EP1167624A1 - Process for making and further processing of paper - Google Patents

Abstract

During the production of a paper web, data regarding the quality and character of the web are transferred to at least one subsequent finishing station to be taken into account and optimize the finishing process. The finishing station can be a printing press or a formatting station where the paper is cut to size. The information on the paper web can give its mechanical and/or technological characteristics, the paper composition, the longitudinal paper profile and at least one lateral profile. When the rolled paper has been cut, the data are attached to the wound roll. At the printing press, the web shrinkage is noted and taken into account for printing, using the shrinkage values and their locations. Mean values are taken for the lateral shrinkage and/or the longitudinal shrinkage along the web. The mean shrinkage value is used to smooth the fan-out. During printing, the expansion of the paper is locked by the shrinkage relating to the paper quality and the shrinkage compensates for the different lateral paper tensions. The paper production machine has a data set at each drum for the shrinkage values with a sorting key for the drum. The lateral shrinkage values are taken into account at given longitudinal intervals. With a given paper width, for printing, a mean shrinkage value is taken into account in the longitudinal and/or lateral direction and/or the lateral shrinkage. The shrinkage curve which is used is described with a straight or a curved segment and a bending or edge offset value. At least one lateral spreading roller is used to compensate for irregular web tensions. Moisture is used to compensate for irregular web expansions, with a higher degree of wetness for paper zones with a low shrinkage value than where there is a high shrinkage. The paper rolls for printing are structured so that one side the width decreases on a linear line with the paper machine towards the center, and the adjacent roll increases its linear line towards the center. The wound paper roll carries a label with the shrinkage data, or the data is provided separately or it can be transmitted through a data network to the printer.

Description

The invention relates to a method for manufacturing and further processing of paper.

The papermaking process uses a variety of one or more subsequent further processing processes with significant characteristics, mostly mechanical and technological features, of the paper. These change during production also within a particular paper type and across the web width more or less strong. In the respective further processing process, it can is, for example, a printing process, a formatting process, act in particular cutting process, or the like.

For example, the web shrinkage is not just from the latitude position, but also of the fiber properties and the draws in the paper machine dependent.

The aforementioned position-related information about the web properties are not available to the printer. What the shrink the printer knows at most the entire roll width wound shrinkage of an entire roll.

One of the most pressing problems in newspaper printing is different Width expansion behavior of the paper when printing, especially in color printing. The cause lies in the influence of moisture the paper when printing. With multi-color printing, the paper web runs through multiple printing units within a short time. So far the print templates individually for each paper roll the expansion behavior of the paper can be adapted to what is appropriate in the print shop Time and raw material losses.

Individual paper rolls have an individually different moisture expansion behavior on. Paper made on the edge of the paper machine has both greater moisture expansion as well larger tolerance values in this regard.

In paper production, the paper shrinks to completion different dimensions across the web.

Two possible transverse shrinkage curves are shown in FIG. 1. there is the shrinkage in the left area on the driver's side and in the right area of the shrinkage reproduced on the drive side of the paper machine.

In the central area, the shrinkage is usually constant, while the paper increasing towards the two edges shrinking. While according to the upper transverse shrinkage curve shown in Figure 1 the shrinkage in the central area is constant, this becomes Consistency in the central area was not achieved in some cases (cf. the lower one Cross shrinkage curve of Figure 1). Also through different raw material compositions and production process can be a different one Shrinkage behavior arise.

As can also be seen from FIG. 1, the curve shape can be in the edge area be very different, although they are always non-linear in this area is. The middle one is tried through constructive measures expand the constant range as much as possible.

The paper produced in the paper machine is then processed on so-called Drums rolled up. The resulting full drum usually have a width of 2 m to over 10 m and one Diameter from currently up to almost 4 m, the tendency is increasing.

This full reel is initially processed in the paper mill. The paper for newspaper printing is preferably on Roll cutting machines processed into smaller rolls. common are widths from 0.3 m to 1.4 m, sometimes even up to 2.8 m, and Diameters from 0.9 m to 1.5 m, with the trend increasing here too is. Papers for cardboard packaging are mostly used on cross cutting machines cut into individual sheets.

For the sake of simplicity, the following is primarily only on roll paper Referred. However, the same conditions apply to sheet paper.

When printing, the paper expands again transversely to the direction of travel. This expansion (FanOut) is directly related to the shrinkage previously described.

This is how paper stretches across its entire width during production has shrunk constantly, evenly when printing. This FanOut is compensated for, for example, by only partially the printing plates in subsequent printing units be offset by a few 1/10 mm to the edge of the web. Also the targeted expansion of the printing plates, for example with a full surface Color printing is conceivable here.

Paper that does not shrink constantly during its manufacture brings problems with increasing roll width. That's not the reason constant shrinkage in the manufacture of the paper also a non-constant Elongation when printing. Registration problems can only be limited compensated for example by the measures described above become. The extent of printing can range from a few 1/10 mm up to 3 mm or more, depending on the paper and the position being viewed the role. With increasing width of the paper rolls with not constant Cross-shrinkage becomes more difficult, especially with full-surface color printing, to achieve the required quality of the printing result, since the printing plates to achieve the optimal printing result, for example on Edge of the roll should be stretched by 3 mm and then the stretch should fall to 0.3 mm to the middle of the roll, then for the remaining one Half of the roll to be constant at 0.3 mm. Another problem exists the fact that with such rolls an uneven web tension in the Printing press can occur. This is initially due to the non-linear Linear expansion behavior attributed, again by the corresponding Cross shrinkage is caused during manufacture. This uneven web tension increases the risk of tearing on one side and can cause registration problems towards the other edge of the roll and in extreme cases lead to wrinkles.

In a method for influencing known from DE 199 18 399 A1 of the FanOut in a wet offset rotary print is made by measurement on a path of a paper web between a tension roller of a leader in front of several printing cylinders and a pull roller of a pull-out unit behind the printing cylinders a width or transverse expansion of the Paper web determined. The determined width or transverse expansion is for a Drive control used by at least one of the draw rollers to maintain a constant width or transverse extension of the paper web. The Values used for the control are here in the range of Printer measured.

The aim of the invention is to provide an improved method of the aforementioned Way of creating, in particular the ones mentioned above Disadvantages are eliminated.

This object is achieved according to the invention in that for optimization at least one further processing process in papermaking determined information about the respective paper to the respective Subsequent processing process transmitted and taken into account in this become.

The respective further processing process can be, for example a printing process, a formatting process, especially one Act cutting process, and / or the like. Basically it is too possible in several further processing processes already at the Paper production information to be taken into account.

As information obtained during paper production about the respective Paper will preferably have mechanical and / or technological properties transmitted to the respective further processing process and in this is taken into account. These can be, for example Properties such as tensile strength, elongation, gloss, smoothness, Shrinkage, density, fiber orientation, basis weight, moisture, roughness and / or act like.

In certain cases it can also be advantageous if than in papermaking determined information about the respective paper information about the paper components or the paper composition the respective further processing process transmitted and in this with be taken into account. In doing so, the relevant information for example on the type of filler, amount of filler, type of fiber, amount of fiber, obtain chemical additives and / or the like.

According to a further expedient embodiment of the invention Procedures are considered as information obtained in papermaking information on at least one property and / or Longitudinal compositional profile for the respective further processing process transmitted and taken into account in this. there can, for example, transmit "running meter" -related information and be taken into account.

In certain cases it can also be advantageous if at least one Property and / or composition cross profile at the respective Subsequent processing process transmitted and taken into account in this becomes.

According to a further advantageous embodiment of the invention Procedures are considered as information obtained in papermaking information about at least one longitudinal and at least one cross-section of the data relating to the paper web to the the respective further processing process transmitted and taken into account in this. In particular, the transmission of a corresponding one Information grid or network conceivable.

The information obtained in papermaking is preferred after a roll cutting process using data carriers of each Assigned role. The roll cutting process can be particularly in the paper mill occur.

According to a preferred embodiment of the method according to the invention, in which the finishing process is a printing process becomes Optimization of this printing process the one created during paper production Shrinkage of the respective paper when printing accordingly is also taken into account. Advantageous further developments are in the Subclaims specified.

In the subsequent printing, there are therefore paper and position-specific ones Features that correspond to the remote control of the Printing press can be used. Based on the position-specific Information is, for example, a consistently optimal register setting possible.

With the method according to the invention, in particular, the circumstance Be taken into account that the key parameter for the Expansion of moisture when printing in papermaking occurring transverse shrinkage of a paper web.

Based on this individual occurring during papermaking Cross-shrinkage can be the roll-specific expansion of a paper roll be predicted when printing.

• die Rohstoffzusammensetzung des Papiers,
• das Flächengewicht,
• das Rückbefeuchtungsmaß beim Bedrucken,
• die Bahnzüge beim Bedrucken,
• den Längsschrumpf beim Herstellen des Papiers, wobei Längs- und Querschrumpf nicht unabhängig voneinander sind,
• die Bahnzüge beim Aufwickeln an der Papier- und Rollenschneidmaschine und/oder
• die Bahnzüge in der Papiermaschine.

Such a prediction is based, for example, on otherwise constant boundary conditions such as, for example

• the raw material composition of the paper,
• the basis weight,
• the degree of rewetting when printing,
• the web trains when printing,
• the longitudinal shrinkage when producing the paper, the longitudinal and transverse shrinkage not being independent of one another,
• the web trains when winding on the paper and roll cutting machine and / or
• the web trains in the paper machine.

The basic model for the prediction of the expansion can arbitrarily such boundary condition parameters are expanded.

How many parameters are taken into account depends on the intended use from. In the newspaper printing sector, for example, accuracies of, for example, are sufficient a few 1/100 mm. When printing on cardboard boxes are common significantly higher accuracies required.

The shrinking properties of the paper can then be used for printing through suitable measures, both the fan-out and web tension differences be compensated in the transverse direction of the roll.

The transverse shrinkage that occurs when producing a paper web is known. For example, with a Voith Sulzer ModuleJet® Headbox and Profilmatic M® software package Paper machines calculated the cross-shrink curve.

They stand in the transverse direction to the paper web (for example at a distance of approx. 65 mm) Individual values for the cross web shrinkage Available. The corresponding values are given by the Voith Sulzer ModuleJet® constantly updated and recorded.

In the paper mills there is a data record for every drum that is produced created, with a consecutive number, i.e. the so-called "Reel number", serves as a sorting key. In these records are usually the web width and the total paper length of the Drums, basis weight, paper type and some lengthways and Cross profile values stored along with other data. These records serve as a basis for further processing and also for research in the case of Customer complaints. It can be produced individually for example "Square meters" assigned the specific properties concerned become.

According to the invention, the existing data structure can then in particular individual shrink values can be added.

This can be done by, for example, every one kilometer Paper length Cross shrinkage values recorded at a (cross) distance of 10 cm become. Depending on the requirement, other distances are also conceivable. Is the further processing of the paper fixed (e.g. the desired one? Width of a paper roll), both can be an average of the relevant Shrinkage values in the longitudinal and transverse directions as well as the individual transverse shrinkage curve be determined.

This enables the printer to first determine which paper type FanOut the shrinkage value of a paper roll with constant shrinkage equivalent. The factor determined in this way between the shrinkage value and the fan-out can then use it for any further roll of this type of paper and the Compensate FanOut in advance.

For simplification, the shrink curve can e.g. through a straight line or a segment of a circle approximated and a deflection and one Marginal offset value can be described.

Should be a roll of paper with non-constant shrinkage in a print shop parameters are available to the printer, based on which he can correct in a targeted manner.

For newspapers that are not printed in full color, e.g. the role side with the smaller shrinkage values for the colored part. at Papers printed over the entire surface can, for example, expand the Print template from its rectangular basic shape to a trapezoidal shape Using the previously mentioned straight line to describe the shrink curve be compensated to improve the printing result accordingly. The straight line is defined, for example, by the two lying on the edge of the roll Shrinkage values defined. Based on the connection that is already known between shrinkage value and fanout, the printer is able to adjust the pressure plate accordingly.

In order to increase uneven web tension in the transverse direction compensate, among other things a so-called spreader roller is also used become. The paper can wrap around the roller at an obtuse angle. Shows the spreader roller bow towards the tip this obtuse angle, the web train becomes in the middle of the paper web increased to the maximum as it descends towards the edges of the paper web. Does the arc point in the direction of one leg of the obtuse angle or is achieved by swiveling the spreader roller accordingly, that the paper only touches the roller, the web tension distribution remains Paper web largely unchanged. By swiveling the bow Any intermediate values can also exist between these two positions this train train influence can be achieved.

Another way of eliminating uneven paper stretch consists of targeted humidification. With the help of one of the previously known methods for metered application on paper web (such they e.g. can be used in coating machines or coaters) in the Printing press specifically apply moisture to the paper, so that e.g. Paper areas with smaller shrinkage values moistened more are considered paper areas with larger shrinkage values, which again an even expansion of the paper is achieved.

The relevant shrinkage characteristics can be used for packaging, for example of paper in the paper mill noted on the roll label become. It can also in the paper web itself during the production process the paper mill with relevant data. This could be in the The simplest case is that a high-speed printer is used in the edge area Information in the visible wavelength range printed, which are scanned again at the latest when printing become. In principle, any other writing method is also possible conceivable to generate the information in the invisible area and thus have no negative impact on print quality. This Information could not only be in the marginal area of the web, but in each case can also be applied to the edge of a roll.

So far as the location of information on paper is concerned conceivable that this may even be in several places in the paper machine happens at the same time. However, it is also possible, for example, to use this information only when the web is cut crosswise or lengthways e.g. on the edge attach the sheets or rolls. All relevant for the printing process Process steps in papermaking could in this case be linked together in such a way that the relevant information is combined with the position information to the recording device Cutting devices are fed. The advantage of such a design consists in the fact that the printing process is carried out more optimally can and despite a large amount of data a simple and clear Assignment between the respective property characteristic described and the position exists.

Instead of documenting the positional information on the paper web, you can also use a separate data carrier, e.g. a CD-ROM, or via a print shop's data network to provide. In this case, a clear assignment must be made from data record to paper roll or pallet. The special one Another advantage of such a design is the optimization of the Printing process in that the data before entering the web or of the sheet are made available in the printing press and thus also optimization attacks can be used with low dynamics.

After printing, more options for compensation certain negative paper properties are available in particular also border papers are used, which have been compared so far were classified as inferior to paper from the middle range.

The following shrinkage control is conceivable, for example: in reel production are in many cases already the roles or. Arc widths known. Paper shrinkage can now, for example adjusted and / or regulated so that the shrinkage of the Paper of the roll provided for example on the left in the direction of paper travel decreases linearly towards the center of the paper machine, with the neighboring ones Rolling is then constant and finally in the direction of paper travel For example, the role provided on the right increases linearly again. For regulation of the shrinkage can, for example, air on the underside of the felt be blown in. This creates a kind of air cushion between the felt and the paper in the area of which the paper shrinks linearly. The air can, depending on the influence of the moisture profile, directly or by blowing of a drying cylinder. The flow of the Dry felt can be set, for example, using air pressure. Ideally should have such an air cushion in the area of the edge roller width Exception of the outermost edge of the web.

sichtbar:

Farbe

unsichtbar:

punktuell aufgebrachte Feuchtespitze punktuell aufgebrachte Temperaturspitze punktuell aufgebrachtes Wasserzeichen.

Local shrinkage information of the paper web can be determined, for example, by evaluating markings which are applied before the shrinking zone and evaluated after the shrinking zone. The following markings are conceivable, for example:

visible:

colour

invisible:

selectively applied moisture peak, selectively applied temperature peak, selectively applied watermark.

In addition, it is conceivable to mark in front of the shrink zone (Dryer section) and the local shrinkage after the To determine the shrink zone.

An essential idea of the invention is therefore that Data of the paper properties of a paper roll to the printer for optimization of the printing process.

The invention is not only on paper including cardboard, but also basically also applicable to other materials to be printed.

Figur 1

das Querschrumpfverhalten beim Herstellen einer Papierbahn,

Figur 2

eine schematische Darstellung des Schrumpfprofils eines Tambours sowie eine schematische Darstellung zur Erläuterung einer Annäherung der Schrumpfkurve und deren mögliche Beschreibung durch die Kenngrößen Durchbiegung und Randversatz und

Figur 3

eine schematische Darstellung einer um eine Breitstreckwalze geführten Papierbahn.

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

Figure 1

the transverse shrinkage behavior when producing a paper web,

Figure 2

a schematic representation of the shrinkage profile of a reel and a schematic representation to explain an approximation of the shrinkage curve and its possible description by the parameters deflection and edge offset and

Figure 3

is a schematic representation of a paper web guided around a spreader roll.

For example, if the processing is one Printing process, so according to the invention can optimize the printing process the shrinkage of the respective in the paper production Paper are taken into account accordingly when printing.

As can be seen from FIG. 2, the shrinkage curve can be simplified e.g. approximated by a straight line 10 or a circular segment 12 ' and by a deflection and an edge offset value 14 and 16 respectively are described (see FIG. 2).

In this Figure 2 is a schematic representation of the shrink profile SP of a reel, which after cutting into roll formats for example, two straight lines 10 and result in two edge sections 12. In the middle range it can Shrink profile can thus be approximated by a respective straight line 10. The two edge sections 12 are each separated by a circular segment 12 ' approximate and with a deflection and an edge offset value 14 and 16 respectively. Such an approximation is in the lower part of FIG shown for the left edge portion 12 of the shrink curve.

Around web tensions that run unevenly across the transverse direction To compensate, for example, a so-called spreader roller 18 (see FIG. 3) can be used. Such an arcuate, Originally cylindrical roller is currently used as a common used to generate an uneven web tension. there the paper 20 wraps around the spreader roller 18, in particular in obtuse angle.

If the bow of the spreader roller 18 preferably points in the direction of the tip thereof obtuse angle, so the web tension is in the middle of the paper web increased to the maximum as it falls towards the edges of the paper. Shows the arc in the direction of a leg of this angle or will achieved by swiveling the spreader roller that the paper 20th this spreader roller 18 only affects, the web tension distribution remains Paper web 20 largely unchanged. By swiveling the bow Any intermediate values can also exist between these two positions this train train influence can be achieved.

The following procedure is used in the present purely exemplary application conceivable: when printing paper with constant Shrinkage is used with no uneven expansion of the Paper. Consequently, the web tension in the Printing system must be evenly distributed across the paper running direction L. The Spreader roller 18 would then have to be adjusted so that it is as possible has no influence on the web tension.

For a roll of paper made with non-constant shrinkage to compensate for the uneven web tension during printing For example, the following procedure is conceivable: the spreader roller 18 is perpendicular to the paper running direction L on one side in the paper web 20 placed that thereby the described with reference to Figure 2 Edge offset 16 is compensated. Then the spreader roller pivoted so far that a corresponding immersion depth of the arch the deflection 14 described in Figure 2 is compensated. On In this way, a largely constant web tension over the paper web can be achieved 20 can be achieved.

LIST OF REFERENCE NUMBERS

10

Just

12

edge section

12 '

circular segment

14

deflection

16

margin shift

18

Spreader roll

20

Paper, paper web

L

Paper Grain

SP

shrinkage profile

Claims (28)

Process for the production and processing of paper (20),
characterized in that, in order to optimize at least one further processing process in paper production, information about the respective paper (20) determined is transmitted to the respective further processing process and taken into account in this. Method according to claim 1,
characterized in that the finishing process is a printing process. The method of claim 1 or 2,
characterized in that the further processing process is a formatting process, in particular a cutting process. Method according to one of the preceding claims,
characterized in that mechanical and / or technological properties ascertained in the paper production about the respective paper (20) are transmitted to the respective further processing process and are taken into account in this. Method according to one of the preceding claims,
characterized in that information about the respective paper (20), which is determined during the paper production, is transmitted to the respective further processing process and is taken into account in this. Method according to one of the preceding claims,
characterized in that information about the respective paper (20) ascertained in the paper production, information about at least one property and / or composition longitudinal profile is transmitted to the respective further processing process and taken into account in this. Method according to one of the preceding claims,
characterized in that information about the respective paper (20) ascertained during the paper production, information about at least one property and / or composition cross profile is transmitted to the respective further processing process and is taken into account in this. Method according to one of the preceding claims,
characterized in that information about the respective paper (20) ascertained during paper production transmits information about at least one longitudinal and at least one transverse profile of data relating to the paper web to the respective further processing process and is taken into account in this. Method according to one of the preceding claims,
characterized in that the information determined in the paper production is assigned to each roll after a roll cutting process by means of data carriers. Method according to one of the preceding claims,
characterized in that the further processing process is a printing process and that in order to optimize this printing process the shrinkage of the respective paper (20) which arises during paper production is also taken into account when printing. A method according to claim 10,
characterized in that position-related shrinkage values are taken into account. The method of claim 10 or 12,
characterized in that the transverse shrinkage (SP) is taken into account. Method according to one of the preceding claims,
characterized in that a shrinkage mean value resulting in the transverse direction and / or in the web running or longitudinal direction (L) is taken into account. Method according to one of the preceding claims,
characterized in that the fan-out is compensated on the basis of the average shrinkage. Method according to one of the preceding claims,
characterized in that the shrinkage is used to deduce the paper-specific expansion resulting when printing on the paper (20). Method according to one of the preceding claims,
characterized in that differences in paper web tension resulting in the transverse direction are compensated for by the shrinkage. Method according to one of the preceding claims,
characterized in that at least one data set comprising the relevant shrinkage values is assigned to each drum produced. A method according to claim 17,
characterized in that the data record comprises a sorting key assigned to the relevant drum. Method according to one of the preceding claims,
characterized in that transverse shrinkage values determined in the longitudinal direction at predeterminable intervals are taken into account. Method according to one of the preceding claims,
characterized in that , given the width of the paper (20) to be printed, an average value of the relevant shrinkage values in the longitudinal and / or transverse direction and / or the transverse shrinkage are taken into account. Method according to one of the preceding claims,
characterized in that a respective shrinkage curve (SP) is taken into account, which is approximated by a straight line (10) or a segment of a circle (12 ') and described with a deflection and an edge offset value (14 or 16). Method according to one of the preceding claims,
characterized in that at least one spreader roller (18) is used to compensate for web tensions which run unevenly in the transverse direction. Method according to one of the preceding claims,
characterized in that uneven paper expansion is compensated for by targeted moistening. The method of claim 23
characterized in that paper areas with smaller shrinkage values are moistened more than paper areas with larger shrinkage values. Method according to one of the preceding claims,
characterized in that , given the width of the paper to be printed (20), the paper shrinkage during paper manufacture is adjusted and / or regulated so that the shrinkage when viewed in the paper running direction (L) on one, for example the left, roll is linear to the Paper machine center decreases, is constant for the adjacent rolls and increases linearly for the roll provided on the other, for example the left, side. Method according to one of the preceding claims,
characterized in that the paper web (20) itself and / or a roll label assigned to the paper roll in question is provided with the shrinkage data. Method according to one of the preceding claims,
characterized in that the shrinkage data is stored on a separate data carrier. Method according to one of the preceding claims,
characterized in that the shrinkage data are transmitted to the print shop via a data network.

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