Method for regulating the cross-machine shrinkage profile in a paper machine

摘要: To maintain the lateral profile of a running paper or cardboard web, shrinkage is adjusted during formation process. The variations are through alterations in fiber suspension composition locally to affect sections across web width, using different proportions components with behaviors. increased at section zone by raised feed fibers and/or other matter high shrinkage, replacing which shrink more strongly. reduced increasing low character shrinks less containing lower shrinkage. stock inlet wet machine. Two flows prepared, be mixed together set while weight modified controlled flow diluting water width. shrinking tendency long and vice versa, very open highly chopped ground versa. added increase carboxymethyl cellulose (CMC) matter. reduce synthetic resin strength agents like. measured, control values determined match (N) width nominal for operation actuators (7). computed on-line mapping profile, (M) machine operate accordingly. corrected correlation between measured operated as appropriate. measurement can done together. calculation weighted registered from give actuators. algorithm separates profiles. polish correlated An Independent claim included prodn. constant two zones suspensions mixtures characteristics, fed inlet. has number mixing points, sections, where into flow.