Method for determining time for introduction of roll change in roll changer for rotary printing presses, involves releasing roll change signal when falling below minimum remainder layer thickness

摘要

The method involves determining a paper layer thickness (p) at a remainder roll (04). A roll change signal is released when falling below a minimum remainder layer thickness, which causes adhesion of the upper position of a new material roll (09) to the material web (06) proceeding from the remainder roll. A number of remainder paper positions are determined from the determined minimum remainder layer thickness. The roll change is introduced during shortfall of a number of remainder positions. An independent claim is also included for a device for measuring paper layer thickness at a remainder roll in a roll changer.