Patent Description:
Elastic nonwoven materials are utilized in a variety of articles including personal care articles (e.g., adult briefs, baby diapers, child/adult pull-on pants, contour fit hygiene products, etc.) and medical garments (e.g., masks, caps, gowns, footwear, etc.).

At least some conventional methods for fabricating elastic nonwoven materials include adhesively bonding elastic strands between layers of nonwoven fabric when the elastic strands are in tension. Once the elastic strands are permitted to contract, the elastic strands gather areas of the nonwoven fabric such that the nonwoven fabric functions with an elastic property. However, the durability of elastic nonwoven materials made by these conventional methods is less than desirable because the adhesive bonds are prone to creep, which can result in a loss of elasticity over time. Moreover, it can be overly expensive to fabricate elastic nonwoven materials using these conventional methods. It would be useful, therefore, to provide a system for fabricating a more durable elastic nonwoven material in a more cost effective manner. <CIT> discloses a known prior art.

Further embodiments are recited in the dependent claims.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, and in particular to <FIG>, a system for fabricating an elastic nonwoven material is indicated generally by <NUM>. The illustrated system <NUM> includes a supply station indicated generally by <NUM>, a processing station indicated generally by <NUM>, and a collection station indicated generally by <NUM>. Other suitable stations are also contemplated.

In the drawings, the supply station <NUM> includes a plurality of supply rolls each containing a nonwoven fabric, namely a first supply roll <NUM> containing a first nonwoven fabric <NUM> and a second supply roll <NUM> containing a second nonwoven fabric <NUM>. The supply station <NUM> also includes a plurality of supply spools each containing an elastic strand, namely a first supply spool <NUM> containing a first elastic strand <NUM>, a second supply spool <NUM> containing a second elastic strand <NUM>, a third supply spool <NUM> containing a third elastic strand <NUM>, and a fourth supply spool <NUM> containing a fourth elastic strand <NUM>. The elastic strands <NUM>, <NUM>, <NUM>, <NUM> may have any suitable cross-sectional shape that facilitates enabling the elastic strands <NUM>, <NUM>, <NUM>, <NUM> to function as described herein (e.g., a cross-sectional shape that is round, rectangular (e.g., relatively flat), square, etc.).

The illustrated processing station <NUM> includes a rotary ultrasonic bonding apparatus (indicated generally by <NUM>) for bonding the elastic strands <NUM>, <NUM>, <NUM>, <NUM> between the nonwoven fabrics <NUM>, <NUM> to make an elastic nonwoven material <NUM>, as set forth in more detail below. The collection station <NUM> may include any suitable device(s) for collecting the elastic nonwoven material <NUM> (e.g., a puller roll <NUM>). The supply station <NUM> may have any suitable quantity of supply rolls and supply spools having any suitable configuration that facilitates enabling the apparatus <NUM> to function as described herein.

<FIG> are various examples of the rotary ultrasonic bonding apparatus <NUM> according to the claimed invention. The apparatus <NUM> has an anvil module <NUM> and a horn module <NUM> that cooperate to perform a bonding operation of the elastic strands <NUM>, <NUM>, <NUM>, <NUM> between the nonwoven fabrics <NUM>, <NUM> as set forth in more detail below.

The horn module <NUM> includes a frame <NUM> on which are mounted a disc-like rotary horn <NUM>, a motor <NUM> for driving rotation of the horn <NUM> via a suitable drive train <NUM>, and a housing <NUM> which contains at least part of a vibration control unit (not shown) that causes the horn <NUM> to vibrate. The horn <NUM> has a face <NUM> with a substantially continuous contour (i.e., the horn face <NUM> has a contour that is substantially smooth (or uninterrupted) across its entire surface area). In other embodiments, the horn face <NUM> may have any suitable contour that facilitates enabling the horn <NUM> to function as described herein.

In the claimed invention , the vibration control unit (while not illustrated) can include at least one booster (e.g., a drive booster and an integral booster) mechanically connected to a converter, which is electrically connectable to a generator. The converter is capable of converting high frequency electrical energy supplied by the generator into mechanical energy (or vibration) that is selectively transmitted to the horn <NUM> across the booster(s). The booster(s) are capable of modifying (i.e., increasing or decreasing) the vibration transmitted to the horn <NUM> from the converter, such that the horn <NUM> (particularly, the face <NUM> of the horn <NUM>) vibrates while it rotates during a bonding operation, as set forth in more detail below. It is contemplated that the horn module <NUM> may have any suitable operational components arranged in any suitable manner that facilitates enabling the horn <NUM> to function as described herein.

The anvil module <NUM> includes a frame <NUM> on which are mounted a disc-like rotary anvil <NUM> and a motor <NUM> for driving rotation of the anvil <NUM> via a suitable drive train <NUM>. The anvil <NUM> has an annular face <NUM>, the contour of which is not continuous (i.e., is interrupted) as set forth in more detail below. The anvil module <NUM> is positioned relative to the horn module <NUM> such that the anvil face <NUM> is rotatable in close proximity to the horn face <NUM>, and vice versa, to facilitate ultrasonically bonding the elastic strands <NUM>, <NUM>, <NUM>, <NUM> between the nonwoven fabrics <NUM>, <NUM> when the elastic strands <NUM>, <NUM>, <NUM>, <NUM> are held in tension across apparatus <NUM>, as set forth in more detail below. As used herein, the term "close proximity" refers to when the anvil face <NUM> is either in contact with, or is minimally spaced apart from, the horn face <NUM> when the horn <NUM> is not ultrasonically vibrating.

The apparatus <NUM> may be configured such that at least one of the anvil module <NUM> and the horn module <NUM> is displaceable relative to the other via a suitable displacement mechanism operable either: (A) when the system <NUM> is offline and the horn <NUM> is at rest (i.e., when the horn <NUM> is not rotating or vibrating); or (B) when the system <NUM> is online and the horn <NUM> is active (i.e., when the horn <NUM> is rotating and vibrating).

With particular reference to <FIG> of the claimed invention, the apparatus <NUM> may be configured as a continuous-nip apparatus in which the horn module <NUM> is to be: (A) fixed in position relative to the anvil module <NUM> when the system <NUM> is online and the horn <NUM> is active; and (B) displaceable relative to the anvil module <NUM> when the system <NUM> is offline and the horn <NUM> is at rest. Such displacement is facilitated by a selectively actuatable pneumatic cylinder <NUM> (or other suitable linear actuator) that connects the frames <NUM>, <NUM> to one another. In this manner, the spacing between the horn face <NUM> and the anvil face <NUM> is adjustable primarily for servicing the apparatus <NUM> when the system <NUM> is offline.

Referring now to <FIG> and <FIG> of the claimed invention, the apparatus <NUM> may also be configured as an intermittent-nip apparatus in which the horn module <NUM> is displaceable relative to the anvil module <NUM> via a rotary camming device <NUM> when the system <NUM> is online and the horn <NUM> is active. The rotary camming device <NUM> has a follower <NUM> mounted to the horn module frame <NUM>, and a cam wheel <NUM> mounted to the anvil module frame <NUM> and rotatable via a servomotor <NUM>. The cam wheel <NUM> has an irregular camming surface <NUM> such that, when the cam wheel <NUM> is rotated via the servomotor <NUM>, the follower <NUM> rides along the irregular camming surface <NUM> to cyclically displace the horn module frame <NUM> relative to the anvil module frame <NUM> at a predetermined frequency. In this manner, the spacing between the horn face <NUM> and the anvil face <NUM>, and/or the frequency at which the horn face <NUM> contacts the anvil face <NUM>, are selectively adjustable. Other displaceable arrangements of the horn module <NUM> and the anvil module <NUM> are also contemplated without departing from the scope of this invention.

As shown in <FIG> and <FIG>, the apparatus <NUM> of the claimed invention may also include a pinching device <NUM>. In the illustrated embodiment, the pinching device <NUM> includes a base <NUM> and a roller <NUM> floatingly mounted to the base <NUM> via at least one biasing element <NUM>. The pinching device <NUM> also includes a bracket assembly <NUM> by which the base <NUM> and the roller <NUM> are mounted to at least one of the frame <NUM> and the frame <NUM>, such that the base <NUM> and the roller <NUM> are adjustable in at least two degrees of freedom (as set forth in more detail below) in relation to the anvil <NUM> to facilitate use of the pinching device <NUM> in conjunction with anvils of different sizes.

The illustrated bracket assembly <NUM> includes a first bracket <NUM> and a second bracket <NUM>. The first bracket <NUM> has at least one linear slot <NUM> through which a bolt <NUM> (which is fixed to either the frame <NUM> of the horn module <NUM> or the frame <NUM> of the anvil module <NUM>) extends, and along which the bolt <NUM> is slidable, thereby rendering the first bracket <NUM> translatable relative to the frame <NUM> and/or <NUM>. The second bracket <NUM> has at least one substantially arcuate slot <NUM> through which a bolt <NUM> (which is fixed to the first bracket <NUM>) extends, and along which the bolt <NUM> is slidable, thereby rendering the second bracket <NUM> rotatable relative to the first bracket <NUM>. The base <NUM> is mounted to the second bracket <NUM> such that the base <NUM> (and, therefore, the roller <NUM>) are rotatably adjustable in a first degree of freedom via rotation of the second bracket <NUM>, and are translatably adjustable in a second degree of freedom via translation of the first bracket <NUM>.

The position of the base <NUM> and, therefore, the roller <NUM> are fixable via the bolt <NUM> and the bolt <NUM> to achieve a desired pinching contact between the roller <NUM> and the anvil face <NUM>. For example, the base <NUM> and the roller <NUM> are oriented such that the biasing element <NUM> applies a biasing force oriented substantially perpendicular to a rotation axis of the anvil <NUM> when viewed as in <FIG>. In other embodiments, the pinching device <NUM> may have any suitable components arranged and movable (e.g., translatable and/or rotatable) in any suitable manner that facilitates enabling the pinching device <NUM> to perform the pinching action described herein (e.g., on any suitable bracket assembly that facilitates enabling the base <NUM> and the roller <NUM> to be adjustable in at least two degrees of freedom such as, for example, two translating degrees of freedom, or one translating degree of freedom and one rotating degree of freedom).

In this manner, the pinching device <NUM> limits the snap-back potential of elastic strands <NUM>, <NUM>, <NUM>, <NUM> that become severed between horn <NUM> and anvil <NUM> during a bonding operation. More specifically, the pinching device <NUM> effectively catches broken elastic strand(s) <NUM>, <NUM>, <NUM>, <NUM> between the roller <NUM> and the anvil <NUM> to prevent the broken elastic strands <NUM>, <NUM>, <NUM>, <NUM> from snapping back to their respective supply spool(s) <NUM>, <NUM>, <NUM>, <NUM>. Moreover, because the roller <NUM> rotates by virtue of being in contact with anvil <NUM>, any broken elastic strands <NUM>, <NUM>, <NUM>, <NUM> are caught at the interface of roller <NUM> and anvil <NUM> and are automatically fed back into the interface between horn <NUM> and anvil <NUM>. As such, the pinching device <NUM> serves as a self-threading device for broken elastic strands <NUM>, <NUM>, <NUM>, <NUM>.

Notably, the apparatus <NUM> may have any suitable quantity of anvil modules <NUM> and/or horn modules <NUM> that cooperate with one another to facilitate enabling the apparatus <NUM> to function as described herein. For example, as illustrated in the embodiment of <FIG>, the apparatus <NUM> may be configured with an anvil drum <NUM> in which a pair of anvils <NUM> are positioned such that the drum <NUM> has a pair of predefined, annular faces <NUM> that are spaced apart from one another. In this manner, the horn <NUM> of a separate horn module <NUM> is dedicated to each such anvil face <NUM>, thereby facilitating a bonding operation on confined regions of larger nonwoven fabrics on which only partial elasticity is desired (e.g., segments of these larger nonwoven fabrics on which elasticity is not desired may move along non-contact regions <NUM> of the drum <NUM> to avoid interaction with the associated horn(s) <NUM>).

To facilitate minimizing the occurrence of elastic strands <NUM>, <NUM>, <NUM>, <NUM> being cut between the horn <NUM> and the anvil <NUM> during a bonding operation, it is desirable to effectively hold the elastic strands <NUM>, <NUM>, <NUM>, <NUM> in place within notches of the anvil face <NUM> while the nonwoven fabrics <NUM>, <NUM> are bonded together between the horn <NUM> and the anvil <NUM>. At least the following operational parameters contribute to minimizing the occurrence of elastic strands <NUM>, <NUM>, <NUM>, <NUM> being cut during a bonding operation: (A) the specific energy source (e.g., the amplitude of vibration of the horn <NUM> and its pressure when contacting the anvil <NUM>); (B) the energy director (e.g., the geometry of the anvil face <NUM>); and (C) the material system (e.g., the decitex and tension of the elastic strands <NUM>, <NUM>, <NUM>, <NUM>, and the basis weight of the nonwoven fabrics <NUM>, <NUM>).

With respect to one such parameter (i.e., the geometry of the anvil face <NUM>), <FIG> is a laid-flat illustration of an anvil face <NUM> of the apparatus <NUM>. The anvil face <NUM> has a circumferential centerline axis <NUM> and a width dimension <NUM> oriented perpendicular to the axis <NUM>. The contour of the anvil face <NUM> is irregular (i.e., not continuous) along the axis <NUM>, in that the anvil face <NUM> defines a plurality of circumferentially spaced ridges <NUM>. For example, in some embodiments, each adjacent pair of ridges <NUM> may have a spacing (or pitch) measured along the axis <NUM> of between about <NUM>,<NUM> (<NUM>,<NUM> inch) and about <NUM>,<NUM> (<NUM> inch) (e.g., between about <NUM>,<NUM> and about <NUM>,<NUM>). While all adjacent pairs of ridges <NUM> on the anvil face <NUM> are substantially equally spaced apart from one another, it is contemplated that the spacing between adjacent pairs of ridges <NUM> may vary along the axis <NUM>.

Each ridge <NUM> extends substantially linearly across the circumferential axis <NUM> so as to span substantially the entire width <NUM> of the anvil face <NUM>. Each ridge <NUM> has an extension axis <NUM> oriented oblique to the circumferential axis <NUM>. As illustrated in <FIG>, each ridge <NUM> includes a plurality of lands <NUM> spaced along its extension axis <NUM> such that each adjacent pair of lands <NUM> is spaced apart by (or flank) a notch <NUM>. While the lands <NUM> and notches <NUM> are illustrated on only a select few of the ridges <NUM> in <FIG>, it is understood that all ridges <NUM> of anvil face <NUM> likewise have a set of lands <NUM> and notches <NUM> along their respective extension axes <NUM>. Notably, adjacent ones of the lands <NUM> of each ridge <NUM> are shaped such that the corresponding notch <NUM> defined therebetween is oriented substantially parallel to the circumferential axis <NUM> (i.e., the ridges <NUM> and the notches <NUM> each have a lengthwise dimension <NUM> that is oriented substantially parallel to the circumferential axis <NUM>).

The anvil face <NUM> may be configured for a continuous entrapment bonding operation. More specifically, in such embodiments, each of the ridges <NUM> has at least one notch <NUM> that is aligned in the width dimension <NUM> with a corresponding notch <NUM> of each other ridge <NUM>, and the lands <NUM> that flank each aligned notch <NUM> are spaced to create widthwise adjacent bonds in the nonwoven fabrics <NUM>, <NUM> that are close enough together in the width dimension <NUM> to permanently hold the associated elastic strand <NUM>, <NUM>, <NUM>, <NUM> in tension therebetween. As a result, after the bonding operation is complete and the nonwoven fabrics <NUM>, <NUM> are removed from the system <NUM>, at least one of the elastic strands <NUM>, <NUM>, <NUM>, <NUM> is subsequently permitted to contract between circumferentially adjacent rows of bonds, but not between the widthwise adjacent bonds through which the elastic strand(s) <NUM>, <NUM>, <NUM>, <NUM> extend. The entrapment bonding operation is therefore said to be continuous in the sense that at least one of the elastic strands <NUM>, <NUM>, <NUM>, <NUM> is caused to be permanently held in tension between each widthwise adjacent pair of bonds through which it extends.

In a continuous entrapment configuration of the anvil face <NUM>, the lands <NUM> and the notches <NUM> of each ridge <NUM> have sizes (and, therefore, spacings) relative to one another that are substantially the same as those of all other ridges <NUM> on the anvil face <NUM>. The notches <NUM> are generally U-shaped or generally V-shaped, such that the sidewalls of the lands <NUM> that flank each notch <NUM> may, when viewed from a cross-sectional profile of the notch <NUM> as shown in <FIG>, form a wedge angle therebetween of about <NUM>° (i.e., the sidewalls may be about parallel to one another) and about <NUM>° (e.g., between about <NUM>° and about <NUM>°). Notches <NUM> of other shapes are also contemplated.

If the elastic strands <NUM>, <NUM>, <NUM>, <NUM> have a decitex of between about <NUM> and about <NUM>, and if the nonwoven fabrics <NUM>, <NUM> have a grammage (gsm) of between about <NUM> and <NUM>, the lands <NUM> may have lengths at their peaks of between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> inch, <NUM>,<NUM> inch) (e.g., between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch)), and widths at their peaks of between about <NUM>,<NUM> and <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch) (e.g., between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch). Also, in that example, the notches <NUM> may have: depths measured from the peaks of their flanking lands <NUM> of between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch) (e.g., between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch)); widths measured at the peaks of their flanking lands <NUM> of between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch) (e.g., between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch)); and widths measured at their bases of between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch) (e.g., between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch)).

By providing the lands <NUM> and the notches <NUM> with the dimensions of the above example, the anvil face <NUM> facilitates improved gripping of the elastic strands <NUM>, <NUM>, <NUM>, <NUM> in the notches <NUM> and, therefore, facilitates preventing the elastic strands <NUM>, <NUM>, <NUM>, <NUM> from withdrawing out of the notches <NUM> to reduce the occurrence of severed elastic strands <NUM>, <NUM>, <NUM>, <NUM>. Other suitable sizes for the lands <NUM> and the notches <NUM> are also contemplated.

The anvil face <NUM> may be configured for an intermittent entrapment bonding operation, such that the lands <NUM> that flank at least one of the notches <NUM> are spaced to create widthwise adjacent bonds in the nonwoven fabrics <NUM>, <NUM> that are not close enough together in the width dimension <NUM> to permanently hold the associated elastic strand <NUM>, <NUM>, <NUM>, <NUM> in tension therebetween. As a result, after the bonding operation is complete and the nonwoven fabrics <NUM>, <NUM> are removed from the system <NUM>, the corresponding elastic strand <NUM>, <NUM>, <NUM>, <NUM> is subsequently permitted to contract between the widthwise adjacent bonds through which it extends such that its tension between those widthwise adjacent bonds is substantially relieved. The entrapment bonding operation is therefore said to be intermittent in the sense that at least one of the elastic strands <NUM>, <NUM>, <NUM>, <NUM> is not permanently held in tension between all pairs of widthwise adjacent bonds through which it extends.

In an intermittent entrapment configuration of the anvil face <NUM>, the anvil face <NUM> may be provided with a plurality of distinct circumferential regions <NUM> such that a dimension of a notch <NUM> (and, therefore, the lands <NUM> that flank it) on a ridge <NUM> in at least one circumferential region <NUM> is different than a dimension of a widthwise aligned notch <NUM> (and, therefore, the lands <NUM> that flank it) on a ridge <NUM> in at least one other circumferential region <NUM>.

For example, each ridge <NUM> in a plurality of first circumferential regions <NUM>, <NUM> may have at least one notch <NUM> that is sized differently as compared to at least one notch <NUM> that is widthwise aligned therewith on ridges <NUM> in a plurality of second circumferential regions <NUM>, <NUM> interspaced between the first circumferential regions <NUM>, <NUM>. In this example, within the first circumferential regions <NUM>, <NUM>, the notches <NUM> may be sized with larger widths (like in <FIG>) such that the elastic strands <NUM>, <NUM>, <NUM>, <NUM> do not later become entrapped across (i.e., are later permitted to slip between) the widthwise adjacent bonds created at widthwise adjacent lands <NUM> on ridges <NUM> in these first circumferential regions <NUM>, <NUM>. Whereas, within the second circumferential regions <NUM>, <NUM>, the notches <NUM> may be sized with smaller widths (like in <FIG>) such that the elastic strands <NUM>, <NUM>, <NUM>, <NUM> later become entrapped across (i.e., are not later permitted to slip between) the widthwise adjacent bonds created at widthwise adjacent lands <NUM> on ridges <NUM> in the second circumferential regions <NUM>, <NUM>.

More specifically, in this example, at least one ridge <NUM> in each second circumferential region <NUM>, <NUM> may have its notches <NUM> sized in the manner set forth above for the continuous entrapment example, while at least one ridge <NUM> in each first circumferential region <NUM>, <NUM> may have its notches <NUM> sized with a width (as measured at the peaks of its flanking lands <NUM>) of between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch) (e.g., between about <NUM>,<NUM> and about <NUM>,<NUM> (<NUM>,<NUM> and <NUM>,<NUM> inch) in some embodiments; or about <NUM> inches in one particular embodiment). Thus, adequate slippage of the elastic strands <NUM>, <NUM>, <NUM>, <NUM> across at least one ridge <NUM> in each first circumferential region <NUM>, <NUM> is facilitated, especially when the elastic strands <NUM>, <NUM>, <NUM>, <NUM> have a decitex of between about <NUM> and about <NUM>, and when the nonwoven fabrics <NUM>, <NUM> have a grammage (gsm) of between about <NUM> and <NUM>.

In both a continuous entrapment configuration and an intermittent entrapment configuration, the anvil face <NUM> may have a plurality of distinct widthwise segments <NUM>, wherein each widthwise segment <NUM> has lands <NUM> and/or notches <NUM> of comparatively different sizes. For example, in one particular embodiment according to the claimed invention as illustrated by <FIG>, the anvil face <NUM> may have a first widthwise segment <NUM> with lands <NUM> that define notches <NUM> of a first width to suit elastic strands <NUM>, <NUM>, <NUM>, <NUM> of a first decitex, and a second widthwise segment <NUM> with lands <NUM> that define notches <NUM> of a second width that is less than the first width to suit elastic strands <NUM>, <NUM>, <NUM>, <NUM> of a second decitex that is less than the first decitex. Thus, each widthwise segment <NUM>, no matter whether it is configured for continuous or intermittent entrapment, may be sized to accommodate elastic strands <NUM>, <NUM>, <NUM>, <NUM> of different sizes.

The anvil face <NUM> may have ridges <NUM> that extend non-linearly across the circumferential axis <NUM>. For example, in <FIG>, the anvil face <NUM> may define a plurality of ridges <NUM> each with a curvilinear axis (e.g., a substantially arcuate axis <NUM>). Notably, these non-linear ridges <NUM> may have the same dimensions for the lands <NUM> and the notches <NUM> as for the substantially linearly extending ridges <NUM> set forth above, including the same dimensional variations amongst circumferential and widthwise regions <NUM>, <NUM> as is set forth above with respect to the substantially linearly extending ridges <NUM>.

<FIG> illustrates an elastic nonwoven material <NUM> fabricated using the system <NUM>. An intermittent entrapment bonding process was performed on the nonwoven fabrics <NUM>, <NUM> (with elastic strands <NUM>, <NUM> sandwiched therebetween) using one of the examples of the apparatus <NUM> set forth above. The anvil <NUM> utilized to fabricate the material <NUM> has an anvil face <NUM> with notches <NUM> that vary in size across circumferential regions <NUM> as set forth above. In this manner, with the nonwoven fabrics <NUM>, <NUM> and the elastic strands <NUM>, <NUM> held in tension across the apparatus <NUM>, the horn face <NUM> and the anvil face <NUM> created bonds <NUM> at locations corresponding to the lands <NUM> of the anvil face <NUM>.

Once the bonded nonwoven fabrics <NUM>, <NUM> (and the elastic strands <NUM>, <NUM> sandwiched therebetween) were subsequently removed from the system <NUM>, the tension in the elastic strands <NUM>, <NUM> was partly relieved such that segments of each elastic strand <NUM>, <NUM> were permitted to contract to create material <NUM>. More specifically, a first segment <NUM> of each elastic strand <NUM>, <NUM> became entrapped between adjacent rows of bonds <NUM> that corresponded to the ridges <NUM> which defined notches <NUM> of smaller widths. Whereas, a second segment <NUM> of each elastic strand <NUM>, <NUM> was permitted to slip across widthwise adjacent bonds <NUM> in rows that corresponded to the ridges <NUM> which defined notches <NUM> of larger widths. In this manner, the nonwoven fabrics <NUM>, <NUM> were caused to gather in areas <NUM> of the material <NUM> that have widthwise adjacent bonds <NUM> of closer spacing (but not in areas <NUM> that have widthwise adjacent bonds <NUM> of greater spacing) to effectively provide the material <NUM> with an elastic property. Notably, if a continuous entrapment operation had been utilized instead of an intermittent entrapment operation, the material <NUM> would not have second segments <NUM> that are permitted to slip, but would instead only have first segments <NUM> such that the nonwoven fabrics <NUM>, <NUM> would gather along the entire material <NUM>.

The rotary ultrasonic bonding systems and methods set forth herein are utilized to directly entrap tensioned elastic within a nonwoven fabric without the use of adhesives, thereby providing various functional and commercial advantages. The systems and methods eliminate the complex adhesive delivery systems and costly adhesive materials associated with adhesive bonding processes, and the systems and methods provide a simpler, cleaner, and safer (e.g., cooler in temperature) production environment, with lower power consumption and lower material costs. Also, various functional deficiencies of adhesively bonded materials are eliminated, including adhesive bleed-through, stiffening, and creep that are common in conventional adhesively bonded materials. Thus, lower-cost nonwoven/film substrates and elastic materials can be utilized.

Moreover, the systems and methods set forth herein facilitate a more continuous production sequence (i.e., increased process uptime) due, at least in part, to the lack of: adhesive-related cleaning operations; adhesive system delivery/reliability issues; heated equipment cooldown periods in advance of maintenance events; cold-start periods; and re-heat or purge-calibrate events. Additionally, a more continuous production sequence is further facilitated by the automatic threading (or self-threading) of severed elastic strands when the system is online, as well as the use of continuously-running, over-the-end elastic spools.

Additionally, the systems and methods set forth herein are usable to attach (e.g., entrapment) elastic strands while also performing other elastic processing steps such as cutting/chopping processes, seaming processes, edge trimming processes, etc. The systems and methods are further adaptable to existing capital asset bases to provide retrofit capability (with customizable configurations if desired), as well as quicker grade-change capability as the attachment zone length changes via a software interface.

The systems and methods also facilitate maximizing elastic performance. For example, the systems and methods facilitate lowering tension at elongation as compared to other attachment methods (e.g., the systems and methods can provide a nearly pure elastic response for stress vs. strain when at least some substrates are utilized). The systems and methods also facilitate minimizing creep (or loss of performance) (e.g., the systems and methods produce elastic materials that are more robust in the face of temperature, time, and end-user solvents (e.g., emollients)) due, at least in part, to the fact that the elastic strands can be entrapped in a thermoplastic substrate, as opposed to being attached to a substrate with a susceptible intermediate binder material.

The systems and methods further facilitate customized aesthetics and functional benefits. For example, gathers are produced by a bonding pattern and/or strand-feed positioning such that size, shape, and frequency are selectable. Also, zoned tension is enabled, in that tension can be controlled by an elastic segment depending upon the desired fabric configuration (e.g., depending upon the desired cross-direction orientation within fabric (among lanes) and/or longitudinal orientation within fabric (within lanes)). Curved attachment is also facilitated if desired. Furthermore, controlled slip/creep for adjustable fit is facilitated, with intermittent or continuous attachment of elastic to the substrate being selectable to enable placement/zoning of live elastic and non-elasticized segments.

In addition to the systems and methods set forth above, other systems are also contemplated. For example, non-rotary systems of attachment (e.g., stationary (or blade) ultrasonic horns, heat, pressure, etc.) are contemplated. Also, in combination with the rotary examples set forth above, adhesive systems may be usable. Moreover, latent elastics may be usable instead of tensioned elastics in some embodiments. Then too, the systems and methods facilitate curving (or shifting) elastic strands with less occurrence of breakage, and the systems and methods further facilitate generating a matrix of tensions (e.g., a checkerboard effect), differential ruffling, dead zones, and/or simultaneous incorporation of elastic strands of different decitex.

Claim 1:
An apparatus (<NUM>) for fabricating an elastic nonwoven material, said apparatus comprising:
a rotary ultrasonic horn (<NUM>); and
a rotary anvil (<NUM>) positionable in close proximity to the rotary ultrasonic horn, wherein the rotary anvil has a face (<NUM>) with a width and a circumferential axis (<NUM>), the face having a plurality of ridges (<NUM>) each of which defines a plurality of interspaced lands (<NUM>) and notches (<NUM>), the ridges extending obliquely across the circumferential axis, and the notches oriented substantially parallel to the circumferential axis.