Modeling of roll offset printing processes

Abstract

The relevance of the work is contained in the automation of the printing process management, which allows to achieve an increase in printing speeds. This problem is especially relevant for roll offset printing, which expresses the most progressive trends in the development of printing equipment and technology. The purpose of the article was to determine the mechanism of forming a structural-mathematical model of control objects related to the movement of the paper tape of the offset printing process. In roll offset printing machines, the synchronous drive of the paper feeding cylinders is provided by continuous gear transmission. Due to the mechanical flexibility of the transmission, the system is prone to torsional oscillations, which are excited by many phenomena. Fluctuations in gear transmission affect print quality. The excitation frequencies or orders on the printing press lead to lead errors with the corresponding orders on the printed sheets. Using a mechanical model of a printing press, it is possible to simulate the effect of excitation on the system and thus make a prediction of the change in the actuation using the sheet tracking algorithm. By compensating the excitation (feedback control), the torsional vibrations of the machine can be suppressed and, thus, print quality can be ensured. This is shown both from simulations and taking into account measured data. In this way, the impact of mechanical or control-related changes in the design of the printing press can be predicted, ultimately saving time and money in machine development and production.