Abstract:
A method for forming air-laid fibrous articles. The method includes the steps of providing a stream of loose air-entrained fibers, providing a core pocket assembly comprising a central foraminous forming surface and an edge foraminous forming surface, applying a first pressure to the central foraminous forming surface, applying a second pressure to the edge foraminous forming surface wherein the second pressure applied to the edge foraminous forming surface differs from the first pressure applied to the central foraminous forming surface, depositing a portion of the stream of loose air-entrained fibers on the central foraminous forming surface, and depositing a portion of the stream of loose air-entrained fibers on the edge foraminous forming surface.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a method for making air-laid articles. 
       BACKGROUND OF THE INVENTION 
       [0002]    Air-laid structures are widely used in the art of absorbent articles and other arts in which fibrous webs are of use. One common approach for creating air-laid structures is to process a fibrous sheet of cellulosic fibers or other suitable fibers through a device that breaks up the fibrous sheet, thereby forming discrete fibers. The discrete fibers are entrained in a stream of air and directed to a foraminous forming surface upon which the fibers are deposited to form fluff. Typically, fluff has a high porosity and is comprised of essentially randomly oriented fibers. In some processes, a vacuum is applied to one side of the foraminous surface to create a pressure differential across the foraminous forming surface to assist with drawing the discrete fibers to the foraminous forming surface. 
         [0003]    Absorbent articles such as sanitary napkins, diapers, and adult incontinence products commonly employ air-laid structures in the absorbent core. Absorbent cores have a generally planar structure in which the thickness is generally smaller than the planar dimensions. One common approach to forming air-laid absorbent articles is to situate the foraminous surface in a recess. In the art, the structure in which the foraminous surface is emplaced and the foraminous surface are components of what is commonly referred to as a core pocket. The thickness can be partially controlled by the depth of the recess in the core pocket and the planar dimensions of the absorbent core can be defined by the dimensions of the recess and the foraminous surface 
         [0004]    Absorbent cores having a variable thickness are thought to fit wearers better and to have better fluid acquisition properties. Absorbent cores in which the thickness of the absorbent core varies can be created by using a foraminous surface that is contoured in the thickness dimension. Thus, different quantities of fibers are required to fill different portions of the core pocket. One problem with filling a contoured foraminous surface to form an absorbent core having variable thickness is that a substantial amount of scarfing may need to be performed on the core to render the core flat on the side of the pad opposing the contoured side, which is the typical construction of many types of absorbent cores. For absorbent cores such as those used in sanitary napkins, the contoured side can be the body facing surface and a flat garment facing side can be desired or vice versa. 
         [0005]    During formation of the article, the fibers filling a core pocket having a foraminous surface that is contoured in the thickness dimension can be thought of as being like snow falling in a ditch. When enough snow has fallen such that the level of snow in the deepest portion of the ditch is even with the level of the ground surrounding the ditch, the level of the snow above the shallower edges of the ditch will be above the level of the surface of the ground surrounding the ditch. Thus, to make the level of snow in the ditch even or flat, snow above the shallower edges of the ditch needs to be scarfed away to be even with the level of snow in the deepest portion of the ditch. An analogous situation arises in air laying fibrous articles having a contoured thickness in which one surface is desired to be flat. 
         [0006]    Scarfing imparts mechanical energy to the fibrous articles which can result in uncontrollable changes in the basis weight and structure of the fibrous articles. Many designers of absorbent articles recognize that small variations in the basis weight and structure of absorbent cores can have significant impacts on the fluid acquisition and retention properties of absorbent articles. Uncontrolled variations in basis weight within a single absorbent core and uncontrolled variations in basis weight between multiple absorbent cores formed on a single manufacturing line can be unacceptable to manufacturers of absorbent articles because consumers demand that absorbent articles sold under a particular brand name perform consistently. Furthermore, scarfing can result in wasted fibrous material and if the scarfed fibrous material is recycled, some of the fibers can be damaged by scarfing. 
         [0007]    Absorbent cores having a basis weight that varies in plane can be desirable. The partially saturated fluid acquisition and retention properties of air-laid absorbent cores are known to vary as a function of basis weight. For instance, some designers of absorbent articles designed to be worn close to the human body desire an absorbent core in which the basis weight of the center of the absorbent core is greater than the basis weight of the periphery of the absorbent core. For some designs of absorbent articles, precise variations in basis weight in the machine direction and cross direction can be helpful with achieving optimum performance of the absorbent article. 
         [0008]    With these limitations in mind, the problem remains with providing an apparatus to manufacture air-laid fibrous articles in which the basis weight can vary in plane. There is a further unmet need for providing an apparatus in which the variation in the basis weight in the machine direction and cross direction can be precisely controlled. There is an additional unmet need for an apparatus for forming air-laid fibrous articles in which the amount of excess fibrous material deposited is minimized. 
       SUMMARY OF THE INVENTION 
       [0009]    A method of forming an air-laid fibrous article is disclosed. The method comprises the steps of providing a stream of loose air-entrained fibers, providing a core pocket assembly comprising a central foraminous forming surface and an edge foraminous forming surface, applying a first pressure to the central foraminous forming surface, applying a second pressure to the edge foraminous forming surface wherein the second pressure applied to the edge foraminous forming surface differs from the first pressure applied to the central foraminous forming surface, depositing a portion of the stream of loose air-entrained fibers on the central foraminous forming surface, and depositing a portion of the stream of loose air-entrained fibers on the edge foraminous forming surface. 
         [0010]    The first pressure can be negative and less than the second pressure. The second pressure can be negative and less than the first pressure. The second pressure can be positive. The second pressure can be negative. The second pressure can be ambient pressure. 
         [0011]    The method can further comprise the step of scarfing the air-laid fibrous article to remove excess fibers. 
         [0012]    The method can further comprise the steps of providing a stream of recycled loose air-entrained fibers, applying a third pressure to the central foraminous forming surface, applying the second pressure to the edge foraminous forming surface wherein the second pressure differs from the third pressure depositing a portion of the stream of recycled loose air-entrained fibers on the central foraminous forming surface, and depositing a portion of the stream of recycled loose air-entrained fibers on the edge foraminous forming surface. 
         [0013]    The third pressure can be negative and less than the second pressure. The second pressure can be negative and less than the third pressure. The second pressure can be negative. 
         [0014]    The method can further comprise the steps of applying a fourth pressure to the central foraminous forming surface, applying a fifth pressure to the edge foraminous forming surface, and scarfing the air-laid fibrous article to remove excess fibers. 
         [0015]    The fourth pressure and the fifth pressure can be negative. 
         [0016]    The second pressure and the third pressure can be less than the fourth pressure and the fifth pressure. 
         [0017]    The method can further comprise the step of transporting the excess fibers upstream to provide the stream of recycled loose air-entrained fibers. The excess fibers can be transported upstream through a recycle duct. 
         [0018]    The air-laid fibrous article can be a core for a sanitary napkin. The air-laid fibrous article can be a core for a diaper. The air-laid fibrous article can be a core for an incontinent article. The air-laid fibrous article can be a core for an absorbent article designed to be worn in proximity to the crotch of the wearer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is an illustration of a side view of one embodiment of an apparatus for forming air-laid fibrous articles. 
           [0020]      FIG. 2  is an exploded view of a core pocket. 
           [0021]      FIG. 3  is a bottom view of a core pocket. 
           [0022]      FIG. 4  is a cutaway view of a core pocket with the central support mesh and edge support mesh exposed. 
           [0023]      FIG. 5  is a cutaway view of one embodiment of the core pocket, as indicated by Section  5 - 5 . 
           [0024]      FIG. 6  is a perspective view of one embodiment of the core pocket. 
           [0025]      FIG. 7  is a cross sectional view of a core pocket comprising a plurality of central forming chambers in an edge forming chamber, the core pocket being mounted on a deposition drum (viewed from the opposite side as the view provided in  FIG. 1 ). 
           [0026]      FIG. 8  is a perspective view of one embodiment of an air-distribution manifold. 
           [0027]      FIG. 9  is a cutaway view of one embodiment of an air-distribution manifold. 
           [0028]      FIG. 10  is schematic of how components of the core pocket can be operatively related to the air-distribution manifold. 
           [0029]      FIG. 11  is a schematic of an embodiment of the air-distribution manifold in which the air-distribution surface is flat. 
           [0030]      FIG. 12  is a cutaway view of apparatus  10 , as indicated by Cutaway  12 . 
           [0031]      FIG. 13  is a cross sectional view of  FIG. 1  looking upstream in the machine direction, as indicated by Section  13 - 13 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    An illustration of one embodiment of an apparatus  10  for forming air-laid fibrous articles is shown in  FIG. 1 . The apparatus  10  can comprise a hammermill  20 , or other suitable apparatus such as a disk mill or lickerin or other apparatus for disassociating fibers of a drylap web, into which a drylap web  8  can be fed through an infeed slot  25 . The hammermill  20  disassociates the fibers of the drylap web and then discharges a relatively high velocity stream of loose air-entrained fibers  12  that is directed through discharge chute  30  generally towards a core pocket  50 . A fiber source entrance chamber  380  can be connected to the discharge chute  30  to assist with distributing the fibers over the core pocket  50 . One or more core pockets  50  can be disposed in a circumferential relationship about the periphery of deposition drum  40 . The core pockets  50  can have a foraminous forming surface. Deposition drum  40  can rotate about air-distribution manifold  60 . Air-distribution manifold  60  can be in air-flow communication with one or more core pockets  50  as deposition drum  40  rotates about air-distribution manifold  60 . As the core pocket  50  rotates near or past the discharge chute  30 , air-distribution manifold  60  can apply a vacuum to at least a portion of the core pocket  50 . The vacuum combined with the momentum of the fibers  12  discharged through discharge chute  30  act to draw and direct, respectively, the air-entrained fibers  12  into at least a portion of the core pocket  50  as the core pocket  50  rotates about air-distribution manifold  60  through a region near or past the discharge chute  30 . As the air-entrained fibers impinge upon the foraminous forming surfaces of the core pocket  50 , the fibers are retained on the foraminous forming surfaces and the air passes through the foraminous forming surface. Other embodiments of the apparatus  10  are possible in which the air-distribution manifold  60  has a different shape from that shown in  FIG. 1  and the core pockets  50  are moved across air-distribution manifold  60  by other means. For instance, the air-distribution manifold  60  may have a flat surface and the core pockets having a flat surface may be slid across the air-distribution manifold  60  by a conveyor system. The core pocket  50  can be described as being in slideable and sealable engagement with the air-distribution manifold  60 . 
         [0033]    Non-fibrous materials can be used in place of the fibers  12  provided that the non-fibrous materials used can be conveyed or directed by the flow of air. Non-fibrous materials can include, but are not limited to, pellets, powders, chunks, and shreds of non-fibrous materials. 
         [0034]    The core pocket  50  can be slightly overfilled. Scarfing roll  80  can be used to scarf excess fibers  12  deposited in the core pocket  50 . A recycle duct  70  can be included in the apparatus  10  to transport excess fibers  12  removed by scarfing. The recycle duct  70  can be configured to transport excess fibers upstream in the process to a recycle distribution chamber  390  which provides a stream of recycled loose air-entrained fibers to be distributed and redeposited in a core pocket  50 . 
         [0035]    A lugged cylinder  90  can also be an element of the apparatus  10 . A plurality of lugs  95  can be disposed about the lugged cylinder  90 . The lugs  95  can compact the mass of fibers  12  deposited in the core pocket  50  to complete formation of the air-laid fibrous article  100 . The formed air-laid fibrous articles  100  can be removed from the apparatus by a takeaway conveyor comprising a vacuum type return roll  115  and a belt  120 . The vacuum type return roll  115  can pull the air-laid fibrous articles  100  from the core pockets  50  as the core pocket  50  rotates past the vacuum type return roll  115 . 
         [0036]    The apparatus  10  can have a single source of fibers  12  in which a stream of air-entrained fibers can be directed towards the core pocket  50 . The apparatus  10  can have a single forming zone  1  in proximity to a single source of fibers  12 , the forming zone being the portion of the apparatus  10  in which fibers  12  are deposited in the core pocket  50  from a single source of fibers. 
         [0037]    The apparatus  10  can further comprise forming zone shields  370 . Forming zone shields  370  can be configured such that as the core pocket  50  moves through the forming zone  1 , the amount of air flow into the core pocket  50  from the surrounding environment is negligible. In other words, the core pocket  50  can be described as being in slideable and sealable engagement with the forming zone shields  370 . Forming zone shields  370  are described more fully herein. 
         [0038]    The core pocket  50 , and the elements thereof, can be considered to have a machine direction MD. The machine direction can be understood to be the direction in which the core pocket  50  travels as air-laid fibrous articles  100  are formed in the core pocket  50 . In the apparatus illustrated in  FIG. 1 , the machine direction would be in line with the direction of rotation of deposition drum  40 . The z direction can be referred to as the direction corresponding with the thickness of the air-laid fibrous article during formation. 
         [0039]    U.S. Pat. No. 4,388,056, issued to Lee et al., U.S. Pat. No. 4,859,388, issued to Peterson and Benson, and U.S. Pat. No. 4,592,708 issued to Feist et al. illustrate apparatus for forming air-laid fibrous webs and absorbent articles. 
         [0040]    An exploded view of an embodiment of a core pocket  50  is shown in  FIG. 2 . The core pocket  50 , and the elements thereof, can be considered to have a machine direction MD, a cross direction CD, and a z direction generally orthogonal to the MD and CD directions. The cross direction is generally orthogonal to the machine direction and generally in plane with the movement of the core pocket  50  as the core pocket  50  travels during formation of air-laid fibrous articles  100 . In the art of air-laid fibrous articles, the z direction can be referred to as the direction corresponding with the thickness of the air-laid fibrous article and the machine direction and cross direction can be considered to be in the plane of the air-laid fibrous article. For an apparatus  10  in which one or more core pockets  50  move circumferentially about air-distribution manifold  60 , the z direction is radially orthogonal to the circumferential path of the core pocket  50 . 
         [0041]    As described herein, the interior facing surfaces or edges are taken to be oriented in a direction away from the discharge chute  30  as the core pocket  50  passes the discharge chute  30 . If an air-distribution manifold  60  is present, interior facing surfaces are oriented towards the air-distribution manifold  60  as the core pocket  50  passes the air-distribution manifold  60 . The exterior facing surface or edges are taken to be oriented in a direction towards the discharge chute  30  as the core pocket  50  passes the discharge chute  30 . 
         [0042]    The core pocket  50  can comprise a shield  130  having an interior facing surface  135  and an exterior facing surface  140  opposing the interior facing surface  135 . The shield  130  can have a shield first end  145  and a shield second end  150  opposing the shield first end  145 . The shield  130  can have a pair of opposing shield lateral side edges  155  each extending from the shield first end  145  to the shield second end  150 . The shield  130  can be a sheet of metal, such as stainless steel, titanium, or other material sufficiently stiff to be used in machinery used in high speed manufacturing operations. As illustrated in  FIG. 2 , the shield  130 , and other components illustrated, can have an arcuate shape in the machine direction for use in an apparatus  10  in which the core pockets  50  are disposed in a circumferential relationship about the periphery of deposition drum  40 , like that shown in  FIG. 1 . The shield  130  and other components of the core pocket  50  can be flat in the machine direction if an air-distribution manifold  60  that is flat in the machine direction is used. By way of example, and not to be limiting, the shield can have a width in the cross direction between the shield lateral side edges  155  between about 60 mm and about 110 mm, a length in the machine direction between about 0.15 and about 0.55 radians, and a thickness in the z direction between about 0.5 mm to about 3 mm. 
         [0043]    The core pocket  50  can further comprise a central opening  160  defined by a void in the shield. By way of example, and not to be limiting, the central opening  160  can be an approximately rectangular shape having rounded corners and have a length of about 109 mm in the machine direction and width of about 22 mm in the cross direction. Other shapes, lengths, and widths can be practical, the defining feature being that the central opening  160  is sized and dimensioned so as to provide for air-flow communication between the central forming chamber  165  and the air-distribution manifold  60 . The length and width of the central opening  160  can be a function of the in-plane geometry of the air-laid fibrous article. 
         [0044]    The term air-flow communication is used herein to describe the relationship between two elements in which air flow can be conveyed between, among, across, along, or through the two elements. 
         [0045]    The core pocket  50  can further comprise a central forming chamber  165 . The central forming chamber  165  can be in air-flow communication with the central opening  160 . The central forming chamber  165  can also have a central forming chamber periphery  170 . The central forming chamber  165  can be sealed to the shield  130  such that airflow passing between the contacting surfaces of the shield  130  and the central forming chamber  165  can be negligible or nonexistent. The central forming chamber  165  can be formed from stainless steel, titanium, or other material suitable for use in high speed manufacturing operations. 
         [0046]    The core pocket  50  can further comprise a plurality of central lateral baffles  175 . The central lateral baffles  175  can be nested within the central forming chamber  165 . The central lateral baffles  175  can span the central forming chamber  165 . That is, the central lateral baffles  175  can extend between the sidewalls  360  of the central forming chamber  165 . The central lateral baffles  175  can be aligned about flush with the interior facing surface  135  of the shield  130 . The central lateral baffles  175  can be formed from sheets of stainless steel, titanium, or other material suitable for use in high speed manufacturing operations. The sheets can be sized and dimensioned to fit within the central forming chamber  165 . The central lateral baffles  175  can be oriented generally orthogonal to the machine direction, as shown in  FIG. 2 . Embodiments in which the central lateral baffles  175  are not oriented generally orthogonal to the machine direction of the core pocket  50  are also contemplated. 
         [0047]    The core pocket  50  can further comprise a central foraminous forming surface  180  in air-flow communication with the central forming chamber  165 . 
         [0048]    As shown in  FIG. 2 , the core pocket  50  can further comprise an edge forming chamber  185  that is disposed about the central forming chamber periphery  170 . The core pocket  50  can further comprise a plurality of edge lateral baffles  190  nested within the edge forming chamber  185 . The edge lateral baffles  190  can span the interior of the edge forming chamber  185 . The edge lateral baffles  190  can span the space between the interior boundaries of the edge forming chamber  185  and the boundaries of the central forming chamber  165 . The edge lateral baffles  190  can be aligned about flush with the interior facing surface  135  of the shield  130 . The edge lateral baffles  190  can be oriented generally orthogonal to the machine direction, as shown in  FIG. 2 . Embodiments in which the edge lateral baffles  190  are not oriented generally orthogonal to the machine direction of the core pocket  50  are also contemplated. The sheets are sized and dimensioned to fit within the edge forming chamber  185 . The edge lateral baffles  190  and central lateral baffles  175  can be formed from sheets of stainless steel, titanium, or other material suitable for use in high speed manufacturing operations. 
         [0049]    The central lateral baffles  175  can be spaced apart from one another in the machine direction by about 0.01 to about 0.04 radians. In one embodiment, the central lateral baffles  175  can be spaced apart from one another in the machine direction by about 18 mm. The edge lateral baffles  190  can be spaced apart from one another in the machine direction by about 0.01 to about 0.04 radians. In one embodiment, the edge lateral baffles  190  can be spaced apart from one another in the machine direction by about 18 mm. The edge lateral baffles  190  and central lateral baffles  175  can have a thickness in the MD direction between about 0.5 mm to about 4 mm. The edge lateral baffles  190  and central lateral baffles  175  can have a height in the z direction between about 10 mm and about 40 mm. These dimensions are provided by way of example and not to be limiting, as other dimensions are practical and are a function of the dimensions of the core pocket  50  and materials from which the core pocket  50  is fabricated. 
         [0050]    The core pocket  50  can further comprise an edge foraminous forming surface  195  in air-flow communication with the edge forming chamber  185 . 
         [0051]    The central foraminous forming surface  180  and the edge foraminous forming surface  195  are highly previous to the flow of air. The central foraminous forming surface  180  and the edge foraminous forming surface  195  can comprise one or more sheets which are permeable to air and have a high percent open area. By way of example, and not to be limiting, the edge foraminous forming surface  195  and central foraminous forming surface  180  can have a percent open area of about 50% percent. The openings in the screen can be about 0.25 mm in diameter. The central foraminous forming surface  180  and the edge foraminous forming surface  195  can be comprised of a thin sheet of stainless steel, titanium, or other material stiff enough to be used in high speed manufacturing operations. The central foraminous forming surface  180  and the edge foraminous forming surface  195  can be comprised of stainless steel, titanium, or other material suitable for use in high speed manufacturing operation having electro etched openings. The central foraminous forming surface  180  and the edge foraminous forming surface  195  can be formed from two or more sheets of foraminous material associated with one another or can be comprised of a single contiguous sheet of foraminous material. WO2001042549A1, filed Dec. 8, 2000 and WO2000029656A1, filed Nov. 17, 1999 describe an embodiment of foraminous forming surfaces. 
         [0052]    The edge lateral baffles  190  can span the space between the plane defined by the interior facing surface  135  of the shield  130 , which can be flat or curved, and the interior facing surface of the edge foraminous forming surface  195 . The central lateral baffles  175  can span the space between a plane defined by the interior facing surface  135  of shield  130  and the interior facing surface of the central foraminous forming surface  180 . 
         [0053]    The core pocket  50  can optionally comprise a central support mesh  201  adjacent the central foraminous forming surface  180 . The core pocket  50  can also optionally comprise an edge support mesh  202  adjacent the edge foraminous forming surface  195 . The central support mesh  201  can extend between the central foraminous forming surface  180  and the central lateral baffles  175 . The edge support mesh  202  can extend between the edge foraminous forming surface  195  and the edge lateral baffles  190 . 
         [0054]    The core pocket  50  can optionally comprise a peripheral edge template  350  having a void  355  in the shape of the air-laid fibrous article to be formed. The peripheral edge template  350  can be a separate element attached to the edge forming chamber  185  or can be integral with edge forming chamber  185 , such that the edge forming chamber  185  and peripheral edge template  350  are comprised of a unitary material. The peripheral edge template  350  can be positioned adjacent the exterior surface of edge foraminous forming surface  195  in an overlying relationship. 
         [0055]    The peripheral edge template  350  can comprise a sheet of material suitable for use in high speed manufacturing operations. The thickness of the peripheral edge template can be selected to correspond with the desired thickness of the air-laid fibrous article  100  in the z direction or a thickness such that the air-laid fibrous article  100  is the proper thickness for further downstream processing. The boundaries of the peripheral edge template  350  can be selected to correspond with the desired shape of the air-laid fibrous article  100  in the MD-CD plane of the air-laid fibrous article  100  or the proper shape for further downstream processing. The term downstream can be understood as the direction of processing from the start of manufacturing the absorbent article towards the end of manufacturing. The term upstream can be understood as the direction in processing opposite downstream. 
         [0056]    A plan view of one embodiment of core pocket  50  in which the interior facing surface  135  of the shield  130  is presented to the viewer is shown in  FIG. 3 . As shown in  FIG. 3 , the core pocket  50  comprises a pair of edge openings  210 . The edge openings  210  extend along each side of the shield  130  in the machine direction and extend laterally in the cross direction beyond the shield lateral side edges  155 . The edge openings  210  are defined by the spaces between the shield lateral side edges  155  and the edges of the edge forming chamber  185 . The edge forming chamber  185  can be in air-flow communication with the edge openings  210 . The edge openings  210  can extend from the shield first end  145  to the shield second end  150 . The shield  130  can be generally rectangular. Other shapes of the shield  130  are also possible. 
         [0057]    By way of example, and not to be limiting, each edge opening  210  can have a width in the cross direction between about 10 mm and about 60 mm. 
         [0058]    The core pocket  50  can be configured such that different air pressures can be applied to the central foraminous forming surface  180  and the edge foraminous forming surface  195 . Ambient air pressure, positive air pressure, and negative air pressure can be useful in forming air-laid fibrous articles. In describing positive, ambient and negative air pressures, as used herein, the origin dividing positive pressure and negative pressure is atmospheric pressure (approximately 101.325 kPa), with positive pressures defined as being greater than one atmosphere, ambient pressure being atmospheric pressure, and negative pressures being less than one atmosphere. Particular magnitudes of pressure reported herein are absolute pressures. 
         [0059]    In the embodiment shown in  FIG. 3 , air pressure applied to the central opening  160  can be transmitted through the central opening  160 , between the central lateral baffles  175  and into the central forming chamber  165 . Air pressure in the central forming chamber  165  can be applied to the central foraminous forming surface  180 . If a central support mesh  201  is present, air pressure can be transmitted though the central support mesh  201  to the central foraminous forming surface  180 . The wall or walls of the central forming chamber  165  can be made of material impervious to air-flow and joined to one another by seals, seams, welds, or connections that are also impervious to air-flow. Thus, the central forming chamber  165  and edge forming chamber  185  can be isolated from one another in that the air pressure in the central forming chamber  165  can be different than the air pressure in the edge forming chamber  185  and air-flow between the central forming chamber  165  and the edge forming chamber  185  can be small enough to be negligible or even nonexistent. Thus, the edge foraminous forming surface  195  can have a pressure applied thereto that is independent of the pressure applied to the central foraminous forming surface  180  and the pressures applied to the edge foraminous forming surface  195  and the central foraminous forming surface  180  can be independently controlled. 
         [0060]    In the embodiment shown in  FIG. 3 , air pressure applied to the edge openings  210  can be transmitted through the edge openings  210 , between the edge lateral baffles  190  into the edge forming chamber  185 . With or without the edge lateral baffles, air pressure applied to the edge openings  210  can be transmitted throughout the edge forming chamber  185  such that the pressure applied to the edge openings  210  is also applied to the portions of the edge forming chamber  185  overlying the shield  130 . Thus, an “island” of one pressure can be applied to the central foraminous forming surface  180  that is surrounded by a “ring” of another pressure. In effect, pressure applied to the edge forming chamber  185  is bridged across the shield  130 . 
         [0061]    Air pressure in the edge forming chamber  185  can be applied to the edge foraminous forming surface  195 . If edge support mesh  202  is present, air pressure can be transmitted through the edge support mesh  202  to the edge foraminous forming surface  195 . 
         [0062]    If a central support mesh  201  is present, the central support mesh  201  can be joined to the edges of the central forming chamber  165 , as shown in  FIG. 4 . The central support mesh  201  can provide support to the central foraminous forming surface  180  by distributing load applied to the central foraminous forming surface  180  to the boundaries of the central forming chamber  165  and/or to the central lateral baffles  175 , which can reduce deformation of the central foraminous forming surface  180 . As shown in  FIG. 4 , the central support mesh  201  can be inset into the central forming chamber  165  such that central support mesh  201  is about flush with the exterior edge of the central forming chamber  165  that is oriented away from the exterior facing surface  140  of shield  130 . 
         [0063]    Similarly, if edge support mesh  202  is present, the edge support mesh  202  can be joined to the boundaries of the edge forming chamber  185  and the boundaries of the central forming chamber  165 . The edge support mesh  202  can provide support to the edge foraminous forming surface  195  in the same manner as the central support mesh  201 . The edge support mesh  202  can be inset into the edge forming chamber  185  such that edge support mesh  202  is about flush with the exterior edge of the edge forming chamber  185  that is oriented away from the exterior facing surface  140  of shield  130 . In this arrangement, the central forming chamber  165  can be described as projecting through the central support mesh  201  and the edge support mesh  202 . In this arrangement, air flow between the central forming chamber  165  and the edge forming chamber  185  can be small enough to be negligible or even non-existent and the air pressure in the central forming chamber  165  can be different from the air pressure in the edge forming chamber  185 . Without being bound by theory, it is thought that by delivering different pressures to the edge forming chamber  185  and central forming chamber  165 , the amount of scarfing needed to form a fibrous article having one surface that is contoured in the z-direction and another surface that is flat can be reduced. 
         [0064]    The central support mesh  201  can extend between the central foraminous forming surface  180  and the central lateral baffles  175  and can be in contact with the central foraminous forming surface  180  and the central lateral baffles  175 , if present. In this configuration, the central support mesh  201 , which can be a structure having a plurality of open spaces, can fill all the space between the central foraminous forming surface  180  and the central lateral baffles  175  if present. 
         [0065]    The edge support mesh  202  can extend between the edge foraminous forming surface  195  and the edge lateral baffles  190  and can be in contact with both the edge foraminous forming surface  195  and the edge lateral baffles  190 , if present. In this configuration, the edge support mesh  202 , which can be a structure having a plurality of open spaces, can fill all the space between the edge foraminous forming surface  195  and the edge lateral baffles  190  if present. 
         [0066]    The central support mesh  201  and edge support mesh  202  can be comprised of stainless steel, titanium, or other material suitable for use in high speed manufacturing operations. Support mesh can be a product described as honeycomb disclosed in WO2001042549A1, filed Dec. 8, 2000 and WO2000029656A1, filed Nov. 17, 1999, or WO2001098574A2, filed Jun. 19, 2001. The central support mesh  201  and edge support mesh  202  can have a high percent open area permitting air flow without significant resistance. The central support mesh  201  and edge support mesh  202  can have a plurality of open spaces. The central support mesh  201  and the edge support mesh  202  can be a web of sheet metal comprised of strips of corrugated sheet metal joined to one another at the bending axes of the corrugations. 
         [0067]    As shown in  FIG. 4 , central support mesh  201  and edge support mesh  202  can be comprised of mesh walls  215  and mesh cells  220 . Portions of the mesh walls  215  can be coordinated to be in alignment with the edges of central lateral baffles  175 , thereby substantially preventing movement of air in the machine direction of central forming chamber  165 . Portions of the mesh walls  215  can be coordinated to be in alignment with and sealed to the central lateral baffles  175 , thereby substantially preventing movement of air in the machine direction of central forming chamber  165 . 
         [0068]    The edge support mesh  202  can be configured with respect to the edge foraminous forming surface  195  and the edge lateral baffles  190  in the same manner as the central support mesh  201  can be configured with respect to the central foraminous forming surface  180  and the central lateral baffles  175 . Portions of the mesh walls  215  can be coordinated to be in alignment with the edges of edge lateral baffles  190 , thereby substantially preventing movement of air in the machine direction of edge forming chamber  185 . Portions of the mesh walls  215  can be coordinated to be in alignment with and sealed to the edge lateral baffles  190 , thereby substantially preventing movement of air in the machine direction of edge forming chamber  185 . 
         [0069]    The mesh walls of the central support mesh  201  and the edge support mesh  202  need not be in alignment with or sealed to the central lateral baffles  175  and edge lateral baffles  190 . In general, small mesh cells  220  can sufficiently resist air flow in the machine direction of the core pocket. By way of example, and not to be limiting, mesh cells  220  having approximately rectangular openings about 13 mm by about 5 mm, in a staggered relationship, such as a running or stretcher bond brick pattern, can be used to sufficiently reduce air flow in the machine direction of the core pocket  50 . By way of example, and not to be limiting, the central support mesh  201  and edge support mesh  202  can be comprised of material having a thickness of about 0.2 mm. Without being bound by theory, it is thought that the tortuous pathway for air flow through the spaces between the central support mesh  201  and central lateral baffles  175  and the spaces between the edge support mesh  202  and the edge lateral baffles  190  can offer sufficient resistance to air flow in the machine direction of the core pocket  50 . 
         [0070]    In one embodiment of the core pocket  50 , central foraminous forming surface  180  can have a recessed portion relative to the edge foraminous forming surface  195 . Non-limiting examples for the shape of the recess can include a frustum, a frustum having an oval shaped base, a frustum having an irregularly shaped base and top, and a pyramidal frustum. As shown in  FIG. 5 , the central foraminous forming surface  180  and edge foraminous forming surface  195  can be considered to a have a machine direction MD and a cross direction CD. The recessed portion  225  can be generally characterized by the angles formed by the recess in the machine direction and cross direction. The angle of the recess in the machine direction a can be between about 0° and about 90°, with 0° corresponding to an arrangement in which the central foraminous forming surface  180  is not recessed relative to the edge foraminous forming surface  195 . The angle of the recess in the machine direction α can be between about 1° and about 45°. The angle of the recess in the cross direction β can be between about 0° and about 90°, with 0° corresponding to an arrangement in which the central foraminous forming surface  180  is not recessed relative to the edge foraminous forming surface  195 . The angle of the recess in the cross direction β can be between about 1° and about 70°. The specific ranges for angles α and β are provided by way of example and not to be limiting. The angles α and β can be the same or different and the angle on one side of the recess can be different from the angle on the opposing side. The recess walls  230  can be straight or curved, combinations of straight sections, combinations of curved sections, or combinations of straight and curved sections. The configurations for the recessed portion  225  described herein are by way of example only and not to be limiting as other configurations are possible. The central foraminous forming surface  180  and the edge foraminous forming surface  195  can be in plane with one another so as to be considered flat with respect to one another. 
         [0071]    By way of example, and not to be limiting, the edge foraminous forming surface  195  and the central foraminous forming surface  180 , upon which fibers are deposited, can have the shape of a core of a sanitary napkin, diaper, incontinent pad, or other absorbent article designed to be worn in the crotch of the wearer. A perspective cut-away view illustrating an edge foraminous forming surface  195  and a central foraminous forming surface  180 , upon which fibers are deposited, having the shape of a core for sanitary napkin is shown in  FIG. 5 . To provide for a well defined periphery and thickness of the air-laid fibrous article  100 , the central foraminous forming surface  180  and the edge foraminous forming surface  195  can be recessed relative to the boundaries of the edge forming chamber  185 , as shown in  FIG. 5 , or recessed relative to a peripheral edge template  350 , as shown in  FIG. 6 . 
         [0072]    As discussed previously, the core pocket  50  can optionally comprise a peripheral edge template  350  that can provide for a well defined periphery and thickness of the air-laid fibrous article  100 . By overlaying a peripheral edge template  350  over the foraminous forming surfaces, the foraminous forming surfaces can be recessed relative to the exterior facing surface of the core pocket  50  which is the side of the core pocket  50  oriented away from the shield  130 . 
         [0073]    By way of example, and not to be limiting, the peripheral edge template  350  can have the shape of a core of a sanitary napkin, diaper, incontinent pad, or other absorbent article designed to be worn in the crotch of the wearer. 
         [0074]    The core pocket  50  can comprise one or more central forming chambers  165  disposed in a single edge forming chamber  185 , as shown in  FIG. 7 .  FIG. 7  is a cross sectional view of a core pocket  50  mounted on deposition drum  40  as viewed from the opposite side as the view provided in  FIG. 1 . In the embodiment shown in  FIG. 7 , the core pocket  50  has a plurality of central forming chambers  165  within a single edge forming chamber  185 . In this configuration, a web of air-laid fibrous material in which a plurality of zones of material deposited above the central forming chambers can be formed with the apparatus  10 . A single edge forming chamber  185  can extend circumferentially about deposition drum  40 . 
         [0075]    In apparatus  10  in which the core pockets  50  are disposed in a circumferential relationship about the periphery of deposition drum  40 , all of the components of the core pocket  50  can have an arcuate shape in the machine direction. By way of example, and not to be limiting, a core pocket  50  having an arcuate shape in the machine direction can have a length as measured in the machine direction between about 0.15 and about 0.55 radians. By way of example, and not to be limiting, the central opening  160  for a core pocket  50  having an arcuate shape in the machine direction can have a length as measured in the machine direction between about 0.1 and about 0.4 radians. 
         [0076]    In apparatus  10 , in which the core pockets are not disposed about the periphery of a deposition drum  40  but travel in a flat plane as air-laid fibrous articles  100  are formed, the core pocket  50 , and the components thereof, can have a flat shape in the machine direction. 
         [0077]    An embodiment of apparatus  10  further comprising an air-distribution manifold  60  operatively related to the core pocket  50  is shown in  FIG. 1 . By operatively related it is meant that the air-distribution manifold  60  is positioned such that the core pocket  50  can slide along the air-distribution manifold  60 . In one embodiment, the air-distribution manifold  60  can have a curved air-distribution surface. Air-distribution manifold  60  can be stationary. In the embodiment shown in  FIG. 1 , the core pocket  50  can slide along the air-distribution manifold  60  as the deposition drum  40  rotates. In this embodiment, the core pocket  50  can be disposed in a circumferential relationship about the periphery of deposition drum  40 . The shield  130 , central forming chamber  165 , and edge forming chamber  185  can have an arcuate shape in the machine direction that generally conforms to the curved peripheral surface of the air-distribution manifold  60 . The radius of curvature of the shield  130 , central forming chamber  165 , and edge forming chamber  185  can be about the same or slightly greater than the curvature of the air-distribution surface of the air-distribution manifold  60 . Furthermore, by operatively related, it is meant that the air-distribution manifold  60  can be in air-flow communication with one or more core pockets  50  as the deposition drum  40  rotates about the air-distribution manifold  60  such that controlled magnitudes of air pressure can be applied to portions of the core pocket  50 . For example, the air pressure applied by the air-distribution manifold  60  to the central forming chamber  165  can differ from the air pressure applied to the edge forming chamber  185 . 
         [0078]    As shown in  FIG. 8 , the air-distribution manifold  60  can comprise a central zone  240 . The central zone  240  can have a central zone first end  245  and a central zone second end  250  opposing the central zone first end  245 . The central zone  240  can have a pair of opposing central zone lateral side edges  255  extending from the central zone first end  245  to the central zone second end  250 . The air-distribution manifold  60  can further comprise a pair of edge zones  260 . The edge zones  260  can be adjacent to the central zone lateral side edges  255 . 
         [0079]    Without being bound by theory it is thought that by having the edge zones  260  adjacent the central zone lateral side edges  255  and forming the air-laid fibrous article  100  from a single stream of air-entrained fibers that certain beneficial results can occur. For instance, it is thought that air-laid fibrous articles  100  formed in this manner have a more coherent mechanical structure than if one stream of air-entrained fibers  12  is used to deposit fibers on the edge foraminous forming surface  195  and another stream of air-entrained fibers is used to deposit fibers on the central foraminous forming surface  180 . 
         [0080]    In describing the central zone  240  as having a central zone first end  245 , the central zone first end  245  is the end of the central zone  240  which the core pocket  50  first encounters as the core pocket  50  reaches the location in the apparatus where air-entrained fibers are directed to the core pocket  50 . The central zone second end  250  is the end of the central zone  240  which the core pocket  50  encounters as the core pocket  50  slides along the air-distribution manifold  60  after the core pocket  50  has passed the central zone first end  245 . 
         [0081]    The central zone  240  and the edge zones  260  are not in air-flow communication with one another as the core pocket  50  slides along the zones of the air-distribution manifold  60 . That is, the air pressure in the central zone  240  can be maintained at a pressure that differs from the air pressure in the edge zones  260  and the air-flow between the central zone  240  and the edge zones  260  can be small enough to be to be negligible. The air pressure in the central zone  240  and edge zones  260  can be controlled independently. To reduce the amount of air-flow between the central zone  240  and the edge zones  260  when the core pocket  50  is overlying these zones, a sealing material, such as felt, can be affixed along the boundaries between the central zone  240  and the edge zones  260 . To further reduce the amount of air-flow between the central zone  240  and the edge zones  260  when the core pocket  50  is overlying these zones, a sealing material, such as Multifill Bearing Tape having a width of about 1 cm and a thickness of about 0.8 mm supplied by Garlock Bearings, LLC, can be affixed to the interior facing surface  135  of the shield  130  such that the sealing material is approximately coincident with the boundaries between the central zone  240  and the edge zones  260  of the air-distribution manifold  60  and aligned in the machine direction of the core pocket  50 . 
         [0082]    As shown in  FIG. 8 , each edge zone  260  can have an edge zone first end  265 . The edge zone first end  265  can be aligned with the central zone first end  245 . The edge zone first end  265  does not have to be aligned with the central zone first end  245 . Each edge zone  260  can further have an edge zone second end  270  opposing the edge zone first end  265 . The edge zone second end  270  can be aligned with the central zone second end  250 . The edge zone second end  270  does not have to be aligned with the central zone second end  250 . Furthermore, the edge zones  260  need not have the same geometry as one another. Each edge zone  260  need not have the same length, as measured in the machine direction, as another edge zone  260 . 
         [0083]    The air-distribution manifold  60  can further comprise a central recycle zone  275 , as shown in  FIG. 8 . The central recycle zone  275  can have a central recycle zone first end  280 , a central recycle zone second end  285  opposing the central recycle zone first end  280 , and a pair of opposing central recycle zone lateral side edges  290  extending from the central recycle zone first end  280  to the central recycle zone second end  285 . The central recycle zone first end  280  can be adjacent the central zone second end  250 , as shown in  FIG. 8 . The central recycle zone first end  280  can be located some distance away from the central zone second end  250 . As in the embodiment shown in  FIG. 8 , the edge zone second ends  270  can be aligned with the central recycle zone second end  285 . The central recycle zone  275  can have a width that is the same as the width of the central zone  240 . 
         [0084]    The air-distribution manifold  60  can further comprise a central scarfing zone  295 . The central scarfing zone  295  can have a central scarfing zone first end  300  and a central scarfing zone second end  305  opposing the central scarfing zone first end  300 . The central scarfing zone  295  also can have a pair of opposing central scarfing zone lateral side edges  310 , each of which can extend from the central scarfing zone first end  300  to the central scarfing zone second end  305 . The central scarfing zone first end  300  can be adjacent the central recycle zone second end  285 . The central scarfing zone  295  can have a width that is the same as the width of the central zone  240 . 
         [0085]    As shown in  FIG. 8 , the air-distribution manifold  60  can further comprise a pair of edge scarfing zones  315  adjacent the central scarfing zone lateral side edges  310 . Each edge scarfing zone  315  has an edge scarfing zone first end  320  and an edge scarfing zone second end  325  opposing the edge scarfing zone first end  320 . The edge scarfing zone first end  320  can be aligned with the central scarfing zone first end  300 . The edge scarfing zone second end  325  can be aligned with the central scarfing zone second end  305 . The pressure applied at the central scarfing zone  295  can be about 12 kPa. The pressure applied at the central scarfing zone  295  can be between about 2 kPa and about 20 kPa. These pressures are provided by way of example and are not to be limiting. The edge scarfing zones  315  can each have the same width as edge zones  260 . 
         [0086]    The air-distribution manifold  60  can also comprise a hold down zone  330 . The hold down zone  330  can be disposed adjacent the central zone second end  250 , if central scarfing zone  295  and central recycles zone  275  are not present. The hold down zone  330  can be disposed adjacent the central recycle zone second end  285 . As shown in  FIG. 8 , the hold down zone  330  can be disposed adjacent the central scarfing zone  295 . The hold down zone  330  can be disposed adjacent the central scarfing zone second end  305 . The pressure applied at the hold down zone  330  can be about 4 kPa. The pressure applied at the hold down zone  330  can be between about 1 kPa and about 10 kPa. These pressures are provided by way of example and not to be limiting. 
         [0087]    The central zone  240  has a central zone width in the cross direction defined by the shortest distance between the central zone lateral side edges  255 . The central zone width can be between about 15 mm and about 50 mm. The central zone  240  can have a width of about 31 mm. The length of the central zone  240 , as measured in the machine direction can be about 195 mm. Each edge zone  260  also has an edge zone width in the cross direction. The edge zone width can be between about 5 mm and bout 40 mm. The edge zone width can be about 12 mm. The length of each edge zone  260 , as measured in the machine direction, can be about 363.5 mm. The central recycle zone width can be about the same as the central zone width. The central scarfing zone  295  can have a central scarfing zone width defined by the shortest distance between the central scarfing zone lateral side edges  310 . The central scarfing zone width can be about the same as the central zone width. Each edge scarfing zone width can be about the same as each edge zone width. The edge scarfing zone length, as measured in the machine direction, can be about 104.5 mm. The hold down zone  330  has a hold down zone width in the cross direction. The hold down zone width can be between about 30 mm and about 90 mm. The hold down zone width can be about 60 mm. The hold down zone width can be about the same as the sum of the central zone width and each edge zone width. The length of the hold down zone, as measured in the machine direction, can be about 104.5 mm. The central zone widths, edge zone widths, central recycle zone width, central scarfing zone width, edge scarfing zone width, and hold down zone width provided herein are by way of example and not to be limiting given that these dimensions are ultimately governed by the desired geometry of air-laid fibrous article  100 , the dimensions of the core pocket  50 , and the geometry of the air-distribution manifold  60 . For an air-distribution manifold  60  having a curved air-distribution surface  262 , the lengths reported are lengths about the circumference of the air-distribution manifold  60 . 
         [0088]    As with the boundary between the central zone  240  and edge zone  260 , sealing materials can be applied between the boundaries of the different zones of the air-distribution manifold  60 . 
         [0089]    The central zone  240  is in air-flow communication with a source of air pressure. The air pressure in the central zone can be negative. Some people skilled in the art refer to negative pressure as vacuum or vacuum pressure. Similarly, each edge zone  260  is in air-flow communication with a source of air pressure. The air-distribution manifold  60  can be operatively related to one or more core pockets  50  such that as a core pocket  50  slides along the air-distribution manifold  60 , the central zone  240  of the air-distribution manifold  60  can be in air-flow communication with the central opening  160  in the shield  130 . Furthermore, the air-distribution manifold  60  can be operatively related to one or more core pockets  50  such that as the core pocket  50  slides along the air-distribution manifold  60 , the edge zones  260  can be in air-flow communication with the edge openings  210  of the core pocket  50 . 
         [0090]    The pressure applied at the edge zones  260  can differ from the pressure applied at the central zone  240 . The pressure applied at the central zone  240  and the edge zones  260  can be between about 6.7 kPa and about 16 kPa. The pressure applied at the central zone  240  and the edge zones  260  can be between about 2 kPa and about 20 kPa. These pressures are by way of example only and are not to be limiting, as other pressures can be applied at the central zone  240  and edge zones  260  with the result that air-laid fibrous articles having different properties can be formed. 
         [0091]    The air-distribution manifold  60  illustrated in  FIG. 8  has a curved air-distribution surface  262 . The air-distribution surface  262  is the portion of the air-distribution manifold  60  facing the core pocket  50  as the core pocket  50  slides over the air-distribution manifold  60 . The shield  130 , central forming chamber  165 , and edge forming chamber  185  can have an arcuate shape in the machine direction that generally conforms to the air-distribution surface  262 . The air-distribution manifold  60  can have a flat air-distribution surface  262 . 
         [0092]    For an air-distribution manifold  60  having a curved air-distribution surface  262 , the central zone  240  can extend between about 0.5 radians and about 0.7 radians. If present, the edge zones  260  can extend between about 0.5 radians and about 1.4 radians. If present, the central recycle zone  275  can extend between about 0.5 and about 0.7 radians. If present, the central scarfing zone  295  and edge scarfing zones  315  can extend between about 0.2 radians and about 0.4 radians. The hold down zone  330 , if present, can extend between about 0.5 radians and about 0.8 radians. The dimensions for the central zone  240 , edge zones  260 , central recycle zone  275 , central scarfing zone  295 , edge scarfing zones  315 , and hold down zone  330  are provided by way of example and not to be limiting. Other dimensions for the central zone  240 , edge zones  260 , central recycle zone  275 , central scarfing zone  295 , edge scarfing zones  315 , and hold down zone  330  are possible. 
         [0093]    A cutaway view of one embodiment of the air-distribution manifold  60  is shown in  FIG. 9 . As shown in  FIG. 9 , air pressure can be conducted or conveyed through ducts within the air-distribution manifold  60  to various portions of the air-distribution surface  262 . As known by those skilled in the art, there are many possible designs that are suitable for conducting pressures to different portions of an air-distribution manifold. 
         [0094]    In one embodiment of apparatus  10  in which the air-distribution manifold  60  has a curved air-distribution surface  262 , the core pocket  50  can slide along the air-distribution manifold at an angular velocity of between about 2 radians per second and about 10 radians per second. The core pocket  50  can slide along the air-distribution manifold at an angular velocity of about 7.2 radians per second. The range and particular values for angular velocity for the core pocket  50  are provided by way of example and not to be limiting as other values for the angular velocity of the core pocket  50  are possible. 
         [0095]    An illustration of one embodiment in which the air-distribution manifold  60  is in operative relationship with a portion of a core pocket  50  is shown in  FIG. 10 . The central zone  240 , shield  130 , and central opening  160  are sized and dimensioned so that air pressure in the central zone  240  can be transmitted to the central forming chamber  165 , but not to the edge forming chamber  185 . Similarly, each edge zone  260  of the air-distribution manifold  60  can be in air-flow communication with each edge opening  210  and thereby the edge forming chamber  185 . Each edge zone  260  and each edge opening  210  is sized and dimensioned so that air pressure in the edge zones  260  is transmitted to the edge forming chamber  185 , but not to the central forming chamber  165 . By operatively relating the core pocket  50  and air-distribution manifold in this manner, the pressure applied to the central foraminous forming surface  180  can be independently controlled and differ from the pressure applied to the edge foraminous forming surface  195 . 
         [0096]    By applying different pressures to the central foraminous forming surface  180  and the edge foraminous forming surface  195 , fibrous articles having a basis weight that varies in the machine direction and cross direction can be formed. For instance, if the central foraminous forming surface  180  is acted upon by a negative pressure, air-entrained fibers discharged from discharge chute  30  are drawn to the central foraminous forming surface. The velocity of air-entrained particles can be a function of the characteristics of the hammermill  20 , the shape of the discharge chute  30 , these features combining to affect the momentum of air-entrained fibers exiting the discharge chute in the absence of a negative pressure, and the pressure on either of the foraminous forming surfaces. If the pressure on the central foraminous forming surface  180  is less than the pressure on the edge foraminous forming surface  195 , the momentum of the air-entrained fibers as they are directed towards the foraminous forming surfaces can be greater for fibers directed towards the central foraminous forming surface  180  than for fibers directed towards the edge foraminous forming surface  195 . The basis weight of fibers deposited on the foraminous forming screens can be a function of the momentum of the fibers as the fibers are deposited, with higher basis weights occurring as a result of greater momentum. Thus, if the pressure on the central foraminous forming surface  180  is less than the pressure on the edge foraminous forming surface  195 , the basis weight of the fibers deposited on the central foraminous forming surface  180  can be greater than the basis weight of the fibers deposited on the edge foraminous forming surface  195 . 
         [0097]    One skilled in the art can appreciate that different combinations of pressure acting on the foraminous forming surfaces can yield fibrous articles having different characteristics. For instance, if the difference in the pressure on the central foraminous forming surface  180  and the edge foraminous forming surface  195  is large, the contrast in basis weight of the fibrous article in the machine direction and cross direction can be large. If the pressure on the edge foraminous forming surface  195  is less than the pressure on the central foraminous forming surface  180 , the basis weight of the fibrous article can be greater in portions of the fibrous article deposited on the edge foraminous forming surface  195  than in portions deposited on the central foraminous forming surface  180 . 
         [0098]    If the central foraminous forming surface  180  is recessed relative to the edge foraminous forming surface  195 , the pressures applied to the central foraminous forming surface  180  and the edge foraminous forming surface  195  can be set at a magnitudes such that, as the core pocket moves towards the central scarfing zone  295  and edge scarfing zones  315 , the level of the fibrous material overlying the edge foraminous forming surface  195  and the level of the fibrous material overlying the central foraminous forming surface  180  are about the same. Setting the pressures in this manner can reduce the amount of scarfing necessary to create an air-laid fibrous article  100  having a flat surface. 
         [0099]    The pressure on either of the foraminous forming surfaces can be ambient. For fibers deposited on a foraminous forming surface upon which the pressure is ambient, the velocity of the fibers deposited on that surface can be substantially a function of the characteristics of the hammermill  20  and discharge chute  30 . 
         [0100]    In one embodiment, the pressure on the central foraminous forming surface  180  can be negative and the pressure on the edge foraminous forming surface  195  can be ambient. In this embodiment, negative pressure on the central foraminous forming surface  180  can draw air out from the edge zones  260 , through the edge forming chamber  185 , and through the edge foraminous forming surface  195  towards the central foraminous forming surface  180 . In this configuration, air flow emanating from the edge foraminous forming surface  195  can assist in directing fibers  12  towards the central foraminous forming surface  180  and/or substantially reduce the amount of fibers  12  deposited on the edge foraminous forming surface  195 . Negative pressure on the edge foraminous forming surface  195  and ambient pressure on the central foraminous forming surface  180  can employed similarly to assist in directing fibers  12  towards the edge foraminous forming surface  195  and/or substantially reducing the amount of fibers  12  deposited on the central foraminous forming surface  180 . 
         [0101]    The pressure on both the central foraminous forming surface  180  and the edge foraminous forming surface  195  can be negative. The pressure on the central foraminous forming surface  180  can be approximately the same as the pressure on the edge foraminous forming surface  195 . 
         [0102]    Central lateral baffles  175  can also be in slideable and sealable engagement with central zone  240 . The central lateral baffles  175  divide the central forming chamber  165  into a plurality of central forming chamber lateral sections that are not in free air-flow communication with one another. Thus, the central lateral baffles  175  substantially reduce or prevent the movement of air in the machine direction through the central forming chamber  165 . 
         [0103]    Similarly, the edge lateral baffles  190  can be in slideable and sealable engagement with the edge zones  260 . The edge lateral baffles  190  divide the edge forming chamber  185  into a plurality of edge forming chamber lateral sections that are not in free air-flow communication with one another. By this structure, movement of air in the machine direction through the edge forming chamber  185  can be substantially reduced or prevented. 
         [0104]    Reducing movement of air in the machine direction of the core pocket may be desired because as the core pocket  50  slides along the air-distribution manifold  60 , different portions of the core pocket  50  may be in air-flow communication with different zones of the air-distribution manifold  60 . For instance, as the core pocket  50  moves in the machine direction during formation of the core, when the core pocket  50  is at a particular location, half of the edge openings  210  may be in air-flow communication with the edge zones  260  and the other half of the edge openings  210  may be in air-flow communication with the edge scarfing zones  315 . Without edge lateral baffles  190 , the air pressure acting on the edge forming chamber  185  would be approximately the resultant of the air pressures applied at the edge zones  260  and the edge scarfing zones  315 . This would result in variations of the air pressure applied to portions of the edge foraminous forming surface  195  not corresponding to the location of the different portions of the edge foraminous forming surface  195  relative to the zones on an air-distribution manifold  60  comprising multiple zones. The net result on an air-laid fibrous article would be a gradual variation in the basis weight of the fibrous article in the machine direction, which may be undesirable. Central lateral baffles  175  can perform in the same manner. 
         [0105]    An embodiment of an air-distribution manifold  60  having a flat air-distribution surface  262  is shown in  FIG. 11 . For an air-distribution manifold  60  having a flat air-distribution surface  262 , the shield  130 , central forming chamber  165 , and edge forming chamber  185  also can have a flat shape that generally conforms to the flat air-distribution surface  262 . An approach to operatively relating a core pocket to a flat air-distribution manifold is illustrated in U.S. Pat. No. 3,973,291 issued to Kolbach, Aug. 10, 1976. 
         [0106]    The apparatus  10  can further comprise a scarfing roll  80  positioned in operative relationship with the core pocket  50 . The scarfing roll  80  can be positioned so that as the core pocket  50  slides along the air-distribution manifold  60  excess fibrous material deposited on the central foraminous forming surface  180  or the edge foraminous forming surface  195  can be scraped away. If excess fibrous material is deposited on the central foraminous forming surface  180  or the edge foraminous forming surface  195 , the scarfing roll  80  contacts the outwardly facing free surface of the fibrous article. The scarfing roll  80  can be positioned such that scarfing roll  80  can contact the outwardly facing free surface of the fibrous article without contacting the core pocket  50 . 
         [0107]    Scarfing roll  80  can be a roll of blades rotating about a shaft, as is known in the art. The movement of the peripheral surface of scarfing roll  80  can remove uneven portions from the free surface of the air-laid fibrous article to produce a more uniform and level surface. The surface of the scarfing roll  80  can be adjusted to provide a desired contour along the scarfed surface of the fibrous article. The scarfing roll  80  can be disposed in a spaced adjacent relationship to the central foraminous forming surface  180  and the edge foraminous forming surface  195  as these surfaces move past the scarfing roll  80 . 
         [0108]    Scarfing roll  80  can rotate in a direction such that the peripheral surface of the scarfing roll  80  moves counter to the direction the fibrous article moves by the scarfing roll  80 . 
         [0109]    The apparatus  10  can further comprise a recycle duct  70 . As shown in  FIG. 12 , the recycle duct  70  can have a recycle duct entrance  340  and a recycle duct exit  345 . The recycle duct entrance  340  can be positioned in operative relationship with the scarfing roll  80 . The recycle duct exit  345  can be positioned in operative relationship with the central recycle zone  275  and adjacent edge zones  260  of the air-distribution manifold  60 , if present. The recycle duct exit  345  can be connected to a recycle distribution chamber  390 . The recycle distribution chamber  390  can be positioned in operative relationship with the central recycle zone  275  and edge zones  260  adjacent the central recycle zone  275  of the air-distribution manifold  60  as the core pocket  50  passes between the air-distribution manifold  60  and the recycle duct exit  345 . The recycle distribution chamber  390  can provide space in which the fibers  12  passing through the recycle duct  70  can be redistributed over the core pocket  50  when the core pocket  50  is in air-flow communication with the central recycle zone  275  and the edge zones  260  adjacent the central recycle zone  275 . A portion of the recycled loose air-entrained fibers  12  discharged in the recycle distribution chamber  390  can be redeposited on the central foraminous forming surface  180  and another portion of the recycled loose air-entrained fibers  12  discharged in the recycle distribution chamber  390  can be redeposited on the edge foraminous forming surface  195 . 
         [0110]    Recycle duct  70  can be a tube of any shape that can convey air-entrained fibrous material. Recycle duct  70  can be a tube having a cross sectional area that decreases between the recycle duct entrance  340  and the recycle duct exit  345  designed to convey recycled fibers  12  at a velocity between about 5 m/s and about 10 m/s. Recycle duct entrance  340  can be placed proximal the scarfing roll  80  such that fibrous material scarfed from the article can be gathered into or directed to the recycle duct entrance  340  and conveyed towards the central recycle zone  275  and the portion of the edge zones  260  adjacent the central recycle zone  275 . Fibrous material can be conveyed in the recycle duct  70  by air. The air pressure on the central recycle zone  275  and edge zones  260  adjacent the central recycle zone  275  can be lower than the pressure on the central scarfing zone  295  and the edge scarfing zones  315 . The difference in pressure between these two zones creates a pressure differential across the recycle duct  70  in which the pressure at the recycle duct entrance  340  can be greater than the pressure at the recycle duct exit  345 . The pressure differential across the recycle duct  70  results in air flow in the recycle duct  70  that can carry fibrous material to be re-deposited on the core pocket  50  as the core pocket  50  slides over the central recycle zone  275  and the edge zones  260  adjacent the central recycle zone  275 . In addition to the pressure differential in the recycle duct  70  resulting from the different pressures on the zones of the air-distribution manifold  60 , the scarfing roll  80  can impart momentum to the fibers  12  as the fibers  12  are scraped away from the outwardly facing free surface of the fibrous article  100  if the scarfing roll  80  rotates counter to the movement of the core pocket  50 . 
         [0111]    The air pressure on the central recycle zone  275  can be less than, the same, or more than the pressure on the central scarfing zone  295 . The air pressure on the central recycle zone  275  can be less than, the same, or more than the pressure on the edge scarfing zone  315 . 
         [0112]    The process of forming an air-laid fibrous article can be thought of in terms of applying a series of pressures to different portions of the core pocket as the air-laid fibrous article is formed. The pressure applied at the central zone  240  can be thought of as a first pressure. The pressure applied at the edge zones  260  can be thought of as a second pressure. The pressure applied at the central recycle zone  275  can be thought of as a third pressure. The pressure applied at the central scarfing zone  295  can be thought of as a fourth pressure. The pressure applied at the edge scarfing zones  315  can be thought of as a fifth pressure. The pressure applied at the hold down zone  330  can be thought of as a sixth pressure. 
         [0113]    Apparatus  10  can further comprise forming zone shields  370 . Forming zone shields  370  can be configured such that as the core pocket  50  moves through the forming zone  1 , the amount of air flow into the core pocket  50  from the surrounding environment is negligible. In other words, the core pocket  50  can be described as being in slideable and sealable engagement with the forming zone shields  370 . The forming zone shields  370  can be comprised of any material that is impervious to air-flow and is suitable for use in high speed manufacturing operations. The seal between the forming zone shields  370  and the core pocket  50  can be comprised of horse hair fiber and felt. The seal between the forming zone shields  370  and core pocket  50  need not completely separate the core pocket  50  from the surrounding environment. Rather, the core pocket  50  can be separated from the surrounding environment in a manner sufficient to prevent unacceptable contamination of the air-laid fibrous article  100  from occurring during formation and to permit sufficient control of air pressures applied to different portions of the core pocket  50  by the air-distribution manifold  60 . 
         [0114]      FIG. 13  illustrates a cross section, as marked in  FIG. 1 , in which the operative relationship between the forming zone shields  370 , core pocket  50 , air-distribution manifold  60 , recycle duct exit  345 , and recycle duct  70  are shown. As shown in  FIG. 12  the forming zone shields  370  can be positioned to be in slideable and sealable relationship with the core pocket  50 . 
         [0115]    The drylap web  8  can be a web of cellulosic material such as wood pulp or other natural or synthetic fibers. In describing the fibers as being air-entrained, other gaseous mediums are also understood to be suitable. 
         [0116]    The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”. 
         [0117]    All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this written document conflicts with any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this written document shall govern. 
         [0118]    While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.