Method of operating a flexographic printing press, flexographic printing press, system and sleeve

Patent metadata

Field	Value
Publication number	US-11865830-B2
Application number	US-202117507896-A
Country	US
Kind code	B2
Filing date	Oct 22, 2021
Priority date	Oct 22, 2020
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A method of operating flexographic printing presses having an impression cylinder, printing cylinder carrying a sleeve with a flexographic printing forme or cylinder, uses a sensor adjusting print register of the printing forme or cylinder relative to a further printing forme or cylinder and/or adjusts color density and/or implements color inspection. An image of the sleeve surface with printing forme is recorded by a camera and processed before printing, locating a register mark and/or a color measurement field in terms of x-y positions. A sensor automatically moves for recording the register mark to the y-position of the register mark before adjusting to record the register mark and/or a sensor moves for recording the color measurement field to the y-position of the color measurement field before adjusting to record the color measurement field. Cost-efficient, high-quality industrial printing and further automation is provided.

First claim

The invention claimed is:

1. A method of operating a flexographic printing press and a measuring device, the method comprising:
providing a flexographic printing press including at least one printing unit having a printing cylinder, a sleeve associated with the printing cylinder, a flexographic printing forme carried by the sleeve, and at least one sensor;
marking the sleeve with a machine-readable ID and providing the machine-readable ID as an unambiguous identifier of the respective sleeve;
providing a measuring device with a camera, the measuring device being different from the flexographic printing press;
providing a computer;
defining an x-direction as a circumferential direction of the sleeve, and defining a y-direction as a direction perpendicular to the x-direction being an axial direction of the sleeve;
recording respective images of surfaces of the sleeve in the measuring device by using the camera before a printing operation;
subjecting the respective image to pattern detection using the computer including searching for a defined pattern of a register mark to locate a total of at least two register marks in terms of x-positions and y-positions of the register marks before a printing operation and saving the x-positions and y-positions in association with the machine-readable ID;
making the machine-readable ID available to the flexographic printing press when the sleeve is mounted on one of the printing cylinders;
accessing the saved x-positions and y-positions in association with the machine-readable ID and automatically moving the sensors to the y-position of the respective register marks using respective actuating motors to record the register marks in the flexographic printing machine before a register adjustment;
using x-y position data of the respective register marks to record the register marks in the flexographic printing machine using the sensors;
adjusting the print register by controlling print register of the sleeve carrying the flexographic printing forme using the recorded register marks; and

performing the printing operation using the adjusted print register.

2. The method according to claim 1 , which further comprises including an entire circumferential length and a working width of the sleeve in the image.

3. The method according to claim 1 , which further comprises selecting one of the register marks from recorded data to adjust the print register when multiple register marks are located on the sleeve in terms of x-y positions thereof.

4. The method according to claim 3 , which further comprises using the recorded data to determine which register mark of a configuration of register marks is printed in which printing unit of a plurality of printing units of the flexographic printing press, to adjust the print register.

Assignees

• Heidelberger Druckmasch Ag

Inventors

• Schwab Werner

Classifications

• B41F5/24 Primary

  for flexographic printing · CPC title

• B41F13/14

  with means for displacing the cylinders · CPC title

• B41F13/24

  Cylinder-tripping devices; Cylinder-impression adjustments · CPC title

• B41F33/0081

  Devices for scanning register marks · CPC title

• B41F33/14 Primary

  Automatic control of tripping devices by feelers, photoelectric devices, pneumatic devices, or other detectors · CPC title