EP1050622A2 - Application device and process for a papermaking machine - Google Patents

Abstract

The papermaking machine has a station to spray the fiber web with water and/or a bonding agent, with jets distributed across machine width in at least one row. The bonding agent is sprayed on to the web surface at the drying section of the papermaking machine The row of jets have structured openings, to apply a closed film of bonding agent over the web surface. The jet openings gi spray stream with a droplet size of 20-250 mu m and pref. 50-70 mu m. A system controls the longitudinal profile and/or the mass the applied bonding agent on the web surface from the row of jets, using a monitor to register the mass/longitudinal and or mass/lateral profile, coupled to a control circuit. The bonding agent is applied to the web surface, by the jets, at a rate of 0.05-5.0 g/m<2> dry rate with a bonding agent solution concentration of 2-30 wt% and pref. 5-20 wt% and especially 10-15 wt%, working with a machine speed of 8-50 m/sec. and pref. 10-35 m/sec. The application jets have an average throughput of the bondin agent solution of 0.03-5.0 l/min. and pref. 0.05-3.0 l/min. and especially 0.06-1.0 l/min. The jets, across the machine width, a at intervals of 10-100 mm and pref. 20-70 mm and especially 25-50 mm. The system uses at least two rows of jets, with pref. one for the jets which deliver the bonding agent. The application system with the web drying station (3) gives the paper a dry conte of ≥ 55% and pref. ≥ 60% and especially ≥ 80%. At the calender (4), to polish the web, the dry content is ≥ 90%. An Independent claim is included for a papermaking machine with at least one jet applicator system at the drying station (3) and/or calender (4). With a paper for gravure printing, the jet sprays are wholly to equalize the lateral moisture content profile of t paper. If the paper is for offset printing, a bonding agent pref. of starch is used additionally or wholly to treat the web surf Preferred Features: The spray jets are located on both sides of the paper web. At least one jet applicator is at a gap of 10-200 from the web and pref. 20-250 mm and especially 20-100 mm. The applied bonding agent also affects the lateral moisture content profile of the web.

Description

The invention relates to an application device, in particular a nozzle moistener for a paper machine a variety of machine-wide distributed nozzles for Spraying a passing paper web. Farther The invention relates to a paper machine for production of gravure and offset paper, with at least one Dryer section and a smoothing unit. In addition, the Invention the use of a nozzle moistener Improving the paper properties of an offset paper. Finally, the invention also relates to a method for Improving the surface of a paper for use as Offset printing paper.

Different printing processes are different Demands on the quality and properties of the produced Paper in order to achieve optimal print quality. For example, high-quality prints are printed in the Gravure printing or offset printing processes.

In gravure printing, the printing ink is on the paper applied by first applying the paint in the wells a printing plate is stored, then when the Pressure plate over the passing paper from the paper to be taken over.

In contrast, this is the case with the offset printing process Print image on a surface (hydrophilic / hydrophobic) projected, whereby the Change surface properties. Take hydrophobic spots the positive ink on while hydrophilic spots Absorb water.

Because of the very different techniques of printing will also have different quality requirements and the properties of the paper to be printed posed. For example, a special for Gravure-suitable paper with a very high proportion of Fillers are enriched to the Optimally adjust surface properties in the satin process to be able to. It is also very good with offset printing essential that the paper used is high Has surface strength, as little dust and has little tendency to pick to get the desired achieve high print quality and good printability can.

According to these requirements are mostly Paper machines manufactured and operated, which specifically for the production of one or the other type of Paper. However, it faces the same problems Equip paper machine so that it is ready for manufacture for both variants of the paper - i.e. gravure paper and Offset printing paper - well suited without having to change types having to make too large changes.

It is from German published patent application DE 196 32 637 A1 known to try to produce a high quality Printing paper for the offset printing process an aid to increase the strength in the z direction of the paper (= perpendicular to the paper surface) or the Surface strength added to the mass. The disadvantage this measure is the rather low one Efficiency of adding auxiliaries to the bulk of the Papermaking. That said, it's a disproportionate high amount of auxiliaries (binders) necessary in the mass, to achieve a sufficient effect on the surface.

off line" mit Hilfe geeigneter Auftragsaggregate bestrichen wird und daß dadurch eine hohe Oberflächengüte erzielt wird, die sich für den Offset-Druck eignet.In addition, it is generally known that the surface of a finished paper web is subsequent to its manufacturing process

is coated off line "with the aid of suitable application units and that a high surface quality is achieved which is suitable for offset printing.

The disadvantage of this known method is that for additional application units, possibly for a separate system for off-line "order, high production and investment costs are necessary and these thus drive up the production costs of such paper.

Furthermore, nozzle dampers are known in the prior art, with which water is sprayed onto a finished paper web, a desired, as even as possible around the paper web To give moisture profile. After this treatment the Paper web mostly passed through calenders, creating a as even and particularly smooth a surface as possible is achieved. Regarding the nozzle humidifier is on the References EP 0 345 670 B1 and DE 38 19 761 C2. On Calender or smoothing unit is from the German, for example Publication DE 195 42 191 A1 known.

It is an object of the invention to provide a way describe with which a single paper machine is optional and without lengthy adjustments for both the manufacture a gravure paper (SC paper), as well as for the Production of offset paper is equally suitable.

This task is characterized by the characteristics of each independent claims solved.

According to the inventive concept, it is proposed Paper machine for the production of rotogravure and offset paper with at least one dryer section and a smoothing unit to develop further in the area of Drying section at least one nozzle moistener is provided, that in the case of the production of gravure paper exclusively to even out the moisture cross profile the paper web is used and in the case of the manufacture of Offset paper only for the application of a Binder - preferably starch - is used.

By using the nozzle humidifier in the Drying section of the paper machine for the application of Binder becomes possible for the first time on one and the same Paper machine without making any special changes must, both gravure paper and high quality offset printing paper to manufacture.

If the paper is suitable for offset printing on both sides should, the at least one nozzle moistener on both Sides of the paper web are provided.

When attaching the nozzle moistener, or one with Other applicator, it is for Avoiding excessive fog formation is beneficial to one Distance of 10 to 200 mm, preferably 20 to 150 mm, preferably 20 to 100 mm, between the Nozzle exit points of the nozzle moistener and the paper web to adhere to.

According to the invention, an application device, especially a nozzle moistener, for a paper machine a variety of machine-wide distributed nozzles for Spraying the passing paper web, suggested, at the at least one row with nozzles for the throughput of Water and / or a binder solution can be provided can.

This configuration makes it possible to focus on the special properties of binder solutions adjust so that the nozzles correspond to the different consistency, toughness and that Volume throughput can be adjusted.

It can also be advantageous here if at least one Row of nozzles that penetrate the binder with Nozzle openings is provided that a closed Create binder film on the passing web.

It can also depend on the binder used also be cheap, at least one row of nozzles with openings to provide a spray with a Droplet size 20 to 250 µm, preferably 50 to 70 µm, form.

Another advantageous embodiment of the invention Application device provides that for at least one Row of nozzles that penetrate the binder, medium can be used, the longitudinal profile and / or Cross profile of the applied mass of binder over the Regulate or control machine width. This will make it possible, either for a constant application layer to worry about in the manufacturing process, or even the cross section regulate or control the layer thickness via the web.

Alternatively, there is also the option of using the Adjustment of the layer thickness of the application to binder, Non-uniformities in the previous paper thickness over one certain length and / or at a certain section of the Compensate paper web and in this way a total uniform mass transverse profile and / or longitudinal mass profile of the To reach paper web.

The means for regulating the control of the mass cross-section and / or the mass longitudinal profile of the applied binder can, for example, a variety of volume flow influencing valves, with each valve one Nozzle or a group of nozzles of the application device assigned.

However, there is also the possibility that Mass cross profile and / or the longitudinal mass profile of the applied binder by influencing that Concentration of the applied binder over the Machine width according to the requirements of one more or to regulate less intensive application of binders or to control.

For the establishment of a control loop, which the Adjust the mass profile of the applied binder , at least one measuring device for the Longitudinal profile after the application device be provided so that a control loop coupled thereto can arise.

Should be the mass cross profile of the applied binder are regulated, so is a measuring device for the Mass cross profile necessary, for example can consist of a single measuring head over the Machine width is moved. Likewise, a variety of Measuring heads are used, which are fixed only one measure certain section or only over a certain one Area are movable in the cross machine direction and over move this area.

The application devices are also advantageously designed in such a way that the nozzles are designed for an average binder solution throughput which is based on an area application of 0.05 to 5 gr / m ^{2 of} otro binder at a concentration of the binder solution of 2 to 30% by weight, preferably 5 up to 20% by weight, preferably 10 to 15% by weight, binder and a machine speed of 8 m / s to 50 m / s, preferably 10 m / s to 35 m / s. Furthermore, the nozzles of the application device should have an average binder solution throughput of 0.03 l / min to 5 l / min, preferably 0.05 l / min to 3 l / min, preferably 0.06 l / min to 1 l / min , be designed.

Regarding the controllability of the application device, it is advantageous, the nozzle of the nozzle moistener Zone width - this is the distance from nozzle to nozzle in one machine-wide range - from 10 to 100 mm, preferably 20 up to 70 mm, preferably 25 to 50 mm.

For a particularly even application of the binder on the paper web, it is also advantageous if at least two rows, preferably one row for the Application of the binder are available.

In accordance with the inventive concept, it is also proposed known nozzle humidifier to improve the To use paper properties of an offset printing paper, and binders on the passing web in the area of Apply dryer section. It is particularly cheap of course if the nozzle moistener is at least one of the previously mentioned features of a nozzle moistener according to the invention having.

Furthermore, a method for surface improvement of an offset paper proposed, which is thereby distinguishes that machine-wide binders in the range of Drying section of a paper machine on the in Manufacturing process located paper web is applied.

It is particularly advantageous here if the application of the Can be done with the help of a nozzle moistener, it being especially for the application of the binder is favorable if the application of the binder by a spray with a droplet size of 20 to 250 µm, preferably 50 to 70 microns. Alternatively or in There is also the possibility of applying the combination Binder, especially the nozzles of the Application device to design such that the Binder as a closed film on the paper web is applied.

Another advantageous embodiment of the invention The method provides that the longitudinal profile and / or transverse profile the mass of binder applied over the Machine width is regulated or controlled. This regulation can be designed such that the masses of the applied binder by a section Change in concentration of the applied binder solution takes place. This has the advantage that the amount of only a small amount of solvent to be evaporated Result in changes. However, there is also Possibility of just spraying the amount To regulate binder solution. This can be done in sections or across the entire machine width.

Advantageous values for the area application of the binder are in the range of an average area loading of the paper from 0.05 to 5 gr / m ^{2 of} otro binder, a concentration of the binder solution of 2 to 30% by weight, preferably 15 to 20% by weight, preferably 10 to 15% by weight, can be used advantageously.

Furthermore, there are favorable operating values when the nozzles the nozzle humidifier on average 0.03 l / min to 5 l / min, preferably 0.05 l / min to 3 l / min, preferably 0.06 l / min up to 1 l / min, enforce binder solution.

As mentioned above, instead of just one Side of the paper web also with both sides of the paper web at least one nozzle moistener coated with binder become.

For an optimal connection between the applied Binder and the paper web should be the paper web one Dryness greater than 55%, preferably greater than 60%, preferably greater than 80%, if the binder is applied.

It can also be advantageous if with the Binder application also the moisture cross profile of the paper web is influenced in the desired direction. Appropriate Regulation and control mechanisms are, for example, from the German patent DE 38 19 761 C2 known.

It is understood that the above and Features of the invention not yet to be explained below only in the specified combination, but also in other combinations or used alone, without leaving the scope of the invention.

Additional features and advantages of the invention result more preferred from the following description Embodiments with reference to the drawings.

Figur 1:

Übersicht einer Papiermaschine

Figur 2:

Trockenpartie mit Düsenfeuchter

The invention will be explained in more detail below with reference to the drawings. They represent:

Figure 1:

Overview of a paper machine

Figure 2:

Dryer section with nozzle moistener

Figure 1 shows the overview of an inventive Paper machine with a sheet forming unit 1, which here as Twin wire former is formed. Then there is one Press section 2 with two press shoes, one of which Dryer section 3 connects, in which according to the invention - here not shown - nozzle dampers are housed. Then the smoothing 4 follows in the likewise Nozzle can be provided and the reel 5 in which the finished paper web is rolled up.

The drying section 3 is again more detailed in FIG. 2 shown. It is a single row Dryer section with two in a manner known per se Nozzle dampers 6 and 7 are equipped, which in this Image only arranged on one side of the paper web are.

The percentages above the dryer section shown represent the dryness of the through the dryer section continuous paper at the respective position. According to the invention there is the possibility itself known nozzle dampers for applying a binder use. You can also use additional nozzle dampers be attached, which is also the second side of the Provide drying paper web with binder.

Reference list

1

Sheet formation unit

2nd

Press section

3rd

Dryer section

4th

Smoothing unit

5

Reeling

6.7

Nozzle moistener

Claims (30)

Application device, in particular nozzle moistener, for a paper machine with a variety of machine-wide distributed nozzles for spraying a passing paper web, with at least one row of nozzles for the throughput of water and / or Binder is provided. Application device according to the preceding claim 2, characterized in that at least one row of nozzles which penetrates the binder is provided with nozzle openings which produce a closed binder film on the paper web passing by. Application device according to one of the preceding claims 1-2, characterized in that at least one row of nozzles which penetrates the binder is provided with nozzle openings which form a spray jet with a droplet size of 20-250 µm, preferably 50-70 µm. Application device according to one of the preceding claims 1-3, characterized in that means are provided for at least one row of nozzles which penetrate the binder, which regulate or control the longitudinal profile and / or the transverse profile of the applied mass of binder over the machine width. Application device according to one of the preceding claims 1-4, characterized in that the means for regulating or controlling the mass transverse profile and / or the longitudinal mass profile of the applied binder contain a plurality of valves which can be influenced throughput, each valve being assigned a nozzle or a group of nozzles of the application device is. Application device according to the preceding claim 5, characterized in that the means for regulating the longitudinal mass profile of the applied binder comprise a measuring device for the longitudinal mass profile and a control loop coupled thereto. Application device according to one of the preceding claims 5-6, characterized in that the means for regulating the transverse mass profile of the applied binder comprise a measuring device for the transverse mass profile and a control loop coupled thereto. Application device according to one of the preceding claims 1-7, characterized in that the nozzles of the application device are designed for an average binder solution throughput which has an area application of 0.05 to 5 g / m ² otro binder at a concentration of the binder solution of 2%. up to 30% by weight, preferably 5% to 20% by weight, preferably 10% to 15% by weight of binder and a machine speed of 8 m / s to 50 m / s, preferably 10 m / s to 35 m / s. Application device according to one of the preceding claims 1-8, characterized in that the nozzles of the application device have an average binder solution throughput of 0.03 l / min to 5 l / min, preferably 0.05 l / min to 3 l / min, are preferably designed from 0.06 l / min to 1 l / min. Application device according to one of the preceding claims 1-9, characterized in that the nozzles of the application device have a zone width (= distance from nozzle to nozzle in a machine-wide row) from 10 mm to 100 mm, preferably 20 mm to 70 mm, preferably 25 mm to 50 mm. Application device according to one of the preceding claims 1-10, characterized in that at least two rows, preferably one row, are provided for the nozzles applying the binder. Application device according to one of the preceding claims 1-11, characterized in that it is arranged in the drying section (3) in the region of a dry content of the paper web of greater than 55%, preferably greater than 60%, preferably greater than 80%. Application device according to one of the preceding claims 1-11, characterized in that it is arranged in the smoothing unit (4) in the region of a dry matter content of greater than 90%. Paper machine for the production of gravure and offset paper, at least with a dryer section and a smoothing unit, characterized in that at least one application device (6, 7) is provided in the region of the dryer section (3) and / or the smoothing unit (4) in the case of the production of rotogravure paper it is used exclusively as a means for equalizing the moisture cross profile of the paper web, and in the case of the production of offset paper it is used additionally or exclusively for the application of a binder, preferably starch. Paper machine according to the preceding claim 14, characterized in that at least one application device (6, 7) is provided on both sides of the paper web. Paper machine according to one of the preceding claims 14-15, characterized in that the at least one application device (6, 7) is at a distance of 10 mm to 200 mm, preferably 20 mm to 150 mm, preferably 20 mm to 100 mm from the paper web. Paper machine according to one of the preceding claims 14-16, characterized in that the at least one application device (6, 7) has the features of one of claims 1 to 11. Use a nozzle moistener (6,7) for improvement the paper properties of an offset paper Applying a binder to a passing one Paper web. Use of a nozzle moistener (6, 7) according to the preceding claim 18, characterized in that it has the features of one of claims 1 to 13. Process for improving the surface of an offset paper, characterized in that machine-wide binder is applied in the area of a dryer section of a paper machine to the paper web being manufactured. Method according to the preceding claim 20, characterized in that the binding agent is applied with the aid of a nozzle moistener (6, 7). Process according to the preceding claim 21, characterized in that the binder is applied by at least one spray jet with a droplet size of 20-250 µm, preferably 50-70 µm. Method according to one of the preceding claims 20-22, characterized in that the longitudinal profile and / or the transverse profile of the mass of binder applied is regulated or controlled over the machine width. Method according to the preceding claim 23, characterized in that the regulation or control of the mass transverse profile and / or the longitudinal mass profile of the applied binder takes place by changing the concentration of the applied binder solution in sections. Method according to one of the preceding claims 20-24, characterized in that a surface application of the binder with an average surface loading of the paper of 0.05 to 5 g / m ^{2 of} otro binder at a concentration of the binder solution of 2% to 30% by weight, preferably 5% to 20% by weight, preferably 10% to 15% by weight, binder. Method according to one of the preceding claims 20-25, characterized in that the nozzles of the application device (6,7) on average 0.03 l / min to 5 l / min, preferably 0.05 l / min to 3 l / min, preferably push through 0.06 l / min to 1 l / min binder solution. Method according to one of the preceding claims 20-26, characterized in that the paper web is coated on both sides with at least one application device (6, 7) with binder. Method according to one of the preceding claims 20-27, characterized in that the application of the binder in the dryer section (4) takes place with a dry content of the paper web of greater than 55%, preferably greater than 60%, preferably greater than 80%. Method according to one of the preceding claims 20-28, characterized in that the application of the binder in the smoothing unit 4 takes place at a dry content of greater than 90%. Method according to one of the preceding claims 20-29, characterized in that the moisture cross profile of the paper web is also influenced with the application of the binder.

Images