DE102017001946A1

DE102017001946A1 - Web tension decoupling device

Info

Publication number: DE102017001946A1
Application number: DE102017001946.0A
Authority: DE
Inventors: Felix Titz
Original assignee: RSD - Industrietechnik GmbH; Rsd Ind GmbH
Current assignee: RSD - Industrietechnik GmbH; Rsd Ind GmbH
Priority date: 2017-02-28
Filing date: 2017-02-28
Publication date: 2018-08-30

Abstract

Plant for the production of corrugated cardboard with an integrated digital printing unit 9 for printing smooth paper webs 2, characterized in that the web tension of the paper web is decoupled in the digital printing unit of the web tension of the paper web in the corrugator.

Description

From the EP 0 387 552 B1 is a corrugator known for the production of corrugated board.
From the DE 103 12 601 A1 is a digital printing device in a corrugator known.
In order to achieve high print quality, it is necessary to print on the smooth web. This digital printing device is preferably used between the paper web dispenser and a preheater. The preferred installation location is after the Kaschierbahnabroller 21st 1 ,
Another in the DE 103 12 601 A1 8th mentioned location is between the cover sheet dispenser 2 and the single-sided machine. 1
From the DE 10 2014 013 370 A1 It is known that, among other things, the web tension of the digitally printed web is of great importance in order to achieve high print quality.
task
For the production process of corrugated cardboard web tension is required so that the paper webs is intimately connected to the preheater and thus can absorb the necessary temperature and also a straight flat sheet can be produced. This web tension is applied between the dispenser and the heating section by means of brakes attached to the dispenser. A web tension control is from the DE 43 12 534 A1 known, but which does not produce the required accuracy. As is known, web tension fluctuations of up to 300% occur in the production process of corrugated board. As a result, the position of the web to be printed on the successively arranged printing devices of the printing unit no longer match. Thus, a high print quality is no longer given what leads to rejects.
Constant web tension influencing variables can once with the in the DE 100 2014 013 370 A1 be compensated in advance, or with the in DE 103 12 601 A1 mentioned measuring devices are subsequently corrected. However, this creates rejects, since the control of the printed image of the printing unit is locally downstream due to production.
Web tension fluctuations occur e.g. through non-circular paper rolls.
When Splice, connecting an empty role with a full role, occur web tension fluctuations.
Web tension fluctuations occur by accelerating or decelerating the corrugator.
Web tension variation occurs by stretching and contraction from the heated bed belt.
As a result of these web tension fluctuations, which inevitably occur in the process for the production of corrugated cardboard, an enormous amount of waste occurs in the digital printing of a paper web, since these fluctuations can not be compensated, since they occur repeatedly for a short time.
The object of the invention has been found to integrate a digital printing device in a corrugated board so that web tension fluctuations that inevitably occur in the process of producing corrugated board, have no effect on the print quality.
This is achieved by the fact that before and after the digital printing device, a device is used which decouples the web tension between the corrugator and the printing device.
Several embodiments of the invention are explained below with reference to the drawing. In this show:
list of figures

1 a schematic representation of a unwinder with a splicer, not shown, the first web tension decoupling device, the digital printing unit, a second web tension decoupling device and a preheater. For the description of the other components of the corrugated cardboard plant is on the DE 103 12 601 A1 directed.
2 a second embodiment of the invention. Components that correspond to those already referring to the 1 have been described bear the same reference numerals and will not be explained again in detail.

The following is with reference to the 1 a first embodiment of the invention described. The 1 schematically shows a dispenser 1 on which the paper web 2 is rolled off. The paper web is then glued later with the unilateral web, not shown. The paper web is via the splicer, not shown 3 to a towing device 4 guided. This drawbar consists of a driven pair of rollers and pulls the web from the dispenser 1 from. The drawbar 4 can also consist of a driven vacuum belt. After that, the paper web 2 in a slack 5 placed. Downstream then followed by a driven brake roller pair 6 , This brake roller pair 6 can also be from one of the paper web 2 wrapped driven brake roller or turn consist of a driven vacuum brake band. The slack 5 is by means of a distance sensor 7 measured and thus the drive from the drawbar 4 controlled. Thus, the paper web 2 in the slack 5 bahnspannungslos. Further downstream is the paper web 2 via a guide roller 8th into the digital printing unit 9 initiated. By means of the print heads shown schematically 10 becomes the paper web 2 digitally printed. The paper web is over deflection rollers 11 and 12 fed to the second web tension decoupling device. This consists of a driven Zugwalzenpaar 13 which the paper web 2 through the digital printing unit 9 pulls with constant web tension. This Zugwalzenpaar 13 can also consist of a driven vacuum belt. After that, the paper web 2 in a slack 14 placed. Downstream followed by a driven brake roller pair 15 , which is the tension in the paper web necessary for the production process for the production of corrugated board 2 provides. This driven pair of brake rollers 15 may in turn consist of a single looped driven brake roller or from a driven brake vacuum belt. To detect the sag, a distance sensor 16 used, which detects the slack and the drive from the Zugwalzenpaar 13 regulates. Thus, the paper web 2 is sagging 14 bahnspannungslos. After the pair of brake rollers 15, the paper web with the web tension necessary for the production process becomes the preheater 18 fed over deflection roller 17. This web tension decoupling device, consisting essentially of the Zugwalzenpaar 4 , the slack 5 , the brake roller pair 6 , the distance sensor 7 , the Zugwalzenpaar 13 , the slack 14 , the brake roller pair 15 and the distance sensor 16 can also be like in DE 103 12 601 A1 in 8th illustrated printing unit 4 between the dispenser 2 and the one-sided machine 1 be used.
In the web tension decoupling device in 2 will replace the slack 5 and the slack 14 loops 19 and loops 20 generated. To control the loops 19 and the loops 20 become the sensors 7 and 16 used, which drives the pull rollers 4 and 13 Taxes. Instead of the sensors 7 and 16 can also be a path measurement of the paper web 2 between Zugwalzenpaar 4 respectively. 13 and brake roller pair 6 respectively. 15 from which then the loops are calculated so that there are always loops. By this loop formation, a decoupling of the web tension in the printing unit is given by the web tension of the corrugator.
QUOTES INCLUDE IN THE DESCRIPTION
This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.
Cited patent literature

EP 0387552 B1 [0001]
DE 10312601 A1 [0002, 0004, 0007, 0015, 0016]
DE 102014013370 A1 [0005]
DE 4312534 A1 [0006]
DE 1002014013370 A1 [0007]

Claims

Plant for the production of corrugated cardboard with an integrated digital printing unit 9 for printing smooth paper webs 2, characterized in that the web tension of the paper web is decoupled in the digital printing unit of the web tension of the paper web in the corrugator.
Plant for the production of corrugated cardboard Claim 1 , characterized in that only the voltage of the incoming into the digital printing unit 9 web is decoupled.
Plant after Claim 1 , characterized in that only the voltage of the expiring from the digital printing unit web is decoupled.
Installation according to one of the preceding claims, characterized in that the web tension decoupling takes place by means of sag 5 or 14.
Installation according to one of the preceding claims, characterized in that the web tension decoupling takes place by means of loops 19 and 20, respectively.
Process for the production of digitally printed paper webs in a corrugated cardboard plant With at least one unwinding device 1 for unrolling the paper web 2 - With a pulling device 4, which pulls the paper from the paper roll - With a web tension-free area 5 or 19 - With a braking device 6, which applies the necessary for printing web tension - With a digital printing device 9, which applies the print image on the paper web 2 by means of print heads 10 - With a traction device 13, which promotes the paper web 2 through the printing unit - With a trackless space 14 and 20 respectively - With a braking device 15, which applies the web tension required for corrugated board production.