WO1994017244A1

WO1994017244A1 - Paper web coating process and device

Info

Publication number: WO1994017244A1
Application number: PCT/EP1994/000239
Authority: WO
Inventors: Rudolf Beisswanger
Original assignee: J. M. Voith Gmbh
Priority date: 1993-01-29
Filing date: 1994-01-28
Publication date: 1994-08-04
Also published as: EP0609483A1; FI99155B; EP0784120A3; FI944496A; EP0609483B1; DE59306972D1; ATE155839T1; JPH07505573A; CA2133311A1; FI944496A0; EP0784120A2

Abstract

A process for coating a low-resistance paper web (based on used paper) has the following characteristics: the paper is coated on both sides; the paper web is dried after coating. The invention is characterized by the following traits: the coating is applied by two or several coating stations; each individual coating stations applies only part of the total amount of coating, and the partial amounts of coating add up at the end of the total coating process to the total amount of coating; the paper web is dried after each partial amount of coating is applied.

Description

Method and device for coating a paper web

The invention relates to a method and an apparatus for coating a paper web. Reference is made to the generic terms of the method claim and the device claim.

The prior art is known from the following publications:

(1) DE-GM 8 414 413

(2) U.S. Patent 2,729,192 (3) U.S. Patent 2,946,307

(4) U.S. Patent 3,084,663

(5) Wochenblatt für Papierfabrikation 1973, pages 164 to 169

(6) Wochenblatt für Papierfabrikation 1978, pages 773 to 778

(7) U.S. Patent 5,112,653

The invention is based on document (1), in particular on its figure 2. Two application rollers are provided which form a nip with one another through which a paper web runs. A nozzle applicator is assigned to each of the application rollers, each applying a coating color film to the outer surface of the roller in question. The nozzle applicator has a nozzle with two nozzle lips, one of which carries a doctor blade at its free end. This is a rod with a grooved outer surface. A metered application of coating color to the outer surface of the roller in question is thus possible. Accordingly, this is an indirect order process, since the bottom line is the

The outer surface of the roller is applied and transferred from there to the paper web.

REPLACEMENT LEAF Waste paper has been used in the manufacture of paper and cardboard for many years, especially with hygienic paper and newsprint. In contrast, the use of waste paper has so far been low for writing and printing paper.

The use of waste paper is very desirable, since waste paper is an abundant pulp that is relatively cheap. On the other hand, the waste paper brings with it technical problems. On the one hand, the strength of papers with a high waste paper input is relatively low, on the other hand, waste paper naturally contains contaminants in the form of dust, which is particularly problematic in offset printing machines. The low strength of scrap base paper containing waste paper makes itself unpleasantly noticeable in the coating process. The coating color contains a high proportion of water in the order of 50% of the total coating color. When brushing, a substantial part of this water penetrates into the paper, whereby its strength naturally drops dramatically. This increases the risk of tearing accordingly. At relatively low

Coating quantities, expressed in g / m ^2, penetrate relatively little water into the paper, so that the reduction in strength is still tolerable. With higher coating color application weights, for example from 5 g / m ² , the risk of tearing increases considerably.

The above-mentioned tendency to dust of waste paper-containing coating tube paper as a second problem factor requires careful selection of the coating method from the large number of possible coating methods.

The invention is based on the object of specifying a method and a device for a paper web of low strength, in particular based on waste paper

REPLACEMENT LEAF to be able to coat high coating color application weights without the risk of tearing.

This object is achieved by the characterizing features of the first method claim and the first device claim.

The invention is explained in more detail with reference to the drawings. The two figures show a schematic representation of two so-called on-machine coaters. The invention is of course also applicable to off-line coaters.

1 shows an end region of a drying section 1 with a multiplicity of drying cylinders, around which a paper web 2 is meandered. The

Dryer section has two rows, i.e. it has a plurality of upper and lower drying cylinders, each arranged in two horizontal rows. When circulating around the individual drying cylinders, the paper web is sandwiched between the outer surface of the drying cylinder in question and a dryer fabric.

The system shown is followed by a smoothing unit, which is designed as a so-called soft nip calendar.

As can then be seen, the paper web is deflected vertically downwards on a deflection roller 4. A number of further deflection rollers 4.1, 4.2, 4.3, 4.4 follow. This is followed by a coating station 5. The coating station 5 comprises two rollers 5.1 and 5.2. These are arranged parallel to one another and together form a nip through which the paper web 2 is passed. The two rollers are arranged such that the roller 5.2 is perpendicular to the roller 5.1. The roller 5.1 is assigned a nozzle applicator 5.3 - see DE-GM 8 414 413. This nozzle applicator 5.3 has two machine-wide nozzle lips, not shown here

REPLACEMENT LEAF on. The second nozzle lip seen in the direction of rotation of roller 5.1 carries a roller doctor with a grooved outer surface. This roller doctor metered the amount of coating color exactly onto the outer surface of the roller 5.1. Exactly this amount of coating color is transferred to the incoming paper web 2 in the nip, and naturally only on one side thereof. A scraper 5.4 is assigned to the roller 5.2. The paper web 2 thus coated on one side passes through the nip, passes around deflecting rollers 4.5, 4.6, 4.7 and 4.8, wherein it passes through a drying station 6, among other things. Apart from other deflecting rollers, a mini drying section 7 then follows, again with drying cylinders. A second coating station 8 follows. This in turn has two rollers 8.1 and 8.2. The roller 8.1 is in turn assigned a nozzle applicator 8.3, which is analogous to that

Nozzle applicator 5.3 is set up. The other side of the paper web is hereby provided with a line.

Another mini dryer group 9 and a rolling device 10 follow.

In this system, painting is carried out in installments in the manner according to the invention. Namely, one side of the paper web is first completely coated in the first coating station 5, and then the other side of the paper web in the second coating station 8. In each case that coating color application weight is applied in the coating station in question which is also the final coating color application weight of the page in question. This subdivision of the coating process ensures that relatively little water gets into the paper during the individual coating processes, and that the reduction in the strength of the paper is therefore also relatively minimal. The strength is immediately increased by the fact that a drying process follows the coating process. The second coating station

REPLACEMENT LEAF is located at such a point at which the paper web has sufficient strength due to the previous drying to survive a new coating process with the appropriate water penetration without tearing.

In this way, coating base papers can be run with a relatively high amount of waste paper and therefore a relatively low initial strength. The coating color application quantities are up to 8 g / m ² .

It is also crucial that, according to the invention, the coating stations defined here are used, in which the paper web is provided with an indirect application by moving the line from the lateral surface of the roller onto the

Paper web is transferred. It is very important that no doctor element has to be attached to the paper web, because the line has already reached its final thickness and dosage on the outer surface of the roller. The selected coating station with its indirect one

Application process ensures that the coated side of the paper web is completely sealed with coating color, so that dust and other particles which adhere to the surface of waste paper-based papers are enveloped in a perfect manner.

Figures la, lb and lc are alternative

Embodiments of the system according to FIG. 1. In each case a distributor element 20.1, 20.2, 20.3 is provided. This can be a round rod of larger or smaller diameter (Fig.la or Fig. Lb), or a rod-shaped body with a non-circular cross-section (Fig. Lc). The distributor element can oscillate in its own longitudinal direction, or in the direction of travel of the paper web, or rotate around its own axis in the case of round distributor elements. Rotating oscillation is also possible. The surface

REPLACEMENT LEAF can be very different, eg completely smooth, polished, grooved, made from all-round wires.

The system shown in FIG. 2 is constructed similarly to the system according to FIG. 1. The end of a two-row cylinder dryer section 1 can also be seen here, furthermore a smoothing unit 3, a first coating station 5, one of these downstream driers 6, a dryer section 7 with drying cylinders, a second coating station 8, another dryer 9, a dryer section 9.1 with drying cylinders as well a reeling station 10.

In contrast to the system according to FIG. 1, the two coating stations 5 and 8 each have two nozzle applicators 5.1, 5.2 or 8.1 and 8.2. This means that the

Paper web 2 can be coated on both sides in that coating station. The dryers 6 and 9 are air dryers which carry the web freely and bring them to such a dry content (if possible at least 70% dry) until the line in the subsequent cylinder dryer sections 7 and 9.1 is touchable.

FIG. 2a shows a modified embodiment of FIG. 2. First, an infrared dryer 30 is provided, followed by a floating dryer (air dryer) 6.9.

The system according to FIG. 3 differs from the system according to FIG. 2 as follows: coating station 5 has only a single application station 5.1, which is assigned to one of the two rollers of coating station 5. Here, too, the coating station 5 is followed by a distributor element 20.5. Coating station 8 also has only a single application station 8.1. A distributor organ 20.6 is connected downstream. The application is therefore only one-sided at each coating station 5 or 8.

REPLACEMENT LEAF The basic idea of painting on rates in accordance with the invention with subsequent drying on rates can be carried out in different ways:

For example, first only one side of the paper web can be coated and then dried, and then the other side of the paper web can be coated and dried.

However, both sides of the paper web can also be coated at the same time, but only with a subset of the total coating.

It is also possible to coat the two sides at the same time, but only one side with a very minimal amount of coating color and the other side with a relatively high amount of coating color, but still not the full amount of coating color that side should come in total.

Combinations are also conceivable, for example from a simultaneous two-sided application with partial weight per side, followed by a further one-sided application in a second coating station, this additional application completing the line on one side, and finally followed by a third coating station, where the dash on the second page is completed. It goes without saying that appropriate drying devices must be provided after each coating process. The selection of the drying process and the corresponding drying device is left to the specialist. For example, he can use infrared dryers, air-guided dryers or cylinder dryers. In the embodiment according to FIG. 2, for example, the dryers 6 and 9 are equipped with such a high drying capacity that no further drying units are required between the coating station and the cylinder drying device.

REPLACEMENT LEAF Figures 4 and 11 show schematically conceivable configurations using the invention. All of these configurations have two coating stations in common. For better clarity, only the essential components of the individual configurations are described in more detail.

4, the paper web is fed in the direction of the arrow from below to a first coating station 1, then to a second coating station 2, a first infrared path 3, a second infrared path 4, a suspension rail dryer 5 and finally a dryer section 6. The first serves Coating station l gluing or pigmenting or pre-coating. This is an indirect coating process, since a nozzle applicator 1.1 first applies the line to one

Applies roller 1.2, which then delivers the line to the paper web.

In the second coating station 2, coating color is first applied directly to the paper web in a first nozzle applicator 2.1, followed by a second nozzle applicator for a particularly short residence time (so-called SDTA principle) with an integrated doctor bar. The construction is designed such that both the first nozzle applicator 2.1 and the second nozzle applicator 2.2 can be pivoted with doctor bars 2.3 if necessary, so that nothing is applied to coating station 2 at all. The situation is similar in the system according to FIG. 5. Here there are one between the first coating station 1 and the second coating station 2

Infrared drying unit 6 and a hot air drying unit 7 interposed.

Figures 4a and 4b represent interesting variants.

The nozzle applicator 2.1 can be a so-called SDTA, for example as in VOITH special print p 2865 11/92 in

REPLACEMENT LEAF Figure 20 shown. This application unit can have a rod-shaped doctor blade with a smooth or profiled outer surface, but also a blade. A so-called "stiff blade" or a "bent blade" can be considered.

Application unit 2.1 can also be a nozzle application unit without a doctor element, for applying the coating color in the free jet as a "curtain" on the paper web (so-called "fountain coating"). Such a commission is in

Figure 19 of the VOITH publication mentioned is shown.

In the embodiment according to FIG. 4b, guide rollers 1.5 and 1.6 are provided before and after the coating station 1 for the purpose of precise adjustment of the wrap angle.

At coating station 1, in the embodiment according to FIG. 4a and FIG. 4b, the counter roller can be moved off.

The special features shown in FIGS. 4a and 4b - in particular with regard to the nozzle design, with respect to the roll lifting and with respect to the upstream and downstream guide rolls - can alternatively also be present in all the embodiments according to FIGS. 5 to 11.

At station 2, instead of the nozzle applicator 2.1, a roller applicator can also be provided.

In any case, in the case of coating station 1, a so-called grinding job on roller 1.2 can be provided in FIG. 4a, with a difference in speed between the web speed and the peripheral speed of roller 1.2. The differential speed can be 0.1 times the web speed, in both directions. The wrap angle of the roller 1.2

REPLACEMENT LEAF through the web will generally be between 5 and 25 °.

6, further components are provided. Coating station 1 has a second nozzle applicator, namely the nozzle applicator 1.3, which is assigned to a roller 1.4. In addition, an infrared drying device 8 is provided on the side opposite the drying devices 6 and 7.

7 corresponds essentially to that according to FIG. 5. However, between the two coating stations 1 and 2 on each side of the paper web there is an infrared drying device and a hot air drying device 6.1, 6.2 and 7.1, 7.2 interposed.

In the embodiment according to FIG. 8, the paper web runs directly through the two coating stations 1 and 2 in a substantially horizontal direction.

Coating station 1 again has an applicator unit 1.1 with an applicator roller 1.2. Coating station 2 is assigned a first nozzle applicator 2.1 and a second nozzle applicator 2.2 with an integrated doctor bar 2.3. This is followed by a suspension railway dryer 5 and finally a dryer group 6.

9 is largely the same as that of FIG. 8. However, an infrared drying device 6 and a hot air drying device 7 are interposed on one side of the paper web between the two coating stations 1 and 2.

The system according to FIG. 10 differs from that according to FIG. 9 by a symmetrical arrangement of the infrared drying device and the hot air drying device.

REPLACEMENT LEAF Facility. Devices 6.1, 6.2 and 7.1, 7.2 can be seen on both sides of the paper web.

The system according to FIG. 11 is the same as that according to FIG. 10 except for coating station 1. This has two

Nozzle applicators 1.1, 1.3, which are assigned to the relevant rollers 1.2, 1.4.

The various configurations shown and described here allow for the most varied

Ways of working too. For example, in the system according to FIG. 4, the intended amount of coating color can be applied with coating station 1, coating station 2 with the nozzle applicator and doctor bar being pivoted away. In the system according to FIG. 8, the intended one

The amount of coating color can be applied with the nozzle applicator 2.1 from coating station 2 alone.

It is also possible to apply a glue suspension in the order of 0.5 to 2.0 g / m ² or pigment suspension in the order of between 2 to 8 g / m ² in the system according to FIG. 4 by means of the nozzle application unit from coating station 1 , followed by a second order at coating station 2 in the order of 4 to 12 g / m ² . The equalization then takes place with a

Line blade or a smooth rod on the downstream doctor bar.

Another variant is the application of a glue or pigment suspension with the nozzle applicator from

Coating station 1. At the second coating station 2, the SDTA nozzle applicator then carries one

Secondary coat layer with a coat weight of 4 to 6 g / m ² , with equalization with the blade or with the rod; the second nozzle applicator 2.1 has left here.

ER _SA TZBLATT 4 operates on the so-called wet-on-wet principle.

The intermediate drying of the line applied with the coating station 1 can be useful. The various infrared drying devices and air drying devices are used for this.

In the system according to FIG. 6, coating station 1 contains, as mentioned, two nozzle applicators 1.1 and 1.3. It is particularly expedient here to immediately add infrared drying and air drying. With this application concept it is possible to simultaneously treat both paper sides with a glue or pigment suspension in coating station 1 and to dry them out to such an extent that the coating in coating station 2 can be touched by the counter roller.

In coating station 2, the top coat for the paper underside can then either with the first nozzle applicator

2.1 or with the downstream SDTA nozzle applicator

2.2 are applied. The leveling is carried out using a blade or a stick. With this variant, i.e. Appendix 6, two construction principles are combined in such a way that their advantages combine, but the disadvantages do not appear. The details are as follows:

Application with a nozzle applicator in an indirect way - i.e. first on the outer surface of a roller, and then on the paper web - has the advantage of the perfect application of coating color without the dreaded squeegee strips. When using waste paper, however, the doctor blade of such a device as a leveling element is problematic.

The design of coating station 2 with a nozzle applicator and coating blade or a rod as a leveling element

REPLACEMENT LEAF leaves no squeegee marks and is ideal for eliminating the so-called film splitting phenomenon.

With such a combined mode of operation, it is thus possible to produce primarily waste paper containing the desired final coat weight. In the first coating station, waste paper containing raw paper is pretreated with the nozzle applicator, while the second coating station with its nozzle applicator and a coating blade ensures the desired coating quality in terms of smoothness, opacity and surface tightness.

In the method according to the invention and the device according to the invention, it may be expedient to take measures to make the film uniform after the stroke in order to avoid the undesirable orange peel effect of the liquid film on the paper web.

The solution to this subtask is that

Application devices are arranged immediately after the nip in the free train of the paper web distribution elements. By means of a relative speed between the paper web on the one hand and the contact surface of the distribution organ on the other hand, these rubbing elements cause the coating slip to be rubbed in the still flowable state in such a way that a self-contained and largely uniformly coated paper web surface is achieved. In particular, this is achieved by a rotating movement of the distribution element and / or its oscillating movement about the longitudinal axis and / or its oscillating movements transversely or longitudinally to the paper web.

Figure 12 shows a two-roll press. A roller 1 and a roller 2, which are arranged axially parallel to one another and rotatably mounted, together form a roller gap 3 for passing a paper web 4. Die

REPLACEMENT LEAF both rollers are driven in opposite directions to each other. An application unit 5, 6 for a flowable medium is arranged laterally next to the part of the roller circumference of each roller 1, 2 which runs from bottom to top. The application device 5 applies coating color and the application device 6 glue to the roller. The paper web 4 is guided from top to bottom through the nip 3. In the areas 7, 8 which the nip forms with the paper web, a film of a flowable medium is applied to the surface of the roll

Paper web applied. By guiding the paper web from top to bottom through the nip, the coating slip or glue is applied to the paper web in the desired thickness. In the subsequent free train 9 of the paper web, a distribution element 10 is arranged on the side of the coating slip. In the case shown, this grater is a rotationally symmetrical body 10a, which is pressed against the paper web coated with coating slip with a certain pressure. This roller is rotatably supported and is driven. It rotates about its own axis in the direction of the paper web or in the opposite direction and, due to a further drive, which is not shown in detail here, performs oscillating movements transversely to the paper web. The paper web is then a deflector, here as

Deflection roller 11a shown, fed to other work facilities.

A total of 11 drive options can be met with this version. Here are the

The main distinguishing features are the direction of rotation in relation to the direction of travel of the paper web and the relative speed between roller rotation and paper web speed.

Rotates the roller in the direction of web travel and the relative speed between the roller circulation and paper web

REPLACEMENT LEAF is zero, a rubbing effect can only be guaranteed if the roller

1) oscillating movements along the paper web,

2) oscillating movements transverse to the paper web, 3) executing a combination of transverse and longitudinal movements with respect to the paper web.

If the rotational speed of the roller is not equal to the paper web speed, i.e. the relative speed between the roller circulation and the paper web is not equal to zero, the corresponding rubbing effect is already achieved by the rotary movement of the roller. It is amplified by the additional oscillation. A superimposition of roller rotation and additional oscillating movement to the paper web enables rubbing in run and across

Direction of the paper web, while the sole rotation of the roller will primarily promote rubbing in the direction of the paper web. In summary, the following options result when a roller rotates in the direction of the paper web and there is one

Relative speed between roller circulation and paper speed:

1) the roller only performs a pure rotational movement,

2) the roller also performs oscillating movements transversely to the paper web,

3) the roller also performs an oscillating movement in the direction of the paper web,

4) the roller performs a combination of longitudinal and transverse movement with respect to the paper web.

If the roller rotates in the opposite direction to the running direction of the paper web, a rubbing effect can only be achieved by the rotation of the roller, but only along the direction of the paper web running. The additional oscillation of the roller transverse to the paper web direction favors the rubbing effect. Oscillating movements along the

REPLACEMENT LEAF Direction of paper web and a combination of longitudinal and transverse movement in relation to the paper web are possible.

The roller is normally driven, either in the same direction or in opposite directions with respect to the paper web. The relative speed required here is set to an optimal value.

If the roller is rotatably supported and is not driven, it can be taken along by the paper web due to its speed. A device that brakes the roller is then necessary in order to achieve the rubbing effect. In addition, it is also expedient here for the roller to have oscillating movements transverse to the direction of the paper web in order to ensure a good rubbing effect over the entire plane of the paper web.

The surface of the roller can be smooth or designed as a profile. Another option is a wire-wrapped roller. Smooth rollers are preferably provided with a Cr cover or paint-repellent and wear-resistant coatings, such as Teflon, rubber, polyurethane or ceramic. The roller diameter is preferably 100 to 400 mm.

FIG. 13 shows a two-roll press analogous to FIG. A roller 1 and a roller 2, which are arranged axially parallel to each other and rotatably mounted and together form a roller gap 3 for passing a paper web 4. The two rollers are driven in opposite directions to each other. An application unit 5, 6 for a flowable medium is arranged laterally next to the part of the roller circumference of each roller 1, 2 which runs from bottom to top. The paper web 4 is guided from top to bottom through the nip 3. A film of flowable medium is applied to the paper web in the areas 7, 8 formed by the nip with the paper web. Both

REPLACEMENT LEAF Application devices apply coating color to the surface of the roller. By guiding the paper web from top to bottom through the nip, the coating slip is applied to the paper web in the desired thickness. In the subsequent free train 9 of the paper web, a grater is arranged on both sides for rubbing the coating slip. These distribution elements, in the case shown rotationally symmetrical bodies 10a, are a rod in the figure. The surface of the rod can be smooth, the diameter is preferably 10-30 mm. It is also possible to wrap the rod with wire or to give its surface a profile.

The rod itself rotates very slowly for the purpose of self-cleaning and to avoid local wear. In order to achieve a good rubbing effect, additional drive options, which are not shown in the figure, are to be provided for the realization of oscillating movements around the rod axis as well as longitudinally in or transversely to the direction of the paper web or a combination of longitudinal and transverse movement relative to the paper web.

In this embodiment it is also possible to use rollers on both sides of the paper web. The execution and design of the drive options is as described in Figure 1.

The distribution elements are preferably arranged on both sides of the paper web so that they are offset from one another in the running direction.

The paper web 4 is passed on to the distribution elements via a deflection device, here a deflection roller 11a. There is also the possibility of avoiding the contact of a still wet or moist, coated paper web with the deflection roller 11a

HE _SA TZ _B LATT Provide drying process between the deflection roller and the grater.

FIG. 14 shows the 2-roll press arrangement already described in FIG. 2 in a modified form. About two axially parallel, rotatably mounted rollers 1 and 2, which are driven in opposite directions to each other and form a nip 3, coating color is applied to the surface of the rollers by two feed devices 5 and 6, one assigned to each roller, and when performing the Paper web 4 applied through the nip 3 to the paper web. In the open train, grating members 10a are also arranged on both sides here. These can be designed as described in FIG. 2 or in FIG. 1. Analogously to this, the drive options as in the figures already described can also be implemented.

The deflection of the paper web takes place here contactlessly via an air cushion deflection device 11b. This has the advantage that even paper webs that are still damp from the coating color can be deflected without directly touching the paper web side that is still wet from coating color with a deflecting element, and prior intermediate drying is not necessary. The paper web is then dried by means of an infrared device 12a. A further possibility for the subsequent drying is shown in FIG. 14b and consists in subjecting the paper web to a suspension drying 12b after the infrared drying 12a.

The structure and function of the 2-roll press arrangement shown in FIG. 15 essentially correspond to the arrangement described in FIG. 2. The reference symbols are assigned accordingly. Rods with a work surface 10b which is convex in their side view, here designed as hydrobar shoes, are used as the distribution elements.

REPLACEMENT LEAF The radius of curvature of the working surface of the rod 10b is preferably chosen to be larger than the radius of the rollers used for it, so that the effective working surface of the grater is larger.

The hydrobar shoes can be stationary or equipped with an additional drive for realizing oscillating movements transverse to the paper web, which is not shown in the figure.

The surface of the hydrobar shoe can be smooth or can be provided with a profile, as illustrated in FIGS. 16 and 17. The profile will preferably not extend over the entire surface of the hydrobar shoe, but only over the first rising curving part in the running direction of the paper web. The following descending part is executed smoothly. This ensures that the top layer of coating slip with its unevenness is roughened and then rubbed evenly. The paper web is then fed via a deflecting member 11 e.g. subsequent drying facilities supplied.

16a, 16b and 16c show possibilities for the profile design. The profile of the work surface shown in FIG. 16a is wavy. Figures 16b and 16c illustrate the possibility of using a rack and a rack profile.

Figures 17a, 17b and 17c give an overview of possible profile contours in plan view. Parallel profile contours, profile contours with a pitch and profile contours with changing pitch are conceivable.

The selection of the distribution organs to be used, their number, i.e. the possibility of series connection of distribution elements on the same paper web side and

REPLACEMENT LEAF the drive options are for a specific application and the effect to be achieved.

REPLACEMENT LEAF

Claims

Process for coating a paper web of low strength (waste paper base) with the following features:

1.1 the paper is coated on both sides;

1.2 the paper web is dried after coating:

characterized by the following features:

1.3 the line is applied by means of two or more coating stations; 1.4 with the individual coating stations only one

Part of the total screed quantity applied, the parts of the individual screed quantities adding up to the total screed quantity at the end of the entire coating process; 1.5 the paper web is dried after each application of a partial coating amount.

2. The method according to claim 1, characterized by the following features: 2.1 eε is first applied to one side of the paper web, the total amount of coating intended for this side;

2.2 then the paper web is dried;

2.3 then the total amount of coating intended for this purpose is applied to the other side of the paper web;

2.4 Then the paper web is dried again.

3. The method according to claim 1, characterized by the following features:

3.1 with at least one coating station is on one side of the paper web only a subset of

E _RSATZB LATT intended total stroke quantity applied for this side;

3.2 then the paper web is dried;

3.3 in a subsequent coating station or in several subsequent coating stations, the missing partial quantity of the total coating quantity provided for this side is applied;

3.4 then the paper web is dried again.

4. The method according to any one of claims 1 to 3, characterized in that the amount of coating per side is 0.5 and 12 g / m ² .

5. The method according to any one of claims 1 to 4, characterized in that the paper web does not fall below a dry content of about 70% at any point in the entire coating process, based on the combined weight of the paper web and the coating.

6. The method according to any one of claims 1 to 5, characterized in that the coating is carried out indirectly in at least one coating station by applying a metered layer to the lateral surface of a roller and then transferring the layer from the roller jacket to the paper web.

7. Device for performing one of the methods according to one of claims 1 to 5, with the following features: 7.1 with a coating station for indirect

To brush; 7.2 the coating station comprises two rollers which are arranged parallel to one another and have a roller gap for passing the paper web, and at least one application nozzle for the metered application of a coating color layer on the lateral surface of the

REPLACEMENT LEAF a roller for transferring this layer from the roller shell to the paper web in the nip;

7.3 with a drying device;

characterized by the following features:

7.4 a plurality of coating stations are provided;

7.5 the individual coating station is designed and constructed such that only a subset of the

Applied quantity is applied;

7.6 A drying device is installed downstream of each coating station.

8. The device according to claim 6, characterized in that each coating station is a double coating station, in which each roller is assigned an order nozzle.

9. Device according to claim 6, characterized in that each coating station is only a single coating station, in which only one of the two rollers is assigned an application nozzle.

10. The device according to claim 6, characterized in that at least one coating station is a double coating station, and at least one coating station is a single coating station.

11. Device according to one of claims 7 to 10, characterized in that on at least one side of the paper web after the nip in the free train (9) there is provided a grater (10a, 10b) which extends essentially over the entire width of the paper web extends.

REPLACEMENT LEAF

12. Device according to one of claims 7 to 11, characterized in that the one application device (5) coating color and the other application device (6) apply glue to the lateral surface of the roller (1, 2) assigned to it, and that the distribution element on the With

Coating color coated side of the paper web is arranged.

13. Device according to one of claims 7 to 12, characterized in that both application devices (5, 6)

Apply coating color to the lateral surfaces of the rollers assigned to it, and that grating elements (10a, 10b) are arranged on both sides of the paper web.

14. Device according to one of claims 7 biε 13, characterized in that the distribution elements (10a, 10b) are arranged on both sides on a common perpendicular to the tangent to the paper web (4).

15. The device according to one of claims 7 to 14, characterized in that the distribution elements (10a, 10b) are arranged on both sides of the paper web offset in the running direction.

16. The device according to one of claims 7 to 15, characterized in that the distribution element is designed as a rotationally symmetrical body (10a).

17. The apparatus according to claim 16, characterized in that the rotationally symmetrical body (10a) is rotatably mounted.

18. Device according to claim 16, characterized in that the rotationally symmetrical body (10a) is drivable.

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19. Device according to one of claims 16 to 18, characterized in that the rotational speed of the rotationally symmetrical body is not equal to the paper speed.

20. Device according to claim 16, characterized in that the rotationally symmetrical body (10a) rotates in the opposite direction to the running direction of the paper web.

21. Device for coating flowable media according to one of claims 7 to 15, characterized in that daε Verreibeorgan is designed as a rod with in the side view convex working surface (10 b).

22. Device according to one of claims 7 to 21, characterized in that the individual distribution element oscillates about its own axis.

23. Device according to one of claims 7 to 22, characterized in that the individual distribution element (10a, 10b) oscillates transversely and / or longitudinally to the paper web.

24. Device according to one of claims 7 to 23, characterized in that the working surface of the individual distribution element (10a, 10b) is smooth.

25. Device according to one of claims 7 to 23, characterized in that the working surface of the individual grater (10a, 10b) is substantially profiled.

REPLACEMENT LEAF