Adaptive Control System for Ink Key Presetting in Offset Printing Presses

During a make ready in a web offset press it is important to produce as little waste as possible. One way to do faster make ready is to preset the ink keys of the press before it is started. This paper shows how the ink key presetting may be done through an adaptive control system, which predicts ink key presets by using a standard test pattern and the stored printing data as example data, based on the ink coverage distribution of the current print job. Such an adaptive control system for ink key presetting can be used not only for the presses with CIP3/CIP4 control interface but also for the presses without control interface, which feature is shared with a lot of older presses. Use of the developed control systems leads to higher print quality and lower ink and paper waste.