Patent Description:
The invention disclosed herein relates to a bonding system for controlling pieces traveling on a production line, specifically a bonding system for bonding a plurality of webs together. Although the description provided relates to diaper manufacturing, the method is easily adaptable to other applications. Although the description provided relates to bonding portions of diapers, the method is easily adaptable to other products, other disposable products, other diaper types and other portions of diapers.

Such bonding systems are described in patent application <CIT>, <CIT>, <CIT> and <CIT>.

The present invention relates to a bonding system having the features of claim <NUM>.

The current invention is a system for producing a disposable undergarment, with the lateral edges of the undergarment bonded by means of an ultrasonic horn. When a blank is formed for an individual undergarment, the lateral edges of opposing edges of the blank will form the seam. When the edges are sealed together, a seam is formed. The individual undergarments may be later separated along the seams.

Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention.

With attention to <FIG>, a bonding system <NUM> is disclosed wherein the positional accuracy of the bonding and quality of the bonding is improved over the prior art. As shown, the system <NUM> includes an ultrasonic bonder for bonding a plurality webs <NUM>, or a folded web <NUM> having a front side 12A and a back side 12B. The system <NUM> includes a first anvil 14A, a second anvil 14B, a first ultrasonic horn 16A, and a second ultrasonic horn 16B. The anvils 14A, 14B are each provided with an anvil insert <NUM> having a predetermined profile. The first and second anvils 14A, 14B are laterally spaced apart inline and in a machine direction.

The system <NUM> includes carrying means for carrying the webs <NUM> so that the webs <NUM> pass a first gap between the first anvil 14A and the first ultrasonic horn 16A and then a second gap between the second anvil 14B and the second ultrasonic horn 16B. The first and second ultrasonic horns 16A, 16B apply vibration energy to the web <NUM> simultaneously and in cooperation with a respective anvil 14A, 14B to bond a respective portion of the web <NUM> that is to be an end portion <NUM> of an individual finished article (not shown in these views). As mentioned, the first anvil 14A and the first ultrasonic horn 16A are provided inline from the second anvil 14B and the second ultrasonic horn 16B and are spaced apart a predetermined distance d1 that corresponds to the distance between bonds <NUM>. The predetermined distance d1 may be changed to accommodate various sizes of the finished product, since the distance d1 corresponds to the length of the individual article. Accordingly, the length of the individual article may be changed by adjusting the position of the first or second ultrasonic horn 16A, 16B with respect to the other ultrasonic horn 16A, 16B. Moreover, the system <NUM> includes a device for linear reciprocation of a selected anvil 14A, 14B and ultrasonic horn 16A, 16B relative another anvil 14A, 14B and ultrasonic horn 16A, 16B and to move in the direction of arrow A, (see <FIG>) and to thereby change the distance dl, d2 between a selected anvil 14A, 14B and horn 16A, 16B and the adjacent anvil 14A, 14B and horn 16A, 16B. Preferably, the selected anvil 14A, 14B and ultrasonic horn is 16A, 16B slidingly mounted to a base structure (not shown), and its movement manually or computer controlled, as understood by one skilled in the art. Since the distance dl, d2 intervals of bonding positions may be changed by changing the position of the first or second ultrasonic horn 16A, 16B, the present system may easily produce individual articles of various sizes. It is to be understood that while the view of <FIG> illustrates movement of the second ultrasonic horn 16B, the position of the first ultrasonic horn 16A may also or alternatively be changeable, as required by a specific application.

With attention to <FIG>, the present system <NUM> may be seen to further comprise a velocity-changing device for increasing and decreasing the moving velocity of the web <NUM>. The velocity-changing device preferably includes a first web festoon accumulator 24A having a first accumulator roller 30A, and a second web festoon accumulator 24B having a second accumulator roller 30B. The first web festoon accumulator 24A receives the webs <NUM> flowing from an upstream side and releases the webs toward the ultrasonic horns 16A, 16B while the second web festoon accumulator 24B receives the webs <NUM> from the ultrasonic horns 16A, 16B and moves the webs <NUM> toward a downstream side. The velocity-changing device further includes means for moving the first and second accumulator rollers 30A, 30B in a unison, linear manner to thereby change the velocity V1 of the web <NUM> received. As seen in <FIG>, when the first and second accumulator rollers 30A, 30B move in the direction of arrow B, the velocity V1 of the web <NUM> from the upstream side is moved to second, slower velocity V2, such that the dwell time of the web <NUM> during the bonding operation is adequate for proper bonding. The anvil rolls 14A, 14B are preferably synchronized such that the device <NUM> will produce two bonds <NUM> simultaneously during the slower V2 velocity. Once the web <NUM> is bonded, the accumulator rollers 30A, 30B move in the direction of arrow C (see <FIG>) and the webs <NUM> move at velocity V3 to be ultimately transported by the second web festoon accumulator 24B at the first V1 velocity and in a downstream direction.

The surfaces of the anvils 14A, 14B used in cooperation with the ultrasonic horns 16A, 16B may preferably include an anvil insert <NUM>, as is shown in <FIG>. The anvil insert <NUM> may include a seal surface, an embossing surface, or a combination thereof. The anvil insert <NUM> illustrated in these views includes a pair of spaced apart seal surfaces <NUM> having a recess <NUM> therebetween and wherein the seal surfaces <NUM> are provided with a series of canted rectangular patterns or teeth <NUM> thereon. The canted orientation of the rectangular pattern <NUM> provides both trailing edge and leading edge coverage in a cross-machine direction. This arrangement allows even wear on the horns 16A, 16B interfacing with the anvils 14A, 14B such that the need to re-grind worn horns 16A, 16B is greatly reduced. Moreover, the cost associated with anvil 14A, 14B assembly is reduced because the anvil 14A, 14B and the insert <NUM> may be manufactured separately and less material is required. Further, maintenance of the anvil 14A, 14B is easier and less costly since the user requires only a spare insert <NUM> rather than an entire anvil 14A, 14B when replacement is needed. Typical bond patterns produced by typical anvils (not shown) are not canted and are often merely a series of parallel rectangles (not shown). During use, these typical bond patterns may wear grooves into the surface of the horn 16A, 16B causing downtime for horn 16A, 16B maintenance. The pattern <NUM> disclosed in <FIG> reduces downtime for horn 16A, 16B maintenance. With particular reference to <FIG>, it may be seen that the canted arrangement of the rectangles or teeth <NUM>, creates a bond pattern that will evenly wear a corresponding ultrasonic horn 16A, 16B. As shown, the edges <NUM> of adjacent teeth <NUM> are parallel to one another for facile manufacture. Moreover, the teeth <NUM> are angled relative to the machine direction at a predetermined angle F (see <FIG>) that provides a following tooth <NUM> to fill in any gaps G (See <FIG>) existing between any preceding tooth <NUM>. The view of <FIG> illustrates this particular feature in greater detail. Depending on the geometry, such as width of gap between teeth <NUM> rows, width of gap between teeth <NUM>, and the like, the predetermined angle F may provide full coverage of the ultrasonic horn 16A, 16B to achieve the goal of even wear. While angling the teeth <NUM> provides more even wear of the ultrasonic horn 16A, 16B, structural liability of the teeth <NUM> may increase with the angle F. Structural integrity of the teeth <NUM> may be increased through the use of various radii between the teeth <NUM> (see <FIG> for example). By varying the radii between the teeth <NUM> such that each tooth has a small radius R2 on one side and a large radius R1 on the other, individual teeth <NUM> are more structurally sound and the chance of breaking a tooth <NUM> is greatly reduced. The anvil insert <NUM> of these views may be used to simultaneously bond adjacent article end portions <NUM>, while reserving a boundary between the sealed end portions for a later severing operation.

With attention to <FIG>, it may be seen that a bonding system <NUM> according to the present invention may include a first anvil 14A, a second anvil 14B, a third anvil 14C, a first ultrasonic horn 16A, a second ultrasonic horn 16B, and a third ultrasonic horn 16C. The anvils 14A, 14B, 14C may be each provided with an anvil insert <NUM> having a predetermined profile, as described above. The anvils 14A, 14B, 14C are laterally spaced apart inline and in a machine direction. As in the previous embodiment, the ultrasonic horns 16A, 16B, 16C apply vibration energy to the web <NUM> simultaneously and in cooperation with a respective anvil 14A, 14B, 14C to bond a respective portion of the web <NUM> that is to be an end portion <NUM> of an individual finished article (not shown in these views). As previously described, the first anvil 14A and the first ultrasonic horn 16A are provided inline from the second anvil 14B and the second ultrasonic horn 16B, with the third anvil 14C and the third ultrasonic horn 16C provided inline from the second anvil 14B and the second ultrasonic horn 16B. The anvils 14A, 14B, 14C with the corresponding horns 16A, 16B, 16C are spaced apart a predetermined distance d3 that corresponds to the distance between bonds <NUM>. The predetermined distance d3 may be changed to accommodate various sizes of the finished product, since the distance d3 corresponds to the length of the individual article. Accordingly, the length of the individual article may be changed by adjusting the position of the first, second, or third ultrasonic horn 16A, 16B, 16C with respect to any other ultrasonic horn 6A, 16B, 16C. Moreover, the system <NUM> includes a device for linear reciprocation of a selected anvil 14A, 14B, 14C and ultrasonic horn 16A, 16B, 16C relative to another anvil 14A, 14B, 14C and ultrasonic horn 16A, 16B, 16C and to move in the direction of arrow D, (see <FIG>) and to thereby change the distance d3, d4 between a selected anvil 14A, 14B, 14C and horn 16A, 16B, 16C and the adjacent anvil 114A, 14B, 14C and horn 16A, 16B, 16C. As in the previously described arrangement, a selected anvil 14A, 14B, 14C and ultrasonic horn is 16A, 16B, 16C is preferably slidingly mounted to a base structure (not shown), and the movement manually or computer controlled, as understood by one skilled in the art. Since the distance d3, d4 intervals of bonding positions may be changed by changing the position of the first, second, or third ultrasonic horn 16A, 16B, 16C the present system may easily produce individual articles of various sizes. It is to be understood that while the views of <FIG> illustrate movement of the first and third ultrasonic horns 16A, 16C, the position of the second ultrasonic horn 16B may also or alternatively be changeable, as required by a specific application. Moreover, the bonding system <NUM> may include any combination of fixed and moveable ultrasonic horns 16A, 16B, 16C, such as, but not limited to: one fixed ultrasonic horn, with two movable ultrasonic horns; two fixed ultrasonic horns and one movable ultrasonic horn; three fixed ultrasonic horns; and three movable ultrasonic horns, by way of non-limiting example.

<FIG> illustrate another arrangement of anvils and ultrasonic horns. In these views anvil pairs 114A, 114B are utilized rather that the single anvils 14A, 14B, 14C illustrated in previous views. Moreover, ultrasonic horn pairs 116A, 116B correspond to and cooperate with the anvil pairs 114A, 114B.

<FIG> illustrate an alternative arrangement and showing a vertical accumulator series <NUM> rather than the web festoon accumulator 24A, 24B and accumulator rollers 30A, 30B arrangement previously described. As shown, the accumulator series <NUM> may include any number of roll assemblies <NUM>. It is to be understood that while specific numbers and arrangements of assemblies <NUM> are shown in the Figures, any number and arrangement of roll assemblies <NUM> may be envisioned without departing from the invention. Moreover, while not specifically shown, it is to be understood that the accumulator series <NUM> shown in <FIG> may be used with any of the anvils 14A, 14B, 14C and ultrasonic horns 16A, 16B, 16C described and illustrated in previous views.

<FIG> illustrate an alternative arrangement similar to that of <FIG> but showing a horizontal accumulator series 140A. As shown, the accumulator series 140A may include any number of roll assemblies <NUM>. As in the arrangements shown n <FIG>, it is to be understood that the specific number and arrangement of assemblies <NUM> shown in the Figures should not be considered limiting, and any number and arrangement of roll assemblies <NUM> may be envisioned without departing from the invention. Moreover, while not specifically shown, it is to be understood that accumulator series 140A shown in <FIG> may be used with any of the anvils 14A, 14B, 14C and ultrasonic horns 16A, 16B, 16C described and illustrated in previous views.

With attention to <FIG>, another bonding system 10A may be seen. As shown, and similar to the system described with reference to <FIG>, system <NUM> includes an ultrasonic bonder for bonding a plurality webs <NUM>, or a folded web <NUM>. As in the previously described system, the system 10A shown in these views includes a first anvil 14A, a second anvil 14B, a first ultrasonic horn 16A, and a second ultrasonic horn 16B. The anvils 14A, 14B are each provided with an anvil insert 18A having a predetermined profile. The first and second anvils 14A, 14B are laterally spaced apart inline and in a machine direction. The anvils 14A, 14B seen in views are each further provided with a servo motor <NUM> such that the anvils 14A, 14B may be servo motor driven. As seen in <FIG>, the servo motor <NUM> functions to vary the revolution speed of the anvils 14A, 14B. The speed may be varied to thereby influence the dwell time of the anvil insert 18A against the web <NUM>. For example, and as shown in <FIG>, the revolution speed of the anvils 14A, 14B is varied such that, the revolution speed V1 of the anvils 14A, 14B from the upstream side may be slowed to second, slower velocity V2, such that the dwell time of the web <NUM> during the bonding operation is adequate for proper bonding. The anvils 14A, 14B are preferably synchronized such that the device 10A will produce two bonds <NUM> simultaneously during the slower V2 velocity. Once the web <NUM> is bonded, the anvils 14A, 14B accelerate to velocity V3 to be rotated back to the first V1 velocity, and in a downstream direction.

As in the previous embodiment, the system 10A shown in these views includes carrying means for carrying the webs <NUM> so that the webs <NUM> pass a first gap between the first anvil 14A and the first ultrasonic horn 16A and then a second gap between the second anvil 14B and the second ultrasonic horn 16B. The first and second ultrasonic horns 16A, 16B apply vibration energy to the web <NUM> simultaneously and in cooperation with a respective anvil 14A, 14B to bond a respective portion of the web <NUM> that is to be an end portion <NUM> (see <FIG>) of an individual finished article (not shown in these views). As mentioned, the first anvil 14A and the first ultrasonic horn 16A are provided inline from the second anvil 14B and the second ultrasonic horn 16B and are spaced apart a predetermined distance d1 that corresponds to the distance between bonds <NUM>. The predetermined distance d1 may be changed to accommodate various sizes of the finished product, since the distance d1 corresponds to the length of the individual article. Accordingly, the length of the individual article may be changed by adjusting the position of the first or second ultrasonic horn 16A, 16B with respect to the other ultrasonic horn 16A, 16B.

As in the previous embodiment, the surfaces of the anvils 14A, 14B used in cooperation with the ultrasonic horns 16A, 16B may include an anvil insert 18A, as is shown in <FIG>. The anvil insert 18A may include a seal surface, an embossing surface, or a combination thereof. The anvil insert 18A illustrated in these views includes a seal surface having a plurality of raised seal areas 26A and wherein the seal areas 26A are arranged in a pattern that is canted from the machine direction in an angle <NUM> (see <FIG>). Alternatively, and as seen in <FIG>, the pattern shown in <FIG> may be applied to the entire anvil <NUM>.

With reference to <FIG>, it may be seen that the surfaces of the anvils 14A, 14B may include another anvil insert 18B. As shown, and similar to the views of <FIG>, the seal surface of these views includes a plurality of raised seal areas 26B which are arranged in a pattern having an angle <NUM> (see <FIG>) relative to the anvil 14A, 14B. The anvil insert 18B is further curved in a helical configuration. As seen in <FIG>, the angle <NUM> of the seal area 26B pattern shown in <FIG> may be applied (inversely) to the entire unit (horn 16A, 16B and servo-driven anvil roll 14A, 14B) such that the angled seal surface 26B pattern is parallel to the machine direction when the horn 16A, 16B and servo-driven anvil roll 14A, 14B are canted in the cross direction by the inverse angle <NUM>. Alternatively, and as seen in <FIG>, the seal area 26B pattern shown in <FIG> may be applied to the surface of the entire anvil 140A in a helical pattern. As in the arrangement of <FIG>, the seal surface 26B pattern of anvil 140A is also parallel to the machine direction when the horn 16A, 16B and servo-driven anvil roll 140A is canted in the cross direction by the inverse angle <NUM> (see <FIG>). By canting the horn 16A, 16B and servo-driven anvil roll 140A in the angle <NUM> seen in <FIG> the pattern on the anvil 140A is applied in a parallel fashion of the web <NUM>.

The arrangements shown in the views of <FIG> increase the anvil 14A, 140A dwell time against the web <NUM> during bond formation and optimizes the force and power of the bond action. The angle <NUM> of the horn 16A, 16B and anvil 14A, 140A relative to the angle <NUM> of the seal surface 26B pattern increases the web <NUM> leading edge bond. The arrangement increases the typical time that the anvil 140A interacts with the horn 16A, 16B. Moreover, the arrangement minimizes certain known issues with consistent intermittent bond strength, such as spikes in power and weak leading edge bonds. The anvil and horn angle <NUM> in relation to the running web <NUM>, along with the helical pattern of the seal surface 26B pattern produce a bond that is perpendicular to the machine direction. The arrangement of the helical pattern on the anvil insert 26B and anvil 140A, along with the canted orientation of the anvil 14A, 14B, 140A and horn 16A, 16B relative the machine direction results in less area under the horn 16A, 16B at any point in the bond thereby allowing the potential for higher bond forces. The anvil 14A, 14B, 140A and horn 16A, 16B canted relative the machine direction may preferably be in the range of <NUM> - <NUM>°.

The angled orientation of the seal surface 26B pattern improves bond coverage in a cross-machine direction and further allows even wear on the horns 16A, 16B interfacing with the anvils 14A, 14B, <NUM> such that the need to re-grind worn horns 16A, 16B is greatly reduced. As mentioned, typical bond patterns produced by typical anvils (not shown) are not canted and are often merely a series of parallel rectangles (not shown). During use, these typical bond patterns may wear grooves into the surface of the horn 16A, 16B causing downtime for horn 16A, 16B maintenance. The patterns <NUM> disclosed in <FIG>, <FIG> reduce downtime for horn 16A, 16B maintenance. The anvil insert <NUM> in the views of <FIG> and <FIG> may be used to simultaneously bond adjacent article end portions <NUM>, while reserving a boundary between the sealed end portions for a later severing operation.

It is to be understood that the anvils 14A, 14B, 140A, 140B described above may be utilized singly or in pairs as illustrated, for example in <FIG>. Moreover, ultrasonic horns 16A, 16B may be paired correspond to and cooperate with paired anvils 14A, 14B, 140A, 140B.

Claim 1:
A bonding system (<NUM>) for bonding webs including:
a first anvil (14A) and a corresponding first ultrasonic horn (16A);
a second anvil (14B) and a corresponding second ultrasonic horn (16B), wherein each of the first anvil (14A) and the second anvil (14B) includes a seal surface (26B) having a predetermined profile;
wherein said first anvil (14A) and the second anvil (14B) are laterally spaced apart inline and in a machine direction;
wherein said first anvil (14A) and said second anvil (14B) are each provided with a respective servo motor;
characterised in that
said seal surface of each of the first anvil and the second anvil comprises an anvil insert having a predetermined seal surface pattern;
and in that said seal surface pattern is a helical pattern.