Patent Publication Number: US-2020289342-A1

Title: Absorbent cores and methods for forming absorbent cores

Description:
FIELD OF THE INVENTION 
     The field of this disclosure relates generally to absorbent cores and methods of manufacturing absorbent cores for use in absorbent articles, and more specifically to pulpless absorbent cores and methods of forming pulpless absorbent cores for use in absorbent articles, such as diapers, training pants, incontinence products, disposable underwear, medical garments, feminine care articles, absorbent swim wear, and the like. 
     BACKGROUND 
     Absorbent cores are used in different types of products to control and contain bodily fluids and other bodily liquid discharge. Many present absorbent cores include pulp fluff, or other cellulosic fibers, which act to absorb the discharged liquids. Present absorbent articles can also contain particulate material, for example superabsorbent material, mixed in with the cellulose fibers to greatly increase the absorbent capacity of the absorbent cores. In these instances, the cellulose fibers help to absorb discharged fluids and also to stabilize the superabsorbent material, for instance maintaining the location of the superabsorbent material within the absorbent cores. However, the presence of cellulose fibers in these absorbent cores imparts a significant amount of bulk to the absorbent cores. Accordingly, absorbent cores that have a high absorbent capacity and do not contain cellulose fibers, or do not contain a substantial amount of cellulose fibers, in order to reduce bulk may be desirable. 
     BRIEF SUMMARY OF THE INVENTION 
     This disclosure relates generally to absorbent cores and methods of manufacturing absorbent cores for use in absorbent articles, and more specifically to pulpless absorbent cores and methods of forming pulpless absorbent cores for use in absorbent articles, such as diapers, training pants, incontinence products, disposable underwear, medical garments, feminine care articles, absorbent swim wear, and the like. 
     In a first embodiment, an absorbent core may comprise a carrier sheet having a first edge region, a central region, and a second edge region, and particulate material disposed on the carrier sheet through the first edge region, the central region, and the second edge region. The absorbent core may have an absorbent core width and the central region has a central region width, and the central width may comprise between 33% and 75% of the absorbent core width. In some embodiments, the central region may comprise an average basis weight that is greater than 110% of an average basis weight of at least one of the first edge region and the right second edge region. 
     Additionally, or alternatively, in further embodiments according to the first embodiment, the central region width may be between 62% and 67% of the absorbent core width. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the first embodiment, the central region may comprise an average basis weight that is greater than 130% of an average basis weight of at least one of the first edge region and the second edge region. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the first embodiment, the particulate material may comprise absorbent particulate material. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the first embodiment, the particulate material may comprise superabsorbent material. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the first embodiment, the absorbent core may further comprise cellulose fibers, wherein the cellulose fibers comprise less than 10% of an overall weight of the absorbent core. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the first embodiment, the absorbent core may further comprise a first adhesive and a second adhesive, and the first adhesive and the second adhesive may be different adhesives. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the first embodiment, the first adhesive may comprise a hot melt adhesive, and the second adhesive may comprise a spray application aqueous binder (SAAB) adhesive. 
     In a second embodiment, an absorbent core may comprise a carrier sheet, the carrier sheet comprising: a front core region with a front core region length, a rear core region with a rear core region length, front ear regions, and rear ear regions, and particulate material disposed on the carrier sheet. The front core region length may comprise half of an overall absorbent core length, and greater than 60% of the particulate material within the absorbent core is may be located within the front core region. In some embodiments, an average basis weight of the absorbent core within the front ear regions may be greater than an average basis weight of the absorbent core within the rear ear regions. 
     Additionally, or alternatively, in further embodiments according to the second embodiment, the front core region may have an average basis weight that is between 110% and 170% of an average basis weight of the rear core region. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the second embodiment, the front core region may have an average basis weight that is between 125% and 150% of an average basis weight of the rear core region. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the second embodiment, greater than 70% of the particulate material within the absorbent core may be located within the front core region. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the second embodiment, the absorbent core may further comprise cellulose fibers, and the cellulose fibers may comprise less than 10% of an overall weight of the absorbent core. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the second embodiment, the absorbent core may further comprise a first adhesive and a second adhesive, and the first adhesive and the second adhesive may be different adhesives. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the second embodiment, the first adhesive may comprise a hot melt adhesive, and the second adhesive may comprise a spray application aqueous binder (SAAB) adhesive. 
     In a third embodiment, an absorbent core may comprise a carrier sheet, a first layer of particulate material disposed on the carrier sheet and having a first layer width, and a second layer of particulate material disposed on the carrier sheet and having a second layer width. The second layer width may be smaller than the first layer width, and the second layer of particulate material may comprise a matrix of particulate material and adhesive. 
     Additionally, or alternatively, in further embodiments according to the third embodiment, the second layer width may comprise between 25% and 75% of the first layer width. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the third embodiment, the second layer may comprise between 33% and 66% of the first layer width. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the third embodiment, the absorbent core may further comprise an adhesive disposed between the first layer of particulate material and the carrier sheet. 
     Additionally, or alternatively, in further embodiments according to any of the above embodiments with respect to the third embodiment, the particulate material may comprise superabsorbent material (SAM). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic of an example forming assembly for forming absorbent cores. 
         FIG. 2  is a perspective view of an exemplary forming drum that may be used in the assembly of  FIG. 1 . 
         FIG. 3  is a side view of an example forming drum and associated components that may be used in the assembly of  FIG. 1 . 
         FIG. 4A  is a side view of an exemplary particulate material delivery chamber that may be used in the assembly of  FIG. 1 . 
         FIG. 4B  is a front view of an exemplary particulate material delivery chamber that may be used in the assembly of  FIG. 1 . 
         FIG. 5  is an illustration of an exemplary absorbent core structure that may be produced by the assembly of  FIG. 1 . 
         FIG. 6A  is a cross-section view of an exemplary absorbent core that may be produced by the assembly of  FIG. 1 . 
         FIG. 6B  is a cross-section view of an alternative exemplary absorbent core that may be produced by the assembly of  FIG. 1 . 
         FIG. 7  is an alternative schematic of an example forming assembly for forming absorbent cores. 
         FIG. 8  is a cross-section view of an alternative exemplary absorbent core that may be produced by the assembly of  FIG. 1  or  FIG. 7 . 
         FIG. 9  is a perspective view of a forming drum including a plurality of masking members for forming shaped absorbent cores. 
         FIG. 10  is a top view of a masking member disposed on the forming drum of  FIG. 9 . 
         FIG. 11  is an illustration of an exemplary shaped absorbent core structure that may be produced using the forming drum and masking members of  FIGS. 9 and 10 . 
         FIG. 12  is a schematic of an example forming assembly for forming absorbent cores including both cellulose fibers and particulate material. 
         FIG. 13  depicts a cross-section of an exemplary absorbent core that may for formed by the forming assembly of  FIG. 12 . 
         FIGS. 14A and 14B  are illustrations of carrier sheets that may be used to form absorbent cores. 
         FIG. 15  is a front view of an alternate exemplary particulate material delivery chamber that may be used in the assembly of  FIG. 1  having a particulate material conduit with an inlet having an inlet width that is smaller than a forming surface width. 
         FIG. 16  is an illustration of an exemplary absorbent core structure that may be produced by using the particulate material delivery chamber if  FIG. 15 . 
         FIG. 17  is an illustration of another exemplary absorbent core structure that may be produced by using the particulate material delivery chamber if  FIG. 15 . 
         FIG. 18  is a plan view of an exemplary masking member defining an absorbent core region, according to aspects of the present disclosure. 
         FIG. 19A  is an internal view of an exemplary particulate absorbent material delivery conduit including particulate absorbent material depositing onto absorbent core regions of a carrier sheet. 
         FIG. 19B  is another internal view of the exemplary particulate absorbent material delivery conduit of  FIG. 19A  where the base carrier sheet has advanced further through the exemplary particulate absorbent material delivery conduit. 
         FIG. 20  is an illustration of exemplary absorbent cores that may be produced according to aspects of the present disclosure. 
         FIG. 21  is a cross-section view of an exemplary absorbent core taken along line D-D′ of  FIG. 20 . 
         FIGS. 22A and 22B  depict top-down internal schematic views of exemplary components that may be used to form a matrix layer of particulate absorbent material and adhesive. 
         FIG. 23  is a side-view of the exemplary components of  FIG. 22A . 
         FIG. 24  is an illustration of a length of formed absorbent cores that may be formed using the components of  FIG. 22A . 
         FIG. 25  depicts a cross-section of an exemplary absorbent core taken along line B-B′ in  FIG. 24  which includes a matrix layer. 
         FIG. 26  depicts a cross-section of another exemplary absorbent core taken along line B-B′ in  FIG. 24  which includes a matrix layer 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, the use of “top”, “bottom”, “above”, “below” and variations of these terms is made for convenience, and does not require any particular orientation of the components. 
     With reference now to the drawings,  FIG. 1  depicts a schematic drawing of an example absorbent core forming apparatus  20 , which may be used to form absorbent cores. A few components of apparatus  20  include the forming drum  26  and the particulate material delivery chambers  60   a,    60   b.  Accordingly, in some embodiments, apparatus  20  may be used to form absorbent cores comprising particulate material. Superabsorbent material (SAM) is one example of particulate material contemplated by this disclosure. In at least some of these embodiments, the particulate material content of the formed absorbent cores may comprise the majority, by weight, of the contents of the absorbent cores. In other embodiments, the particulate material content of the formed absorbent cores may comprise between 90%-100%, by weight, of the contents of the absorbent cores. These absorbent cores may be described herein as pulpless absorbent cores. As used herein, the phrase pulpless absorbent cores may include both absorbent cores that are truly pulpless and absorbent cores that are only substantially pulpless which have cellulose fibers comprising between 0.5%-10%, by weight, of the total contents of the absorbent cores. Pulpless cores may have one or more advantages relative to absorbent cores that have higher cellulose fiber content. For example, pulpless cores can have absorbent properties, such as absorbent capacity, similar to cores with higher cellulose fiber content. However, pulpless cores can have smaller dimensions than cores having cellulose fiber pulp content. In particular, the pulpless cores may have a reduced thickness in comparison to cores with higher cellulose fiber content. 
     In the exemplary embodiment of  FIG. 1 , a base carrier sheet  70  may be unwound from a carrier sheet roll  72 . One or more material handling rollers  74  may be used to transport the base carrier sheet  70  proximate forming drum  26 . Once in proximity to forming drum  26 , the base carrier sheet  70  may be drawn to forming drum  26  by vacuum pressure, described in more detail below in relation to  FIGS. 2 and 3 . The forming drum  26  rotates in the direction of arrow  10 , about drive-shaft  28 , advancing the base carrier sheet  70  through one or more absorbent core forming stages, ultimately resulting in the absorbent cores  101 . Although absorbent cores  101  are shown as discrete pads, in other embodiments, absorbent cores  101  may be formed as a continuous ribbon. 
     In some embodiments, the base carrier sheet  70  may comprise a nonwoven material such as a meltblown, spunbond-meltblown-spunbond (SMS), spunlace material, or a natural tissue material. However, in other embodiments, any suitable non-woven material may be used. The base carrier sheet  70  should be at least semi-permeable to air-flow. For instance, the base carrier sheet  70  should be sufficiently permeable such that air is be able to move through the base carrier sheet  70  from a top surface disposed away from the forming surface  24  to a bottom surface disposed proximate the forming surface  24 , and ultimately through forming surface  24  into the interior of forming drum  26 . Some example suitable dimensions of the base carrier sheet  70  include a width between about 7 cm to about 36 cm. Some example suitable basis weights for the base carrier sheet  70  range from about 5 grams per square meter (gsm) to about 50 gsm. However, the specific dimensions and basis weights used for the base carrier sheet  70  may differ, even outside of these ranges, based on the specific application or desired properties for the absorbent cores  101 . 
     In the example of  FIG. 1 , the base carrier sheet  70  first moves through first adhesive application zone  80 , where adhesive applicator  76  applies adhesive  78  to the base carrier sheet  70 . In some examples, the adhesive  78  may be a hot-melt adhesive, such as either a contact hot-melt adhesive or a non-contact hot-melt adhesive. Although, in other examples, adhesive  78  may be any other suitable adhesive for application on a carrier sheet. Further, adhesive  78  may be applied using any suitable application technique or techniques. For instance, adhesive  78  may be applied with a spray application, with a slot-coat application, or by any other appropriate application technique. 
     After exiting first adhesive application zone  80 , the base carrier sheet  70 , now containing adhesive  78 , is brought in proximity to forming drum  26 , where the base carrier sheet  70  is drawn to the forming drum through vacuum pressure. The base carrier sheet then enters particulate material delivery chamber  60   a.  Inside of particulate material delivery chamber  60   a,  particulate material may be deposited onto the base carrier sheet  70 . More specifically, the particulate material may be deposited onto adhesive  78 , where the particulate material becomes stabilized, or immobilized on the base carrier sheet  70 , by adhesive  78 . 
     The hopper  90  in  FIG. 1  may contain particulate material that is delivered to the particulate material delivery chambers  60   a,    60   b.  The connecting pipe  68  may connect directly to the hopper  90  in order to transport the particulate material from the hopper  90  to the particulate material delivery chambers  60   a,    60   b.  In at least some embodiments, the connecting pipe  68  may include metering device  92 . The metering device  92  may be any sort of bulk material metering device, based on volumetric, gravimetric, or mass flow principles, or the like. The metering device  92  may ensure that only a specified amount (for instance, by volume or by weight) of particulate material flows through the connecting pipe per unit of time. Some example suitable ranges for the volume of particulate material flowing through the metering device  92  are between about 5,000 grams per minute (g/min) and about 25,000 g/min. In this manner, the metering device  92  can help to ensure a proper amount of particulate material is delivered to particulate material delivery chambers  60   a,    60   b.    
     In the example shown in  FIG. 1 , the connecting pipe  68  may split into delivery pipes  64  and  66 . Each of the delivery pipes  64  and  66  may enter the particulate material delivery chambers  60   a,    60   b,  forming particulate material delivery conduits  62   a,    62   b.  The particulate material delivered to the particulate material delivery chambers  60   a,    60   b  may exit the particulate material delivery conduits  62   a,    62   b  and be deposited onto the adhesive  78  and the base carrier sheet  70 . In some alternative embodiments, instead of a single metering device  92 , multiple metering devices may be used to ensure proper delivery of particulate material to each of the particulate material delivery chambers  60   a,    60   b.  For example, each of the delivery pipes  64  and  66  may include a metering device, represented by the dashed boxes  93   a  and  93   b  in  FIG. 1 , instead the apparatus  20  including metering device  92 . 
     After exiting the particulate material delivery chamber  60   a,  the base carrier sheet  70 , now containing adhesive  78  and particulate material, may enter second adhesive application zone  81 . In some embodiments, second adhesive application zone  81  may be similar to first adhesive application zone  80 . For example, in second adhesive application zone  81 , adhesive applicator  86  may apply adhesive  88  to the base carrier sheet  70 . More specifically, adhesive applicator  86  may apply adhesive  88  onto the particulate material that is stabilized on the base carrier sheet  70 . In some embodiments, adhesive  88  may be the same as adhesive  78 . For instance, adhesive  88  may also be a hot-melt adhesive, such as a non-contact hot-melt adhesive. Adhesive  88  may also be applied to the base carrier sheet  70  in a similar manner as adhesive  78  was applied to the base carrier sheet  70 , such as with a spray application. Although, in other embodiments, adhesive  88  may be a different type of adhesive than adhesive  78  and/or may be applied in a different manner than adhesive  78 . 
     In still other embodiments, adhesive  88  may not be a hot-melt adhesive. In some embodiments, adhesive  88  may be a spray-application aqueous binder (SAAB) adhesive. Where adhesive  88  is a SAAB adhesive, adhesive  88  may be applied with a spray-application. Implementing adhesive  88  as a SAAB adhesive may be preferable in certain embodiments, as SAAB adhesives may be able to better penetrate particulate material than hot-melt adhesives, thereby allowing for greater stabilization of the particulate material deposited onto the base carrier sheet  70 . 
     After passing through second adhesive application zone  81 , the base carrier sheet  70  now includes a first adhesive, adhesive  78 , disposed on the base carrier sheet  70 , a first amount of particulate material  89  (as can be seen in further detail in  FIG. 6A ) disposed on the adhesive  78 , and a second adhesive, adhesive  88 , disposed on the first amount of particulate material. The base carrier sheet  70  then enters the particulate material delivery chamber  60   b.  In the particulate material delivery chamber  60   b,  a second amount of particulate material is deposited onto adhesive  88  in a similar manner as particulate material was deposited onto adhesive  78  in the particulate delivery chamber  60   a.    
     In some embodiments, the particulate material delivered to the base carrier sheet  70  in the particulate material delivery chambers  60   a,    60   b  may be the same type of particulate material. In other embodiments, however, the type of particulate material delivered to the base carrier sheet  70  in the particulate material delivery chamber  60   a  may be different than the type of particulate material delivered to the base carrier sheet  70  in the particulate material delivery chamber  60   b.  In such embodiments, apparatus  20  may have two separate hoppers that each store different types of particulate material, in contrast to the example of  FIG. 1 . Additionally, separate connecting and delivery pipes may connect to each of the hoppers and to each of the particulate material delivery chambers  60   a,    60   b  to maintain separation of the different particulate material types. Alternatively, apparatus  20  may still include only the single hopper  90  and the connecting and delivery pipes  68 ,  64 , and  66 , as shown in  FIG. 1 . In such embodiments, the hopper  90  may have two separate internal compartments to maintain separation of the different particulate material types. Additionally, connecting pipe  68  may include separate internal lumens. A first of the internal lumens may connect to a first internal compartment of the hopper  90  and to delivery pipe  64 , while a second of the internal lumens may connect to a second internal compartment of the hopper  90  and to delivery pipe  66 . 
     As mentioned previously, in some embodiments the particulate material may comprise superabsorbent material (SAM). Suitable superabsorbent materials are well known in the art and are readily available from various suppliers. Example suitable superabsorbent materials may include BASF  9700 , available from BASF Corporation, a business having offices located in Charlotte, N.C., U.S.A; and Evonik 5600, available from Evonik Industries, a business having offices located in Parsippany, N.J., U.S.A. 
     In other embodiments, the particulate material may comprise low- or non-absorbent material such as charcoal, sugar (e.g. xylitol or the like), or encapsulated material. Accordingly, this disclosure contemplates in any of the disclosed embodiments that the delivered particulate material may be either an absorbent material, a non-absorbent material, or both. For instance, absorbent particulate material may be mixed with non-absorbent particulate material, or a first of the particulate material delivery chambers  60   a,    60   b  may deliver absorbent particulate material and a second of the particulate material delivery chambers  60   a,    60   b  may deliver non-absorbent particulate material. 
     Once the second amount of particulate material has been deposited onto the base carrier sheet  70 , a top carrier sheet  75  may be applied onto the second amount of particulate material. The top carrier sheet  75  may be unwound from a roll  77  of top carrier sheet material, and may be transported proximate the forming drum  26  via one or more material handling rollers  79 . After the top carrier sheet  75  has been applied onto the second amount of particulate material, the edges of the top carrier sheet  75  and the base carrier sheet  70  may be bonded together (not shown) to form the pulpless absorbent cores  101 . The absorbent cores  101  may then be transported on conveyer  95  for further processing. 
     In some embodiments, material handling roller  79  may also perform a function similar to a nip roller. For instance, material handling roller  79  may come into close proximity to conveyer  95  in region  99  and the absorbent core  101  may be compressed to reduce bulk and/or to more securely bond the portions of the absorbent core  101  together. In other embodiments, however, one or more separate rollers may perform a nip function, such as rollers  85 . 
     In some alternative embodiments, a third adhesive may be applied to the second amount of particulate material before the top carrier sheet  75  is applied to the second amount of particulate material. In some of these embodiments, apparatus  20  may further include third adhesive application zone  91   a.  Where apparatus  20  includes third adhesive application zone  91   a,  adhesive applicator  96   a  may apply adhesive  98   a  to the second amount of particulate material before the top carrier sheet  75  is applied. In various embodiments, adhesive  98   a  may be similar to either adhesive  78  or adhesive  88  described previously, and may be applied in any of the previously described methods. In different embodiments, however, apparatus  20  may include third adhesive application zone  91   b  instead of third adhesive application zone  91   a.  In these embodiments, adhesive applicator  96   b  may apply adhesive  98   b  directly to the top carrier sheet  75 , instead of onto the second amount of particulate material. Additionally, adhesive  98   b  may be similar to either adhesive  78  or adhesive  88  described previously, except that adhesive  98   b  may not be a SAAB adhesive, as SAAB adhesives may not be suitable for direct application to carrier sheets. Further, adhesive  98   a  may be applied in any of the previously described methods. This third adhesive, applied by either adhesive applicator  96   a  or adhesive applicator  96   b,  may further help to stabilize the second amount of particulate material and/or to more securely attach the top carrier sheet  75  to the second amount of particulate material. 
     The adhesive applicators  76 ,  86 , and/or  96   a  or  96   b  may be configured to apply adhesive in a continuous manner in some embodiments. In other embodiments, however, the adhesive applicators  76 ,  86 , and/or  96   a  or  96   b  may be configured to apply adhesive in an intermittent fashion. For instance, the adhesive applicators  76 ,  86 , and/or  96   a  or  96   b  may be applied intermittently to target zones on the base carrier sheet  70  to help stabilize the particulate material at locations on the base carrier sheet that will be most effective in absorbing liquid in the resulting absorbent cores due to the placement of the absorbent cores within an absorbent article. 
     Additionally, in at least some embodiments, the adhesive applicators  76 ,  86 , and/or  96   a  or  96   b  may apply adhesive in a coordinated, intermittent fashion. In these embodiments, the adhesive applicator  86  may apply adhesive intermittently in a fashion such that the adhesive applicator  86  applies adhesive on top of the adhesive applied by adhesive applicator  76 . After application of adhesive by the adhesive applicator  86 , the adhesive applied by the adhesive applicator  86  would overlay the adhesive applied by the adhesive applicator  76 . In embodiments that include adhesive applicator  96   a  or  96   b,  the adhesive applicator  96   a  or  96   b  may apply adhesive in an intermittent fashion such that the adhesive applied by the adhesive applicator  96   a  or  96   b  overlays the adhesive applied by the adhesive applicator  76  and the adhesive applied by the adhesive applicator  86 . 
       FIGS. 2 and 3  more closely depict portions of apparatus  20 , including forming drum  26 . The forming drum  26  includes a movable, foraminous forming surface  24 , indicated by the hatched pattern in  FIG. 2 , extending around the circumference of the forming drum  26 . The forming drum  26  is mounted on a drive shaft  28  and supported by bearings  30  (as can be seen in  FIG. 3 ). The forming drum  26  includes a circular drum wall (not shown) operatively connected to and rotated by the drum drive shaft  28 . The shaft  28  is driven in rotation by a suitable motor or line shaft (not shown) in a clockwise direction as depicted by the arrows in  FIG. 3 . In some embodiments, the drum wall can be a primary, load-bearing member, and the drum wall can extend generally radially and circumferentially about the drum drive shaft  28 . 
     A vacuum duct  36  located radially inwardly of the forming surface  24  extends over an arc of the interior of the forming drum  26 . The vacuum duct  36  is in fluid communication with the forming surface  24  for drawing air through the forming surface  24 . The vacuum duct  36  is mounted on and in fluid communication with a vacuum supply conduit  40  connected to a vacuum source  42 . The vacuum source  42  may be, for example, an exhaust fan and may create a vacuum within the forming drum which may be between about 2 inches of H 2 0 to about 40 inches of H 2 0. Beyond helping the base carrier sheet  70  adhere to the forming drum  26  as the base carrier sheet  70  advances around the forming drum, the vacuum pressure created by the vacuum source  42  may help to pull the particulate material exiting the particulate material delivery conduits  62   a,    62   b  toward the forming surface  24 . This vacuum pressure may help to spread the particulate material out on the forming surface  24  and to help form a more even distribution of the particulate material along the cross-machine direction  56  of the base carrier sheet  70 . 
     The vacuum duct  36  is connected to the vacuum supply conduit  40  along an outer peripheral surface of the vacuum supply conduit  40 , and extends circumferentially about at least a portion of the vacuum supply conduit  40 . The vacuum duct  36  projects radially outwardly from the vacuum supply conduit  40  toward the forming surface  24  and includes axially spaced side walls  34  and angularly spaced end walls  46 . 
     The shaft  28  extends through the drum wall and into the vacuum supply conduit  40  where it is received in the bearing  30 . The bearing  30  is sealed with the vacuum supply conduit  40  so that air is not drawn in around the shaft  28  where it enters the vacuum supply conduit  40 . 
     As representatively shown, the vacuum supply conduit  40  can include a conduit end wall  48  and a peripheral wall  50  that delimit the size and shape of the vacuum supply conduit  40 . The vacuum supply conduit  40  can have any suitable cross-sectional shape. In the illustrated configuration, the vacuum supply conduit  40  has a generally circular cross-sectional shape. The vacuum supply conduit  40  can be operatively held in position with any suitable support structure. The support structure can also be joined and connected to further components or members that operatively support the portions of the vacuum supply conduit  40  structure that engage the drum drive shaft  28 . For example, in the exemplary embodiment, one or more supports may connect to the bearing  30 , and the entire vacuum supply conduit  40  may be supported by an overhead mount (not shown). 
     In the illustrated embodiment, walls  34  extend generally radially and circumferentially about the vacuum supply conduit  40 . A drum rim  52  is joined to the walls  34  and is constructed and arranged to provide a substantially free movement of air through the thickness of the drum rim  52 . The drum rim  52  is generally cylindrical in shape and extends along the direction of the drum axis  53 , and circumferentially about the drum axis  53 . As representatively shown, the drum rim  52  can be supported by and extend between the walls  34 . 
     With reference to  FIGS. 2 and 3 , the forming surface  24  can be provided along the outer, cylindrical surface of the forming drum  26 , and can extend along the axial and circumferential dimensions of the forming drum. The circumferential dimension is generally in a machine direction  54  and the axial dimension is generally in a cross-machine direction  56 . The structure of the forming surface  24  can be composed of an assembly, and can include a foraminous member  58 , which is operatively connected and joined to the forming drum  26 . In some contemplated embodiments, the foraminous member  58  may be comprised of a system of multiple inserts. Exemplary foraminous members that may be used in conjunction with the present disclosure are further described in U.S. Pat No. 6,630,088, titled “Forming media with enhanced air flow properties”, filed on Oct. 23, 2000. 
     The forming surface  24  can be operatively held and mounted on the drum rim  52  by employing any suitable attachment mechanism. As one representative example, a system of nuts and bolts can be employed to secure the forming surface  24  onto an operative set of mounting rings. In such an example, the mounting rings can be operatively mounted on and secured to the drum rim  52 . In other embodiments, the foraminous member  58  may be integral with forming drum  26 . 
     Although not shown in  FIG. 2 , one or more masking plates may be attached to forming drum  26  on top of forming surface  24 , as described in more detail below. The masking plates, for example, may be attached to drum rim  52 , or alternately to the foraminous forming member  58 . The masking plates may cover a portion of the forming surface  24  in order to block the vacuum in particular portions of the forming surface. The masking plates may allow for differently shaped absorbent cores to be formed on the forming drum  26 , as will be explained in more detail below. 
     Suitable forming drum systems for use with the present disclosure are well known in the art. For example, see U.S. Pat. No. 4,666,647 entitled APPARATUS AND METHOD FOR FORMING A LAID FIBROUS WEB by K. Enloe et al. which issued May 19, 1987; and U.S. Pat. No. 4,761,258 entitled CONTROLLED FORMATION OF LIGHT AND HEAVY FLUFF ZONES by K. Enloe which issued Aug. 2, 1988; the entire disclosures of which are incorporated herein by reference in a manner that is consistent herewith. Other forming drum systems are described in U.S. Pat. No. 6,330,735, entitled APPARATUS AND PROCESS FOR FORMING A LAID FIBROUS WEB WITH ENHANCED BASIS WEIGHT CAPABILITY by J. T. Hahn et al. which issued Dec. 18, 2001, the entire disclosure of which is incorporated herein by reference in a manner that is consistent herewith. Systems for forming surfaces are described in U.S. Pat. No. 6,3630,088, entitled FORMING MEDIA WITH ENHANCED AIR FLOW PROPERTIES by Michael Barth Venturino et al. which issued Oct. 7, 2003, the entire disclosure of which is incorporated herein by reference in a manner that is consistent herewith. 
     With respect to  FIG. 3 , additional features of the particulate material delivery chambers  60   a,    60   b  are evident. For instance, the particulate material delivery chambers  60   a,    60   b  further depict the particulate material delivery conduits  62   a,    62   b  terminating in inlets  61   a,    61   b.  The inlets  61   a,    61   b,  e.g. the plane of the opening of the particulate material delivery conduits  62   a,    62   b,  may be positioned within the particulate material delivery chambers  60   a,    60   b  such that the inlets  61   a,    61   b  are generally parallel with ground  94  and/or with the base of the forming drum  87 . In these embodiments, the particulate material delivered from the inlets  61   a,    61   b  may exit the inlets  61   a,    61   b  in a stream that is substantially perpendicular to the ground  94  and/or the base of the forming drum  87 . Additionally, the particulate material delivery chambers  60   a,    60   b  are both situated on the top half of the forming drum  26 . In this configuration, the particulate material delivered from the particulate material delivery chambers  60   a,    60   b  may fall with gravity towards the forming drum, instead of requiring additional energy to push the particulate material to the forming drum  26  against gravity. 
     However, in other embodiments, the inlets  61   a,    61   b  may be tilted with respect to the ground  94  and/or the base of the forming drum  87 . For instance, the inlets  61   a,    61   b  may form an angle  97  with respect to the ground  94  and/or the base of the forming drum  87  (shown only with respect to inlet  61   a  in  FIG. 3 ) having a value of between about 1 degree and about 45 degrees. In even further embodiments, the inlets  61   a,    61   b  may form an angle  97  with respect to the ground  94  and/or the base of the forming drum  87  such that the inlets  61   a,    61   b  are tangential to the forming drum  26 . 
       FIGS. 4A and 4B  depict different close-up views of particulate material delivery chamber  60   a.    FIG. 4A  depicts a close-up of particulate material delivery chamber  60   a  as viewed in the machine direction  54 .  FIG. 4A  further depicts individual particulate material particles  89  exiting inlet  61   a  of particulate material delivery conduit  62   a  and being deposited onto the base carrier sheet  70 . The individual particulate material particles  89  can also be seen disposed and stabilized on the portion of the base carrier sheet  70  after the particulate material delivery chamber  60   a  in the machine direction  54 . 
     As mentioned previously, the particulate material may be delivered through particulate material delivery conduit  62   a  from the hopper  90 , which results in the particulate material being gravity fed to inlet  61   a.  In some embodiments, the individual particulate material particles  89  exiting inlet  61   a  may exit with a velocity that is less than 1200 meters per minute (m/min). In other embodiments, the individual particulate material particles  89  exiting inlet  61   a  may exit with a velocity that is less than 900 m/min. In still other embodiments, the individual particulate material particles  89  exiting inlet  61   a  may exit with a velocity that is less than 600 m/min. In yet other embodiments, the individual particulate material particles  89  exiting inlet  61   a  may exit with a velocity that is less than 300 m/min. These velocities are in contrast to particulate material that is introduced to a forming chamber pneumatically. Where particulate material is introduced pneumatically, the minimum possible introduction velocity is over 1200 m/min, because that is the velocity at which air needs to move in order to move particulate material particles. Accordingly, gravity feeding the particulate material into the particulate material delivery chamber  60   a  allows the individual particulate material particles  89  to be introduced proximate the forming drum  26  with a relatively lower velocity than if the particulate material were to be pneumatically introduced. This lower introduction velocity may allow the individual particulate material particles  89  to be influenced to a greater extent by the vacuum pressure of the forming drum  26 . In this manner, the apparatus  20  may be able to achieve a more even distribution of the individual particulate material particles  89  on the base carrier sheet  70  throughout the cross-machine direction  56  than if the individual particulate material particles  89  we introduced into the particulate material delivery chamber  60   a  pneumatically. 
       FIG. 4B  depicts an internal view of particulate material delivery chamber  60   a  as viewed from the cross-machine direction  56 . As can be seen in  FIG. 4B , the forming drum  26  may have a drum width  110 , and the forming surface  24  may have a forming surface width  111 . Generally, the drum width  110  will be greater than the forming surface width  111 , as the forming drum  26  will include drum rim  52 . However, this is not necessary in all embodiments.  FIG. 4B  also depicts the forming surface  24  as a relatively uniform and continuous surface. As mentioned previously, an as will be described in more detail below, in different embodiments one or more masking plates may obscure portions of the forming surface  24 . 
     Also shown in  FIG. 4B  is the particulate material delivery conduit  62   a  and inlet  61   a  having an inlet width  112 . In some embodiments, the inlet width  112  may be the same as the forming surface width  111 . However, in other embodiments, the inlet width  112  may be smaller or greater than the forming surface width  111 . For instance, the inlet width  112  may be the same as the drum width  110 . In other examples, the inlet width  112  may smaller than the forming surface width  111 , such as be between about one-quarter and about nine-tenths of the forming surface width  111 . Additionally, inlet width  112  may be different for each of particulate material delivery conduits  62   a,    62   b.    
     The particulate material delivery conduit  62   a  may further having a vertical conduit spacing  114  comprising an amount of space between the inlet  61   a  of the particulate material delivery conduit  62   a  and the forming surface  24 . In some examples, the vertical conduit spacing  114  may be between about 15 cm to about 100 cm. 
     As shown in  FIG. 4B , the particulate material delivery chamber  60   a  may not be sealed against the forming drum  24 . For instance, there may be a gap between the bottom edges  113  of the particulate material delivery chamber  60   a  and the forming surface  24  or the forming drum  26 . The gap may have a gap space  116  that can be between about 0.5 cm and about 5 cm. In these embodiments, air may be able to enter into the particulate material delivery chamber  60   a  through gap space  116 , as shown by arrows  117 . Entry of air into the particulate material delivery chamber  60   a  may push the particulate material  89  toward a center of the forming surface  24  as the particulate material falls from the inlet  61   a  to the forming surface  24 . This may result in a cross-direction  56  width of the particulate material  89  deposited at the forming surface  24  that is less than inlet width  112 . This may result in more particulate material  89  present in a central region of formed absorbent cores than if there were no gap space  116 . In some alternative embodiments, gap space  116  may not be disposed between the bottom edges  113  of the particulate material delivery chamber  60   a  and the forming surface  26 . Rather, the bottom edges  113  of the particulate material delivery chamber  60   a  may be sealed against the forming drum  26 , and a separate hole may be disposed through a side wall of the particulate material delivery chamber  60   a  to allow entry of air into the particulate material delivery chamber  60   a.    
     Accordingly, in other embodiments, there may not be a gap space  116  between the bottom edges  113  of the particulate material delivery chamber  60   a  and the forming surface  24  or the forming drum  26 . For instance, the bottom edges  113  of the particulate material delivery chamber  60   a  may contact the forming surface  24  or the forming drum  26 , or one or more gap fillers (not shown) may be positioned to close up the gap space  116 . In these embodiments, there may be no air entering gap space  116 . Accordingly, there may be no air impinging on the stream of particulate material  89  and pushing the particulate material  89  inward from the edges of the forming surface  24 . In these embodiments, the cross-direction  56  width of the particulate material  89  deposited at the forming surface  24  may be close or equal to the inlet width  112 . 
     In some additional or alternative embodiments, an upper region of the particulate material delivery chamber  60   a  may be open and may allow air to flow into the particulate material delivery chamber  60   a  as shown by arrows  119 . In these embodiments, the inflow of air may cause the particulate material  89  to fall toward the forming surface  24  in a more linear path. For instance, as air enters the particulate material delivery chamber  60   a,  the air may be pulled toward the forming surface  24  by the vacuum pressure in the chamber  60   a,  and may travel in a generally linear manner. The air may pull the particulate material  89  toward the forming surface  24 , and the location of the particulate material  89  deposited at the forming surface  24  may be more heavily influenced by individual starting positions of the particulate material  89  at the inlet  61   a.    
     However, in still other additional or alternative embodiments, an upper region of the particulate material delivery chamber  60   a  may be sealed and may prevent air from entering the particulate material delivery chamber  60   a.  In these embodiments, the air within the particulate material delivery chamber  60   a  may be more turbulent than in the embodiments where the upper region of the particulate material delivery chamber  60   a  allows entry of air, as represented by arrows  121 . In these embodiments, the relatively greater turbulence may cause the particulate material  89  to fall in much less linear paths and, therefore, the location of the particulate material  89  deposited at the forming surface  24  may be less dependent on their initial starting position at the inlet  61   a  than where the upper region of the particulate material delivery chamber  60   a  is open to the air. In at least some of these embodiments, the resulting formed absorbent cores may have a relatively more even distribution of particulate material  89  throughout both the cross-machine direction  56  and the machine direction  54 . 
     Although  FIGS. 4A-B  only depict particulate material delivery chamber  60   a,  it should be understood that particulate material delivery chamber  60   b  may be similar to the depicted particulate material delivery chamber  60   a.  However, it should also be understood that contemplated embodiments of the present disclosure include apparatuses including particulate material delivery chambers  60   a,    60   b  that differ from each other. For instance, particulate material delivery chamber  60   a  may include a first set of features that were described above with respect to  FIGS. 4A-B , while particulate material delivery chamber  60   b  includes a second, different set of features. As one illustrative example, particulate material delivery chamber  60   a  may include an inlet, e.g. inlet  61   a,  that is oriented generally parallel with respect to ground  94  and/or the base of the forming drum  87  while particulate material delivery chamber  60   b  may include an inlet, e.g. inlet  61   b,  that is oriented at an angle of 45 degrees with respect to ground  94  and/or the base of the forming drum  87 . Of course, this is just one example. More generally, each of the particulate material delivery chambers  60   a,    60   b  may include any of the features described above with respect to  FIGS. 4A-B , and the specific set of features of each of particulate material delivery chambers  60   a,    60   b  may not be the same. 
       FIG. 5  depicts pulpless absorbent cores  101  as they may appear when exiting apparatus  20 . In some examples, the absorbent cores  101  may be formed on a continuous carrier sheet, for instance the base carrier sheet  70  as shown in  FIG. 1 . As the base carrier sheet  70  including the various adhesives and particulate material exit off of the forming drum  26 , another continuous carrier sheet, for instance the top carrier sheet  75 , may be applied over the top of the base carrier sheet  70 . In this manner, a continuous length of absorbent core may be formed by apparatus  20 . However, as mentioned previously, in some embodiments, the forming surface  24  may include one or more masking members which may block a portion of the forming surface  24 . In such embodiments, portions of the resulting length of the absorbent core may include gaps where there is no, or relatively little, particulate material content. These gaps are represented by gap regions  115  in  FIG. 5 . As the absorbent cores  101  were being formed on the forming surface  24 , the applied vacuum would have been blocked by the masked portions of the forming surface such that little to no particulate material would have been drawn to the base carrier sheet  70  in gap regions  115 . Accordingly, in such embodiments, discrete absorbent cores  101  may be formed on the continuous base carrier sheet  70 , as shown in  FIG. 5 . The base carrier sheet  70  and the top carrier sheet  75  may later be cut, for instance along cut lines  118 , in order to form separated absorbent cores. In at least some embodiments, a knife roll may be used to cut the base carrier sheet  70  and the top carrier sheet  75  into separated absorbent cores. 
       FIG. 6A  depicts an example cross-section of an absorbent core  101  taken along line A-A′ in  FIG. 5 . In the example of  FIG. 6A , the absorbent core  101  was formed using only two adhesives. For instance, the absorbent core  101  of  FIG. 6A  includes the base carrier sheet  70 . On top of the base carrier sheet  70  is the first adhesive  120 , represented by the ‘x’s. The first adhesive  120 , in some embodiments, may comprise and adhesive such as adhesive  78  described with respect to  FIG. 1 . Adhesive  120  may have been applied to the base carrier sheet  70 , for instance, in the first adhesive application zone  80  of  FIG. 1 . 
     On top of the first adhesive  120  is the first amount of particulate material  122 , represented by particulate material particles  89 . The first amount of particulate material  122  may have been applied to the first adhesive  120 , for example, in the particulate material delivery chamber  60   a  of  FIG. 1 . The first amount of particulate material  122  may have a thickness of between about 0.1 mm and about 1 mm. 
     On top of the first amount of particulate material  122  is the second adhesive  124 , represented by the ‘w’s. The second adhesive  124 , in some embodiments, may comprise an adhesive such as adhesive  88  described with respect to  FIG. 1 . The second adhesive  122  may have been applied to the first amount of particulate material  122 , for instance, in the second adhesive application zone  81  of  FIG. 1 . 
     On top of the second adhesive  124  is the second amount of particulate material  126 . The second amount of particulate material  126  may have been formed, for example, in the particulate material delivery chamber  60   b  of  FIG. 1 . The second amount of particulate material  126  may have a thickness of between about 0.1 mm and about 1 mm. Finally, the top carrier sheet  75  is shown disposed on top of the second amount of particulate material  126 . 
     In some embodiments, some of the adhesive  124  may penetrate into the first amount of particulate material  122 . For instance, in the example of  FIG. 6A , strands of the first adhesive  124  (as represented by the ‘w’s) are shown penetrating the first amount particulate material  122  a distance  130 . In some examples, distance  130  may range from between about 0.1 mm to about 1 mm. Generally, where the adhesive  124  is a SAAB adhesive, the distance  130  may be on the higher end of the range, as SAAB may be more effective at penetrating the first amount of particulate material  122  than other types of adhesives, such as hot-melt adhesive. The greater penetration distance of SAAB may allow for relatively greater stabilization of the particulate material  89  than other types of adhesive that have lesser penetrating ability. 
       FIG. 6B  depicts an example cross-section of an alternative absorbent core  101 ′ taken along line A-A′ in  FIG. 5 . In the example of  FIG. 6B , the absorbent core  101 ′ was formed using three separate adhesive applications. For instance, the absorbent core  101 ′ of  FIG. 6B  may be the same as the absorbent core  101  of  FIG. 6A  except that the absorbent core  101 ′ of  FIG. 6B  further includes third adhesive  128 , which is also represented by ‘w’s. This is because in the embodiment of  FIG. 6B , the second adhesive  124  and the third adhesive  128  are the same adhesive, such as a SAAB adhesive, but may have been applied in separate process steps. 
     The third adhesive  128 , in some embodiments, may comprise adhesive  98   a  of  FIG. 1 . In these examples, the third adhesive  128  may have been applied to the second amount of particulate material  126  in the third adhesive application zone  91   a.  As with the second adhesive  120 , the third adhesive  128  may penetrate at least partially into the particulate material  89 . The penetration distance of the third adhesive  120  is shown by penetration distance  136 , which may range from about 0.1 mm to about 2 mm. In at least some embodiments, the third adhesive  128  may penetrate throughout the entire laminate structure of absorbent core  101 ′. 
     In other embodiments, however, the third adhesive  128  may not be the same as the second adhesive  124 . For instance, in at least some contemplated embodiments, the third adhesive may be applied to the top carrier sheet  75  rather than the second amount of particulate material  126 . In these embodiments, the third adhesive may be a hot-melt adhesive rather than a SAAB adhesive, as SAAB adhesives may not be suitable for application to carrier sheets. Accordingly, the third adhesive  128  may be applied to the top carrier sheet such as in third adhesive application zone  91   b  of  FIG. 1  instead of in third adhesive zone  91   a.    
     In general, as shown in  FIGS. 6A and 6B , absorbent cores  101  and  101 ′ may have overall thicknesses  123 ,  125 , respectively. Some suitable values for thicknesses  123 ,  125  range from between about 0.2 mm to about 2.0 mm. However, as will be described in more detail with respect to  FIG. 8 , the processes described herein may further include additional applications of adhesive and of particulate material, forming even larger laminate structures. 
     In even further additional or alternative embodiments, one or more tissue or other non-woven sheets may be interspersed between the adhesives and particulate material of the absorbent cores  101 ,  101 ′. With specific respect to  FIG. 6A , for instance, in some embodiments an intermediate tissue or other non-woven material (not shown) may be placed on top of the first amount of particulate material  122 . Then, the second amount of particulate material  126  may be deposited onto that intermediate tissue or other non-woven material. In further embodiments, an adhesive may then be applied to the laminate structure, as shown in  FIG. 6B . Although only shown with two separate application of particulate material, as will be described in more detail with respect to  FIG. 8 , contemplated absorbent cores may include any suitable number of applications of particulate material. Accordingly, in such embodiments, an intermediate tissue or other non-woven sheet may be disposed between each adjacent application of particulate material. 
       FIG. 7  depicts an alternative pulpless absorbent core forming apparatus  200 . Pulpless absorbent core forming apparatus  200  may generally be similar to apparatus  20 , except that instead of using a forming drum, pulpless absorbent core forming apparatus  200  uses a planer forming conveyer  226 . Although the apparatus  200  may be slightly different from the apparatus  20 , the method of forming pulpless absorbent cores with the apparatus  200  is very similar to the process described with respect to apparatus  20 . For instance, the base carrier sheet  270  is first fed onto the forming conveyer  226 . The base carrier sheet  270  then encounters adhesive application zone  281 , where adhesive applicator  276  applies adhesive  278  to the base carrier sheet  270 . 
     Next, the base carrier sheet  270  may enter particulate material delivery chamber  260   a.  Particulate material may be delivered to the particulate material delivery chamber  260   a  from the hopper  290  through connecting pipe  268  and delivery pipe  264 . Delivery pipe  264  may enter the particulate material delivery chamber  260   a  and form particulate material delivery conduit  262   a.  The particulate material delivered to the particulate material delivery conduit  262   a  ultimately exits the particulate material delivery conduit  262   a  through inlet  261   a.  In some embodiments, a metering device  292  may be present to meter out a specific amount of particulate material from the hopper  290  to ensure a predetermined amount of particulate material flows to particulate material delivery conduit  262   a.    
     Additionally, in at least some of these embodiments, a vacuum chamber  228   a  may be present under the forming conveyer. For instance, the forming conveyer may have a foraminous forming surface (not shown) and air may be able to move across the foraminous forming surface. In the region of vacuum chamber  228   a,  air may be moving from within the particulate material delivery chamber  260   a  through the foraminous forming surface and into a duct (not shown) coming out of the forming conveyer  226 . This movement of air may pull particulate material exiting inlet  261   a  toward the forming conveyer to be deposited onto the adhesive  278  and the base carrier sheet  270  forming a layer comprising a first particulate material. Although vacuum ducts  228   a  and  228   b  are shown only in the vicinity of the particulate material delivery chambers  260   a,    260   b,  in other embodiments, vacuum chambers  228   a,    228   b  may extend outside of the region around the particulate material delivery chambers  260   a,    260   b  and over a greater extent of the forming conveyer  226  than is shown in  FIG. 7 . 
     After exiting the particulate material delivery chamber  260   a,  the base carrier sheet  270 , now including adhesive  278  and a first amount of particulate material, encounters adhesive application zone  281 . Within adhesive application zone  281 , an adhesive applicator  286  applies adhesive  288  onto the first amount of particulate material that was deposited onto adhesive  278  and the base carrier sheet  270  within the particulate material delivery chamber  260   a.    
     The base carrier sheet  270  may then enter the particulate material delivery chamber  260   b.  Particulate material may be delivered to the particulate material delivery chamber  260   b  through connecting pipe  268  and through delivery pipe  266 . Delivery pipe  266  may enter the particulate material delivery chamber  260   b  and form particulate material delivery conduit  262   b,  which in turn may end at inlet  261   b.  Particulate material delivered from the hopper  290  may exit inlet  261   b  and be drawn toward the adhesive  288  due to vacuum chamber  228   b.  Ultimately, a second amount of particulate material may be deposited onto the adhesive  288 . 
     Further processing steps may be included to ultimately form pulpless absorbent cores  301 . For instance, in some embodiments, a top carrier sheet (not shown) may be applied over the second amount of particulate material. Additionally, a third adhesive zone  291  may be included where adhesive applicator  296  applies a third adhesive, adhesive  298  onto the second amount of particulate material, or, alternatively, onto the top carrier sheet before the top carrier sheet is applied to the second amount of particulate material. In still further embodiments, the resulting pulpless absorbent cores may be further processed, for example by delivery through a nip roller, or separation by a knife roll. Generally, any of the additional or alternative process steps described with respect to apparatus  20  may also be implemented with respect to apparatus  200 . 
     In further alternative embodiments, it should be understood that the pulpless absorbent cores contemplated by this disclosure are not limited to only two particulate material applications. For instance,  FIG. 8  depicts a generic pulpless absorbent core  101 ″ that may be formed according to the techniques disclosed herein and having any suitable number of particulate material applications. The pulpless absorbent core  101 ″ includes a base carrier sheet  140 , a top carrier sheet  145 , and a first amount of particulate material  150  and a second amount of particulate material  151 . The pulpless absorbent core  101 ″ further includes a first adhesive  152  and a second adhesive  153 . The adhesives  152 ,  153  and the first and second amounts of particulate material  150 ,  151  may be applied in a manner similar to that described with respect to apparatus  20  or  200 . 
     However, pulpless absorbent core  101 ″ may be formed from any suitable number of additional adhesive and particulate material applications. For instance, each pair of an additional application of adhesive and another amount of particulate material may be thought as a unit building up the absorbent core  101 ″. Accordingly, apparatus  20  or  200  may be modified to include additional adhesive application zone and particulate material delivery chamber units situated after second adhesive application zone  81  and particulate material delivery chamber  60   b  or adhesive application zone  281  and particulate material delivery chamber  260   b.  For each additional adhesive application zone and particulate material delivery chamber unit, pulpless absorbent core  101 ″ may include another adhesive and amount of particulate material. Although the pulpless absorbent core  101 ″ is contemplated to include any number of suitable additional units of adhesive and particulate material, as indicated by dots  156 , some example suitable number of adhesive and particulate material units include 3, 4, 5, 6, and 7. 
     As mentioned previously, in some embodiments, one or more masking members may be used in order to form shaped pulpless absorbent cores.  FIG. 9  depicts forming drum  26  including example masking members  160 , although similar masking members may be used with forming conveyer  226 . Masking members  160  mask portions of the forming surface  24 , creating a pattern of shaped un-masked areas of the forming surface  24 . These shaped un-masked areas will affect a distribution of particulate material within the resulting absorbent cores, thereby helping to create the shaped absorbent cores. 
     Although only shown with one example shape in  FIGS. 9 and 10 , in other suitable embodiments, the masking members  160  can have any number of different patterns. In still further embodiments, each of the masking members  160  can have different patterns and may be arranged in any order on the forming drum  26 . The illustrated system of masking members  160  in  FIG. 9  includes substantially identical masking members  160  arranged consecutively around the circumference of the forming drum  26 . The masking members  160  can be joined and assembled to the forming drum  26  and/or the forming surface  24  by employing any conventional attaching or mounting mechanisms. For example, the masking members  160  may be secured to the forming surface  24  by a plurality of bolts inserted through holes in the masking members  160  and the forming surface  24 . 
     The masking members  160  may have any shape suitable for mounting onto the forming surface  24 . For example, the masking members  160  may have an outer perimeter that forms a substantially rectangular shape. Additionally, the masking members  160  may have a slight curve along their length in the machine direction  54  to form an arc for fitting on the cylindrical forming surface  24 . In other suitable embodiments, the masking members  160  may be substantially flat for fitting on planar forming surfaces, such as the planer forming conveyer  226  of apparatus  200 . The curve of each masking member  160  may have a radius substantially equal to the radius of the forming surface  24  such that the masking members  160  fit on the forming surface  24 . When joined together, a series of masking members  160  can completely concentrically encircle the circumference of the forming surface  24 . 
       FIG. 10  depicts a close-up of one exemplary masking member  160  disposed over the forming surface  24 . As can be seen in  FIG. 10 , masking member  160  includes both masking end portions  162  and masking side portions  164 . Masking side portions  164  may extend along the masking member  160  for a distance  166 . Some example values of distance  166  may range from about 10 cm to about 30 cm. Additionally, masking side portions  164  may extend inward from the edges of the masking member  160  a distance  168 . Some example values of distance  168  may range from about 1 cm to about 5 cm. The masking side portions  164  may act to form a crotch region  170  in the resulting formed absorbent cores. 
     When the masking members  160  are used within the processes described with respect to apparatus  20  and apparatus  200 , the masking members  160  may affect a distribution of particulate material within a resulting absorbent core. As described previously, as the base carrier sheet travels around the forming drum  26 , the base carrier sheet may be drawn to the forming surface  24  by the use of a vacuum drawing air through forming surface  24  and into an interior of the forming drum  26 . Additionally, as the base carrier sheet travels through a particulate material delivery chamber, the particulate material may be drawn to the base carrier sheet by the vacuum. Where masking members  160  are used, the base carrier sheet travels around the forming drum  26  on top of the masking members  160 , which effectively block air moving through the forming surface  24  in the masked areas. 
     Accordingly, as the base carrier sheet travels through a particulate material delivery chamber, the particulate material will be drawn preferentially onto the base carrier sheet over the un-masked areas of the forming surface  24 . 
       FIG. 11  depicts example shaped absorbent cores  201  that may be formed using the masking members  160 . In the example of  FIG. 11 , different regions of the shaped absorbent cores  201  are shown with dashed lines. The shaped absorbent cores  201  may include regions of relatively higher average basis weights, such as within the crotch regions  170  and other regions where the forming surface  24  was un-covered by the masking members  160 . The shaped absorbent cores  201  may also include regions of relatively lower average basis weights, such as in end regions  171  and leg regions  173 . In embodiments contemplated by this disclosure, the areas of relatively higher average basis weights may have average basis weights ranging from between about 100 grams per meter (gsm) to about 1000 gsm. The areas of relatively lower average basis weights may have average basis weights ranging from between about 0 gsm to about 100 gsm. In some embodiments, the shaped absorbent cores  201  may be separated into individual shaped absorbent cores by cutting the length of resulting shaped absorbent cores  201  in the end regions  171 . 
     The shaped absorbent cores  201  formed using masking members, such as masking members  160 , may have some benefits over non-shaped absorbent cores. For instance, the regions of lower basis weights of particulate material may allow the shaped absorbent cores  201  to have a lower overall particulate material content than non-shaped cores, resulting in lower manufacturing costs. However, because of the locations of the areas of higher basis weights, overall absorption performance of the shaped absorbent cores  201  may be at least the same as corresponding non-shaped absorbent cores. 
     As mentioned previously, the pulpless absorbent cores of the present disclosure may be truly pulpless, or the pulpless absorbent cores may have a relatively small pulp content. For example, some of the pulpless absorbent cores of the present disclosure may include an amount of cellulose fibers that is between about 0.5% and about 10%, by weight, of the total contents of the cores. The addition of a small amount of cellulose fibers to the absorbent cores the present disclosure may impart a greater feeling of softness or provide other beneficial properties to the absorbent cores.  FIG. 12  depicts one example apparatus, apparatus  300 , which may be used to form the pulpless absorbent cores that have a small pulp content. 
     Apparatus  300  is very similar to apparatus  20  of  FIG. 1 . For instance, a base carrier sheet  370  may be fed onto forming drum  326 . The base carrier sheet  370  may then advance through a series of adhesive applications zone  380 ,  381  (and, possibly  391   a  or  391   b ) and particulate material delivery chambers  360   a,    360   b.  A top carrier sheet  375  may then be applied to form the resulting absorbent cores  399 . 
     One difference between apparatus  20  and apparatus  300  is that apparatus  300  may further include fiberizer  340 . In the embodiment of  FIG. 12 , the fiberizer  340  may be fed pulp or cellulose sheets and break up the cellulose sheets into many individual fibers. The fiberizer  340  may be a hammer mill-type fiberizer, or any other suitable type of fiberizer known in the art. The cellulose fibers may exit the fiberizer  340  into delivery ducts  341  and  342 . The delivery ducts may ultimately form material delivery chambers  360   a,    360   b.    
     The material delivery chambers  360   a,    360   b  may differ from the particulate material delivery chambers  60   a,    60   b  of apparatus  20  in that the material delivery chambers  360   a,    360   b  may deliver both particulate material and cellulose fibers to the base carrier sheet. For example, cellulose fibers may travel through the delivery ducts  341 ,  342  and enter the material delivery chambers  360   a,    360   b.  Gravity, along with the vacuum pressure within the material delivery chambers  360   a,    360   b  will cause the cellulose fibers to deposit onto the base carrier sheet  370 . 
     Particulate material may also be delivered to the material delivery chambers  360   a,    360   b.  For instance, particulate material may be stored in hopper  390  and may be delivered to the material delivery chambers  360   a,    360   b  through delivery pipes  364 ,  366 . The delivery pipes  364 ,  366  may ultimately form particulate material delivery conduits  362   a,    362   b  within the material delivery chambers  360   a,    360   b.  The delivered particulate material may exit the particulate material delivery conduits  362   a,    362   b  within the material delivery chambers  360   a,    360   b.  Similar to the pulp fibers, gravity and the vacuum pressure within the material delivery chambers  360   a,    360   b  will cause the particulate material to be deposited onto the base carrier sheet  370 . In this manner, apparatus  300  may be used to form pulpless absorbent cores containing an amount of cellulose fibers representing between about 0.5% and about 10% of the total weight of the materials within the pulpless absorbent cores. 
       FIG. 13  depicts a cross-section of an example absorbent core  399  that may be formed by the apparatus  300 .  FIG. 13  depicts absorbent core  399  including base carrier sheet  370  and top carrier sheet  375 . Absorbent core  399  also includes adhesives  378  and  388 , represented by ‘x’s and ‘w’s, respectively. In general, the absorbent core  399  may be similar to, and may be formed similarly to, the other absorbent cores of the present disclosure, such as absorbent cores  101 ,  101 ′, and  101 ″. Unlike the previous absorbent cores, however, absorbent core  399  further includes cellulose fibers  393   a,    393   b.  As can be seen, cellulose fibers  393 ,  393   b  are disposed intermixed with the individual particulate material particles  389 . Cellulose fibers  393   a  may be deposited, for instance, along with a first amount of particulate material particles  389 , such as in particulate material delivery chamber  360   a  of  FIG. 12 . Cellulose fibers  393   b  may be deposited, for instance, along with a second amount of particulate material particles  389 , such as in particulate material delivery chamber  360   b  of  FIG. 12 . As mentioned previously the addition of cellulose fibers may impart a greater softness to absorbent cores of the present disclosure, and the cellulose fibers may further help to stabilize the particulate material particles  389  between the base carrier sheet  370  and the top carrier sheet  375 . 
     Again, it should be understood that  FIG. 12  only represents one contemplated embodiment. In further embodiments, apparatuses  20  and/or  200  may be modified to include only a single particulate material delivery chamber that further intermixes cellulose fibers with the particulate material before deposition at a forming surface, instead of the two shown with respect to  FIG. 12 . In general, the apparatuses  20  and/or  200  may include a number of particulate material delivery chambers that allow for the intermixing of cellulose fibers and particulate material that is less than all of the particulate material delivery chambers of the apparatuses. In these alternative embodiments, then, a relatively smaller proportion of the formed absorbent cores may include cellulose fibers. For instance, if the cellulose fibers were intermixed with a first amount of particulate material, the mixture of cellulose fibers and particulate material may be located proximate the base carrier sheet. However, if the cellulose fibers were intermixed with a second (or third, fourth, etc.) amount of particulate material, the mixture of cellulose fibers and particulate material may be located closer to the top carrier sheet than the first amount of particulate material. 
     In alternative embodiments, instead of forming the pulpless absorbent cores of the present disclosure with both a base carrier sheet and a top carrier sheet, as described previously, some contemplated methods may only use a single carrier sheet.  FIGS. 14A and 14B  depict example embodiments where a single carrier sheet may be used instead of both a base carrier sheet and a top carrier sheet. 
       FIG. 14A  depicts carrier sheet  405 . In some embodiments, carrier sheet  405  may have a first edge region  402  having a first edge  403  and a second edge region  406  having a second edge  407 , with a middle region  404  disposed between the first edge region  402  and the second edge region  406 . In the embodiment of  FIG. 14A , particulate material and adhesive may only be applied within the middle region  404 . After application of adhesive and particulate material, instead of applying a second carrier sheet as described herein previously, the second edge region  406  may be folded over the middle region  404  and onto the first edge region  402  such that the second edge  407  is disposed proximate the first edge  403 . The edges  403 ,  407  may then be bonded together to create an enclosed pulpless absorbent core. Bonding the edges  403  and  407  together may be done by any suitable method, such as by pressure bonding, adhesive bonding, ultrasonic bonding, or the like. The apparatuses described herein may be modified to produce such pulpless absorbent cores. For instance, instead of machinery to apply the top carrier sheets, the apparatuses described herein may include folding and bonding machinery, which are well known in the art, to fold the second edge region  406  onto the first edge region  402  and to bond the regions  402 ,  406  together. 
     In some embodiments according to  FIG. 14A , the carrier sheet  405  may have a width  410 . Width  410  may be greater than twice the width of a forming surface used to create pulpless absorbent cores, or alternatively greater than twice the width of an un-masked portion of a forming surface used to create pulpless absorbent cores. In some specific examples, width  410  may range between about 25 cm and about 60 cm. 
     The middle region  404  may have a width  412 . The width  412  may range from between about 40% to about 50% of the overall width  410  of the carrier sheet  405 . Additionally, the first edge region  402  may have a width  414  that is be between about 0.5% and about 10% of the overall width  410  of the carrier sheet  405 . 
       FIG. 14B  depicts another example embodiment of a single carrier sheet that may be used to form the pulpless absorbent cores of the present disclosure. In the example of  FIG. 14B , the carrier sheet  450  may have an overall width  460 . The overall width  460  may have values similar to those described with respect to width  410 . Additionally, the carrier sheet  450  may have a first edge region  452 , a middle region  454 , and a second edge region  456 . As with the embodiment of  FIG. 14A , adhesive and particulate material may only be applied to the carrier sheet  450  within the middle region  454 . After application of adhesive and particulate material to the middle region  454 , one of the first edge region  452  or the second edge region  456  may be folded over onto the middle region  454 . Then, the other of the first edge region  452  or the second edge region  456  may be folded over the middle region  454 . In some embodiments, the edge regions  452 ,  456  may overlap over the middle region  454 , and at least a portion of each of the first edge region  452  and the second edge region  456  may be bonded together to form an enclosed pulpless absorbent core. 
     Similarly to carrier sheet  405 , in some embodiments the width  460  of the carrier sheet  450  may be greater than twice the width of a forming surface used to create pulpless absorbent cores, or greater than an un-masked portion of a forming surface used to create pulpless absorbent cores. However, this is not necessary in all embodiments. In at least some embodiments, width  460  may range between about 25 cm and about 60 cm. 
     The region  454  of the carrier sheet  450  may have a width  462 . The width  462  may range from between about 33% to about 50% of the overall width  460  of the carrier sheet  450 . In some embodiments, each of the first edge region  452  and the second edge region  456  may have a width (not shown) that is between about 25% and about 33% of the overall width  460 . However, the widths of the first edge region  452  and the second edge region  456  do not necessarily need to be equal. For example, the width of the first edge region  452  may be between about 35% and about 40% of the overall width  460  and the width of the second edge region  456  may be between about 10% and about 25% of the overall width of  460 , or vice versa. 
       FIG. 15  depicts yet another exemplary particulate material delivery chamber that may be used in place of any of the particulate material delivery chambers described herein.  FIG. 15  further depicts a forming drum  26 ′ having a forming surface  24 ′ and a particulate material inlet  61   a ′ having an inlet width  112 ′ less than the width of the forming surface  24 ′ of the forming drum  26 ′. Specifically,  FIG. 15  depicts a front view of exemplary particulate material delivery chamber  60   a ′ and forming drum  26 ′. As can be seen, the forming drum  26 ′ may have a drum width  111 ′, and the forming surface  24 ′ may have a forming surface width  110 ′. In such embodiments, the forming surface width  110 ′ may relate to the width of the unmasked portion of the forming surface  24 ′, e.g. the width of the absorbent core region  185 . Generally, the drum width  111 ′ will be greater than the forming surface width  110 ′, as the forming drum  26 ′ will include drum rim  52 ′. The exemplary particulate material delivery chamber  60   a ′ including particulate material delivery conduit  62   a ′ may be used in the processes described with respect to  FIGS. 1 and/or 7 . For instance, the specific configuration shown with respect to particulate material delivery chamber  60   a ′ may be used for particulate material delivery chamber  60   a  (or particulate material delivery chamber  260   a ), particulate material delivery chamber  60   b  (or particulate material delivery chamber  260   b ), or both. 
     As described previously, in some embodiments, and as shown in  FIG. 15 , forming drum  26 ′ may include one or more masking members  183  disposed over the forming surface  24 ′. Masking member  183  may include masking portions  184   a  and  184   b.  The unmasked portion of the forming surface  24 ′ may represent an absorbent core region  185 . The absorbent core region  185  may be split into a central region  186  having a central region width, a left edge region  187  having a left edge region width, and a right edge region  188  having a right edge region width. The widths of the different regions  186 ,  187 , and  188  are described below with respect to  FIGS. 16 and 17  depicting example absorbent cores. 
     Where the masking member  183  includes masking portions such as masking portions  184   a,  the width of the absorbent core region  185  of the forming surface  24 ′ may differ depending on where on the forming surface  24 ′ the width measurement is taken. For instance, in the example of  FIG. 15 , the forming surface width  110 ′ may relate to a greatest width of the absorbent core region  185 , whereas the forming surface width  180  may relate to the smallest width of the absorbent core region  185 . 
     Also shown in  FIG. 15  is the particulate material delivery conduit  62   a ′ and the inlet  61   a ′ having an inlet width  112 ′. As shown, the inlet width  112 ′ may be generally less than the forming surface width  110 ′. In some specific contemplated embodiments, the inlet width  112 ′ may generally be less than the forming surface width  110 ′, but may be greater than or equal to the forming surface width  180 . However, in still other embodiments, the inlet width  112 ′ may be less than both the forming surface width  110 ′ and the forming surface width  180 . In still more specific embodiments, the inlet width  112 ′ may have a value that is between about 25% and about 75% of the value of the greatest forming surface width, e.g. forming surface width  110 ′. In more specific embodiments, the inlet width  112 ′ may have a value that is between about 33% and about 66% of the value of the forming surface width  110 ′. In other embodiments, the inlet width  112 ′ may have a value that is between about 50% and about 150% of the value of the smallest forming surface width, e.g. forming surface width  180 . Some example values for the inlet width  112 ′ range between about 5 cm and about 20 cm. 
     The particulate material delivery conduit  62   a ′ may further have a vertical conduit spacing  114 ′ comprising an amount of space between the inlet  61   a ′ of the particulate material delivery conduit  62   a ′ and the forming surface  24 ′. The vertical conduit spacing  114 ′ may be between about 15 cm and about 100 cm. 
     Additionally, in some further embodiments, the particulate material delivery chamber  60   a ′ may not be sealed against the forming drum  26 ′. For instance, there may be a gap between the bottom edges  113 ′ of the particulate material delivery chamber  60   a ′ and the forming surface  24 ′ or the forming drum  26 ′, represented by gap space  116 ′. However, in other embodiments, the particulate material delivery chamber  60   a ′ may be sealed against the forming drum  26 ′ to close gap space  116 ′, or one or more members (not shown) may be disposed about the forming drum  26 ′, either internally or externally to the particulate material delivery chamber  60   a ′, in order to seal gap space  116 ′. Suitable values for gap space  116 ′ may be similar to those described previously with respect to  FIG. 4B . 
     Accordingly, in some embodiments, there may be airflow into the particulate material chamber  60   a ′ through gap space  116 ′ between the bottom edges  113 ′ of the particulate material delivery chamber  60   a ′ and the forming surface  24 ′ or the forming drum  26 ′, as shown by arrows  117 ′. Entry of air into the particulate material delivery chamber  60   a ′ may push the particulate material  89 ′ toward a center of the forming surface  24 ′ as the particulate material falls from the inlet  61   a ′ to the forming surface  24 ′. This may result in a cross-direction  56  width of the particulate material  89 ′ deposited at the forming surface that is less than the cross-direction  56  width that the particulate material  89 ′ would have had if there was no airflow through gap space  116 ′. Or, alternatively, the cross-direction  56  width of the particulate material  89 ′ deposited at the forming surface  24 ′ may be the same, but relatively less overall particulate material  89 ′ may be deposited toward the edges of the forming surface  24 ′. 
     However, where there is no gap space  116 ′, there may be no air impinging on the stream of particulate material  89 ′ and pushing the particulate material  89 ′ inward from the edges of the forming surface  24 ′. In these embodiments, the cross-direction  56  width of the particulate material deposited at the forming surface  24  may be greater than the cross-direction  56  width that the particulate material  89 ′ would have had if there was airflow through gap space  116 ′. Or, alternatively, the cross-direction  56  width of the particulate material  89 ′ deposited at the forming surface  24 ′ may be the same, but relatively more overall particulate material  89 ′ may be deposited toward the edges of the forming surface  24 ′. 
     In some additional or alternative embodiments, an upper region of the particulate material delivery chamber  60   a ′ may be open and may allow air to flow into the particulate material delivery chamber  60   a ′ as shown by arrows  119 ′. In these embodiments, the inflow of air may cause the particulate material  89 ′ to fall toward the forming surface  24 ′ in a more linear path. For instance, as air enters the particulate material delivery chamber  60   a ′, the air may be pulled toward the forming surface  24 ′ by the vacuum pressure in the chamber  60   a ′, and may travel in a generally linear manner. The air may pull the particulate material  89 ′ toward the forming surface  24 ′, and the location of the particulate material  89 ′ deposited at the forming surface may be more heavily influenced by individual starting positions of the particulate material  89 ′ at the inlet  61   a ′. In these embodiments, the cross-direction  56  width of the particulate material deposited at the forming surface  24  may be lesser than the cross-direction  56  width that the particulate material  89 ′ would have had if there was no airflow entering through the top of the particulate material delivery chamber  60   a ′. Or, alternatively, the cross-direction  56  width of the particulate material  89 ′ deposited at the forming surface  24 ′ may be the same, but relatively less overall particulate material  89 ′ may be deposited toward the edges of the forming surface  24 ′. 
     However, in still other additional or alternative embodiments, an upper region of the particulate material delivery chamber  60   a ′ may be sealed and may prevent air from entering the particulate material delivery chamber  60   a ′. In these embodiments, the air within the particulate material delivery chamber  60   a ′ may be more turbulent than in the embodiments where the upper region of the particulate material delivery chamber  60   a ′ allows entry of air, as represented by arrows  121 ′. In these embodiments, the relatively greater turbulence may cause the particulate material  89 ′ to fall in much less linear paths and, therefore, the location of the particulate material  89 ′ deposited at the forming surface  24 ′ may be less dependent on their initial starting position at the inlet  61   a ′ than where the upper region of the particulate material delivery chamber  60   a ′ is open to the air. This configuration may result in the cross-direction  56  width of the particulate material deposited at the forming surface  24  being greater than the cross-direction  56  width that the particulate material  89 ′ would have had if there was airflow entering through the top of the particulate material delivery chamber  60   a ′. Or, alternatively, the cross-direction  56  width of the particulate material  89 ′ deposited at the forming surface  24 ′ may be the same, but relatively more overall particulate material  89 ′ may be deposited toward the edges of the forming surface  24 ′. 
     One of the features of the particulate material delivery chamber  60   a ′ disclosed in  FIG. 15  is the ability to preferentially distribute the particulate material  89 ′ exiting the inlet  61   a ′ toward a central region of the forming surface  24 ′. For instance, as described in the embodiment of  FIGS. 4A and 4B , the particulate material  89 ′ may exit the inlet  61   a ′ at less than 1200 meters per minute (m/min), less than 900 m/min, less than 600 m/min, or less than 300 m/min. At these speeds, as the vacuum draws the particulate material  89 ′ toward the forming surface  24 ′, the vacuum can impact the cross-machine direction  56  spread of the particulate material  89 ′ as it is deposited at the forming surface  24 ′. For instance, as can be seen in  FIG. 15 , particulate material  89 ′ exiting the inlet  61   a ′ may follow different paths towards the forming surface  24 ′. A portion of the particulate material  89 ′ may follow a relatively straight path from the inlet  61   a ′ toward the forming surface, such as the particulate material  89 ′ shown directly below the particulate material delivery conduit  62   a ′. However, other portions of the particulate material  89 ′ may follow paths that extend beyond the inlet  61   a ′ in the cross-machine direction  56 , such as the particulate material  89 ′ shown in regions  181  and  182 . For these portions of the particulate material  89 ′, the vacuum diverges the particulate material  89 ′ exiting the inlet  61   a ′ in the cross-machine direction  56 . 
     Accordingly, the particulate material  89 ′ deposited onto the forming surface  24 ′ may be preferentially deposited into the central region  186  of the absorbent core region  185 . In some contemplated embodiments, the central region  186  of the absorbent core region  185  may have an average basis weight of particulate material  89 ′ that is greater than 100% of the average basis weight of the particulate material  89 ′ in the left edge region  187  and/or the right edge region  188 . In more specific examples, the central region  186  of the absorbent core region  185  may have an average basis weight of particulate material  89 ′ that is about 100%, about 110%, about 120%, about 130%, about 140%, or about 150%, or any other suitable percent, of the average basis weight of the particulate material  89 ′ in the left edge region  187  and/or the right edge region  188 . 
     The specific configuration of the particulate material delivery chamber  60   a ′ and the vacuum within the forming drum  26 ′ may be tuned to produce desired amounts of the particulate material  89 ′ being deposited in the central region  186  of the absorbent core region  185 . For instance, the specific inlet width  112 ′ and the strength of the vacuum may be chosen to produce the desired amounts of the particulate material  89 ′ being deposited in the central region  186  of the absorbent core region  185 . In general, the vacuum may vary in strength between about 2 inches of H 2 0 to about 40 inches of H 2 0. 
     In some further additional or alternative embodiments, the strength of the vacuum may be varied to produce different desired amounts of the particulate material  89 ′ being deposited in the central region  186  of the absorbent core region  185 . For instance, the strength of the vacuum may be varied to produce narrower or wider distributions of the particulate material  89 ′ as desired. Producing narrower or wider distributions may also be achieved by adjusting the inlet width  112 ′. In even further embodiments, the vacuum may be varied throughout forming of each individual absorbent core to produce varying amounts of the particulate material  89 ′ deposited onto the central region  186  of the absorbent core region  185  along a machine direction length of an individual absorbent core. 
       FIG. 16  depicts an example absorbent core  220  that may be formed according to the apparatus disclosed in  FIGS. 1, 7 , and/or  12  and  15 . The absorbent core  220  may have been formed, for example, without masking members, or with masking members that defined a rectangular unmasked portion of the forming surface. Absorbent core  220  may have a similar structure as example absorbent cores  101 ,  101 ′,  101 ″,  201 , and/or  399 . Absorbent core  220  may have a central longitudinal axis  221  that may correspond to machine direction  54  when absorbent core  220  is being formed on the applicable forming apparatus. The absorbent core  220  may also be divided into three regions: central region  226  having central region width  230 , left edge region  227  having left edge region width  231 , and right edge region  228  having right region edge width  232 . In some embodiments, the central region width  230  may be between about 50% and about 75% of the overall core width  235 . Accordingly, the left edge region width  231  and the right edge region width  232  may each comprise between about 12.5% and about 25% of the overall core width  235 . In more specific embodiments, the central region width  230  may be between about 62% and about 67% of the overall core width  235 . In these embodiments, the left edge region width  231  and the right edge region width  232  may each comprise between about 16.5% and about 19% of the overall core width  235 . It should be understood, however, that the left edge region width  231  and the right edge region width  232  do not need to be equal in all contemplated embodiments. Rather, the left edge region width  231  may be either greater or lesser than the right edge region width  232  in different contemplated embodiments. Additionally, these relative width values may be the same for the corresponding regions  186 ,  187 , and  188  of the absorbent core region  185  described with respect to  FIG. 15 . 
     Additionally, as absorbent core  220  was formed using the apparatus and methods described with respect to  FIG. 15 , the regions  226 ,  227 , and  228  may have amounts of particulate material in each region similar to the amounts of particulate material described above with respect to absorbent core region  185  and  FIG. 15  being deposited at the forming surface  24 ′. For instance, in some embodiments, the central region  226  of the absorbent core  220  may have an average basis weight of particulate material that is greater than 100% of the average basis weight of particulate material in the left edge region  227  and/or the right edge region  228 . In more specific examples, the central region  226  of the absorbent core  220  may have an average basis weight of particulate material that is about 100%, about 110%, about 120%, about 130%, about 140%, or about 150%, or any other suitable percent, of the average basis weight of the particulate material in the left edge region  227  and/or the right edge region  228 . In some even further embodiments, a concentration of particulate material in the absorbent core  220  may generally decrease along a path from the central longitudinal axis  221  toward edges  233  and  234  of the absorbent core  220 , or along a path from the boundary of the central region  226  and left edge region  227  or right edge region  228  toward edge  233  or edge  234 , respectively. 
       FIG. 17  depicts another example absorbent core  240  that may be formed according to the apparatus disclosed in  FIGS. 1, 7 , and/or  12  and  15 . In this embodiment, however, the absorbent core  240  may have formed using masking members, such as a masking member  183  depicted in  FIG. 15 . 
     Absorbent core  240  may have a similar layered structure as example absorbent cores  101 ,  101 ′,  101 ″,  201 , and/or  399 . Absorbent core  240  may have a central longitudinal axis  241  that may correspond to machine direction  54  when absorbent core  240  is being formed on the applicable forming apparatus. The absorbent core  240  may also be divided into three regions: central region  246  having a central region width  250 , left edge region  247 , and right edge region  248 . Due to the shaped nature of the absorbent core  240 , unlike absorbent core  220 , absorbent core  240  may have multiple edge widths. For example, absorbent core  240  may have left edge region widths  251   a,    251   b,  and  251   c.  Left edge region width  251   a  may represent the largest left edge region width while left edge region width  251   c  may represent the smallest left edge region width. Likewise, absorbent core  240  may have right edge region widths  252   a,    252   b,  and  252   c,  with right edge region width  252   a  representing the largest right edge region width and right edge region width  252   c  representing the smallest right edge region width. 
     In some embodiments, the absorbent core  240  may be truly shaped in that the absorbent core  240  may have the contoured outer shape as shown in  FIG. 17 . In other embodiments, however, the absorbent core  240  may be shaped but may not have a contoured outer shape. For instance, the absorbent core  240  may still have material disposed within regions  255  and  256  to form a rectangular outer shape. When the absorbent core  240  was being formed, regions  255  and  256  may have been disposed over masking portions of a masking member. Accordingly, in these embodiments, the regions  255  and  256  may have relatively low particulate material content, or no particulate material at all, as the vacuum of the forming drum in the regions  255  and  256  would have been blocked by the masking member. The particulate material exiting the inlet of the particulate material conduit would have been drawn by the vacuum of the forming drum toward the unmasked portions of the forming surface  24 ′, thereby creating higher concentrations of the particulate material in regions of the absorbent core  240  other than regions  255  and  256 . 
     In some embodiments, the central region width  250  may be between about 50% and about 75% of the overall core width  245 . Accordingly, the left edge region width  251   a  and the right edge region width  252   a  may each comprise between about 12.5% and about 25% of the overall core width  245 . In more specific embodiments, the central region width  250  may be between about 62% and about 67% of the overall core width  245 . In these embodiments, the left edge region width  251   a  and the right edge region width  252   a  may each comprise between about 16.5% and about 19% of the overall core width  245 . Even further, in some embodiments, the central region  246  may extend across the core  240  such that the values of widths  251   c,    252   c  are zero. It should be understood, however, that the left edge region width  251   a  and the right edge region width  252   a  do not need to be equal in all contemplated embodiments. Rather, the left edge region width  251   a  may be either greater or lesser than the right edge region width  252   a  in different contemplated embodiments. 
     In other embodiments, the relative widths of central region  246  and left edge region  247  and right edge region  248  may be measured based on the smallest widths of the left edge region  247  and the right edge region  248 . For instance, the left edge region width  251   c  and the right edge region width  252   c  may each comprise between about 12.5% and about 25% of the overall core width  245 . In more specific embodiments, the left edge width region  251   c  and the right edge region width  252   c  may each comprise between about 16.5% and about 19% of the overall core width  245 . Again, it is not necessary that these widths  251   a,    252   a  be equal to each other in all embodiments. Also, any of these relative widths may be the same as or similar to the relative widths of the regions  186 ,  187 , and  188  of the absorbent core region  185  described with respect to  FIG. 15 . 
     Additionally, as absorbent core  240  was formed using the apparatus and methods described with respect to  FIG. 15 , the regions  246 ,  247 , and  248  may have amounts of particulate material in each region similar to the particulate material amounts described above with respect to absorbent core region  185  and  FIG. 15  being deposited at the forming surface  24 ′. For instance, in some embodiments, the central region  246  of the absorbent core  240  may have an average basis weight of particulate material that is greater than 100% of the average basis weight of particulate material in the left edge region  247  and/or the right edge region  248 . In more specific examples, the central region  246  of the absorbent core  240  may have an average basis weight of particulate material that is about 100%, about 110%, about 120%, about 130%, about 140%, or about 150%, or any other suitable percent, of the average basis weight of the particulate material in the left edge region  247  and/or the right edge region  248 . In some even further embodiments, a concentration of particulate material in the absorbent core  240  may generally decrease along a path from the central longitudinal axis  241  toward edges  253  and  254  of the absorbent core  240 , or along a path from the boundary of the central region  246  and left edge region  247  or right edge region  248  toward edge  253  or edge  254 , respectively. 
       FIG. 18  depicts exemplary masking member  700  that may be used in conjunction with any of the above described processes to produce absorbent cores. For example, masking member  700  may be similar to masking member  160  of  FIG. 10 , and may be used in a similar manner to masking member  160 . Multiple masking members  700  may be attached to a forming drum or conveyer system, such as those described with respect to apparatuses  20  and  200 , to mask portions of a foraminous forming surface. The multiple masking members  700  may be attached end to end to allow formation of a continuous length of absorbent cores. In some further embodiments, masking member  700  may comprise opposing masking portions  700   a  and  700   b.  Although, in some embodiments, masking member  700  may further comprise masking portions  702  and/or  703  depicted by dashed lines in  FIG. 18 , disposed at either ends of masking member  700  to form some separation between adjacent masking members  700 . 
     Generally, when masking member  700  is disposed over a foraminous forming surface, masking member  700 , which is made from a non-foraminous material, may block portions of the foraminous forming surface, thereby defining an absorbent core region on the forming surface. The absorbent core region may then be the un-masked foraminous portions of the foraminous forming surface. An exemplary absorbent core region shape  701  is depicted in  FIG. 18  by a hatching pattern. In some embodiments, the absorbent core region  701  may comprise a rear core region  706  and a front core region  708 . In these embodiments, each of the rear core region  706  and the front core region  708  may span half of overall length  717  of the absorbent core region  701 . 
     In other embodiments, the absorbent core region  701  may additionally comprise crotch region  707 . In some of these embodiments, each of the rear core region, the crotch region, and the front core region may span a third of overall length  717  of the absorbent core  701 . Some example suitable values for the overall length  717  of the absorbent core region  701  range between about 10 cm and about 50 cm. In other of these embodiments, rather than be defined as a middle third of the absorbent core region  701 , the crotch region  707  may be defined as the region bounded by shaped regions  705   a,    705   b.  For instance, in the example of  FIG. 18 , the crotch region  707  may span a length  714   a  or  714   b  in the machine direction  754 , which correspond to a length of the shaped regions  705   a,    705   b  within the absorbent core region  701 . Example values for lengths  714   a  and  714   b,  defining a length of shaped regions  705   a  may range between about 10 cm and about 30 cm. Additionally, shaped regions  705   a,    705   b  may extend inward from the greatest cross-machine direction widths  710 ,  711  for a width  713   a,    713   b.  Example suitable values for widths  713   a,    713   b  may range between about 1 cm and about 10 cm. This may put a smallest cross-machine direction width  712  of the crotch region  707  between about 5 cm and about 25 cm. Accordingly, widths  713   a,    713   b  may have values that are between about 5% and about 40% of the greatest cross-machine direction widths  710 ,  711 . 
     Further, as shown in  FIG. 18 , the shaped regions  705   a,    705   b  may have an arcuate shape. However, this is only an example. Generally, the shaped regions  705   a,    705   b  may have any suitable shape. For instance, the shaped regions  705   a,    705   b  may have any suitable shape where the area of the shaped regions  705   a,    705   b  ranges between about 25% and about 50% of an area defined by the greatest cross-machine direction width  710  or  711 , and the overall length  717 . 
     The absorbent core region  701  may be divided up into a number of different regions running a length of the absorbent core region  701 . One such region may include central region  726  having a width  709  running in the cross-machine direction  756 , shown as extending between dashed lines  725   a,    725   b  in  FIG. 18 . In some embodiments, the central region width  709  may be coextensive with the smallest cross-machine direction width  712 . However, in other embodiments, the central region width  709  may be smaller or greater than the smallest cross-machine direction width  712 . The absorbent core region  701  may further include a first edge region  727  having a first edge region width  718   a  and a second edge region  728  having a second edge region width  718   b.  The absorbent core region  701  may further include rear ear regions  719   a,    719   b  and front ear regions  719   cb,    719   d.  The rear ear regions  719   a,    719   b  may be defined as regions above the shaped portions  705   a,    705   b  and outside of the central region  726 . Likewise, the front ear regions  719   c,    719   d  may be defined as regions below the shaped portions  705   a,    706   b  and outside of the central region  726 . 
     Where masking member  701  includes shaped portions  705   a,    705   b  defining the crotch region  707 , the lengths of the rear core region  706  and the front core region  708 , then, may be defined by lengths  716  and  715 , respectively. Some exemplary values for lengths  716  and  715  may range between about 1 cm and about 15 cm for length  716  and between about 1 cm and about 15 cm for length  715 . Each of the rear core region  706  and the front core region  708  may additionally extend in a cross-machine direction identified by widths  710  and  711 , respectively. Although generally shown as rectangular, the rear core region  706  and front core region may curved or have any suitable shape. In these cases, then, widths  710  and  711  may represent the greatest cross-machine width of each of the rear core region  706  and the front core region  708 . Example suitable values for widths  710  and  711  may range from between about 7 cm and about 30 cm. 
     In some embodiments, masking portions  700   a  and  700   b  may have widths  704   a,    704   b.  In some embodiments, widths  704   a,    704   b  may be coextensive with a width of the drum rim where masking member  700  is attached to a forming drum so as to not block the foraminous forming surface except in the areas of the shaped portions  705   a,    705   b.  However, in other embodiments, widths  704   a,    704   b  may be large enough to extend beyond the drum rim and over at portion of the foraminous forming surface. 
     Generally, masking members such as masking members  700  may be used to form absorbent cores having differing average basis weights within different regions of the absorbent cores. For instance, the masking members  700  may block airflow through the foraminous forming surface. This blocking of airflow may cause the particulate material exiting a particulate material delivery conduit to deposit onto the foraminous forming surface at different rates. This process is described in more detail below with respect to  FIGS. 19A and 19B . 
       FIG. 19A  depicts a perspective view internal to exemplary particulate material delivery chamber  760 . As can be seen, particulate material delivery chamber  760  includes particulate material delivery conduit  762  terminating with inlet  761 . Additionally, foraminous forming surface  724  is shown disposed between drum rims  752  and under base carrier sheet  770 . Foraminous forming surface  724  is also shown as including absorbent core regions  721   a - c.  The absorbent core regions  721   a - c  may be defined, for instance, by non-foraminous masking members, such as masking member  700  described with respect to  FIG. 18 . 
     The base carrier sheet  770  is shown disposed over the foraminous forming surface  724  and over the absorbent core regions  721   a - c.  The regions of the base carrier sheet  770  disposed over the absorbent core regions  721   a - c  may form base carrier sheet absorbent core regions  723   a - c.  Each of the base carrier sheet absorbent core regions  723   a - c  may be split into a base carrier sheet rear core region  732  and a base carrier sheet front core region  736 , which may correspond to the underlying front core region and rear core region of a respective absorbent core region  721   a - c.  In examples where the absorbent core regions  721   a - c  further include a crotch region, the base carrier sheet absorbent core regions  723   a - c  may also further include a base carrier sheet crotch region  734  disposed between the base carrier sheet rear core region  732  and the base carrier sheet front core region  736 . As can be seen in  FIG. 16A , the base carrier sheet front core region  736  trails the base carrier sheet rear core region  732  in the machine direction  754 . 
       FIG. 19A  also depicts particulate material being deposited onto the base carrier sheet  770 . For instance,  FIG. 19A  depicts individual particulate material  789  located within the base carrier sheet absorbent core region  723   a  and within a portion of the base carrier sheet absorbent core region  723   b.  Arrows  722   a  and  722   b  depict paths that particulate material  789  may follow upon exiting inlet  761  before depositing onto the base carrier sheet  770 . 
     As the forming drum carrying the forming surface  724  and the one or more masking members underlying the base carrier sheet  770  moves in the machine direction, different portions of the forming surface  724  will pass under the particulate material delivery conduit  762 . In embodiments where the underlying masking member or members include shaped regions, such as shaped regions  705   a,    705   b  described with respect to masking member  700 , a varying amount of un-masked surface area of the forming surface  724  will pass under the inlet  761 . 
     In these embodiments, where relatively smaller un-masked areas of the forming surface  724  and relatively greater un-masked areas of the forming surface  724  pass under the inlet  761 , the vacuum pulling air and the particulate material toward the forming surface  724  may affect an amount of the particulate material  789  deposited onto the base carrier sheet  770 . For example, as the relatively smaller un-masked areas of the forming surface  724 , such as the base carrier sheet crotch regions  724 , traverse under the inlet  761 , the shaped regions may block airflow through a portion of the forming surface  724 . This airflow blocking alters how the falling particulate material deposits onto the base carrier sheet  760 . As can be seen in  FIG. 19A , where the narrower regions of the absorbent core region  723   b  pass under the inlet  761 , the particulate material  789  may follow paths  722   a  which represent paths where the particulate material  789  falls and/or is pulled, toward the forming surface  724  at a relatively slower velocity. Where the wider regions of the absorbent core region  723   b  pass under the inlet  761 , the particulate material  789  may follow paths  722   b,  which represent paths where the particulate material  789  falls and/or is pulled, toward the forming surface  724  at a relatively faster velocity. These distinctions in the velocity at which the particulate material  789  falls and/or is pulled, toward the forming surface  724  may be particularly distinct when introducing the particulate material  789  into the chamber  760  at relatively low velocities, such as the velocities described previously with respect to the processes  20 ,  200 , and the other disclosed processes. 
     As the base carrier sheet  770  continues in the machine direction  754 , as can be seen in  FIG. 19B , the particulate material  789  that followed the paths  722   a,  rather than being deposited within the base carrier sheet crotch region  734  on top of the masked areas is instead deposited within either the base carrier sheet front core region  736  of the base carrier sheet absorbent core region  723   b  or within the un-masked areas of the crotch region  724 . Additionally, as the relatively greater un-masked area of the forming surface  724  of the base carrier sheet front core region  736  passes under the inlet  761  in  FIG. 19B , particulate material  789  exiting the inlet  761  falls and/or is pulled toward the forming surface  724  in both the base carrier sheet front core region  736  of the base carrier sheet absorbent core region  723   b  and the base carrier sheet rear core region  732  of the base carrier sheet absorbent core region  723   c.    
     Ultimately, this shifting of the falling particulate material  789  may cause the base carrier sheet front core region  736  of the base carrier sheet absorbent core region  723   b  to have a higher average basis weight than the base carrier sheet rear core region  732  of the base carrier sheet absorbent core region  723   c.  Additionally, in at least some embodiments, the base carrier sheet crotch region  734  may have a higher average basis weight than the base carrier sheet rear core region  732 . Further details about the relative basis weights of the different regions of the absorbent cores produced by the disclosed processes are discussed in more detail with respect to the following figures. 
       FIG. 20  depicts a strip of connected absorbent cores  740  that may be formed using any of the processes described herein and including one or more masking members as described with respect to  FIG. 18 . The strip of connected absorbent cores  740  shown in  FIG. 20  include individual, connected absorbent cores  750   a - c.  At a later process step, the individual, connected absorbent cores  750   a - c  may be separated to form individual, separated absorbent cores for use in absorbent articles. 
       FIG. 20  also shows absorbent core  750   b  broken down into different regions. For instance, absorbent core  750   b  depicts rear core region  706 ′, crotch region  707 ′, and front core region  708 ′.  FIG. 20  further depicts central region  726 ′, first edge region  727 ′, and second edge region  728 ′.  FIG. 20  additionally includes rear ear regions  719   a ′,  719   b ′ and front ear regions  719   c ′,  719   d ′. Dimensions including crotch region length  741 , rear core region length  746 , front core region length  743 , first shaped region width  744 , second shaped region width  745 , and crotch region width  742  are all also shown in  FIG. 20 . These regions and dimensions may generally align with the similar regions and dimensions defined with respect to the absorbent core region  701  of  FIG. 18 . For instance, the dimensions of the regions in  FIG. 20  may be equal to or similar to the dimensions of the similarly labeled regions in  FIG. 18 . 
     In some embodiments, using one or more masking members such as those described with respect to  FIG. 18  along with any of the processes described herein may create zones of differing average basis weights within absorbent cores, such as absorbent core  750   b.  For example, the front core region  708 ′ may have a higher average basis weight than the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′. In some embodiments, the front core region  708 ′ may have an average basis weight that is between 110% and 150% greater than the average basis weight of the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′. In general, the average basis weight of the front core region  708 ′ may range between about 200 gsm and about 800 gsm, while the average basis weight of the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′ may range between about 100 gsm and about 600 gsm. 
     Likewise, the front ear regions front ear regions  719   c ′,  719   d ′ may also have a higher average basis weight than the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′. For instance, the front ear regions front ear regions  719   c ′,  719   d ′ may have an average basis weight that is between 110% and 150% greater than the average basis weight of the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′. The average basis weight of the front ear regions front ear regions  719   c ′,  719   d ′ may also range between about 200 gsm and about 800 gsm. 
     In at least some further embodiments, the crotch region  707 ′ may additionally have a higher average basis weight than the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′. In some examples, the crotch region  707 ′ may have an average basis weight that is between 110% and 150% greater than the average basis weight of the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′, similar to the front core region  708 ′ with respect to the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′. Although, in other embodiments, the crotch region  707 ′ may have an average basis weight that is somewhat lower than the average basis weight of the front core region  708 ′. For example, the crotch region  707 ′ may have an average basis weight that is between 105% and 125% greater than the average basis weight of either the rear core region  706 ′ and/or the rear ear regions  719   a ′,  719   b ′. Accordingly, in some examples, the crotch region  707 ′ may have an average basis weight of between about 200 gsm and about 800 gsm, while in other examples, the crotch region  707 ′ may have average basis weight that ranges between about 100 gsm and about 600 gsm. 
     Accordingly, as can be seen, the average basis weight of the absorbent core  750   b  may generally increase from the rear core region  706 ′ to the front core region  708 ′. In some embodiments, the average basis weight of the absorbent core  750   b  may increase along a path between the rear core region  706 ′ and the front core region  708 ′, such as along path  751 . In some specific embodiments, the average basis weight of the absorbent core  750   b  may increase linearly along path  751 . However, in other embodiments, average basis weight of the absorbent core  750   b  may not increase in such a structured manner along path  751 . 
     Using another metric, the total amount of particulate material within the different portions of the absorbent cores  750   a - c  may also differ. For instance, using absorbent core  750   b  as an example, greater than 60% of the total particulate material content of the absorbent core  705   b  may be located within a front half of the absorbent core  750   b.  The absorbent core  750   b  may have an overall length that is equal to the sum of the front core region length  743 , the crotch region length  741 , and the rear core region length  746 . This total may equal the overall length  717  of the absorbent core region  701  described in  FIG. 18 . The front half of the absorbent core  750   b,  then, may be the portion of the absorbent core  750   b  spanning half of the sum of the front core region length  743 , the crotch region length  741 , and the rear core region length  746  that entirely overlaps the front core region  708 ′. The rear half of the absorbent core  705   b,  then, may be the portion of the absorbent core  750   b  spanning half of the sum of the front core region length  743 , the crotch region length  741 , and the rear core region length  746  that entirely overlaps the rear core region  706 ′. In further embodiments, greater than 70% of the total particulate material content of the absorbent core  750   b  may be located within the front half of the absorbent core  750   b.    
     Additionally, the exemplary absorbent core  750   b  may be broken up into thirds. For instance, the absorbent core  750   b  may have a front third portion overlapping the front core region  708 ′, a middle third portion overlapping the crotch region  707 ′, and a rear third portion overlapping the rear core portion  706 ′. Each of these portions may span a third of an overall length of the absorbent core  750   b,  e.g. a third of the sum of the front core region length  743 , the crotch region length  741 , and the rear core region length  746 , then the rear core region  706 ′. Using these thirds, the disclosed masking member and processes may cause the rear third portion to have an average basis weight that is between about 50% and about 90% of the average basis weight of the front third portion. In at least some additional embodiments, then the rear third portion may have an average basis weight that is between about 50% and about 90% of the average basis weight of the middle third portion. In some embodiments, greater than 40%, by weight, of the total particulate material content of the absorbent core  750   b  may be located within the front third portion. 
       FIG. 21  depicts a cross-section view of the absorbent core  750   c  taken along line D-D′. As can be seen in  FIG. 21 , the absorbent core  750   c  comprises both a base carrier sheet  870  and a top carrier sheet  875 . The absorbent core  750   c  further includes particulate material  889  stabilized with both a first adhesive  876  and a second adhesive  886 . The first adhesive  876  may comprise a hot-melt adhesive, such as any of those described in this disclosure. The second adhesive  886  may comprise either a hot-melt adhesive or a SAAB adhesive, such as any of those described in this disclosure. The first adhesive  876  and the second adhesive  886  may act to maintain the positioning of the particulate material  889  within the absorbent core  750   c.    
     The absorbent core  750   c  of  FIG. 21  can be seen broken up into a rear core region  806 , a crotch region  807 , and a front core region  808 , which span the absorbent core  750   c  in the machine direction  854 . Additionally, as can be seen, each of the different regions  806 ,  807 , and  808  have different average basis weights. For instance, near the rear core region  806 , the absorbent core  750   c  has a particulate material depth  810 , while the front core region  808  has a particulate material depth  812 , which is greater than the particulate material depth  810 . Additionally, the particulate material depth throughout the crotch region  807  can be seen generally increasing. In some embodiments, the increase may be generally linear. However, this is not necessarily the case in all embodiments. These differences in the particulate material depths in the rear core region  806 , the crotch region  807 , and the front core region  808  may result in the described differences in average basis weights within the different regions described previously. 
       FIG. 21  depicts one example cross-section shape of exemplary absorbent core  750   c.  For instance, although shown as a generally linear increase in particulate material depth throughout the crotch region  807 , this may not be the case in all embodiments. In other contemplated embodiments, the increase throughout the crotch region  807  may be non-linear. Additionally, although a maximum particulate material depth, e.g. particulate depth  812 , is shown at an edge of the absorbent core  750   c,  in other embodiments the maximum particulate material depth may be located still within the front core region  808 , but away from an edge of the front core region  808 . In these embodiments, the top carrier sheet  875  may have a wavy cross-sectional shape as the particulate material depth may increase throughout the crotch region  807 , may peak within the front core region  808 , and also decrease within the front core region  808  moving towards an edge of the front core region. 
     It should be understood, that the specific masking members and process steps described with respect to  FIGS. 18-21  may be used in conjunction with any of the processes described in this disclosure, or in separate, distinct processes not disclosed herein. For instance, masking members  700  may be used in conjunction with process  20 ,  200 , or any other process in order to produce absorbent cores having a gradient of basis weights extending from a rear region of the absorbent core a front region of the absorbent core. In further embodiments, the masking members and process steps may be used to produce absorbent cores with different average basis weights between different regions of the cores, such as within the front ear portions, within the central front core region, within the crotch region, within the central rear core region, and within the rear ear portions, as described with respect to  FIG. 20 . In this manner, particulate material may be directed toward portions of absorbent cores where the particulate material will be more effective in absorbing bodily fluids thereby decreasing the amount of particulate material located in less desirable areas of the cores. 
     In at least some alternative embodiments, instead of depositing alternating amounts of particulate material and adhesive, the apparatuses disclosed herein may be modified to deposit one or more matrix layers, with each matrix layer comprising a combination of particulate material and adhesive. For instance,  FIGS. 22A and 22B  depict top-down exemplary schematics of machinery that may be used with the various apparatuses described herein to form a matrix layer within an absorbent core. 
       FIG. 22A  depicts exemplary forming drum  526 . The forming surface  524  is depicted disposed on the forming drum  526  extending between the drum rims  552 . Particulate material delivery conduit  562  is also shown in  FIG. 22A .  FIG. 22A  further depicts adhesive application nozzles  510  and air blowers  511 . In some embodiments, the particulate material delivery conduit  562  and the adhesive application nozzles  510  may be disposed within an overall chamber (not shown in  FIG. 22A ), for example a particulate material delivery chamber as described herein, but this is not necessary in all embodiments. 
     As shown in  FIG. 22A , the particulate material delivery conduit  562  can generally extend for a length in a machine direction  554  that is greater than a width that the particulate material delivery conduit  562  extends in a cross-machine direction  556 . Additionally, the particulate material delivery conduit  562  may generally be disposed over a center region of the forming surface  524 . Some example lengths for the particulate material delivery conduit  562  range from between about 10 cm to about 100 cm. Some example widths for the particulate material delivery conduit  562  range from between about 15 cm to about 50 cm. 
     Disposed adjacent to the particulate material delivery conduit  562  are one or more adhesive application nozzles  510 . The adhesive application nozzles  510  may be configured to deliver adhesive into particulate material as the particulate material falls from the particulate material delivery conduit  562  toward the forming surface  524 . When particulate material is delivered from the particulate material delivery conduit  562 , and adhesive delivered from the adhesive application nozzles  510 , the particulate material and the adhesive intermix as they fall toward the forming surface  524 . As the particulate material and the adhesive are deposited at the forming surface  524 , the particulate material and the adhesive form a matrix of particulate material and adhesive, as described in more detail below. 
     In some embodiments, the adhesive application nozzles  510  may be configured to provide a generally continuous stream of adhesive, while in other embodiments one or more of the adhesive application nozzles  510  may be configured to alternatingly be turned “on” and “off” to provide discontinuous streams of adhesive through one or more of the adhesive application nozzles  510 . Although depicted as five separate adhesive application nozzles  510 , in other embodiments, additional or fewer adhesive application nozzles  510  may be used. In different embodiments, the number of adhesive application nozzles  510  may range from between about five to about twenty. 
     Air blowers  511  are optional components and, where present, may generally be disposed on either side of the particulate material delivery conduit  562 /adhesive application nozzles  510 , or on both sides as shown in  FIG. 22A . In the example of  FIG. 22A , the air blowers  511  may be disposed a distance  512  from the particulate material delivery conduit  562  and a distance  514  from the adhesive application nozzles  510 . The distance  512  may range between about 1 cm and about 10 cm. The distance  514  may range between about 3 cm and about 8 cm. 
     Where present, the air blowers  511  may deliver air jets at predetermined velocities, sufficient to urge the adhesive streams from at least some of the adhesive application nozzles  510  inward and toward the center of the substrate the forming surface  524 , either continuously or for periodic intervals. The periodic intervals may be effected by periodically switching one or more of the air blowers  511  “on” and “off,” by periodically blocking or diverting the jets of air from the air blowers  511  so that the jets of air do not manipulate the adhesive streams and/or particulate material, or by reducing the force of the jets of air to manipulate the adhesive streams and/or particulate material to a lesser extent. In this manner, the use of the air blowers  511  may allow for shaping of the adhesive and/or particulate material, particularly influencing the extent to which the adhesive and/or particulate material is deposited at the forming surface  524  in the cross-machine direction  556 . The air blowers  511  may help to comingle the particulate material and the adhesive as they are delivered from the particulate material delivery conduit  562  and the adhesive application nozzles  510 , respectively, as the particulate material and the adhesive fall toward the forming surface  524 . The air blowers  511  may have an opening diameter of about 0.5-5 mm, suitably about 1-3 mm, depending on the size of absorbent core being formed, line speed, number of air nozzles, air pressure, adhesive basis weight, and other process variables. 
       FIG. 22B  depicts another exemplary absorbent material delivery chamber  560 ′ disposed over forming drum  526 ′. The forming surface  524 ′ is depicted disposed on the forming drum  526 ′ extending between the drum rims  552 ′. In general, the embodiment shown in  FIG. 22B  may be similar to the embodiment shown in  FIG. 22A . However, in the embodiment of  FIG. 22B , the orientation of the particulate material delivery conduit  562 ′ and the adhesive application nozzles  510 ′ may be skewed with respect to the machine direction  554 ′. For example the particulate material delivery conduit  562 ′ and the adhesive application nozzles  510 ′ may be oriented at an angle  520  with respect to the machine direction  556 ′. The angle  520  may range from between one degree to ninety degrees. 
     In general, the angle  520  may be chosen in order to influence a cross-machine direction  554 ′ spread of the deposited particulate material from the particulate material delivery conduit  562 ′ and the adhesive from the adhesive application nozzles  510 ′. As can be seen in  FIG. 22B , with the particulate material delivery conduit  562 ′ and the adhesive application nozzles  510 ′ oriented at the angle  520 , the cross-machine direction  556 ′ spread of the deposited particulate material and the adhesive may be greater than the cross-machine direction  556  spread of the deposited particulate material and the adhesive in  FIG. 22A  because the particulate material delivery conduit  562 ′ and the adhesive application nozzles  510 ′ span an initially greater cross-machine direction  556 ′ distance than the distance the particulate material delivery conduit  562  and the adhesive application nozzles  510  span in the cross-machine direction  556 . 
     In general, the components described above with respect to  FIGS. 22A and 22B  may be incorporated into any of the processes described with respect to apparatuses  20 ,  200 , or  300 . The components may be used in place of either of the first particulate material delivery chamber in any of the described processes or any subsequent particulate material delivery chamber. In this manner, the matrix of particulate material and adhesive formed by use of the components of  FIGS. 22A or 22B  may be either formed on a base carrier sheet or on any prior application of particulate material or adhesive. In at least some embodiments, the disclosed apparatuses may comprise two or more instances of the components of  FIGS. 15A and/or 15B  to form absorbent cores that have two or more matrices, or a thicker region, of particulate material and adhesive disposed within an absorbent core. 
     The spread of the deposited matrix of particulate material and adhesive in the cross-machine direction  556  within formed absorbent cores may generally be less than the spread of other non-matrix applications of particulate material and adhesive of the absorbent cores. For instance, where the matrix of particulate material and adhesive is a deposited as a second application, the first application of particulate material (again, which may not be part of a matrix with adhesive) may span a majority of a cross-machine direction  556  width of the formed absorbent core. The matrix of particulate material and adhesive, however, may span in the cross-machine direction  556  less than the first application of particulate material. This may allow targeting of particulate material to areas of the absorbent core that will be most beneficial for absorption, e.g. where the particulate material in the matrix of particulate material and adhesive is only present in particular regions of the absorbent core. This may further allow for the overall particulate material content of the formed absorbent core to be less than if the matrix of particulate material and adhesive spanned the whole cross-machine direction  556  width of the absorbent core, or at least to the same extent as the first application of particulate material. 
       FIG. 23  depicts a side view of the components described in  FIGS. 22A and 22B . As can be seen in  FIG. 23 , adhesive  530  may exit adhesive application nozzles  510  and particulate material  532  may exit the particulate material delivery conduit  562  above air streams  534  created by air blowers  511   a,    511   b.  As the particulate material  532  and the adhesive  530  travel toward the forming surface  524 , the particulate material  534  and the adhesive  530  become entrained in air streams  534  and become comingled in region  535  above the forming surface  524 . This can be seen in  FIG. 23  as the adhesive  530  is intermixed with the particulate material  532  in the region  535  before being deposited at the forming surface  524  as a matrix of particulate material  532  and adhesive  530 . Generally, the matrix of particulate material  532  and adhesive  530  deposited at the forming surface  524  may span in the cross-machine direction  556  a width  531 . Again, it should be understood that air blowers  511   a,    511   b  are option components. In embodiments where air blowers  511   a,    511   b  are not present, the particulate material  532  and adhesive  530  may still intermix as they fall toward the forming surface  524 . For instance, vacuum pressure may draw the particulate material  532  and adhesive  530  toward the forming surface  524  and cause the particulate material  532  and adhesive  530  to intermix. 
     In some embodiments, the rate of revolution of the forming drum  526  in the machine direction  554 , the weight and volume of the particulate material  532  exiting the particulate material delivery conduit  562 , the weight and volume of the adhesive  530  exiting the adhesive application nozzles  510 , the strength of the air streams  534  from the air blowers  511   a,    511   b,  and other process factors may be modified to create a width  531  that may be between about 5 cm and about 15 cm. In some embodiments, the strength of the vacuum within the forming drum  526  may also influence the width  531 . For example, a stronger vacuum within the forming drum  526  may influence the particulate material  532  and the adhesive  530  as they fall toward the forming surface  524  and cause the particulate material  532  and the adhesive  530  to spread more in the cross-machine direction  556  than in comparison to a weaker vacuum within the forming drum  526 . 
     Air blowers  511   a,    511   b  may additionally include nozzles  513   a,    513   b  that direct the streams of air  534  toward the particulate material  532  and the adhesive  530 . In at least some embodiments, the nozzles  513   a,    513   b  may be angled toward the forming surface  524  at an angle  533 . The angle  533  may range between about zero degrees to about sixty degrees. 
       FIG. 24  depicts a length of formed absorbent cores  570  comprising connected, individual absorbent cores  571   a - c  that may be formed using any of the processes described herein and further including a matrix of particulate material and adhesive formed by the processes described with respect to  FIGS. 22A, 22B, and 23 . The connected, individual absorbent cores  571   a - c  may later be separated forming discrete individual absorbent cores, for example by cutting along cut lines  575 . 
     The formed absorbent cores  571   a - c  may have an overall core width  595  and may include a center region  580  having a center width  590 . The absorbent cores  571   a - c  may further include a first edge region  581  having a first edge region width  591  and a second edge region  582  having a second edge region width  592 . In some embodiments, the center width  590  may generally correspond to the cross-machine direction  556  spread of the matrix region of particulate material and adhesive of the absorbent cores  571   a - c.  In these embodiments, the center width  590  may range between about one-quarter to about three-quarters of the overall core width  595 . Accordingly, the cross-machine direction  556  spread of the matrix of particulate material and adhesive of the absorbent cores  571   a - c  may range between about one-quarter to about three-quarters of the overall core width  595 . More generally, the center region  580  may correspond to a crotch region of the absorbent core  571   a - c.  For instance, in some embodiments, the absorbent cores  571   a - c  may be shaped, for instance as described with respect to  FIGS. 10 and 11 . In these embodiments, the center width  590  of the center region  580  may correspond to the width of the crotch region of these shaped absorbent cores. This may help to ensure that additional particulate material is located at positions of the absorbent cores where the additional particulate material is able to be most effective, while also ensuring that additional particulate material is not added to locations where the particulate material is not needed or would be less effective, thus helping to keep manufacturing costs down. 
     In these embodiments, then, the first edge region width  591  and the second edge region width  592  may range between about three-eighths and about one-eighth of the overall core width  595 . In some specific examples, the overall core width  595  may be between about 3 cm and about 25 cm. In these examples, the center width  590  may range between about 0.75 cm and about 18.75 cm, or more generally between about 1 cm and about 20 cm. The first edge region width  591  and the second edge region width  592 , then, may range generally between about 1 cm and about 10 cm. 
     Another feature of the absorbent cores  571   a - c  is that since the matrix of particulate material and adhesive spans only a portion of the overall core width  595 , the different regions of the absorbent cores  571   a - c  may have different amounts of particulate material. For instance, in some embodiments, at least 25% of the total amount of particulate absorbent material in one of the absorbent cores  571   a - c  may be located within the center region  580 . In other embodiments, at least 50% of the total amount of particulate material in one of the absorbent cores  571   a - c  may be located within the center region  580 . In still further embodiments, at least 75% of the total amount of particulate material in one of the absorbent cores  571   a - c  may be located within the center region  580 . These values may translate into particulate material and adhesive basis weights of between about 100 gsm and about 1000 gsm. Accordingly, the basis weights of the particulate material and adhesive located within the first edge region width  591  and the second edge region width  592  may range between about 50 gsm and about 400 gsm. These values may span a useful range for different absorbent articles where the cores  571   a - c  may be ultimately used. 
       FIGS. 25 and 26  depict cross-sections of exemplary absorbent cores  600  and  601  that may represent a cross-section of the absorbent core  571   b  taken along line B-B′ in  FIG. 24 . In the example of  FIG. 25 , the absorbent core  600  may comprise a base carrier sheet  587 . In at least some embodiments, a first adhesive  584 , represented by the ‘x’s, may be disposed directly on the base carrier sheet  587 . Absorbent core  600  further includes a first amount of particulate material  593   a  applied directly to the first adhesive  584  (or directly to the base carrier sheet  587  in embodiments that do not include the first adhesive  584  disposed directly on the base carrier sheet  587 ) forming region  596 . 
     Although not necessary in all embodiments, absorbent core  600  may further include a second adhesive  583 , as represented by the ‘w’s. In these embodiments, the second adhesive  583  may be applied onto the first amount of particulate material  593   a  that formed region  596 . In at least some embodiments, the second adhesive  583  may comprise a spray application aqueous binder (SAAB) adhesive. In these examples, as shown in  FIG. 25 , the second adhesive  583  may penetrate into the particulate material  593   a  within region  596 . Again, it should be understood that the second adhesive  583  may be applied only in some contemplated embodiments. 
     Whether a second adhesive  583  is present or not, a matrix of particulate material and adhesive  585  may be disposed adjacent to the first amount particulate material  593   a  that forms regions  596 . The matrix of particulate material and adhesive  585  may generally comprise a second amount of particulate material  593   b  and adhesive fibers  586 . The adhesive fibers  586  may be formed, for example, by adhesive application nozzles  510  described above with respect to  FIGS. 22A, 22B , and  23 . The matrix of particulate material and adhesive  585  may be generally disposed within region  597 . 
     The matrix of particulate material and adhesive  585  forming region  596  may comprise particulate material and adhesive having a basis weight ranging between about 100 gsm to about 500 gsm. Additionally as can be seen, the matrix of particulate material and adhesive  585  may generally span throughout the center region  580 , whereas the first amount of particulate material  593   a  may span throughout the whole width of the absorbent core  600 , including throughout the first edge region  581  and the second edge region  582 . Due to this fact, the center region  580  may generally have a higher basis weight, of both particulate material and adhesive, than either of the first edge region  581  and the second edge region  582 . 
     Although not shown explicitly in  FIG. 25 , in at least some embodiments, the absorbent core  600  may additionally include a third adhesive disposed between the top carrier sheet  588  and matrix of particulate material and adhesive  585 . The third adhesive may either may applied directly to the matrix of particulate material and adhesive  585  or may be applied directly to the top carrier sheet  588 , in accordance with previously disclosed techniques. 
     Finally, a top carrier sheet  588  may be applied to the matrix of particulate material and adhesive  585  resulting in the top carrier sheet  588  being disposed directly on the matrix of particulate material and adhesive  585  or on the third adhesive. Additionally, as described previously, in some embodiments, the top carrier sheet  588  may be the bottom carrier sheet  587  folded onto the matrix of particulate material and adhesive  585  or the third adhesive to form the top carrier sheet  588 . 
       FIG. 26  depicts exemplary absorbent core  601 . Exemplary absorbent core  601  may comprise a base carrier sheet  587 ′. In at least some embodiments, a matrix of particulate material and adhesive  585 ′ may then be disposed directly on the base carrier sheet  587 ′. Alternatively in other embodiments, a first adhesive  584 ′ may be disposed directly on the base carrier sheet  587 ′ and the matrix layer  585 ′ may then be disposed directly on the first adhesive layer  584 ′. In either case, as can be seen in  FIG. 26 , the matrix of particulate material and adhesive  585 ′ may only span across a portion of the absorbent core  601 . For instance, the matrix of particulate material and adhesive  585 ′ may only span across the center portion  580  of the absorbent core  601 . The matrix of particulate material and adhesive  585 ′ may comprise both particulate material  593   b ′ and adhesive fibers  586 ′. As can be seen, particulate material  593   b ′ and the adhesive fibers  586 ′ are intermixed to form the matrix of particulate material and adhesive  585 ′. Additionally, the matrix of particulate material and adhesive  585 ′ may comprise particulate material and adhesive having a basis weight between about 100 gsm to about 500 gsm. 
     The absorbent core  601  may further comprise other particulate material, e.g. particulate material  593   a ′, that is not part of a matrix of particulate material and adhesive fibers. The other particulate material  593   a ′ may have been applied to the absorbent core  601  after the matrix of particulate material and adhesive  585 ′ had been applied to the absorbent core. The other particulate material  593   a ′ may further be applied to the absorbent core  601  throughout the entire width of the absorbent core  601 . Accordingly, as can be seen in  FIG. 26 , the other particulate material  593   a ′ may span throughout all of regions  580 - 582 , whereas the matrix of particulate material and adhesive  585 ′ may only span throughout the center region  580 . This may then result in the center portion  580  of the absorbent core  601  having a higher basis weight, both in terms of particulate material  592   a ′ and  593   b ′ and adhesive, than either of the first edge region  581  and the second edge region  582 . 
     In some embodiments, a second adhesive  583 ′ may be disposed on the other particulate material  593   a ′. For instance, the second adhesive  583 ′ may be applied directly to the other particulate material  593   a ′. As shown in  FIG. 26 , the second adhesive  583 ′ may be a spray application aqueous binder (SAAB) adhesive, and the second adhesive  583 ′ may penetrate throughout the other particulate material  593   a ′. Although not shown in  FIG. 26 , in some instances, the second adhesive  583 ′ may further penetrate the matrix of particulate material and adhesive  585 ′. However, in other embodiments, the second adhesive  583 ′ may not be a SAAB adhesive. For example, the second adhesive  583 ′ may be a hot-melt or other suitable adhesive. In these instances, the second adhesive  583 ′ may be applied directly to the other particulate material  593   a ′ and may not appreciably penetrate the other particulate material  593   a ′, or the second adhesive  583 ′ may be applied to the top carrier sheet  588 ′ before the top carrier sheet  588 ′ is applied to the other particulate material  593   a ′. In still further embodiments, the second adhesive  583 ′ may be a SAAB adhesive, and the absorbent core  601  may additionally comprise a third adhesive that is a hot-melt adhesive disposed between the other particulate material  593   a ′ and the top carrier sheet  588 ′. Accordingly, whether applied directly to the other particulate material  593   a ′ or the top carrier sheet  588 ′, the second adhesive  583 ′ may be disposed generally between the other particulate material  593   a ′ and the top carrier sheet  588 ′. 
     Finally, a top carrier sheet  588 ′ is shown disposed adjacent to the other particulate material  593   a ′. Again, depending on the specific embodiment, the top carrier sheet  588 ′ may be disposed directly on the other particulate material  593   a ′ or there may be an adhesive disposed between the other particulate material  593   a ′ and the top carrier sheet  588 ′. Additionally, as described previously, in some embodiments, the top carrier sheet  588 ′ may be the bottom carrier sheet  587 ′ folded onto the first particulate absorbent material layer  593 ′ or the third adhesive layer  586 ′ to form the top carrier sheet  588 ′. 
     The pulpless absorbent cores the present disclosure may be used in many different absorbent articles. For example, pulpless absorbent cores the present disclosure may be used in diapers and/or training pants in order to help absorb urine and other liquid discharge from babies and toddlers. The pulpless absorbent cores the present disclosure may additionally, or alternatively, be used in incontinence products, disposable underwear, and/or medical garments to help absorb liquid discharge from people who may not be able to control their ability to urinate or defecate. Even further, the pulpless absorbent cores the present disclosure may additionally, or alternatively, be used in feminine care articles to help absorb vaginal discharges. These are just some example absorbent articles in which the pulpless absorbent cores the present disclosure may be used. In general, the pulpless absorbent cores the present disclosure may be used in any suitable absorbent article application. 
     As various changes could be made in the above without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.