5. Modelling and process control

The models developed in this way provide a good approximation to reality; the forces exerted on the cylinders and their drive torques are predicted to within 20% (see [8] ). These models are therefore useful for dimensioning the calender (diameter of cylinders and their bearings, engine power, frame rigidity).

• These models provide a relevant understanding of the sensitivity of calender forces to calender setting parameters.

We can see (figure 26 a and b) that the choice of behavior law is crucial: