

Vertical multi-roll calenders include one set of rolls superimposed rollers, which in the operating state in constant Are interacting, and through their nips, one web to be calendered runs.

As from the weekly paper for paper manufacture 121, 1993, pp. 29 to 33 known, calendering causes a mechanical or mechanical-thermal Forming the web. To optimize this transformation, in particular a paper web, different roller types in one Combined roller package. In the top and bottom positions are preferred Bending adjustment rollers are used, and the ones arranged between them Intermediate rolls are designed as hard rolls and elastic rolls. Hard rolls are metal rolls with a smooth one and hard roller, which is essentially responsible for the smoothness and gloss are. Soft rolls are rolls with an elastic one or soft surface, which is essentially for a uniform Ensure compaction.

Due to the weight of the rollers and the guide means connected to them, such as guide rolls, roll journals and bearing housings, the compressive stress increases in the nips from top to bottom. The highest line load prevails in the bottom nip. These are assigned to a set of rollers The increase in line load results in the characteristic, almost linear natural line load characteristic.

One problem, however, is that because of the low line load only a small proportion of the deformation in the upper columns is provided. A load on the roller pack from the upper end increases the usable line load range, but without influence take on the line load increase in the roll package, i.e. the slope the natural characteristic remains unchanged. Since the bottom nip prevailing line load cannot be chosen arbitrarily large for wide calenders with high dead weights of the rolls and flatter Line load characteristic severely limits the usable line load range.

As is known from US-A-3,060,843, by compensating the overhanging weights, in which the own weights of the guide means are eliminated be, so that practically straight, bend-free intermediate rolls and accordingly straight, horizontal nips result in a steeper Line load characteristic can be obtained. With the same line load in the bottom nip is the line load in the upper part of the calender elevated.

To keep the effective roller weights small, DE 295 21 610 U1 known to tilt the effective plane of the roll stack to the vertical. As a result, only the vertical component of the weight goes in the increase in line load. The line load increase is consequently reduced, but firmly assigned to the roller set.

Other proposals aim to reduce the weight of the rollers. For this purpose, rollers with the smallest possible diameter or used in a lightweight construction. A calender roll with one thin cladding and an inner supporting cell structure is in DE-A- 195 11 595. A similar concept is the roller according to DE-A-195 33 823. A reduced increase in line load in this way but is in turn assigned to the set of rollers. A line load specification is only in either an upper or a lower nip possible. The other line load results from the dead weight.

Finally, from WO 95/14813 is a vertical multi-roll calender known with a bend-controllable top and bottom roller and intermediate rollers, in which the intermediate rolls are selected so that they are all one have essentially the same natural deflection. Through a complete lifting or compensation of the weights of the intermediate rolls together Guiding means is achieved that these weights have no influence on the line load in the nips. This means that the line loads are the same in the bottom nip and top nip, with the same inherent deflections of the intermediate rolls ensure essentially flat line load profiles. With a selectable load on the top or bottom roller then the line loads in the nips are adjusted. The disadvantage here is that only intermediate rolls with the same inherent deflection can be used are. There is also some difference in line load from one nip to another nip desirable to maintain a web tension between to build up two nips for a wrinkle-free running of the material web is necessary.

The object of the invention is therefore a method for calendering a To create a web with a vertical multi-roll calender, one Adjustment of the line loads in the nips to a web to be calendered allowed. Another job is a calender to create for this.

These objects are solved by the features of claims 1 and 11, respectively.

This creates a method that the design-related changed natural or compensated line load characteristic of a calender, around a multi-roll calender optimally on a web, in particular a type of paper. Different from the natural or compensated characteristic curve depending on the flatter or steeper characteristics are set for the web to be calendered, setting a negative slope, i.e. in the the top nip has a higher line load than the bottom nip, is possible.

To ensure that the line load distributions are uniform between the intermediate rolls, all intermediate rolls must be one experience essentially the same deflection, i.e. same bending lines exhibit.

Through a targeted bending of the intermediate rolls, which leads to relief or loading the own weights of the rollers, the gradient of the Line load characteristic and thus the line load difference between the top and lower nip can be set freely. The calendering potential of a such a calender is therefore not fixed by construction specified, but can be on the respective web during operation can be set. In addition, the nip number can be below that in the super calender can be reduced and good smoothing effects even at high Speeds can be realized.

The variable setting of the line load characteristic is also still when using rollers with different roller diameters possible in a roller set. As is well known, smaller roll diameters result a smaller gap width resulting in a higher compressive stress. Because the compressive stress and not the line load the mechanical Size that is essentially responsible for the reshaping can be influenced via the roller diameter on the load. The steep due to the smaller roller diameter Line load characteristic can be changed by the method according to the invention without losing the advantage of a smaller gap width.

Furthermore, it is not necessary to construct the intermediate rolls in this way train that their deflections from their own weight and their bending stiffness are equal to each other.

If a roll set consists of intermediate rolls of different bending stiffness, so the amount of deformation force depending on the respective bending stiffness can be selected. This leads to different Line load differences from intermediate roll to intermediate roll or from nip to nip, but ensures the same deflections.

To set a desired line load characteristic, line loads, that prevail during calendering in the upper and lower nip should be specified independently of each other. Associated mean Line loads can be caused by the loading or unloading pressures of the intermediate rolls be determined. The starting point for this are preferably those of overhanging weights and from the deflection and spreader rollers fully relieved intermediate rolls, so that all rolls straight nips form. In this respect, one speaks of a compensated roll stack a compensated line load characteristic. This compensated line load characteristic preferably serves as a reference characteristic.

Starting from this reference characteristic curve, the intermediate rolls can be loaded or be relieved that the sum of all intermediate rolls the desired line load difference between the upper and lower Nip results and the desired changed characteristic is created.

For a calculation of target values for the deformation forces, the Beam bending of the intermediate rolls can be used. For a more refined The shear deformations, a shell bending and / or can be adjusted a shell shear deformation is included in a calculation of the target values become.

Further refinements and advantages of the invention are the subclaims and the following description.

Fig. 1

zeigt schematisch die Seitenansicht eines vertikalen Mehrwalzen-Kalanders zum Kalandrieren,

Fig. 2a

zeigt schematisch Zwischenwalzen eines Kalanders gemäß Fig. 1 mit einer Biegung für einen Entlastungsdruck zur Einstellung einer steileren Kennlinie gemäß einem ersten Ausführungsbeispiel,

Fig. 2b

zeigt ein Diagramm einer kompensierten und einer durch Walzenbiegungen geänderten Streckenlasten-Kennlinie gemäß Fig. 2a,

Fig. 3a

zeigt schematisch Zwischenwalzen eines Kalanders gemäß Fig. 1 mit einer Biegung für einen Entlastungsdruck zur Einstellung einer vertikalen Kennlinie gemäß einem zweiten Ausführungsbeispiel,

Fig. 3b

zeigt ein Diagramm einer kompensierten und einer durch Walzenbiegungen geänderten Streckenlasten-Kennlinie gemäß Fig. 3a,

Fig. 4a

zeigt schematisch Zwischenwalzen eines Kalanders gemäß Fig. 1 mit einer Biegung für einen Entlastungsdruck zur Einstellung einer Kennlinie mit einer negativen Steigung gemäß einem dritten Ausführungsbeispiel,

Fig. 4b

zeigt ein Diagramm einer kompensierten und einer durch Walzenbiegungen geänderten Streckenlasten-Kennlinie gemäß Fig. 4a,

Fig. 5a

zeigt schematisch Zwischenwalzen eines Kalanders gemäß Fig. 1 mit einer Biegung für einen Belastungsdruck zur Einstellung einer flacheren Kennlinie gemäß einem vierten Ausführungsbeispiel,

Fig. 5b

zeigt ein Diagramm einer kompensierten und einer durch Walzenbiegungen geänderten Streckenlasten-Kennlinie gemäß Fig. 5a,

Fig. 6

zeigt schematisch Zwischenwalzen eines Kalanders gemäß Fig. 1 mit sechs Zwischenwalzen und einer durch Walzenbiegungen variierten Streckenlasten-Kennlinie.

The invention is explained in more detail below on the basis of the exemplary embodiments illustrated in the attached figures.

Fig. 1

shows schematically the side view of a vertical multi-roll calender for calendering,

Fig. 2a

1 schematically shows intermediate rolling of a calender according to FIG. 1 with a bend for a relief pressure for setting a steeper characteristic curve according to a first exemplary embodiment,

Fig. 2b

FIG. 2 shows a diagram of a compensated and a line load characteristic curve according to FIG. 2a changed by roller bending, FIG.

Fig. 3a

1 schematically shows intermediate rolling of a calender according to FIG. 1 with a bend for a relief pressure for setting a vertical characteristic curve according to a second exemplary embodiment,

Fig. 3b

3 shows a diagram of a compensated and a line load characteristic curve according to FIG. 3 a changed by roller bending,

Fig. 4a

1 schematically shows intermediate rolling of a calender according to FIG. 1 with a bend for a relief pressure for setting a characteristic curve with a negative slope according to a third exemplary embodiment,

Fig. 4b

4a shows a diagram of a compensated and a line load characteristic curve changed by roller bending according to FIG. 4a,

Fig. 5a

1 schematically shows intermediate rolling of a calender according to FIG. 1 with a bend for a loading pressure for setting a flatter characteristic according to a fourth exemplary embodiment,

Fig. 5b

5a shows a diagram of a compensated and a line load characteristic curve modified by roller bending according to FIG. 5a,

Fig. 6

shows schematically intermediate rolls of a calender according to FIG. 1 with six intermediate rolls and a line load characteristic curve varied by roll bends.

Fig. 1 shows a vertical multi-roll calender with a frame 1, in which a roll stack of an upper bend-controllable roll 2, a lower bend-controllable roll 3 and three intermediate rolls 4, 5, 6 are arranged supported. The intermediate rolls 4, 5, 6 can be designed as hard or elastic rolls and have different roll diameters. The rolls are arranged one above the other in the roll stack, successive rolls each delimiting a nip, the roll working gap. In the calender shown in FIG. 1, a first nip, called upper nip N _o , lies between the upper bend-controllable roll 2 and the first intermediate roll 4. A nip N ₂ lies between the first intermediate roll 4 and the second intermediate roll 5. A nip N ₃ lies between the second intermediate roller 5 and the third intermediate roller 6. A last nip, called the lower nip N _u , lies between the third intermediate roller 6 and the lower controllable roller 3.

In the nips N _o , N ₂ , N ₃ , N _{u there are} compressive stresses which are determined by the dead weights of the rolls 2, 4, 5, 6 and the associated guide means as well as by loads which can be applied to one end of the roll stack. The force acting in a nip per unit length of the roller is called the line load. In the upper nip N _o, therefore, there is a distributed load q _o, in the nip N ₂ prevails a line load q is _{2, 3} in the nip N there is the line load q ₃ and the lower nip there is the line load q _u. The line load, measured in N / mm, for a number of nip results in a line load characteristic.

The nips N _o , N ₂ , N ₃ , N _u are passed through from top to bottom by a web of material to be processed, in particular a paper web.

The intermediate rolls 4, 5, 6 have roll journals 7, 8, 9 for both sides articulated arrangement. For this purpose, the roller journals 7, 8, 9 are on levers 10, 11, 12 attached to each of which a pressure cylinder 13, 14, 15th acts to deformation forces on the roll neck 7, 8, 9 and thus the Initiate intermediate rolls 4, 5, 6. A bending line B of the intermediate rolls 4, 5, 6 (cf. FIG. 2a) can hereby be set, the Curvature of the bending line B over the amount of the deformation forces introduced can be controlled. The pressure cylinders 13, 14, 15 are preferred Hydraulic cylinder. The pressure cylinders 13, 14, 15 are separate controllable to each intermediate roller 4, 5, 6 individually with a selectable To be able to apply deformation force. The pressure cylinders are preferably 13, 14, 15 double-acting to apply load and relief pressures to initiate on the intermediate rollers 4, 5, 6.

In a method for calendering a web with such a multi-roll calender, a variable characteristic of the compressive stresses in the successive nips N _o , N ₂ , N ₃ , N _u can be achieved by pressing on the roll journals 7, 8, 9 of the intermediate rolls 4, 5 , 6 introducible deformation forces are chosen such that the intermediate rolls 4, 5, 6 receive an essentially identical deflection for exerting loading or relieving pressures, a degree of deflection according to a determinable change in a roller-related line load difference between the upper and lower nip N _o and N _{u is} set and the bend-controllable rollers 2, 3 are adapted to this bend.

For such a determination of the change in the roller-related line load difference only the stiffness and the dead weights the intermediate rollers 4, 5, 6 are taken into account. However, it is not necessary construct these intermediate rollers 4, 5, 6 so that their deflections from their own weight are still the same as each other their bending stiffnesses are equal to each other.

When using different intermediate rolls 4, 5, 6, in particular hard and elastic intermediate rolls, can rather be for each Intermediate roller 4, 5, 6 the height of the setting of a certain degree of bending required deformation forces depending on the respective Flexural rigidity of the respective intermediate roller 4, 5, 6 selected become.

For calendering a material web, a compensated line load characteristic curve K _k (see FIG. 2b) is assumed here, in which overhanging weights are compensated, so that flat line load profiles are present in the nips N _o , N ₂ , N ₃ , N _u . The compensation forces introduced for this purpose are introduced via the pressure cylinders 13, 14, 15. A line load difference Δq _E then follows from the dead weights of the intermediate rolls 4, 5, 6.

To set a desired line load characteristic curve K _B by roller bending (see FIG. 2b), the line loads in the upper nip q _o and in the lower nip q _u are specified independently of one another. A desired lower line load q _{u is} determined on the basis of a compensated line load characteristic curve K _K with an upper line load q _o . If this differs from the inherent weight, the line load characteristic curve K _B becomes steeper or flatter than the compensated line load characteristic curve K _K , since a line load difference Δq _B must be subtracted or added, which results from a total line load from the bending of all intermediate rolls 4, 5, 6 results. The lower line load q _u can be chosen smaller than q _o . The total line load change from the bending is divided into deviations for the mean line loads, here q ₂ and q ₃ , which is achieved by a specific roll bending of the intermediate rolls 4, 5, 6, whereby line load supplements (positive or negative) q _{B are} generated.

For a compensated line load characteristic curve K _K therefore applies q u = q O + Δq e . while K _B applies to the variable line load characteristic .DELTA.Q B = q O + Δq e - q u ,

The division of this line load difference Δq _B by roller bending onto the individual intermediate rollers 4, 5, 6 takes place taking into account the bending stiffness of the intermediate rollers 4, 5, 6, preferably according to the theory of beam bending. Instead of an arithmetically the same. Distribution of the line load difference Δq _B between the number of intermediate rolls 4, 5, 6 is hereby carried out in a manner dependent on the type of roll.

According to a first embodiment shown in FIGS. 2a and 2b the first intermediate roller 4 and the third intermediate roller 6 are identical and designed as a hard, heated roller. The second intermediate roller 5, on the other hand, is designed as an elastic roller.

A predetermined total line load difference Δq _B from roll bending is then divided between the intermediate rolls 4, 5, 6 according to .DELTA.Q B = 2 q hB + 1 q eB . where q _{hB is} the desired line _{load additive} on the hard intermediate rolls 4, 6 from roll bending and q _{eB is} the desired line load additive on the elastic intermediate roll 5 from roll bending. These two line load additives bend the intermediate rollers 4, 5, 6, the deformation forces required for this being applied by the pressure cylinders 13, 14, 15 and introduced into the bearings of the intermediate rollers 4, 5, 6 as additional forces introduced and kept in balance.

To ensure the uniformity of the nip forces, the Bending lines B of the intermediate rolls 4, 5, 6 are adapted to one another. This means, the intermediate rolls 4, 5, 6 are deformed in such a way that those delimited by them Nips are curved substantially the same and consequently to each other run parallel.

The equality of the bending arrows f of the intermediate rolls can be used as a criterion for such an adaptation of the bending lines of the intermediate rolls 4, 5, 6. This leads to the requirement f H = f e . where f _{h is} the bending arrow of the hard intermediate rolls 4, 6 and f _{e is} the bending arrow of the elastic intermediate roll 5. According to the beam theory, the following applies to the deflection of a hard intermediate roller 4, 6 which is articulated on both sides and an elastic intermediate roller 5 under its own weight 5q hB · L 4 384 E. H · J H = 5q eB · L 4 384 E. e · J e

By equating the formulas for the two bending arrows one obtains: q eB e e · J e = q hB e H · J H where E _e , E _h indicate the elasticity modules and J _e , J _h the moments of inertia of the relevant of the respective intermediate rolls. From the above formulas, the desired line _{load additives} q _hB and q _eB can then be determined and corresponding setpoints for the actuation of the cylinders 22 can be calculated. The elasticity modules are known in each case or can be determined experimentally, and the area moment of inertia is predetermined by the geometry of the cross sections of the intermediate rolls 4, 5, 6.

The following applies to the line load supplements sought q hB = .DELTA.Q B 2 + e e · J e e H · J H q eB = .DELTA.Q B 1 + 2 e H · J H e e · J e

The additional journal forces F _h for the hard intermediate rolls 4, 6 belonging to the calculated line load supplements for the roll bends result as follows: F H = q hB paper width 2 the additional journal forces F _e for the elastic intermediate roller 5 result from F e = q eB paper width 2

If a characteristic curve K _{B which} is steeper than the compensated line load characteristic K _{K is} realized, the intermediate rollers 4, 5, 6 bend downwards, ie relief pressures act on the roller journals 7, 8, 9 of the intermediate rollers 4, 5, 6, as is the case with this is illustrated in FIG. 2a by the force arrows F _h and F _e acting from below.

In the first exemplary embodiment shown in _FIGS . 2a and 2b, line _{load supplements} q _hB and q _eB are exemplified by _bending two structurally identical hard intermediate _rollers 4, 6 and an elastic intermediate _roller 5. 2b shows the line _{load additions} q _hB and q _eB in relation to the line _load and FIG. 2a illustrates the degree of curvature of the bending lines B of the intermediate rolls 4, 5, 6. The line load additions q _hB and q _eB are here negative in terms of amount on the compensated line load characteristic K _K, and consequently lead to a steeper variable line load characteristic K _B. In the upper nip N _o there is a line load q _o , which can be adjusted via the upper bend-controllable roller 2. The height of the line load q _o in the upper nip and the height of the line load q _u in the lower nip, due to the dead weights of the rollers 2, 4, 5, 6 and the line load additions of the intermediate roller 4, 5, 6, are shown by force arrows.

The second exemplary embodiment shown in FIGS. 3a and 3b differs from the first exemplary embodiment described above only in that Δq _B corresponds in terms of amount to Δq _E. The result is a vertical variable characteristic curve K _B. Since higher deformation forces than pin forces are introduced here, ie stronger relief pressures are at the intermediate rolls 4, 5, 6, there is a greater degree of curvature for intermediate rolls 4, 5, 6. Otherwise, the explanations for the first embodiment apply accordingly.

The third exemplary embodiment shown in FIGS. 4a and 4b differs from the exemplary embodiments described above only in that Δq _{B is} greater in magnitude than Δq _E. The result is a variable characteristic curve K _B with a negative slope, since q _{u is} smaller than q _o , as is also shown by the force arrows for q _u and q _o . Since even higher deformation forces are introduced than pin forces here, ie there are even stronger relief pressures at the intermediate rolls 4, 5, 6, there is an even greater degree of curvature for intermediate rolls 4, 5, 6. Otherwise, the explanations for the first and second exemplary embodiments apply accordingly.

The fourth exemplary embodiment shown in FIGS. 5a and 5b shows a characteristic curve K _B which is flatter than the compensated characteristic curve K _K due to roll bends, which requires the intermediate rolls 4, 5, 6 to be bent downward. This is also illustrated by the force arrows F _h and F _e , which act on the roll journals 7, 8, 9 of the intermediate rolls 4, 5, 6 from above and consequently initiate loading pressures. Δq _B does not subtract from Δq _{E here} , but adds up, as shown in FIG. 5b. The bending lines B of the intermediate rolls 4, 5, 6 are convex in contrast to a concave shape of the previously described exemplary embodiments. Otherwise, the explanations for these exemplary embodiments apply accordingly.

6 finally shows a concrete numerical example for a flatter characteristic curve K _B by roller bending compared to a compensated characteristic curve K _K. For this purpose, a calender comprises a total of six intermediate rollers 30, 31, 32, 33, 34, 35, in addition to the upper bending-controllable roller 2 and the lower bending-controllable roller 3, of which the intermediate rollers 30, 32 and 35 are cast iron rollers which have a line load q _E of 8.1 N / mm each. The intermediate rolls 31, 33 and 34 are elastic rolls made of aluminum, which cause a line load q _E of 4.6 N / mm each.

For the compensated characteristic curve K _K , an upper line load q _o of zero is assumed, for a lower line load q _u here follows 38.1N / mm. However, if a lower line load q _u of 100 N / mm is desired, the introduction of load pressures on the roll neck of the intermediate rolls is necessary, as a result of which the intermediate rolls receive a convex bending line. the intermediate rolls 30 to 35 are to be additionally loaded by a total of 61.9 N / mm q b = 100 - 38.1 N / mm q B = 61.9 N / mm

If one takes into account the associated elasticity modules and bending moments of inertia of the intermediate rolls 30 to 35 selected here by way of example, it follows q eB = .DELTA.Q B 5,769 = 10.7 N / mm q hB = .DELTA.Q B 6,250 = 9.9 N / mm

Instead of the arithmetic mean 100 N / mm / 6 nips = 16.66 N / mm, additive section _loads from q _eE and q _eB of 4.6 N / mm and 10.7 N / mm, _i.e. 15.3 N / mm, result and from q _hE and q _hB of 8.1 N / mm and 9.9 N / mm, _i.e. 18 N / mm.

The hydraulic pressures of the two bending adjustment rollers 2, 3 are at the described embodiments set so that the Bending lines of the bending adjustment rollers to the predetermined bending lines B the intermediate rollers 4, 5, 6 nestle.

By means of a control unit, the pressures in the pressure cylinders 13, 14, 15 to adjust the intermediate rolls 4, 5, 6 and the pressures in hydraulic Elements of the bending adjustment rollers 2, 3 synchronously with each other be adjusted so that a homogeneity of the line load distributions in all nips even during a print adjustment for a new web preserved. In this way, the elastic ones in particular Payments also in the event of changes during operation of the calender protected from destruction.

In the exemplary embodiments described, the compensated characteristic curve K _K (overhanging weights compensated) was chosen as the reference line, in which plane line load profiles are present. Alternatively, the natural characteristic curve can serve as a reference line without compensation. The calculation of the setpoints must then be adjusted accordingly.

Other deformations have been neglected in the calculation of the setpoints for line load additives q _B described above. For fine adjustment, shear deformations of the intermediate rolls can also be included in the calculation in addition to the bending deformations. In addition, it is possible to also take into account any existing tube revaluations of the intermediate rolls in the calculation.

Alternatively, for a calculation of the line load supplements q _B by roller bending for an adjustment of the bending lines B of the intermediate rollers 4, 5, 6, as another criterion for the uniformity of the nip forces between the intermediate rollers 4, 5, 6, the minimization of the square of the error, formed from the deviations Adjacent bending lines B can be used at a predetermined number of discrete support points.

Claims (11)

1. Method for calendering a product web with a vertical multi-roll calender, in which a plurality of intermediate rolls are arranged between an upper deflection-controlled roll and a lower deflection-controlled roll, this roll pack forms nips with a top and a bottom nip, through which the product web runs, and determines line loads in these nips, whose line-load profile can be changed by introducing deformation forces at roll journals of intermediate rolls, characterized in that the plurality of intermediate rolls have different flexural rigidities and their respective deflection lines B are set to be substantially identical by means of deformation forces which can be introduced individually and on two sides at the roll journals of the intermediate rolls in order to exert loading or relieving forces, a level of the curvature of the deflection line being set in accordance with a determinable change in a roll-induced line-load difference between the top and bottom nips, and the deflection-controlled rolls being matched to this deflection.
2. Method according to Claim 1, characterized in that, for each intermediate roll, the level of the deformation force required to set a specific level of deflection is chosen as a function of the respective flexural rigidity of the respective intermediate roll.
3. Method according to Claim 1 or 2, characterized in that a line load in the top and in the bottom nip is predefined independently of each other, and the deviation between a line-load difference resulting from this and a compensated line-load difference associated with the rolls is divided up into deformation forces for the individual intermediate rolls.
4. Method according to one of Claims 1 to 4, characterized in that the beam deflection of the intermediate rolls is used to calculate desired values for the deformation forces.
5. Method according to Claim 4, characterized in that shear deformations of the intermediate rolls are additionally used to calculate desired values for the deformation forces.
6. Method according to Claim 4 or 5, characterized in that in the case of tubular intermediate rolls, shell deflection is additionally used to calculate desired values for the deformation forces.
7. Method according to Claim 6, characterized in that, in addition, the shell shear deformation of tubular rolls is used.
8. Method according to one of Claims 1 to 7, characterized in that a thickness of the nips is formed uniformly over the length of the rolls.
9. Method according to one of Claims 1 to 8, characterized in that the line-load profiles between two intermediate rolls and between an intermediate roll and a deflection-controlled roll are set with the same shape.
10. Method according to one of Claims 1 to 9, characterized in that a deviation of the line-load difference is set which, in terms of magnitude, corresponds to the compensated line-load difference in order to form a vertical line-load characteristic curve.
11. Vertical multi-roll calender for carrying out the method according to one of Claims 1 to 10, comprising an upper deflection-controlled roll, a lower deflection-controlled roll and a plurality of intermediate rolls arranged between them, which are arranged one above another and form nips between two rolls in each case, through which the product web runs, and at least the intermediate rolls have roll journals on both sides, which are arranged in articulated bearings, to which deformation forces can be introduced via pressure cylinders, characterized in that the plurality of intermediate rolls have different flexural rigidities and the pressure cylinders (13, 14, 15) are designed to be individually controllable and double-acting in order to introduce loading and relieving forces.

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