DE102006049025A1 - Apparatus and method for producing a fibrous web - Google Patents

Abstract

The invention relates to a device for producing a fibrous web (115), in particular a paper web, with a headbox (1; 102) and further components such as a former (2; 103), a press section (3; 116), a drying section (125,134), Coating device (129) and / or calender (137), wherein to improve the properties of the fibrous web, the design and / or operation of the headbox (1; 102) alone or in combination with the design and / or operation of at least one further component so is chosen that results in a desired profile of the layer orientation in the z-direction with respect to a curl influencing the fibrous web (115). Furthermore, the invention relates to a corresponding method for producing a fibrous web (115).

Description

The The present invention relates to an apparatus for manufacturing a fibrous web, in particular paper web, with a headbox and other components, such as former, press section, dryer section, Coater and / or calender.

Of Furthermore, the present invention relates to a process for the preparation a fibrous web, in particular a paper web, in which a pulp suspension introduced by means of a headbox in a former and then by means of another Components such as press section, dryer section, coating device and / or calender is further treated.

at the production of a fibrous web, in particular a wood-free Copy paper, it is particularly important that the finished fibrous web in terms of the performance characteristics in the later copying process low or no curl, curvature tendency, Curl and the like. The curl will be for example caused by a Umklimatisierung the fibrous web. By the effect of heat During the copying process, the moisture content of the fibrous web and thus also reduced by the fibers. The fibers shrink and produce Tensions in the fibrous web, which in an asymmetric heating of the fibrous web lead to curl. So far, this tendency to curl has been tried in the manufacturing process of the Fiber web through an asymmetric heating course in the manufacturing machine with the help of double-row drying groups. This succeeded but only inadequate.

divided one the fibrous web, in particular paper web in the z-direction, the is called in the direction of sheet thickness, in different layers, so each one points Layer a more or less strong anisotropy with respect to Fiber orientation in the plane. The layers can each Have fiber main directions, which are characterized in that a certain number of fibers are aligned in the same direction is. Fibrous main directions can exactly in the machine main direction or across it or in directions show in between. How many fibers in a common direction show, press differ in the degree of anisotropy. High anisotropy means many fibers are oriented in one direction and vice versa. The anisotropy of the fiber layers also determines the anisotropy of the mechanical properties, e.g. the strength anisotropy in the level. The anisotropy or the degree of anisotropy can be different in the layers. Then one speaks of one not constant profile of the layer orientation measured over the Sheet thickness, ie in the z-direction.

One Measure for the different ones Layer orientation in z-direction can, for example, the ratio of Breaking length ratios the upper half of the sheet to lower half of the sheet be. This measure should at the end of the paper machine in the range of 0.7 to 1.3, preferably from 0.8 to 1.2. The tenacity ratio, short in the art RLV is the ratio the tear length in the machine direction (MD direction) and the tear length in the cross-machine direction (CD direction). This can be for the entire fibrous web or, after splitting the fibrous web in layers, also for each layer will be determined.

One Profile of the layer orientation manifests itself in particular in a two-sidedness, that is, a different layer orientation on the leaf top and on the leaf underside. Such Two-sidedness can arise due to the asymmetrical structure of the headbox nozzles. In the flow deflection At the diaphragm, the fibers are increasingly aligned in the machine direction. On the opposite Lower lip side finds an alignment in the machine direction by the increased microturbulence only limited instead of.

Also through the former, the press section and the dryer section in one Paper machine can be a two-sided layer orientation between the sheet top and leaf underside.

Of the Invention is based on the object, an apparatus and a method to improve the type mentioned. In particular, the properties should the fibrous web, in particular the curl of the fibrous web, be improved.

These Task is characterized in a device of the type mentioned by solved, that the design and / or operation of the headbox alone or in combination with the design and / or operation at least one further component is selected so that a desired profile the layer orientation in the z direction with respect to a curl influence the fibrous web results.

at a method of the type mentioned, the task is characterized solved, that the design and / or operation of the headbox alone or in combination with the design and / or operation at least one further component is selected so that a desired Profile of the layer orientation in the z-direction with regard to a curl influence the fibrous web results.

The inventors have recognized that the headbox, the former, the press section, the dryer section and other components of the production machine are based on the structure of the pulp impact on curl inclination in different ways. While the headbox and the former can mainly negatively affect the fiber layer of the fibrous web, the press section, for example, has an effect on the composition of the fibrous web in the z-direction. For example, a different ratio of fibers and fillers on the top and bottom of the fibrous web may adversely affect curl due to these structural differences.

The Inventors have found that this is not known Activities, as the adjustment of the heating process in the dryer section, corrected can be. Rather, the headbox offers the adapted Influencing the layer orientation by shaping its flow space a correction option, so in the later Use of fibrous web only minimal or no curl more occurs.

As well it was found that trains or expansions of the fibrous web during the transfer from one component of the manufacturing machine to the other the structure the fibrous web negatively influence with respect to Curlverhalten.

Thus, according to the invention proposed, the known influence of the headbox and at least another component on the profile of the layer orientation to use specifically by a headbox with a specific Influence on this profile is combined with at least one another component whose influence on the said profile is the Counteracts or supports the influence of the headbox ever after whether according to a preferred embodiment of the invention a to the median plane of the fibrous web symmetric layer orientation required is or in certain cases one asymmetric layer orientation. An asymmetric layer orientation can be for example Certain paper types may be preferred or chosen to have an impact another component of the paper machine on the profile of Balance layer orientation.

there The selection is preferably made so that the front of the coater a desired, preferably does not give any curl tendency in the fibrous web and / or that in the finished fibrous web a desired, preferably no curl tendency results.

To An embodiment of the invention, a shaper with a on be combined with the top of the fibrous web forming roll with a headbox that has a correspondingly asymmetric layer orientation causes. In the area of the forming roller finds the largest part the drainage instead, making this element a major influence on the fiber orientation Has. Since only on the side of the forming roll vacuum is present, the one-sided leads Vacuum to a different level of orientation on the upper and the underside of the fibrous web. This is compounded when Formierauger after Formierwalze with its vacuum on the same side is arranged as the forming roller. As the vacuum level too influences other paper properties such as formation and dry content, The vacuum can not be used alone to set a desired Profiles of the layer orientation are used. A desired Profile of the layer orientation can therefore only by the combination of the invention of the former with a headbox with corresponding asymmetric Layer orientation can be achieved.

to The asymmetric layer orientation can cause the headbox in particular an asymmetrical nozzle and / or an asymmetric lameilen arrangement exhibit. Alternatively or in addition the headbox can be constructed in two or more layers and in different layers with different layer speed operate. Due to the different film speeds also results in a different layer orientation, since the fiber orientation also increases with increasing flow velocity increases.

To Another embodiment of the invention is a former with a arranged on the underside of the fibrous web forming roll combined with a headbox that has a symmetric layer orientation causes. It has been found that such trained shaper create a symmetric layer orientation. By combination with a headbox, which also has a symmetric layer orientation can give a symmetrical layer orientation in total produced fibrous web are produced. This results in advantageously also symmetrical properties of the fibrous web.

A symmetrical layer orientation through the head box can be achieved in particular by the fact that the headbox has a symmetrical nozzle and a symmetrical lamellar arrangement or an asymmetric nozzle and a correspondingly inversely asymmetrical lamellar arrangement. Another possibility is to compensate for an asymmetry of the nozzle and / or the fins of the headbox by different flow velocities in the layers of the headbox in a two- or multi-layered headbox. As already mentioned, an increased flow velocity or shear flow leads to a higher orientation of the fibers, so that a lower orientation tion of the fibers can be compensated by the geometric design of the headbox in a layer by a correspondingly increased flow rate in this layer.

at a method according to the invention the headbox on the one hand and / or the former on the other hand or only the headbox in dependence configured by the machine configuration in the manner described above and combined with each other. The solution is particularly advantageous in the production of copy paper, in particular wood-free Pulp fibers, apply.

The previously described types of formers are from the group the twin-wire former and, in particular, the sub-group of roll-blade shapers, where the first drainage element a rotating drainage element, such as a forming roll, that is an open roll, is. This drainage element can be operated with or without vacuum.

The However, the invention also relates to formers in which the forming roll through a stationary one Dewatering element, such as an aspirated or not aspirated, and preferably curved Shoe, is formed. In the further drainage process can in this Former type follow at least one evacuated forming roller.

The The invention can also be applied to a so-called hybrid former Find. This former type is characterized in that the twin-wire zone only after a Einsiebzone follows. in this are sucking Elements for drainage used. An asymmetric layer orientation is the result. in the Double-sieve area can turn at least one forming roll or suction roll and stationary drainage elements consequences.

As well The invention is in Langsiebformern exclusively for drain one side and thus - ever at the option of the drainage process - one more or less asymmetric layer orientation, applicable.

at a two- or multi-layer headbox is the layer speed according to one embodiment of the invention by an average speed set symmetrically. So that means that at a desired Speed difference of 10 m / min the upper layer for example increased by 5 m / min Speed and the lower layer lowered by 5 m / min Speed. This has the advantage that the volume flow overall unchanged remains and thus the basis weight not changed becomes. It is therefore not a correction of the consistency over the lip opening necessary. Rather, the lip opening can continue alone Adjustment of fabric density can be used in the layers. The Layer velocity difference and the fabric densities in the layers can so independent be adjusted from each other.

To a further embodiment of the invention is additionally in the selection Difference of over all layers averaged layer speed and screen speed considered. It has been shown that this difference affects the possible change has the profile of the layer orientation. And that is the effect of a Difference in the layer speeds the greater, depending smaller the difference of the averaged layer velocity and the screen speed is.

Prefers the difference is set to a maximum of +/- 100 m / min, preferably maximum +/- 50 m / min. This is a good influence on the profile of the layer orientation guaranteed.

To Another embodiment of the invention is in a two- or multilayer headbox the difference in layer velocities between the individual layers to a maximum of 100 m / min, preferably to a maximum 60 m / min. With that you can Sheet formation disorders be avoided.

With the invention is preferably a ratio of the breaking length ratios between leaf top and leaf underside of 1 +/- 0.5, in particular 1 +/- 0.2 set. These values have proven to be suitable and advantageous exposed.

Also has proven to be suitable and advantageous, a supernatant a respective rigid blade in a two- or multi-layer headbox over the Nozzle mouth of +/- 60 mm, preferably> 0 mm.

The The above-described variations apply correspondingly to the method according to the invention.

embodiments The invention is illustrated in the drawings and will be described below described. They show, in each case in a schematic representation,

1a a first former design;

2 B a second former design;

3c a third shaper design;

4a to 16a different variants of a headbox;

1b to 16b the respective associated distribution of the layer orientation on the paper top and bottom side;

17a to 17d other variants of a headbox with a directly flanged manifold;

18 an advantageous machine configuration for the production of curlar and woodfree copy papers; and

19 a combination of another variant of a headbox with a former.

The in 1a Shaper shown is part of a paper machine with a headbox 1 , the former shaper 2 , a subsequent press section 3 , of which only the beginning is shown, as well as other components such as dryer section, optionally coater and calender. The shaper 2 includes one in a lower sieve loop 4 arranged forming roller 5 and one in a top wire loop 6 arranged Formiersauger 6 , bottom wire 4 and top wire loop 6 are also each about pulleys 8th guided. In addition, in the lower sieve loop 4 another suction device 9 and a sieve suction roll 10 arranged. About a pickup roller 11 that already to the press section 3 heard, the fibrous web is from the bottom wire 4 removed from the former and the press section 3 fed. As you can see, in this variant is the forming roller 5 So arranged on the underside of the fibrous web.

In 1b is shown that such a Shaper design results in a symmetric layer orientation. The jet velocity is greater than the sieve speed.

At the in 2a variant shown is the forming roller 5 in the upper sieve loop 6 arranged. This is indicated by the lower sieve loop 4 the Formiersauger 7 on. Both sieve loops 4 and 6 are again each about pulleys 8th guided, and there are also a suction device here 9 and a sieve suction roll 10 provided, wherein the suction device 9 This time in the upper sieve loop 6 and the suction sieve 10 again in the lower sieve loop 4 located. The web removal to the press section is also done here by a pickup roller 11 in a felt loop 12 is arranged. In the variant of 2 is the forming roller 5 So on the top of the fibrous web.

In 2 B is shown that results from such a former design an asymmetric layer orientation. The jet velocity is greater than the sieve speed.

Also in the variant of 3a is the forming roller 5 on top of the fibrous web. The difference to the variant of 2 only consists in that also the Formiersauger 7 on the top of the fibrous web, so in the upper wire loop 6 is located while the suction device 9 in the lower sieve loop 4 is arranged. Incidentally, this variant agrees with the variant of 2 match.

In 3b is shown that results from such a former design an asymmetric layer orientation. The jet velocity is greater than the sieve speed.

As mentioned at the beginning, can in the 1a . 2a and 3a Forming roller shown 5 also be formed by a stationary dewatering element, such as a suctioned or not vacuumed and preferably curved shoe. In the further dewatering process, at least one evacuated forming roller can then follow.

In the 4a illustrated first variant of a headbox 1 has an asymmetrical nozzle 13 with a panel 14 on the top and a protruding lower lip 15 on the bottom up. In addition, the headbox of this first variant has symmetrically arranged lamellae 16 on.

In 4b is shown that results from such a design of the headbox an asymmetric layer orientation, namely a high anisotropy in the upper half 17 and a lower anisotropy in the lower half 18 the fibrous web. That is, the fibers in the top half 17 have a main fiber layer direction, while in the lower half no such direction is preferred.

In the second headbox variant of 5a the nozzle design agrees with that of 4a match. In contrast to the first variant, the slats 16 here, however, arranged asymmetrically. As in 5b shown, results from the combination of an asymmetric nozzle 13 with inverted asymmetric lamellae 16 a symmetric layer orientation.

In the variants of 6a and 7a are both the nozzles 13 as well as the lamellae formed symmetrically. Accordingly, as shown in the 6b and 7b shown, a symmetric layer orientation.

The same applies to the variant of 8a that differ from the variant according to 6a only by an additional flexible separating element 19 in the middle of the headbox is different. 8b again shows the symmetric layer orientation.

Also the variant of 9a has a flexible separator 19 on. However, the nozzle design here is asymmetrical, so that as in 9b shown, gives an asymmetric layer orientation.

In 10a Another variant is shown, depending on the variant 9a only differs in that here the lamellae are reversely arranged asymmetrically. As a result, the asymmetrical nozzle design is compensated, so that according to 10b gives a symmetric layer orientation.

The subsequent machine configuration may necessitate the asymmetry in 9a even to reinforce. This can be achieved by placing in the lower half of the nozzle 13 longer slats 16 than in the upper half of the nozzle 13 be used.

11a agrees largely with 8a match. The flexible separating element 19 is only by a rigid separator 20 replaced. According to 11b Consequently, a symmetrical layer orientation also results here.

rigidity Separators are generally used to separate the nozzle space used in at least two nozzle subspaces, in which different pressures for the purpose of generating different respective jet speeds can be obtained.

12a differs from the variant according to 11a by an asymmetrical lamellar arrangement, so that according to 12b also gives an asymmetric layer orientation.

In 13a is again a variant with a rigid separating element 20 shown in which an asymmetrical nozzle 13 with inverted asymmetric lamellae 16 combined, resulting in a symmetric layer orientation.

The preferably long and short lamellae 16 in the two nozzle subspaces of the nozzle 13 move in certain length ranges relative to the corresponding aperture 14 especially with the convergent nozzles. The long slats 16 , either flexible or stiff, bend in the range of +/- 30 mm to the aperture. The short slats 16 are shorter in all cases. They are preferably in the range of less than -30 to -150 mm, in particular in the range of less than -50 to -100 mm.

14a shows a variant with a rigid separating element 20 , asymmetric nozzle 13 and symmetrical lamellae 16 , This results in an asymmetric layer orientation.

15a again shows the variant of 11a , where additionally according to arrows 21 and 22 It is shown that the flow velocities v1 and v2 in the upper half of the headbox and in the lower half of the headbox can be chosen differently. In the 15b1 , b2 and b3 show how the layer orientations are adjusted as a function of the speed ratios. 15b1 shows the case that velocities v1 and v2 are the same 15b2 shows the case that the speed v1 in the upper half of the headbox is greater than the speed v2 in the lower half and 15b3 the opposite case. Accordingly, according to 15b1 a symmetric layer orientation, according to 15b2 an asymmetric layer orientation with high anisotropy in the upper half of the fibrous web and according to 15b3 an asymmetric layer orientation with high anisotropy in the lower half of the fibrous web.

16a shows a further variant of a headbox with two rigid separating elements. Accordingly, three different speeds v1, v2 and v3 can be set. If all velocities v1 to v3 are set the same, a uniform layer orientation results over the thickness of the fibrous web, as in 16a shown. By appropriate different choice of the speeds v1 to v3, the layer orientation can be selected in the desired manner, in particular also different on the top 17 , the bottom 18 and in the middle 24 the fibrous web.

17a to 17d Finally show further different variants of a headbox with a directly flanged manifold. The supply of the respective system thus takes place from a manifold.

In the in the 17a Due to the position of the separating lamella, different flow velocities in the individual layers can be set and thus the layer orientation can be influenced.

The flow rates in the individual layers can be adjusted in different ways. On the one hand, the friction conditions of the flow in the individual layers of the nozzle can be influenced. For example, as in 17a through the double arrow 26 indicated by means of a pivoting of the rigid blade 27 from the neutral position out and / or by a change in the flow resistance in the respective upstream of the nozzle turbulence generators T1, T2. This is particularly advantageous when both layers are supplied by a distributor tube.

It is also conceivable, each layer separately with pulp suspension to provide, for example, over separate distribution pipes. The throughput is tax related adjustable.

Is possible also influencing the layer orientation by setting different beam contractions in the two layers, for example, by adjusting different dazzle boards and / or different aperture angle.

Conceivable are also adjustable in length Slats and / or shape changeable Slats for targeted change the fluid friction conditions to change the flow rates in the respective layers and thus to adjust the layer orientation. Increase long slats the friction and support thereby the anisotropy of the fiber layer, as well as a possible thickening a lamella and the consequent narrowing of a flow channel.

In the in the 17b illustrated headbox with rigid separating blade 27 can by the position of the lip support 28 . 29 set different flow velocities in the individual layers and thus the layer orientation can be influenced. The positioning of the lip supports 28 . 29 For example, by a respective pivoting (double arrows 30 . 31 ) when changing the lip openings.

By Change the throughput becomes the existing driving pressure gradient more or less in the nozzle relocated. This results in different jet speeds. For example, bringing an increase the gap opening by 5% (5% throughput reduction) an increase in pressure loss 10.25% in one shift. This means at a pressure drop of 500 mbar a pressure reduction of 50 mbar. This achieves depending on the jet speed, for example, at 1200 m / min, a relevant change in the differential speed, for example, about -15 m / min.

The Indian 17c Headbox presented basically makes a combination of the headboxes of the two 17a and 17b A change in the pressure loss in the turbulence generator T1, T2 can be done by actively changing the flow cross-section, for example by inserting or replacing inserts, by valves and / or valves, of one or more rows in one or both layers. Preferably, the control is performed on one side of a line, since the flow differences in the percentage range at the nozzle start are not relevant, have a strong impact in the area of sheet formation in the percent range. The control of the jet velocity is carried out by a dynamic pressure control by pressure transmitter in each layer.

And in the in the 17d headbox is a further development of in the 17c illustrated headbox. The illustrated headbox also has a known to the expert Siebwasserdosierungssystem 32 , as for example in the German patent DE 40 19 593 C2 is described.

In particular for writing and printing papers and especially for copying papers made of wood-free pulp fibers, press concepts with, in particular, an extended press nip (shoe press) can be advantageously used. In these types of press, despite the exercise of a pressing operation, the specific volume, the so-called bulk, can be obtained. A possible press concept with only one long press nip with a press nip length> 300 mm, preferably> 400 mm, is, for example, in the German Offenlegungsschriften DE 10 2004 050 593 A1 or DE 10 2004 039 785 A1 described.

Farther can also two successive press nips be beneficial. Here you can both press nips be formed from shoe presses. Especially at wood-free papers represents a press concept with two press nips, wherein the first press nip is a nip press nip and the second press nip Press nip is a shoe press nip, a volume-saving combination The nip press nip is for example by an overhead and deflection-controlled roller and by an opposite Saugpresswalze formed. Because the fibrous web has a dry content of less than 25% at the inlet into the press section, are only small compression pressures necessary to relatively large To drain water. These can be easy discharged through the suction press roll become.

Likewise, the use of a so-called compact press is possible, wherein in the first and / or third press nip a shoe press can be provided. Such a press concept is for example in the German patent application DE 198 00 807 A1 described.

An exemplary and advantageous machine configuration 100 for the production of curlarms and woodfree copy papers with a high specific volume is in the 18 shown. The machine configuration 100 is shown in a total of four partial representations, which are marked with the following arrows A, B and C in terms of their sequence.

The pulp suspension 101 is over a two-layer headbox 102 a shaper 103 in the embodiment of a twin-wire former leads, taking in each layer of the headbox 102 Fibrous suspension 101 from the same source 104 is supplied. The headbox 102 also has a rigid separating blade 105 on, coming out of the nozzle 106 protrudes and thus divides it in half. Each half is with flexible blades 107 . 108 between each line of the associated turbulence generator 109 . 110 stocked. These flexible slats 107 . 108 ends inside the nozzle 106 and are symmetrically populated in this example, moreover, two apertures 111 . 112 are provided.

The shaper 103 comprises a forming roller 113 and a Formiersauger 114 that are not arranged on the same side.

The Indian 18 Shaper shown in a suitable manner with in the 4a to 16a and 17a to 17d Headbox variants are combined. Furthermore, the shaper shown also as a in the 1a . 2a and 3a be performed executed form variant.

After the shaper 103 becomes the fibrous web 115 to a press section 116 transferred. The press section 116 consists of a first nip press 117 with top and deflection-controlled roller 118 and bottom suction roll 119 , The second and last press nip 120 is by a shoe roller 121 . 122 educated.

The fibrous web 115 is now using a transfer tape 123 to a so-called impingement drying device 124 , as for example from the already mentioned German Offenlegungsschrift DE 10 2004 039 785 A1 is known, transferred. The advantage here is the closed web guide up to a dry content of over 60% or 63%. This allows a high production speed for this fibrous web 115 of ≥ 1,500 m / min, in particular ≥ 1,650 m / min.

This is followed by a known single-row (pre-) dryer section 125 with several drying groups 126 , Essential for high production speeds is a supported and by stabilizers 127 between the drying cylinders 128 equipped track guide.

Following the pre-drying section 125 At least one coater follows 129 for preferably two-sided and indirect application of a liquid or pasty medium 130 . 131 , especially glue. The order of glue 130 . 131 For example, reduces the dusting of the copy paper in the copier.

After a non-contact deflection 132 and drying 133 the coated fibrous web 115 follows a night dry party 134 that have both single-tier dryer groups 135 as well as double-row drying groups 136 includes. With the help of the double row drying group 136 a symmetrical drying of the double-sided glue application can be achieved. A slightly different glue application on the two sides of the fibrous web 115 would lead to different drying processes and thus in turn to Curlneigung.

Then follows a two-nip calender 137 and a preferably winding tension controlled / surface-sparing reeling in a winding machine 138 , The two-nip calender 137 can also be designed as a calender in general.

The in the 1a . 2a and 3a Former variants shown can now in a suitable manner with in the 4a to 16a . 17a to 17d and 18 Depending on which layer orientation is desired, combined headbox variants are combined. Combinations of multilayer headboxes with the formers of the 1a . 2a and 3a because desired layer orientations can be set in a particularly advantageous manner by the different flow velocities. In particular, the asymmetry of the layer orientation by the shape variants of the 2a and 3a be compensated by correspondingly reversed asymmetric headboxes, while the symmetric shaper of 1a can be combined with a symmetrical headbox to achieve a symmetric layer orientation. However, if an asymmetric layer orientation is to be set, then other combinations can be selected accordingly. In this case, a desired layer orientation can be set by selecting the embodiments of headbox and former according to the invention.

19 shows a two-layer casserole 1 exemplified by a former 2 , of which only two forming rollers 5 each with a sieve loop 4 are shown. The headbox is here with a rigid divider 20 educated. As with arrows 33 and 34 are shown above and below the rigid separator 20 set different film speeds. This results even after leaving the nozzle 13 different film speeds v1 and v2 on the upper side of the sheet and the underside of the sheet. The average speed is shown by arrow vm. The rigid separating element 20 has a projection of +/- 60 mm, preferably> 0 mm, over the nozzle 13 of the headbox 1 on.

The sieves 4 the forming rollers 5 of the For mers 2 have a screen speed vs. The difference between the average speed vm and the screen speed vs is preferably at most 100 m / min, in particular at most 60 m / min. The difference between the layer velocity v1 and the layer velocity v2 is a maximum of 100 m / min, preferably a maximum of 60 m / min. The differences are each set such that a desired profile of the layer orientation results, wherein the difference between the screen speed vs and the average speed vm can be used to set the influence of the difference between the layer speeds v1 and v2 on the profile of the layer orientation.

1

headbox

2

molder

3

press section

4

Lower wire loop

5

forming roll

6

Upper wire loop

7

suction box

8th

idler pulley

9

suction

10

Suction roll

11

Pickup roll

12

dryer

13

jet

14

cover

15

bottom lip

16

lamella

17

top the fibrous web

18

bottom the fibrous web

19

flexible separating element

20

rigid separating element

21

arrow

22

arrow

23

arrow

24

middle layer

26

double arrow

27

rigidity separating lamella

28

lip carrier

29

lip carrier

30

double arrow

31

double arrow

32

Siebwasserdosierungssystem

33

arrow

34

arrow

100

machine configuration

101

Fibrous suspension

102

headbox

103

molder

104

material source

105

rigidity separating lamella

106

jet

107

flexible lamella

108

flexible lamella

109

turbulence generator

110

turbulence generator

111

cover

112

cover

113

forming roll

114

suction box

115

Fibrous web

116

press section

117

First Nip press

118

By bend-controlled roller

119

suction press

120

second press nip

121

shoe roll

122

shoe roll

123

transfer tape

124

Impingement drying device

125

pre-dryer

126

drying group

127

stabilizer

128

drying cylinders

129

coater

130

medium

131

medium

132

contactless redirection

133

desiccation

134

Afterdryers

135

Single row drying group

136

Double row drying group

137

Two-nip calender

138

winder

A

follow arrow

B

follow arrow

C

follow arrow

T1

turbulence generator

T2

turbulence generator

ULV

Lower lip Board

v1 to v3

flow rates

vm

middle flow rate

vs

wire speed

z

thickness direction the fibrous web

Claims (38)

Device for producing a fibrous web ( 115 ), in particular paper web, with a headbox ( 1 ; 102 ) and other constituents, such as formers ( 2 ; 103 ), Press section ( 3 ; 116 ), Dryer section ( 125 . 134 ), Coating device ( 129 ) and / or calenders ( 137 ), characterized in that the design and / or the operation of the headbox ( 1 ; 102 ) alone or in combination with the design and / or the operation of at least one further component is selected so that a desired profile of the layer orientation in the z-direction with respect to a curl influencing the fibrous web ( 115 ). Apparatus according to claim 1, characterized in that the selection is made such that a to the median plane in the z-direction of the fibrous web ( 115 ) symmetrical layer orientation he gives. Apparatus according to claim 1 or 2, characterized in that the selection is made so that before the coater ( 129 ) a desired, preferably no Curl inclination in the fibrous web ( 115 ). Apparatus according to claim 1, 2 or 3, characterized in that the selection is made so that a desired, preferably no curl tendency in the finished fibrous web ( 115 ). Device according to one of the preceding claims, characterized characterized in that at least one further component of the device with regard to its influence on the profile of the layer orientation included in the selection is. Device according to one of the preceding claims, characterized in that a former ( 2 ; 103 ) with one on the top ( 17 ) of the fibrous web ( 115 ) forming roll ( 5 ; 113 ) is combined with a headbox ( 1 ; 102 ), which causes a corresponding asymmetric layer orientation. Apparatus according to claim 6, characterized in that the headbox ( 1 ; 102 ) to effect asymmetric layer orientation an asymmetrical nozzle ( 13 ; 106 ) and / or an asymmetrical lamella arrangement ( 16 ; 107 . 108 ) and / or a two- or multi-layered structure with different layer speeds (v1 to v3). Apparatus according to claim 6 or 7, characterized in that the former ( 2 ; 103 ) one on the top ( 17 ) or the underside ( 18 ) of the fibrous web ( 115 ) arranged Formiersauger ( 7 ; 114 ) having. Device according to one of claims 1 to 5, characterized in that a former ( 2 ; 103 ) with one on the bottom ( 18 ) of the fibrous web ( 115 ) forming roll ( 5 ; 113 ) is combined with a headbox ( 1 ; 102 ), which causes a symmetric layer orientation. Apparatus according to claim 9, characterized in that the headbox ( 1 ; 102 ) a symmetrical nozzle ( 13 ; 106 ) and a symmetrical lamella arrangement ( 16 ; 107 . 108 ) or an asymmetrical nozzle ( 13 ; 106 ) and an inverted asymmetric lamella arrangement ( 16 ; 107 . 108 ) having. Apparatus according to claim 9 or 10, characterized in that the headbox ( 1 ; 102 ) is constructed in one, two or more layers. Apparatus according to claim 11, characterized in that in a two- or multi-layer headbox ( 1 ; 102 ) an asymmetry of the nozzle ( 13 ; 106 ) and / or lamellae ( 16 ; 107 . 108 ) of the headbox is offset by different layer velocities (v1 to v3) of the pulp suspension ( 101 ). Device according to one of the preceding claims, characterized characterized in that the selection is made such that a desired asymmetric Profile of the layer orientation in the z direction results. Device according to one of the preceding claims, characterized in that in a two- or multi-layer headbox ( 1 . 102 ) the layer velocity (v1, v2) is set symmetrically about a mean velocity (vm). Device according to one of the preceding claims, characterized characterized in that, in addition, the difference of the over all layers average film speed (vm) and screen speed (vs) considered is. Device according to claim 15, characterized in that that the difference to a maximum of +/- 100 m / min, preferably a maximum +/- 50 m / min is set. Device according to one of the preceding claims, characterized in that in a two- or multi-layer headbox ( 1 ; 102 ) the difference between the layer velocities (v1, v2, v3) between the individual layers is set to a maximum of 100 m / min, preferably to a maximum of 60 m / min. Device according to one of the preceding claims, characterized characterized in that the ratio the tear length ratios between leaf top and leaf underside to 1 +/- 0.5, in particular 1 +/- 0.2 is set. Device according to one of the preceding claims, characterized in that the projection of a rigid separating element ( 20 ) in a two- or multi-layer headbox ( 1 ) over the nozzle ( 13 ) between +/- 60 mm, preferably> 0 mm. Method for producing a fibrous web ( 115 ), in particular paper web, in which a pulp suspension ( 101 ) by means of a headbox ( 1 ; 102 ) into a former ( 2 ; 103 ) and then by means of other components such as press section ( 3 ; 116 ), Dryer section ( 125 . 134 ) Coating device ( 129 ) and / or calenders ( 137 ), characterized in that the design and / or the operation of the headbox ( 1 ; 102 ) alone or in combination with the design and / or the operation of at least one further constituent is selected so that a desired profile of the layer orientation in the z-direction with respect to a curl influence of the fibrous web ( 115 ). A method according to claim 20, characterized in that the selection is made so that a to the median plane in the z-direction of the fibrous web ( 115 ) gives symmetric layer orientation. Method according to claim 20 or 21, characterized in that the selection is made in such a way that before the coating device ( 129 ) a desired, preferably no Curl inclination in the fibrous web ( 115 ). A method according to claim 20, 21 or 22, characterized in that the selection is made so that a desired, preferably no Curl inclination in the finished fibrous web ( 115 ). Method according to one of claims 20 to 23, characterized that at least one further component of the device in terms of its influence on the profile of the layer orientation in the selection taken into account becomes. Method according to one of claims 20 to 24, characterized in that a former ( 2 ; 103 ) with one on the top ( 17 ) of the fibrous web ( 115 ) forming roll ( 5 ; 113 ) is combined with a headbox ( 1 ; 102 ), which causes an asymmetric layer orientation. Method according to claim 25, characterized in that the headbox ( 1 ; 102 ) for effecting asymmetric layer orientation with an asymmetrical nozzle ( 13 ; 106 ) and / or asymmetrical lamellae ( 16 ; 107 . 108 ) and / or formed in two or more layers, the layer velocities (v1 to v3) of the pulp suspension ( 101 ) are chosen differently according to. Method according to one of claims 20 to 26, characterized in that the former ( 2 ; 103 ) with one on the top ( 17 ) or the underside ( 18 ) of the fibrous web ( 115 ) arranged Formiersauger ( 7 ; 114 ). Method according to one of claims 20 to 27, characterized in that a former ( 2 ; 103 ) with one on the bottom ( 18 ) of the fibrous web ( 115 ) forming roll ( 5 ; 113 ) is combined with a headbox ( 1 ; 102 ), which causes a symmetric layer orientation. A method according to claim 28, characterized in that the headbox ( 1 ; 102 ) with a symmetrical nozzle ( 13 ; 106 ) and a symmetrical lamella arrangement ( 16 . 107 . 108 ) or an asymmetrical nozzle ( 13 ; 106 ) and a correspondingly inversely asymmetric lamella arrangement ( 16 ; 107 . 108 ). Method according to one of claims 20 to 29, characterized in that the headbox ( 1 ; 102 ) is constructed in one, two or more layers. A method according to claim 30, characterized in that in a multilayer headbox ( 1 ; 102 ) the layer velocity (v1 to v3) of the pulp suspension ( 101 ) is selected so that an asymmetry of the nozzle ( 13 ; 106 ) and / or lamellae ( 16 ; 107 . 108 ) of the headbox ( 1 ; 102 ) is compensated. Method according to one of claims 20 to 31, characterized that the selection is made so that a desired gives asymmetrical profile of the layer orientation in the z direction. Method according to one of claims 20 to 32, characterized that in a two- or multi-layer headbox layer speed (v1, v2) are set symmetrically about a mean velocity (vm) becomes. Method according to one of claims 20 to 33, characterized that in the selection in addition the difference of over all layers averaged layer speed (vm) and screen speed (vs) considered becomes. A method according to claim 34, characterized that the difference to a maximum of +/- 100 m / min, preferably a maximum +/- 50 m / min is set. Method according to one of claims 20 to 35, characterized that in a two- or multi-layer headbox the difference the layer velocities (v1, v2, v3) between the individual layers set to a maximum of 100 m / min, preferably to a maximum of 60 m / min becomes. Method according to one of claims 20 to 36, characterized that the ratio the tear length ratios between leaf top and leaf underside to 1 +/- 0.5, in particular 1 +/- 0.2, adjusted becomes. Method according to one of claims 20 to 37, characterized in that a headbox ( 1 ) is used, in which the supernatant of a rigid separating element ( 20 ) over the nozzle ( 13 ) between +/- 60 mm, preferably> 0 mm.