METHOD FOR EXECUTING GRADE CHANGE ON A PAPER MACHINE

摘要

The invention relates to a method and system for executing grade change in a paper machine. In the method, a controller (120) controls at least two input variables affecting the paper machine process, which variables affect the same output variable which represents the property defining the paper grade. The controller (120) controls at least one input variable toward the setting of the second grade before the grade change while the first grade is being manufactured. The controller (120) compensates the impact of said input variable on the output variable with at least a second input variable to keep the output variable substantially unchanged until the end of the manufacture of the first grade. Corresponding action can also be taken at the end of the grade change.