Device and Method for Measuring and Setting the Web Tension Between Inking Stations of a Multicolor Press

Method for measuring and setting the web tension on a printing press (8) comprising several inking units (Dn), in which method measuring means (Mm,n) are used for measuring the web tension and setting means (Fn) are used for setting the web tension, said method being characterized in that

• the at least one measuring means (Mm,n) records measured values of the web tension between two inking units (Dn)
• and the at least one setting means adjusts the web tension between the print areas of these two inking units (Dn) based on the measured values,
• and a control device is used, which controls the at least one setting means based on the measured values of the at least one measuring means (Mm,n).

Method according to the preceding claim characterized in that web-guiding elements determining the course of the web of printable material (3) are used as setting means (Dn) [sic:

• (Fn)].

Method according to the preceding claim characterized in that the cylinders (Fn) carrying the print image are pre-positioned before the setting process, this pre-positioning being effected preferably while the related cylinder carrying the print image is lifted off from the web (3).

Method according to the preceding claim characterized in that the cylinders (Fn) carrying the print image are pre-positioned before the setting process around the angular amount (α) required for setting the web tension, the pre-positioning (α) and the setting (−α) having unlike algebraic signs.

Method according to the preceding claim characterized in that, in the pre-registering method, a web of printable material provided with a web marking is guided through at least two printing units (Fn) [sic:

• (Dn)], and the time at which the marking passes through the print zones of the at least two inking units (Dn) is recorded and these measured values are taken by the machine control system as the basis for pre-registration.

Method according to the preceding claim characterized in that the first controlled variation in web tension by a predetermined amount is followed by at least another controlled variation in web tension.

Method according to the preceding claim characterized in that the control device records, in a storage unit, the amount and the algebraic sign of the setting processes (Hn) which are performed until the algebraic sign of the automatically set variation in web tension changes or until the automatically set variation in web tension is no longer measurable, and the control device adjusts this amount and/or algebraic sign during the subsequent occurrence of an unsteady web tension condition.

Method according to the preceding claim characterized in that the calculation unit takes into account specific data of the print job—such as the type and thickness of the printed materials—when calculating the amount and algebraic sign of the setting processes.

Method according to the preceding claim characterized in that, in the storage device, the amount and the algebraic sign of completed or calculated setting processes are assigned to specific data of that print job—such as the type and thickness of the printed materials (3)—during which the related settings were made.

Method according to the preceding claim characterized in that the measurements and settings are performed in at least two regions in the order, in which the web of printable material (3) passes through the printing press.