4. Control

The development of control systems for paper mills began in the 1950s with the continuous measurement of paper grammage (weight per m ² ). In 1960, the first computerized digital control system was used to measure grammage and humidity across the board. Then, in 1970, the first digital paper machine control was installed, using a mini-computer dedicated to this application. Since then, centralized control systems have been introduced, hierarchically managing all the plant's local regulation loops, followed by plant networks capable of distributing all available data to all site players.

As far as the paper machine is concerned, numerous control loops have been installed to monitor process operation and control end-of-machine paper quality. At the same time, in-line measurement techniques and sensors specific to the pulp...