Apparatus for and methods of airlaying fibrous webs having discrete particles therein

Claim 1

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: airlaying means having a foraminous forming element for forming an airlaid fibrous web; dusting layer deposition means positioned adjacent a first portion of the periphery of said airlaying means for directing a dusting layer stream of air-entrained fibers to said foraminous forming element of said airlaying means and for depositing the fibers on said foraminous forming element so as to form a dusting layer, said dusting layer deposition means having a first sector and a second sector; primary deposition means positioned adjacent a second portion of the periphery of said airlaying means for directing a primary stream of air-entrained fibers to said foraminous forming element of said airlaying means and for depositing the fibers onto said foraminous forming element over the dusting layer so as to form a primary layer over a dusting layer; dusting layer vacuum means for drawing fiber-depleted air through siad foraminous forming element, said dusting layer vacuum means being positioned subjacent said first sector of said dusting layer deposition means; and primary vacuum means for drawing fiber-depleted air through said foraminous forming element, said primary vacuum means being positioned subjacent both said primary deposition means and said second sector of said dusting layer deposition means so as to prevent the dusting layer formed on said foraminous forming element from being damaged or destroyed.

Claim 2

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: airlaying means having a foraminous forming element for forming an airlaid fibrous web; dusting layer deposition means positioned adjacent a first portion of the periphery of said airlaying means for directing a dusting layer stream of air-entrained fibers to said foraminous forming element of said airlaying means and for depositing the fibers on said foraminous forming element so as to form a dusting layer, said dusting layer deposition means having a first sector and a second sector; primary deposition means positioned adjacent a second portion of the periphery of said airlaying means for directing a primary stream of air-entrained fibers to said foraminous forming element of said airlaying means and for depositing the fibers onto said foraminous forming element over the dusting layer so as to form a primary layer over a dusting layer; dusting layer vacuum means for drawing fiber-depleted air through siad foraminous forming element, said dusting layer vacuum means being positioned subjacent said first sector of said dusting layer deposition means; and primary vacuum means for drawing fiber-depleted air through said foraminous forming element, said primary vacuum means being positioned subjacent both said primary deposition means and said second sector of said dusting layer deposition means so as to prevent the dusting layer formed on said foraminous forming element from being damaged or destroyed.

Claim 4

The apparatus of claims 1 or 2 wherein said airlaying means comprises a laydown drum-type airlaying apparatus.

Claim 5

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a first vacuum chamber, and a second vacuum chamber; a first hood positioned adjacent a first portion of the periphery of said laydown drum; a second hood positioned adjacent a second portion of the periphery of said laydown drum and adjacent said first hood; wherein said first vacuum chamber is positioned subjacent said first hood and wherein said second vacuum chamber is positioned subjacent said second hood; and wherein said first hood and said second hood intersect at at least a point of intersection and each of said first hood and said second hood has a relatively wide circular taper adjacent said point of intersection so that the shear velocity of each of a first fiber stream and second fiber stream adjacent said point of intersection is less than about 4000 feet per minute.

Claim 6

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a first vacuum chamber, and a second vacuum chamber; a first hood positioned adjacent a first portion of the periphery of said laydown drum; a second hood positioned adjacent a second portion of the periphery of said laydown drum and adjacent said first hood; wherein said first vacuum chamber is positioned subjacent said first hood and wherein said second vacuum chamber is positioned subjacent said second hood; and wherein said first hood and said second hood intersect at at least a point of intersection and each of said first hood and said second hood has a relatively wide circular taper adjacent said point of intersection so that the shear velocity of each of a first fiber stream and second fiber stream adjacent said point of intersection is less than about 4000 feet per minute.

Claim 7

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a first vacuum chamber, and a second vacuum chamber; a first hood positioned adjacent a first portion of the periphery of said laydown drum; a second hood having a first sector and a second sector, said second hood being positioned adjacent a second portion of the periphery of said laydown drum and adjacent said first hood; and wherein said first vacuum chamber is positioned subjacent both said first hood and said second sector of said second hood, and wherein said second vacuum chamber is positioned subjacent said first sector of said second hood.

Claim 8

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a first vacuum chamber, and a second vacuum chamber; a first hood positioned adjacent a first portion of the periphery of said laydown drum; a second hood having a first sector and a second sector, said second hood being positioned adjacent a second portion of the periphery of said laydown drum and adjacent said first hood; and wherein said first vacuum chamber is positioned subjacent both said first hood and said second sector of said second hood, and wherein said second vacuum chamber is positioned subjacent said first sector of said second hood.

Claim 9

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a primary vacuum chamber, and a dusting layer vacuum chamber; a dusting layer hood having a first sector and a second sector positioned downstream of said first sector, said dusting layer hood being positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary hood positioned adjacent a primary portion of the periphery of said laydown drum and adjacent to and downstream of said dusting layer hood; and wherein said primary vacuum chamber is positioned subjacent both said primary hood and said second sector of said dusting layer hood, and wherein said dusting layer vacuum chamber is positioned subjacent said first sector of said dusting layer hood.

Claim 10

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a primary vacuum chamber, and a dusting layer vacuum chamber; a dusting layer hood having a first sector and a second sector positioned downstream of said first sector, said dusting layer hood being positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary hood positioned adjacent a primary portion of the periphery of said laydown drum and adjacent to and downstream of said dusting layer hood; and wherein said primary vacuum chamber is positioned subjacent both said primary hood and said second sector of said dusting layer hood, and wherein said dusting layer vacuum chamber is positioned subjacent said first sector of said dusting layer hood.

Claim 23

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a primary vacuum chamber, and a dusting layer vacuum chamber; a dusting layer hood having a first sector and a second sector, said dusting layer hood being positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary hood positioned adjacent a primary portion of the periphery of said laydown drum and adjacent said dusting layer hood; and wherein said primary hood and said dusting layer hood intersect at at least a point of intersection, said point of intersection being positioned so that a gap between said primary hood and said dusting layer hood and the outer surface of said laydown drum is formed adjacent said point of intersection, said gap being not greater than about 1/2 inch, and wherein each of said primary hood and said dusting layer hood has a relatively wide circular taper adjacent said point of intersection so that the shear velocity of each of the primary fiber stream and the dusting layer fiber stream adjacent said point of intersection is less than about 4000 feet per minute.

Claim 24

An apparatus for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said apparatus comprising: a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a primary vacuum chamber, and a dusting layer vacuum chamber; a dusting layer hood having a first sector and a second sector, said dusting layer hood being positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary hood positioned adjacent a primary portion of the periphery of said laydown drum and adjacent said dusting layer hood; and wherein said primary hood and said dusting layer hood intersect at at least a point of intersection, said point of intersection being positioned so that a gap between said primary hood and said dusting layer hood and the outer surface of said laydown drum is formed adjacent said point of intersection, said gap being not greater than about 1/2 inch, and wherein each of said primary hood and said dusting layer hood has a relatively wide circular taper adjacent said point of intersection so that the shear velocity of each of the primary fiber stream and the dusting layer fiber stream adjacent said point of intersection is less than about 4000 feet per minute.

Claim 29

The apparatus of claims 6, 8, 13, 18 or 19 wherein said laydown drum additionally comprises a plurality of formation cavities circumferentially spaced about the periphery of said laydown drum on said foraminous forming element.

Claim 31

The apparatus of claims 6, 8, 13, 18, 19 or 23 additionally comprising an absorbent gelling material injection means for mixing discrete particles of absorbent gelling material with the primary stream of air-entrained fibers.

Claim 32

A method for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said method comprising the steps of: a. providing a dusting layer stream of air-entrained fibers; b. depositing said dusting layer stream of air-entrained fibers on a foraminous forming element to form a dusting layer; c. transferring said dusting layer to the influence of a pressure differential maintained by a vacuum means positioned subjacent the foraminous forming element while said dusting layer is still positioned under said dusting layer stream of fibers; d. providing a primary stream of air-entrained fibers; e. passing said dusting layer from under the dusting layer stream of fibers to under the primary stream of fibers while the dusting layer is under the influence of the pressure differential maintained by said vacuum means; and f. depositing said primary stream of air-entrained fibers on the foraminous forming element over said dusting layer so as to form an airlaid fibrous web having a primary layer over a dusting layer.

Claim 33

A method for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said method comprising the steps of: a. providing a dusting layer stream of air-entrained fibers; b. depositing said dusting layer stream of air-entrained fibers on a foraminous forming element to form a dusting layer; c. transferring said dusting layer to the influence of a pressure differential maintained by a vacuum means positioned subjacent the foraminous forming element while said dusting layer is still positioned under said dusting layer stream of fibers; d. providing a primary stream of air-entrained fibers; e. passing said dusting layer from under the dusting layer stream of fibers to under the primary stream of fibers while the dusting layer is under the influence of the pressure differential maintained by said vacuum means; and f. depositing said primary stream of air-entrained fibers on the foraminous forming element over said dusting layer so as to form an airlaid fibrous web having a primary layer over a dusting layer.

Claim 35

A method for forming airlaid fibrous webs having a multiplicity of layers or discret particles dispersed through at least a portion of the web, said method comprising the steps of: a. forming a dusting layer on a foraminous forming element of an airlaying drum; b. transferring said dusting layer to the influence of a pressure differential maintained by a primary vacuum chamber positioned subjacent the foraminous forming element while said dusting layer is still positioned under a dusting layer sector of the periphery of the airlaying drum; c. passing said dusting layer from the dusting layer sector to a primary sector of the periphery of the airlaying drum while said dusting layer is under the inflence of the pressure differential maintained by said primary vacuum chamber; and d. forming a primary layer on said foraminous forming element over said dusting layer so as to form an airlaid fibrous web having a primary layer over a dusting layer.

Claim 36

A method for forming airlaid fibrous webs having a multiplicity of layers or discret particles dispersed through at least a portion of the web, said method comprising the steps of: a. forming a dusting layer on a foraminous forming element of an airlaying drum; b. transferring said dusting layer to the influence of a pressure differential maintained by a primary vacuum chamber positioned subjacent the foraminous forming element while said dusting layer is still positioned under a dusting layer sector of the periphery of the airlaying drum; c. passing said dusting layer from the dusting layer sector to a primary sector of the periphery of the airlaying drum while said dusting layer is under the inflence of the pressure differential maintained by said primary vacuum chamber; and d. forming a primary layer on said foraminous forming element over said dusting layer so as to form an airlaid fibrous web having a primary layer over a dusting layer.

Claim 41

The method of claims 29, 32 or 33 additionally comprising the step of leveling said airlaid fibrous web by passing said airlaid fibrous web under a scarfing roll.

Claim 42

A method for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said method comprising the steps of: a. providing a dusting layer stream of air-entrained fibers; b. directing said dusting layer stream of air-entrained fibers toward a dusting layer sector of the periphery of an airlaying drum to a foraminous forming element positioned on the airlaying drum; c. depositing said dusting layer stream of air-entrained fibers onto the foraminous forming element; d. drawing the entrainment air through the foraminous forming element by a pressure differential maintained by a dusting layer vacuum chamber and a primary vacuum chamber positioned subjacent the foraminous forming element; e. collecting the fibers on the foraminous forming element to form a dusting layer; f. transferring said dusting layer to the influence of the pressure differential maintained by the primary vacuum chamber while said dusting layer is still positioned in the dusting layer sector of the airlaying drum; g. passing said dusting layer under the dusting layer sector to a primary sector of the periphery of the airlaying drum while the dusting layer is under the influence of the pressure differential maintained by the primary vacuum chamber; h. providing a primary stream of air-entrained fibers; i. directing said primary stream of air-entrained fibers toward the primary sector of the periphery of the airlaying drum to the foraminous forming element; j. depositing said primary stream of air-entrained fibers on the foraminous forming element over said dusting layer; k. drawing the entrainment air through the foraminous forming element by the pressure differential maintained by the primary vacuum chamber positioned subjacent the foraminous forming element; and l. collecting the fibers on the foraminous forming element over said dusting layer to form a primary layer over said dusting layer so as to form an airlaid fibrous web having a primary layer over a dusting layer.

Claim 43

A method for forming airlaid fibrous webs having a multiplicity of layers or discrete particles dispersed through at least a portion of the web, said method comprising the steps of: a. providing a dusting layer stream of air-entrained fibers; b. directing said dusting layer stream of air-entrained fibers toward a dusting layer sector of the periphery of an airlaying drum to a foraminous forming element positioned on the airlaying drum; c. depositing said dusting layer stream of air-entrained fibers onto the foraminous forming element; d. drawing the entrainment air through the foraminous forming element by a pressure differential maintained by a dusting layer vacuum chamber and a primary vacuum chamber positioned subjacent the foraminous forming element; e. collecting the fibers on the foraminous forming element to form a dusting layer; f. transferring said dusting layer to the influence of the pressure differential maintained by the primary vacuum chamber while said dusting layer is still positioned in the dusting layer sector of the airlaying drum; g. passing said dusting layer under the dusting layer sector to a primary sector of the periphery of the airlaying drum while the dusting layer is under the influence of the pressure differential maintained by the primary vacuum chamber; h. providing a primary stream of air-entrained fibers; i. directing said primary stream of air-entrained fibers toward the primary sector of the periphery of the airlaying drum to the foraminous forming element; j. depositing said primary stream of air-entrained fibers on the foraminous forming element over said dusting layer; k. drawing the entrainment air through the foraminous forming element by the pressure differential maintained by the primary vacuum chamber positioned subjacent the foraminous forming element; and l. collecting the fibers on the foraminous forming element over said dusting layer to form a primary layer over said dusting layer so as to form an airlaid fibrous web having a primary layer over a dusting layer.

Claim 48

An apparatus for forming airlaid fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said apparatus comprising: a splitting means for splitting a column of fibers into a multiplicity of fiber streams and for entraining each of the fiber streams in air so as to provide a multiplicity of streams of air-entrained fibers; a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum; a dusting layer deposition chute connected to said splitting means for directing a dusting layer stream of air-entrained fibers from said splitting means to said foraminous forming element; a dusting layer hood connected to said dusting layer deposition chute and positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary deposition chute connected to said splitting means for directing a primary stream of air-entrained fibers from said splitting means to said foraminous forming element; and a primary hood connected to said primary deposition chute and positioned adjacent a primary portion of the periphery of said laydown drum.

Claim 49

An apparatus for forming airlaid fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said apparatus comprising: a splitting means for splitting a column of fibers into a multiplicity of fiber streams and for entraining each of the fiber streams in air so as to provide a multiplicity of streams of air-entrained fibers; a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum; a dusting layer deposition chute connected to said splitting means for directing a dusting layer stream of air-entrained fibers from said splitting means to said foraminous forming element; a dusting layer hood connected to said dusting layer deposition chute and positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary deposition chute connected to said splitting means for directing a primary stream of air-entrained fibers from said splitting means to said foraminous forming element; and a primary hood connected to said primary deposition chute and positioned adjacent a primary portion of the periphery of said laydown drum.

Claim 57

An apparatus for forming airlaid fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said apparatus comprising: a splitter chute comprising: a base; four side walls extending from said base defined by a first side wall, a second side wall opposed to said first side wall, and an opposed pair of lateral side walls; a curvilinear top wall positioned on said side walls and having a plurality of ports disposed in and along the surface of said top wall and comprising a first port, and a dusting layer port, wherein a column of fibers is directed along the surface of said top wall to said ports; a first conduit duct for directing a column of air past said first port so as to cause a portion of the column of fibers to split off and be drawn into said first conduit duct to form a primary fiber stream, and for entraining the primary fiber stream in the air to direct the primary fiber stream downstream, said first conduit duct having an inlet and a discharge outlet, said first conduit duct being in communication with said first port; and a dusting layer conduit duct for directing a column of air past said dusting layer port so as to cause a portion of the column of fibers to split off and be drawn into said dusting layer conduit duct to form a dusting layer fiber stream, and for entraining the dusting layer fiber stream in the air to direct the dusting layer fiber stream downstream, said dusting layer conduit duct having an inlet and a discharge outlet, said dusting layer conduit duct being in communication with said dusting layer port; a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum; a dusting layer deposition chute connected to said splitter chute for directing a dusting layer stream of air-entrained fibers from said splitter chute to said foraminous forming element; a dusting layer hood connected to said dusting layer deposition chute and positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary deposition chute connected to said splitter chute for directing a primary stream of air-entrained fibers from said splitter chute to said foraminous forming element; and a primary hood connected to said primary deposition chute and positioned adjacent a primary portion of the periphery of said laydown drum.

Claim 58

An apparatus for forming airlaid fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said apparatus comprising: a splitter chute comprising: a base; four side walls extending from said base defined by a first side wall, a second side wall opposed to said first side wall, and an opposed pair of lateral side walls; a curvilinear top wall positioned on said side walls and having a plurality of ports disposed in and along the surface of said top wall and comprising a first port, and a dusting layer port, wherein a column of fibers is directed along the surface of said top wall to said ports; a first conduit duct for directing a column of air past said first port so as to cause a portion of the column of fibers to split off and be drawn into said first conduit duct to form a primary fiber stream, and for entraining the primary fiber stream in the air to direct the primary fiber stream downstream, said first conduit duct having an inlet and a discharge outlet, said first conduit duct being in communication with said first port; and a dusting layer conduit duct for directing a column of air past said dusting layer port so as to cause a portion of the column of fibers to split off and be drawn into said dusting layer conduit duct to form a dusting layer fiber stream, and for entraining the dusting layer fiber stream in the air to direct the dusting layer fiber stream downstream, said dusting layer conduit duct having an inlet and a discharge outlet, said dusting layer conduit duct being in communication with said dusting layer port; a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum; a dusting layer deposition chute connected to said splitter chute for directing a dusting layer stream of air-entrained fibers from said splitter chute to said foraminous forming element; a dusting layer hood connected to said dusting layer deposition chute and positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary deposition chute connected to said splitter chute for directing a primary stream of air-entrained fibers from said splitter chute to said foraminous forming element; and a primary hood connected to said primary deposition chute and positioned adjacent a primary portion of the periphery of said laydown drum.

Claim 59

An apparatus for forming airlaid fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said apparatus comprising: a curvilinear splitting member having a plurality of ports disposed in and along a surface of said splitting member and comprising a first port and a dusting layer port; a first conduit duct that is in communication with said first port of said splitting member, said first conduit duct directing a column of air past said first port to cause a portion of the column of fibers to split off and be drawn into said first conduit duct to form a primary fiber stream and entraining the primary fiber stream in the air to direct the primary fiber stream downstream; and a dusting layer conduit duct that is in communication with said dusting layer port of said splitting member, said dusting layer conduit duct directing a column of air past said dusting layer port to cause a portion of the column of fibers to split off and be drawn into said dusting layer conduit duct to form a dusting layer fiber stream and entraining the dusting layer fiber stream in the air to direct the dusting layer fiber stream downstream; a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum; a dusting layer deposition chute connected to said dusting layer conduit duct for directing a dusting layer stream of air-entrained fibers from said dusting layer conduit duct to said foraminous forming element; a dusting layer hood connected to said dusting layer deposition chute and positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary deposition chute connected to said first conduit duct for directing a primary stream of air-entrained fibers from said first conduit duct to said foraminous forming element; and a primary hood connected to said primary deposition chute and positioned adjacent a primary portion of the periphery of said laydown drum.

Claim 60

An apparatus for forming airlaid fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said apparatus comprising: a curvilinear splitting member having a plurality of ports disposed in and along a surface of said splitting member and comprising a first port and a dusting layer port; a first conduit duct that is in communication with said first port of said splitting member, said first conduit duct directing a column of air past said first port to cause a portion of the column of fibers to split off and be drawn into said first conduit duct to form a primary fiber stream and entraining the primary fiber stream in the air to direct the primary fiber stream downstream; and a dusting layer conduit duct that is in communication with said dusting layer port of said splitting member, said dusting layer conduit duct directing a column of air past said dusting layer port to cause a portion of the column of fibers to split off and be drawn into said dusting layer conduit duct to form a dusting layer fiber stream and entraining the dusting layer fiber stream in the air to direct the dusting layer fiber stream downstream; a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum; a dusting layer deposition chute connected to said dusting layer conduit duct for directing a dusting layer stream of air-entrained fibers from said dusting layer conduit duct to said foraminous forming element; a dusting layer hood connected to said dusting layer deposition chute and positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary deposition chute connected to said first conduit duct for directing a primary stream of air-entrained fibers from said first conduit duct to said foraminous forming element; and a primary hood connected to said primary deposition chute and positioned adjacent a primary portion of the periphery of said laydown drum.

Claim 61

The apparatus of claims 48 or 49 wherein said laydown drum additionally comprises a primary vacuum chamber and a dusting layer vacuum chamber, wherein said dusting layer hood has a first sector and a second sector, and wherein said primary hood and said dusting layer hood intersect at at least a point of intersection, said point of intersection being positioned so that a gap between said primary hood and said dusting layer hood and the outer surface of said laydown drum is formed adjacent said point of intersection, said gap being not greater than about 1/2 inch.

Claim 62

The apparatus of claims 48 or 49 wherein said laydown drum additionally comprises a primary vacuum chamber and a dusting layer vacuum chamber, wherein said dusting layer hood has a first sector and a second sector, and wherein said primary vacuum chamber is positioned subjacent both said primary hood and said second sector of said dusting layer hood, and wherein said dusting layer vacuum chamber is positioned subjacent said first sector of said dusting layer hood.

Claim 66

The apparatus of claims 48 or 49 additionally comprising absorbent gelling material injection means connected to said primary deposition chute for mixing discrete particles of absorbent gelling material with the primary stream of air-entrained fibers.

Claim 67

An apparatus for forming fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said apparatus comprising: a curvilinear splitting member having a plurality of ports disposed in and along a surface of said splitting member and comprising a first port, a second port, and a dusting layer port; a first conduit duct that is in communication with said first port of said splitting member, said first conduit duct directing a column of air past said first port to cause a portion of the column of fibers to split off and be drawn into said first conduit duct to form a first fiber stream and for entraining the first fiber stream in the air to direct the first fiber stream downstream; a second conduit duct that is in communication with said second port of said splitting member, said second conduit duct directing a column of air past said second port to cause a portion of the column of fibers to split off and be drawn into said second conduit duct to form a second fiber stream and for entraining the second fiber stream in the air to direct the second fiber stream downstream; a dusting layer conduit duct that is in communication with said dusting layer port of said splitting member, said dusting layer conduit duct directing a column of air past said dusting layer port to cause a portion of the column of fibers to split off and be drawn into said dusting layer conduit duct to form a dusting layer fiber stream and for entraining the dusting layer fiber stream in the air to direct the dusting layer fiber stream downstream; a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a primary vacuum chamber, and a dusting layer vacuum chamber; a dusting layer deposition chute connected to said dusting layer conduit duct for directing the dusting layer stream of air-entrained fibers from said dusting layer conduit duct to said foraminous forming element; a dusting layer hood having a first sector and a second sector positioned downstream of said first sector, said dusting layer hood being connected to said dusting layer deposition chute and positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary deposition chute connected to said first conduit duct and said second conduit duct for merging the first stream of air-entrained fibers and the second stream of air-entrained fibers and for directing the resultant primary stream of air-entrained fibers from said first conduit duct and said second conduit duct to said foraminous forming element; absorbent gelling material injection means connected to said primary deposition chute for mixing discrete particles of absorbent gelling material with the primary stream of air-entrained fibers; and a primary hood connected to said primary deposition chute and positioned adjacent a primary portion of the periphery of said laydown drum, said primary hood being positioned downstream of said dusting layer hood and intersecting with said dusting layer hood at at least a point of intersection to allow for the equalization of pressures in the portions of said dusting layer hood and said primary hood adjacent said point of intersection; wherein said primary vacuum chamber is positioned subjacent both said primary hood and said second sector of said dusting layer hood, and wherein said dusting layer vacuum chamber is positioned subjacent said first sector of said dusting layer hood.

Claim 68

An apparatus for forming fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said apparatus comprising: a curvilinear splitting member having a plurality of ports disposed in and along a surface of said splitting member and comprising a first port, a second port, and a dusting layer port; a first conduit duct that is in communication with said first port of said splitting member, said first conduit duct directing a column of air past said first port to cause a portion of the column of fibers to split off and be drawn into said first conduit duct to form a first fiber stream and for entraining the first fiber stream in the air to direct the first fiber stream downstream; a second conduit duct that is in communication with said second port of said splitting member, said second conduit duct directing a column of air past said second port to cause a portion of the column of fibers to split off and be drawn into said second conduit duct to form a second fiber stream and for entraining the second fiber stream in the air to direct the second fiber stream downstream; a dusting layer conduit duct that is in communication with said dusting layer port of said splitting member, said dusting layer conduit duct directing a column of air past said dusting layer port to cause a portion of the column of fibers to split off and be drawn into said dusting layer conduit duct to form a dusting layer fiber stream and for entraining the dusting layer fiber stream in the air to direct the dusting layer fiber stream downstream; a laydown drum having a foraminous forming element disposed about the periphery of said laydown drum, a primary vacuum chamber, and a dusting layer vacuum chamber; a dusting layer deposition chute connected to said dusting layer conduit duct for directing the dusting layer stream of air-entrained fibers from said dusting layer conduit duct to said foraminous forming element; a dusting layer hood having a first sector and a second sector positioned downstream of said first sector, said dusting layer hood being connected to said dusting layer deposition chute and positioned adjacent a dusting layer portion of the periphery of said laydown drum; a primary deposition chute connected to said first conduit duct and said second conduit duct for merging the first stream of air-entrained fibers and the second stream of air-entrained fibers and for directing the resultant primary stream of air-entrained fibers from said first conduit duct and said second conduit duct to said foraminous forming element; absorbent gelling material injection means connected to said primary deposition chute for mixing discrete particles of absorbent gelling material with the primary stream of air-entrained fibers; and a primary hood connected to said primary deposition chute and positioned adjacent a primary portion of the periphery of said laydown drum, said primary hood being positioned downstream of said dusting layer hood and intersecting with said dusting layer hood at at least a point of intersection to allow for the equalization of pressures in the portions of said dusting layer hood and said primary hood adjacent said point of intersection; wherein said primary vacuum chamber is positioned subjacent both said primary hood and said second sector of said dusting layer hood, and wherein said dusting layer vacuum chamber is positioned subjacent said first sector of said dusting layer hood.

Claim 71

A method for forming airlaid fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said method comprising the steps of: providing a column of fibers; splitting the column of fibers into a multiplicity of air-entrained fiber streams; directing a dusting layer stream of air-entrained fibers to an airlaying means; depositing the dusting layer stream of air-entrained fibers on said airlaying means to form a dusting layer; transferring said dusting layer to the influence of a pressure differential maintained by a vacuum means positioned subjacent the airlaying means while said dusting layer is still positioned under said dusting layer stream of fibers; directing a primary stream of air-entrained fibers to the airlaying means; passing said dusting layer from under the dusting layer stream of fibers to under the primary stream of fibers while the dusting layer is under the influence of the pressure differential maintained by said vacuum means; and depositing the primary stream of air-entrained fibers on the airlaying means over said dusting layer so as to form an airlaid fibrous web having a primary layer over a dusting layer.

Claim 72

A method for forming airlaid fibrous webs having a multiplicity of components each formed from a portion of a column of fibers, said method comprising the steps of: providing a column of fibers; splitting the column of fibers into a multiplicity of air-entrained fiber streams; directing a dusting layer stream of air-entrained fibers to an airlaying means; depositing the dusting layer stream of air-entrained fibers on said airlaying means to form a dusting layer; transferring said dusting layer to the influence of a pressure differential maintained by a vacuum means positioned subjacent the airlaying means while said dusting layer is still positioned under said dusting layer stream of fibers; directing a primary stream of air-entrained fibers to the airlaying means; passing said dusting layer from under the dusting layer stream of fibers to under the primary stream of fibers while the dusting layer is under the influence of the pressure differential maintained by said vacuum means; and depositing the primary stream of air-entrained fibers on the airlaying means over said dusting layer so as to form an airlaid fibrous web having a primary layer over a dusting layer.