Page mark
Page mark is a term used in printing technology. It describes a mechanical assembly that precisely aligns a sheet of paper entering the printing press laterally, transversely to the direction of sheet travel. According to the Fogra standard, an accuracy of 0.015 mm is required.
The sheet coming from the sheet feeder is first brought to a standstill at the front lays and then moved against a lateral stop by means of the side mark. The lateral alignment of a printed sheet is done at the side mark with the help of slide or pull marks . This refers to the machine elements that ensure that the sheet is in the exact position before it is transferred to the printing units.
Push marks are more simply constructed and are preferred over pull marks for smaller print formats. Sliding marks have a slide that acts transversely to the transport direction and can be moved a few millimeters laterally against the stop to align the sheet. High-speed, large-format machines are generally equipped with pull lays . These tighten the leading edge of the sheet and smooth out curled edges. A sheet that has been tightened at the front edge across the transport direction can be transferred more precisely by the gripper systems. In a modern printing press there is a sidelay on the left and right side, which can be operated optionally.
The development of sensors and actuators makes it possible to measure and position the sheet while the machine is running. From 2004 machines with such systems will be offered for sale.
See also
literature
- Helmut Kipphan (Hrsg.): Handbuch der Printmedien. Technologies and production processes. Verlag Springer, Berlin et al. 2000, ISBN 3-540-66941-8 .