Headbox and stock delivery system for a papermaking machine

Abstract

A headbox including a stock dilution profiling arrangement and associated stock delivery systems are provided, which together deliver to the forming section of a papermaking machine a uniform stock flow with more consistent basis weight and fiber orientation profiles than has previously been possible. These improvements in basis weight uniformity and fiber orientation profile provide benefits in paper sheet formation and related paper properties.

Description

[0001] The present invention relates to stock delivery systems for papermaking equipment and more particularly to a stock distributor and headbox arrangement to provide stock of uniform consistency across the width of the paper machine. Background technique [0002] Known existing paper machine headboxes and stock delivery systems are all about varying the degree to which the stock flow is evenly distributed and evenly across the width of the paper machine, ideally, the amount of fiber per unit area across the width of the machine and along the machine direction (weight basis weight). (basis weight) should be kept fixed. [0003] The first step in converting the stock flow from a circular pipe providing an initial delivery of stock white water to a thin rectangular stock flow from the headbox (the stock jet) consists in using a manifold device (manifold device) to evenly distribute the slurry flow, or feed it to the headbox, before the 1960s, different types of slurry flow dis...

AI Technical Summary

Problems solved by technology

[0003] The first step in converting the stock flow from a circular pipe providing an initial delivery of stock white water to a thin rectangular stock flow from the headbox (the stock jet) consists in using a manifold device (manifold device) to evenly distribute the slurry flow, or feed it to the headbox, before the 1960s, different types of slurry flow distributors were used, and different piping configurations were used. These are now The main problem with the design was that the slurry flow was not uniform across the machine, usually the delivery pipe closest to the input connection would receive the most slurry flow, leaving the other delivery pipes with no flow, and finally, in the early 1960's, the A tapered manifold system was developed to achieve a more uniform distribution of the slurry flow. This system is still widely used today, but it often causes problems in the distribution of the slurry flow

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