DE202022104495U1 - machine - Google Patents

Abstract

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 applied to the Yankee cylinder (1) to form a transfer nip (4), wherein
the machine further comprises a marking roller (3) which can be placed against the Yankee cylinder (1) to form a marking nip (5), the marking nip (5) being arranged after the transfer nip (4) as viewed in the running direction of the fibrous web,
and wherein the machine has a covering (7), in particular a marking felt (7), the covering (7) being arranged in the form of a covering loop around the marking roller (3) and guided through the marking nip (5), characterized in that the marking roller (3) and preferably also the transfer roller (2) is/are designed as a deflection compensation roller.

Description

The invention relates to a machine for the production or processing of a fibrous web, in particular for the production of machine-finished paper (MG paper).

For the production of special papers that are smooth on one side in combination with a very high specific volume, paper machine concepts with a MG cylinder + hot air hood as the central drying unit are used. Such paper machines are, for example, from the writings DE102017118218 A1 and DE102017118222 A1 known. Such usually large heated MG cylinders are also called Yankee cylinders. Within the scope of this application, these two terms are used synonymously.

Applying a moist paper web to a hot MG cylinder creates a very high gloss and smoothness on the underside of the paper web. This in connection with a high specific volume of the paper, because unlike in a calender, the gloss and/or the smoothness is not generated in a calender nip by high line loads, which compresses the paper.

When using MG papers in the packaging sector (e.g. bakery bags), special line patterns on the paper surface, which have a purely visual function, may be required in addition to the high one-sided gloss. There are a number of different pattern types that have established themselves on the market. These special lines can be created with the help of a press, often in combination with a marking felt at the inlet of the MG cylinder, since the paper web has an ideal moisture content in the range of 40-58% there and the visual contrast can be developed as a result.

So far, these lined papers have only been produced on older, slow-running and narrow MG machines with widths of up to approx. 4m.

It is of course desirable to make the described marking possible with the help of a marking felt for new, high-speed and wide MG systems, or to be able to produce the products described on these systems under economically viable conditions.

Surprisingly, the difficulty is that these wide, fast plants offer a very large production capacity. While a previous plant could be utilized to capacity with such lined qualities, lined qualities generally only make up a certain, small proportion of the total production in modern plants. In addition, there can be a variety of different marking patterns, each of which requires its own marking felt. Thus, a frequent change of variety occurs during production.

The object of the invention is to propose a machine with which special papers can be reliably produced even with large machine widths.

It is also the object of the invention to propose a machine that can still be operated in an economically viable manner even with small production quantities of individual types and frequent changes of type during production.

The present invention also has the task of designing the machine in such a way that a wide fabric - e.g. a marking felt with a width of up to 9 m - must be able to be optionally pressed onto the paper web on the MG cylinder (on/off) and the felt change times must also be as short as possible.

This serves in particular to enable the new paper machines to have a high overall system efficiency.

The objects are solved by a machine according to independent claim 1 . Advantageous embodiments are described in the dependent claims.

With regard to the machine, the object is achieved by a machine for producing or processing a fibrous web, comprising a Yankee cylinder for drying and/or smoothing the fibrous web, and a transfer roller which can be placed on the Yankee cylinder to form a transfer nip. The machine also includes a marking roller which can be placed against the Yankee cylinder to form a marking nip, with the marking nip being arranged after the transfer nip, viewed in the running direction of the fibrous web.

The machine also has a covering, in particular a marking felt, the covering being arranged in the form of a covering loop around the marking roller and guided through the marking nip.

According to the invention, it is provided that the marking roller and preferably also the transfer roller is/are designed as a deflection compensation roller.

Usually the fibrous web is a paper web, for example a MG paper web.

The terms covering and felt or marking felt are used synonymously in the context of this application, since the marking felt is by far the most common application in connection with the marking roller. However, it is possible that instead of a marking felt, a fabric, a foil or another suitable covering can also be used.

Yankee cylinders for use in this invention may be, for example, cast cylinders. However, the use of Yankee cylinders with a steel jacket is also very advantageous.

The Yankee cylinders are usually heated from the inside with hot steam that is under a certain pressure. This leads to a deformation of the Yankee cylinder. The cylinder is inflated as it were. This effect is particularly significant at the driver-side or drive-side edges of the Yankee cylinder. While the shell is strongly deformed outwards, the end caps remain largely unchanged. Therefore, the surface of the Yankee has a strong gradient in this edge area.

It is - for example from the EP 3 974 576 A1 - Known to use a so-called deflection compensation roll in combination with the Yankee cylinder as a transfer roll. In contrast to classic rollers, which are cylindrical or designed with a fixed camber, deflection compensation rollers make it possible to adjust the profile of the marking nip across the width, and thus also the profile of the contact pressure. Deflection compensation rolls are also referred to as deflection compensation rolls. The registration ring sells such rollers under the brand name NipCo rollers.

In this case, the fibrous web is expediently transferred to the Yankee cylinder in the region of such a deflection-compensating roll applied to the Yankee cylinder. In this way, uniform pressure and stable transfer of the web to the Yankee cylinder can be achieved, particularly in the area of the edges.

According to the present invention, what is known as a deflection compensation roller is now also used in particular as a marking roller. Such deflection compensation rolls are also called deflection compensation rolls or NipCo (NipCorrect) rolls.

The wider the Yankee cylinder, the stronger the Yankee surface deformation phenomenon. And the wider the Yankee cylinder, the greater the risk that when using classic rollers as marking rollers, the pressure force of the roller or the covering (especially the marking felt) on the paper web will vary across the width of the fibrous web, resulting in uneven markings Markings of the paper web can come. Compensation through a general increase in the contact pressure is not desirable, since this leads to over-pressing of the web at other points and the specific volume of the web suffers. Using a deflection compensation roller, the marking nip can be controlled in a targeted manner and the marking pattern on the fibrous web can also be set in a targeted manner. Especially with widths of the Yankee cylinder of 6m and more, in particular 7m, 8m or 9m and more, the use of a deflection compensation roller as a marking roller is very advantageous.

The use of a deflection compensation roller as a marking roller also offers advantages because the machine should be optimized for frequent brand changes. With different grades, the machine is operated with different steam pressures in the Yankee cylinder, which leads to significantly different deformations. These can be compensated for by means of the deflection compensation roller, which ensures an even marking nip and an even marking pattern on the fibrous web.

In many cases it will be expedient for the machine to have a transfer clothing for transporting the fibrous web to the Yankee cylinder, with the transfer clothing being guided through the transfer nip together with the fibrous web.

In advantageous embodiments, it can be provided that at least one, in particular all of the deflection compensation rollers, comprise a rotatable jacket made of a fiber composite material, in particular a GRP jacket, which in particular has an outer coating made of polyurethane. GRP glass fiber reinforced plastic is a material made of plastic and glass fibers.

Pressing can be done, for example, by means of a deflection compensation roll with elastic material made of a GRP composite material, such as a NipcoFullFlex roll with convex support sources, or by means of a shoe press roll, such as a NipcoFlex-T roll as in tissue machines, i.e. a shoe roll with a concave pressure shoe QualiFlex jacket.

A deflection compensation roll with an Elast cover can be used - such as the so-called NipcoFullFlex roll - a deflection compensation roll with a composite cover be used, which is significantly more flexible than a steel or cast iron jacket and can therefore follow the contour of the Yankee cylinder better. Such a roll stands out from a shoe roll, among other things, in that no concave shoe is used as the support source, but rather several convex support sources, mostly closely spaced apart over the length of the roll or width of the machine. Such a coat consists of a CFRP coat or GRP coat with an outer coating made of polyurethane. Such a jacket is more flexible than a steel or cast iron jacket, so that it can adapt better to a changing contour of the Yankee cylinder. With such a pressure roller (marking roller and/or transfer roller) arranged on the Yankee cylinder, there is good adaptation to a particular Yankee cylinder deformation, a uniform linear force distribution in the transverse direction and uniform quality properties with regard to thickness, smoothness and gloss.

In preferred embodiments, 2 deflection compensation rolls can thus be arranged on the Yankee cylinder, each in separate, independent clothing loops. The first of the two rollers shall be referred to as the "transfer roller", the second as the "marking roller". A cantilever carrier can be incorporated into each stringing loop. a

The deflection compensation rolls adapt ideally to the respective crowning condition of the Yankee cylinder, which results from different steam pressures in the Yankee cylinder.

The first deflection compensation roll, including a possible associated protective felt loop as transfer clothing, has the task of transferring the paper web to the MG cylinder and fixing it there evenly in the CD direction (i.e. in the cross-machine direction).

The second deflection compensation roller behind it in the direction of travel creates a mark, e.g. a line embossing, on the paper web surface with its own circulating marking felt.

The second nip - called the marking nip - can optionally also be pivoted away / moved back, so that a paper web can be produced without a line marking.

Fast and non-destructive felt change

Due to possible small production quantities of the respective marked, in particular lined paper qualities, the marking felts are usually far from worn out when the felt is changed. It therefore makes neither economic nor ecological sense to cut up and dispose of the old marking felt, as is usually the case, when changing the felt. Rather, it is desirable if this felt can be used again in the next production of the corresponding type. Therefore, this invention also strives for a non-destructive felt change concept.

To solve these problems, the inventors have developed various ideas that are inventive both individually and in combination with one another.

• • einer schwenkenden und aus der Maschine ausfahrbaren Markierwalze als Biegeausgleichswalze
• • einer Cantileverstuhlung welche den Einsatz von Endlosfilzen ermöglicht
• • einem automatisches Ablagesystem für eine Spannwalze
• • einem Filzwechselkonzept inklusive 2-fach Wechselgestell.

In order to be able to produce additional different embossing patterns and to be able to change them quickly, a special changing concept for the marking felt consisting of the following elements was developed:

• • a pivoting marking roller that can be pulled out of the machine as a deflection compensation roller
• • a cantilever seating which enables the use of endless felts
• • an automatic storage system for a tension roller
• • a felt changing concept including a double changing frame.

This makes it possible to pull the marking felt in the machine out of the machine without destroying it (without having to cut it up as usual) in order to be able to use it again in later production. In addition, a new marking felt can be drawn in very quickly, meaning that production can be restarted with a new pattern after a changeover time of 30-90 minutes.

For safety-related reasons, the marking felt cannot be carried out while the MG section is running, which is why the duration of the felt change is of great importance for the system efficiency. Several ideas have been developed for this.

Idea 2.1 Pull-out device for the marking roller including hydraulic cylinder for positioning the roller and locking the pull-out device

In advantageous embodiments, it can be provided that the machine includes an extension device in order to move the marking roller out of the machine laterally.

In particular, it can be provided that the extension device comprises an extension rail and an extension carrier which is connected to the marking roller, the extension carrier along the Extension rail is movable, and can be removed together with the marking roller from the machine.

Furthermore, it can be advantageous that at least one lifting element is provided for pivoting the marking roller onto or away from the Yankee cylinder, which lifting element is connected to the marking roller and a framing part of the machine, with the lifting element being designed such that it can be decoupled from the marking roller and/or the framing part .

In particular, it can be advantageous that the lifting element comprises or consists of a hydraulic cylinder.

The marking roller can, for example, be extended to the area of the machine on the driver's side by means of a permanently integrated device without a crane device. The marking roller can be decoupled from other machine parts, such as hydraulic cylinders, rotary bearings, etc., and can be completely extended out of the machine by means of a pulling device (manually or automatically). will. From there, the crane can pick up the entire roller in one go.

It can be provided that the marking roller is connected or can be connected to an extension carrier. This extension carrier can be guided in an extension rail and removed from the machine together with the marking roller. An alternative “marking roller” that may be required can then be attached to this extension beam, which is also an entry beam, and then reinserted into the exit rail.

Advantageously, a lifting element can be provided for pivoting the marking roller up and down. This lifting element is usually connected to both the marking roller and the framing. This lifting element can be decoupled from the roller or from the framing to change the marking felt and to extend and retract the marking roller. For example, the lifting element can be designed as a hydraulic lifting cylinder and can be decoupled from the marking roller. When the roller is extended - together with the extension beam - the lifting element can remain on the framing in the machine.

Cantilever concept of the framing in this position

The cantilever and machine frame of the Yankee cylinder can be designed in such a way that 2x fabric guides (felt/wire) can be arranged one above the other, e.g. with integrated deflection compensation rolls. Additional cantilever carriers can be introduced for the felt/wire run arranged below (support of the main cantilever carrier).

Idea 2.2 Automatic storage system for the tension roller without the use of a crane

Furthermore, it can be advantageous if the machine comprises a tensioning roller, the clothing loop being arranged around the marking roller and the tensioning roller and guided through the marking nip, and means being provided in the machine to move the tensioning roller from a working position to a maintenance position to move.

The tensioning roller in the clothing loop can be brought into a storage position by means of a rotatable or translatory device. This is done without the help of a crane. This is advantageous because the crane is freely available for other work during this activity. This means that important downtime can be minimized or saved in the overall context of the felt/wire change. This is all the more important since, as a rule, only one indoor crane is provided in a paper machine hall, and the availability or non-availability of this crane has a decisive influence on the duration of the maintenance downtime.

The maintenance position of the tensioning roller is selected in such a way that the covering loop of the marking felt is not under tension when the tensioning roller is in the maintenance position. This freedom from tension is a prerequisite for being able to remove the marking felt from the machine and pull it in undamaged.

change of covering

Furthermore, a method for changing a covering of a machine for producing or processing a fibrous web is proposed. The machine includes a Yankee cylinder for drying and / or smoothing the fibrous web, and a

Transfer roller which can be placed on the Yankee cylinder to form a transfer nip, the machine further comprising a marking roller which can be placed on the Yankee cylinder to form a marking nip, the marking nip being arranged after the transfer nip when viewed in the running direction of the fibrous web.

Furthermore, the machine comprises a covering, in particular a marking felt, and a tensioning roller, the covering being arranged in the form of a covering loop around the marking roller and the tensioning roller, and through the marking nip is guided. In addition, means are provided in the machine to move the stretching roller (6) from a working position to a maintenance position.

In addition, at least one lifting element is provided for pivoting the marking roller against the Yankee cylinder, which is connected to the marking roller and a framing part of the machine, the lifting element being designed so that it can be decoupled from the marking roller and/or the framing part.

The marking roller and/or the transfer roller can be designed as a deflection compensation roller. This is not absolutely necessary for the process of changing the clothing. The method works just as well for machines in which the marking roller and/or the transfer roller are designed as classic rollers, e.g. as cambered rollers, in particular with a negative camber.

1. a. Bewegen der Spannwalze von der Arbeitsposition in die Wartungsposition
2. b. Entkoppeln des Hubelements von der Markierwalze und/oder dem Stuhlungsteil
3. c. Bereitstellen einer ersten Wechseleinheit zur Aufnahme der Bespannungsschlaufe
4. d. Transfer der Bespannungsschlaufe aus der Maschine auf die erste Wechseleinheit

The procedure includes the following steps:

1. a. Moving the tension roller from the working position to the maintenance position
2. b. Decoupling the lifting element from the marking roller and/or the framing part
3. c. Providing a first interchangeable unit for accommodating the clothing loop
4. i.e. Transfer of the clothing loop from the machine to the first exchange unit

• e. Bereitstellen einer zweiten Wechseleinheit, auf der eine zweite Bespannungsschlaufe aufgezogen ist
• f. Transfer der zweiten Bespannungsschlaufe von der zweiten Wechseleinheit in die Maschine, so dass sie zweite Bespannungsschlaufe um die Markierwalze und die Spannwalze herum angeordnet ist.
• g. Koppeln des Hubelements mit der Markierwalze und/oder das Stuhlungsteil
• h. Bewegen der Spannwalze von der Wartungsposition in einer Arbeitsposition.

In preferred embodiments, the method can also include the steps:

• e. Providing a second changing unit on which a second clothing loop is pulled
• f. Transfer of the second clothing loop from the second changing unit into the machine so that the second clothing loop is arranged around the marking roller and the tensioning roller.
• G. Coupling the lifting element with the marking roller and/or the framing part
• H. Moving the idler roll from the maintenance position to a working position.

The felt/wire changing unit is designed to enable fast changing times of the felts/wires. The changing unit can be designed in this way by means of location-defined guide rails (support strips) along the wire loop in the machine.

• c. Bereitstellen einer ersten Wechseleinheit zur Aufnahme der Bespannungsschlaufe, wobei auf die erste Wechseleinheit eine zweite Bespannungsschlaufe aufgezogen ist
• d. Transfer der Bespannungsschlaufe aus der Maschine auf die erste Wechseleinheit, wobei die Bespannungsschlaufe insbesondere auf die zweite Bespannungsschlaufe abgelegt wird.

In an alternative form of the method, it can be provided that method steps c. and d. be executed as follows:

• c. Providing a first replacement unit for receiving the clothing loop, a second clothing loop being pulled onto the first replacement unit
• i.e. Transfer of the clothing loop from the machine to the first changing unit, with the clothing loop being placed in particular on the second clothing loop.

• f. Transfer der zweiten Bespannungsschlaufe von der ersten Wechseleinheit in die Maschine, so dass sie zweite Bespannungsschlaufe um die Markierwalze und die Spannwalze herum angeordnet ist, wobei insbesondere die erste Bespannungsschlaufe auf der Wechseleinheit verbleibt
• g. Koppeln des Hubelements mit der Markierwalze und/oder dem Stuhlungsteil.
• h. Bewegen der Spannwalze von der Wartungsposition in die Arbeitsposition

Here, in advantageous embodiments, it can be provided that the method also has the steps:

• f. Transfer of the second clothing loop from the first exchange unit into the machine, so that the second clothing loop is arranged around the marking roller and the tensioning roller, with the first clothing loop in particular remaining on the exchange unit
• G. Coupling the lifting element with the marking roller and/or the framing part.
• H. Moving the tension roller from the maintenance position to the working position

With this variant of the method, both the clothing can be removed from the machine and the second clothing can be drawn into the machine with a single changing unit. The provision of a second exchange unit and moving these exchange units back and forth is no longer necessary, as a result of which the change of clothing can be further accelerated.

In this embodiment of the method, the clothing is pulled over the second clothing, which is located on the first exchange unit, when it is pulled out of the machine. If one or both fabrics have a rough surface, this can be difficult or forceful.

It can therefore be advantageous if a sliding layer is arranged between the clothing loop and the second clothing loop, with both the upper side and the underside in particular having a lower roughness than the clothing loop and the second clothing loop. This facilitates both the removal of the stringing loop from the machine and the drawing of the second stringing loop into the machine.

The slide layer can be a polymer film or a smooth polymer tape, for example.

Expediently, the slide layer with the second clothing loop can be put on a corresponding changing unit while the machine is still running. Thus, the machine downtime is not increased by the provision of the sliding layer.

Furthermore, it can be advantageous if the first exchange unit and/or the second exchange unit is designed as a mobile exchange unit, which can be moved with an indoor crane, for example. This enables the felt/screen to be quickly extended onto the empty exchange unit docked with the crane. The same applies to inserting the felts/screens using the docked, second exchange unit equipped with a felt/screen and with the second fabric loop.

It can advantageously be provided that such a mobile interchangeable unit has an attachment pin and the machine has a receptacle for the attachment pin, and that when readying the first interchangeable unit and/or the second interchangeable unit is positioned such that the attachment pin is inserted into the receptacle .

The mobile exchange unit can be designed with a mandrel (= slip-on pin) in order to drive it into the structurally adapted cantilever carrier on the front side on the driver's side. This avoids the otherwise protruding mandrel on the cantilever and makes it easier for the operator to access the machine in this area.

It can be advantageous if two mobile exchange units of the same type are available. In this way, the second fabric (felt/wire) to be newly fitted can be fitted onto a first changing device even before the standstill. After the clothing has been pulled onto the first changing unit from the machine and removed from the machine when the machine is at a standstill, the second changing unit can immediately dock onto the cantilever and the new second clothing can be drawn into the machine. In this way, changing the clothing can be further accelerated.

The slip-on spigot can be round, for example, which makes it easier to dock the changing device.

However, the spigot can also be non-round (rectangular, triangular, etc...). This ensures that the changing device is always optimally positioned after docking.

Alternatively, it can be provided that the first exchange unit is designed as a stationary exchange unit. Here, as part of the changing unit, it can be provided, for example, that a number of guide rails and/or guide cables are fastened to the framing and optionally to a counter bearing.

These guide rails or guide ropes can be installed on the operator's side of the machine while the machine is still running.

Likewise, the second clothing can already be pulled up on the stationary changing unit. In addition, it is possible for a sliding layer to be mounted on this stationary exchangeable unit. All this can be prepared while the machine is still running. In addition, all these preparatory measures can be carried out without using an indoor crane. This differs from the use of mobile exchange units, where an indoor crane is usually required to transport the exchange unit due to the weight. The indoor crane can be used for other activities while the stationary changing device is being set up.

It is also possible, for example, that the machine described is part of a larger machine for producing a fibrous web, in particular a paper or cardboard web, with a headbox, a forming unit, a press section, a pre-dryer section, the described MG smoothing Yankee cylinder and a winding , wherein the pre-dryer section is designed in particular for one-sided pre-drying of the fibrous web on its underside, as an MG smoothing Yankee cylinder, for example, an overhead MG smoothing Yankee cylinder is provided with which the underside of the fibrous web is brought into contact.

In particular, in the web travel direction (L) after the pre-dryer section and before the fibrous web runs onto the MG smoothing Yankee cylinder, a remoistening device can be provided for one-sided remoistening of the fibrous web on its underside and accordingly for the development of the moisture gradient in the z-direction of the fibrous web in the direction of its underside be.

However, other possible uses of machines according to aspects of the invention are also possible.

• 1 zeigt eine Maschine gemäß einem Aspekt der Erfindung
• 2 zeigt eine Maschine gemäß einem weiteren Aspekt der Erfindung
• 3 zeigt eine Maschine gemäß einem weiteren Aspekt der Erfindung
• 4 zeigt eine Maschine gemäß einem weiteren Aspekt der Erfindung
• 5a, 5b und 5c zeigen mobile Wechseleinheiten gemäß weiteren Aspekten der Erfindung
• 6a, 6b, 6c und 6d zeigen die Schritte eines Bespannungswechsels mit einer stationären Wechseleinheit gemäß weiteren Aspekten der Erfindung

The invention is explained in more detail below with the aid of schematic figures. The invention is not limited to the embodiments shown here

• 1 Figure 1 shows a machine according to an aspect of the invention
• 2 Figure 12 shows a machine according to a further aspect of the invention
• 3 Figure 12 shows a machine according to a further aspect of the invention
• 4 Figure 12 shows a machine according to a further aspect of the invention
• 5a , 5b and 5c show mobile exchange units according to further aspects of the invention
• 6a , 6b , 6c and 6d show the steps of a clothing change with a stationary changing unit according to further aspects of the invention

1 shows a section of a machine for the production of a special paper web, such as is used for the production of so-called machine-finished paper (MG paper). An essential component of such a machine is a large, mostly steam-heated cylinder 1, which is referred to as a Yankee cylinder or MG cylinder. The paper web is transported—usually with a moisture content in the range between 40% and 58%—from a transfer clothing 8 to the Yankee cylinder 1 and transferred to the Yankee cylinder 1 in a transfer nip 4 . The transfer nip 4 is formed by the Yankee cylinder 1 and a transfer roller 2 which is applied to the Yankee cylinder 1. Particularly in the case of wide machines that are, for example, 6 m wide or more, it is advantageous if the transfer roller 1 is designed as a deflection-compensating roller. In execution according to 1 a marking nip 5 is arranged after the transfer nip 4 in the running direction of the paper web or in the direction of rotation of the Yankee cylinder 1 . This marking nip 5 is formed by the Yankee cylinder 1 and a marking roller 3, which can be placed against the Yankee cylinder 1 to form the marking nip 5.

The machine also has a covering 7 which is usually designed as a marking felt 7 . This marking felt 7 is guided in a clothing loop around the marking roller 3 and a tensioning roller 6 and, if necessary, further guide rollers and thus also runs together with the paper web through the marking nip 5. 1 shows a state in which the tensioning roller 6 is in a working position 6a, as a result of which the clothing 7 is under a suitable tension. A maintenance position 6b is also provided—for example, a suitable storage position. If the tensioning roller is in the maintenance position 6b, the fabric is not under tension so that the fabric can be changed.

The paper web is smoothed on the side facing the Yankee cylinder 1 and also gets a certain shine. To maintain the specific volume of the paper, this smoothing takes place without the usual calenders.

The side of the paper web facing away from the Yankee cylinder 1 receives a marking in the marking nip 7 when using corresponding marking felts 7, for example in the form of a line. It is important here that despite the deformation of the Yankee cylinder 1 due to the application of steam, the marking nip 3 is very uniform over the entire width of the machine, since otherwise the paper will be marked unevenly, which in the worst case leads to increased rejects. Therefore, in the machine according to aspects of the invention, the marking roller 3 is designed as a deflection compensating roller.

In particular, a deflection-compensating roll with a composite casing can be used as the deflection-compensating roll. Such a coat consists of a CFRP coat or GRP coat with an outer coating made of polyurethane. Such a jacket is more flexible than a steel or cast iron jacket, so that it can adapt better to a changing contour of the Yankee cylinder 1. With such a marking roller 3 (and/or transfer roller 2) arranged on the Yankee cylinder 1, there is good adaptation to a respective Yankee cylinder deformation, a uniform linear force distribution in the transverse direction and uniform quality properties with regard to thickness, smoothness and gloss.

In advantageous embodiments, both the marking roller 3 and the transfer roller 2 can be designed as deflection-compensating rollers, and in particular both can also have a composite casing as described above. The NipcoFullFlex rolls from registration ring are ideally suited for this.

2 shows the machine again 1 , but with a focus on the details of the marking roller 7. The machine again comprises two cantilevers 11, 12; one for each clothing loop 7, 8. An extension rail 20, which extends in the transverse direction of the machine, is attached to the cantilever 11 assigned to the marking felt 7 or the marking roller 3. An extension beam 21 is guided in this extension rail 20 . At this Ausfahrträger 21, the marking roller 3 is attached. This makes it easier to change the marking roller 3, since it can be pulled out and removed very easily along the extension rail 20, for example in the direction of the driver's side FS of the machine. Either the same marking roller 3 or an alternative one can then be attached to the extension beam 21 Roller are attached, and reinserted into the machine by means of the extension rail 20.

the 2 also shows lifting element 20, which is used to apply or move the marking roller 3 to the Yankee cylinder 1. This lifting element 20 is designed here as a hydraulic lifting cylinder 20, which is connected both to the marking roller 3 (or its bearing) and to a framing part. In order to be able to fully utilize the advantages of the extension device described above, the lifting element 20 in 2 designed so that it can be decoupled from the marking roller 3. The decoupled lifting element 22a then remains on the framing while the marking roller 3 is removed or replaced. The lifting element can thus be used both for positioning the rollers and for locking the extension device.

3 shows again a machine of in 1 and 2 shown Art. Here, a variant is shown in which the tension roller 6 can be moved from the working position 6a to the maintenance position 6b without the use of external aids such as an indoor crane. This can be done via a translational movement or a rotary movement, which can take place, for example, along suitable rail elements. Since the use of the indoor crane as a bottleneck resource is again avoided here, this feature contributes noticeably to an accelerated change of the clothing 7 .

4 shows a machine whose framing has at least four cantilevers 11, 12, 13, 14. So-called intermediate pieces 15 are provided between the cantilevers 11, 12 or the cantilevers 11, 12 and other framing parts. If, for example, the marking felt 7 is to be changed, the spacers 15 adjacent to the cantilever 11 can be removed and the marking felt can be inserted or removed through the resulting openings.

the 5a , 5b and 5c go into more detail on a method according to a further aspect of the invention and explain the advantageous use of mobile exchange units 25, 26.

5a shows the side view of an interchangeable unit 25 which is suspended from a holding element on an indoor crane. A support element extends centrally, at the front end of which a push-on pin 28 is provided here. The changing unit has guide rails 28 at least above and to the side of the support element. The clothing is placed on these guide rails 28 when the clothing is changed.

5b shows a front view of such a change unit 25, 26. In this case, a marking felt 7 has already been pulled onto the change unit 25, 26 and lies on the guide rails 28. This can be, for example, a second changing unit 26 onto which an alternative marking felt 7 is mounted, which is then to be drawn into the machine.

As in 5c shown, the spigot 27 can be inserted into a corresponding receptacle on the FS end face of the cantilever 11 on the driver's side. The spigot 27 is in the examples 5a - 5c designed as a round, cylindrical or slightly conical slip-on pin 27 . This facilitates the insertion of the spigot 27 into the receptacle of the cantilever.

At the in 5c In the situation shown, the intermediate pieces 15 around the cantilever 11 have been removed, so that the marking felt 7 can be pulled out of the machine onto the changing unit 25, or from the changing unit 26 onto the machine. After the changing of the covering has been completed, the intermediate pieces 15 can be reinserted.

6a , 6b , 6c and 6d show the steps of a clothing change with a stationary changing unit 25 according to further aspects of the invention.

6a shows the operator's side FS of a machine, with a fabric loop 7, in particular a marking felt 7, being attached to the machine. The machine is in the in 6a situation shown is usually still in operation. The framing of the driver's side with the cantilever 11 still has the corresponding intermediate pieces 15. A stationary changing unit 25 can be erected during operation of the machine without using a crane, for example by 6a a number of guide rails 28 and/or guide ropes 29 can be installed. These guide rails 28 or guide cables 29 can be attached at one end to the frame, for example to the cantilever 11, and at the other end to an abutment such as a hall wall. Supported and shaped by these guide rails 28 or guide cables 29 , a second clothing loop 7b is drawn onto the stationary changing unit 25 . This second clothing loop 7b should be drawn into the machine in the shortest possible time during the next standstill of the machine, while the clothing loop 7 is being removed.

In order to be able to change the stringing even faster, the exchange unit is 25 in 6a a sliding layer 30 is provided. The slide layer 30 serves the fabric 7 and to separate the second covering 7b from one another when changing the covering, and to allow the coverings to be moved more easily over one another. For this it is advantageous if the sliding layer is smoother on its upper side and on its underside than the coverings 7, 7b. The sliding layer 30 can be realized, for example, as a polymer film or as a smooth polymer band.

The sliding layer 30 is in 6a implemented as a loop that is drawn around the second clothing loop 7b on the changing unit 25. Alternatively, provision can also be made, for example, for the sliding layer 30 to be designed in the manner of a sliding cover, which is merely laid over the second clothing loop 7b from above. In many cases, such a sliding cover is sufficient to achieve the desired effect.

In 6b you can now see the next step in changing the covering. In this situation stands. the machine quiet. The tension roller 6 has already been moved from the working position 6a to the maintenance position 6b, and the lifting element 22 is decoupled from the marking roller 3 and/or the framing part. Furthermore, the corresponding intermediate pieces 15 have been removed. The clothing loop 7 can now be pulled out of the machine. The covering 7 , for example a marking felt 7 , is pulled onto the stationary changing unit 25 . Expediently—but not necessarily—the covering loop 7 is pulled over the provided second covering 7b. In order to avoid an unnecessary expenditure of force when pulling out due to the friction of the two coverings 7, 7b on one another, the sliding layer 30 is retracted. Thus, the skin 7 can easily slide over the branched skin 7b. 6c shows a state in which both the clothing 7 and the second clothing 7b are located on the stationary changing unit 25. Subsequently, as in 6d shown, the second clothing 7b are drawn into the machine. The sliding layer 30 also ensures easy movement of the coverings 7, 7b during this retraction. It will be expedient to fix the sliding layer 30 during the movement of such a covering 7 or a second covering 7b in order to prevent this sliding layer from being inadvertently moved away. Once the second covering 7b has been drawn into the machine, the lifting element 22 can be coupled to the marking roller 3 and/or the framing part and the stretching roller 6 can be moved from the maintenance position 6b to the working position 6a, and the intermediate pieces 15 can be reinserted. The clothing change is then complete and the machine can be started up again. The dismantling of the stationary changing unit 25 and the removal of the removed covering 7 can then take place. This work then no longer has any influence on the duration of the machine downtime. Furthermore, the changing process shown here can be implemented entirely without using an indoor crane.

How from the 5a - 5c and 6a - 6d, it is irrelevant for the methods for changing the clothing shown how the marking roller or transfer is designed, in particular whether it is a deflection-compensating roller or not

Reference List

1

Yankee cylinder/ MG cylinder

2

transfer roller

3

marking roller

4

transfer nip

5

marking nip

6

idler roller

6a

working position

6b

maintenance position

7

Cover, marking felt, cover loop

7b

second stringing loop

8th

transfer covering

11

cantilever

12

cantilever

13

cantilever

14

cantilever

15

spacer

20

extension beam

21

exit rail

22

lifting element

22 a

decoupled lifting element

25

exchange unit

26

second exchange unit

27

spigot

28

guide rail

29

guide rope

30

sliding position

FS

guide page

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102017118218 A1 [0002]
• DE 102017118222 A1 [0002]
• EP 3974576 A1 [0020]

Claims (8)

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 placed on the Yankee cylinder (1) to form a transfer nip (4), the machine further comprises a marking roller (3) which can be placed against the Yankee cylinder (1) to form a marking nip (5), the marking nip (5) being arranged after the transfer nip (4) as viewed in the running direction of the fibrous web, and the machine having a has a covering (7), in particular a marking felt (7), the covering (7) being arranged in the form of a covering loop around the marking roller (3) and guided through the marking nip (5), characterized in that the marking roller (3) and preferably also the transfer roller (2) is/are designed as a deflection compensation roller. 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 jacket made of a fiber composite material, in particular a GRP jacket, which in particular has an outer coating made of polyurethane. Machine according to one of the preceding claims, characterized in that the machine has a transfer clothing (8) for transporting the fibrous web to the Yankee cylinder (1), the transfer clothing (8) being guided through the transfer nip (4) together with the fibrous web. Machine according to one of the preceding claims, characterized in that the machine comprises an extension device in order to move the marking roller (3) laterally out of the machine. machine after claim 4 , characterized in that the extension device comprises an extension rail (21) and an extension carrier (20) which is connected to the marking roller (3), the extension carrier (20) being movable along the extension rail (21) and together with the Marking roller (3) can be removed from the machine. Machine according to one of the preceding claims, characterized in that at least one lifting element (22) is provided for pivoting the marking roller (3) onto or away from the Yankee cylinder (1), which is connected to the marking roller (3) and a framing part of the machine is, wherein the lifting element (22) of the marking roller (3) and / or the framing part is designed to be decoupled. machine after claim 6 , characterized in that the lifting element (22) comprises or consists of a hydraulic cylinder (22). Machine according to one of the preceding claims, characterized in that the machine comprises a tensioning roller (6), the clothing loop (7) being arranged around the marking roller (3) and the tensioning roller (6) and guided through the marking nip (5). , and wherein means are provided in the machine to move the stretching roller (6) from a working position (6a) to a maintenance position (6b).

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