Patent ID: 6890408
Filing Date: 2005-05-10
Classification: D21F

Abstract:
1. A headbox for, one of, a paper and cardboard machine, comprising: at least one material suspension supply running a width of said machine; at least one turbulence producer having at least one conduit through which a material suspension flows; at least one metered addition point located in said conduit for introducing a fluid medium; a mechanism that increases flow resistance arranged within the at least one conduit between an entrance region and an exit region of the least one conduit, wherein the mechanism is located one of adjacent the at least one metered addition point and downsteam of the at least one metered addition point; and a headhox nozzle located downstream from said at least one turbulence producer for delivering said material suspension; wherein a portion of a flow resistance located downstream of said at least one metered addition point is at least approximately 50% of a total flow resistance of said at least one conduit.