Patent ID: 6368460
Filing Date: 2002-04-09
Classification: D21F

Abstract:
A paper forming machine headbox component for receiving a paper fiber stock and generating a jet therefrom for discharge upon a wire component moving in a machine direction (MD), the headbox component comprising:a distributer for distributing stock flowing into the headbox component in a cross-machine direction (CD), the distributer effective for supplying a flow of said stock across the width of the headbox in the machine direction; a nozzle chamber having an upper surface and a lower surface converging to form a rectangular outlet lip defining a slice opening for the jet; a diffuser block coupling said distributer to said nozzle chamber, said diffuser block comprising a multiplicity of tubular elements disposed between said distributer and said nozzle chamber, said tubular elements being oriented axially in the machine direction, a plurality of the tubular elements having a longitudinal axes in the direction of the flow of stock, and the tubular elements arranged within the diffuser block as a matrix of rows and columns for generating multiple jets of said stock flowing into said nozzle chamber; and said tubular elements being oriented axially generate an axial vorticity which prevents fiber orientation in the machine direction in an initial converging section of said nozzle chamber comprising a plurality of fins effective for swirling said stock in controlled pairs of axial vortices along the longitudinal axes of the tubular elements as said stock flows through said tubular elements promoting mixing of the jets of said stock as said jets flow into said nozzle chamber from the tubular elements to form a uniform flow of stock at the slice opening for the jet.