EP1243694B1 - Calender - Google Patents

Abstract

The calender roll assembly for a pressed paper web has an end preloaded roller stack each with an upper and lower end roller (3,4) and multiple intermediate rollers (6) mounted together in the stack plane. The rollers define working gaps as nips between hard and soft surface rollers. Each roller has a hard intermediate roller and softer end rollers of smaller diameter.

Description

The invention relates to a calender for the treatment of a paper web, in particular from gravure-compatible paper, according to the preamble of the claim 1.

Such a calender is used for the final treatment of a paper web, so that it has a desired value of smoothness, gloss, thickness, bulk and the like. The use of hard and soft rollers enables the formation of soft nips, so-called soft nips, which is essential cause more uniform compression than that by using two each hard rolls formed hard nips. However, they are disadvantageous wear-related shorter downtimes of the soft rollers, which makes the Maintenance effort and the associated downtimes of the known calenders are high. The rapid wear of the soft rollers, in particular roughening them due to the roughness of the Paper web surface, results especially when smoothing higher quality papers, such as in particular those with a high filler content or coated papers, which, in order to be printable, has a high smoothness and smoothing uniformity have to own

EP 0 732 443 B1 discloses the elastic cover of the soft rollers to be replaced with a highly mark-insensitive cover. Such references are expensive, however, taking into account the short life of the soft rollers are particularly important.

The object of the invention is therefore to provide a calender according to the preamble of To create claim 1, which provides very good smoothing results and cheaper in Operation is.

This task is characterized by the characteristics of the characteristic part of the Claim 1 solved.

This creates a calender for the treatment of a paper web thereby reducing the disadvantages of the rapid wear of the soft rollers, that by a mechanical solution, larger diameter of the soft Intermediate rolls versus the diameter of the soft end rolls that Tool life of the soft intermediate rollers can be increased to match the tool life to be adaptable to the soft end rollers. Downtime of the calender for Maintenance measures can thus be reduced because according to the invention essentially all soft rolls of a calender stack have the same service life. The maintenance measures on the soft Rollers are bundled in that they are carried out simultaneously can. According to the invention it was found that they rolled over twice Intermediate rolls, which due to this higher load compared to the simple otherwise, the rolled over end rollers will wear out faster, more slowly wear out when the diameter increases. The use of cheaper roll covers are therefore possible again. Calenders to make glossy papers become cheaper to manufacture and operate. Height Production speeds are realizable.

The design according to the invention is also important because of the Use of soft end rolls in a roll stack is advantageous. The The use of soft end rollers allows the setting of higher ones Temperatures in the first and / or last nip. The finish rolls are common Bending compensation rollers with an inner structure that is high setting Temperatures difficult. If, on the other hand, the second roller is a hard roller, then can be driven with this high temperature.

According to the invention, it was found that only a relatively small Increasing the diameter of the soft intermediate rolls is sufficient to their Adjust the service life to that of the soft end rollers. advantageously, the diameter of a soft intermediate roller is 1.1 to 1.5 times that Diameter of a soft end roller, although the intermediate rollers face each other are rolled over twice on the soft end rollers. The enlargement of the Diameter of the soft intermediate rolls depends on the above Range according to the paper quality, especially the composition of matter, the Coating color composition or the filler content of the treated Paper web. The higher the proportion of roughness-causing Paper web components, the larger the diameter of the soft Intermediate rolls can be selected.

Preferably, all the rolls in a roll stack have their own Power drive to thereby increase the shear stresses in the individual nips minimize. These shear stresses, otherwise caused by the transmission of the Drive power on the rollers through the run of the paper web in the nips arise and increase the wear of the soft intermediate rolls avoided. The diameter of the intermediate rolls can then be increased turn out small.

The diameter is preferably dependent on the web running speed a soft intermediate roller selected such that the rollover frequency is 20 to 25 Hz.

The design according to the invention allows the use of the known Roller loading and / or relieving systems in order in the individual soft nips to be able to adjust certain line loads, so that with individual Line load characteristics can be worked.

The design according to the invention also allows the use of any Roll stack configurations. For two-sided treatment of a paper web two of the roller stacks according to the invention can be connected in series be, the first roll stack for the treatment of a paper web side and the other roll stack to treat the other side of the paper web be used. Following the principle of the calender maker, regardless of the paper quality with as few rollers as possible in order to Maintenance costs and keeping operating costs low are two Series of rolls, each with five rolls, the top and lower end rolls soft rolls are preferred. To optimize the Paper web guides can be separated when using two Roll stacks these are arranged next to each other at different heights, which means that Path length of the paper web between the two roller stacks is shortened and the Introduction of the paper web is simplified. Undesirable changes in Paper web can be avoided.

Alternatively, for a two-sided treatment of the paper web, the at least one a roll stack have six or eight rolls, the upper and lower End roller are soft rollers and an alternating gap between two soft ones Intermediate rolls is formed.

Further embodiments of the invention are the following description and can be found in the subclaims.

Fig. 1

zeigt schematisch die Seitenansicht eines ersten Ausführungsbeispiels eines Kalanders für eine einseitige Behandlung einer Papierbahn,

Fig. 2

zeigt schematisch die Seitenansicht eines zweiten Ausführungsbeispiels eines Kalanders für eine zweiseitige Behandlung einer Papierbahn,

Fig. 3

zeigt schematisch die Seitenansicht eines dritten Ausführungsbeispiels eines Kalanders für eine zweiseitige Behandlung einer Papierbahn,

Fig. 4

zeigt schematisch die Seitenansicht eines vierten Ausführungsbeispiels eines Kalanders für eine zweiseitige Behandlung einer Papierbahn,

Fig. 5

zeigt schematisch die Seitenansicht eines fünften Ausführungsbeispiels eines Kalanders für eine zweiseitige Behandlung einer Papierbahn.

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

Fig. 1

schematically shows the side view of a first embodiment of a calender for a one-sided treatment of a paper web,

Fig. 2

schematically shows the side view of a second embodiment of a calender for a two-sided treatment of a paper web,

Fig. 3

schematically shows the side view of a third embodiment of a calender for a two-sided treatment of a paper web,

Fig. 4

schematically shows the side view of a fourth embodiment of a calender for a two-sided treatment of a paper web,

Fig. 5

shows schematically the side view of a fifth embodiment of a calender for a two-sided treatment of a paper web.

Fig. 1 shows a calender 1 for the treatment of a paper web, in particular made of gravure-proof paper or such a paper that is glossy too is smooth. For this purpose, the calender 1 comprises at least one loadable from the end Roll stack 2 with an upper end roller 3 and a lower end roller 4 and several intermediate rolls 5, 6, 7, together in a roll stacking plane are arranged. The roll stack 2 according to FIG. 1 comprises three intermediate rolls 5, 6, 7 and thus consists of five rolls 2 to 7, which are in a vertical Roll stack level are arranged. Alternatively, the roller stack level inclined or horizontal. Are between two of the rollers 3 to 7 Nips 8, 9, 10, 11 formed which the paper web 12 in a direction D passes.

To form nips in the form of soft nips, in which one hard and one soft To limit a nip roller, rollers 2 through 7 are hard and soft rollers 1, the upper end roller 3 is a soft roller, which upper intermediate roller 5 a hard roller, the middle intermediate roller 6 a soft roller, the lower intermediate roller 7 a hard roller and the lower one End roller 4 is a soft roller. The nips 8 to 11 are therefore all soft nips, in which the paper web 12 passing through the roll stack 2 is smoothed. There only the upper web side of the paper web 12 in the nips 8, 9, 10, 11 in System with the hard rollers 5, 7 reaches and undergoes smoothing there, serves the roll stack 2 for one-sided treatment of a paper web.

The soft rollers 3, 4, 6 are rollers with an elastic cover, the Material can be selected depending on the application. The diameter of the soft The intermediate roller 6 is larger than the diameter of the soft end rollers 3, 4. The diameter of a soft intermediate roller 6 is preferably 1.1 to 1.5 times the diameter of a soft end roller 3, 4. The diameter the two soft end rollers 3, 4 can be identical. In particular Depending on the web running speed, the diameter of a soft intermediate roller 6 can be selected such that the rollover frequency 20 to 25 Hz.

The rollers 3 to 7 are attached to a calender stand 13. The attachment takes place via storage facilities on which lever guides 14, 15, 16, as for the Intermediate rollers 5 to 7 shown, or slide guides 17, as for the end rollers 3, 4 shown, can attack. For opening and closing the roll stack 2, the rollers 3, 4, 5, 6, 7 can be loaded at least from one end. To the Closing the roll stack 2, a hydraulic cylinder 19 is provided here can also be used to load the roll stack 2. The upper End roller 3 is then fixed.

Each roller 3 to 7 is preferably with its own power drive 31 to 35 Mistake.

The upper end roller 3 and the lower end roller 4 are also preferably as Bending adjustment rollers formed. For setting individual line loads, detached from the dead weight of rollers 3 to 7, loading or Relief devices 41, 42, 43 may be provided which act on the lever guides 14, 15, 16 of the intermediate rollers act.

To guide the paper web 12 between the nips 8 to 11, guide rollers 20, 21, 22, 23 are provided. The roll stack 2 can be one on-line or off-line Paper machine can be used.

All hard and possibly soft rollers can be tempered or heated his.

A second can be used to smooth the second side of the paper web 12 according to FIG Roll stack 2 'may be provided, which is connected behind the roll stack 2 and the paper web 12 like the first roll stack 2 from top to bottom passes. The transfer of the paper web 12 from the first roll stack 2 to the second roll stack 2 'forms an alternating gap, since now the side of the Paper web that is smoothed is changed. In the second roll stack 2 ' again smoothed the side of the paper web 12, each in the nips with the hard rollers come into contact. The second roll stack 2 'is preferred constructed exactly like the first roll stack 2, so that for the same components same reference numerals with a prime are used. The The above statements on the roll stack 2 apply accordingly to the roll stack 2 '.

The embodiment of a calender 1 shown in FIG. 3 differs differs from the embodiment of a calender 1 shown in FIG. 2 only in that the second roll stack 2 'is offset in height from the first Roll stack 2 is arranged. The two roll stacks 2, 2 'are preferably like this vertically offset one behind the other that at least only the uppermost nip 8 ' of the second roll stack 2 'is higher than the lowermost nip 11 of the first Roll stack 2. This ensures that while maintaining a sufficient tension of the paper web as straight as possible and thereby also the shortest guidance of the paper web 12 in the alternating gap between the first and second roll stack is reached.

4 shows a calender 100 for the two-sided treatment of a paper web 12, in particular made of gravure-compatible paper or a paper that is to be polished to a high gloss with an alternating gap 150 Roll stack 102. The roll stack 102 is at least from one end resilient and includes an upper end roller 103 and a lower end roller 104 and a plurality of intermediate rolls 105, 106, 107, 108, which together in one Roll stack level are arranged. The roll stack 102 according to FIG. 4 comprises four intermediate rollers 105, 106, 107, 108 and thus consists of six rollers, the are arranged in a vertical roller stack plane. Alternatively, the Roll stack plane inclined or horizontal. Between two of each Rolls 103 to 108 are formed nips 109, 110, 150, 111, 112, which the Paper web 12 passes through in a direction D.

To form nips in the form of soft nips, in which one hard and one soft To limit a nip roller, rollers 103-108 are considered hard and soft 4, the upper end roller 103 is a soft one Roller, the upper intermediate roller 105 a hard roller, two middle one Intermediate rollers 106, 107 each have a soft roller, the lower intermediate roller 108 is a hard roller and the lower end roller 104 is a soft roller. The Nips 109, 110, 111 and 112 are all soft nips between a hard and a soft roller, in each of which the roller stack 2 passing through Paper web 12 on the side that comes into contact with a hard roller, is especially smoothed. The change nip 150 is between the two soft ones Intermediate rollers 106, 107 formed and leads to that in the nips 111 and 112, the other paper web side in contact with the hard roller 108 arrives for a two-sided smoothing of the paper web in a roller stack 102.

The soft rollers 103, 104, 106, 107 are rollers with an elastic one Cover, the material of which can be selected depending on the purpose. The diameter of the the two soft intermediate rolls 106, 107 are each larger than the diameter of the soft end rollers 103, 104. The diameter is preferably one soft intermediate roller 106, 107 1.1 to 1.5 times the diameter of one soft end roller 103, 104. The diameters of the two soft end rollers 103, 104 can be identical. In particular, depending on the Web running speed the diameter of a soft intermediate roller 106, 107 can be selected such that the rollover frequency is 20 to 25 Hz.

The rollers 103 to 108 are attached to a calender stand 113. The Attachment takes place via bearing devices on which lever guides 114, 115, 116, 117 as shown for the intermediate rolls 105 to 108, or sliding guides 118, 119 as shown for the end rollers 103, 104, can attack. To the Opening and closing the roller stack 102, the rollers are at least of resilient at one end. To close the roll stack 102 is one here Hydraulic cylinder 120 is provided, which also loads the roller stack 102 can be used. The upper end roller 103 is then stationary arranged.

Each roller 103 to 108 is preferably with its own power drive 131 provided up to 136.

The upper end roller 103 and the lower end roller 104 are further preferred designed as a bend adjustment roller. For setting individual line loads, detached from the dead weight of rollers 3 to 7, loading or Relief devices 141, 142, 143, 144 can be provided, which on the Lever guides 114, 115, 116, 117 of the intermediate rollers act.

To guide the paper web 12 between the nips 8 to 11, guide rollers 121, 122, 123, 124, 125 are provided. The roll stack 102 can be on-line or off-line a paper machine.

All hard and possibly soft rollers can be tempered or heated his.

The embodiment shown in FIG. 5 differs from that in FIG. 4 illustrated and described embodiment in that the Roll stack 102 comprises eight rolls, i.e. two further intermediate rolls 160, 161, thereby increasing the number of rolls over the changing nip 150. The Intermediate roller 160 is a soft roller, for which the soft roller Intermediate rollers 106, 107 previously said applies accordingly. The intermediate roller 161 is designed as a hard roller. The resulting additional Soft nips 162, 163 increase the smoothing of the in front of the alternating gap 150 treating paper web side. Otherwise, the above statements apply corresponding.

Claims (9)

1. Calender for treating a paper web, especially of paper suitable for gravure printing, having at least one roll stack capable of being loaded from the end and in each case comprising a top and bottom end roll and a plurality of intermediate rolls, which are jointly arranged in a roll stack plane, and the rolls including hard and soft rolls in order to form operating nips in the form of soft nips, charcterized in that each soft roll which forms an intermediate roll (6, 6', 106, 107, 160) has a greater diameter than a soft roll which forms an end roll (3, 4, 3', 4', 103, 104).
2. Calender according to Claim 1, charcterized in that the diameter of a soft intermediate roll (6, 6', 106, 107, 160) is 1.1 to 1.5 times the diameter of a soft end roll (3, 4, 3', 4', 103, 104).
3. Calender according to Claim 1 or 2, charcterized in that all the rolls have their own high-performance drive (31, 32, 33, 34, 35, 31', 32', 33', 34', 35', 131, 132, 133, 134, 135, 136).
4. Calender according to one of Claims 1 to 3, charcterized in that, depending on the web running speed, the diameter of a soft intermediate roll (6, 6', 106, 107, 160) can be chosen in such a way that the loading frequency is 20 to 25 Hz.
5. Calender according to one of Claims 1 to 4, charcterized in that the linear loads in the individual soft nips (8, 9, 10, 11, 8', 9', 10', 11', 109, 110, 111, 112, 162, 163) of a roll stack (2, 2', 102) can be set in accordance with an individual characteristic curve.
6. Calender according to one of Claims 1 to 5, charcterized in that, for the two-sided treatment of the paper web, two of the roll stacks (2, 2') are connected one after the other.
7. Calender according to Claim 6, charcterized in that the two roll stacks (2, 2') connected one after the other each comprise five rolls, and the top (3, 3') and bottom (4, 4') end rolls are soft rolls.
8. Calender according to Claim 6 or 7, charcterized in that the two roll stacks (2, 2') are arranged one after the other with a vertical offset, at least the topmost nip (8') of the second roll stack (2') being higher than the lowest nip (11) of the first roll stack (2).
9. Calender according to one of Claims 1 to 5, charcterized in that, for the two-sided treatment of the paper web, the at least one roll stack (102) comprises six or eight rolls, the top (103) and bottom (104) end rolls being soft rolls and a reversing nip (150) being formed between two soft intermediate rolls (106, 107).

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