Machine and method

Abstract

The invention relates to a machine for producing or processing a fibrous web, comprising a Yankee cylinder for drying and / or smoothing a fibrous web and a transfer roller which can be arranged next to the Yankee cylinder while forming a transfer nip, the machine further comprising a marking roller which is arranged next to the Yankee cylinder while forming a transfer nip, the marking roller can be arranged next to the Yankee cylinder while forming a marking nip, the marking nip being arranged downstream of the transfer nip as viewed in the running direction of the fibrous web, and the machine having a roller shell, in particular a marking mat, the roller sleeve is arranged in the form of a roller sleeve ring around the marking roller and is guided through the marking nip. According to the invention, the marking roller and the preferably transfer roller are designed as deflection compensation rollers.

Description

[0001] The invention relates to a machine for producing or processing a fibrous web, in particular for producing glossy paper (MG paper), and to a method for replacing a roller cover of a machine for producing or processing a fibrous web.

[0002] The paper machine concept using MG cylinder + hot air valve cover as a central drying device is used to produce special paper with smooth one side and high specific volume at the same time. Such a paper machine is known, for example, from the document DE 102017118218A1 and the document DE102017118222A1. This is usually called a heated large MG cylinder, also known as a Yankee cylinder. In the scope of this application, these two terms are used synonymously.

[0003] By applying the moistened paper web to the hot MG cylinder, a very high gloss and smoothness can be produced on the bottom side of the paper web. This is associated with a higher specific volume of the paper, since, unlike in a calender, the gloss and / or smoothness is not produced in the calender nip by compression of the paper due to high linear loads.

[0004] When MG paper is used in packaging (e.g. bread bags), in addition to the high gloss on one side, it may be necessary to set a special line pattern with a purely visual function on the paper surface. There are already many different types of patterns on the market.

[0005] These special lines can be realized by means of a press, usually in combination with a marking felt at the inlet of the MG cylinder, since there the paper web has an ideal moisture content in the range of 40-58%, thereby making it possible to produce a visual contrast.

[0006] To date, these lined papers have been produced on old, slow-running, narrow-web MG machines of approximately 4 meters in width.

[0007] It would of course be desirable to be able to carry out the described marking with the aid of marking felts for new, high-speed and wide-format MG systems, or to be able to produce the described products on these systems under economically favorable conditions.

[0008] It has surprisingly proven difficult to provide very high production capacities with these wide, fast machines. Although previous machines can be used to great extent for such textures with lines, in modern machines, textures with lines usually only account for a certain small part of the total production. In addition, there can be a large number of different marking patterns, each of which requires its own marking felt. Therefore, the types are frequently changed during production.

[0009] The object of the present invention is to propose a machine by which special papers can be produced reliably even with a large machine width.

[0010] The object of the present invention is also to propose a machine which can be operated economically even with a small production volume of individual types and with frequent changes of types during production.

[0011] The technical problem to be solved by the present invention is also to design the machine in such a way that a wide roller sleeve, for example a marking felt with a width of up to 9 m, can be pressed selectively (startable / stoppable) onto the paper web on the MG cylinder, and the felt replacement time must be as short as possible.

[0012] This makes it possible, in particular, to increase the overall equipment efficiency of new paper machines.

[0013] This object is achieved by a machine as claimed in independent claim 1 and a method for changing a roller shell as claimed in independent claim 9. Advantageous embodiments are described in the dependent claims.

[0014] In terms of the machine, the technical problem is solved by a machine for producing or processing a fibrous web, the machine comprising a Yankee cylinder for drying and / or smoothing the fibrous web and a transfer roller which can be arranged next to the Yankee cylinder while forming a transfer nip. The machine also comprises a marking roller which can be arranged next to the Yankee cylinder while forming a marking nip, wherein the marking nip is arranged after the transfer nip as viewed in the running direction of the fibrous web.

[0015] The machine furthermore has a roller shell, in particular a marking felt, wherein the roller shell is arranged in the form of a roller collar around the marking roller and is guided through the marking nip.

[0016] According to the invention, it is provided that the marking roller and preferably the transfer roller are designed as deflection compensation rollers.

[0017] The fibrous web is typically a paper web, such as an MG paper web.

[0018] In the scope of this application, the term roller cover and felt or marking felt are used synonymously, because marking felt is the most common application associated with marking rollers so far. However, it is also feasible to use fabric, film or other suitable roller covers instead of marking felt.

[0019] The Yankee cylinder for use within the scope of the invention can be, for example, a casting cylinder. However, it is also particularly advantageous to use a Yankee cylinder with a steel casing.

[0020] The Yankee cylinder is usually heated from the inside with hot steam at a certain pressure. This causes the Yankee cylinder to deform. The cylinder seems to be blown up. This effect is particularly noticeable at the edge of the Yankee cylinder on the operator side or drive side. Although the outer shell is greatly deformed outwards, the end cover remains essentially unchanged. The surface of the Yankee cylinder therefore has a large gradient in this edge area.

[0021] For example, the document EP 3 974 576 A1 discloses the use of so-called deflection-compensated rollers in combination with Yankee cylinders as transfer rollers. Compared to conventional cylindrical rollers or rollers with a fixed crown, deflection-compensated rollers can adjust the properties of the marking nip over the entire width and thus the properties of the contact force in a targeted manner. Deflection-compensated rollers are also called bend-compensated rollers. Anmeldering sells such rollers under the brand name NipCo rollers.

[0022] The fibrous web can be transferred to the Yankee cylinder expediently in the region of a bend compensation roller arranged next to the Yankee cylinder, thereby achieving a uniform pressing of the web on the Yankee cylinder, especially in the region of the edges, and a stable transfer of the web to the Yankee cylinder.

[0023] According to the invention, so-called deflection compensation rollers are also used as marking rollers, in particular. Such deflection compensation rollers are also called bending compensation rollers or NipCo (NipCorrect) rollers.

[0024] The wider the Yankee cylinder, the more severe the deformation phenomena on the surface of the Yankee cylinder. Furthermore, the wider the Yankee cylinder, the greater the risk that the pressing force of the roller or roller cover (especially the marking felt) on the paper web will be different over the width of the fiber web when using a conventional roller as a marking roller, which can lead to uneven marking on the paper web. Compensation by generally increasing the contact pressure is undesirable, since this can lead to excessive compression of the web at other locations and affect the specific volume of the web. With the aid of a deflection-compensating roller, the marking nip can be controlled in a targeted manner, so that the marking pattern of the fiber web can be adjusted appropriately. In particular, the use of a deflection-compensating roller as a marking roller is very advantageous for Yankee cylinder widths of 6 m and above, in particular 7 m, 8 m or 9 m and above.

[0025] Since the machine should be optimized for frequently changing assortments, it is also advantageous to use a deflection-compensated roller as marking roller. The steam pressure in the Yankee cylinder is different for different assortments during machine operation, which leads to significantly different deformations. These can be compensated with the aid of the deflection-compensated roller, thus ensuring a uniform nip and a uniform marking pattern on the fiber web.

[0026] It is usually expedient if the machine has a transport roller shell for transporting the fibrous web to the Yankee cylinder, wherein the transport roller shell is guided together with the fibrous web through the transfer nip.

[0027] In an advantageous embodiment, at least one, in particular all, of the deflection compensation rollers may include a rotatable casing made of a fiber composite material, in particular a glass fiber reinforced plastic casing, which in particular has an outer coating made of polyurethane. Glass fiber reinforced plastic is a material made of plastic and glass fibers.

[0028] In this case, for example, the pressing can be achieved by means of a bending compensation roller having an elastic material consisting of a glass fiber reinforced composite material, such as a NipcoFullFlex roller having a convex support source, or by means of a shoe pressure roller, such as the NipcoFlex-T roller used in tissue machines, i.e. a shoe pressure roller having a concave pressure shoe with a QualiFlex outer cover.

[0029] For example, a deflection-compensating roller with a composite casing, such as a so-called Nipco FullFlex roller, can be used as a deflection-compensating roller with an elastic casing, which is significantly more flexible than a steel casing or a cast casing and can therefore better conform to the contour of the Yankee cylinder. Such a roller is also lifted from a shoe roller by using a plurality of convex supporting sources arranged side by side, usually closely spaced, over the length of the roller (or the width of the machine) instead of a concave shoe. Such a casing consists of a carbon fiber reinforced plastic casing or a glass fiber reinforced plastic casing with an outer coating of polyurethane. Such a casing is more flexible than a steel casing or a cast casing and can therefore better adapt to the changing contour of the Yankee cylinder. By means of such a pressure roller (marking roller and / or transfer roller) arranged on the Yankee cylinder, good adaptation to the respective Yankee cylinder deformation, a uniform linear pressure profile in the transverse direction and uniform quality properties with respect to thickness, smoothness and gloss are produced.

[0030] Therefore, in a preferred embodiment, two deflection compensation rollers can be arranged on the Yankee cylinder in separate, independent roller sleeves. The first of the two rollers should be called a "transfer roller" and the second roller should be called a "marking roller". A cantilever bracket can be placed in each roller sleeve.

[0031] The bow compensation rollers are ideally adapted to the respective crown conditions of the Yankee cylinder which are caused by the different steam pressures in the Yankee cylinder.

[0032] The task of the first deflection compensation roller, including a possibly associated protective felt ring, is to transfer the paper web to the MG cylinder and to fix it there uniformly in the CD direction (ie cross-machine direction).

[0033] The second bow-compensating roller, which is located behind the first bow-compensating roller in the running direction, produces a marking, for example a line impression, on the surface of the paper web by means of its own circumferential marking felt.

[0034] The second nip, referred to as the marking nip, can also be selectively deflected or moved back, thereby enabling the production of a paper web without line markings.

[0035] Quick and damage-free replacement of felt

[0036] Since the production of corresponding marked paper, in particular paper with lines, can be small, the marking felt is usually not worn out when the felt is replaced. Therefore, it is economically and ecologically disadvantageous to cut up or discard the old marking felt when the felt is replaced, as is common. It is desirable to reuse these felts during the next production of the corresponding type. Therefore, the present invention is also aimed at a non-destructive felt replacement concept.

[0037] In order to solve these technical problems, the inventors have proposed different concepts, which are creative both independently and in combination with each other.

[0038] In order to be able to produce additional different embossing patterns and to be able to quickly change the embossing pattern, a special changeover concept for the marking felt was developed, which consists of the following elements:

[0039] - Use of a deflected marking roller that can be removed from the machine as a bending compensation roller

[0040] - cantilever brackets that enable the use of continuous felt

[0041] -Automatic storage system for tensioning rollers

[0042] -Felt changing solution including 2-drawer changing rack.

[0043] As a result, the marking felt located in the machine can be removed from the machine without damage (without the usual cutting process) in order to be able to use it again in a subsequent production.

[0044] Furthermore, a new marking felt can be inserted very quickly, so that production can be restarted with a new pattern after a changeover time of 30 to 90 minutes.

[0045] It is important in terms of safety that the marking felt cannot be replaced during operation of the MG section, so the duration of the felt replacement is crucial to the efficiency of the equipment. Several concepts have been proposed for this purpose.

[0046] Concept 2.1 Removal device for marking rollers, including hydraulic cylinders for roller positioning and locking the removal device

[0047] In an advantageous embodiment, it can be provided that the machine comprises a removal device in order to move the marking roller laterally out of the machine.

[0048] In particular, it can be provided that the removal device comprises a removal rail and a removal carriage which is connected to the marking roller, wherein the removal carriage can be moved along the removal rail and can be removed from the machine together with the marking roller.

[0049] Furthermore, it is advantageous if at least one lifting element is provided for pivoting the marking roller towards or away from the Yankee cylinder, the lifting element being connected to the marking roller and a table part of the machine, wherein the lifting element is designed to be decoupled from the marking roller and / or the table part.

[0050] It is particularly advantageous if the lifting element comprises a hydraulic cylinder or consists of a hydraulic cylinder.

[0051] The marking roller can be moved, for example, by means of a fixed integrated device without a crane device to the operator-side area of ​​the machine. The marking roller can be decoupled from other machine parts, such as hydraulic cylinders, rotary bearings, etc., and can be moved out of the machine as a whole by means of a traction device (manually or automatically). There, the crane can completely lift the entire roller in one process.

[0052] It can be provided that the marking roller is connected or can be connected to the removal carriage. The removal carriage can be guided in a removal rail and removed from the machine together with the marking roller. A possibly necessary alternative "marking roller" can also be fastened to the removal carriage, which is also the insertion carriage, and replaced in the removal rail.

[0053] Advantageously, a lifting element can be provided for pivoting the marking roller towards and away from it. Such a lifting element is usually connected both to the marking roller and to the machine table. The lifting element can be decoupled from the roller or the machine table in order to change the marking felt and to move the marking roller out and in. The lifting element can be designed, for example, as a hydraulic lifting cylinder and can be decoupled from the marking roller. When the roller is moved out together with the removal carriage, the lifting element can remain in the machine at the machine table.

[0054] Cantilever solution for the machine in this position

[0055] The cantilever and the machine table of the Yankee cylinder can be designed so that the two roller sleeve guides (felt / screen) can be arranged one above the other, for example with integrated bending compensation rollers. For the operation of the felt / screen arranged below, an additional cantilever bracket (support of the main cantilever bracket) can be installed.

[0056] Concept 2.2 Automatic storage system for tensioning rollers without crane

[0057] It is also advantageous if the machine comprises a tensioning roller, wherein a roller collar is arranged around the marking roller and the tensioning roller and is guided through the marking nip, and wherein means are provided in the machine for moving the tensioning roller from a working position into a maintenance position.

[0058] With the aid of a rotatable or translatable device, the tensioning roller in the roller collar can be brought into storage. This is achieved without the aid of a crane. This is advantageous because the crane can be used for other work in the meantime. This means that during the entire process of changing the felt / screen, important downtimes can be minimized or omitted. This is particularly important because paper machine workshops are usually only provided with one workshop crane, and the availability or unavailability of this crane has a decisive influence on the duration of the maintenance shutdown.

[0059] The maintenance position of the tensioning roller is selected here so that when the tensioning roller is in the maintenance position, the roller sleeve of the marking felt is not in a tensioned state. This lack of tension is a prerequisite for removing or removing the marking felt from the machine without damage.

[0060] Roller sleeve replacement

[0061] Furthermore, a method for replacing a roller cover of a machine for producing or processing a fibrous web is proposed, the machine comprising a Yankee cylinder for drying and / or smoothing the fibrous web and a transfer roller which can be arranged next to the Yankee cylinder while forming a transfer nip, wherein the machine further comprises a marking roller which can be arranged next to the Yankee cylinder while forming a marking nip, wherein the marking nip is arranged downstream of the transfer nip as viewed in the running direction of the fibrous web.

[0062] The machine also includes a roller sleeve, in particular a marking felt, and a tensioning roller, wherein the roller sleeve is arranged in the form of a roller sleeve around the marking roller and the tensioning roller and is guided through the marking nip. Means for moving the tensioning roller from a working position to a maintenance position are also provided in the machine.

[0063] Furthermore, at least one lifting element is provided for pivoting the marking roller towards or away from the Yankee cylinder, the lifting element being connected to the marking roller and a table part of the machine, wherein the lifting element is designed to be decoupled from the marking roller and / or the table part.

[0064] The marking roller and / or the transfer roller can be designed as a deflection compensation roller. However, this is not necessary for the method of changing the roller cover. The method is also well suited for machines in which the marking roller and / or the transfer roller is designed as a conventional roller, for example a convex roller, in particular a roller with a negative projection.

[0065] The method here comprises the following steps:

[0066] a. moving the tension roller from the working position to the maintenance position,

[0067] b. decoupling the lifting element from the marking roller and / or the machine component,

[0068] c. providing a first replacement unit for accommodating the roller ring,

[0069] d. Transferring the roller collars from the machine to the first changing unit.

[0070] In a preferred design, the method may further include the following steps:

[0071] e. providing a second replacement unit, on which a second roller ring is mounted,

[0072] f. transferring the second roller collar from the second replacement unit to the machine so that the second roller collar is arranged around the marking roller and the tensioning roller,

[0073] g. coupling the lifting element to the marking roller and / or the table component,

[0074] h. Move the tensioning roller from the maintenance position to the working position.

[0075] The felt / screen changing unit is provided for being able to change the felt / screen quickly. The changing unit can be designed to be constructed along the screen ring in the machine by means of the guide rail (support rail) of the prescribed position.

[0076] In an alternative embodiment of the method, it can be provided that method steps c. and d. are carried out as follows:

[0077] c. providing a first replacement unit for accommodating a roller collar, wherein the second roller collar is mounted on the first replacement unit,

[0078] d. Transferring the roller ring from the machine to the first changing unit, wherein the roller ring is in particular placed on the second roller ring.

[0079] In an advantageous embodiment, it can be provided that the method further comprises the following steps:

[0080] f. transferring the second roller collar from the first replacement unit into the machine so that the second roller collar is arranged around the marking roller and the tensioning roller, wherein the first roller collar in particular remains on the replacement unit,

[0081] g. coupling the lifting element to the marking roller and / or the table component,

[0082] h. Move the tensioning roller from the maintenance position to the working position.

[0083] By this variant of the method, the roll shell can be removed from the machine and the second roll shell can be moved into the machine by a single changing unit. No second changing unit needs to be provided and no moving these changing units back and forth is required, which further speeds up the changing of roll shells.

[0084] For this feature of the method, the roll cover is placed on the second roll cover on the first changing unit when it is removed from the machine. If one or both roll covers have a rough surface, this may prove to be difficult or laborious.

[0085] It is therefore advantageous if a sliding layer is arranged between the roller ring and the second roller ring, wherein the roughness of the upper side and the lower side is in particular smaller than that of the roller ring and the second roller ring, thereby making it easier to remove the roller ring from the machine and to insert the second roller ring into the machine.

[0086] The sliding layer can be, for example, a polymer film or a smooth polymer tape.

[0087] Suitably, the sliding layer with the second roller sleeve can be mounted on the corresponding replacement unit while the machine is still running, thereby preventing the downtime of the machine from being increased due to the provision of the sliding layer.

[0088] It is also advantageous to design the first and / or second changing unit as a mobile changing unit that can be moved, for example, by a workshop crane. This allows the felt / screen to be quickly moved out to an empty changing unit docked with the workshop crane. The same applies to the insertion of the felt / screen by means of the docked second changing unit with the second roller collar that is loaded with the felt / screen.

[0089] Advantageously, provision can be made here for such a mobile replacement unit to have a bolt and for the machine to have a receptacle for the bolt and for the first replacement unit and / or the second replacement unit to be positioned during provision in such a way that the bolt is introduced into the receptacle.

[0090] The mobile replacement unit can be designed with a pin (= latch) so that it can be moved into a structurally adapted boom bracket on the end side on the operator side. This avoids the original protruding pin on the boom and also makes it easier to approach the machine in this area on the operator side.

[0091] Advantageously, two mobile change units of the same type are provided. This allows the new second roller cover (felt / screen) to be put on to the first change unit before the machine is shut down. After the roller cover has been removed from the machine and put on the first change unit during the shutdown, the second change unit can be docked on the boom immediately and the new second roller cover can be moved into the machine. In this way, the roller cover change can be further accelerated.

[0092] The latch can be designed, for example, to be round, which makes docking of the replacement unit easier.

[0093] However, the latch can also be designed to be non-circular (rectangular, triangular, etc.), thereby ensuring that the replacement unit is always optimally positioned after docking.

[0094] Alternatively, it can be provided that the first replacement unit is designed as a fixed replacement unit. As a part of the replacement unit, it can be provided, for example, that a plurality of guide rails and / or cable guides are fixed on the machine table and, if necessary, a support is fixed.

[0095] These rails or cable guides can be installed on the operator side of the machine while the machine is still running.

[0096] Likewise, the second roller shell can already be mounted on the stationary changing unit. It is also possible to mount the sliding layer on the stationary changing unit. All this can be prepared while the machine is still running. Furthermore, all these preparations can be carried out without a workshop crane. This is in contrast to the use of mobile changing units, which usually require a workshop crane to transport due to their greater weight. During the installation of the stationary changing unit, the workshop crane can be used for other activities.

[0097] Furthermore, it is possible, for example, that the machine is part of a larger machine for producing a fibrous web, in particular a paper or cardboard web, which has a headbox, a forming unit, a press section, a predrying section, the MG smoothing Yankee cylinder and a winding section, wherein the predrying section is designed in particular for unilateral predrying of the bottom side of the fibrous web, for example an upper MG smoothing Yankee cylinder is provided as an MG smoothing Yankee cylinder, with which the bottom side of the fibrous web is in contact.

[0098] A remoistening device can be provided after the predrying section along the web running direction (L) and before the fibrous web runs to the MG smoothing Yankee cylinder to remoisten the bottom side of the fibrous web on one side and form a moisture gradient along the Z direction of the fibrous web toward the bottom side of the fibrous web accordingly.

[0099] However, according to various aspects of the present invention, the machine may also have other application possibilities.

[0100] The invention is explained below with reference to the schematic drawings. However, the invention is not limited to the embodiments shown.

[0101] Figure 1 A machine according to one aspect of the invention is shown,

[0102] Figure 2 A machine according to another aspect of the invention is shown,

[0103] Figure 3 A machine according to another aspect of the invention is shown,

[0104] Figure 4 A machine according to another aspect of the invention is shown,

[0105] Figure 5a , 5b and 5c show a mobile replacement unit according to other aspects of the invention,

[0106] Figure 6a , 6b , 6c and 6d show the steps of replacing the roller sleeve by a fixed replacement unit according to other aspects of the present invention.

[0107] Figure 1 The present invention shows a section through a machine for producing a special paper web, for example a machine for producing so-called glossy paper (MG paper). An important component of such a machine is a large cylinder 1, which is usually heated by steam and is called a Yankee cylinder or MG cylinder. The paper web, which usually has a moisture content in the range of 40% to 58%, is transported from a transport roller shell 8 to the Yankee cylinder 1 and is transferred to the Yankee cylinder 1 in a transfer nip 4. The transfer nip 4 consists of the Yankee cylinder 1 and a transfer roller 2, which is arranged next to the Yankee cylinder 1. In particular, for wide machines with a width of, for example, 6 m or more, it is advantageous to design the transfer roller 2 as a deflection compensation roller. In accordance with Figure 1 In the design scheme, the marking nip 5 is arranged after the transfer nip 4 along the running direction of the paper web or along the rotation direction of the Yankee cylinder 1. The marking nip 5 is composed of the Yankee cylinder 1 and the marking roller 3, and the marking roller 3 can be placed next to the Yankee cylinder 1 to form the marking nip 5.

[0108] The machine also has a roller sleeve 7 which is usually designed as a marking felt 7. The marking felt 7 is guided in the form of a roller sleeve around the marking roller 3 and the tension roller 6 and optionally further guide rollers and thus runs through the marking nip 5 together with the paper web. Figure 1 Here, the tensioning roller 6 is shown in the working position 6a, whereby the roller cover 7 is in suitable tension. In addition, a maintenance position 6b, such as a suitable storage position, is provided. If the tensioning roller is in the maintenance position 6b, the fabric is not in tension, so that the roller cover can be replaced.

[0109] The paper web is smoothed here on the side facing the Yankee 1 and given a certain glossiness. In order to maintain the specific volume of the paper, this smoothing is carried out without conventional calendering.

[0110] When using a corresponding marking felt 7, the paper web is marked, for example in the form of a line, in the marking nip 7 on the side facing the Yankee cylinder 1. It is important that the marking nip 3 is distributed very evenly over the entire width of the machine, despite the deformation of the Yankee cylinder 1 due to the action of the steam, otherwise uneven marking of the paper would occur, which would lead to increased waste in the worst case. Therefore, in many machines according to aspects of the invention, the marking roller 3 is designed as a deflection compensation roller.

[0111] In particular, a deflection compensation roller with a composite casing can be used as a deflection compensation roller. Such a casing consists of a CFK (carbon fiber reinforced plastic) casing or a GFK (glass fiber reinforced plastic) casing with an outer coating made of polyurethane. Such a casing is more flexible than a steel casing or a cast casing and can therefore be better adapted to the changing contour of the Yankee cylinder. By means of such a marking roller 3 (and / or transfer roller 2) arranged on the Yankee cylinder 1, a good adaptation to the respective Yankee cylinder deformation, a uniform linear pressure profile in the transverse direction and uniform quality properties with respect to thickness, smoothness and gloss are produced.

[0112] In an advantageous design, both the marking roller 3 and the transfer roller 2 can be designed as deflection compensation rollers, and in particular both can have a composite outer cover as described above. The Nipco FullFlex roller from Anmeldering is particularly suitable for this.

[0113] Figure 2 Still shows Figure 1 The present invention relates to a machine of the present invention, but the focus is on the details of the marking roller 7. The machine also includes two cantilevers 11, 12, which are used for each roller shell 7, 8. On the cantilever 11 corresponding to the felt 7 or the marking roller 3, a removal rail 20 extending in the transverse direction of the machine is installed. A removal bracket 21 is guided in the removal rail 20. The marking roller 3 is fixed on the removal bracket 21. This makes it easier to replace the marking roller 3, because the marking roller can be easily removed and removed along the removal rail 20, for example, in the direction of the operator side FS of the machine. The same marking roller 3 or an alternative roller can then be fixed on the removal bracket 21 and placed in the machine again with the help of the removal rail 20.

[0114] Figure 2Also shown is a lifting element 20, which is used to place or move the marking roller 3 next to the Yankee cylinder 1. The lifting element 20 is designed as a hydraulic lifting cylinder 20, which is connected to both the marking roller 3 (or its bearing) and the machine table component. In order to fully utilize the above advantages of the removal device, Figure 2 The lifting element 20 is designed to be decoupled from the marking roller 3. When removing or replacing the marking roller 3, the decoupled lifting element 22a is left on the machine table. Therefore, the lifting element can be used for roller positioning and also for locking the removal device.

[0115] Figure 3 It also shows Figure 1 and Figure 2 A machine of the type shown. A variant is shown here in which the tensioning roller 6 can be moved from the working position 6a into the maintenance position 6b without the use of external auxiliary means such as a workshop crane. This can be achieved by a translational or rotational movement, which can be achieved, for example, along suitable rail elements. This feature makes a significant contribution to speeding up the replacement of the roller shell 7, since the use of a crane, which is a scarce resource, is avoided here.

[0116] Figure 4 A machine is shown, the machine table of which has at least four arms 11, 12, 13, 14. So-called intermediate pieces 15 are provided between the arms 11, 12 or between the arms 11, 12 and other machine table components. If, for example, the marking felt 7 is to be replaced, the intermediate piece 15 adjacent to the arm 11 can be removed and the marking felt can be moved in or out through the resulting opening.

[0117] Figure 5a , 5b 5 c describe the method according to a further aspect of the invention in more detail and explain the advantageous use of mobile change units 25 , 26 .

[0118] Figure 5a The side view of a changing unit 25 is shown, which is suspended from a workshop crane at a holding element. A support element extends centrally, at the front end of which a latch 28 is provided. The changing unit has guide rails 28 at least above and to the sides of the support element. When changing the roller shell, the roller shell is placed on these guide rails 28.

[0119] Figure 5b A front view of such a change unit 25, 26 is shown. Here, the marking felt 7 is already placed on the change unit 25, 26 and is located on the guide rail 28. This may be, for example, the second change unit 26, on which an alternative marking felt 7 is placed and which is then moved into the machine.

[0120] like Figure 5c As shown, the latch 27 can be introduced into a corresponding receptacle on the end face of the boom 11 on the operator side FS. Figure 5a-5c In the example of , the latch 27 is designed as a round, cylindrical or slightly conical latch 27. This makes it easier to introduce the latch 27 into the receiving portion of the cantilever.

[0121] exist Figure 5c In the case shown in FIG. 1 , the intermediate piece 15 around the cantilever arm 11 is removed so that the marking felt 7 can be removed from the machine onto the replacement unit 25 or put onto the machine from the replacement unit 26. After the roller cover has been replaced, the intermediate piece 15 can be reintroduced.

[0122] Figure 6a , 6b , 6c and 6d show the steps of replacing the roller sleeve by the fixed replacement unit 25 according to other aspects of the present invention.

[0123] Figure 6a The operator side FS of the machine is shown, wherein a roller collar 7, in particular a marking felt 7, is inserted into the machine. Figure 6a In the case shown, the machine is usually still in operation. The operator-side machine table with the boom 11 still has the corresponding intermediate part 15. During the operation of the machine, the fixed replacement unit 25 can be realized without the use of a crane, for example by installing a plurality of guide rails 28 and / or guide cables 29 as shown in FIG. 6. These guide rails 28 or guide cables 29 can be connected to the machine table, for example the boom 11, by one end and to a support, for example, of a workshop wall, by the other end. The second roller collar 7b is mounted on the fixed replacement unit 25 by the support and shaping of these guide rails 28 or guide cables 29. During the next machine stop, the second roller collar 7b should be moved into the machine in the shortest possible time, while the roller collar 7 is removed.

[0124] In order to replace the roller sleeve more quickly, Figure 6a A sliding layer 30 is provided in the replacement unit 25 in the embodiment. The sliding layer 30 is used to separate the roller shell 7 and the second roller shell 7b from each other when the roller shell is replaced, and to make it easier for the roller shells to be moved one over the other. For this purpose, it is advantageous if the upper side and the lower side of the sliding layer are preferably smoother than the roller shells 7, 7b. The sliding layer 30 can be realized, for example, as a polymer film or a smooth polymer belt.

[0125] The sliding layer 30 is Figure 6a In the embodiment, the sliding layer 30 is realized as a ring, which is sleeved on the replacement unit 25 around the second roller sleeve ring 7b. Alternatively, for example, it can also be provided that the sliding layer 30 is designed in the form of a sliding cover, which only needs to be sleeved outside the second roller sleeve ring 7b. In many cases, this sliding cover is sufficient to achieve the desired effect.

[0126] Figure 6b The next step of changing the roller sleeve is shown. The machine is stationary in this case. The tensioning roller 6 has been moved from the working position 6a to the maintenance position 6b and the lifting element 22 has been decoupled from the marking roller 3 and / or the machine table parts. In addition, the corresponding intermediate piece 15 has been removed. The roller sleeve 7 can now be removed from the machine. The roller sleeve 7, for example the marking felt 7, is here mounted on the fixed replacement unit 25. The roller sleeve 7 is preferably, but not necessarily, mounted on the second roller sleeve 7b. In order to avoid unnecessary effort due to friction between the two roller sleeves 7, 7b during removal, a sliding layer 30 is applied. This makes it easier for the roller sleeve 7 to slide onto the second roller sleeve 7b. Figure 6c The figure shows a state where both the roller cover 7 and the second roller cover 7 b are located on the fixed replacement unit 25 .

[0127] Then you can Figure 6d As shown, the second roll shell 7b is moved into the machine. During this movement, the sliding layer 30 also ensures that the roll shells 7, 7b can be easily moved. It is appropriate to fix the sliding layer 30 preferably during the movement of the roll shell 7 or the second roll shell 7b to prevent the sliding layer from being accidentally removed.

[0128] After the second roller shell 7b has been moved into the machine, the lifting element 22 can be coupled to the marking roller 3 and / or the machine table part, and the tensioning roller 6 can be moved from the maintenance position 6b to the working position 6a and the intermediate piece 15 can be re-inserted. The roller shell replacement is then completed and the machine can be restarted. The fixed replacement unit 25 can then be disassembled and the removed roller shell 7 can be transported away. This work therefore no longer affects the duration of the machine's downtime. In addition, the replacement process shown here can be carried out completely without the use of a workshop crane.

[0129] Depend on Figure 5a-5c and Figure 6a-6d It can be seen that the design of the marking roller or transfer roller, in particular whether they are deflection-compensated rollers, is unimportant for the method shown for changing the roller shell.

[0130] Reference numerals list

[0131] 1 Yankee cylinder / MG cylinder

[0132] 2 transfer rollers

[0133] 3 Marking Rollers

[0134] 4 Transfer Nip

[0135] 5 Marking Nip Zone

[0136] 6 tension rollers

[0137] 6a Working position

[0138] 6b Maintenance position

[0139] 7 Roller sleeve, marking felt, roller sleeve

[0140] 7b Second roller ring

[0141] 8 transport roller sleeve

[0142] 11 Cantilever

[0143] 12 Cantilever

[0144] 13 Cantilever

[0145] 14 Cantilever

[0146] 15Middleware

[0147] 20 Remove the bracket

[0148] 21 Move off track

[0149] 22 Lifting elements

[0150] 22a Decoupled lifting element

[0151] 25 Replacement Unit

[0152] 26 Second replacement unit

[0153] 27 latch

[0154] 28 rails

[0155] 29 Cable guide

[0156] 30 sliding layers

[0157] FS operator side

Claims

1. A machine for producing or processing a fibrous web, comprising a Yankee cylinder (1) for drying and / or smoothing the fibrous web and a transfer roller (2), which can be arranged next to the Yankee cylinder (1) while forming a transfer nip (4), wherein: The machine further comprises a marking roller (3) which can be arranged next to the Yankee cylinder (1) while forming a marking nip (5), wherein the marking nip (5) is arranged downstream of the transfer nip (4) as viewed in the running direction of the fibrous web, and wherein the machine comprises a roller cover (7), in particular a marking felt (7), wherein the roller cover (7) is arranged around the marking roller (3) in the form of a roller collar and is guided through the marking nip (5), characterised in that the marking roller (3) and preferably the transfer roller (2) are designed as deflection compensation rollers.

2. Machine according to one of the preceding claims, characterized in that At least one, in particular all, of the deflection compensation rollers comprise a rotatable casing composed of a fiber composite material, in particular a glass-fiber reinforced plastic casing, which in particular has an outer coating composed of polyurethane.

3. Machine according to one of the preceding claims, characterized in that The machine has a transport roller shell (8) for transporting a fibrous web to a Yankee cylinder (1), wherein the transport roller shell (8) is guided together with the fibrous web through the transfer nip (4).

4. Machine according to one of the preceding claims, characterized in that The machine comprises a removal device in order to move the marking roller (3) laterally out of the machine.

5. The machine according to claim 4, characterized in that The removal device comprises a removal rail (21) and a removal bracket (20) connected to the marking roller (3), wherein the removal bracket (20) can be moved along the removal rail (21) and can be removed from the machine together with the marking roller (3).

6. Machine according to one of the preceding claims, characterized in that At least one lifting element (22) is provided for (3) deflecting the marking roller (3) towards the Yankee cylinder (1) or away from the Yankee cylinder (1), the lifting element being connected to the marking roller (3) and a machine table part of the machine, wherein the lifting element (22) is designed to be decoupled from the marking roller (3) and / or the machine table part.

7. The machine according to claim 6, characterized in that The lifting element (22) comprises a hydraulic cylinder (22) or is formed by a hydraulic cylinder.

8. Machine according to one of the preceding claims, characterized in that The machine comprises a tensioning roller (6), wherein a roller collar (7) is arranged around the marking roller (3) and the tensioning roller (6) and is guided through a marking nip (5), and wherein means are provided in the machine for moving the tensioning roller (6) from a working position (6a) to a maintenance position (6b).

9. A method for replacing a roller cover (7) of a machine for producing or processing a fibrous web, the machine comprising a Yankee cylinder (1) for drying and / or smoothing a fibrous web and a transfer roller (2) which can be arranged next to the Yankee cylinder (1) while forming a transfer nip (4), wherein: The machine further comprises a marking roller (3) which can be arranged next to the Yankee cylinder (1) while forming a marking nip (5), wherein the marking nip (5) is arranged downstream of the transfer nip (4) as viewed in the running direction of the fibrous web, and wherein the machine comprises a roller cover (7), in particular a marking felt (7), and a tensioning roller (6), wherein the roller cover (7) is arranged in the form of a roller collar around the marking roller (3) and the tensioning roller (6) and is guided through the marking nip (5), and wherein The machine is provided with means for moving the tensioning roller (6) from a working position (6a) to a maintenance position (6b), and at least one lifting element (22) is provided for (3) deflecting the marking roller (3) towards or away from the Yankee cylinder (1), the lifting element being connected to the marking roller (3) and a machine part of the machine, wherein the lifting element (22) is designed to be decoupled from the marking roller (3) and / or the machine part, and characterized in that the method comprises the following steps: a. moving the tensioning roller (6) from the working position (6a) to the maintenance position (6b), b. decoupling the lifting element (22) from the marking roller (3) and / or the machine part, c. providing a first replacement unit (25) for accommodating the roller ring (7), d. Transferring the roller collar (7) from the machine to the first changing unit (25).

10. The method according to claim 9, characterized in that The method further comprises the following steps: e. providing a second replacement unit (26), on which a second roller ring is mounted, f. transferring the second roller collar from the second replacement unit (26) into the machine so that the second roller collar (7b) is arranged around the marking roller (3) and the tensioning roller (6), g. coupling the lifting element (22) with the marking roller (3) and / or the machine component, h. Move the tensioning roller (6) from the maintenance position (6a) to the working position (6b).

11. The method according to claim 9, characterized in that Method steps c. and d. are carried out as follows: e. providing a first replacement unit (25) for accommodating the roller collar (7), wherein the second roller collar (7b) is mounted on the first replacement unit (25), f. Transferring the roller ring (7) from the machine to the first changing unit (25), wherein the roller ring is in particular placed on the second roller ring.

12. The method according to claim 11, characterized in that A sliding layer (30) is arranged between the roller ring (7) and the second roller ring (7b), wherein the roughness of the upper side and the lower side is in particular smaller than the roughness of the roller ring (7) and the second roller ring (7b).

13. The method according to claim 11 or 12, characterized in that: The method further comprises the following steps: i. transferring the second roller collar from the first replacement unit (25) into the machine so that the second roller collar (7b) is arranged around the marking roller (3) and the tensioning roller (6), wherein the first roller collar (7) in particular remains on the replacement unit (25), j. coupling the lifting element (22) with the marking roller (3) and / or the machine part, k. Move the tensioning roller (6) from the maintenance position (6a) to the working position (6b).

14. The method according to any one of claims 9 to 13, characterized in that The first replacement unit (25) and / or the second replacement unit (26) are designed as mobile replacement units (25, 26) having a latch (27), and the machine has a receptacle for the latch (27) and is positioned when providing the first replacement unit (25) and / or the second replacement unit (26) so that the latch (27) is introduced into the receptacle.

15. The method according to any one of claims 9 to 13, characterized in that The first replacement unit (25) is designed as a fixed replacement unit (25) having a plurality of guide rails (28) and / or guide cables (29), wherein the guide rails (28) and / or guide cables (29) are fixed to the machine table and, if necessary, to a support.

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