Lamellas in the nozzle of the headbox prevent troublesome vortices and generate additional micro-turbulence. This modification of the flow characteristics in the critical area of the headbox has a big impact on the jet quality. After the rebuild, the stock jet onto the wire section has no troublesome vortices and a clearly smoother jet surface. The fibers in the suspension are thus distributed more homogeneously in the paper. The influence on paper quality is manifested in an improvement of the formation and flatness of the paper and prevention of surface marks.
The turbulence insert with lamellas is used in existing headboxes without hydraulically active fittings.