Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F13/00—Common details of rotary presses or machines
  • B41F13/004—Electric or hydraulic features of drives
  • B41F13/0045—Electric driving devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F13/00—Common details of rotary presses or machines
  • B41F13/02—Conveying or guiding webs through presses or machines
  • B41F13/025—Registering devices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F5/00—Rotary letterpress machines
  • B41F5/24—Rotary letterpress machines for flexographic printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41P—INDEXING SCHEME RELATING TO PRINTING, LINING MACHINES, TYPEWRITERS, AND TO STAMPS
  • B41P2213/00—Arrangements for actuating or driving printing presses; Auxiliary devices or processes
  • B41P2213/90—Register control

Definitions

• the invention relates to a method for correcting the longitudinal register error according to the preamble of claim 1.
• Printing multicolored printed images with rotary printing presses usually takes place in that the printing material passes through different inking units in succession, each of which applies one color to the printing material, so that the resulting multicolored printed image is created as a layering of several printed images.
• the accuracy with which this layering is carried out is of great importance for the quality of the printed image.
• Displacements of the different print images against each other in the printing direction are called longitudinal register errors.
• the deviations referred to as longitudinal registers or circumferential registers are generally corrected by the machine operator at the beginning of the printing process by the machine operator checking the relative position of so-called register marks which are applied by the various printing units.
• this method has the disadvantage of a long reaction time and the associated large rejects.
• DE 195 27 199 therefore suggests registering the register marks with detection sensors during the entire printing process, feeding the measurement results from the sensors to a control and computing unit and performing the longitudinal register correction by at least a short printing cylinder Period with a different peripheral speed than that
• this process requires permanent optical monitoring of the printed image.
• the object of the invention is therefore to propose a method which does not require constant monitoring.
• the invention is based on the finding that both in the pressing and in the operation of rotary printing machines there is a need to adjust the position of the rollers involved in the printing process to one another. In specialist circles, this position setting is called the side-by-side process.
• printing presses have suitable bearings for the rollers involved in the printing process.
• a flexographic printing machine is known from DE 40 01 735 A 1, in which the carriages carrying the printing roller and the carriages carrying the inking or anilox rollers are guided in a common carriage guide of the inking unit consoles of the printing press and can be moved jointly or individually by spindle drives.
• the setting of the printed image is normally carried out as follows.
• An electronic control device is provided which can access data entered in a storage device.
• the data relate to the travel between the pressure and the counter pressure roller, taking into account the geometric dimensions of the machine and the diameter of the rollers.
• This control device then sets the relative roller positions, so that it should be ensured that all parts of the printed image are transferred.
• the clichés of these rollers are pressed in on the pressure line between the cliché and counter-pressure rollers. At high circular speeds, the roller no longer reaches its actual radius measured before the printing process, since the return speed of the flexible plate material is not sufficient.
• an effective longitudinal register correction can be carried out without the control device being constantly subjected to evaluation and arithmetic operations, as in the method according to DE 40 01 735 A.
• the known control devices are the parameters necessary for carrying out the method such as the current relative position of the rollers of the individual printing units is known, so that the method can also be carried out completely without additional measuring devices, such as expensive optical sensors.
• the method according to the invention can be combined with other known methods. It is thus possible to check the correctness of the register with optical sensors during pre-registration or at certain time intervals and to correct it accordingly.
• the use of the method according to the invention eliminates the need to constantly carry out measurement and calculation processes. Further exemplary embodiments of the invention are explained in more detail in the present description. The figures show:
• 9 1 schematically shows a flexographic printing machine with a plurality of
• Fig. 2 schematically shows a plate roller in the printing process
• FIG. 1 schematically shows the arrangement of inking units 1 to 8 of a flexographic printing machine 10 around the impression cylinder 11, only the inking units 1, 4 and 8 being shown completely.
• the inking units are suspended from a machine frame, not shown.
• the inking unit n (n denotes any of the existing inking units) comprises a plate roller K n and an inking roller F n .
• the axes of rotation of the plate rollers are denoted by M n and those of the impression cylinder by Mn.
• the straight lines, which are defined by the axes of rotation Mn and D n are denoted by S n .
• D n is the pressure line of the plate roller K n on the impression cylinder. Between the straight line S n and the axes of the squeezing BA n arise angle ⁇ n.
• the effective pressure line between the plate rollers K n and the impression cylinder 11 are denoted by D n .
• the inking units 1, 4 and 8 show, by way of example, different possibilities for aligning the inking units or the axes of the auxiliary movements BA to the straight line S n , while the other printing units are merely outlined.
• the side axis BAi thus runs on the straight line Si, so that there is no shifting of the pressure line Di when it is provided.
• Such an arrangement would be called a strictly radiation-like arrangement of the inking units.
• An approximately radiating arrangement is shown using inking unit 8.
• the axis of the supply BA 8 does not run on the beam Ss and the angle (Xs between the supply axis BA 8 and the beam Ss is created.
• Each additional movement of the roller Ks leads to a shift in the effective pressure line D 8 on the circumference of the rollers 11 involved and Ks.
• Figure 2 shows the position of the plate cylinder Kg during the printing process using the example of the plate roller Kg.
• the plate cylinder Kg and other flexible materials involved in the printing process such as the rubber lining of the counter-pressure roller (not shown) and the printing material (also not shown) are exposed to strong forces in the printing process.
• the cliché 12 is squeezed along the pressure line Dg between the impression cylinder 11 and the cliché roller Kg.
• a similar process takes place on the printing line 13 between the plate roller Kg and the ink roller Fg.
• the effective radius Re ff decreases, which denotes the distance between the outer circumference of the plate and the axis of rotation Mg immediately before the pressure line Dg is reached again.
• this effective radius R eff is decisive for the quality of the printing process.
• the physical pressure on the printing line Dg decreases and the ink transfer to the printing material can be impaired.
• FIG. 3 uses the example of a sketched inking unit, the elements of which are provided with reference numerals without indexing the inking unit numbering, to illustrate the geometric relationships when the angle deviates from 0 °.
• the slowly rotating plate roller has a radius R during the pressing process that hardly varies over its entire circumference and is set against the impression cylinder 11.
• the position and the radius of the high-speed plate roller Kg which is shown here in broken lines, illustrates the further course of the printing process. If the printing speed increases, the radius of the plate roller relevant for the printing process decreases from R to R eff in this exemplary embodiment. In order to nevertheless guarantee an optimal ink transfer, the axis of rotation M of the plate roller is moved from the position Pi to the position P 2 . The latter position forms the center of the dashed, high-speed cliché roller K s .
• FIG. 3 shows that the plate roller Kg has a pressure line D s with the counterpressure cylinder 11 due to the provisioning process, which is located at a different location than the pressure line Di of the slowly rotating plate roller K

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Inking, Control Or Cleaning Of Printing Machines (AREA)
• Error Detection And Correction (AREA)
• Printing Methods (AREA)
• Rotary Presses (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=27588343

Family Applications (1)

Country Status (7)

Families Citing this family (5)

Family Cites Families (15)

• 2002
  • 2002-02-05 DE DE10204514A patent/DE10204514B4/de not_active Expired - Fee Related
• 2003
  • 2003-01-29 AT AT03737285T patent/ATE355969T1/de not_active IP Right Cessation
  • 2003-01-29 DE DE50306745T patent/DE50306745D1/de not_active Expired - Lifetime
  • 2003-01-29 US US10/502,042 patent/US7100509B2/en not_active Expired - Fee Related
  • 2003-01-29 EP EP03737285A patent/EP1478513B1/fr not_active Expired - Lifetime
  • 2003-01-29 AU AU2003244441A patent/AU2003244441A1/en not_active Abandoned
  • 2003-01-29 ES ES03737285T patent/ES2282642T3/es not_active Expired - Lifetime
  • 2003-01-29 WO PCT/EP2003/000882 patent/WO2003066332A2/fr active IP Right Grant

Non-Patent Citations (1)

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