Movable foil blade for papermaking on a fourdrinier, including the lead blade on the forming board box

摘要

A method for operably adjusting a forming board lead blade of a paper sheet forming machine of the type having a headbox for impinging a jet of slurry from a slice opening of the headbox onto the surface of a porous wire moving continuously in a horizontal machine direction over the forming board.

主权项

1. An apparatus for moving a lead blade only of a forming board box on a fourdrinier paper machine having a headbox for impinging a jet of slurry from a slice opening of the headbox onto a surface of a porous forming fabric moving continuously in a horizontal machine direction over the forming board, the apparatus comprising:
a) a lead blade having multiple guide bars formed on a bottom of the lead blade at an oblique angle “X” to the cross machine direction wherein guide bars are spaced along the full length of the lead blade to ensure the leading edge of the said blade stays parallel to the apron of the headbox throughout an adjustment range; b) a slide base with multiple grooves that match guide grooves formed on the bottom of lead blade; c) means for adjustment of the lead blade only while leaving the rest of the forming board drainage elements stationary accomplished by either a manual or automatic device attached to either end of the lead blade to move the lead blade to position to achieve the best formation and sheet structure for optimizing a jet landing while not altering the proper spacing on the remaining drainage elements in the forming board box enabling maintaining proper harmonics in the critical initial forming zone of the fourdrinier.