EP2425056A1

EP2425056A1 - Arrangement and method for processing a paper web, in particular a cigarette paper web

Info

Publication number: EP2425056A1
Application number: EP10719264A
Authority: EP
Inventors: Franz Burger
Original assignee: Delfortgroup AG
Current assignee: Delfortgroup AG
Priority date: 2009-04-30
Filing date: 2010-04-30
Publication date: 2012-03-07
Anticipated expiration: 2030-04-30
Also published as: ES2535525T3; US8863657B2; US20120111209A1; KR101738178B1; MY156489A; CN102421963A; PL2425056T3; CN102421963B; CA2758463C; EP2425056B1; DE102009019600A1; BRPI1013913B1; US9333530B2; US20150004321A1; CA2758463A1; BRPI1013913A2; KR20120012976A; WO2010124879A1

Abstract

The invention relates to an arrangement for processing a paper web having a low surface area density not exceeding 70g/m², in particular a cigarette paper web, comprising: an input side, over which the paper web is fed into the arrangement; an output side, over which the paper web leaves the arrangement, wherein the paper web passes the arrangement from input side to output side in a direction of conveyance; a device (5) downstream of the input side, in particular a printing unit, preferably a gravure printing unit, for applying a liquid printing medium to the paper web; a first drying station (7) following the applying station in direction of conveyance, in particular hot-air drying, for drying the printing medium applied to the paper web; a device (9) following the first drying in direction of conveyance for moistening the paper web and a second drying station (11) following the moistening device in direction of conveyance, by which the moistened paper web is dried.

Description

Plant and method for processing a paper web, in particular a cigarette paper web

The invention relates to a system and a method for processing a paper web having an areal density of no more than 70 or 60 g / m ^2, in particular of not more than 50g / m ^2, in particular a cigarette paper web. For example, a web for cigarette paper with a surface density of 20 to 40 g / cm ² can be used. Usually, for reasons of sufficient opacity, the cigarette paper contains a filler, especially calcium carbonate.

There is a need of the cigarette industry to refine the cigarette paper on its surfaces, in particular with regard to resistance to smoldering and ignition. In a so-called Low Ignition Propensity (LIP) cigarette paper clearly demarcated zones are to be implemented on the cigarette paper to reduce the air permeability in these zones to a level that ceases immediately once the cigarette is placed on a solid surface and the glow reaches such a zone. This type of anti-corrosive protection is realized, for example, in that a starch solution is usually applied in a direction perpendicular to the conveying direction stripes on an inner side of the cigarette paper web, namely on the cigarette paper side, which faces the tobacco. The inventors of the subject of the invention have recognized that residual stresses and changes in extensibility of the paper in the course of the paper web between printed and unprinted areas, ie between areas of starch solution strips and starch solution-free areas, occur which stresses even strike folds in the cigarette paper. Forming the cigarette paper on the one hand poses a problem in the further processing of the cigarette papers, and on the other hand, it leads to an optical deficit which can impair the consumer's acceptance of the article made from this paper and thus can be economically disadvantageous. The printed cigarette paper is usually cut after its starch solution treatment in a cutting station. In particular, due to the changed mechanical properties of the cigarette paper due to the starch solution strips, the maximum throughput of the cigarette paper production process is limited straight through the cutting station, with only very low conveying speeds of only about 50 m / min may be driven.

It is an object of the invention to overcome the disadvantages of the prior art, in particular to provide a plant and a method for processing a paper web having an areal density of at most 60 or 70g / m ² , in particular of at most 50 g / m ² , with which Paper is processed in large quantities, wherein a treatment of the paper, for example, with respect to the corona protection to no optical deterioration of the cigarette paper and the mechanical properties of a treated cigarette paper for a higher production speed to be improved.

This object is solved by the features of claim 1 or 29.

Thereafter, a system for processing a paper web having an areal density of at most 60 or 70 g / m ² , in particular of at most 50 g / m ² , in particular a cigarette paper web, provided, which system has an input side, via which the paper web of the system is fed , Furthermore, the installation has an exit side, via which the paper web leaves the installation, wherein the paper web passes through the installation from the entry side to the exit side in a conveying direction, in particular continuously, preferably with a substantially constant conveying speed. According to the invention the input side of a device, in particular a printing unit, preferably a gravure printing plant downstream, which is a liquid printing medium, such as a starch solution in particular for forming a corona, on the paper web, namely only on one side of the paper to apply. To the printing unit includes in the conveying direction, a first drying station, in particular a hot air drying, to which should dry the applied to the paper web pressure medium. If the processing of the paper through the system or the method according to the invention would end at this point, the paper web would become due to structural changes and distortions of the paper and associated changes in mechanical properties, such as ductility, of the paper, especially in the transition region of paper-free and print medium-containing paper sections weakened, which is visually noticeable by wrinkles at the transition region of the paper. In this respect, the invention proposes, following the first drying, a device for moistening the paper web, which now contains the dried printing medium, wherein the moistening device is also followed in the conveying direction by a second drying station, through which the moistened paper web is to be dried again.

The applicator may include a printing technique such as gravure printing. An alternative application technique, such as a film press technique, is also conceivable.

According to the invention, therefore, the printed cigarette paper, which usually suffers from wrinkling, should be smoothed by complete moistening and subsequent drying. Unexpectedly, it has been found that by wetting and then drying the quality of the paper web does not deteriorate, but wrinkled areas between paper medium-containing paper sections can be smoothed without causing warpage and tension on the paper web. With the method according to the invention and the apparatus according to the invention, even more complex image structures, such as image marks, etc., can be printed on paper without unwanted wrinkles forming.

In a preferred embodiment of the invention, the printing unit is adapted to print on the paper web a printing pattern having alternating regions free of printing medium and printing medium. In this case, in particular a stripe pattern can be provided.

In one development of the invention, the pressure medium is an aqueous solution, preferably a starch solution, an emulsion or a suspension.

Preferably, the printing unit is designed as a gravure printing unit and has a impression roller and a pressure cylinder cooperating with the impression roller according to pressure. The printing cylinder may be associated with a receiving the pressure medium trough so that when rotating the printing cylinder is wetted with the liquid printing medium to apply the printing medium as it passes through the paper web through a pressure contact point between the impression cylinder and the impression roller on the paper web. The tub can consist of two Tub sections exist, namely an inner tub and an outer tub. Depending on the diameter of the impression cylinder, work is done with the inner tub or without the inner tub. The inner tub has a smaller volume or smaller dimensions compared to the outer tub. When using small diameter pressure cylinders, it is advantageous to use the smaller inner tub. As a result, a better Schöpfverhalten the cylinder is achieved. For cylinders with a circumference of about 750mm, the inner tub is too small.

In a preferred embodiment of the invention, the printing cylinder has an outer circumference of 400 to 1200 mm.

In a further development of the invention, the hot-air drying takes place without contact with respect to a printed side of the paper web. This may mean that the hot-air drying conveyor rollers, which are also in direct contact with the paper web, but the conveyor rollers should fulfill no drying function, but only perform a conveying function and are only in contact with the unprinted side of the paper web. The transport of the paper by the hot air drying can also be done via a support screen. This sieve is driven by conveyor rollers. The screen is in direct contact with the paper but never in contact with the printed side of the paper.

The hot-air drying may be formed by a flow around the paper web, wherein the circulating air flow should have a temperature of not more than 240 ⁰ C.

In a development of the invention, the moistening device is designed to moisten the entire paper web as it passes through the moistening device. This may mean that the moistening device realizes irrigation or wetting of the paper web along its entire width when passing through the moistening device, wherein all sections of the paper web are moistened accordingly in the conveying of the paper web in its longitudinal direction, in particular on one or both sides. Preferably, the moistening device wets the paper web with an impregnating liquid, which may have a temperature of 15 ° to 75 ° C.

In a preferred embodiment of the invention, the moistening device forms a sump of impregnating liquid, through which sump the paper web is guided or drawn through for wetting it.

Preferably, the moistening device has two rollers that are rotatably mounted so that they can be pressed against each other. In particular, a sump of the impregnating liquid can be formed at the press contact region of the two rolls. Preferably, the rollers should be pressed together with a pressure of at most 3.5 bar.

In a preferred embodiment of the invention, the moistening device for forming the sump of the impregnating liquid has a pump which can convey the impregnating liquid into the press contact region of the two rollers. In this case, a hose line can be connected to the pump, which leads the pumped impregnating liquid towards the press contact region of the two rollers.

In a preferred embodiment of the invention, a periphery of the at least one roller is provided with a coating material, such as ceramic or polytetrafluoroethylene. Other coating materials can be used, which in particular have a low frictional resistance, a homogeneous surface structure, an extreme temperature resistance and a good chemical resistance and are non-adhesive.

In a development of the invention, the moistening device consists of a spraying device for spraying the paper web with the impregnating liquid. The moistening can thus be realized by the impregnating liquid is atomized by nozzles and only in this way reaches the paper web. Also, in addition to the above sump arrangement in which the paper web is exposed to the liquid impregnating agent, the spraying device may be provided. The sump humidification and the spray device can be operated independently or simultaneously. Preferably, the spraying device is arranged downstream of the rollers in the conveying direction, so that, should a sump area be provided at the press contact area of the rollers, the paper web which has already been pre-moistened by the sump can additionally be wetted with liquid by the spraying device, in particular from both sides. In this case, the spraying device may be formed by a tube formed with nozzles, which are arranged extending in the width direction of the paper web such that the paper web is completely moistened when it has passed through the moistening device.

In a preferred embodiment of the invention, a control and / or regulating device is provided in the system, which can adjust in particular the spray pressure and / or a spray quantity of the moistening device. In this case, the control and / or regulating device can access the nozzles of the pipe in a controlled manner.

Alternatively or additionally, the moistening device can be designed as a gravure printing unit that completely moistens the paper web.

In a preferred embodiment of the invention, the impregnating liquid is water, an aqueous solution, an emulsion or a suspension of water-soluble or water-insoluble inorganic or organic compounds. The aqueous solution may have salts, in particular citrates, for adjusting the rate of simmering.

As a further alternative possibility of providing a total humidification of the paper web, it can be realized that a gravure value or a so-called size press is used.

In the device according to the invention and in the case of the invention, it is preferable to ensure that the amount of water applied is at least 10% of the dry pulp. Preferably, the applied volume fraction is between 25% and 50%. It is also possible to apply a water quantity of 100%. As a basic rule when adjusting the amount of impregnating liquid to be applied, it can be stated that the greater the amount of the printing medium applied in the first station, the stronger the paper web is to moisten with the impregnating liquid. Preferably, as an impregnation liquid or humidifying liquid to use water, which may have a temperature between 10 ° and 80 °. Preferably, the temperature for the water is about 25 ° C to 40 ° C. In such a temperature range, the subsequent drying is facilitated, it was additionally surprisingly found that a warmer water at least 40 ° C for humidification even improves the penetration of the pressure medium applied in the print medium in the paper structure and thus less water must be used for humidification ,

In a preferred embodiment of the invention, the second drying station is realized by contact drying in which the moistened paper web is in direct contact with at least one heated drying cylinder or roll, preferably three or four drying cylinders. In this case, heat is transferred to the paper web by contact with the drying cylinders to obtain the dehumidification of the paper web and thus the drying of the paper web. At the same time, the paper web is tensioned within the drying station in such a way that the paper web rests close to the drying cylinders, whereby a simultaneous drying and smoothing is achieved.

Preferably, at least one drying cylinder, in particular at the first drying cylinder in the conveying direction, a hot air dryer hood is provided which at least partially surrounds the drying cylinder, that the paper web is exposed to the drying cylinder a hot air drying current, guided from the inside of the hood.

In this case, a peripheral wall of the drying cylinder, on which rests the paper web, have a temperature of at least about 60 ° C and at most about 180 ° C.

In a preferred embodiment of the invention, the at least one drying roller is cylindrical and in particular has a cylindrical contact outer surface. The drying of the moistened paper web takes place around the cylindrical contact outer surface, in that it bears in a contacting manner in a peripheral region on the cylindrical contact outer surface. The circumferential area which is occupied by the paper web is preferably greater than 90 °, 100 °, 110 ° or 120 °, in particular at least in the case of a drying roller greater than 180 °. Preferably, the cylindrical contact outer surface is smooth and free of elevation. In this way, an ironing effect of the moistened paper web is achieved. It is ensured that a full-surface contact of the paper web along the entire width is realized within the so-called peripheral area. The contact outer surface is consequently profile-free.

In a further development of the invention, at least three drying rollers are provided, which are arranged offset in a vertical height direction. In this case, for example, the first and last drying roller can be at the same horizontal height. The horizontally adjacent drying rollers can partially overlap seen in the height direction, so that the paper web runs back in the conveying direction after delivery of a first drying roller on the second drying roller and from the second drying roller to the third drying roller opposite to the conveying direction.

Preferably, an at least cylindrical drying roll has a diameter of at least 80 cm, preferably less than 2.5 m, with a preferred diameter size being 1.8 m. The at least one drying roller comprises a particularly closed inner cavity, which can be filled with steam or hot air to heat the drying roller. Alternatively, the drying roller can be heated by infrared radiation.

A particular aspect of the invention is to provide a predetermined temperature profile at the at least two drying rollers.

Usually, it would be expected that the temperature of the drying roller increases in the transport direction of the paper web from drying roll to drying roll. According to the invention, the temperature profile of the drying roller to the drying roller in the transport direction is to be set such that the temperature at least remains the same or decreases at least from the first, input-side drying roller to the second drying roller. Initially, the unprinted side of the paper web can come into contact with the first, input-side drying roller and dried. On the subsequent second drying roller then lies the printed side of the paper web. If an increased temperature were present at the second drying roller, under certain circumstances it might happen that the printing medium at the printed areas of the paper web is mixed with the drying agent. glue together. Due to the reduced temperature at the second drying roller, such sticking or thermal reaction of the printed medium is avoided. The temperature of the third drying roller is then set higher than that of the second drying roller to improve the drying efficiency, because again the unprinted side of the paper web comes into contact with the drying surface of the third drying roller. If a fourth drying roller is provided in the drying station, the temperature should be adjusted so that it is again significantly reduced in order to avoid the above-mentioned thermal reaction of the pressure medium. For example, the temperature profile between three drying rollers can be configured as follows:

- first drying roller: 100 ⁰ C;

second drying roller: 95 ° C;

third drying roller: 120 ⁰ C.

If the solids content of the pressure medium is higher, for example, greater than 25% solids content (solvent less than 75%), the following temperature profile in the transport direction for the drying cylinder can be provided:

- first drying cylinder: 95 ° C;

second drying cylinder: 95 ° C;

third drying cylinder: 1 10 ° C.

In this embodiment, it is thus possible to at least equate the first drying cylinder temperature and the second drying cylinder temperature, wherein the third drying cylinder temperature, at which the unprinted side of the paper web comes into contact with the drying cylinder, is significantly increased. Generally, it should be noted that the temperatures on the outside of the drying cylinder should not exceed 150 °, otherwise it may lead to discoloration of the paper web. However, to achieve a sufficient drying effect, a minimum temperature of 60 ° C should be set.

In a preferred embodiment of the invention, a take-up roll is provided on the output side, which is rotationally driven so that the paper web is biased at least during their transport through the second drying station. In addition, on the output side a Abrollwalze be arranged with a wound paper web, can be compensated in the voltages and / or irregularities on the illustrated Abrollwalze by a spring-loaded pendulum system. The pendulum system may also preferably be biased by compressed air and regulated for a corresponding pendulum motion.

As noted above, the invention also relates to a method for processing a paper web having an areal density of 60 or 70 g / m, in particular of at most 50 g / m, in particular a cigarette paper web, in particular on a printing unit, in particular gravure printing, a liquid medium , like a printing medium, is applied to the paper web. Subsequently, the pressure medium applied to the paper web is dried, in particular at a first drying station, in particular at a hot-air drying. Subsequently, the paper web is moistened with a liquid impregnating medium and the moistened paper web is dried in particular at a second drying station.

It is clear that the method according to the invention can proceed according to the mode of operation of the abovementioned installation according to the invention.

Further characteristics, advantages and features of the invention will become apparent from the following description of a preferred embodiment of the invention with reference to the accompanying drawings, in which:

Fig. 1 is a schematic side view of a system according to the invention; Fig. 2 is a schematic detail side view of a printing unit of the system according to the invention; and

Fig. 3 is a schematic detail side view of a humidifying device of the system according to the invention.

In Figure 1, the inventive system for processing a cigarette paper web 2 having a surface density of 24g / m ² to 32g / m ² is provided generally by the reference numeral. 1 The paper processing installation 1 comprises the following essential main stations required: a unwinding station 3, a gravure printing unit 5, a hot air dryer 7, a moistening device 9, a contact dryer 11 and a reeling station 13.

The unwind station 3 comprises a sleeve (not shown in detail) with an inner diameter of about 76 mm, from which the paper web 2 is unrolled. Other inner diameter for the sleeve, for example, of about 120 mm, can be used. The sleeve is rotatably mounted or may be mounted on a correspondingly rotated shaft. Alternatively, the roll of paper may be wound on a steel core suspended in a unwinding device of the unwinding station.

To compensate for stresses on the paper web 2 or irregularities of the material of the paper web 2, a pendulum system 17 may be provided directly to the unwinding station 3, which is biased by compressed air to communicate corresponding tensile biases of the paper web 2. As shown in FIG. 2, the pendulum system 17 is part of the gravure printing unit 5.

At the gravure printing unit 5, the paper web 2 is wetted in strips on one side with a desired starch solution by printing a starch solution onto a paper web page by means of the gravure printing process. The operation of the gravure printing unit 5 will be explained later with reference to FIG. To the gravure printing unit 5 includes the hot air dryer 7, which has a drying length of about 3.25 m. The hot air dryer 7 is designed to produce a heated Umluftströ- mung with a flow rate of 17000 m ³ / h at a maximum temperature of 240 ⁰ C. The hot-air dryer 7 serves to remove possibly introduced with the printing medium in the gravure printing unit 5 solvent. To protect the paper web 2, the latter is transported through a felt through the hot air dryer 7 therethrough. The support of the paper also takes place on the non-printed side of the paper, wherein the printed side is not in contact with components of the hot air dryer 7 during the drying process. The transport of the paper web 2 via a conveyor belt, which is formed for example of felt, which is driven by rollers 21.

To the hot air dryer 7 is followed by a humidifying 9, which is shown in detail in Figure 3 and will be explained later. The moistening device 9 has the task of moistening the paper web 2 over its entire width and length with a liquid impregnating medium. As impregnation medium water, an aqueous solution, emulsion or suspension at a temperature of 15 to 75 ° C can be used. The moistening device 9 can form a sump, which is to be formed, for example, in the contact region between two rollers pressed against one another, of which one or both rollers are exposed to the impregnating medium. Through the sump, the paper web 2 is exposed to the impregnating liquid as the paper web 2 is conveyed through the contact area.

Subsequently, the moistened paper web 2 is fed to a contact dryer 11, which, as can be seen in FIG. 1, essentially consists of three drying cylinders or rollers 23, 25 and 27 which have the same diameter. The drying cylinders 23, 25, 27 are charged with steam, in particular steam, and can be heated up to a maximum temperature of 120 ° C. The purpose of the contact dryer 11 is to remove the liquid portion of the impregnating medium fed to the moistening device 9 from the paper web 2. In this case, the paper web 2 should be in direct contact with the drying cylinder 23, 25, 27, in order to achieve a desired smoothing effect, so that a completely wrinkle-free paper web 2 is realized. In this case, a Bahnfϊihrung the contact drying 11 is preferably designed so that the printed side of the paper only on the second drying cylinder 25 in contact with the latter occurs. The first drying cylinder 23 is therefore not in contact with the printed side of the paper web 2 but with the opposite one. This embodiment is advantageous in that it does not come to a bonding of the printed substances with the surface of the drying cylinder 23. To increase the dryer output at the first drying cylinder 23, the latter is additionally equipped with a hot air hood 61 (T (max.) = 250 ° C., V (air max.) = 12,000 m ³ / h). Thus, the paper is once dried over the contact with the drying cylinder and smoothed, and in addition, in particular, the printed material is dried over the hot air of the drying hood.

The drying cylinders 23 to 27 each have a cylindrical contact outer surface, which is contacted by the wetted paper web 2 for the most part contact. Preferably, the occupied peripheral area of the drying cylinders 23 to 27 is greater than 90 °, 100 ° or 120 °. In the second drying cylinder 25, the circumferential coverage is greater than 180 °.

As can be seen in Figure 1, three drying cylinders 23 to 27 are provided, which are offset from each other in the height direction. In this case, a horizontal distance of the first 23 and third drying cylinder 27 is set such that it is smaller than the diameter of the (intermediate) drying cylinder 25. Thus, there is an area-wise overlapping of the drying cylinders 23 to 25 seen in the height direction, so that when the paper web 2 is discharged from the first drying cylinder 23 to the second drying cylinder 25 and from the second drying cylinder 25 to the third drying cylinder 27, the paper web 2 is returned to the conveying direction comes opposite.

The paper web 2 is biased within the drying station 11 to train to plan to apply the contact outer surface of the drying cylinders 23 to 27.

The contact dryer 1 1 includes a Aufrollstation 13, which has a support cylinder 31 and a winding roller 33. The function of the support cylinder 31 is to impose the necessary tension of the paper web 2, so that a proper winding of the paper web 2 roller on the roll 33 is ensured.

In the following, the gravure printing unit 5 according to FIG. 2 will be discussed in detail. After the paper web 2 is set by the pendulum system 17 under a tensile stress, the paper web 2 of an assembly of impression roller 41 and pressure cylinder 43 is supplied, which is wetted with a liquid pressure medium (not shown). The wetting of the printing cylinder 43 is achieved in that the pressure cylinder 43 passes through its own axis during its rotation process a tub which contains the pressure fluid. The trough may be formed by two trough sections, namely an outer trough 45 and an inner trough 47, which has a smaller volume compared to the outer trough. When using pressure cylinders 43 with a small diameter, it is advantageous to use the inner trough 47 in order to achieve a better tapping behavior of the pressure cylinders 43. The impression roller 41 builds up the necessary mechanical pressure to allow the printing medium to pass from the impression cylinder 43 to the paper web 2. In addition, the impression roller 41 ensures the transport of the paper web 2 through the gravure printing unit 5 therethrough. A squeegee 59 is provided in the vicinity of the printing cylinder 43 to strip excess printing medium from the printing cylinder 43. The paper web 2 leaves the gravure printing unit 5 to the hot air dryer. 7

FIG. 3 shows in detail the moistening device 11, which consists essentially of two rollers 51, 53 which define a contact pressing region 55, through which the paper web 2 is forced. Via a pump, not shown, a sump of impregnating liquid is formed in the contact pressing area 55 in order to wet the entire paper web 2 with the impregnating liquid.

Alternatively or optionally, in addition to the sump formation at the contact pressing area 55, a spray tube 57 may subsequently be provided, which may be arranged either on one side of the paper web 2 or on both sides (not shown). The spray tube 57 has a plurality of nozzles from which the impregnating liquid is sprayed onto the paper web 2 in order to realize a complete wetting of the paper web 2 with impregnating liquid.

Subsequently, the moistened paper web 2 leaves the moistening device 11 for its drying and smoothing treatment in the contact dryer 11. After the contact drying, it was found that, surprisingly, the paper had no wrinkles and the mechanical properties, such as extensibility, of the paper web 2 were markedly improved, so that substantially higher conveying speeds of up to 600 m / min can be achieved in the subsequent cutting systems. As a result of the impregnation in the moistening device and the contact drying in the contact dryer, the paper printed in the gravure printing method can be further processed as if it were unprinted.

The features disclosed in the foregoing description, the figures and the claims may be of importance both individually and in any combination for the realization of the invention in the various embodiments.

LIST OF REFERENCE NUMBERS

1 paper processing system

2 paper web

3 unwind station

5 gravure printing plant

7 hot air dryers

9 moistening device

13 reeling station

11 contact dryers

17 pendulum system

21 guide rollers

23, 25, 27 drying cylinders

31 supporting cylinders

33 roller

41 Pressur

43 impression cylinder

45 outdoor tub

47 inner tub

51, 53 rolls

55 contact pressing area

57 spray tube

59 squeegee

61 hot air hood

Claims

Plant and method for processing a paper web, in particular a cigarette paper web claims

1. Plant for processing a paper web (2) having an areal density of at most 70 g / m ² , in particular a cigarette paper web, comprising: an input side through which the paper web (2) of the system is supplied, an output side through which the paper web (2 ) leaves the plant, wherein the paper web (2) passes through the system from the input side to the output side in a conveying direction, a device downstream of the input side, in particular printing unit, preferably gravure printing unit (5), for applying a liquid printing medium to the paper web (2), a first drying station following the application device in the conveying direction, in particular a hot-air drying, for drying the printing medium applied to the paper web (2), a device for moistening the paper web (2) following the first drying in the conveying direction and one to the moistening device in the conveying direction subsequent, second drying station, you Which the moistened paper web (2) is dried.

2. Plant according to claim 1, wherein the printing unit imprints a print pattern with alternating print medium-free and with print medium occupied areas on the paper web (2), in particular a stripe pattern is printed.

3. Plant according to claim 1 or 2, wherein the pressure medium is an aqueous solution, preferably a starch solution, an emulsion and / or a suspension.

4. Installation according to one of the preceding claims, in which the printing unit has a press (41) and a printing cylinder (43) cooperating with the impression roller (41) in accordance with pressure, wherein in particular the impression cylinder (43) and / or the impression roller (41 ) is associated with a trough receiving the pressure medium in such a way that, when the pressure cylinder (43) is rotated, it is wetted with the liquid pressure medium in order to increase the pressure medium as it passes through the paper web (2) by a pressure contact point of the printing cylinder (43) and the impression roller (41) aufzudrucken.

5. Plant according to claim 4, wherein the pressure cylinder (43) has an outer circumference of 400 mm to 1200 mm.

6. Plant according to one of the preceding claims, wherein the first drying station, in particular the hot air drying, with respect to a printed side of the paper web (2) takes place without contact.

7. Installation according to one of the preceding claims, wherein the first drying station, in particular the hot air drying, a conveyor belt, such as a sieve which is driven by conveyor rollers, which conveyor belt is in particular only with an unprinted side of the paper web (2) in contact and conveying the paper web (2) through the first drying station.

8. Installation according to one of the preceding claims, wherein the first drying station, in particular the hot air drying, generates a paper web (2) flowing around recirculation flow having a temperature of at most 240 °.

9. Plant according to one of the preceding claims, in which the moistening device wets the entire paper web (2) as it passes through the moistening device.

10. Plant according to one of the preceding claims, wherein the moistening device wets the paper web (2) with an impregnating liquid having a temperature of 15 ° C to 75 ⁰ C.

11. Plant according to one of the preceding claims, in which the moistening device forms a sump of an impregnating liquid, through which the paper web (2) is guided to moisten it.

12. Installation according to one of the preceding claims, wherein the moistening device comprises two rollers (51, 53) which are rotatably mounted such that they abut each other are pressed, wherein a sump of an impregnating liquid at a press contact region of the rollers (51, 53) is formed.

13. Plant according to claim 12, wherein the rollers (51, 53) with a pressure of at most 3.5 bar are pressed against each other.

14. Plant according to one of the preceding claims, wherein the moistening device for forming a sump of an impregnating liquid has a pump which promotes the impregnating liquid in the press contact area.

15. Plant according to one of claims 12 to 14, wherein a periphery of at least one roller with a coating material, such as ceramic or polytetrafluoroethylene, is provided.

16. Installation according to one of the preceding claims, wherein the moistening device comprises a spraying device for spraying the paper web (2) with a impregnating liquid.

17. Plant according to claim 16, wherein the spraying device is arranged downstream of the rollers (51, 53) in the conveying direction.

18. Plant according to claim 16 or 17, wherein the spraying device is formed by a nozzle-provided tube, which is arranged so as to extend in the width direction of the paper web (2) that the paper web (2) is completely moistened.

19. Plant according to one of claims 16 to 18, wherein a spray pressure and / or a spray quantity by a control and / or regulating device is adjustable.

20. Plant according to one of claims 16 to 19, wherein the impregnating liquid is water, an aqueous solution, an emulsion or a suspension.

21. Plant according to one of the preceding claims, wherein the second drying station is realized by a contact drying, in which the moistened paper web (2) in in direct contact with at least one heated drying roll (23, 25, 27), preferably three or four drying rolls (23, 25, 27).

22. Plant according to claim 21, wherein a peripheral wall of the drying roller (23) on which the paper web (2) rests, is heated to a temperature of at most 180 ° C.

23. Plant according to claim 21 or 22, wherein at least one of the drying roller is surrounded by a hood at least partially radially, which at least partially passes a hot air flow to the at least one drying roller (23, 25, 27), in particular only those drying roller with a Hood is provided, which immediately follows an entrance of a second drying station.

24. Plant according to one of claims 21 to 23, wherein the at least one drying roller is cylindrical and in particular has a cylindrical contact outer surface around which the wetted paper web (2) in a peripheral region, preferably greater than 90 °, 100 °, 110th ° or 120 °, in particular at least one of the drying rollers is greater than 180 °.

25. Installation according to claim 24, wherein the cylindrical contact outer surface is smooth, so that in particular a full-surface contact of the paper web is realized along its entire width within the peripheral region.

26. Plant according to one of claims 21 to 25, wherein at least three drying rollers are provided, which are arranged offset in a vertical height direction, wherein the horizontally adjacent drying rollers seen in the vertical direction partially overlap.

27. Installation according to one of the preceding claims, wherein on the output side, a winding roller (33) is provided, which is rotationally driven such that the paper web (2) is biased at least during their transport through the second drying station.

28. Plant according to one of the preceding claims, wherein on the output side a Abrollwalze with a wound-up paper web (2) is arranged, Irregularities of the paper web on the unwound rolling roller are compensated by a tensioned by compressed air pendulum system (17).

29. A method for processing a paper web (2) having an areal density of at most 70 g / m, in particular a cigarette paper web, in particular on a printing unit, in particular gravure printing unit (5), a liquid medium, preferably a printing medium on the paper web (2) is applied in that the printing medium applied to the paper web (2) is dried, in particular at a first drying station, in particular at a hot-air drying, then the paper web (2) is moistened with a liquid impregnating medium and the moistened paper web (2) is dried in particular at a second drying station ,

30. The method of claim 29, which proceeds according to the operation of the trained according to one of claims 1 to 25 system.