EP1543969B1 - Printing machine with at least one printing unit, screen rollers having groove - Google Patents

Abstract

Print machine has at least a printing unit with at least a waterless flat print forme (04) and a color deck with a printing ink conveying grid pattern roller (11), whereby the roller has linear grooves or hatching on its surface with an inclination or gradient angle of between 50 and 80 degrees.

Description

The invention relates to a printing machine with at least one printing unit according to the Preamble of claim 1.

By EP 1 044 110 B1 and belonging to the same patent family No. 6,439,116 B1 is an anilox roller of an inking unit of a rotary printing press known, wherein the lateral surface of the anilox roller endless or helical Creases (hashes) with an inclination angle or pitch angle in the range of 0 ° to plus / minus 20 °. The screen frequency is between 100 and 400 grooves per Centimeter.

By WO 03/045694 A1 and WO 03/045695 A1 methods are known in at those by tempering a cooperating with a rotating ink Component of a printing unit, a tack of the printing ink on the rotating component in a temperature range of 22 ° C to 50 ° C is kept substantially constant, wherein the tack of the ink on the temperature on the lateral surface of the rotating component and its production speed depends. The application consists in particular in a waterless printing unit, preferably in one Printing unit for newspaper printing.

WO 01/87036 A2 discloses a short inking unit of a rotary printing press, wherein in the inking unit an anilox roller pasty printing inks, in particular with a Viscosity greater than 9000 mPa * s, processing is arranged, with a grid of Anilox roller to a grid of a printing forme in the rotary printing machine arranged form cylinder in a ratio of 0.5, in particular greater than 0.8.

By the article "Waterless offset printing - alternative for economic, high-quality and Environmentally Friendly Print Production "in the journal Deutscher Drucker, No. 7 from 16.02.1995, pages W6, 8, 10, 12, it is known that in waterless offset printing Special, relatively tough inks are used, giving optimum print results by a tempering of inking rollers or by cooling the Form cylinder can be achieved, with a constant surface temperature of the Printing forms and the blankets is sought.

The invention is based on the object, a printing machine with at least one To create a printing unit that ensures a high quality of the printed products guaranteed in particular with regard to color brilliance. In the "dry offset" is a ensure sound-free printing.

The object is achieved by the features of claim 1.

The achievable with the present invention consist in particular that Properties of the printing ink used and ink-bearing parts of the printing press, in particular the anilox roller in a printing unit associated with their inking unit and the arranged on a form cylinder printing form, are coordinated with each other, that in a waterless printing process, especially in the "dry offset", a good Print result is achieved. Especially in newspaper printing can in this way Printing qualities are produced, which are the qualities of conventionally produced Print products, especially in the color brilliance, far exceed.

Fig. 1

eine schematische Darstellung einer für den Mehrfarbendruck geeigneten Druckmaschine mit vier Druckeinheiten jeweils mit zwei Druckwerken;

Fig. 2

eine schematische Darstellung eines Druckwerks mit einem Farbwerk;

Fig. 3

eine schematische Darstellung eines Formzylinders mit Druckformen;

Fig. 4

eine schematische Darstellung einer Rasterwalze mit einer Liniengravur oder Haschuren.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

Fig. 1

a schematic representation of a suitable for multi-color printing press with four printing units each with two printing units;

Fig. 2

a schematic representation of a printing unit with an inking unit;

Fig. 3

a schematic representation of a forme cylinder with printing plates;

Fig. 4

a schematic representation of an anilox roller with a line engraving or Haschuren.

Fig. 1 shows a greatly simplified form schematically a printing press 01, z. Legs Newspaper printing machine 01, preferably a plurality of different inks printing press, with in a frame 02 z. B. four vertically to each other arranged printing units, wherein a substrate 03, z. B. a web of material 03, in particular a paper web 03, in the vertical direction, the printing units in succession happens. A printing press 01 continuous production flow of the printing material 03 is assumed in this example essentially from the bottom up.

In the example shown in FIG. 1, in each printing unit on both sides of the Paper web 03 for the perfecting one printing unit each with a Ink transferring cylinder 06 and a transferring on the ink Cylinder 06 rolling form cylinder 07 is arranged. At least one of them Ink transferring cylinder 06 and a forme cylinder 07 existing Printing unit is associated with an inking unit 08, wherein each inking unit 08 at least one Ink supply 09 (Fig. 2), z. B. a paint box 09 or a color cartridge 09, and in Transport path of the ink from the ink supply 09 to the respective forme cylinder 07th one of the ink supply 09 ink receiving anilox roller 11 and at least one arranged between the anilox roller 11 and the forme cylinder 07 Inking roller 12 has. The inking unit 08 may comprise further rollers, for. B. at least one inking roller 13 and at least one distribution roller 14. In the in Fig. 1 a total of six rollers are grouped around the anilox roller 11, wherein two inking rollers 12 each on the anilox roller 11 and the forme cylinder 07th are employed, wherein along the circumference of the anilox roller 11 two ink rollers 13th are provided, wherein between each ink roller 13 and one of the inking rollers 12, a distributor roller 14 not in contact with the anilox roller 11 is arranged. Further details of the inking unit 08, in particular a doctor chamber 16 and a Doctor blade 16 with a preferably controllable drive 18 for employment at least a work squeegee to the lateral surface of the anilox roller 11, the Fig. 2 can be removed. The work squeegee is preferably in opposite directions to the lateral surface of the anilox roller 11th hired. Optionally, the doctor chamber 16 one of the working doctor in Circumferential direction of the anilox roller 11 spaced arranged squeegee. The Fig. 2 also shows a device 17 for supplying a printing forme 04 to the Form cylinder 07. The printing plate 04 can be largely automated on the lateral surface of the forme cylinder 07 are mounted.

The printing ink is coated with the at least one working doctor blade on the lateral surface of the Anilox roller 11 applied. The ink transferring cylinders 06 are preferably as a transfer cylinder operating in an offset printing 06 formed, wherein the transfer cylinder 06 preferably has an elastic surface have, wherein the elastic surface z. B. by at least one on the Lateral surface of the transfer cylinder 06 arranged printing blanket from a Elastomer material is formed.

In the exemplary illustration of FIG. 1, the two sides of the paper web 03 arranged transfer cylinder 06 in a so-called rubber-rubber arrangement employed against each other, so that the mutually employed transfer cylinder 06 mutually act as a counter-pressure cylinder. Alternatively, print works too a satellite printing unit are summarized, wherein the printing units to a common from the other cylinders 06; 07 separate impression cylinder are arranged, wherein the paper web 03 each between at least one of the Counter-pressure cylinder employed transfer cylinder 06 and the impression cylinder is guided.

Another alternative to the design of the printing machine 01 may provide that the Printing machine 01 z. B. as a commercial printing press with a preferably in Essentially horizontal guidance of the printing material 03 is formed, wherein in the Press 01 along the printing machine 01 continuous production flow of the printing material 03 preferably on both sides, d. H. below and above the Substrate 03, several successive printing units are provided, the Transfer cylinder 06 of two printing units in turn z. B. in a rubber-rubber arrangement are employed against each other, wherein the printing material 03 between the two mutually employed transfer cylinders 06 is passed, d. H. the substrate 03 passes through their mutual Abrollbereich. Alternative to Material web 03, the substrate 03 may be formed as a bow 03.

The transfer cylinders 06 associated with the form cylinder 07 have on their Lateral surface in each case at least one printing forme 04 (FIG. 2). Each printing plate 04 is in particular as one for a waterless planographic printing process ("dry offset") suitable planographic printing die 04 is formed, so that a supply of a dampening solution for the Training non-printing areas is not required. The forme cylinder 07 are in its axial direction X and / or in its circumferential direction Y preferably with several Printing forms 04 occupied (Fig. 3). In a newspaper printing press, the forme cylinders 07 in their axial direction X each z. B. with four or more printing plates 04 and in their Circumferential direction Y z. B. occupied with two printing plates 04, so then on each Form cylinder 07 eight or more printing plates 04 are arranged. In Fig. 3 is schematically a development of such a plate cylinder 07 with eight printing plates 04 shown, wherein the printing plates 04 are shown only half in the illustrated view and wherein belonging to the Fig. 3, perpendicular directional arrows X; Y to the forme cylinder 07 axial direction X and the circumferential direction Y of Show forme cylinder 07.

To generate a print image on the substrate 03, each printing forme 04 at least one print image on. Alternatively, it can be provided that the Printing plates 04 in the axial direction X to the forme cylinder 07 and / or in the circumferential direction Y of the forme cylinder 07 have multiple print image locations. Instead of on one Form cylinder 07 in its axial direction X z. B. four printing plates 04 and in the Circumferential direction Y z. B. provide two printing plates 04, the form cylinder 07 can each z. B. be occupied with only a single printing plate 04, this printing form 04 in for form cylinder 07 axial direction X z. B. four print image locations and / or in Circumferential direction Y of the forme cylinder 07 z. B. has two print image locations. Also can each printing form 04 each have only a single printed image point.

Preferably, the print on the same side of the printing material 03 in the Production flow of each other downstream printing units printing ink with each other different shades. For example, in each printing unit, color dots become one the colors used in four-color printing black, cyan, magenta and yellow prints. On the form cylinder 07 of the downstream printing units are with the same print image correlated print image locations, each a color separation of the form generating multicolor printed image, each color separation to one of associated with printing hues. A multicolored print image is created by that on the substrate 03 more color separations, z. B. the shades of black, Cyan, magenta and yellow respectively corresponding four color separations, one above the other are printed, with the color dots of the individual concerned the same printed image Separations on the substrate 03 next to each other or arranged one above the other be so that the multicolored print image by a color mixture of the different color separations resulting color dots. A color separation illustrative print image points for generating a common print image are of im Production flow of the printing material 03 arranged below each other Printing units with their respective from the form cylinder 07 ink transferring Cylinders 06 to print exactly on top of each other.

In waterless offset printing z. B. a silicone layer on the lateral surface of the Druckform 04 the role of the wettable hydrophilic area of the "Wet offset" to prevent the printing form 04 from taking a color. Becoming general the non-printing areas and the printing areas of the printing plate 04 through the Formation of areas of different surface tensions during interaction achieved with the ink. That's why in waterless offset printing Printing inks used, whose properties differ from printing inks, which in the conventional "wet offset" can be used.

To print sound-free, d. H. without ink acceptance on non-printing areas or even if they do, it is necessary to use a printing ink, which in its toughness (measured as Tack value) is set so that due to the surface tension difference between printing and non-printing areas on the printing plate 04 a flawless Separation can take place. Since the non-printing areas preferably as Silicone layer are formed, for this purpose, a printing ink with a compared to the "wet offset" much higher speed required.

According to the textbook "The web offset printing", Walenski 1995, the speed sets the Resistance, with the ink of the film cleavage in a nip or at the transfer of the ink in the print zone between the ink counteracts transferring cylinder 06 and the substrate 03. The speed of Printing inks, d. H. their tack value, z. B. according to the standard ISO 12634: 1996 (E) determined become. To determine the tack value are testing equipment, in particular as a Rolling system trained testing facilities, so-called "tackmeter", z. B. the Testing facilities "Inkomat" and "Tackomat" Fa. Prüfbau in D-82380 Peissenberg-Munich, to disposal. Tack values depend on the test equipment used and are given as dimensionless numerical values. Ink manufacturer give the tack value of an inks usually in conjunction with the zugunde set Test conditions, z. B. with which test device the tack value was determined and at which speed or surface speed of the measuring roller. typical Specifications refer to speeds of 400, 800 or 1200 revolutions per minute or on measurements with a surface speed of the measuring roller of about 100 Meters per minute to 300 meters per minute, especially 200 meters per minute. While In the test, the ink is heated to 32 ° C and at this temperature constant held. Printing inks show i. d. R. larger with increasing surface speed expectant tack values.

Since the speed of the ink changes with temperature, the operation of the Printing the form cylinder 07 and the inking unit 08 preferably cooled and / or kept at a constant temperature to change at Operating conditions during printing to avoid toning.

The tack of the ink influenced in addition to the separation of printing and non-printing areas, but also the strength of a plucking in the interaction of a color-leading transfer cylinder 06 with the substrate 03. Especially if the substrate 03 as uncoated, low-density newsprint with very good absorbency, ie open-pore and with very low impact time is carried out, increases the risk of loosening caused by fibers or dust. This danger is but z. B. also used in web offset printing lightly coated or lightweight, coated paper grades with a coating weight of z. B. up to 20 g / m ² , in particular between 5 and 10 g / m ² or even less before, wherein the line weight per unit area on a raw substrate, especially on a base paper, ie a paper without surface coating, applied coating weight. Overall, the temperature is particularly suitable for uncoated or coated papers with a coating weight of less than 20 g / m ² . For coated papers, the temperature control may be advantageous if it is determined that the line is "pulled off" (at least partially) from the paper by increasing tack.

To a chewing or building on the blanket and the printing plate 04 as low as possible The ink is tried for its intended purpose and the expected Operating conditions as close as possible to the lower limit of speed use.

With respect to the toning of the non-printing areas on the printing form 04 plays in addition to the speed of the ink, the relative speed at Detachment process, d. H. when splitting or loosening the ink, a crucial role. The printing ink is produced at a higher production speed v (FIG Surface or unwinding speed v of the printing cylinder 06 or the Conveying speed of the printing substrate 03, measured z. In m / s) in the gap both between the inking roller 12 and the printing plate 04 of the forme cylinder 07 as well between the printing plate 04 of the forme cylinder 07 and the blanket on the Transfer cylinder 06 larger demolition forces. The lower the relative speed, z. B. the intended production speed v is, the higher is the speed of the To choose ink to tone at lower production speeds v prevent. Otherwise, the wrong choice leads to poor print quality or during the startup operations to an increased volume of waste and a high Maintenance.

Increases the speed with increasing production speed v, so takes place i. d. R. a stronger plucking on the substrate 03 and increased building of Dirt and ink on the printing plate 04. This has complications and a increased maintenance frequency result, z. B. frequent washing of the surfaces, if the tack for a lower or middle range of production speed v was designed.

The tack value of printing inks used in waterless offset printing is z. In the Range between 2 and 16, aiming for a trouble-free printing, the Tack value to values z. B. between 6 and 9.5 to stabilize, in particular between 7 and 8.5. Ideally, the tack value is in the entire range of Production speed v from 1 m / s to 16 m / s and in the whole range of for the Printing process relevant temperature from 15 ° C to 50 ° C konstat. Because at one Reduction in tack occurs in the "tone range" increased toning, at magnification in In an area "plucking - building up" an increased plucking and reinforced building up the cylinders 06; 07 on. In practice, for the "dry offset" is a printing ink too use, which in the entire range for the production speed v of 1 m / s up to 16 m / s, in particular 3 m / s to 16 m / s, and / or in the entire range for the Temperature of 15 ° C to 50 ° C, in particular between 22 ° C and 40 ° C a tack value of 4 not less than 12. Ideally, the tack value is for the range of a production speed v of 3 m / s to 16 m / s or one Temperature of 22 ° C to 40 ° C in a range of 6 to 9.5, in particular between 7 and 8.5.

The viscosity of the ink is also decisive for the print quality Influencing factor. The viscosity of the ink is z. Eg according to the standard ISO 12644: 1996 (E) determined. Their value can be z. B. according to the above standard with a Bar viscometer or z. B. with the measuring method according to Höppler with a falling ball viscometer be determined. The viscosity is highly dependent on the temperature Measured variable. With increasing temperature show inks for the Printing process relevant temperature range between 15 ° C and 50 ° C, in particular between 22 ° C and 40 ° C, a significant drop in their viscosity. The value of the viscosity is below 350 for suitable printing inks in the temperature range between 22 ° C and 40 ° C Pa * s, in particular between 10 Pa * s and 150 Pa * s.

The lateral surface of the anilox roller 11 is suitable for transporting the printing ink Way to train. As indicated in FIG. 4, a line engraving or hash marks with an inclination angle or pitch angle α between 50 ° and 80 °, in particular between 50 ° and 60 °, on its outer surface of the anilox roller 11 advantageous. When Inclination angle or pitch angle α is considered to be the angle that the Line engraving or the Haschuren starting from a to the axis 19 of the anilox roller 11th form orthogonal planes 21 in a clockwise direction.

The anilox roller 11 has in its axial direction X a screen frequency z. B. from Less than 80 lines or Haschuren per centimeter, preferably less than 60 lines or Haschuren per centimeter, in particular between 30 and 35 lines or Hashes per centimeter. The body, z. B. the steel body of the anilox roller 11 is on the lateral surface z. B. with a ceramic, z. B. with chromium oxide coated, the radial layer thickness z. B. between 100 microns and 400 microns. In this coating are grooves or hashes with a depth between 20 microns and 200 microns z. B. by means Laser, z. B. with a CO2 laser introduced. The lines or Haschuren penetrate Accordingly, the coating does not, but remains at the bottom of the lines or Haschuren a layer thickness at least z. B. between 50 microns and 100 microns. The lines or Haschuren on the lateral surface of the anilox roller 11 are in the cross-sectional plane of the Fig. 2 - not to scale - by spaced wells on the circumference the anilox roller 11 indicated.

The printing plate 04 used, in particular planographic printing plate 04, is also connected to the Printing method and / or to the printing ink used. Also the printing form 04 has raster lines (not shown), wherein the raster lines have a raster frequency z. B. between 50 and 120 lines per centimeter. When using a low viscosity ink tends to print the 04 grid lines with a Grid frequency between 50 and 70 lines per centimeter, preferably 60 Lines per centimeter, whereas when using a more viscous Printing ink the grid lines with a screen frequency between 80 and 120 lines per Centimeters are formed. The raster frequency of the raster lines on the printing form 04 and the screen frequency of the lines or hashes on the anilox roller 11 are coordinated and can z. B. also at least approximately each other correspond.

At least the anilox roller 11 is preferably tempered. It is an advantage that To arrange printing plate 04 on a tempered forme cylinder 07. The anilox roller 11 and / or the forme cylinder 07 are preferably tempered from the inside, z. B. by a flowable tempering agent, for. As water, the anilox roller 11 and / or the Form cylinder 07 flows through the shell surface. With the temperature control is the Lateral surface of the anilox roller 11 in the temperature range z. B. between 22 ° C and 40 ° C. held and the lateral surface of the forme cylinder 07 in the temperature range z. B. between 20 ° C and 30 ° C.Die anilox roller 11 and / or the forme cylinder 07 have z. B. an axial Length of 500 mm to 1700 mm, in particular 1200 mm to 1300 mm.

LIST OF REFERENCE NUMBERS

01

press

02

frame

03

printing material; Web; Paper web; bow

04

Printing plate; Lithographic printing plate

05

-

06

Ink transferring cylinder; transfer cylinder

07

form cylinder

08

inking

09

-

10

-

11

anilox roller

12

Inking roller

13

ink roller

14

distributing roller

15

-

16

Blade chamber; blade beam

17

Device for feeding a printing forme to the forme cylinder

18

drive

19

axis

20

-

21

level

v

production speed

X

Directional arrow in the axial direction

Y

Directional arrow in the circumferential direction

α

Inclination angle; lead angle

Claims (26)

1. A printing press (01) with at least one printing couple and an inking unit (08) associated with the printing couple, wherein the inking unit (08) has an anilox roller (11) which conveys printing ink to the printing couple, wherein the generated face of the anilox roller (11) has grooves or hatchings with an angle of inclination or helix angle (α), wherein the angle of inclination or helix angle (α) is that angle which is formed by the grooves or the hatchings starting from a plane (21) at a right angle to the axis (19) of the anilox roller (11) in the clockwise direction, characterized in that the printing couple comprises at least one waterless flatbed printing forme (04), wherein the anilox roller (11) conveys, with grooves or hatchings having an angle of inclination or helix angle (α) of between 50° and 80°, printing ink suitable for the waterless flatbed printing forme (04).
2. A printing press (01) according to Claim 1, characterized in that the anilox roller (11 ) has a grid frequency of less than 80 grooves or hatchings per centimetre.
3. A printing press (01) according to Claim 2, characterized in that the anilox roller (11) has a grid frequency of less than 60 grooves or hatchings per centimetre.
4. A printing press (01) according to Claim 2, characterized in that the anilox roller (11) has a grid frequency of between 30 and 35 grooves or hatchings per centimetre.
5. A printing press (01) according to Claim 1, characterized in that the grooves or hatchings have an angle of inclination or helix angle (α) of between 50° and 60°.
6. A printing press (01) according to Claim 1, characterized in that the flatbed printing forme (04) has grid lines with a grid frequency of between 50 and 120 lines per centimetre.
7. A printing press (01) according to Claim 1, characterized in that the flatbed printing forme (04) has grid lines with a grid frequency of between 50 and 70 lines per centimetre.
8. A printing press (01) according to Claim 1, characterized in that the flatbed printing forme (04) has grid lines with a grid frequency of 60 lines per centimetre.
9. A printing press (01) according to Claim 1, characterized in that the flatbed printing forme (04) has grid lines with a grid frequency of between 80 and 120 lines per centimetre.
10. A printing press (01) according to Claim 1, characterized in that the flatbed printing forme (04) is arranged on a tempered forme cylinder (07).
11. A printing press (01) according to Claim 1, characterized in that the anilox roller (11) is tempered.
12. A printing press (01) according to Claim 10 or 11, characterized in that the forme cylinder (07) and/or the anilox roller (11) is or are tempered from the inside.
13. A printing press (01) according to Claim 10 or 11, characterized in that the forme cylinder (07) and/or the anilox roller (11) is or are tempered by a free-flowing tempering agent.
14. A printing press (01) according to Claim 3 or 6, characterized in that the grid frequency of the grid lines on the flatbed printing forme (04) and the grid frequency of the grooves or hatchings on the anilox roller (11) correspond to one another at least approximately.
15. A printing press (01) according to Claim 1, characterized in that in the temperature range of between 22°C and 40°C the printing ink has a viscosity of between 10 Pa*s and 150 Pa*s.
16. A printing press (01) according to Claim 1, characterized in that in the temperature range of between 22°C and 40°C the printing ink has a tack value of between 6 and 9·5.
17. A printing press (01) according to Claim 1, characterized in that in the temperature range of between 22°C and 40°C the printing ink has a tack value of between 7 and 8·5.
18. A printing press (01) according to Claim 1, characterized in that for a production speed (v) of the printing press (01) of from 3 m/s to 16 m/s the printing ink has a tack value of between 4 and 12.
19. A printing press (01) according to Claim 1, characterized in that in the temperature range of between 22°C and 40°C and for a production speed (v) of the printing press (01) of from 3 m/s to 16 m/s the printing ink has a tack value which is substantially constant.
20. A printing press (01) according to Claim 1, characterized in that a cylinder (06) of the printing couple, which transfers printing ink, applies printing ink to a material to be printed (03) with a coating weight of up to 20 g/m².
21. A printing press (01) according to Claim 1, characterized in that a cylinder (06) of the printing couple, which transfers printing ink, applies printing ink to the material to be printed (03) with a coating weight of between 5 g/m² and 10 g/m².
22. A printing press (01) according to Claim 1, characterized in that the material to be printed (03) is in the form of a web of material (03) or in the form of a sheet (03).
23. A printing press (01) according to Claim 1, characterized in that the printing couple applies printing ink to the material to be printed (03) in a waterless flatbed printing process.
24. A printing press (01) according to Claim 1, characterized in that the printing press (01) is designed in the form of a newspaper printing press.
25. A printing press (01) according to Claim 1, characterized in that the printing press (01) is designed in the form of a jobbing machine.
26. A printing press (01) according to Claim 1, characterized in that the printing press (01) prints in multicolour printing.

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