EP1281806A2 - Press arrangement - Google Patents

Abstract

A web of paper or carton passes through a paper manufacturing assembly (10) with two elongated slit presses (12,14), each forming an elongated slit in the direction of web travel (L). The assembly has especially an additional press slit (16). The additional press slit is formed by a pre-press (18) located prior to the two long-slit presses (14,16). The pre-press is double felt press. As seen in the direction of web motion the pre-press and long slit press (12) have a joint felt (26,28). The pre-press and first long slit press (12) share a common upper felt (26) and a common lower felt (28).

Description

The invention relates to a press arrangement for treating a material web, especially paper or cardboard web, with two long nip presses, which each form an extended press nip in the direction of web travel

Characteristic of the so-called "Tandem NipcoFlex" press arrangements are the two double felted long gap presses. This is done the leadership of the fibrous web after the first press nip because of relatively high humidity to ensure safe web guidance between the two press felts of the first press nip.

However, such a press concept is now particularly useful for SC papers Problems especially with regard to printability. The cause probably lies in the large drainage of the first press and an accompanying washout of fillers.

As already mentioned, such a "tandem NipcoFlex" press arrangement by default, two press nips or nips on, as a rule both nips are double felted. In the second nip, for example also used a more or less smooth press belt in the lower position become.

Both nips can be made, for example, by shoe presses in the direction of web travel extended press zone can be realized. But it is, for example also possible to form the first nip by a roller press.

The "Tandem NipcoFlex" press assemblies are for high speed, high dryness and stable web guidance, i.e. a high runability, designed.

As a result of the high drainage capacity of this press concept extracted large amounts of water from the paper in the two nips. The far The largest amount of water is naturally extracted from the paper in the first nip.

As already mentioned, local leaching of Fine or filler on the paper surface. So-called "Crater" on the paper surface. Accordingly, a higher one must be in the calender Pressure is generated to achieve the required smoothness. Otherwise For example, in the gravure printing process, missing areas may remain, that do not accept printing ink, which makes the printout in particular is disturbed in the semitones and quarters.

An improvement can be made by reducing the amount of drainage in the first nip can be achieved. However, this can now adversely affect the Impact web guide after the first press. For example, it can In addition, the web edges change after the upper felt is separated Detach from the bottom felt on the suction felt guide roller and straighten up. moreover the amount of drainage increases in the second nip, which results in higher porosity of the paper, especially if in this second nip a press belt is used in the lower position.

It is advantageous for the surface of the paper if in the first press nip or nip the dehydration through an adapted shoe shape and reduced Contact pressure is reduced.

The dry content usually drops after a respective change of clothing after the press section, and the moisture cross profiles worse. These effects still occur when the first press is unloaded to a greater extent, resulting in loss of quality and problems the runability can lead.

The aim of the invention is to provide an improved press arrangement at the beginning to create the type mentioned, in which the aforementioned problems under Maintaining the benefits of a "Tandem NipcoFlex" press arrangement are eliminated.

This object is achieved according to the invention in that another Press nip is provided.

Due to this training, the drainage can be better distributed to the individual nips. The gradual drainage across the entire press section results in a stronger compaction of the surface and thus better binding of the fillers. A more sensitive distribution of the drainage over the press section is possible without having to do without the other advantages of a standard "Tandem NipcoFlex" press arrangement.
The further press nip can be formed, for example, by a pre-press upstream of the two long-nip presses or a post-press downstream of these.

If the further press nip is formed by a pre-press, this can, for example be double felted.

The pre-press and the first long-nip press viewed in the direction of web travel are preferably provided with at least one common felt.

In a preferred practical embodiment of the invention Press arrangement are the pre-press and the first long-nip press both with a common top felt as well as with a common one Provided under felt.

The pre-press can, for example, have at least one suction press roll in the upper one Position and at least one massive press roll or at least one deflection controlled roll. You can also by a roller press or also be formed by a shoe press.

In certain cases it is also advantageous if the direction of travel considers the first press to be a roller press. For example also a roller press instead of the first extended nip press be provided.

The second extended nip press viewed in the direction of web travel can, for example double felted or with a felt and a transfer ribbon be provided. A transfer ribbon brings due to its smooth surface improved guidance of the fibrous web and a reduction in Rewetting with itself.

In an expedient embodiment, the second extended nip press provided with an upper felt and a lower transfer belt.

To improve the drainage performance of the pre-press and to reduce it the rewetting of the material or fiber web from Prepress and the first extended nip press can, for example, be made of press felt also with a common upper felt and with separate ones Bottom felts should be provided.

As already mentioned, the further press nip can in principle also be a post-press downstream of the two long-gap presses is formed his. Such a postpress can be the first drying cylinder of the following one Replace dryer section, what with a subsequent installation is essential.

The postpress is conveniently felted. An easy one Web guidance also results when the postpress with an upper felt is performed.

For example, the post-press can have an upper, in particular be dense press felt. In this case the post press preferably has a lower roller with an at least substantially closed or smooth surface. It can be used in particular as the lower roller a ceramic roller or the like may be provided. As the top The post-press roller is, for example, a deflection-controlled one Roller conceivable. The postpress can, for example, also with a upper shoe press unit, preferably a shoe press roll his.

In another expedient embodiment of the invention Press arrangement is the simply felted post press with a lower one Press felt provided. In this case, the postpress can accordingly upper roller with an at least substantially closed or have a smooth surface. A ceramic roller can in particular be used as the upper roller or the like may be provided. The lower roller of the post press can be, for example, a deflection-controlled roller. alternative the postpress can, for example, also with a lower one Shoe press unit, preferably shoe press roll, may be provided.

The material web receives a particularly symmetrical treatment when the second press with an at least substantially smooth roller or a smooth press belt in the lower position and the post press with one also smooth roller is designed as a top roller.

In an expedient practical embodiment of the invention Press arrangement is the second viewed in the direction of web travel Provide press with a smooth bottom roller and simply felted and also the finishing press is simply felted and carried out with a smooth top roller.

As already mentioned, each can instead of a respective smooth press roll an at least substantially smooth press belt is also provided his.

In certain cases it is also advantageous if the take-off suction roll, in the area of which the material web from a wire belt of the wire section is removed, is simultaneously provided as a suction press roll.

In a further advantageous embodiment, the is in the web running direction considers the second extended press nip and the postpress led a common press belt.

In certain cases it is useful if extended by the second Press nip and a common felt passed through the postpress is.

The post-press can in particular also be used as a smoothing press with a smooth one Bottom roller may be provided.

Fig. 1

eine schematische Darstellung einer beispielhaften Ausführungsform einer zwei Langspaltpressen sowie eine Vorpresse umfassenden Pressenanordnung, bei der die Vorpresse und die erste Langspaltpresse mit gemeinsamen Preßfilzen versehen sind und die zweite Langspaltpresse doppelt befilzt ist,

Fig. 2

eine schematische Darstellung einer weiteren zwei Langspaltpressen sowie eine Vorpresse umfassenden Ausführungsform einer Pressenanordnung, bei der die zweite Langspaltpresse jedoch mit einem Filz und einem Transferband versehen ist,

Fig. 3

eine schematische Darstellung einer weiteren zwei Langspaltpressen sowie eine Vorpresse umfassenden Ausführungsform einer Pressenanordnung, bei der die Vorpresse und die erste Langspaltpresse mit einem gemeinsamen Oberfilz und mit getrennten Unterfilzen versehen sind,

Fig. 4

eine schematische Darstellung einer beispielhaften Ausführungsform einer Pressenanordnung mit einer den beiden Langspaltpressen nachgeschalteten Nachpresse, die mit einem oberen Preßfilz und einer glatten unteren Walze versehen ist,

Fig. 5

eine schematische Darstellung einer weiteren Ausführungsform einer Pressenanordnung mit einer den beiden Langspaltpressen nachgeschalteten Nachpresse, wobei die zweite Langspaltpresse mit glatter Unterwalze und die Nachpresse mit Unterfilz und einer glatten Oberwalze versehen ist,

Fig. 6

eine schematische Darstellung einer weiteren Ausführungsform einer Pressenanordnung mit einer den beiden Langspaltpressen vorgeschalteten Vorpresse, wobei die Abnahmesaugwalze, durch die die Materialbahn von einem Siebband der Siebpartie abgenommen wird, gleichzeitig als Saugpreßwalze vorgesehen ist,

Fig. 7

eine schematische Darstellung einer weiteren Ausführungsform einer Pressenanordnung mit einer den beiden Langspaltpressen nachgeschalteten Nachpresse, wobei durch den zweiten verlängerten Preßspalt und die Nachpresse ein gemeinsames Preßband geführt ist,

Fig. 8

eine schematische Darstellung einer weiteren Ausführungsform einer Pressenanordnung mit einer den beiden Langspaltpressen nachgeschalteten Nachpresse, wobei durch den zweiten verlängerten Preßspalt und die Nachpresse ein gemeinsamer Filz geführt ist, und

Fig. 9

eine schematische Darstellung einer weiteren Ausführunsform einer Pressenanordnung mit einer den beiden Langspaltpressen nachgeschalteten Nachpresse, wobei die Nachpresse als Glättpresse mit einer glatten Unterwalze, z.B. aus Keramik oder dergleichen, ausgeführt ist.

The invention is explained below using exemplary embodiments with reference to the drawing; in this show:

Fig. 1

2 shows a schematic representation of an exemplary embodiment of a two long nip presses and a press arrangement comprising a pre-press, in which the pre-press and the first long nip press are provided with common press felts and the second long nip press is felted twice,

Fig. 2

1 shows a schematic representation of a further two long nip presses and an embodiment of a press arrangement comprising a pre-press, in which the second long nip press is provided with a felt and a transfer belt

Fig. 3

1 shows a schematic representation of a further two long nip presses and an embodiment of a press arrangement comprising a pre-press, in which the pre-press and the first long nip press are provided with a common top felt and with separate bottom felts,

Fig. 4

1 shows a schematic illustration of an exemplary embodiment of a press arrangement with a secondary press downstream of the two long-nip presses, which is provided with an upper press felt and a smooth lower roller,

Fig. 5

1 shows a schematic representation of a further embodiment of a press arrangement with a secondary press downstream of the two long gap presses, the second long gap press being provided with a smooth bottom roll and the post press being provided with bottom felt and a smooth top roll,

Fig. 6

2 shows a schematic representation of a further embodiment of a press arrangement with a pre-press connected upstream of the two long-nip presses, the take-off suction roll, through which the material web is removed from a wire belt of the wire section, being provided at the same time as a suction press roll,

Fig. 7

2 shows a schematic representation of a further embodiment of a press arrangement with a secondary press downstream of the two long-gap presses, a common press belt being guided through the second extended press nip and the secondary press,

Fig. 8

a schematic representation of a further embodiment of a press arrangement with a postpress downstream of the two long nip presses, a common felt being guided through the second extended press nip and the postpress, and

Fig. 9

is a schematic representation of a further embodiment of a press arrangement with a post-press downstream of the two long-nip presses, the post-press being designed as a smoothing press with a smooth bottom roll, for example made of ceramic or the like.

Figures 1 to 9 each show a press assembly 10 for treatment a web of material, preferably fibrous web, in which it can in particular be a paper or cardboard web.

The press assemblies 10 each comprise two long-nip presses 12, 14, which are preceded by a pre-press 18 (see FIGS. 1 to 3 and 6) or a post-press 20 (see FIGS. 4, 5 and 7 to 9) to form a further press nip 16 ) is connected downstream. The two long-nip presses 12, 14 each form a press nip 22 or 24 which is elongated in the web running direction L.
In the embodiment shown in FIG. 1 with a double-felted pre-press 18 connected upstream of the two long-nip presses 12, 14, the pre-press 18 and the first long-nip press 12 viewed in the direction of web travel L are provided with both a common upper felt 26 and with a common lower felt 28.

In the present embodiment, the pre-press is the upper roller 18 a suction press roll 30 is provided. The lower roller 32 can for example by an approximately cylindrical or massive press roll or a deflection-controlled roller can be formed. Instead, can but also a lower shoe press unit, preferably one Shoe press roll can be provided.

In the present case, the second long-nip press viewed in the web running direction L is 14 double felted.

As can be seen from FIG. 1, this takes over a pickup suction roller 34 guided top felt 26 the fibrous web from a wire belt 36 of the wire section.

The together with the upper felt 26 and the lower felt 28 from the extended Press nip 22 of the first extended nip press 12 fiber web is preferably designed as a suction roll Deflection roller 38 separated from the upper felt 26 and together with the lower felt 28 guided around the deflection roller 38, in the area of which it is then by a through the extended press nip 24 of the second long nip press 14 guided Oberfilz 40 is taken over. In the present case, the fibrous web in an area between the bottom felt 28 of the pre-press 18 and the first long nip press 12 associated deflection roller 38 and a further deflecting roller 42 associated with this bottom felt 28 the upper felt 40 passed through the second extended nip press 14. The upper felt 40 passed through the second long nip press 14 is in the Area of the takeover point 44 around a preferably again as a suction roller trained deflection roller 46 out.

Together with the upper felt 40 and the lower felt 48, the fibrous web then from the extended press nip 24 of the second long nip press 14 led out. The fibrous web is then together with the bottom felt 48 around a deflection roller preferably provided as a suction roller 50 out in the area of the upper felt 40 from the fibrous web and the bottom felt 48 is separated.

Subsequently, the fibrous web is in the area of a suction roll trained deflecting roller 52 taken over by a dryer wire 54 and the first dryer cylinder 56 of the dryer section.

Figure 2 shows an embodiment of a comparable to that of Figure 1 Press arrangement 10, in which the second extended nip press 14, however only one felt, in the present case the upper felt 40, and a transfer belt 58 is provided, which is provided in the lower case in the following case is. The transfer belt 58 has a smooth surface improved guidance of the fibrous web and a reduction in rewetting with himself.

Otherwise, this press arrangement can be the same again, for example They have the same structure as that of FIG. 1 are assigned the same reference numerals.

FIG. 3 shows another one comparable to that of FIGS. 1 and 2 Embodiment of a press arrangement 10 in which the pre-press 18 and the first extended nip press 12, however, only with a common felt, here the top felt 26, and provided with separate bottom felts 60, 62 are. Such a design brings improved drainage performance the pre-press 18 with it and reduces the rewetting of the Fibrous web from press felt, i.e. here the Oberfilz 26, from.

Otherwise, this embodiment can have the same structure, for example have like those of Figures 1 and 2. Corresponding parts are assigned the same reference numerals.

Figure 4 shows a schematic representation of an exemplary embodiment a press assembly 10 with one of the two long nip presses 12, 14 assigned secondary press 20. This secondary press 20 can replace the first drying cylinder of the following dryer section, what with regard to retrofitting is essential.

In the present embodiment, the post-press 20 is simple felted. In the present case it is with an upper dense press felt 64 Mistake.

In addition, the post-press 20 has a lower roller 66 with at least one essentially closed or smooth surface. It can for example, a ceramic roller or the like may be provided. Optionally, the lower roller 66 of the post-press 20 can also be from the inside be heated.

A deflection-controlled, for example, can be used as the upper roller 68 of the secondary press 20 Roll be provided. The postpress 20 can, however for example also with an upper shoe press unit, preferably one upper shoe press roll.

Optionally, the upper shoe press roll can also be used individually Pressure zones can be divided so that influence also with the postpress can be taken on the moisture cross profile.

In special cases, in order to increase the effect of the postpress, it may also be necessary to reduce the amount of drainage in the 1st and 2nd nip becomes.

As can be seen from Figure 4, the fibrous web is through a dryer wire 54 taken from the smooth roller 66 and the dryer section fed.

Otherwise, this embodiment can, for example, at least essentially again the same structure as the explanations of the figures Own 1 to 3. Corresponding parts are the same reference numerals assigned.

The embodiment according to FIG. 5 differs from that of the figure 4 essentially only in that the second shoe press nip 14 with is provided with a smooth bottom roller and the postpress 20 an upper one Roller 70 with an at least substantially closed or smooth Has surface and the dense press felt 72 is provided in the lower position is.

A ceramic roller or the like can be used as the upper roller 70, for example be provided.

As the lower roller 74 of this postpress 20, for example, one deflection-controlled roller can be provided. The postpress 20 can for example, but also with a lower shoe press unit, preferably a lower shoe press roll.

In particular, there is also a symmetrical treatment of the fibrous web possible.

FIG. 6 shows a further embodiment in a schematic representation a press arrangement 10 with one of the two long gap presses 12, 14 upstream pre-press 18. In the present case, the pickup or Removal suction roll 34, in the area of which the web of material from the belt 36 of the wire section is removed, at the same time provided as a suction press roll. This can now form the pre-press 18 with the counter roll 80.

Otherwise, this press arrangement can, for example, at least in the essentially the same structure as that previously described Have press arrangements. As indicated in the lower part of FIG. 6, can instead of the bottom felt 48, for example, again Transfer belt 58 may be provided.

The pre-press 18 can also be equipped with a separate bottom felt his.

Figure 7 shows a schematic representation of an embodiment of a Press assembly 10, in which the second extended nip 24 and the post-press 20 a common press belt 76 is guided. In In this case, the post-press 20 acts as a smoothing press, since it has both sides of the paper smoothes at the same time.

FIG. 8 shows a further embodiment in a schematic representation a press arrangement 10 with one of the two long gap presses 12, 14 downstream post press 20. In this case, by the second extended nip 24 and the postpress 20 a common felt 78th guided.

Otherwise, this press arrangement 10 can in particular at least essentially the same structure as that previously described Have orders.

FIG. 9 shows a further embodiment in a schematic representation a press arrangement 10 with one of the two long gap presses 12, 14 downstream post press 20. In the present case, the post press 20 provided as a smoothing press with a smooth lower roller 82. The smooth bottom Roller 82 can be made of ceramic or the like, for example.

This press arrangement 10 can also be used again, for example be carried out as in connection with the other embodiments has been described. Corresponding parts are also assigned the same reference numerals.

Contrary to the press arrangements described so far, the Embodiment according to Figure 9 after the first nip 12 with the paper web the upper felt and then taken over by the lower felt of the 2nd press 14. Through the second extended press nip and the post press a common press belt is guided. In this case the post press equipped with a smooth bottom roller, which significantly removes rejects facilitated.

LIST OF REFERENCE NUMBERS

10

Press arrangement

12

first long nip press

14

second long nip press

16

further press nip

18

pre-press

20

Nachpresse

22

first extended press nip

24

second extended press nip

26

overfelt

28

bottom felt

30

suction press roll

32

lower roller

34

Pickup suction roll

36

screen belt

38

deflecting

40

overfelt

42

deflecting

44

over location

46

deflecting

48

bottom felt

50

deflecting

52

deflecting

54

dryer

56

drying cylinders

58

transfer tape

60

bottom felt

62

bottom felt

64

press felt

66

lower roller

68

top roller

70

top roller

72

press felt

74

lower roller

76

press belt

78

felt

80

backing roll

82

lower roller

L

Web direction

Claims (39)

Press arrangement (10) for treating a material web, in particular paper or cardboard web, with two long-nip presses (12, 14), each of which forms a press nip elongated in the web running direction (L),
characterized in that a further press nip (16) is provided. Press arrangement according to claim 1,
characterized in that the further press nip (16) is formed by a preliminary press (18) upstream of the two long nip presses (12, 14). Press arrangement according to claim 1 or 2,
characterized in that the pre-press (18) is double felted. Press arrangement according to one of the preceding claims,
characterized in that the pre-press (18) and the first extended-nip press (12) viewed in the web running direction (L) are provided with at least one common felt (26, 28). Press arrangement according to claim 4,
characterized in that the pre-press (18) and the first extended-nip press (12) are provided both with a common upper felt (26) and with a common lower felt (28). Press arrangement according to one of the preceding claims,
characterized in that the pre-press (18) comprises at least one suction press roll (30). Press arrangement according to one of the preceding claims,
characterized in that the pre-press (18) comprises at least one cylindrical or solid press roll. Press arrangement according to one of the preceding claims,
characterized in that the pre-press (18) comprises at least one deflection-controlled roller. Press arrangement according to one of the preceding claims,
characterized in that the pre-press (18) is formed by a roller press. Press arrangement according to one of claims 1 to 9,
characterized in that the pre-press (18) is formed by a shoe press. Press arrangement according to one of the preceding claims,
characterized in that the first press viewed in the web running direction (L) is designed as a roller press. Press arrangement according to one of the preceding claims,
characterized in that the second extended-nip press (14) viewed in the web running direction (L) is double felted. Press arrangement according to one of claims 1 to 11,
characterized in that the second extended nip press (14) viewed in the web running direction (L) is provided with a felt (40) and a transfer belt (58). Press arrangement according to one of claim 13,
characterized in that the second extended nip press (14) is provided with an upper felt (40) and a lower transfer belt (58). Press arrangement according to one of the preceding claims,
characterized in that the pre-press (18) and the first extended-nip press (12) are provided with a common top felt (26) and with separate bottom felts (60, 62). Press arrangement according to one of the preceding claims,
characterized in that the further press nip (16) is formed by a secondary press (64) connected downstream of the two long nip presses (12, 14). Press arrangement according to claim 16,
characterized in that the post-press (20) is provided instead of the first drying cylinder of a subsequent dryer section. Press arrangement according to claim 16 or 17,
characterized in that the post-press (20) is simply felted. Press arrangement according to claim 18,
characterized in that the post-press (20) is provided with an upper press felt (64). Press arrangement according to claim 19,
characterized in that the post-press (20) has a lower roller (66) with an at least substantially closed or smooth surface. Press arrangement according to claim 20
characterized in that the lower roller (66) is heated. Press arrangement according to claim 20 or 21
characterized in that a ceramic roller is provided as the lower roller. Press arrangement according to one of the preceding claims,
characterized in that a deflection-controlled roller is provided as the upper roller (68) of the secondary press. Press arrangement according to one of claims 1 to 22,
characterized in that the post-press (20) is provided with an upper shoe press unit. Press arrangement according to claim 24,
characterized in that the upper shoe press unit is formed by a shoe press roll. Press arrangement according to claim 18,
characterized in that the secondary press (20) is provided with a lower press felt (72). Press arrangement according to claim 26,
characterized in that the post-press (20) has an upper roller (70) with an at least substantially closed or smooth surface. Press arrangement according to claim 27,
characterized in that a ceramic roller is provided as the upper roller (70). Press arrangement according to one of claims 26 to 28,
characterized in that a deflection-controlled roller is provided as the lower roller (74) of the secondary press (20). Press arrangement according to one of claims 26 to 29,
characterized in that the post-press (20) is provided with a lower shoe press unit. Press arrangement according to claim 30,
characterized in that the lower shoe press unit is formed by a shoe press roll. Press arrangement according to one of the preceding claims,
characterized in that the second press, viewed in the direction of web travel (L), is provided with a smooth lower roller and is simply felted, and that the secondary press (20) is also simply felted and designed with a smooth upper roller. Press arrangement according to one of the preceding claims,
characterized in that an at least substantially smooth press belt is provided instead of a respective smooth press roll. Press arrangement according to one of the preceding claims,
characterized in that the material web in the area of a take-off suction roll (34) is removed from a wire belt (36) of the wire section and the take-off suction roll (34) is simultaneously provided as a suction press roll. Press arrangement according to claim 34,
characterized in that a common bottom and top felt is passed through the pre-press (18) and the first extended-gap press (12). Press arrangement according to one of the preceding claims,
characterized in that a common press belt (76) is guided through the second elongated press nip (24) viewed in the web running direction (L) and the secondary press (20). Press arrangement according to one of the preceding claims,
characterized in that a common felt (78) is guided through the second elongated press nip (24) and through the secondary press (20). Press arrangement according to one of the preceding claims,
characterized in that the post-press (20) is provided as a smoothing press with a smooth bottom roller. Press arrangement according to one of the preceding claims,
characterized in that the pre-press has a separate bottom felt.

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