Sleeve change calendar for rotary embossing of multi-ply tissue webs

Abstract

The present invention relates to a sleeve-changing calender (1) for rotary embossing a multi-ply tissue web or for producing ply bonds between the individual plies of a multi-ply tissue web, the sleeve-changing calender (1) having a roll frame (7) on which at least one roll (12, 13) is mounted, the roll frame (7) being fitted with an expandable support core (3) and an exchangeable sleeve (4), the sleeve being pressable into the support core for assembly and being fixed to the support core by a friction fit, the support core being designed with a multi-chamber system (11) for individually applying pressure to separate pressure zones (10).

Description

[Technical field]

[0001] The present invention relates to a sleeve-changing calender for rotary embossing a multi-ply tissue web or for producing ply bonds between the individual plies of a multi-ply tissue web, the sleeve-changing calender having a roll frame on which at least one roll is mounted, on which an expandable support core and an exchangeable sleeve are mounted, the sleeve being capable of being pressed into the support core for assembly and being fixed to the support core by a friction fit. A sleeve-changing calender is known, for example, from EP 1 967 360 A2.

[0002] However, the prior art is not aware of a sleeve-changing calender that is able to generate different pressures over the extension of the embossing nip, but this has the technical advantage that the pressure gradient in the embossing nip can be precisely adapted to the product and the pattern to be embossed.

[0003] Therefore, an object of the present invention is to provide a sleeve changing calendar which is more flexibly adjustable and produces better embossing results.

[0004] This object is achieved by a device or a method with the features of the independent claims.

[0005] It is therefore provided that the support core is designed with a multi-chamber system for individually applying pressure to separate pressure zones.

[0006] The local selectivity in setting different pressures in the various pressure zones has the advantage that a higher pressure can be applied in particular in the areas where the embossing pattern is to be created, whereas the non-embossed areas of the tissue to be embossed can be passed through the embossing nip with a lower pressure. This advantage is particularly important when embossing paper handkerchiefs, where embossed and non-embossed areas are created. Typically, several tissue webs are embossed adjacent to each other in the axial direction of the roll. It can be provided that each chamber of the multi-chamber system has at least one pressure zone. The several pressure chambers may be arranged axially spaced from each other. It can be provided that the sleeve change calendar can also be designed for the embossing of woven or nonwoven materials.

[0007] Within the meaning of the present invention, a tissue web may be a non-woven fabric or a nonwoven fabric. In particular, the tissue web may comprise a tissue material that includes or consists of paper. For example, the tissue web may be tissue paper, such as paper towels, such as sanitary paper made of cellulose. The tissue web may be used for the manufacture of toilet paper, kitchen paper, paper napkins, or paper handkerchiefs.

[0008] It may be provided that each pressure zone has at least one fluid channel. It may be provided that the support core is provided with a plurality of, for example at least four, different pressure zones. In particular, it may be provided that applying an individual pressure to each pressure zone or applying different pressures to all pressure zones allows the generation of different selective and / or spatially resolved embossing zones. The pressure zones may be divided along the axial direction of the roll. The width of the pressure zones may differ. The pressure zones may all have the same width. This allows the outer diameter of the sleeve to be modified by pressure, which modification can be set individually in the different pressure zones by providing different fluid pressures.

[0009] Preferably, the sleeve exchange calendar has a three-part structure with a central support core onto which a first zone sleeve with pressure zones is pressed or shrunk. An exchangeable sleeve with engravings on its periphery is pressed onto its periphery. The pressure zones can be formed as recesses on the inside of the zone sleeve facing the support core. At least one fluid channel can lead to each of the recesses, via which individual fluid pressures can be applied to the pressure zones.

[0010] Preferably, the pressure zones are arranged according to the embossing pattern of the sleeve to affect the embossed image of the sleeve. Alternatively or additionally, the different pressure zones can be subjected to pressure so as to provide a uniform embossing pressure over the entire length of the calender or the entire width of the tissue web. In particular, the various pressure zones along the length of the calender can be subjected to a load such that the calender bulges in the unloaded state, resulting in a larger diameter towards the center compared to the areas close to the end bearings of the calender. In applications where the calender is forced into the opposing roll through opposing bearing points, the pressure of the pressure zones can be adjusted to provide an essentially constant embossing pressure over the entire length of the roll and thus over the entire width of the embossing.

[0011] It can therefore be provided that the outer diameter of the sleeve can be partially pressure-controlled via hydraulic pressure which is separately adjustable in the individual pressure zones of the support core.

[0012] It can be provided that the support core, in particular the first support core element, is provided with at least one rotary feedthrough for transmitting hydraulic oil.

[0013] The pressure zones, or the hydraulic cylinders assigned to the pressure zones, can each receive pressure via a separate media channel connected to at least one rotary feedthrough.

[0014] Thus, the support core or expander can be designed with a multi-chamber system to accommodate different pressure loads and a rotary feedthrough for transmitting hydraulic oil in separate media channels.

[0015] It may be specified that the media channel is designed for a maximum operating pressure of 80 to 400 bar.

[0016] The support core may be configured in such a way that the attached sleeve can remain securely in place even in the event of an emergency stop and / or loss of voltage and / or hydraulic shutdown / failure. For this purpose, a set hydraulic pressure can be clamped into the support core. It may be provided, for example, that the hydraulic pressure is maintained via a built-in lockable check valve.

[0017] The support core may be provided with an outer surface that is conically ground and / or coated with a highly wear-resistant material. The highly wear-resistant material may, for example, comprise or be chromium or tungsten carbide. The conically ground surface therefore facilitates the quick removal and installation of the sleeve, allowing for a quick replacement of the sleeve. The chrome plating of the outer surface, for example by combining steel and chrome, also ensures a low coefficient of friction between the inner circumference of the sleeve and the outer circumference of the support core, although other material combinations with the same effect may be considered.

[0018] The sleeve may be made from high strength tool steel and / or have a textured surface.

[0019] The support core may be specified to be supported at three points on the roll frame. This increases the stiffness of the shaft. The third bearing may be designed as a hydrodynamic plain bearing.

[0020] It can be provided that the support core bearings can be temperature controlled via a bearing cooling system, in particular by cooling all the support core bearing points. The bearing cooling can be configured, for example, in the bearing cover. This means that the bearing cooling can be designed to be much greater than previously known solutions. This ensures a smoother operation and, as a result, less vibration.

[0021] It may be provided that the drive side bearing is permanently mounted within the roll frame or slide.

[0022] It can also be provided that the bearing on the operating side opposite the bearing on the drive side is designed as a folding bearing and / or that the roll bearing on the operating side can be opened and closed via a linear guide. The provision of a folding bearing or linear guide allows the bearing to be folded easily and quickly, in particular when changing the sleeve, and thus allows quick access to the sleeve to be changed.

[0023] The driving side bearings can be firmly installed in the machine frame or slide, and the operating side bearings can be designed as folding bearings so that they can be pulled out and swung sideways when changing the sleeve.

[0024] The sleeve-changing calender can also be equipped with a changing device for the easy exchange of the support cores or rolls directly in the machine. The rolls or support cores of the sleeve-changing calender can be exchanged with minimal effort thanks to the automatic tensioning system. When changing the sleeve or roll or the support core, the bearing on the operating side can be easily opened and closed, again by using linear guides or folding bearings.

[0025] In particular, it can be specified that the sleeve changing calendar has an upper roll and a lower roll, and the center offset of the upper roll relative to the lower roll is adjustable, the advantage of which is that the center offset of the upper roll relative to the lower roll can be adjusted, thus ensuring uniform bearing zero point determination during the embossing process.

[0026] The sleeve changing calendar is also provided with an active nip control, by means of which an adjustable pressure in the roll nip can be selectively controlled for different pressure zones. It can further be provided that the pressure in the roll nip is hydraulically adjustable. It can be provided that the nip between the upper and lower roll is adjustable by means of a threaded spindle with a fine thread, which preferably adjusts adjustable wedges forming the nip. The nip adjustment between the lower sleeve embossing roll and the upper sleeve embossing roll can be performed using adjustable wedges, so that these are manually adjustable or automatically adjustable by means of a threaded spindle with a fine thread. A scale can be provided with which the nip setting data can be reproduced. Alternatively it can be provided that the nip setting data is mechanically adjustable in another way. Furthermore the wedges can be hydraulically adjustable. Furthermore the nip adjustment can be performed in a piezoelectric way. Alternatively fixed spacers can be provided for this purpose.

[0027] Alternatively or additionally, it can be provided that the nip between the upper and lower rolls can be adjusted by at least two single-acting or double-acting hydraulic cylinders for opening and closing the roll nip. Alternatively, the roll nip can be adjusted via a spindle.

[0028] A combination of mechanical / hydraulic roll adjustment can be implemented in such a way that, for example, the pre-adjustment is performed hydraulically via an adjustable wedge and then the fine adjustment is performed manually with a fine-threaded threaded spindle. Furthermore, it is possible to control and adjust the hydraulic pressure of the roll adjustment separately for the drive side and the operating side.

[0029] It can be provided that the sleeve change calendar is provided with at least one laser reference unit for detecting, in particular, the axial and / or radial position of the sleeve on the support core, the detection of the position of the sleeve on the support core being performed by at least one detectable reference point arranged on the sleeve surface. This allows the sleeve to be set up automatically. The laser reference ensures that the embossed engravings of the upper and lower sleeves are precisely aligned. The laser automatically detects the reference points or registration marks on the sleeve surface to allow the axial and radial adjustments to be performed automatically. For this purpose, the lower or upper support core can be moved axially by a motor, the radial adjustments being performed by a drive motor. The support core together with the embossed sleeve mounted thereon can then be driven at a precise angle using a servo drive motor. Then, if necessary, final fine adjustments can be made during production via the user interface.

[0030] It can be provided that the embossed engravings of the upper and lower rolls can be aligned with each other via at least one laser reference unit, reference points on the sleeve surface can be detected via a laser, and the corresponding axial and / or radial adjustment of the rolls with respect to each other is performed via a motor-driven axial adjustment and / or a drive motor-driven radial adjustment of at least one of the lower support cores. In a pair of rolls, each roll can have a pair of markings, each pair of markings consisting of a first marking running parallel to the roll axis and a second marking running at an angle between 0° and 90°, preferably 45°, to the first marking. The markings can be arranged axially on the edges of the outer surfaces of the upper and lower rolls. This allows easy scanning of the markings using at least one scanning unit that can be arranged at a distance from the roll surface and therefore from the markings.

[0031] It may be provided that the roll frame may be designed with a closed design and may be equipped with a side stand with welded cross members and integrated vibration damping components.

[0032] For example, a sleeve changing calender can be designed for rotary embossing of multi-ply tissue webs. All types of processes can be performed: dot / dot, or alternating, or dot / smooth embossing. Embossing creates ply bonds between the individual plies of the multi-ply tissue web. A solid roll, e.g., a rubber surface, can also be used for embossing.

[0033] Sleeve embossing rolls can be designed as permanently installed, expandable supports onto which replaceable sleeves can be pressed and secured by pressure and / or friction. These sleeves may be made of high strength tool steel and have an engraved surface.

[0034] It can be provided that the adjustment of the support core is carried out via at least one single-acting or double-acting hydraulic cylinder. Alternatively or additionally, mechanical means for adjusting the support core can also be provided.

[0035] It may be provided that the support core bearing is provided with a hydraulic clearance release for the first support core element and / or the second support core element, for example a triple bearing set, particularly including precision rolling bearings, may be provided with a hydraulic clearance release for the upper support core and the lower support core.

[0036] It can further be provided that the second support core element, which is vertically or horizontally displaceable, is mounted in a preloaded and / or ball-bearing precision linear guide in the slide. For example, the vertically displaceable lower extended support core can be provided with a set of bearing guides, and the linear guide can be designed as a preloaded ball-bearing precision linear guide.

[0037] The invention further relates to an apparatus comprising a sleeve exchange calendar according to any one of the preceding claims and a sleeve exchange carriage designed to push the sleeve into or push the sleeve out of the support core. The sleeve exchange carriage can comprise an AGV, so that the sleeve exchange carriage can be moved automatically towards or away from the sleeve exchange calendar. The sleeve exchange carriage can be provided with a height-adjustable support surface. The support surface can be provided with a roll conveyor, in particular a rubber roll conveyor, for moving the sleeve on the sleeve exchange carriage. The support surface can be at least partially groove-shaped for laterally fixing the filled sleeve. The support surface can be designed such that the sleeve exchange carriage can receive two sleeves, in which apparatus the sleeves are preferably arranged one above the other on the carriage in parallel. This allows a faster sleeve exchange by loading a "new" sleeve, which is mounted in one of the sleeve support positions of the carriage, and moving to the sleeve exchange calendar with the empty sleeve support position. After loading the sleeve to be removed, the sleeve exchange carriage changes position so that the sleeve to be installed can be moved, for example, laterally or pushed onto the support core by a carousel provided on the sleeve exchange carriage. The carousel has two support positions that can be alternately aligned with the calendar. This avoids additional movements of the sleeve exchange carriage.

[0038] The present invention also relates to a method for changing a sleeve on a sleeve changing calendar as described above, comprising the steps: - positioning the front face of the movable sleeve changing carriage against the calendar; -loosening the support core; - pushing the sleeve to be removed from the support core into a sleeve exchange carriage; - pushing the sleeve to be mounted from the sleeve exchange carriage onto the support core; Includes.

[0039] The method may also allow the sleeve to be manually pressed on and off.

[0040] The method may further comprise providing the sleeve changing carriage with a take-off device, such as a cable winch or a driven roll conveyor, to enable automatic pushing from or pushing into the support core.

[0041] The method may further include sliding the sleeve to be mounted from the sleeve exchange carriage onto the support core, followed by aligning the support core with a laser reference unit and clamping the support core. Clamping the support core may include generating distinct pressures (e.g., equal or different pressures) in the different pressure zones.

[0042] If the operating side bearing is designed as a folding bearing, the method can further comprise the following step of pulling out the folding bearing, swinging it laterally and away from the roll device before pushing the sleeve to be removed from the support core into the sleeve exchange carriage.

[0043] The removed sleeves can be stored on a separate storage and shipping pallet.

[0044] A laser reference unit can be used to detect the actual sleeve position on the support core, thus ensuring that the embossed engravings on the upper and lower sleeves are precisely aligned. A laser detects the registration marks on the outer surface of the sleeve so that axial and radial adjustments can be performed automatically based on this information. For this purpose, the lower or upper support core can be moved axially by a motor, and the radial adjustment can be performed by a drive motor.

[0045] Furthermore, a quick core exchange can also be carried out: the entire support core can be replaced by another support core, for example one with a different diameter, or a solid roll. For this purpose, the entire drive train can be mounted on a separate console.

[0046] Exemplary embodiments of the present invention are described with the aid of the following figures. [Brief description of the drawings]

[0047] [Figure 1] 1 is a cross-sectional view of an exemplary embodiment of a sleeve changing calendar according to the present invention; [Diagram 2] FIG. 1 is a cross-sectional view through a roll of a sleeve changing calendar. [Diagram 3] FIG. 2 is a side view of a sleeve changing carriage disposed on a sleeve changing calendar according to the present invention; [Figure 4] FIG. 2 is a front view of a sleeve changing carriage disposed on a sleeve changing calendar. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] The sleeve change calendar 1 shown in FIG. 1 has an upper roll 12 and a lower roll 13 mounted on a roll frame 7. Between the two rolls a roll nip 19 is formed, between which an absorbent, preferably finely creped sanitary paper made of cellulose, such as a multi-ply tissue material, passes and can be embossed into a tissue web according to a predetermined pattern. The tissue material can be designed for use, for example, as toilet paper, kitchen paper, paper napkins or paper handkerchiefs. The rolls 12, 13 each comprise an expandable support core 3, on which a respective replaceable sleeve 4 is mounted, the outer surface 16 of which rolls against each other in the roll nip 19. The roll spacing 19 can be adjusted by mutually adjustable wedges 20, which can be adjusted by a fine screw thread, whereby the adjustment spindles can have different thread pitches. It can thus be provided that above a certain roll distance the spindles have a larger thread pitch than in the area where the roll nip 19 is smaller. To minimize vibrations, the roll frame 7 is equipped with vibration dampers 6. The vibration dampers 6 are respectively arranged between the roll frame 7 and the hydraulic cylinders 9 on which the slides 28 are supported. The rolls 12, 13 are hydraulically adjustable relative to one another, the upper roll 12 or the supporting core element 3 of the upper roll 12 is non-adjustably mounted in the roll frame 7 of the sleeve changing calender 1, and the lower roll 13 or the lower supporting core element 3 is mounted in a slide 28 provided in the roll frame 7, via which the lower supporting core element 3 can be hydraulically adjusted relative to the first supporting core element 3. The slide may be provided with a vertical linear guide with a sliding bearing, as shown. The bearings of the roll frame are provided on the drive side 25 and on the operating side 17 via triple bearings 21, whereby the stiffness of the shaft is increased. The bearing cooling devices 14 are arranged in the bearing covers, in particular around the bearing points, and it is provided that each supporting core bearing point is cooled separately.On the drive side, the rolls 12, 13 are driven in the opposite direction by a motor 25, which is connected to the rolls via a removable clutch 27. Furthermore, a gear is arranged between the motor 25 and the clutch 27, which can in particular be designed as an angle gear. The bearing 17 on the operating side is designed as a folding bearing, so that it can be axially removed from the shaft journal via a linear guide 18 and the bearing 17 can be pivoted laterally from the roll axis. This makes the sleeve exchange particularly simple and quick. This makes it possible to move the sleeve exchange carriage 24 axially towards the sleeve to be exchanged, so that the removed sleeve can be quickly pressed horizontally onto the support surface of the sleeve exchange carriage 24. A new sleeve can then be installed in the same way but in the opposite direction. The bearing 17 is then pivoted back and pressed back into the respective shaft journal via the linear guide 18. The desired bearing preload can then be set using a hydraulic clearance release. On the drive side, a multi-channel rotary feedthrough 23 is provided, via which individual pressures can be applied to different pressure zones 10 of one of the multi-chamber systems 11 provided in the support core. The pressure zones 10 are arranged axially spaced apart from one another, extend in an annular manner in the support core and are substantially parallel to the roll axis. Each pressure zone 10 is connected to a separate media channel 15. Detail E shown in FIG. 1 is an exemplary exaggerated detailed representation of the pressure curve in the roll nip 19, in which a cross section of a support core 3 with pressure zones 10 is shown. It can be seen that the various axially spaced pressure zones 10 are subjected to different pressures, so that the circumference D of the sleeve 4 stretched on the support core 3 changes in the axial direction, so that different pressures are set accordingly in the roll nip 19. The pressure zones 10 can in particular be designed in such a way that pressure zones 10 of uniform dimensions are located opposite one another on the upper roll 12 and on the lower roll 13.To rotationally align the upper roll 12 and the lower roll 13 with respect to one another, the sleeve changing calendar 1 further comprises, in the embodiment shown, a laser reference unit 5 which scans the lower roll 13 from below and the upper roll 12 from above in order to measure the respective alignment of the marks provided on the sleeves. To correct the alignment, the two rolls 12, 13 can be rotated relative to one another until the marks are exactly aligned in position.

[0049] FIG. 2 shows a cross-section of one of the rolls of the sleeve changing calendar 1, namely the upper roll 12 or the lower roll 13. In this figure, a multi-chamber system 11 is shown, which comprises a number of pressure zones 10 in the axial direction of the rolls 12, 13, which are formed over the circumference of the support core 3 and serve to create a frictional connection between the support core 3 and the sleeve 4 axially pressed onto it. The illustrated embodiment shows four pressure zones 10, which may each have the same width and preferably extend uniformly over the entire width of the roll. Each pressure zone 10 thus has a width that extends axially over a portion of the roll 12, 13. Moreover, each pressure zone 10 is formed annularly in the tangential direction of the support core 3, so that the pressure acting on the sleeve 4 is uniform over the circumference. Each pressure zone 10 has a separate fluid supply, and each fluid channel 15 has a first portion 15.1 extending axially through the support core and a second portion 15.2 branching radially vertically from the first portion 15.1 and leading to the corresponding pressure zone 10 assigned to each fluid channel 15.

[0050] Preferably, the sleeve change calendar 1 has a three-part structure with a central support core 3 onto which a first zone sleeve with pressure zones 10 is pressed, i.e. shrunk. An exchangeable sleeve 4 with circumferential engravings 8 is pressed onto its periphery. The pressure zones 10 are formed as recesses on the inside of the zone sleeve facing the support core 3. At least one of the fluid channels 15 leads into each of the recesses.

[0051] FIG. 3 shows a side view of the sleeve exchange carriage 24 arranged on the sleeve exchange calendar 1 according to the invention. In the example shown, the sleeve 4 is in the process of being pulled out of the support core 3 of the upper roll 12, and the sleeve 4 is pushed horizontally onto the upper sleeve receiving device 29 of the sleeve exchange carriage 24. To replace the sleeve 4, the sleeve receiving device 29 is moved towards the sleeve exchange calendar 1 so that the upper surface of the receiving device 29 for receiving the sleeve 4 is flush with the upper surface of the support core 3 of the roll 12, 13 to be replaced. To remove the sleeve 4, the sleeve exchange carriage 29 can be equipped with a motor-driven removal device, for example several drive rolls, which can move the sleeve horizontally. The sleeve exchange carriage 24 is provided with two sleeve receiving devices 29 arranged vertically one above the other, so that the sleeve exchange carriage 24 can receive the sleeve 4 of both the upper roll 12 and the lower roll 13 at once. The sleeve receiving device 29 can be mounted on the sleeve exchange carriage 24 in a height-adjustable manner. This allows the sleeve receiving devices 29 to be moved one after the other to the aligned transfer position with the sleeve 4 to be removed. Alternatively, it can be provided that the vertical distance between the sleeve receiving devices 29 is set in such a way that when the sleeve changing carriage 24 approaches the sleeve changing calendar 1, both sleeve receiving devices 29 are already aligned with the respective support core 3. The sleeve changing carriage 24 has a chassis 30 with rollers 31, on which is mounted a holding frame 32 to which the sleeve receiving devices 29 are fixed.

[0052] FIG. 4 shows a front view of the sleeve exchange carriage 24, which is arranged at the end of the sleeve exchange calendar 1 on the operator side during the sleeve exchange process. It can be seen that the bearing 17 on the operator side is axially withdrawn from the support core 3 and is laterally, i.e. radially, displaced via a horizontal linear guide 33, allowing the sleeve to be exchanged. The horizontal linear guide 33 is attached to the roll frame 7. In particular, it can be provided that the sleeve exchange carriage 24 and / or the sleeve exchange calendar 1 are provided with a positioning device, by means of which the sleeve exchange carriage 24 can be positioned on the sleeve exchange calendar 1 in a self-centering manner, so that as soon as the sleeve exchange carriage 24 moves towards the sleeve exchange calendar 1, the sleeve exchange can be performed. As shown in FIG. 4, the sleeve receiving device 29 is attached to the sleeve exchange carriage 24 so that it can be adjusted both in height and in the lateral direction. It can be provided that the holding frame 32 is movable relative to the chassis 30. It can also be provided that the sleeve exchange carriage 24 comprises two or four sleeve receiving devices 29. In an embodiment with four sleeve receiving devices 29, it is possible to bring in two new sleeves 4 for sleeve exchange, therefore first the sleeve 4 to be exchanged is removed and then the sleeve receiving device 29 is adjusted laterally on the sleeve exchange carriage or the sleeve exchange carriage 24 is moved laterally in order to pull the sleeve 4 to be pulled onto the support core 3.

[0053] The features of the invention disclosed in the above description, in the drawings and in the claims may be essential for the implementation of the invention both individually and in any combination. [Explanation of symbols]

[0054] 1 Sleeve Exchange Calendar 3 Support Core 4 Sleeve 4.1 Zone sleeve 5 Laser Reference Unit 6. Vibration damper 7 Roll Frame 8. Engraving 9 Hydraulic Cylinder 10 Pressure Zones 11 Multi-chamber system 12 Upper roll 13 Lower roll 14 Bearing cooling 15 Media Channels 16 External surface 17 Operating side bearing 18 Linear guide 19 Roll Nip 20 Wedges 21 Triple Bearing 23 Rotary Feedthrough 24 Sleeve exchange carriage 25 Drive motor / drive side 27 Clutch 28 Slides 29 Sleeve holding device 30 Chassis 31 Roller 32 Support frame 33 Linear guide D Sleeve outer diameter Exaggerated detail of the pressure curve of the E-roll nip

Claims

1. A sleeve changing calender (1) for rotary embossing a multi-ply tissue web (2) or for producing ply bonds between individual plies of said multi-ply tissue web (2), comprising: The sleeve exchange calendar (1) comprises a roll frame (7) on which at least one roll (12, 13) is mounted, and the roll frame (7) is fitted with an expandable support core (3) and an exchangeable sleeve (4), The sleeve (4) can be pressed into the support core (3) for assembly and can be fixed to the support core (3) with a friction fit; characterised in that the support core (3) is designed with a multi-chamber system (11) for applying pressure individually to separate pressure zones (10), The sleeve change calendar (1).

2. 2. A sleeve changing calendar (1) according to claim 1, wherein the pressure zones (10) can each be subjected to an individually adjustable pressure, thereby making it possible to produce different embossing zones in a selective and / or spatially resolved manner, the pressure zones (10) being divided along the axial direction of the rolls (12, 13).

3. 3. The sleeve changing calendar (1) according to claim 1 or claim 2, wherein the outer diameter (D) of the sleeve is partially adjustable in a pressure-controlled manner via hydraulic pressure which is separately adjustable in the individual pressure zones (10) of the support core (3).

4. The sleeve changing calendar (1) according to any one of claims 1 to 3, wherein the support core (3), in particular the first support core element (5), has at least one rotary feedthrough (14) for transmitting hydraulic oil.

5. 5. The sleeve changing calendar (1) according to claim 4, wherein the pressure zone (10) or the hydraulic cylinder (9) assigned to the pressure zone (10) can each be subjected to pressure via a separate media channel (15) connected to the at least one rotary feedthrough (14).

6. A sleeve changing calendar (1) according to any one of claims 1 to 5, wherein the support core (3) is conically ground on its outer surface and / or coated with a highly wear-resistant material.

7. The sleeve changing calendar (1) according to any one of claims 1 to 6, wherein the sleeve (4) is made of high strength tool steel and / or has an engraved surface.

8. The sleeve changing calendar (1) according to any one of claims 1 to 7, wherein the support core (3) is attached to the roll frame (7) at three locations.

9. Sleeve changing calendar (1) according to any one of the preceding claims, wherein the support core bearings are conditioned via bearing cooling (21), in particular by cooling all support core bearing points.

10. The sleeve changing calendar (1) according to any one of the preceding claims, wherein the drive side bearing (17) is rigidly mounted in the roll frame (17) or in the slide (8).

11. 11. The sleeve changing calendar (1) according to any one of claims 1 to 10, wherein the operator side bearing (17) is designed as a folding bearing and / or the operator side roll bearing (17) is openable and closable via linear guides (18) and / or ball bushes.

12. The sleeve changing calendar (1) according to any one of claims 1 to 11, comprising an upper roll (12) and a lower roll (13), the center offset of the upper roll (12) relative to the lower roll (13) being adjustable.

13. The sleeve changing calendar (1) according to any one of claims 1 to 12, further comprising an active nip control, whereby the adjustable pressure in the roll nip (19) can be selectively controlled for the different pressure zones.

14. 14. A sleeve changing calendar (1) according to claim 12 or 13, wherein the nip (19) between the upper roll (12) and the lower roll (13) is adjustable by means of a threaded spindle with a fine thread, which preferably adjusts an adjustable wedge (20) forming the nip (19).

15. 14. The sleeve changing calendar (1) according to claim 12 or 13, wherein the nip (19) between the upper roll (12) and the lower roll (13) is further adjustable by at least two single-acting or double-acting hydraulic cylinders (9) for opening and closing the roll nip (19).

16. A sleeve change calendar (1) according to any one of claims 1 to 15, comprising at least one laser reference unit for detecting the position of the sleeve on the support core (3), the detection of the position of the sleeve on the support core (2) being carried out by means of at least one detectable reference point arranged on the sleeve surface.

17. 16. A sleeve change calendar (1) according to claim 15, wherein the embossed engravings (8) of the upper roll (12) and the lower roll (13) can be aligned with respect to one another via the at least one laser reference unit, the reference points on the outer surface of the sleeve can be detected via the laser, and the corresponding axial and / or radial adjustment of the rolls (12, 13) relative to one another is performed via a motor-driven axial adjustment and / or a drive motor-driven radial adjustment of at least one of the support cores (3).

18. The sleeve changing calendar (1) according to any one of the preceding claims, wherein the roll frame (7) is designed in a closed structure and has a side stand with a welded cross member and integrated vibration damping components.

19. An apparatus comprising a sleeve changing calendar (1) according to any one of claims 1 to 18 and a sleeve changing carriage (24) designed to push a sleeve (4) into the support core (3) or to push the sleeve (4) out of the support core (3).

20. A method for replacing a sleeve (4) on a sleeve changing calendar (1) according to any one of claims 1 to 18, comprising the steps of: - positioning the front face of a movable sleeve changing carriage (24) against said calendar (1); - loosening said support core (3); - pushing the sleeve (4) to be removed from said support core (3) into said sleeve exchange carriage (24); - pushing the sleeve (4) to be mounted from said sleeve exchange carriage (24) onto said support core (3); The method comprising the steps of:

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