Patent Publication Number: US-9895271-B2

Title: Method and apparatus for attaching components to absorbent articles

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 13/929,843 filed on Jun. 28, 2013, which claims priority to 61/665,928 filed on Jun. 29, 2012, which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to methods and apparatuses for manufacturing disposable absorbent articles, and more particularly, methods and apparatuses for attaching components, such as waistbands, side panels, cuffs, or other components to disposable absorbent articles. 
     BACKGROUND OF THE INVENTION 
     Along an assembly line, diapers and various types of other absorbent articles may be assembled by adding components to and otherwise modifying an advancing, continuous web of material. For example, in some processes, advancing webs of material are combined with other advancing webs of material. In other examples, individual components created from advancing webs of material are combined with advancing webs of material, which, in turn, are then combined with other advancing webs of material. Webs of material and component parts used to manufacture diapers may include: back sheets, topsheet, absorbent cores, front and/or back ears, fastener components, and various types of elastic webs and components such as leg elastics, barrier leg cuff elastics, and waist elastics. Once the desired component parts are assembled, the advancing web(s) and component parts are subjected to a final cut to separate the web(s) into discrete diapers or other absorbent articles. The discrete diapers or absorbent articles may also then be folded and packaged. 
     Various methods and apparatuses may be used for attaching different components to the advancing web. Some of the methods and apparatuses relate to securing waistbands, and more particularly, elastic waistbands to an advancing web. In some processes, elastic waistbands are adhered to an advancing web in a stretched condition. However, some existing methods and apparatuses add cost and complexity to manufacturing processes. For example, the waistband material may be advanced in a first direction, stretched, rotated, and advanced in a second direction before being applied to an advancing web. In addition, in order to join waistbands advancing in the cross direction to a continuous web advancing in the machine direction, some processes may intermittently direct an advancing web toward the advancing waistband, which directs the advancing web away from the machine direction. As a result, the web may be mechanically strained to the point of rupture. In some processes, waistbands may be joined to the advancing web such that the waistbands are spaced apart along the machine direction of the advancing web. The spacing between adjacent waistbands may change from one size absorbent article to another size absorbent article. Such processes are not easily configurable to accommodate changes in the spacing and/or size of the waistbands. As a result, in order to change a process from producing one size absorbent article to producing a different size absorbent article, equipment may need to be altered or replaced, which in turn adds machine and labor costs to the process. 
     It may be desirable to provide a process for attaching components of absorbent articles advancing in a cross direction to a continuous web of absorbent articles advancing in a machine direction. It may be desirable to provide a process and apparatus for joining components of absorbent articles to advancing webs while minimizing the time the advancing web is directed away from the machine direction. It may also be desirable to provide a process and apparatus adaptable for joining components of absorbent articles of various sizes and spacing to an advancing web. 
     SUMMARY OF THE INVENTION 
     Aspects of the present disclosure involve an apparatus for applying discrete components, such as waistbands, cut from a first substrate to a second substrate. The apparatus may comprise a drum having an outer circumferential surface and a cutter positioned to cut the first substrate on the outer circumferential surface of the drum into a plurality of the discrete components. The apparatus may include a conveyor for positioning the second substrate proximate to, but not in contact with, the outer circumferential surface of the drum. The apparatus may also comprise a programmable servo motor having a shaft, wherein the shaft continuously rotates at a variable angular velocity in a single direction. The servo motor is configured to rotate the shaft in a first phase and a second phase. The shaft is constrained to rotate from a first angular position to a second angular position in a first time in the first phase and the shaft is thereafter constrained to rotate from the second angular position back to the first angular position in a second time in the second phase. The apparatus may also include a tamper member associated with the shaft of the servo motor. When the shaft rotates in the first phase, the tamper member travels from a first position to a second position to displace a selected portion of the second substrate into contact with the discrete component on the outer circumferential surface of the drum. 
     Aspects of the present disclosure may involve an apparatus for applying discrete components of a first substrate to a target area of a second substrate. The apparatus may comprise a programmable servo motor having a shaft, wherein the shaft continuously rotates at a variable angular velocity in a single direction. The servo motor is programmed to rotate the shaft in a first phase and a second phase. The shaft is constrained to rotate from a first angular position to a second angular position in a first time in the first phase and the shaft is constrained to rotate from the second angular position to the first angular position in a second time in the second phase. The apparatus may include a crank member connected with the shaft and a connector link connected with the crank member. The apparatus includes a tamper member connected with the connector link. The tamper member is positioned proximate to the second substrate in line with a discrete component of the first substrate. The second substrate may comprise a target area. When the shaft rotates in the first phase, the tamper member travels from a first position to a second position to displace the target area of the second substrate into contact with the discrete component. 
     Aspects of the present disclosure also include a method for applying discrete components of a first substrate to a second substrate, the method comprising the steps of: rotating a drum about an axis of rotation, the drum having an outer circumferential surface; advancing the first substrate onto the outer circumferential surface of the drum; advancing the second substrate proximate to the outer circumferential surface of the drum, the second substrate having a first surface and a second surface, wherein the second surface comprises a target area; cutting the first substrate into discrete components on the outer circumferential surface of the drum, the discrete components having a first surface and an opposing second surface; continuously rotating a shaft of a motor at a variable angular velocity in a single direction, wherein the motor is configured to rotate the shaft in a first phase and a second phase, wherein the shaft is constrained to rotate from a first angular position to a second angular position in a first time in the first phase, wherein the shaft is constrained to rotate from the second angular position to the first angular position in a second time in the second phase; shifting a tamper member from a first position to a second position toward the second substrate and the outer circumferential surface of the drum as the shaft of the motor rotates in the first phase; displacing the second substrate such that the target area of the second substrate contacts the first surface of a discrete component on the drum; and shifting the tamper member from the second position back to the first position as the shaft of the motor rotates in the second phase. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an apparatus for joining discrete components to a continuous length of absorbent articles. 
         FIG. 2A  is a plan view of a continuous length of absorbent articles from  FIG. 1  taken along line A-A before discrete waistbands are affixed by the apparatus. 
         FIG. 2B  is a plan view of a continuous length of absorbent articles from  FIG. 1  taken along line B-B after discrete waistbands are affixed by the apparatus. 
         FIG. 2C  is a plan view of a continuous length of absorbent articles having discrete waistbands. 
         FIG. 2D  is a plan view of a continuous length of absorbent articles having discrete waistbands. 
         FIG. 2E  is a plan view of an exemplary absorbent article having two discrete waistbands. 
         FIG. 2F  is a plan view of an exemplary absorbent article having one discrete waistband. 
         FIG. 2G  is a plan view of an exemplary absorbent article having one discrete waistband. 
         FIG. 3A  is a perspective view of a tamper apparatus. 
         FIG. 3B  is an elevation view of a point D on the tamper apparatus of  FIG. 3A  showing the reciprocating movement of the tamper member in the vertical direction in a defined trajectory. 
         FIG. 4A  is a schematic, perspective view showing a shaft of a motor rotating from a first angular position to a second angular position, and back to a first angular position. 
         FIG. 4B  is schematic, perspective view of a shaft of a motor in a first angular position connected with a crank member in a first position. 
         FIG. 4C  is a schematic, perspective view of a shaft of a motor in a second angular position connected with a crank member in a second position. 
         FIG. 5  is an elevation view of a tamper apparatus in a first configuration. 
         FIG. 6  is an elevation view of a tamper apparatus in a second configuration. 
         FIG. 7  is a plot of the vertical position of point D from the outer circumferential surface of the drum with the motor operating at a variable angular velocity over one revolution overlaid with a plot of the vertical position of point D from the outer circumferential surface of the drum with a motor operating at a constant angular velocity over one revolution. 
         FIG. 8  is a plot of the vertical position of point D from the outer circumferential surface of the drum with the motor operating at a variable angular velocity over one revolution overlaid with a plot of the angular velocity of the shaft of the motor over one revolution. 
         FIG. 9  is a perspective side view of a tamper apparatus. 
         FIG. 10  is a plan view of a disposable absorbent article having a discrete waistband and is partially cut away to show the construction of and various features that may be included in a disposable absorbent article. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     This application claims priority to U.S. Provisional Application Ser. No. 61/665,928, filed Jun. 29, 2012, which is hereby incorporated by reference in its entirety. 
     The following term definitions may be useful in understanding the present disclosure: 
     “Absorbent article” is used herein to refer to consumer products whose primary function is to absorb and retain soils and wastes. 
     “Diaper” is used herein to refer to an absorbent article generally worn by infants and incontinent persons about the lower torso. 
     “Disposable” is used herein to describe absorbent articles which generally are not intended to be laundered or otherwise restored or reused as an absorbent article (e.g., they are intended to be discarded after a single use and may also be configured to be recycled, composted or otherwise disposed of in an environmentally compatible manner). 
     “Disposed” is used herein to mean that an element(s) is formed (joined and positioned) in a particular place or position as a macro-unitary structure with other elements or as a separate element joined to another element. 
     As used herein, “joined” encompasses configurations whereby an element is directly secured to another element by affixing the element directly to the other element, and configurations whereby an element is indirectly secured to another element by affixing the element to intermediate member(s) which in turn are affixed to the other element. 
     “Substrate” is used herein to describe a material which is primarily two-dimensional (i.e. in an XY plane) and whose thickness (in a Z direction) is relatively small (i.e. 1/10 or less) in comparison to its length (in an X direction) and width (in a Y direction). Non-limiting examples of substrates include a layer or layers or fibrous materials, films and foils such as plastic films or metallic foils that may be used alone or laminated to one or more web, layer, film and/or foil. As such, a web is a substrate. 
     “Nonwoven” refers herein to a material made from continuous (long) filaments (fibers) and/or discontinuous (short) filaments (fibers) by processes such as spunbonding, meltblowing, and the like. Nonwovens do not have a woven or knitted filament pattern. 
     “Machine direction” (MD) is used herein to refer to the direction of a second substrate through a process. 
     “Cross direction” (CD) is used herein to refer to a direction that is generally not parallel to, and usually perpendicular to, the machine direction in the XY plane of the material. 
     “Elastic,” “elastomer” or “elastomeric” refers to materials exhibiting elastic properties, which include any material that upon application of a force to its relaxed, initial length can stretch or elongate to an elongated length more than 10% greater than its initial length and will substantially recover back to about its initial length upon release of the applied force. The term “inelastic” refers herein to any material that does not fall within the definition of “elastic” above. 
     “Stretchable” refers to materials that are capable of extending in at least one direction to a certain degree without undue rupture. 
     The present disclosure relates to methods and apparatuses for joining substrates. As discussed in more detail below, the process may be utilized in an absorbent article assembly configuration wherein discrete components, such as waistbands, are held on an outer surface of a rotating drum. A tamper apparatus may include a tamper member that directs a target area of an advancing substrate into contact with the discrete components on the drum. Adhesive may be applied to the discrete components and/or substrate to adhere the substrate and the discrete components together. The tamper member may be operatively connected with the shaft of a servo motor. In some configurations, a crank member may be connected with the motor shaft and connected with a connector link. The connector link operatively connects the tamper member with the crank member. The motor shaft may be configured to continuously rotate at a variable angular velocity in a single direction. In some instances, the servo motor is configured to rotate the motor shaft in a first phase and a second phase, wherein the motor shaft is constrained to rotate from a first angular position to a second angular position in a first time in the first phase. In addition, the shaft may be constrained to rotate from the second angular position to the first angular position in a second time in the second phase. When the shaft rotates in the first phase, the tamper member travels from a first position to a second position to displace a selected portion of the substrate into contact with a discrete component on the drum. When the shaft rotates in the second phase, the tamper member travels from the second position to the first position to move away from the substrate. 
     As discussed below, the tamper apparatus may include various links and/or tracks to define the travel path of the reciprocating movement of the tamper member. For example, some configurations may include guide links that pivotally connect the tamper member to a base. The tamper apparatus may include a compressible member disposed along a bottom surface of the tamper member. In some configurations, the tamper member may be slidingly connected with guide bars that define a straight line reciprocating travel path. 
     In some joining operations, a drum is rotated about an axis of rotation and a first substrate advances onto an outer circumferential surface of the drum. A conveyor concurrently advances a second substrate in a machine direction adjacent to the drum. The drum may be oriented such that the first substrate is advanced in a cross direction with respect to the second substrate. The tamper apparatus is positioned adjacent the second substrate such that the second substrate is between the tamper apparatus and the outer circumferential surface of the drum. Adhesive may be applied to the first substrate prior to or while the first substrate is advancing on the drum. While advancing on the outer circumferential surface of the drum, the first substrate may be cut into discrete components. As the drum rotates to position the discrete components adjacent the second substrate on the drum, the servo motor drives the tamper member toward the outer circumferential surface of the drum. The tamper member directs the second substrate into contact with the discrete component on the outer circumferential surface of the drum. Adhesive on the discrete component attaches the discrete components to the second substrate. The servo motor then drives the tamper member away from the outer circumferential surface of the drum and the second substrate continues advancing in the machine direction with the discrete component attached. The process is repeated to join each discrete component to the second substrate. As such, the discrete components are spaced apart from each other discrete component on the second substrate in the machine direction. 
     The servo motor is configured to rapidly drive the tamper member toward and away from the outer circumferential surface of the drum in order to minimize the contact time between the tamper member and the advancing second substrate. As such, the motor angular velocity is greatest when the tamper member is relatively near to the outer circumferential surface of the drum. The angular velocity of the motor increases in the first phase as the tamper member moves toward the drum and decreases in the second phase as the tamper member moves away from the drum. By operating the motor at variable angular velocities, the motor can be configured to slow down when the tamper member is away from the outer circumferential surface of the drum to allow a subsequent discrete component time to advance adjacent the second substrate and the drum. Furthermore, the servo motor can be re-programmed to account for changes in the desired outputs without the need to change or alter existing equipment. Additionally, the mechanism connected to the servo motor is relatively smaller in size compared to a mechanical cam mechanism. 
     It is to be appreciated that although the methods and apparatuses herein may be configured to join various types of substrates and discrete components, the methods and apparatuses herein are discussed below in the context of manufacturing absorbent articles. In particular, the methods and apparatuses are discussed in the context of joining discrete elastic components to a continuous length of absorbent articles. While the present disclosure relates mainly to addition of elastic components such as waistbands to diapers, it is to be appreciated that the methods and apparatuses disclosed herein can also be applied to other discrete components used on diapers as well as other types of absorbent articles. For example, elastic components can include pre-stretched ears or side panels, cuffs placed in a side saddle process where the product&#39;s waist regions are parallel to the machine direction, or other components requiring stretch in the cross direction. In other applications, the discrete elastic components can comprise elastic topsheets for a diaper cut from a substrate stretched in the cross direction before being connected with other diaper components, such as a backsheet. In addition, other applications may include the addition of various inelastic components such as backsheets, topsheet, absorbent cores, front and/or back ears, and fastener components. 
     It is to be appreciated that the first substrate may be constructed from various types of materials. For example, the first substrate may include a combination of layered elastic substrates such as elastic films, poly films, and nonwovens. In some examples, the first substrate may be constructed from a single elastic or poly film. In yet other examples, the first substrate may be constructed from a single layer nonwoven. It should also be appreciated that second substrate may include various components of an assembled absorbent article, such as, for example, a topsheet and/or a backsheet. Various types of suitable materials for various diaper components are discussed in more detail below with reference to an example diaper embodiment. 
     As previously mentioned, the apparatuses and methods disclosed herein may be configured to join waistbands to a continuous length of absorbent articles as the absorbent articles are being manufactured. For example, as shown in  FIG. 1 , a first substrate  104  may continuously advance onto an outer circumferential surface  124  of a rotating drum  112  in a stretched state. Concurrently, a second substrate  106  may advance in a machine direction MD adjacent the outer circumferential surface  124  of the drum  112 . The drum  112  may be oriented such that the first substrate is advanced in a cross direction CD with respect to the machine direction of the second substrate  106 . Adhesive  113  may be applied by adhesive applicator  117  to the first substrate  104  before the first substrate  104  advances onto the drum  112 . The drum  112  may rotate at a velocity such that the outer circumferential surface  124  of the drum  112  travels at the same speed as the first substrate  104 . The drum  112  may be configured with vacuum openings  103  for applying vacuum force to hold the first substrate  104  on the outer circumferential surface  124 , while maintaining cross directional stretch in the first substrate  104 . While the first substrate  104  is advancing on the drum  112 , a cutter  116 , shown in the form of a rotating knife roll  116   a  for purposes of illustration, may cut the first substrate  104  into discrete components  102 . Vacuum force may be used to maintain stretch in the discrete components  102  after being cut. While it is shown that the first substrate  104  is cut by a rotating knife roll  116   a , it is to be appreciated that various other cutters may be used. 
     With continued reference to  FIG. 1 , the discrete components  102  are individually transferred from the drum  112  to the second substrate  106  with a tamper apparatus  136 . A conveyor  202  may advance the second substrate  106  in the machine direction MD. The conveyor  202  may be configured to periodically slow or stop the movement of the second substrate  106  in the machine direction MD. For example, the conveyor  202  may include a localized speed varying apparatus  203 , such as shown in  FIG. 1 . It is to be appreciated that various types of localized speed varying apparatuses may be used. Exemplary localized speed varying apparatuses may include those described in U.S. Pat. No. 5,693,165 issued to Schmitz on Dec. 2, 1997; U.S. Pat. No. 6,596,108 issued to Mccabe on Jul. 22, 2003; and U.S. Patent Publication No. 2010/0252603 published on Oct. 7, 2010. As the second substrate  106  is stopped, the tamper apparatus  136  moves the second substrate  106  into contact with a discrete component  102 , subsequently removing the discrete component  102  from the outer circumferential surface  124  of the drum  112  and attaching the discrete component  102  to the second substrate  106  with adhesive  113 . Vacuum may be intermittently interrupted in order to assist removal of the discrete component  102  from the outer circumferential surface  124  of the drum  112 . The tamper apparatus  136  then moves away from the second substrate  106 , while the second substrate  106  and the discrete component  102  continue advancing in the machine direction MD. The attachment process is repeated to join each discrete component  102  to the second substrate  106 . Exemplary processes for attaching elastic components to absorbent articles are described in U.S. Provisional Patent Application No. 61/665,930. 
       FIG. 2A  shows the continuous length of second substrate  106  before attaching the discrete components. As shown in  FIG. 2A , the second substrate  106  may have a plurality of target areas  115  positioned where the discrete components are to be attached to the second substrate  106 . As shown in  FIG. 2B , the discrete components  102 , shown as discrete waistbands  194  for purposes of illustration, may be joined at each target areas  115 . Once the discrete waistbands  194  are joined, the second substrate  106 , and thus the discrete waistband  194 , may be cut in the cross direction CD to create a first waistband  194   a  on an absorbent article  104  and a second waistband  194   b  on a subsequently advancing absorbent article  104 . In some exemplary configurations, as shown in  FIGS. 2C and 2D , the second substrate  106  may be cut adjacent to the discrete waistband  194 , either before or after the discrete waistband  194 , thereby creating an absorbent article  150   a  having only one discrete waistband  194 . In some exemplary configurations, absorbent articles  150   a  may have one discrete waistband  194  as shown in  FIGS. 2F and 2G , or may have two discrete waistbands  194   a  and  194   b  as shown in  FIG. 2E . It is to be appreciated that the absorbent articles  150   a  may have discrete waistbands arranged in various configurations. As discussed below, the method steps disclosed herein can be carried out in different ways by various types of mechanisms. 
       FIG. 3A  shows a detailed perspective view of an embodiment of a tamper apparatus  136  that may be used to join discrete components to a substrate. As shown in  FIG. 3A , the tamper apparatus  136  may include a tamper member  220  operatively connected to a motor  222  at a shaft  224  of the motor  222 . The tamper apparatus  136  may also include a crank member  226  that is rotatably connected to the shaft  224  of the motor  222  in a first portion  228  of the crank member  226  and operatively connected to a connector link  240  in a second portion  230 . The connector link  240  operatively connects the tamper member  220  to the crank member  226 . The tamper apparatus  136  may also include a set of guide links  232  that pivotally connect the tamper member  220  to a base  234 . The tamper apparatus  136  may include a compressible member  250  operatively connected to a bottom surface  248  of the tamper member  220 . 
     With reference to  FIGS. 1 and 3A , during operation, the motor  222  is configured to continuously rotate the shaft  224  of the motor  222  at a variable angular velocity in a single direction. A second substrate  106  may advance in the machine direction MD by a conveyor  202 , while the discrete components  102  advance in the cross direction CD on a rotating drum  112 , such that the second substrate  106  is positioned between the tamper apparatus  136  and the discrete component  102  on the outer circumferential surface  124  of the drum  112 . As the shaft  224  rotates, the crank member  226  rotates in the same direction as the shaft  224  of the motor  222 . Subsequently, the connector link  240  and the guide links  232  pivot, causing the tamper member  220  to move in the vertical direction, Y. The shaft  224  may continuously rotate in a single direction, causing the tamper member  220  to reciprocate toward and away from the drum  112  in the vertical direction, Y.  FIG. 3B  shows a point D of the tamper apparatus  136  from  FIG. 3A  reciprocating in the vertical direction, Y, in a defined trajectory, T. Following the vertical positioning of point D demonstrates the reciprocating movement of the tamper apparatus  136  as it moves toward and away from the drum  112 . 
       FIG. 4A  shows a schematic view of a motor shaft rotating from a first angular position to a second angular position, and back to a first angular position. With reference to  FIGS. 3A, 4A, 4B, and 4C , the motor  222  is configured to rotate the shaft  224  in a first phase  260  and a second phase  262 . In the first phase  260 , the shaft  224  of the motor  222  rotates from a first angular position  264  to a second angular position  266  in a first time, causing the crank member  226  to rotate from a first position  280  shown in  FIG. 4B  to a second position  282  shown in  FIG. 4C . In the second phase  262 , the shaft  224  of the motor  222  rotates from a second angular position  266  back to the first angular position  264  in a second time, causing the crank member  226  to concurrently rotate from a second position  282  to a first position  280 . As discussed in more detail below, as the crank member  226  rotates from a first position  280  to a second position  282 , the tamper member  220  shifts toward the drum from a first position to a second position. Subsequently, the crank member  226  rotates from a second position  282  to a first position  280  and the tamper member  220  shifts away from the drum. 
     A motor  222  may be used to drive the tamper apparatus  136  such as shown in  FIG. 3A . In particular, the motor  222  may, for example, be a programmable servo motor. For high speed manufacturing processes, such as in the production of absorbent articles, the variable angular velocity and requisite accelerations may require a motor with low inertia and high torque to inertia properties. As shown in  FIG. 3A , the servo motor  222  includes a gear box  223  to provide speed and torque conversions to the tamper apparatus  136 . An exemplary programmable servo motor  222  is manufactured by Rockwell Automation, Inc. of Milwaukee, Wis., under the designation MPL-B330P. It is to be appreciated that one of ordinary skill in the art could program the servo motor if provided with the desired tamper member outputs. 
     With continuing reference to  FIG. 3A , the tamper apparatus  136  may also include a crank member  226 . The crank member  226  may be defined by a first portion  228  and a second portion  230 . The first portion  228  of the crank member  226  may be operatively connected to the shaft  224  of the motor  222  such that the crank member  226  rotates with the shaft  224  of the motor  222  in the same direction. The second portion  230  of the crank member  226  may be rotatably connected to a first end  241  of the connector link  240 . In some exemplary configurations, bearings may be used to connect the second portion  230  of the crank  226  to the first end  241  of the connector link  240 . 
     The tamper apparatus  136  may also include a tamper member  220  as shown in  FIG. 3A . The tamper member  220  may have a first portion  244  and a second portion  246 . The second portion  246  of the tamper member  220  may define a bottom surface  248 . The first portion  244  of the tamper member  220  may be operatively connected to a second end  242  of the connector link  240 . The second portion  246  of the tamper member  220  may be substantially perpendicular to the first portion  244  of the tamper member  220 , forming a substantially T-shaped member. The bottom surface  148  of the tamper member  220  may be contoured to match the contour of the outer circumferential surface of the drum. The bottom surface  248  of the tamper member  220  may be larger than a discrete component such that the tamper member  220  may press the second substrate against the entire discrete component. It is to be appreciated that a tamper member  220  configured for one size discrete component may be used to attach discrete components of various sizes. In some exemplary configurations, the tamper member  220  may be made from a light-weight metal material such as, for example, aluminum or titanium. 
     With reference to  FIG. 3A , the tamper apparatus  136  may also include a compressible member  250  disposed along the bottom surface  248  of the tamper member  220 . The compressible member  250  may be made of a material such as, for example, foam or rubber that compresses upon application of pressure to the compressible member. In some exemplary configurations, the compressible member  250  may have void spaces  252  such as shown in  FIG. 3A . The compressible member may have an arcuate shape to match the contour of the outer circumferential surface of the drum. It is to be appreciated that a bottom surface  254  of the compressible member  250  may include a skin  256  to prevent the tamper apparatus  136  from sticking to the second substrate. The skin  256  may be made of a non-stick material such as urethane for example. 
     The tamper apparatus  136  may also include guide links  232  as shown in  FIG. 3A . One end of each guide link may be operatively connected to the first portion  244  of the tamper member  220 . The other end of each guide link  232  may be operatively connected to a base  234 . While  FIG. 3A  shows two guide links  232 , it is to be appreciated that fewer or greater than two guide links  232  may be used. 
     In operation, a continuous length of second substrate is advanced in the machine direction MD and discrete components are advanced in the cross-direction CD proximate to the tamper apparatus as shown in  FIG. 1 . The second substrate  106  advances in the machine direction MD proximate to the tamper apparatus  136  by a conveyor  202 . The second substrate  106  may be defined by a first surface  107  and a second surface  108 . At the same time as the second substrate  106  advances in the machine direction MD, discrete components  102  advance on the outer circumferential surface  124  of the rotating drum  112  in the cross direction CD such that the second substrate  106  is between the tamper apparatus  136  and the discrete components  102  on the outer circumferential surface  124  of the drum  112 . The discrete components  102  may be defined by a first surface  109  and a second surface  110 . As discussed in more detail below, the tamper apparatus  136  is configured to reciprocate from a first configuration to a second configuration and back to a first configuration to join the first surface  109  of the discrete components  102  to the second surface  108  of the second substrate  106 . 
       FIG. 5  shows a front elevation view of a tamper apparatus  136  in a first configuration  284 . In a first configuration  284 , the crank member  226  is in a first position  280  and the tamper member  220  is in a first position  207 , positioned away from the second substrate  106  and the outer circumferential surface  124  of the drum  112 .  FIG. 6  shows a front elevation view of a tamper apparatus  136  in a second configuration  286 . In a second configuration  286 , the crank member  226  is in a second position  282  and the tamper member  220  is in a second position  209 , pressing the second substrate  106  against the discrete band  102  on the outer circumferential surface  124  of the drum  112 . 
     As shown in  FIGS. 5 and 6 , the contour of the bottom surface  248  of the tamper member  220  may match the contour of the outer circumferential surface  124  of the drum  112  such that the second substrate  106  uniformly presses the discrete components  102  between the tamper member  220  and the outer circumferential surface  124  of the drum  112 . It is to be appreciated the discrete components may advance by a conveyor or a variety of other apparatuses having a contours different than that of the outer circumferential surface of the drum. 
     Referring to  FIGS. 1, 3A-6 , the servo motor  222  continuously rotates the shaft  224  of the motor  222  at a variable angular velocity in a single direction. In one revolution, the tamper apparatus  136  starts in a first configuration  284 . In the first configuration  284 , the shaft  224  of the motor  222  starts at a first angular position  264  and the crank member  226  also starts in first position  280 . As the shaft  224  of the motor  222  rotates, the crank member  226  rotates in the same direction. The second portion  230  of the crank member  226  rotates in a circular path around the shaft  224  of the motor  222 . At the same time, the bearings that connect the crank member  226  to the connector link  240  cause the first end  241  of the connector link  240  to also rotate in a circular path around the shaft  224  of the motor  222 . As the first end  241  of the connector link  240  rotates, the tamper member  220  reciprocates downward in the vertical direction toward the first surface  107  of the second substrate  106  and the set of guide links  232  pivot. The guide links  232  limit the movement of the tamper member  220  to a defined trajectory, T, as the tamper member  220  moves toward the drum  112 . The tamper member  220  contacts the first surface  107  of the second substrate  106  as the shaft  224  of the motor  222  approaches the second angular position  266 , causing the second substrate  106  to be pressed against the first surface  109  of the discrete component  102  on the outer circumferential surface  124  of the drum  112 . The tamper apparatus  136  is in the second configuration  286  when the tamper member  220  presses the second substrate  106  against the discrete component  102  on the outer circumferential surface  124  of the drum  112 . The adhesive  113  on the first surface  109  of the discrete component  102  acts to adhere the second surface  108  of the second substrate  106  to the first surface  109  of the discrete component  102 . To complete one revolution, the tamper apparatus  136  shifts from the second configuration  286  back to the first configuration  284 . The shaft  224  of the motor  222  continues rotating from the second angular position  266  back to the first angular position  264  and the crank member  226  rotates from a second position  282  to a first position  280 . The tamper apparatus  136  continuously rotates back and forth from the first configuration  284  to the second configuration  286  through multiple revolutions in order to join subsequent discrete components to the second substrate  106 . 
     With reference to  FIGS. 2A and 3A , the tamper member  220  may be configured to displace the target area  115  of the second surface  108  of the second substrate  106  into contact with the first surface  109  of the discrete component  102 . In particular, the tamper member  220  may displace the first surface  107  of the second substrate  106  and press the target area  115  of the second surface  108  of the second substrate  106  against the first surface  109  of the discrete component  102  on the outer circumferential surface  124  of the drum  112 . 
     The shaft of the motor is configured to continuously rotate at a variable angular velocity, causing the velocity of the tamper member in the vertical direction, Y, to change during each revolution.  FIG. 7  shows a graph  400  of the vertical position of point D from the outer circumferential surface of the drum with the motor operating at a variable angular velocity over one revolution.  FIG. 7  also includes graph  500  of the vertical position of point D from the outer circumferential surface of the drum with a motor operating at a constant angular velocity over one revolution. With regard to graphs  400  and  500 , the tamper member compresses against the drum at zero meters. Time is represented on the x-axis. As shown in  FIG. 7 , for each revolution, the tamper member is relatively near the outer circumferential surface of the drum for a shorter period of time when the motor is operating at a variable angular velocity compared to a motor operating at a constant angular velocity. A motor configured to rotate the shaft at a variable angular velocity can speed up and slow down through one revolution in order to limit the time the tamper member directs the second substrate toward the outer circumferential surface of the drum. Whereas, when the motor is programmed to drive the shaft of the motor with a constant angular velocity, the motor must drive the shaft at a higher constant angular velocity in order to limit the time the motor is contacting the outer circumferential surface of the drum. However, speeding up a motor operating at a constant angular velocity decreases the total time of one revolution. In some exemplary configurations, the total time for one revolution may be preselected based upon the spacing requirements of the discrete components on the second substrate. In that case, operating the motor at a variable angular velocity may limit the time the tamper member contacts the second substrate while also maintaining the preselected amount of time between attachment of adjacent discrete components. 
       FIG. 8  shows a graph  600  of the vertical position of point D from the outer circumferential surface of the drum with the motor operating at a variable angular velocity over one revolution.  FIG. 8  also shows a graph  700  of the angular velocity of the shaft of the motor over one revolution. Time is represented on the x-axis. As shown in  FIG. 8 , as the tamper member approaches the outer circumferential surface of the drum at zero meters, the angular velocity of the shaft of the motor is increasing. Once the tamper member is in the second position, the angular velocity is at the highest angular velocity for each revolution. The angular velocity of the shaft of the motor then decreases as the tamper member shifts away from the outer circumferential surface of the drum. The angular velocity of the motor is at lowest angular velocity when the tamper member is furthest from the drum at the first position. 
       FIG. 9  shows a perspective side view of an embodiment of a tamper apparatus. As shown in  FIG. 9 , the tamper apparatus  326  may include a servo motor  322  having a shaft  324 . The shaft of the motor  322  is operatively connected to a crank member  326  at one end of the crank member  326 . The opposite end of the crank member  326  is rotatably connected to a connector link  340 . The connector link  340  is also rotatably connected to a tamper member  320 . The tamper member  320  may be connected with two guide bars  332  in order to limit the trajectory of a point on the tamper member  320  to a straight line. The tamper member  320  may also include a compressible member  350  having a skin  356 . 
     With reference to  FIG. 1 , the conveyor apparatus  202  may be in the form of a localized speed varying apparatus  203  that may slow or stop the second substrate  106  in the machine direction MD. As the second substrate  106  is stopped or slowed, the tamper apparatus  136  is able to more precisely join the discrete component  102  to the second substrate  106 . While the second substrate  106  is temporarily stopped in the machine direction MD, the drum  112  continues to rotates in the cross direction CD while the tamper apparatus  136  contacts the second substrate  106  and discrete component  102  against the outer circumferential surface  124  of the drum  112 . It is to be appreciated that the compressible member  250  may deform while the tamper apparatus  136  compresses the second substrate  106  against the discrete component  102  on the outer circumferential surface  124  of the drum  112 . As a result, the discrete component  102  may remain in the same cross-directional position relative to the second substrate  106  even though the drum  112  continues rotating in the cross direction CD. 
     A number of different products may be manufactured in accordance with the methods described herein. For the purposes of a specific illustration,  FIG. 10  shows one example of a disposable absorbent article  150  in the form of a diaper  152  that may include a discrete component  102  attached thereto in accordance with the present disclosure. In particular,  FIG. 10  is a plan view of one embodiment of a diaper  152  including a chassis  154  shown in a flat, unfolded condition, with the portion of the diaper  152  that faces a wearer oriented towards the viewer. A portion of the chassis structure is cut-away in  FIG. 10  to more clearly show the construction of and various features that may be included in exemplary configurations of the diaper. 
     As shown in  FIG. 10 , the diaper  152  includes a chassis  154  having a first ear  156 , a second ear  158 , a third ear  160 , and a fourth ear  162 . As discussed above, while the present disclosure discusses joining discrete components in the form of waistbands to absorbent articles, it is to be appreciated that the tamper apparatus may be used to join other discrete components such as ears  156 ,  158 ,  160 , and  162 , for example, to absorbent articles. To provide a frame of reference for the present discussion, the chassis is shown with a longitudinal axis  164  and a lateral axis  166 . The chassis  154  is shown as having a first waist region  168 , a second waist region  170 , and a crotch region  172  disposed intermediate the first and second waist regions. The periphery of the diaper is defined by a pair of longitudinally extending side edges  174 ,  176 ; a first outer edge  178  extending laterally adjacent the first waist region  168 ; and a second outer edge  180  extending laterally adjacent the second waist region  170 . As shown in  FIG. 10 , the chassis  154  includes an inner, body-facing surface  182 , and an outer, garment-facing surface  184 . 
     As shown in  FIG. 10 , the chassis  154  of the diaper  152  may include an outer covering layer  186  including a topsheet  188  and a backsheet  190 . An absorbent core  192  may be disposed between a portion of the topsheet  188  and the backsheet  190 . As discussed in more detail below, one or more of the regions may be stretchable and may include an elastomeric material or layered elastic substrate as described herein. As such, the diaper  152  may be configured to adapt to a specific wearer&#39;s anatomy upon application and to maintain coordination with the wearer&#39;s anatomy during wear. 
     Although the first and second ears  156 ,  158  as well as the third and fourth ears  160 ,  162  shown in  FIG. 10  are illustrated as being integrally formed with the chassis  154 , it is to be appreciated that other embodiments may include ears that are discrete elements connected with the chassis. In some embodiments, the ears are configured to be stretchable. The ears may also include one or more fastener elements adapted to releasably connect with each other and/or other fastener elements on the chassis. A more detailed discussion of stretchable ears can be found in U.S. Pat. Nos. 4,857,067; 5,151,092; 5,674,216; 6,677,258; 4,381,781; 5,580,411; and 6,004,306. The ears may also include various geometries and arrangements of stretch zones or elements, such as discussed in U.S. Pat. Publication Nos. US 2005/0215972A1 and US 2005/0215973A1. 
     As shown in  FIG. 10 , the diaper  152  may include leg cuffs  196  that may provide improved containment of liquids and other body exudates. The leg cuffs  196  may be disposed in various ways on the diaper  152 . For example, the leg cuffs  196  may be disposed on the outer, garment-facing surface  184  of the chassis  154 ; the inner, body-facing surface  182 ; or between the inner and outer facing surfaces  182  or  184 . Leg cuffs  196  may also be referred to as leg bands, side flaps, barrier cuffs, or elastic cuffs. U.S. Pat. No. 3,860,003 describes a disposable diaper that provides a contractible leg opening having a side flap and one or more elastic members to provide an elasticized leg cuff (a gasketing cuff). U.S. Pat. Nos. 4,808,178 and 4,909,803 describe disposable diapers having “stand-up” elasticized flaps (barrier cuffs). U.S. Pat. Nos. 4,695,278 and 4,795,454 describe disposable diapers having dual cuffs, including gasketing cuffs and barrier cuffs. 
     The diaper may be provided in the form of a pant-type diaper or may alternatively be provided with a re-closable fastening system, which may include fastener elements in various locations to help secure the diaper in position on the wearer. For example, fastener elements may be located on the first and second ears and may be adapted to releasably connect with one or more corresponding fastening elements located in the second waist region. It is to be appreciated that various types of fastening elements may be used with the diaper. In one example, the fastening elements include hook &amp; loop fasteners, such as those available from 3M or Velcro Industries. In other examples, the fastening elements include adhesives and/or tap tabs, while others are configured as a macrofastener or hook (e.g., a MACRO or “button-like” fastener). Some exemplary fastening elements and systems are disclosed in U.S. Pat. Nos. 3,848,594; 4,662,875; 4,846,815; 4,894,060; 4,946,527; 5,151,092; and 5,221,274. Additional examples of fasteners and/or fastening elements are discussed in U.S. Pat. Nos. 6,251,097 and 6,432,098; and U.S. Patent Publication Nos. 2007/0078427 and 2007/0093769. Other fastening systems are described in more detail in U.S. Pat. Nos. 5,595,567; 5,624,427; 5,735,840; and 5,928,212. The fastening system may also provide a means for holding the article in a disposal configuration as disclosed in U.S. Pat. No. 4,963,140. 
     Components of the disposable absorbent article (i.e., diaper, disposable pant, adult incontinence article, sanitary napkin, pantiliner, etc.) described in this specification can at least partially be comprised of bio-sourced content as described in US 2007/0219521A1 Hird, et al published on Sep. 20, 2007, US 2011/0139658A1 Hird, et al published on Jun. 16, 2011, US 2011/0139657A1 Hird et al published on Jun. 16, 2011, US 2011/0152812A1 Hird et al published on Jun. 23, 2011, US 2011/0139662A1 Hird, et al published on Jun. 16, 2011, and US 2011/0139659A1 Hird, et al published on Jun. 16, 2011. These components include, but are not limited to, topsheet nonwovens, backsheet films, backsheet nonwovens, side panel nonwovens, barrier leg cuff nonwovens, super absorbent, nonwoven acquisition layers, core wrap nonwovens, adhesives, fastener hooks, and fastener landing zone nonwovens and film bases. 
     In at least one exemplary configuration, a disposable absorbent article component comprises a bio-based content value from about 10% to about 100% using ASTM D6866-10, method B, in another embodiment, from about 25% to about 75%, and in yet another embodiment, from about 50% to about 60% using ASTM D6866-10, method B. 
     In order to apply the methodology of ASTM D6866-10 to determine the bio-based content of any disposable absorbent article component, a representative sample of the disposable absorbent article component must be obtained for testing. In at least one embodiment, the disposable absorbent article component can be ground into particulates less than about 20 mesh using known grinding methods (e.g., Wiley® mill), and a representative sample of suitable mass taken from the randomly mixed particles. 
     The absorbent article may also include discrete components  102   a  and  102   b  such as shown in  FIG. 10  in the form of first and second waistbands  194   a  and  194   b . The first and second waistbands  194   a  and  194   b  may provide improved fit and waste containment. The first and second waistbands  194   a  and  194   b  may be located in the first waist region  168  and/or the second waist region  170 . The first and second waistbands  194   a  and  194   b  may be configured to elastically expand and contract to dynamically fit the wearer&#39;s waist. 
     The first and second waistbands  194   a  and  194   b  can be incorporated into the diaper in accordance with the methods discussed herein and may extend at least longitudinally outwardly from the absorbent core  192  and generally form at least a portion of the first and/or second outer edges  178 ,  180  of the diaper  152 . In addition, the first and second waistbands  194   a  and  194   b  may extend laterally to include the ears. While the first and second waistbands  194   a  and  194   b  or any constituent elements thereof may comprise one or more separate elements affixed to the diaper, the first and second waistbands  194   a  and  194   b  may be constructed as an extension of other elements of the diaper, such as the backsheet  190 , the topsheet  188 , or both the backsheet  190  and the topsheet  188 . In addition, the first and second waistbands  194   a  and  194   b  may be disposed on the outer, garment-facing surface  184  of the chassis  154 ; the inner, body-facing surface  182 ; or between the inner and outer facing surfaces. It is to be appreciated that the first and second waistbands  194   a  and  194   b  shown in  FIG. 10  may comprise the same materials and/or may have the same structure. While in other exemplary configurations, the first and second waistbands  194   a  and  194   b  may comprise different materials and/or may have different structures. The first and second waistbands  194   a  and  194   b  may be constructed in a number of different configurations including those described in U.S. Patent Application No. 61/499,294; and U.S. Patent Publication Nos. 2007/0142806; 2007/0142798; and 2007/0287983. 
     The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.” 
     Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
     While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.