Abstract
Modifications on paper machines are very expensive and the test runs are very difficult to perform in the production process. Therefore, a tool than can predict accurately the outcome of modification would be very useful. In cooperation with S. C. Letea S. A. started in April 2003 to develop a computer simulation model to describe the dewatering process of the paper web on the paper machine starting with the press and dryer section. The paper presented some aspects of this problem.