Assembly on paper machines for setting a surface weight cross-section

Abstract

A facility on the paper making machine modulates the quantitative transverse distribution of the diluted water at the stock discharge box for paper making or plate making, includes a machine width entering chamber including a paper pulp stream cross flow distributor, a diluted water cross flow distributor and a stock discharge box; the paper pulp stream cross flow distributor is connected to n cross section volume stream supply channel that can be divided by 2, wherein two of which are respectively connected to a mixing device; at an export side, each mixing device has a mixing cross section volume stream discharging pipe connected to entering chamber; the flow resistances respectively connected to the cross section volume stream supply channel of mixing device are about equally to each other, and are smaller than the flow resistance of the mixed cross section volume stream discharged tube; the diluted water cross flow distributor has n / 2 diluted water supply channels; each mixing device has a centre hole, for mounting diluted water supply channels with controllable input variable at various instances, and is arranged between two cross section volume stream supply channel; a valve for passing diluted water with controllable input variable is provided at the centre hole of each mixing device.

Description

technical field [0001] The invention relates to an arrangement on a paper machine for adjusting the basis weight CD profile with dilution water at the headbox for paper or board production. Background technique [0002] Due to the need for increased web quality, transverse distribution adjustment with dilution water is required, for which the uniformity of fiber orientation over the entire width of the paper or board web plays an increasingly important role. The stock volume is finely regulated across the width by mixing additional dilution water into the manifold. This applies in particular to the manufacture of specialty papers. [0003] Specifically, specialty paper includes filter paper, non-woven and decorative paper. Filter papers and nonwovens have a high proportion of chemical pulp and synthetic fibers. Chemical pulp and synthetic fibers tend to form plugs in the flowing fiber suspension, ie the pulp stream. Therefore, the headbox must be designed to avoid the fo...

AI Technical Summary

Problems solved by technology

The substantial disadvantage of this throttling device is that this swirling flow guidance of white water with synthetic fibers generates plugs which lead to cracks in the paper web

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