Method of high fiber throughput screening
AssigneeKimberly-Clark Corporation
InventorsJames H. Dinius, Raymond Chung
Life of this patent
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Abstract
Method for improving fiber throughput in a high speed production system for forming an air-laid web of dry fibers and wherein individual fibers are separated from aggregated fiber masses in an enclosed, pressurized rotor chamber comprising forming a segment of the chamber wall with a plurality of closely spaced, elongated, narrow slots oriented parallel to the axis of the rotor chamber.
Claims9
The method of forming an air-laid web of dry fibers having a basis weight of from 7.5 to 50 pounds per 2880 square feet comprising:
- (a) delivering dry fibrous materials comprising individualized fibers and aggregated fiber masses suspended in an air stream to a rotary forming head having a forming chamber with a plurality of rotating rotor bars therein positioned over a forming surface;
- (b) conveying the dry fibrous materials through the forming head in a moving aerated bed of individualized dry fibers and aggregated fiber masses and in an environment maintained substantially free of fiber grinding and disintegrating forces;
- (c) continuously separating and discharging from the forming head from 1% to 10% of the fibrous materials from the aerated bed having a bulk density in excess of 0.2 g/cc.
- (d) discharging the individualized fibers from the forming head through a high capacity slotted screen at a fiber throughput rate from about 0.5 lbs./hr./in..sup.2 to about 1.50 lbs./hr./in..sup.2 ;
- (e) conveying said individualized fibers from said forming head through an enclosed forming zone to a moving foraminous forming surface whereby, an air-laid web of individualized fibers is formed on said foraminous forming surface.
The method of forming a quality web of air-laid dry fibers on a high speed production basis comprising the steps of:
- (a) delivering dry fibrous materials to a forming head positioned over a forming surface;
- (b) conveying the dry fibrous materials through the forming head in a rapidly moving aerated bed of individualized fibers, soft fiber flocs and aggregated fiber masses and in an an environment maintained substantially free of fiber grinding and disintegrating forces;
- (c) continuously separating from 1% to 10% of the fibrous materials delivered to the forming head from the aerated bed with the materials being separated including those having a bulk density in excess of 0.2 g/cc. so as to maximize the separation of aggregated fiber masses from the aerated bed;
- (d) discharging such separated fiberous materials including the aggregated fiber masses contained therein from the forming head;
- (e) discharging the individualized fibers and soft fiber flocs through a high capacity slotted screen;
- (f) conveying the individualized fibers and soft fiber flocs discharged through the slotted screen at a fiber throughput rate anywhere in the range of 0.5 lbs./hr./in..sup.2 to at least 1.50 lbs./hr./in..sup.2 through an enclosed forming zone towards the moving foraminous forming surface in a rapidly moving air stream;
- (g) air-laying the individualized fibers and soft fiber flocs on the moving foraminous forming surface so as to form an air-laid web of randomly oriented dry individualized fibers and soft fiber flocs on the forming surface with such web having a nit level of from "0" to "3";
- and,
- (h) moving the foraminous forming surface at a controlled and selected speed so as to produce an air-laid web having a nit level of from "0" to "3" and any specific desired basis weight in lbs./2880 ft..sup.2 ranging from at least as low as 13 lbs./2880 ft..sup.2 to in excess of 40 lbs./2880 ft..sup.2.
Dependencies are inferred from the claim text.