EP1505204A1 - Device for treating a web - Google Patents

Abstract

A papermaking dewatering and glazing station (16) has a flexible belt (20) that transports (L) a paper web between a press shoe (26) and an overhead drum (12). The press shoe has rows of individually selectable actuators (24) under a flexible cap (22). The actuators are mechanical, hydraulic, pneumatic, electromagnetic, electromagnetic and/or thermally operated.

Description

The invention relates to a device for treating a material web, in particular for influencing gloss and / or smoothness of a Paper or board web or for dewatering a paper or nonwoven web, with at least one nip between one nipple unit with at least one extended in the running direction broad nip shoe and a guided over the broad nip shoe circumferential flexible band and a complementary counter unit is formed.

Calender arrangements with a shoe roll having a circumferential, having relatively flexible jacket, with the help of a one-piece contact shoe in the direction of a counter roll is resilient, are known. These so-called Breitnipkalander serve the finishing of Papieroder Cardboard sheets. The finishing result, i. Gloss and smoothness, is depending on the nip width measured in the web running direction, by the width of the shoe is determined. Since the shoe in the usual Nip widths is one piece, the nip width can only be changed, by exchanging the shoe for a wider or narrower shoe becomes. Apart from that, according to different nip widths different shoes must be kept ready, which accordingly costly, such a shoe exchange is also extreme consuming.

The invention is based on the object, an improved device of the type mentioned above, in which the in the web running direction measured width of Breitnipschuhs if necessary to the extent possible simple way to change quickly.

This object is achieved in that the Breitnipeinheit Moreover, at least one between the broad nip shoe and arranged around the flexible flexible band, made of flexible and / or elastic material existing plate and several between this and the Breitnipschuh provided, in the web running direction each other comprises the following actuators, over which the results in the web running direction Nipbreite by an appropriate loading of the flexible or elastic plate is variably adjustable. The counter unit can doing a counter-roll, one in the required manner guided and supported counter-belt or the like exist.

Due to this design, the compressive stress in the nip in particular with constant force application fast and almost be changed infinitely or very sensitively. The "window" for the Satinage conditions will be increased accordingly. Independent of each set nip width always results in a coherent, optimal tread for the hydrodynamic lubricating film.

From DE 43 22 876 A1 is a smoothing device with a sectioned Wide nipple known. The sectioning of the shoe is used here but only to compensate for production-related tensions to provide over the smoothing zone. A variation of the shoe width is not intended.

In a device known from DE 195 44 979 A1 for compressing, Smoothing and / or dewatering of a fibrous web is at least a support element used in several, in the direction of passage the fibrous web successive support element sections is divided. However, the subdivision of the support element only serves here to, in the web running direction, a pressure profile with at least two consecutively To produce lying maximum pressure.

Advantageously, the actuators of the device according to the invention separately and / or in groups controllable.

The area between the flexible or elastic plate and the circumferential flexible band is in particular hydrodynamic and / or hydrostatically lubricated, so that the circulating flexible band optimal can slide over the plate.

In particular, mechanical, hydraulic, pneumatic, electromechanical, electromagnetic and / or thermal actuators be provided.

In an expedient practical embodiment of erfindungemäßen Device, the actuators are at least partially by a respective cylinder / piston unit formed. These actuators can For example, at least partially by a respective hydraulic cylinder / piston unit be formed. These actuators are preferred at least partially by a respective double-acting cylinder / piston unit educated.

In a further advantageous embodiment of the device according to the invention, the flexible or elastic plate is provided on its side facing the broad nip with successive in the web running direction, each extending in the transverse direction sealing strips which enter provided in Breitnipschuh slots to between the Breitnipschuh and the bendable or elastic plate formed by the sealing strips limited pressure chambers which are acted upon for variable adjustment of the resulting nip width in the web running direction accordingly with pressurized fluid. The pressure chambers are expediently acted upon by pressurized fluid via feed channels provided in the wide nip shoe.
As an alternative to the pressure chambers delimited by the sealing strips, correspondingly controllable hoses can advantageously be provided in the chambers formed by the slots and in these engaging strips, whereby any sealing between moving parts is eliminated. If the flexible or elastic plate is formed in this case without webs and supported directly over the hoses, resulting in a more mobile and easy tilting arrangement.

In a further advantageous embodiment of the invention Device is between the broad nip shoe and the flexible or elastic plate arranged an elastomer profile, the more in the web running direction having successive pressure chambers, the variable Setting the resulting nip width in the web running direction accordingly be acted upon with pressurized fluid.

Particularly advantageous is also such an embodiment in which between the broad nip shoe and the flexible or elastic plate arranged in the web running direction consecutive Einstellnocken several are, in which case the resulting in the web running direction Nipbreite is variably adjustable via this adjustment cam.

In a further advantageous embodiment of the invention Device are between the broad nip shoe and the flexible or elastic plate several consecutive in the web running direction arranged thermal actuators, which are in the web running direction resulting nip width in the present case about these thermal actuators is variably adjustable. Preferably, the thermal actuators exist each of thermally conductive material, wherein each of a Heat medium are flowed through and resulting in the web running direction Nipbreite by a corresponding variation of the temperature of the Heat medium is variably adjustable.

The broad nip shoe can in particular over several in the transverse direction successive, supported on an axis Anpress units acted upon be. The Anpresseinheiten are preferably separated and / or group-driven. This is in particular a compensation the axis bending occurring under load is possible.

The Breitnipeinheit can in particular by a Breitnipwalze with a via the flexible or elastic plate guided flexible roll shell be formed.

According to a preferred practical embodiment, the Device according to the invention at least one Breitnipkalander.

Figur 1

eine schematische Darstellung eines zwischen einer Breitnipeinheit und einer Gegenwalze gebildeten Breitnips einer Vorrichtung zur Beeinflussung von Glanz und/oder Glätte einer Materialbahn, wobei die zwischen dem Breitnipschuh und der biegsamen bzw. elastischen Platte vorgesehenen Aktuatoren durch doppelt wirkende Zylinder/Kolben-Einheiten gebildet sind,

Figur 2

eine schematische Darstellung einer Ausführungsform, bei der die biegsame bzw. elastische Platte über zwischen dieser und dem Breitnipschuh gebildete, durch Dichtleisten begrenzte Druckkammern beaufschlagbar ist,

Figur 3

eine schematische Darstellung einer Ausführungsform, bei der zwischen dem Breitnipschuh und der biegsamen bzw. elastischen Platte ein mehrere Druckkammern aufweisendes Elastomerprofil angeordnet ist, wobei im vorliegenden Fall alle Druckkammern unter Druck stehen,

Figur 4

eine mit der Figur 3 vergleichbare Darstellung, wobei jedoch sowohl am einlaufseitigen als auch auslaufseitigen Ende des Elastomerprofils jeweils zwei Druckkammern drucklos sind, d.h. nur die verbleibenden mittleren Druckkammern unter Druck stehen,

Figur 5

eine schematische Darstellung einer Ausführungsform, bei der zwischen dem Breitnipschuh und der biegsamen bzw. elastischen Platte mehrere Einstellnocken angeordnet sind, wobei im vorliegenden Fall die biegsame bzw. elastische Platte zur Einstellung einer maximalen Nipbreite durch alle Einstellnokken entsprechend beaufschlagt ist,

Figur 6

eine mit der Figur 5 vergleichbare Darstellung, wobei jedoch sowohl am einlaufseitigen als auch am auslaufseitigen Ende des Breitnipschuhs jeweils zwei Einstellnocken zur Einstellung einer verringerten Nipbreite entsprechend verdreht sind,

Figur 7

eine schematische Darstellung einer Ausführungsform, bei der zwischen dem Breitnipschuh und der biegsamen bzw. elastischen Platte mehrere thermische Aktuatoren angeordnet sind, und

Figur 8

eine schematische Darstellung einer Variante der Ausführungsform nach Figur 2, bei der anstelle von Druckkammern flexible Betätigungsschläuche vorgesehen sind.

The invention will be explained in more detail below with reference to an embodiment with reference to the drawing; in this show:

FIG. 1

a schematic representation of a formed between a Breitnipeinheit and a backing roll wide nip of a device for influencing gloss and / or smoothness of a web, said provided between the wide nip shoe and the flexible or elastic plate actuators are formed by double-acting cylinder / piston units,

FIG. 2

a schematic representation of an embodiment in which the flexible or elastic plate can be acted upon by this formed and the wide nip shoe, limited by sealing strips pressure chambers,

FIG. 3

a schematic representation of an embodiment in which between the broad nip shoe and the flexible or elastic plate a plurality of pressure chambers exhibiting elastomer profile is arranged, in the present case, all the pressure chambers are under pressure,

FIG. 4

a representation comparable to that of FIG. 3, but in each case two pressure chambers are depressurized both on the inlet side and outlet side end of the elastomer profile, ie only the remaining medium pressure chambers are under pressure,

FIG. 5

a schematic representation of an embodiment in which a plurality of adjusting cams are arranged between the broad nip shoe and the flexible or elastic plate, wherein in the present case, the flexible or elastic plate for setting a maximum nip width is acted upon by all Einstellnokken accordingly,

FIG. 6

a representation comparable to that of FIG. 5, wherein, however, in each case two adjusting cams for adjusting a reduced nip width are correspondingly twisted both on the inlet side and on the outlet side end of the broad nip shoe,

FIG. 7

a schematic representation of an embodiment in which a plurality of thermal actuators are arranged between the broad nip shoe and the flexible or elastic plate, and

FIG. 8

a schematic representation of a variant of the embodiment of Figure 2, in which instead of pressure chambers flexible actuating hoses are provided.

Figure 1 shows a schematic representation of a between a Breitnipeinheit 10 and a counter-roller 12 formed Breitnip 14 of a device 16 for influencing the gloss and / or smoothness of a material web, in particular, it is a paper or board web can act.

The wide nip unit 10 comprises at least one in the web running direction L. extended broad nip shoe 18 and a guided over the wide-nip shoe 18 circulating flexible band 20. This can be wide nip unit 10 in particular by a Breitnipwalze with a on the broad nip shoe 18 or a associated with this, further under even closer to descriptive flexible or elastic plate guided flexible roll shell 20 be formed.

The device 16 in question may in particular be a Breitnipkalander act.

As can be seen from Figures 1 to 8, the Breitnipeinheit 10 moreover comprises at least one arranged between the Breitnipschuh 18 and the rotating flexible band 20 plate 22 made of flexible and / or elastic material and a plurality between this flexible or elastic plate 22 and the Breitnipschuh 18 provided, in the web running direction L successive actuators 24 _i , over which the resulting in web direction L nip width B _i is variably adjustable by a corresponding application of the flexible or ealstischen plate 22.

The actuators 24 _i are preferably separately and / or group-controlled. The area between the flexible or elastic plate 22 and the circulating flexible band 20 is in particular hydrodynamically and / or hydrostatically lubricated. In particular, mechanical, hydraulic, pneumatic, electromechanical, electromagnetic and / or thermal actuators 24 _i may be provided.

The wide-nip shoe 18 can cross each other over several in the transverse direction following, on an axis supported Anpresseinheiten 26 acted upon be. These pressing units 26 are expediently separated and / or group-wise controllable, so that a respective under load occurring axis bending can be compensated.

Figure 1 shows a schematic representation of an exemplary embodiment in which between the wide nip shoe 18 and the flexible or elastic plate 22 as actuators double-acting hydraulic cylinder / piston units 24 _{1 are} provided.

The broad nip shoe 18 is thus equipped on its side facing the counter roller 12 with actuators 24 ₁ , which act on a flexible or elastic plate 22 whose top is hydrodynamically or hydrostatically lubricated, so that the circumferential flexible band 20 optimally slide over the plate 22 can. By a corresponding activation of the actuators 24 ₁ , the nip width resulting in the web running direction L can be changed in the desired manner.

In the embodiment according to FIG. 2, the flexible or elastic plate 22 is provided on its side facing the broad nip shoe 18 with a plurality of sealing strips 28 which follow one another in the direction of web travel L and extend in each case in the transverse direction. The sealing strips 28 are guided in slots 30 provided in the wide-nip shoe 18. Accordingly, laterally limited pressure chambers 24 _{2 are} formed between the wide-nip shoe 18 and the flexible or elastic plate 22 by the sealing strips 28, which can be acted upon correspondingly with pressure fluid for the variable adjustment of the nip width resulting in the web running direction L. In the present case, the actuators in question thus include the pressure chambers 24 ₂ provided between the broad nip shoe 18 and the flexible or elastic plate 22 and bounded by the sealing strips 28.

As can be seen with reference to FIG. 2, the pressure chambers 24 ₂ in the present case can be acted upon by pressurized fluid, in particular pressure oil, via feed channels 34 provided in the wide-nip shoe 18 and fed via a respective feed 32.

In the embodiment shown in Figures 3 and 4, an elastomeric profile 36 is disposed between the wide nip shoe 18 and the flexible or elastic plate 22, which has a plurality of consecutive in the web running direction pressure chambers 24 ₂ , for the variable adjustment of the resulting in web direction L nip width B _i accordingly with pressurized fluid, such as pressurized oil, can be acted upon. In the present case, the relevant actuators thus include the pressure chambers 24 ₂ provided in the elastomer profile 36.

In the illustration according to FIG. 3, all the pressure chambers 34 _{3 are} under pressure, so that a maximum nip width B ₁ results, which means a correspondingly wide support of the circulating flexible band 20 on the counter-roller 12.

In contrast, two pressure chambers 24 ₃ 'are depressurized both in the representation on the inlet side and on the outlet side end of the elastomer profile 36, ie, only the remaining medium pressure chambers 24 ₃ "are under pressure, thus resulting in a correspondingly lower pressure Nip width B ₂ , which corresponds to a correspondingly narrower circulation of the circulating flexible band 20 on the counter-roller 12. Since the pressure chambers are individually controllable, it is also possible to relieve the middle part and to create alternating pressure-loaded and pressure-relieved zones in the running direction.

In the embodiment shown in FIGS. 5 and 6, a plurality of adjustment cams 24 ₄ following one another in the web running direction L are arranged between the wide-nip shoe 18 and the flexible or elastic plate. The variable adjustment of the nip width B _i resulting in the web running direction L is variably adjustable are.

In the illustration according to FIG. 5, the flexible or elastic plate 22 for setting a maximum nip width B ₁ or a wide support of the circulating flexible band 20 on the mating roll 12 is acted upon accordingly by all setting cams 24 ₄ .

In contrast, in the illustration according to FIG. 6, two adjustment cams 24 ₄ 'are respectively correspondingly rotated both on the inlet side and on the outlet side end of the broad nip shoe 18 in order to set a reduced nip width B ₂ . The flexible or elastic plate 20 is therefore pressed against the counter-roller 12 only by the remaining central adjusting cams 24 ₄ ", as already mentioned in connection with the embodiment according to FIG. 4 and also valid for the further embodiments, in the web running direction For example, alternating pressure-loaded and pressure-relieved zones are created, and it is also possible to relieve, for example, the middle part or desired subregions.

With the smaller nip width B ₂ , a correspondingly narrower support of the circulating flexible band 20 on the counter-roller 12 results again.

In the embodiment according to FIG. 7, a plurality of thermal actuators 24 ₅ following one another in the web running direction L are arranged between the wide-nip shoe 18 and the flexible or elastic plate 22. In this case, the nip width resulting in the web running direction L can be set variably via these thermal actuators 24 ₅ .

The thermal actuators 24 ₅ each consist of thermally conductive material, wherein they are traversed by a heat medium. In the present case, the nip width resulting in the web running direction L is thus variably adjustable by a corresponding variation of the temperature of the heat medium.

The embodiment of Figure 8 corresponds in its basic structure of the embodiment of Figure 2, but instead of the pressure chambers provided there receiving chambers for individually controllable flexible tubes 37 are provided. The use of such pressurizable hoses leads to the advantage that no seals are required between moving parts.
If in this case the flexible or elastic plate is formed without webs and the guided in corresponding recesses of Breitnipschuhs 18 or content Erten pressure hoses 37 directly to the plate 22, so there is a more mobile compared to the embodiment shown in Figure 8 and easier tilting arrangement.

With the embodiment of the broad nip shoe according to the invention can be the compressive stress in the nip in a simple way quickly and very sensitively to change.

Although the invention is particularly advantageous for influencing gloss and / or smoothness of a paper or board web can be used, its scope is not limited to this. advantageously, The invention can also be used in press sections for dewatering Railways serve, are used in this case by targeted Actuation of the actuators corresponding application-specific advantages achieve.

LIST OF REFERENCE NUMBERS

10

Breitnipeinheit

12

backing roll

14

nip

16

contraption

18

Breitnipschuh

20

flexible band, flexible roll jacket

22

flexible or elastic plate

24 _i

actuator

24 ₁

Cylinder / piston unit

24 ₂

pressure chamber

24 ₃

pressure chamber

24 ₄

adjustment cams

24 ₅

thermal actuator

26

pressing unit

28

sealing strip

30

slot

32

Intake

34

feed

36

elastomer profile

37

tube

B _i

nip width

L

Web direction

Claims (19)

Device (16) for treating a material web, in particular for influencing the gloss and / or smoothness of a paper or board web or for dewatering a paper or nonwoven web, having at least one broad nip (14) between at least one nip unit (10) formed in the web running direction (L) extended nip shoe (18) and a guided over the wide nip shoe (18) circulating flexible band (20) and a complementary counter unit (12),
characterized in that the extended nip unit (10) moreover comprises at least one plate (22) made of flexible and / or elastic material between the broad nip shoe (18) and the circulating flexible band (20) and a plurality between this and the broad nip shoe (18). provided, in the web running direction (L) successive actuators (24 _i ), via which in the web running direction (L) resulting nip width (B _i ) by a corresponding application of the flexible or elastic plate (22) is variably adjustable. Device according to claim 1,
characterized in that the actuators (24 _i ) are separated and / or controlled in groups. Apparatus according to claim 1 or 2,
characterized in that the region between the flexible or elastic plate (22) and the circulating flexible band (20) is hydrodynamically and / or hydrostatically lubricated. Device according to one of the preceding claims,
characterized in that mechanical, hydraulic, pneumatic, electromechanical, electromagnetic and / or thermal actuators (24 _i ) are provided. Device according to one of the preceding claims,
characterized in that the actuators (24 _i ) are at least partially formed by a respective cylinder / piston unit (24 ₁ ). Device according to claim 5,
characterized in that the actuators (24 _i ) are at least partially formed by a respective hydraulic cylinder / piston unit (24 ₁ ). Apparatus according to claim 5 or 6,
characterized in that the actuators (24 _i ) are at least partially formed by a respective double-acting cylinder / piston unit (24 ₁ ). Device according to one of claims 1 to 4,
characterized in that the flexible or elastic plate (22) on its broad nip shoe (18) facing side with a plurality in the web running direction (L) successive, each extending in the transverse direction sealing strips (28) is provided in the Breitnipschuh (18 ) provided slits (30) to form between the broad nip shoe (18) and the flexible or elastic plate by the sealing strips limited pressure chambers (24 ₂ ), which for variable adjustment of the web running direction (L) resulting nip width (B _i ) can be acted upon accordingly with pressurized fluid. Device according to claim 8,
characterized in that the pressure chambers (24 _i ) in the broad nip shoe (18) provided feed channels (34) can be acted upon with pressurized fluid. Device according to one of claims 1 to 4,
characterized in that the flexible or elastic plate (22) on its broad nip shoe (18) facing side with a plurality in the web running direction (L) successive, each in the transverse direction extending strips (28) is provided in the Breitnipschuh (18 ) provided slits in which for the variable adjustment of in the web running direction (L) resulting nip width (B _i ) and / or for specifying a freely selectable load profile in the web running direction (L) in each case an individually controllable pressure hose (37) is provided. Device according to claim 10,
characterized in that the pressure hoses (37) are arranged in guiding and retaining recesses of the broad nip shoe (18) and the flexible or elastic plate (22) is supported directly on the hoses (37). Device according to one of claims 1 to 4,
characterized in that between the wide nip shoe (18) and the flexible or elastic plate (22) an elastomeric profile (36) is arranged, which has a plurality in the web running direction (L) successive pressure chambers (24 ₃ ), for the variable adjustment of in the web running direction (L) resulting Nipbreite (B _i ) are acted upon accordingly with pressurized fluid. Device according to one of claims 1 to 4,
characterized in that between the broad nip shoe (18) and the flexible or elastic plate (22) several successive adjusting webs (24 ₄ ) are arranged in the web running direction (L) and that the nip width (B _i ) resulting in the web running direction (L) About this adjustment cam (24 ₄ ) is variably adjustable. Device according to one of claims 1 to 4,
characterized in that between the broad nip shoe (18) and the flexible or elastic plate (22) in the web running direction (L) successive thermal actuators (24 ₅ ) are arranged and that in the web running direction (L) resulting nip width (B _i ) Is variably adjustable via these thermal actuators (24 ₅ ). Device according to claims 14,
characterized in that the thermal actuators (24 ₅ ) each consist of thermally conductive material and are flowed through by a heat medium and that in the web running direction (L) resulting nip width (B _i ) is variably adjustable by a corresponding variation of the temperature of the heat medium. Device according to one of the preceding claims,
characterized in that the broad nip shoe (18) is acted upon by a plurality of laterally following, on an axis supported Anpresseinheiten (26). Device according to claim 16,
characterized in that the Anpresseinheiten (26) are separated and / or controlled in groups. Device according to one of the preceding claims,
characterized in that the Breitnipeinheit (10) by a Breitnipwalze with an over the flexible or elastic plate (22) guided flexible roll shell (20) is formed. Device according to one of the preceding claims,
characterized in that it comprises at least one Breitnipkalander.

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