Tension control of webs in rotary press

摘要

A rotary press system has a number of reel stands (1), webs (2), printing units (3) guiding rollers (4-11) a triangular plate (8), loads (12-14) for controlling the tension of the webs and tension detectors (15). The tension of each web is detected and calculated by a computer (16). By comparing it with a predetermined desired value, a control signal for each load (12-14) is calculated so that the tension of the web before the triangular plate is regulated at a certain value. The control is based on the mathematical relation between the pressing load and the tension, considering strain, friction and elasticity coefficients.