Printing press and method for operating a dryer device that comprises a dryer and a control device in a printing press

Abstract

A dryer device for a printing press that prints in at least one printing position on a printing substrate by use of at least one printing unit, in particular a printing press for securities, includes a dryer with a drying unit formed by an array of a plurality of adjacent radiation sources. That array extends at least over the maximum width of the printing substrate and is used to supply radiation to the printing substrate in each activated state for drying the latter. A control device allows the radiation sources or some of the radiation sources to be switched on or off in a repeating cycle that comprises a sequence with at least one active and at least one inactive phase in correlation with one of a press and a printing-substrate phase position. The dryer device comprising the dryer and the control device is configured to switch on and switch off, for each cycle, only some of the radiation sources in some sections in at least four pre-definable radiation-source groups, spaced approximately equidistantly, i.e. at a distance deviating by a maximum 20% from the average distance and transversely to a transport direction, one of concurrently and collectively according to a sequence comprising one of multiple and at least three equidistant active phases of the same first lengths. The invention also relates to a printing press, in particular to a printing press for securities, comprising a dryer device of this type. During operation, the printing substrate is supplied with radiation in multiple tracks spaced apart transversely to the transport direction, synchronously with one of the printing substrate feed and with the press phase.