Method of forming a multi-ply web from paper stock
AssigneeBeloit Corporation
InventorJan I. Bergstrom
Life of this patent
Estimating the term…
Abstract
A method of forming a multi-ply web by providing upper and lower outer surface plies of low consistency stock on an intermediate high consistency stock layer joined and delivered from a slice chamber for producing a smooth finished web. A stream of high consistency stock is subjected to highly efficient fiber distributing agitation and stabilization in a tortuous path, and then joins the high consistency stock as an intermediate ply layer between the low consistency stock ply layers. The flow of the intermediate ply layer to juncture with the outer ply layers is modulated and smoothed so that the outer ply layers on the intermediate ply layer will present substantially smooth outer surfaces for the multi-ply paper web.
Claims10
A method of making high strength smooth surfaced paper from stock having a slurry of fibers in a liquid carrier, comprising:
- delivering high consistency fibrous stock to the upstream end of a rigid stock flow passageway of substantially uniform depth throughout its length communicating at its downstream end through a slice with paper web forming surface means, and in said passageway:
- a. driving the stock from a straight-on upstream machine direction axis section through an abrupt right angular juncture into and then through an elongated straight jog section which extends substantially right angularly relative to the machine direction axis of the slice chamber,
- b. from said jog section driving the stock through an abrupt turn acute angle juncture with some pressure drop, and then downstreamwardly through an elongated straight slanting passageway section to and through an abrupt turn obtuse angle juncture into a sinuous passageway section, and therein
- c. driving the stock through a plurality of smoothly curving sinuous loops which diminish progressively in length and height in a downstream direction
- d. and from the downstream end of said sinuous section conducting the stock through a straight-on downstream stabilizing terminal section of substantial length to the downstream end of said passageway;
- and in said jog and slanting sections and said abrupt juncture vigorously agitating the stock and effecting substantially uniform distribution of the fibers in the stock, and maintaining such distribution throughout the sinuous and straight-on terminal sections to the downstream end of said passageway, while modulating and smoothing of the stock in said terminal section.
A method of forming a multi-ply smooth surfaced paper web from stocks having a slurry of fibers in a liquid carrier, comprising the steps of:
- delivering from respective upper and lower slice chamber portions low consistency fibrous stock to a slice opening for providing upper and lower outer surface ply layers for a finished web;
- maintaining fine scale fiber distributing turbulence in the low consistency stock in said upper and lower slice chamber portions;
- delivering and driving a stream of high consistency fibrous stock into the upstream end of, and then through, a path in a rigid intermediate portion of the slice chamber having its downstream end adjacent to said slice opening;
- in an upstream part of said path turning said stream from a straight-on section abruptly through a right angular juncture into a substantially right angular elongated straight jog section, then turning the stream abruptly at an acute angle from the downstream end of said jog section into the upstream end of a downstreamwardly elongated straight slanting section of substantial length, and from the downstream end of said slanting section abruptly at an obtuse angle turning the stream into the upstream end of a sinuous section extending downstream from said slanting section, and in said jog and slanting sections and said abrupt junctures subjecting said high consistency stock to vigorous fiber distributing agitation and attaining thorough and substantially uniform distribution of fibers in the stream;
- in said sinuous section driving the high consistency stock through a plurality of smoothly curving sinuous loops which diminish progressively in length and height in a downstream direction and thereby maintaining said uniform fiber distribution;
- modulating and smoothing flow of said stream in a straighton downstream terminal section of said path;
- discharging said modulated and smooth high consistency stock stream from the downstream end of said terminal section and joining as an intermediate ply layer between said low consistency outer ply layers;
- and causing said outer ply layers to form on said intermediate ply layer smooth outer surfaces for the multiply paper web.
Dependencies are inferred from the claim text.