Patent Publication Number: US-2020281155-A1

Title: Absorbent pad

Description:
TECHNICAL FIELD 
     The present disclosure is generally related to absorbent pads and more specifically related to an absorbent pad for collecting pet urine. 
     BACKGROUND INFORMATION 
     Pet owners may find it desirable to housetrain a new pet (e.g., a dog). The housetraining process may involve the pet owner teaching the pet to use a consistent location within the home to urinate. An absorbent pad may be placed at the location where the pet is taught to urinate such that urine is absorbed by the pad. As such, the urine may be more easily disposed of without harm to surfaces (e.g., a floor) within the home. 
     SUMMARY 
     An example absorbent pad may include a liquid permeable layer, a liquid impermeable layer, and a liquid absorbent layer disposed between the liquid permeable layer and the liquid impermeable layer. The liquid absorbent layer may include a first absorption region and a second absorption region. The second absorption region may extend around the first absorption region and may be configured to absorb more liquid per unit area than the first absorption region. 
     Another example absorbent pad may include a liquid permeable layer, a liquid impermeable layer, an attractant layer configured to attract an animal, and a liquid absorbent layer disposed between the liquid permeable layer and the liquid impermeable layer. The liquid absorbent layer may define a first absorption region and a second absorption region. The second absorption region may extend around the first absorption region and the second absorption region may be configured to absorb more liquid per unit area than the first absorption region. The liquid absorbent layer may include a pulp sublayer, a tissue sublayer, and a superabsorbent pulp sublayer. The pulp sublayer may be disposed between the tissue sublayer and the superabsorbent polymer sublayer. A portion of the superabsorbent polymer sublayer corresponding to the first absorption region may include a first quantity of superabsorbent polymer and a portion of the superabsorbent polymer sublayer corresponding to the second absorption region may include a second quantity of superabsorbent polymer. The second quantity of superabsorbent polymer may measure greater than the first quantity of superabsorbent polymer. 
     An example method of using an absorbent pad may include placing the absorbent pad on a floor. The absorbent pad may include a liquid permeable layer, a liquid impermeable layer, and a liquid absorbent layer disposed between the liquid permeable layer and the liquid impermeable layer. The liquid absorbent layer may include a first absorption region and a second absorption region. The second absorption region may extend around the first absorption region and may be configured to absorb more liquid per unit area than the first absorption region. When the liquid is at least partially absorbed by the second absorption region, the second absorption region defines a raised region such that the first absorption region is recessed relative to the second absorption region. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages will be better understood by reading the following detailed description, taken together with the drawings, wherein: 
         FIG. 1  is a schematic view of an example of an absorbent pad, consistent with embodiments of the present disclosure. 
         FIG. 2  is a schematic cross-sectional view of an example of an absorbent layer capable of being used with the absorbent pad of  FIG. 1 , consistent with embodiments of the present disclosure. 
         FIG. 3  is a schematic view of an example of an absorbent pad, consistent with embodiments of the present disclosure. 
         FIG. 4  is a schematic cross-sectional view of the absorbent pad of  FIG. 3  after a liquid has been absorbed therein taken along the line IV-IV, consistent with embodiments of the present disclosure. 
         FIG. 5  is a schematic cross-sectional view of the absorbent pad of  FIG. 3  taken at a recessed region, consistent with embodiments of the present disclosure. 
         FIG. 6  is a schematic cross-sectional view of the absorbent pad of  FIG. 3  taken at a raised region, consistent with embodiments of the present disclosure. 
         FIG. 7  is a schematic cross-sectional view of the absorbent pad of  FIG. 3  taken at a peripheral region, consistent with embodiments of the present disclosure. 
         FIG. 8A  is a magnified view of a portion of the absorbent pad of  FIG. 3 , consistent with embodiments of the present disclosure. 
         FIG. 8B  is a magnified view of a portion of an absorbent pad, such as the absorbent pad of  FIG. 3 , having cells defined therein, consistent with embodiments of the present disclosure. 
         FIG. 9  is a schematic view of an example of an absorbent pad, consistent with embodiments of the present disclosure. 
         FIG. 10  is a schematic view of an example of an absorbent pad, consistent with embodiments of the present disclosure. 
         FIG. 11  shows a flow chart of an example method of using an absorbent pad, such as the absorbent pad of  FIG. 1 , consistent with embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present disclosure is generally related to an absorbent pad for use with household pets. The absorbent pad preferably includes at least three layers. A first layer is configured to engage a surface, such as a floor. The first layer is liquid resistant such that liquid does not permeate through the first layer. A second layer is disposed on the first layer and is configured to be liquid absorbent. A third layer is disposed on the second layer such that the second layer is disposed between the first and third layers. The third layer is configured to be liquid permeable such that at least a portion of liquid incident thereon passes through the third layer. As such, liquid that passes through the third layer is at least partially absorbed by the second layer and any liquid that is not absorbed by the second layer is prevented from passing through the first layer and onto a surface that the first layer engages (e.g., a floor). 
     In some instances, the absorbent pad can define a first absorption region and a second absorption region. The second absorption region extends around the first absorption region. The absorption properties of the first absorption region may be configured to be different from those of the second absorption region. For example, the second absorption region may be configured to absorb a greater quantity of liquid per unit area than the first absorption region. Such a configuration may reduce or otherwise mitigate an amount of liquid that escapes the absorbent pad. 
       FIG. 1  shows a schematic example of a preferred absorbent pad  100  having a first layer  102 , a second layer  104 , and a third layer  106 , the second layer  104  being disposed between the first layer  102  and the third layer  106 . The absorbent pad  100  is configured to be disposed on a surface (e.g., a floor) such that the first layer  102  engages the surface. The first layer  102  is configured to be impermeable to liquids such that liquid incident thereon does not pass therethrough. As such, when an animal (e.g., a dog) positions itself on the absorbent pad  100  to urinate, urine will not pass through the absorbent pad  100  and on to, for example, a floor on which the absorbent pad  100  is disposed. 
     The second layer  104  is configured to be absorbent such that at least a portion of a liquid incident thereon is absorbed by the second layer  104 . In some instances, the second layer  104  can have two or more absorption regions. For example, the second layer  104  can include a first absorption region  108  and a second absorption region  110 . As shown, the second absorption region  110  can extend around the first absorption region  108 . The second absorption region  110  can be configured to absorb more liquid per unit area than the first absorption region  108 . As such, excess liquid may be prevented from running off the absorbent pad  100  (e.g., if a pet urinates at an off-center location) by being absorbed within the second absorption region  110 . 
     The third layer  106  extends over at least a portion of the second layer  104  and is configured to be liquid permeable such that at least a portion of the liquid incident thereon passes therethrough. Therefore, the second layer  104  can generally be described as being disposed between the first and third layers  102  and  106 . As such, when a pet urinates on the third layer  106 , a substantial portion of the urine passes through the third layer  106  such that at least a portion of the urine can be absorbed by the second layer  104 . In some instances, the third layer  106  can couple the second layer  104  to the first layer  102 . 
     The absorbent pad  100  can have any shape. For example, the absorbent pad  100  can be square-shaped, rectangle-shaped, circular-shaped, pentagonal-shaped, octagonal-shaped, and/or any other shape. 
       FIG. 2  shows a schematic cross-sectional view of an absorbent layer  200 , which may be an example of the second layer  104  of  FIG. 1 . As shown, the absorbent layer  200  includes a first sublayer  202 , a second sublayer  204 , and a third sublayer  206 , the second sublayer  204  being disposed between the first and third sublayers  202  and  206 . The third sublayer  206  can be configured to engage, for example, the first layer  102  of  FIG. 1  and the first sublayer  202  can be configured to engage, for example, the third layer  106  of  FIG. 1 . 
     The first sublayer  202  can be configured to be more absorbent than the second sublayer  204  and the second sublayer  204  can be configured to be more absorbent than the third sublayer  206 . As such, in some instances, the sublayers  202 ,  204 , and  206  can generally be described as increasing in absorbency in a direction away from the first layer  102 . Therefore, in some instances, a majority of a liquid incident on the absorbent layer  200  can be absorbed by the first sublayer  202 . 
     As shown, the first sublayer  202  can include a first absorption region  208  and a second absorption region  210 . The second absorption region  210  can be configured to absorb more liquid per unit area than the first absorption region  208 . In some instances, the second absorption region  210  can extend around the first absorption region  208 , enclosing the first absorption region  208 . 
     The first sublayer  202  can include a superabsorbent polymer. The superabsorbent polymer can be unevenly distributed across the first sublayer  202 . For example, the second absorption region  210  can include more superabsorbent polymer by mass than the first absorption region  208 . As such, the second absorption region  210  can absorb more liquid per unit area than the first absorption region  208 . The second sublayer  204  can include a pulp (e.g., a paper pulp) and the third sublayer  206  can include tissue paper. The second and third sublayers  204  and  206  can also have first and second absorption regions that generally correspond to the first and second absorption regions  208  and  210  of the first sublayer  202 . 
       FIG. 3  shows a schematic example of an absorbent pad  300 , which may be an example of the absorbent pad  100  of  FIG. 1 . As shown, the absorbent pad  300  includes a recessed region  302 , a raised region  304 , and a peripheral region  306 . In some instances, a step region  303  can extend around the raised region  304  such that the step region  303  is disposed between the peripheral region  306  and the raised region  304 . The step region  303  can have a configuration (e.g., layers or sublayers) similar to that of, for example, the recessed region  302 , the raised region  304 , and/or the peripheral region  306 . For example, the step region  303  may be at least partially defined by at least a portion of one or more of the recessed region  302 , the raised region  304 , and/or the peripheral region  306 . 
     The recessed region  302  and the step region  303  are configured to be recessed relative to the raised region  304  in response to a liquid being at least partially absorbed by the absorbent pad  300  (e.g., the recessed region  302 , the raised region  304 , and/or the step region  303 ). In other words, the raised region  304  is configured to expand (e.g., raise) in response to liquid being absorbed therein. As such, when a liquid is absorbed by the recessed region  302 , the step region  303 , and the raised region  304 , the recessed region  302  and the step region  303  can be configured to be recessed relative to the raised region  304 . When in a dry state, the raised region  304 , the recessed region  302 , and the step region  303  may be substantially co-planar when the absorbent pad  300  is disposed on a surface for use by an animal (e.g., the raised region  304 , the recessed region  302 , and the step region  303  may not be readily identifiable by a user of the absorbent pad  300  prior to at least partially absorbing a liquid). In some instances, at least a portion of the absorbent pad  300  can be embossed to show one or more designs. The embossed designs may be configured to encourage a flow direction of a liquid and/or to visually identify a location of, for example, the recessed region  302  and/or the raised region  304 . In some instances, the recessed region  302  and the step region  303  are also configured to expand in response to a liquid being absorbed therein (e.g., at an expansion rate that is slower than that of the raised region  304 ). 
     The raised region  304  extends around the recessed region  302  and the peripheral region  306  extends around the raised region  304 . In some instances, the raised region  304  may enclose (e.g., extend continuously around) the recessed region  302 . The raised region  304  and the recessed region  302  can be configured such that excess liquid (e.g., unabsorbed liquid) collects within the recessed region  302  (e.g., after the raised region  304  has started expanding). 
     A peripheral region length  308  (e.g., which may extend between opposing sides of the peripheral region  306 ) may measure, for example, in a range of 300 millimeters (mm) to 1300 mm and a peripheral region width  310  (e.g., which may extend between opposing sides of the peripheral region  306 ) may measure, for example, in a range of 300 mm to 1300 mm. By way of further example, the peripheral region length  308  may measure in a range of 500 mm to 900 mm and the peripheral region width  310  may measure in a range of 500 mm to 900 mm. By way of still further example, the peripheral region length  308  may measure 580 mm and the peripheral region width  310  may measure 560 mm. 
     A raised region length  312  (e.g., which may extend between opposing sides of the raised region  304  or opposing sides of the step region  303 ) may measure, for example, in a range of 200 mm to 1100 mm and a raised region width  314  (e.g., which may extend between opposing sides of the raised region  304  or opposing sides of the step region  303 ) may measure, for example, in a range of 200 mm to 1100 mm. By way of further example, the raised region length  312  may measure in a range of 400 mm to 700 mm and the raised region width  314  may measure in a range of 400 mm to 700 mm. By way of still further example, the raised region length  312  may measure 520 mm and the raised region width  314  may measure 510 mm. 
     A recessed region length  316  (e.g., which may extend between opposing sides of the recessed region  302 ) may measure, for example, in a range of 200 mm to 600 mm and a recessed region width  318  (e.g., which may extend between opposing sides of the recessed region  302 ) may measure, for example, in a range of 200 mm to 600 mm. By way of further example, the recessed region length  316  may measure in a range of 300 mm to 500 mm and the recessed region width  318  may measure in a range of 300 mm to 500 mm. By way of still further example, the recessed region length  316  may measure in a range of 425 mm to 475 mm and the recessed region width  318  may measure in a range of 425 mm to 475 mm. By way of still further example, the recessed region length  316  may measure 450 mm and the recessed region width  318  may measure 440 mm. 
     A raised region thickness  320  (e.g., which may extend between an outer side and an inner side of the raised region  304  or an outer side of the step region  303  and an inner side of the raised region  304 ) may measure, for example, in a range of 5 mm to 100 mm. By way of further example, the raised region thickness  320  may measure in a range of 25 mm to 80 mm. By way of still further example, the raised region thickness  320  may measure 35 mm. A step region thickness  322  (e.g., which may extend between an outer side and an inner side of the step region  303 ) may measure, for example, in a range of 2.5 mm to 7.5 mm. By way of further example, the step region thickness  322  may measure 5 mm. 
       FIG. 4  is a schematic cross-sectional view of the absorbent pad  300  after a liquid has been absorbed by the absorbent pad  300  taken along the line IV-IV of  FIG. 3 . A raised region height  400 , as measured from an upper surface of the peripheral region  306  (or, instances including the step region  303 , from an upper surface of the step region  303 ) to an upper surface of the raised region  304  may measure in a range of 0.5 mm to 25 mm, when a liquid is absorbed therein. By way of further example, the raised region height  400  may measure in a range of 1 mm to 13 mm, when a liquid is absorbed therein. By way of still further example, the raised region height  400  may measure in a range of 2 mm to 5 mm, when a liquid is absorbed therein. Prior to absorbing a liquid, the raised region height  400  may measure, for example, in a range of 0.25 mm to 1 mm. 
     The recessed region  302  may have a recessed region height  402  that measures, for example, in a range of 0.25 mm to 10 mm, when a liquid is absorbed therein. By way of further example, the recessed region height  402  may measure in a range of 0.5 mm to 7 mm, when a liquid is absorbed therein. By way of still further example, the recessed region height  402  may measure in a range of 0.5 mm to 6 mm, when a liquid is absorbed therein. In some instances, the recessed region height  402  may measure substantially the same prior to and after absorption of a liquid. Prior to absorbing a liquid, the recessed region height  402  may measure, for example, in a range of 0.25 mm to 1 mm. 
     The step region  303  may have a step region height  404  that measures, for example, in a range of 0.25 mm to 10 mm, when a liquid is absorbed therein. By way of further example, the step region height  404  may measure in a range of 0.5 mm to 7 mm, when a liquid is absorbed therein. By way of still further example, the step region height  404  may measure in a range of 0.5 mm to 6 mm, when a liquid is absorbed therein. In some instances, the step region height  404  may measure substantially the same prior to and after absorption of a liquid. Prior to absorbing a liquid, the step region height  404  may measure, for example, in a range of 0.25 mm to 1 mm 
       FIG. 5  shows a schematic cross-sectional view of an example of the recessed region  302 . As shown, the recessed region  302  can include a liquid impermeable layer  502 , an absorbent layer  504 , an attractant layer  506 , and a liquid permeable layer  508 . As shown, the absorbent layer  504  is disposed between the liquid impermeable layer  502  and the attractant layer  506 . As also shown, the attractant layer  506  is disposed between the absorbent layer  504  and the liquid permeable layer  508 . As such, the attractant layer  506  can be liquid permeable. The liquid impermeable layer  502  may include a polymer (e.g., a polyethylene film), a bioplastic, a recycled plastic, and/or any other suitable material. 
     The absorbent layer  504  can include a plurality of sublayers. As shown, the absorbent layer  504  includes a superabsorbent polymer sublayer  510 , a pulp sublayer  512  (e.g., paper pulp sublayer), and a tissue sublayer  514  (e.g., a tissue paper sublayer). The pulp sublayer  512  can be disposed between the superabsorbent polymer sublayer  510  and the tissue sublayer  514 . The superabsorbent polymer sublayer  510  can include a superabsorbent polymer having, for example, a retention absorbency in a range of 30 g/g to 45 g/g, an absorption capacity in a range of 55 g/g to 65 g/g (as measured in a 0.9% NaCl aqueous solution), an absorptive rate (e.g., a quantity of time to absorb 50, 100, or 150 milliliters of liquid such as a 0.9% NaCl aqueous solution) in a range of 15 seconds to 40 seconds, a moisture content in a range of 4% to 9%, a measure of residual acrylic acid monomers in a range of 15 parts-per-million (ppm) to 25 ppm, and a bulk density in a range of 0.6 g/ml to 0.85 g/ml. By way of further example, the superabsorbent polymer sublayer  510  can include a superabsorbent polymer having a retention absorbency of 41 g/g, an absorption capacity of 60 g/g (as measured in a 0.9% NaCl aqueous solution), an absorptive rate of 29 seconds, a moisture content of 7.4%, a measure of residual acrylic acid monomers of 22 ppm, and a bulk density of 0.74 g/ml. By way of still further example, the superabsorbent polymer sublayer  510  can include a superabsorbent polymer having a retention absorbency of 40 g/g, an absorption capacity of 60 g/g (as measured in a 0.9% NaCl aqueous solution), an absorptive rate of 30 seconds, a moisture content of 7.2%, a measure of residual acrylic acid monomers of 18 ppm, and a bulk density of 0.74 g/ml. Particle sizes of the superabsorbent polymer forming the superabsorbent polymer sublayer  510  may measure less than 850 microns (μm). For example, between 80% and 90% of the particles may have a particle size measuring in a range of 180 μm to 500 μm. 
     The attractant layer  506  may include one or more attractants to encourage a pet to approach the absorbent pad  300  when there is a need to urinate. For example, the attractant may include one or more pheromones configured to encourage the pet to urinate on the absorbent pad  300 . 
       FIG. 6  shows a schematic cross-sectional view of an example of the raised region  304 . As shown, the raised region  304  can include a liquid impermeable layer  602 , an absorbent layer  604 , an attractant layer  606 , and a liquid permeable layer  608 . The absorbent layer  604  can be disposed between the liquid impermeable layer  602  and the attractant layer  606 . As also shown, the attractant layer  606  is disposed between the absorbent layer  604  and the liquid permeable layer  608 . As such, the attractant layer  606  can be liquid permeable. The liquid impermeable layer  602  may include a polymer (e.g., a polyethylene film), a bioplastic, a recycled plastic, and/or any other suitable material. 
     The absorbent layer  604  can include a plurality of sublayers. As shown, the absorbent layer  604  includes a superabsorbent polymer sublayer  610 , a pulp sublayer  612  (e.g., paper pulp sublayer), and a tissue sublayer  614  (e.g., a tissue paper sublayer). The pulp sublayer  612  can be disposed between the superabsorbent polymer sublayer  610  and the tissue sublayer  614 . The superabsorbent polymer sublayer  610  can include a superabsorbent polymer having, for example, a retention absorbency in a range of 30 g/g to 45 g/g, an absorption capacity in a range of 55 g/g to 65 g/g (as measured in a 0.9% NaCl aqueous solution), an absorptive rate (e.g., a quantity of time to absorb 50, 100, or 150 milliliters of liquid such as a 0.9% NaCl aqueous solution) in a range of 15 seconds to 40 seconds, a moisture content in a range of 4% to 9%, a measure of residual acrylic acid monomers in a range of 15 parts-per-million (ppm) to 25 ppm, and a bulk density in a range of 0.60 g/ml to 0.85 g/ml. By way of further example, the superabsorbent polymer sublayer  610  can include a superabsorbent polymer having a retention absorbency of 41 g/g, an absorption capacity of 60 g/g (as measured in a 0.9% NaCl aqueous solution), an absorptive rate of 29 seconds, a moisture content of 7.4%, a measure of residual acrylic acid monomers of 22 ppm, and a bulk density of 0.74 g/ml. By way of still further example, the superabsorbent polymer sublayer  610  can include a superabsorbent polymer having a retention absorbency of 40 g/g, an absorption capacity of 60 g/g (as measured in a 0.9% NaCl aqueous solution), an absorptive rate of 30 seconds, a moisture content of 7.2%, a measure of residual acrylic acid monomers of 18 ppm, and a bulk density of 0.74 g/ml. Particle sizes of the superabsorbent polymer forming the superabsorbent polymer sublayer  610  may measure less than 850 microns (μm). For example, between 80% and 90% of the particles may have a particle size measuring in a range of 180 μm to 500 μm. 
     The superabsorbent polymer sublayer  610  of the raised region  304  can include more superabsorbent polymer, by mass, than the superabsorbent polymer sublayer  510  of the recessed region  302 . The quantity of superabsorbent polymer in each superabsorbent polymer sublayer  510  and  610  may be evenly or unevenly distributed therein. For example, each side of the raised region  304  that extends around the recessed region  302  can include an equal quantity of superabsorbent polymer. In some instances, opposing sides of the raised region  304  can include equal quantities of superabsorbent polymer and adjacent sides of the raised region  304  can include different quantities of superabsorbent polymer. The superabsorbent polymer within each side of the raised region  304  may be evenly or unevenly distributed therein. 
     For example, the superabsorbent polymer sublayer  610  may include a quantity of superabsorbent polymer measuring in a range of 1 gram (g) to 8 g and the superabsorbent polymer sublayer  510  may include a quantity of superabsorbent polymer measuring in a range of 0.25 g to 2 g. By way of further example, the superabsorbent polymer sublayer  610  may include a quantity of superabsorbent polymer measuring 3 g and the superabsorbent polymer sublayer  510  may include a quantity of superabsorbent polymer measuring 1 g. In this example, the absorbent pad  300  may be capable of absorbing 800 milliliters (mL) to 1100 mL of liquid. By way of still further example, the superabsorbent polymer sublayer  610  corresponding to each side of the raised region  304  can include 0.75 g. In this instance, when the raised region  304  is square shaped (as shown in  FIG. 3 ), the total superabsorbent polymer within the superabsorbent polymer sublayer  610  measures 3 g. The distribution of the superabsorbent polymer within each side of the raised region  304  may be even or uneven. 
     The attractant layer  606  may include one or more attractants to encourage a pet to approach the absorbent pad  300  when there is a need to urinate. For example, the attractant may include one or more pheromones configured to encourage the pet to urinate on the absorbent pad  300 . 
       FIG. 7  shows a schematic cross-sectional view of an example of the peripheral region  306 . As shown, the peripheral region  306  may include a liquid impermeable layer  702 . In some instances, an absorbent layer  704  may extend over at least a portion of the liquid impermeable layer  702 . The liquid impermeable layer  702  may include a polymer (e.g., a polyethylene film), a bioplastic, a recycled plastic, and/or any other suitable material. The absorbent layer  704  may include at least a tissue sublayer  706 . Additionally, or alternatively, the absorbent layer  704  may include, for example, a superabsorbent polymer sublayer and/or a pulp sublayer. 
     The liquid impermeable layers  502 ,  602 , and  702  may be formed from a substantially continuous liquid impermeable film that extends through the peripheral region  306 , the raised region  304 , and the recessed region  302 . The liquid impermeable film may include a polymer (e.g., a polyethylene film), a bioplastic, a recycled plastic, and/or any other suitable material. The tissue sublayers  514 ,  614 , and  706  may be formed of a substantially continuous tissue that extends through at least a portion of the peripheral region  306 , the raised region  304 , and the recessed region  302 . The tissue may be, for example, a tissue paper. 
     The pulp sublayers  512  and  612  can extend substantially continuously within the raised region  304  and the recessed region  302 . For example, the pulp sublayers  512  and  612  can be formed of a substantially continuous layer of pulp fibers that extends through both the raised region  304  and the recessed region  302 . In some instances, the pulp sublayers  512  and  612  can include loose pulp powder that is distributed such that the pulp sublayers  512  and  612  are formed, at least partially, therefrom. 
     The superabsorbent polymer sublayer  510  may be a substantially continuous layer of loose superabsorbent polymer powder within the recessed region  302 . The superabsorbent polymer sublayer  610  may be a substantially continuous layer of loose superabsorbent polymer powder within the raised region  304 . In some instances, the loose superabsorbent polymer powder forming the superabsorbent polymer sublayer  610  may be substantially prevented from migrating (e.g., shifting) into the loose superabsorbent polymer powder forming the superabsorbent polymer sublayer  510 . Similarly, when the pulp sublayers  512  and  612  are formed of a loose pulp powder, the loose pulp powder forming the pulp sublayer  512  may be substantially prevented from migrating (e.g., shifting) into the loose pulp powder forming the pulp sublayer  612 . 
     The liquid permeable layers  508  and  608  and the attractant layers  506  and  606  may be substantially continuous layers that extend through the raised region  304  and the recessed region  302 . In some instances, the liquid permeable layers  508  and  608  and/or the attractant layers  506  and  606  can extend over the raised region  304  and the recessed region  302  and be configured to retain any loose powders (e.g., loose superabsorbent polymer powder and/or loose pulp powder) within respective ones of the recessed and raised regions  302  and  304 . Sealing regions  800  and  802  (see  FIG. 8A , showing a magnified view of a portion of the absorbent pad  300 ) may, in some instances, be formed along opposing sides of the raised region  304  such that loose powders (e.g., loose superabsorbent polymer powder and/or loose pulp powder) are substantially prevented from migrating between the recessed and raised regions  302  and  304 . As shown, the sealing region  800  can generally correspond to the step region  303 . A sealing region width  804  and  806  of each sealing region  800  and  802  may measure, for example, in a range of 2.5 mm to 7.5 mm. By way of further example, the sealing region widths  804  and  806  may measure 5 mm. 
     The sealing regions  800  and  802  can be configured to couple one or more of the liquid permeable layers  508  and/or  608  and/or one or more of the attractant layers  506  and/or  606  to one or more of the liquid impermeable layers  502 ,  602 , and/or  702 , one or more of the tissue sublayers  514 ,  614 , and/or  706 , and/or one or more of the pulp sublayers  512  and/or  612  (e.g., a portion of the pulp sublayers  512  and/or  612  not formed of a pulp powder). For example, the sealing regions  800  and  802  can be configured to be adhesively bonded and/or form a heat seal or pressure seal (e.g. utilizing rollers) that couples one or more of the liquid permeable layers  508  and/or  608  and/or one or more of the attractant layers  506  and/or  606  to one or more of the liquid impermeable layers  502 ,  602 , and/or  702 , one or more of the tissue sublayers  514 ,  614 , and/or  706 , and/or one or more of the pulp sublayers  512  and/or  612  (e.g., a portion of the pulp sublayers  512  and/or  612  not formed of a pulp powder). 
     In some instances, the recessed region  302  and raised region  304  can include a plurality of cells  808  formed therein (see  FIG. 8B  showing a magnified example of a portion of an absorbent pad having cells formed therein). Each of the plurality of cells  808  and  810  can be configured to retain a predetermined quantity of superabsorbent polymer powder and/or pulp powder therein. 
     For example, cells  810  defining the raised region  304  can include more superabsorbent polymer by mass than cells  808  forming the recessed region  302 . The cells  808  and  810  can generally be described as preventing powders from migrating between the recessed region  302  and the raised region  304 . For example, the borders of each of the cells  808  and  810  can be sealed using an adhesive and/or heat sealing as discussed herein in relation to the sealing regions  800  and  802 . 
       FIG. 9  shows a schematic example of an absorbent pad  900 , which may be an example of the absorbent pad  100  of  FIG. 1 . As shown, the absorbent pad  900  includes a recessed region  902 , a raised region  904 , and a peripheral region  906 . The raised region  904  extends around the recessed region  902  and the peripheral region  906  extends around the raised region  904 . The raised region  904  can be configured to expand (e.g., raise) in response to liquid being absorbed therein such that the recessed region  902  is recessed relative to the raised region  904 . The raised region  904  and the recessed region  902  can be configured such that liquid (e.g., unabsorbed liquid) collects within the recessed region  902 . As such, the recessed region  902  and the raised region  904  can be configured to absorb at least a portion of the liquid deposited thereon. 
     In some instances, a step region  903  can extend around the raised region  904  such that the step region  903  is disposed between the peripheral region  906  and the raised region  904 . The step region  903  can have a configuration (e.g., layers or sublayers) similar to that of the recessed region  902 , the raised region  904 , and/or the peripheral region  906 . For example, the step region  903  may be at least partially defined by at least a portion of one or more of the recessed region  902 , the raised region  904 , and/or the peripheral region  906 . 
     In some instances, a first set of opposing sides  908  of the raised region  904  can include a first quantity of superabsorbent polymer and a second set of opposing sides  910  of the raised region  904  can include a second quantity of superabsorbent polymer. For example, the first set of opposing sides  908  may each include 1 g of superabsorbent polymer and the second set of opposing sides  910  may include 1.5 g of superabsorbent polymer. In these instances, the recessed region  902  may not include superabsorbent polymer. 
       FIG. 10  shows a schematic example of an absorbent pad  1000 , which may be an example of the absorbent pad  100  of  FIG. 1 . As shown, the absorbent pad  1000  includes a recessed region  1002 , a raised region  1004 , and a peripheral region  1006 . In some instances, a step region  1008  can extend around the raised region  1004  such that the step region  1008  is disposed between the peripheral region  1006  and the raised region  1004 . The step region  1008  can have a configuration (e.g., layers or sublayers) similar to that of the recessed region  1002 , the raised region  1004 , and/or the peripheral region  1006 . For example, the step region  1008  may be at least partially defined by at least a portion of one or more of the recessed region  1002 , the raised region  1004 , and/or the peripheral region  1006 . 
     The recessed region  1002  and the step region  1008  are configured to be recessed relative to the raised region  1004  in response to a liquid being at least partially absorbed by the absorbent pad  1000  (e.g., the recessed region  1002 , the raised region  1004 , and/or the step region  1008 ). In other words, the raised region  1004  is configured to expand (e.g., raise) in response to liquid being absorbed therein. As such, when a liquid is absorbed by the recessed region  1002 , the step region  1008 , and the raised region  1004 , the recessed region  1002  and the step region  1008  can be configured to be recessed relative to the raised region  1004 . 
     As shown, the raised region  1004  can include one or more ridges  1010  defined therein. The one or more ridges  1010  can extend from the recessed region  1002  prior to a liquid being absorbed by at least a portion of the absorbent pad  1000 . As such, the one or more ridges  1010  may help retain at least a portion of a liquid incident on the absorbent pad  1000  within the recessed region  1002  and/or raised region  1004  prior to the raised region  1004  expanding in response to a liquid absorbed therein. The one or more ridges  1010  can be configured to expand with the raised region  1004  in response to the raised region  1004  absorbing a liquid incident on the absorbent pad  1000 . As such, the one or more ridges  1010  may extend from the raised region  1004  after the raised region  1004  absorbs a liquid. A height of the one or more ridges  1010  prior to the absorbent pad  1000  absorbing liquid may measure in a range of 0.1 mm to 10 mm. 
     In some instances, the raised region  1004  can include two or more ridges  1010 . For example, the ridges  1010  can be spaced apart from each other such that a channel is defined between adjacent ridges  1010 . For example, a separation distance between adjacent ridges may measure in a range of 3 mm to 15 mm. The channel can be configured to retain liquid prior to being absorbed by, for example, the raised region  1004 . 
       FIG. 11  shows an example of a preferred method  1100  of using an absorbent pad, such as the absorbent pad  100  of  FIG. 1 . As shown, the method  1100  includes a step  1102 . The step  1102  can include placing the absorbent pad on a surface such as a floor. The absorbent pad can include a liquid permeable layer, a liquid impermeable layer, and a liquid absorbent layer disposed between the liquid permeable layer and the liquid impermeable layer. The liquid absorbent layer may include a first absorption region and a second absorption region. The second absorption region may extend around the first absorption region and may be configured to absorb more liquid per unit area than the first absorption region. 
     The method  1100  may include a step  1104 . The step  1104  may include removing the absorbent pad from the surface after a liquid is at least partially absorbed by the absorbent pad. In some instances, it may be determined that a liquid is at partially absorbed by the absorbent pad when the second absorption region defines a raised region such that the first absorption region is recessed relative to the second absorption region. 
     While particular embodiments of the present disclosure have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the disclosure. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this disclosure.