Headbox nozzle with heavy end convergence

摘要

A nozzle of a multilayer headbox wherein the headbox includes a nozzle for distributing the stock suspension on a wire. The nozzle is subdivided by at least one machine-wide fin, the fin forming with the nozzle at least two machine-wide nozzle ducts. At least the mean value of the clearance of at least one nozzle duct diminishes steadily in the flow direction, the percentage decrease of the clearance in the fluidically essential area of the nozzle being at least twice as large as in the starting area of the nozzle. The fin has downstream end area of decreasing thickness immediately preceded by an area of increasing thickness.