CN117794722A

CN117794722A - System and method for sealing parts using ultrasonic transducers and wiper head motion

Info

Publication number: CN117794722A
Application number: CN202280055126.1A
Authority: CN
Inventors: 里奥·克林斯坦; 彼得·瓦斯科; 罗伯特·爱德华·阿尔达兹; 约瑟夫·雷; 安德鲁·杰曼
Original assignee: Duken Ias Ltd
Current assignee: Duken Ias Ltd
Priority date: 2021-08-16
Filing date: 2022-08-15
Publication date: 2024-03-29
Also published as: EP4387834A1; WO2023022988A1; JP2024532819A

Abstract

The system consists of two welding heads, two transducers, a memory and a controller. The first welding head comprises a first part contact surface, and the second welding head comprises a second part contact surface and is positioned relative to the first welding head so that the part to be welded can be clamped between the two contact surfaces. The controller is configured such that ultrasonic energy generated by the first transducer is applied to the first part contact surface through the first horn to cause vibration thereof, the first horn is moved in one direction at a first time, while ultrasonic energy generated by the second transducer is applied to the second part contact surface through the second horn to cause vibration thereof, and the second horn is moved in the other direction.

Description

System and method for sealing parts using ultrasonic transducers and wiper head motion

Cross Reference to Related Applications

U.S. patent application Ser. No. 17/403,653 entitled "System and method for sealing parts Using ultrasonic transducer and scraping bonding tool movement (Systems and Methods Using an Ultrasonic Transducer and Scrubbing Horn Motion to Seal a Part)" filed on 8/16 of 2021, the entirety of which is incorporated herein by reference, claims the benefit and priority of this application.

Background

Certain types of packages or containers may have complex sealing interfaces along which different numbers of layers of material are to be sealed. In some applications, the seal must be hermetic, gas-tight, or liquid-tight without any leakage. Conventional techniques for sealing these interfaces are cumbersome, expensive, and may require multiple seals at the same seal to complete, which takes a long time for each article to be sealed. Some preparation or manipulation of the article and/or its sealing interface must also be performed prior to the formation of the seal. These preparations or operations require additional time during the sealing process.

Typically, these articles may be composed of plastic or polyethylene materials or film coated materials of these materials (e.g., liquid cardboard), such as pillow packs, flow packs, and cartons or other containers, such as rooftop milk cartons (table top). To seal these articles, conventional methods may require different machines to seal different materials, take a relatively long time, and may require multiple processes to resolve the leak-proof seal, also suffer from rejects due to inconsistent seals, unsealing, channel leakage, and in addition, are difficult to resolve for certain seal shapes, particularly narrow seal seals, and require extensive maintenance due in part to their complexity and number of moving parts.

In conventional ultrasonic welding, an ultrasonic triplet is driven and the part is compressed between the triplet and the stationary anvil. For some applications, it is challenging to use only a single triplet configuration because the part may have multiple layers or other unusual geometries and may require multiple welds on the same part to accomplish a high quality seal or weld.

Roof bags or other sealed packaging applications with non-uniform layers (such as 4-2-4-5 layers, with the seal length being transverse) show the disadvantages of using a single triplet. Assuming that each layer of carton material will absorb or attenuate about 10% of the applied ultrasonic energy/amplitude, when conventional welding passes through 4-5 layers, only about 50% of the ultrasonic energy/amplitude remains on the final layer, which is insufficient to produce a reliable seal. If the force or amplitude or time is increased to compensate for this energy loss, there is a risk of overspray of the 2-layer area and possible burning of the outer surface, leaving a visual mark on the product.

Circular or elliptical interfaces, such as ports or ports, are very challenging to seal using conventional ultrasonic welding techniques. In general, conventional techniques require many bonding tools (e.g., up to four) and multiple repeated movements of the bonding tools, e.g., three or more steps, to seal these types of parts. These configurations are bulky, complex, and create delays in the manufacturing process by having to repeat the ultrasonic motion multiple times to perform their welding or sealing tasks. Accordingly, a solution to these and other problems is needed. Aspects of the present disclosure relate to the use of single-process ultrasonic welding to meet these needs, such as the needs of roof boxes and other seals.

Parts made of metal can be deformed using a mold to deform the metal into the desired shape. Examples include wire drawing, deep drawing, rolling, extrusion, and forging processes. Some conventional processes utilize lubricants applied externally to the mold part interface to facilitate deformation of the metal through the mold. Conventional processes leave marks on the surface of the metal that is deformed by the die, and the production efficiency of the deformation process depends on the speed at which the metal can deform and the force applied when it is pressed within the die. There is therefore a need to find better solutions.

Pillow bags or sacks or similar containers may be made of flexible materials such as plastics or nonwoven films, polyesters printed onto aluminum and then laminated onto polyethylene, metals including aluminum, metal foils, fabrics, films, polyethylene coated fiberboard or liquid cardboard, and the like. When the packaging material is moved onto the rollers, the portions between adjacent bags need to be sealed to securely contain the bags or contents of the bags. Conventional processes typically bag seal and then cut portions between adjacent bags to singulate the pouches. First, these double post-seal cutting actions introduce latency to the throughput of the entire bag assembly and sealing process. Second, the rollers must be suspended long enough to form a seal between adjacent pouches, and the throughput is directly dependent on the speed at which the seal is formed. Accelerating this sealing process will increase throughput. Performing the sealing and cutting operations simultaneously or nearly simultaneously will further increase throughput.

Disclosure of Invention

According to one aspect of the present disclosure, an ultrasonic welding system for sealing together multiple layers of a part includes: a first ultrasonic welding triplet including a first welding head having a first welding surface and a second ultrasonic welding triplet including a second welding head having a second welding surface opposite the first welding surface to define a gap therebetween, wherein the gap is configured to receive a seal cross-section along a part; a drive unit operatively coupleable to the first and second ultrasonic welding triplets and configured to move the first welding surface relative to the second welding surface; one or more controllers operably coupled to the first ultrasonic welding triplet, the second ultrasonic welding triplet, and the drive unit, the one or more controllers operably configured to: the drive unit is caused to squeeze the first and second welding surfaces of the first and second welding heads toward each other until the first and second welding surfaces are in contact with the part and thereby apply a first path of ultrasonic energy to the part via the first welding head and a second path of ultrasonic energy to the part via the second welding head such that the frequencies and phases of the first and second paths of ultrasonic energy are synchronized when the first and second paths of ultrasonic energy are simultaneously applied to both sides of the part, thereby sealing along the part seal cross section.

The frequency may be between 15kHz and 70 kHz. The element may be a roof pack having a different number of layers, i.e. a different number of layers along the roof seal cross-section. Alternatively, the element is a roof pack having a different number of layers arranged across the longitudinal direction of the roof. The amplitude of the first path of ultrasonic energy may be the same as or different from the amplitude of the second path of ultrasonic energy.

The system may further include a first generator that generates a first path of ultrasonic energy and a second generator that generates a second path of ultrasonic energy, wherein the first generator is designated as a master generator that uses a phase-locked loop to automatically lock feedback from the first ultrasonic welding triplet to itself and instructs the second generator, which acts as a slave generator, to match its own phase and frequency feedback to the phase and frequency generated by the first generator.

The part may be constructed of materials including polymeric films, thermoplastic materials, nonwoven materials, metal foils, or metals. The part is a pillow pack having an end with a different number of layers arranged across the longitudinal direction of the end. The part may include a different number of layers including a first number of layers in a first portion of the part and a second number of layers in a second portion of the part along the portion of the part to be sealed, the first number being different than the second number.

The part may be a pillow pack or a carton or stand up pouch. The feature may also be a spout sealed to the pouch.

The first welding head may be a rotating welding head, and the second welding head may also be a rotating welding head. The controller may also be configured to rotate the first and second welding heads at the same rotational speed while simultaneously applying synchronized first and second ultrasonic energy to the part.

The first generator may include an output one operatively connectable to the first transducer and an output two operatively connectable to the second transducer. The first transducer can be operatively connected to the first bonding tool and the second transducer can be operatively connected to the second bonding tool.

The region where the part is far field welded may be at least 1/4 inch or 6 millimeters from the first welding surface of the first welding head or from the second welding surface of the second welding head.

According to another aspect of the present disclosure, a method of ultrasonic welding of multiple layers of a sealing part includes the steps of: moving the first welding surface of the first welding head towards the second welding surface of the second welding head opposite to the first welding surface so as to close a gap between the first welding surface and the second welding surface until the first welding surface and the second welding surface are in contact with a region to be sealed of the part; once contacted with the part, a first path of ultrasonic energy is applied to the part by the horn and a second path of ultrasonic energy is applied to the part by the horn, the frequencies and phases of the two paths of ultrasonic energy being synchronized when applied simultaneously to both sides of the part, sealing the part weld area, with the first and second horns being disposed opposite each other.

The method may further comprise: once the layers are sealed, the first welding head is retracted relative to the second welding head to release the part. The frequency may be between 15kHz and 70 kHz. The movement may also be a rotational movement of the first welding head at the same speed as the second welding head.

The amplitude of the first path of ultrasonic energy may be the same as or different from the amplitude of the second path of ultrasonic energy. Devices having at least one seal applied by the methods disclosed herein are also contemplated.

In accordance with another aspect of the present invention, an ultrasonic welding or metal forming system is disclosed. The system includes synchronized ultrasound transducers and includes: an ultrasonic transducer assembly comprising a horn, a second transducer and a first transducer arranged to transfer ultrasonic energy into the horn, the horn having a first part-engaging surface; a gap configured to receive a part therein to receive ultrasonic energy from the first transducer and the second transducer at a contact surface by the horn; a drive unit operatively couplable to the ultrasound transducer assembly and configured to move the part relative to the gap; one or more controllers operably coupled to the ultrasound transducer assembly and the drive unit, the one or more controllers operably configured to: the method includes causing the drive unit to push the part toward the gap until the part is pressed against the first part contact surface and thereby applying a first path of ultrasonic energy to the part through the horn via the first transducer and a second path of ultrasonic energy to the part through the horn and via the second transducer such that the frequencies and phases of the first path of ultrasonic energy and the second path of ultrasonic energy are synchronized when the first path of ultrasonic energy and the second path of ultrasonic energy are applied to the part.

The first part contact surface of the horn may vibrate back and forth as the first path of ultrasonic energy and the second path of ultrasonic energy are applied to the horn by the first transducer and the second transducer. Vibration of the first part contact surface may cause deformation of the part as the part moves relative to the gap. The deformation may be a change in the metal structure of the part, the part may be composed of metal, or the deformation may be a multi-layer seal of the part.

The bonding tool may have a second part contact surface. The system may also include an anvil having a first surface and a second surface. The one or more controllers may be configured to move the first surface of the anvil and the first part contact surface of the horn toward each other and to move the second surface of the anvil and the second part contact surface toward each other to simultaneously seal the first and second seals when the first and second ultrasonic energy are applied to the horn by the first and second transducers.

The system may further include a blade disposed between the first surface and the second surface relative to the anvil. The one or more controllers may be configured to activate the blade to slit along between the first seal and the second seal at the same time or after the first seal and the second seal are formed.

The first part contact surface and the second part contact surface of the horn may vibrate back and forth when the first path of ultrasonic energy and the second path of ultrasonic energy are applied to the horn by the first transducer and the second transducer. The direction of vibration of the first part contact surface and the second part contact surface may be orthogonal to the direction of movement of the parts. Alternatively, the direction of vibration of the welding head may be transverse to the direction of movement of the part relative to the gap.

The bonding tool may have a second part contact surface that is coplanar or parallel to the first part contact surface. The system may further include an anvil having a first surface and a second surface coplanar or parallel to the first surface of the anvil. The one or more controllers may be configured to move the horn and anvil toward each other to simultaneously produce a first seal and a second seal separated by an inner sealing gap when a first path of ultrasonic energy and a second path of ultrasonic energy are applied to the horn by the first transducer and the second transducer.

The system may further include a knife blade disposed between the first surface and the second surface relative to the anvil, the one or more controllers configured to drive the knife blade to slit the seal gap within the part simultaneously with or after the first seal and the second seal are formed. The bonding tool may be a resonant bonding tool. The part may also be a wire that is pulled through the die using the ultrasound transducer system disclosed herein.

In accordance with yet another embodiment, a method of using a synchronous ultrasonic transducer to vibrate a welding head relative to a part contacting the welding head is disclosed. The method comprises the following steps: accommodating a part in a gap defined at least in part by a horn of an ultrasonic transducer assembly, the ultrasonic transducer assembly comprising a horn, a first transducer, and a second transducer, the two transducers being configured to transfer ultrasonic energy into the horn, the horn having a first part engaging surface; pushing the part toward the gap by a drive unit operatively coupled to the ultrasonic transducer assembly until the part contacts the first part engagement surface; when the part contacts the first part engagement surface, a first ultrasonic energy is applied to the part by the first transducer via the horn, while a second ultrasonic energy is applied to the part by the second transducer via the horn, the two energy being synchronized in frequency and phase when applied to the part.

The first part-engaging surface of the horn may vibrate back and forth as the first path of ultrasonic energy and the second path of ultrasonic energy are applied to the horn by the first transducer and the second transducer. Vibration of the first part engagement surface may cause the part to deform as the part moves relative to the gap.

The deformation is a change in the metal structure of the part. The part may be composed of metal. The deformation may seal multiple layers of the part.

The bonding tool may have a second part contact surface. The method may further comprise: the first surface of the anvil and the first part contact surface of the horn are moved toward each other while the second surface of the anvil and the second part contact surface are moved toward each other such that the first path of ultrasonic energy and the second path of ultrasonic energy are simultaneously applied to the horn by the first transducer and the second transducer to seal the first seal and the second seal.

The method may further include driving a blade of the unit that is mounted between the first surface and the second surface of the anvil to complete the slit between the first seal and the second seal when the first seal and the second seal are formed simultaneously.

The method may further comprise: when the first path of ultrasonic energy and the second path of ultrasonic energy are transferred into the welding head by the first transducer and the second transducer, the welding head and the anvil are moved toward each other to simultaneously produce a first seal and a second seal separated by an inner sealing gap, the welding head having a surface coplanar or parallel to a first part contact surface.

The method may further include driving a blade to cut the part at the inner seal gap while simultaneously sealing the first seal and the second seal, the blade being disposed between the first surface and the second surface of the anvil relative to the anvil.

The welding head may include a cutting blade. The first part contact surface may be a cutting edge. The cutting blade may be configured to vibrate back and forth as the first path of ultrasonic energy and the second path of ultrasonic energy are applied to the cutting blade by the first transducer and the second transducer. The height of the cutting blade may be less than the thickness of the part through which the cutting blade cuts.

In accordance with yet another aspect of the present disclosure, an ultrasonic welding system having an ultrasonic transducer assembly is disclosed. The system comprises: an ultrasonic transducer assembly comprising a horn and a first transducer, the first transducer delivering ultrasonic energy to the horn, the horn having a first part contact surface at an exposed edge extending along the length of the horn and being configured to contact a part to be welded, the other, opposite, exposed edge being a second part contact surface, wherein the height is the distance between the two edges or contact surfaces. The horn has a height that is an integer multiple of a wavelength λ of the applied ultrasonic energy and includes at least two nodes and at least two anti-nodes. The at least two nodes are regions or locations of minimum amplitude of ultrasonic energy with the horn and maximum mechanical strain of the horn. The at least two anti-nodes are regions or locations of the bonding tool having a maximum amplitude and a minimum mechanical strain. A first node of the at least two nodes is disposed about λ/4 from the first part contact surface and a second node of the at least two nodes is disposed about λ/4 from the second contact surface. A first anti-node of the at least two anti-nodes is proximate the first part contact surface and a second anti-node of the at least two anti-nodes is proximate the second contact surface. The system further comprises: one or more controllers operatively coupled to the ultrasound transducer assembly and the drive unit, the one or more controllers operatively configured to: the first transducer is caused to directly or indirectly transmit ultrasonic energy into the horn through one or more amplitude modulators to vibrate the first part-engaging surface back and forth along the length in a direction transverse to the height.

The system may also include a second transducer, which may be tuned to have the same or different frequency and amplitude as the ultrasonic energy applied by transducer one. The integer may be one or two or three, and the frequency of the ultrasonic energy may be about 20kHz. Parts sealed according to any of the systems disclosed herein may be formed of a single layer, a bio-plastic, a biodegradable or recyclable layer or material.

According to some embodiments of the present disclosure, a system includes a first horn, a first ultrasonic transducer, a second horn, a second ultrasonic transducer, a memory, and a controller. The first welding head is provided with a first part contact surface. The ultrasonic transducer one is configured to apply ultrasonic energy to the horn one. The second welding head is provided with a second part contact surface. The welding head is positioned relative to the welding head such that the part to be welded is positionable between the first part contact surface and the second part contact surface. The second ultrasonic transducer is configured to apply ultrasonic energy to the second welding head. The memory stores machine readable instructions. The controller includes one or more processors configured to execute machine readable instructions to cause a first path of ultrasonic energy to be applied by the transducer via the horn to vibrate the first part contact surface back and forth along its length. The controller is also configured to move the welding head in a first direction relative to the part to be welded at a first time. The controller is further configured to cause a second path of ultrasonic energy to be applied through the second horn by the second transducer to vibrate the second part contact surface back and forth along its length. The controller is further configured to move the second welding head in a second direction relative to the part to be welded at the first time.

In some embodiments of the system, the first part contact surface of the first welding head includes a part first curved contact portion and a part second curved contact portion, the part first curved contact portion and the part second curved contact portion configured to assist the first part contact surface in engaging the part to be welded.

In some embodiments of the system, the first part contact surface of the first weld head includes a first part contact portion having a first angle and a second part contact portion having a second angle, the first part contact portion and the second part contact portion being configured to assist the first part contact surface in completing a weld of the part. The first angle and the second angle may be between about 1 degree and about 5 degrees.

In some embodiments of the system, the first direction is different from the second direction. For example, the first direction may be opposite the second direction. The control system may be further configured to: moving the welding head in a second direction at a second time after the first time; and moving the second welding head along the first direction at the second time.

In some embodiments of the system, the first direction is the same as the second direction. The control system may also be configured to move the first and second heads in a third direction at a second time subsequent to the first time.

In some embodiments of the system, the controller is configured to cause the first path of ultrasonic energy to have a first frequency and a first phase and the second path of ultrasonic energy to have a second frequency and a second phase. In some embodiments, the first frequency may be the same as the second frequency and the first phase may be the same as the second phase. Alternatively, the first frequency may be the same as the second frequency, and the first phase may be different from the second phase.

In some embodiments, the first frequency is different from the second frequency and the first phase is different from the second phase. The first frequency and the second frequency may be about 20kHz and the first path of ultrasonic energy has a first phase and the second path of ultrasonic energy has a second phase that does not match the first phase. The first frequency may be about 20kHz and the second frequency may be about 35kHz, the first path of ultrasonic energy having a first phase and the second path of ultrasonic energy having a second phase that does not match the first phase.

In some embodiments of the system, the system further comprises: a first amplitude modulator located between the first horn and the first ultrasonic transducer; and a second adjuster positioned between the second welding head and the second ultrasonic transducer. The system may further include: an ultrasonic transducer III configured to apply ultrasonic energy to the first weld head; and a fourth ultrasonic transducer configured to apply ultrasonic energy to the second horn. The system may further include: a third amplitude modulator positioned between the first welding head and the third ultrasonic transducer; and a fourth amplitude modulator positioned between the second welding head and the fourth ultrasonic transducer.

In some embodiments of the system, the system further comprises an ultrasonic transducer three configured to apply ultrasonic energy to the first horn; and an ultrasonic transducer IV configured to apply ultrasonic energy to the second horn.

In some embodiments of the system, the first horn includes a plurality of grooves along a major surface thereof, and wherein the second horn also has a plurality of grooves machined along a major surface of the second horn, at least some of the grooves having a length in a transverse direction perpendicular to the length to facilitate vibration of the first and second horns.

In some embodiments of the system, the first horn includes a third part contact surface opposite the first part contact surface, the second horn includes a fourth part contact surface opposite the second part contact surface, wherein the first path of ultrasonic energy vibrates the third part contact surface back and forth along its length, the second path of ultrasonic energy vibrates the fourth part contact surface back and forth along its length, and wherein the controller is further configured to rotate the first horn about its longitudinal axis and rotate the second horn about its longitudinal axis such that the part to be welded passes between the first part contact surface and the second part contact surface or between the third part contact surface and the fourth part contact surface.

In some embodiments of the system, the controller is further configured to rotate the first and second welding heads while applying a first path of ultrasonic energy to the first welding head and a second path of ultrasonic energy to the second welding head.

In some embodiments of the present disclosure, a method comprises: the transducer ultrasonically energizes horn one Shi Jialu causing the first part contact surface of horn one to vibrate back and forth along its length. The method further comprises the steps of: the transducer applies a second path of ultrasonic energy to the second horn to cause the second part contact surface of the second horn to vibrate back and forth along its length. The method further includes moving the part to be welded between a first part contact surface of the first weld head and a second part contact surface of the second weld head. The method also includes moving the first welding head in a first direction relative to the part to be welded at a first time. The method further includes moving the second welding head in a second direction relative to the part to be welded at the first time.

In some embodiments of the method, the first direction is opposite the second direction. The method may further include moving the first welding head in a second direction at a second time subsequent to the first time, and moving the second welding head in the first direction at the second time.

In some embodiments of the method, the first direction is the same as the second direction.

In some embodiments of the method, the first path of ultrasonic energy has a first frequency and a first phase and the second path of ultrasonic energy has a second frequency and a second phase. In some examples, the first frequency is the same as the second frequency, and the first phase is the same as the second phase. In other examples, the first frequency is different from the second frequency. In a different example, the first frequency is about 20kHz and the second frequency is about 35kHz.

The above summary is not intended to represent each embodiment, or every aspect, of the present disclosure. Other features and benefits of the present disclosure will be apparent from the detailed description and drawings set forth below.

Drawings

FIG. 1 is a schematic view of an ultrasonic welding system for multi-layer sealing of parts.

Fig. 2 shows a pillow pack with an end gas tight seal made up of different layers.

Figure 3A illustrates a multi-layer folded structure requiring seal welding for the roof seal of various configurations of carton packages.

Fig. 3B illustrates the sealing feature of the roof top, showing the presence of different layers along the width, height and depth dimensions of the gable top.

Fig. 4A illustrates a dual horn ultrasonic welding triple case, with the dual horns disposed directly opposite each other to define a gap between which the part is inserted and the layers are sealed welded together.

Fig. 4B illustrates the ultrasonic welding triplet of fig. 4A wherein the welding heads are closed together. For ease of illustration, the parts to be sealed have been removed from between the bonding tools.

Fig. 5A illustrates a dual triad apparatus configured to perform a "scratch" welding action with synchronized ultrasonic energy applied to a respective welding head of each triad.

Fig. 5B is a cross-sectional view illustrating a method of sealing a weld by side scraping an intermediate part with two welding heads to which synchronized energy is applied.

Fig. 5C illustrates an example configuration of simultaneous ultrasonic energy applied simultaneously to opposing bond heads to weld in a scratch fashion.

The same configuration and application shown in fig. 5D and 5C is shown with the two welding heads separated so that the welded or sealed part can be placed.

Fig. 6A illustrates an example of a dual horn mechanism mounted in opposition that applies simultaneous ultrasonic energy to both horns to seal weld a nozzle or non-planar structure to a part.

Fig. 6B is a top perspective view of the top welding surface of one of the bottom welding heads, showing a pattern of grooves corresponding to the jets or non-planar structures to be joined using simultaneous ultrasonic energy applied to the dual-phase welding head.

Fig. 6C is a front view of the two welding heads shown in fig. 6A, illustrating the two welding heads being positioned adjacent one another with a part such as a spout interposed therebetween under pressure.

Fig. 7 is an example waveform of ultrasonic energy applied to a first welding head and a second welding head, the waveforms being synchronized in frequency and phase in accordance with aspects of the present disclosure.

Fig. 8A is a front view of a dual rotary horn configuration with synchronized application of frequency, phase and angular velocity to weld or seal parts such as nonwoven fabrics of a multi-layer structure.

Fig. 8B is a rear view of the dual rotary horn configuration shown in fig. 8A.

Fig. 9A illustrates an ultrasonic-assisted metal wiredrawing process using multiple simultaneous ultrasonic transducers.

Fig. 9B illustrates an ultrasonic-assisted metal deep drawing process using multiple simultaneous ultrasonic transducers.

Fig. 9C illustrates an ultrasound-assisted metal extrusion process using multiple simultaneous ultrasonic transducers.

Fig. 9D illustrates an ultrasonic assisted metal forging process using multiple simultaneous ultrasonic transducers.

Fig. 9E illustrates an ultrasonic-assisted metal rolling process using multiple synchronous ultrasonic transducers.

Fig. 10 illustrates a VFFS and HFFS filling, seam and seal welding process, which may be implemented with any of the ultrasonic welding systems disclosed herein.

FIG. 11A is a perspective view of an ultrasonically assisted dicing die-cut one-piece unit assembly with dual ultrasonic transducers that apply synchronized ultrasonic energy to a bonding tool using a "scraping" motion to seal one or more interfaces on a part. Alternatively, the horn assembly may be implemented with a single transducer and two modulators or a single transducer and one modulator that provides cantilever support.

Fig. 11B is a side view of the ultrasonic-assisted cutting and sealing assembly shown in fig. 11A.

FIG. 11C is a perspective view of the ultrasonic-assisted cutting and sealing assembly of FIG. 11A with a part disposed between the horn and anvil.

FIG. 11D is a perspective view of the ultrasonic-assisted cutting and sealing assembly of FIG. 11C, wherein the part is pressed between the horn and anvil to simultaneously form two sealing interfaces on the part.

Fig. 11E is a side view of the ultrasonic-assisted cutting and sealing assembly shown in fig. 11D.

FIG. 11F is an enlarged side view of the ultrasonic-assisted seal cutting assembly of FIG. 11E illustrating two sealing interfaces between the horn and anvil with a blade in the anvil cutting the seal intermediate to separate the seal member from the roll front end.

Fig. 12 is a graphical representation of a Finite Element Analysis (FEA) of an ultrasonic welding triplet used in fig. 11A-11F, with a horn mounted between dual transducers that load ultrasonic energy onto the horn. Another approach is to operate with a single transducer and two modulators or a single transducer and one modulator that provides cantilever support.

FIG. 13A is a perspective view of an ultrasonically assisted cutting and sealing assembly having dual ultrasonic transducers applying synchronized ultrasonic energy to a resonant horn positioned to press a web having multiple layers between the horn and anvil.

FIG. 13B is a perspective cross-sectional view of the ultrasonically assisted cutting and sealing assembly of FIG. 13A, illustrating the blade between the horn and an anvil having a corresponding opening or slot to receive the blade therein, the inter-part connection area being cut as the drive moves it toward the horn.

Fig. 13C illustrates two graphs of FEA analysis of the horn shown in fig. 13A and 13B to show exaggerated deformation or direction of movement of the horn as different phases of ultrasonic energy are transferred from opposite sides of the horn into the horn from the dual transducers.

Fig. 14A is a perspective view of an ultrasonically assisted cutting and sealing assembly with dual ultrasonic transducers applying synchronized ultrasonic energy to a resonant horn that fixedly sandwiches a multi-layer roll between the horn and anvil. Another solution is to use a single transducer and two modulators or a single transducer and one modulator that provides cantilever support.

Fig. 14B illustrates two graphs of the FEA analysis of the horn shown in fig. 14A to show exaggerated deformation or direction of movement of the horn as different phases of ultrasonic energy are transferred into the horn from opposite sides of the horn from the dual transducers.

Fig. 15A is a top or bottom view of a cutting blade sandwiched between two ultrasonic welding triplets, the transducers of the ultrasonic welding triplets outputting synchronized ultrasonic energy into the cutting blade.

Fig. 15B is a side view of the cutting blade and ultrasonic welding triplet shown in fig. 15A.

Fig. 16A is a perspective view of a rotatable resonant cutting blade sandwiched between two ultrasonic welding triplets, the transducers of the ultrasonic welding triplets outputting synchronized ultrasonic energy into the cutting blade, the cutting blade acting like a resonant horn. Alternatively, the horn device may be driven by a single transducer.

Fig. 16B is a side view of the cutting blade assembly shown in fig. 16A.

Fig. 16C is an end view of the cutting blade assembly shown in fig. 16A.

Fig. 17A is a perspective view of the rotatable cutting blade assembly shown in fig. 16A cutting through thick blocks such as food.

Fig. 17B is an end view of the rotatable cutting blade assembly shown in fig. 17A, with a double ultrasonically welded triplet visible.

Fig. 17C is a side view of the rotatable cutting blade assembly shown in fig. 17A.

Fig. 18A is a functional illustration of a cutting blade configured to cut through a substance having a thickness T1 from the top or bottom of the cutting blade surface.

Fig. 18B is a functional illustration of a cutting blade configured to cut through a substance having a thickness T2> > T1 and also greater than the height of the cutting blade.

Fig. 18C is a functional illustration of a cutting blade showing how the cutting blade can be rotated to cut a mass at least twice per complete rotation of the cutting blade.

Fig. 19A illustrates a paddle-like wiping metal welding horn having an elongated groove and a scaly projection along the wiping surface of the horn.

Fig. 19B illustrates another paddle-like wiper metal welding horn having an elongated slot and a single squamous tab along each edge of the horn.

Fig. 19C shows a graphical representation of FEA analysis of the bonding tool shown in fig. 19B.

Fig. 20A, 20B and 20C are exaggerated FEA analysis illustrations with corresponding bonding tools having different lengths and different numbers of slots.

FIG. 21 is an illustration of a cross-seal paddle horn with keyhole-shaped slot to facilitate scraping movement along its laterally exposed edge surface.

Fig. 22 is a FEA analysis of a prior art conventional bonding tool in which the back and forth motion of the bonding tool is elongated along the height of the bonding tool rather than along the width of the bonding tool.

Fig. 23 is a FEA analysis of a prior art conventional metal welding horn oriented horizontally, full-length, to produce an undulating motion pattern along its length that is not suitable for a wiping action along its entire length, but is shown in yellow at only a small portion of its surface.

Fig. 24 is a FEA analysis of a paddle horn according to the present disclosure, showing the design principle of the arrangement of nodes and anti-nodes to produce a wiping motion along the width of the horn (perpendicular to its height).

Fig. 25 is a perspective view of an ultrasonic welding system according to some embodiments of the present disclosure.

Fig. 26A is a perspective view of a horn of the ultrasonic welding system of fig. 25, in accordance with some embodiments of the present disclosure.

Fig. 26B is an end view of the bonding tool of fig. 26A according to some embodiments of the invention.

Fig. 27 is a top view of a first welding head and a second welding head of the ultrasonic welding system of fig. 25, in accordance with some embodiments of the present disclosure.

Fig. 28 is a process flow diagram of a method of ultrasonically welding parts in accordance with some embodiments of the invention.

Fig. 29 is a FEA analysis applied to a bonding tool of the present invention illustrating the design principles of the node and anti-node arrangement.

While the disclosure is susceptible to various modifications and alternative forms, specific implementations and embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the disclosure is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Detailed Description

The surprising result found by the inventors disclosed herein is that a very good seal (gas and liquid tight) can be formed using a double horn that transmits energy at ultrasonic frequencies when the frequencies and phases of the double horn are synchronized. As used herein, phase is synchronized when two waveforms agree at 0 degrees ("push-push") or 180 degrees ("push-pull"). Any other angle is considered asynchronous. This has the advantage that only one pass is required to form a sealed seal, and that the seal can be formed by a single application of ultrasonic energy (e.g., 0.35 seconds) in as little as one second or less. The seal does not leak and works particularly well when the interface to be sealed has a complex number of layers to be sealed together. For example, at the seal of a milk house top box top, the sealing area is a two-layer structure, another partial area is up to four layers, and the partial area may also be five layers, depending on how the carton panels are folded, the sealing problem becomes particularly challenging when sealing across different layers of thickness, where different layers are present in different locations along the area of the interface to be sealed.

Examples of these complex interfaces to be sealed can be seen in fig. 2-3 and 6C.

Ultrasonic transducers are devices that convert energy into sound, typically in the nature of ultrasonic vibrations-sound waves having frequencies above the normal range of human hearing. One of the most common types of ultrasonic transducers in modern use is a piezoelectric ultrasonic transducer, which converts an electrical signal into mechanical vibrations. Piezoelectric materials are materials that generate a voltage in response to the application of mechanical stress, and are traditionally crystalline structures and ceramics. Since this effect applies equally inversely, the voltage applied to the piezoelectric material of the sample will create mechanical stress in the sample. Accordingly, properly designed structures made from these materials may bend, expand or contract when an electrical current is applied thereto.

Many ultrasonic transducers are tuned structures that include piezoelectric ("piezoelectric") ceramic rings. Piezoceramic rings are typically made of a material such as lead zirconium titanate ceramic (more commonly referred to as "PZT") that has a proportional relationship between the voltage it applies and the mechanical strain (e.g., thickness) of the ring. The electrical signal provided is typically provided at a frequency that matches the resonant frequency of the ultrasound transducer. In response to the electrical signal, the piezoceramic rings expand and contract to produce vibrations of large amplitude. For example, a 20kHz ultrasonic transducer typically produces a 20 micron vibration peak-to-peak (p-p) amplitude. The electrical signal is typically provided as a sine wave by a power supply that conditions the signal to produce consistent amplitude mechanical vibrations and to protect the mechanical structure from excessive strain or sudden changes in amplitude or frequency.

Typically, the ultrasonic transducer is connected to an optional ultrasonic amplitude modulator and ultrasonic horn (also commonly referred to as a "weld mode" in the ultrasonic welding industry), both of which are typically tuned to have a resonant frequency that matches the resonant frequency of the ultrasonic transducer. The optional ultrasonic amplitude modulator configured to allow mounting of an ultrasonic transducer assembly (or "triad" as it is commonly referred to) is a tuned half-wave component configured to increase or decrease the amplitude of vibration passing between the transducer and the ultrasonic horn. The amount of increase or decrease in amplitude is referred to as the "gain". The horn structure, typically a tapered metal bar, is configured to increase the amplitude of the oscillating displacement provided by the ultrasonic transducer, thereby increasing or decreasing the ultrasonic vibrations and distributing the ultrasonic vibrations over a desired working area.

In general, all mechanical parts used in an ultrasound transducer assembly must be configured so as to operate at a single resonant frequency near or at the desired operating frequency. In addition, the ultrasound transducer assembly must often operate with vibratory motion parallel to the main axis (i.e., the central longitudinal axis) of the assembly. The power supply for the triplet typically operates as part of a closed loop feedback system that monitors and regulates the applied voltage and frequency.

For certain applications, particularly those involving welding thermoplastic parts together, ultrasonic welding techniques are popular for their consistency (particularly when the motion of the triad is controlled by a servo drive motor), speed, weld quality, and other advantages. The inventors have found that by matching the phase and frequency of the energy delivered by the two welding heads and applying the energy on either side of the complex interface, the simultaneous application of ultrasonic energy to a complex interface having multiple layers across the area to be sealed using a dual welding head surprisingly results in excellent air tightness and sealing in one pass. The power to each welding head is controlled by an ultrasonic generator that delivers consistent and reliable energy to the welding head even in noisy environments. Examples of such ultrasonic generators suitable for use in conjunction with the systems and methods described herein are disclosed in U.S. patent No. 7,475,801, which is incorporated by reference herein in its entirety, and suitable ultrasonic generators may be identified as brand iQ ^TM Commercially available from Dukane. Each welding head can be manufactured by iQ ^TM An ultrasonic generator or similar generator is driven to output a consistent and reliable ultrasonic energy signal through a welding head to one or more parts to be welded or joined. Because of the ultrasonic generator The components and structures are well known to those familiar with ultrasonic welding, so a detailed description thereof has been omitted for brevity, as such detailed description is not necessary to understand the invention disclosed herein. Each welding head (or technically the transducer of the welding head) may be powered by a separate power source, or may be powered by a single power source having independently controllable dual power outputs. The overall process or cycle time from the application of force to the horn 106, 108 to the removal of ultrasonic energy may be very fast, such as 0.35 seconds or even faster if higher amplitude energy is used.

The force applied to the part to be sealed can be adjusted within a reasonable range, such as +/-50% from the nominal value for each size machine or part. The geometry, materials, and desires of the parts of the final product define the choice of operating frequencies (e.g., as a general rule, lower frequencies and higher amplitudes for larger parts, higher frequencies and lower amplitudes for smaller parts). In ultrasonic welding, three parameters basically need to be adjusted to obtain a high quality and consistent weld for a particular part: a) Amplitude of vibration; b) Force; and c) welding time (time for applying ultrasonic energy to the part). Most applications require short welding times to maximize yield, particularly in packaging applications where hundreds or thousands of packages are filled and sealed per hour. The amplitude is typically limited by the stress in the horn, and thus there are practical limits on how high the amplitude can be set. This leaves a force, but an increase in force can quickly achieve a good weld, too much force can limit the motion of the ultrasound triplet and can damage or destroy the ultrasound triplet. Alternatively, the triplet may be stuck, just like a brick wall would be closed by the mouth of a white shark. If the brick wall does not yield, the motion of the triplet will be difficult to maintain. The roof pack top requires more force, while the pillow pack requires less force applied by the welding head. The film will require different amplitude and force ratios, which may also be based on material and speed requirements. The systems and methods disclosed herein allow for greater flexibility, as well as significantly expanding the process window, which means that the process is less sensitive to production variables and more flexible than conventional methods.

FIG. 1 is an ultrasonic welding system 100 for sealing together multiple layers of a part 110. The system 100 includes two ultrasonic welding triplets (as shown in fig. 4A and 4B) that include a first transducer 102 and a second transducer 104. The system 100 includes a first welding head 106, the first welding head 106 having a first welding surface 106a opposite a second welding surface 108a of a second welding head 108, thereby defining a gap 112 between the first welding surface 106a and the second welding surface 108 a. The gap 112 is configured to receive a part 110 therein having a different number of layers that will seal along portions of the part 110. For ease of illustration, the portion of the part 110 to be sealed is illustrated in exaggerated enlarged and slightly expanded form in fig. 1, thereby illustrating from left to right that there are different numbers of layers in the case part 110. In practice, these layers will press against each other when they are placed in the gap 112. Starting from the left side of fig. 1, as shown in dashed lines, the first portion of the part 110 to be sealed has four layers, followed by a second portion having only two layers, followed by a third portion having four layers, and finally a fourth portion having five layers. This type of interface is typically found in roof box packages having a top box as shown in fig. 3A. Fig. 3A shows an exemplary carton in a fully assembled configuration, a folded-in-half, and a fully unfolded flat starting configuration. In the latter configuration, the complexity of the folds and layers can be seen at the top of the flat carton, with five sections 340a to 340f. When folded to form roof 334, the five portions create an interface with multiple layers as shown in fig. 1. The area of the bonding tool 106, 108 that is in contact with the part to be sealed is referred to herein as the "bonding surface," which means the bonding surface is the contact surface of the bonding tool that is in contact with the part via which ultrasonic energy is transferred into the interface of the part to be sealed to bond (or seal) the interface. Ultrasonic energy exits the welding surface through the welding heads and enters the parts in contact with the welding surface of the respective welding heads. Each welding surface 106a, 108a of the welding heads 106, 108 is in physical contact with a different area of the part to be welded (the sealing interface of the part), for example, in the case of a roof covering, on either side of a roof formed when all layers are sealed together.

The interface to be sealed may have not only a different number of layers across its width, but also a different number of layers across its height, as shown in fig. 3B. Here, as shown in the illustration, at least five portions 350, a, b, c, d, e need to be sealed together to form a hermetic seal. For example, along the long width dimension of the interface 110, 310 shown in fig. 3B, there are four sections, starting from left to right, with four layers 350B, then two layers 350c, then four layers 350d, ending with five layers 350 e. However, above these portions along the height dimension, there is an elongated portion 350a having only two layers. Thus, taken along the height dimension (the height dimension being transverse to the longitudinal direction of the roof 310), there is only one portion in the middle of the interface 310, where there are two layers in the area to be sealed. Anywhere else, there are different numbers of layers above and below the respective portions of the interface 310 to be sealed. Roof sections 334 of this type are particularly difficult to seal because of the multi-dimensional variation in the number of layers (due to the variation in thickness of the different layers) across their width, height and depth. Conventional adhesive-free methods are time consuming and require multiple welds along the interface, otherwise they fail to produce an airtight seal that prevents leakage of liquid. Carton 330 may also sometimes include a spout 332 protruding from the roof to facilitate pouring. The roof box 334 can be opened from the top like a milk box to pour out the filled liquid. The invention is particularly suitable for sealing roof boxes tops having many different layers in all three dimensions.

Another type of component with a similar seal is a pillow pack 230, as shown in fig. 2, having a top or end similar to a roof pack. Pillow packs are typically first welded at a first seam extending longitudinally of the pack, which seam exhibits a multi-layered structure. The end 210 of the pillow pack 230 also has multiple layers, as shown in the illustration. In this configuration, sometimes referred to as 4-2-4-2-4, there are four layers in the first portion of the end 230, followed by two layers, followed by four layers, followed by two layers, and finally four layers. Thus, a different number of layers are arranged in the longitudinal direction of the end 210 of the pillow package 230. Again, this type of part with different layers presents special challenges for sealing. The synchronized double horn/triple stack of the present disclosure is configured to seal the pillow package such that h makes the pillow package airtight without any leakage. The pillow pack shown in fig. 2 and the carton 330 shown in fig. 3A may be made of a polymer film or a thermoplastic material.

The invention disclosed herein may be applied to seal another type of part that is a fluid filled bag having a valve or pierceable sealing element that can be pierced, such as by a straw, as described in U.S. patent application publication No. 20040161171 A1. An exemplary system configured to seal a fluid-filled pouch using the ultrasonic techniques disclosed herein is illustrated and described in connection with fig. 5A-5D. Under the trademark of America Popular soft bags are sold. An example system configured to seal a part having a spout using the ultrasonic techniques disclosed herein is illustrated and described in connection with fig. 6A-6C.

In a liquid filled pouch, when liquid is already present in the pouch prior to sealing the pouch, the synchronized ultrasonic energy from the double horn creates vibrations at the interface that expel the liquid from the interface area, further contributing to the creation of a hermetic seal. In other words, the surprising benefit of applying dual synchronized ultrasonic energy to a liquid filled part is that the vibration created by applying energy from both sides of the interface to be sealed tends to vibrate away any liquid droplets present around the interface, allowing the layers of the interface to seal together without trapping liquid therebetween and causing a risk of leakage. Microscopic leaks also present a health and sporadic hazard, allowing bacteria or other pathogens to enter the sealed bag or mold to form around the seal. Additional advantages can be seen in the simultaneous dual horn configuration disclosed herein by forming an airtight seal in one pass of the dual horn, wherein liquid is released by vibration generated by the application of ultrasonic energy from both sides of the opening of the liquid filled bag at the interface prior to sealing.

Returning to fig. 1, the system includes a driver assembly 116, the driver assembly 116 being operatively coupled to an ultrasonic welding triplet (fig. 4A and 4B) and configured to move a first welding surface 106a of a first welding head 106 relative to a second welding surface 108a of a second welding head 108. The movement of the bonding tools 106, 108 together may be aided by respective frames 130, 132, with the respective bonding tools 106, 108 coupled to the frames 130, 132, the frames 130, 132 forming part of a driver assembly that moves the bonding tools 106, 108 toward or away from each other. One movement that causes the bonding tools 106, 108 to collectively clamp the part to be sealed and then separate after ultrasonic energy is applied to the part is referred to as a single pass or cycle. The driver assembly 116 may include one or more motors, such as servo motors. The two welding surfaces 106a, 108a are directly opposite each other and form mutually parallel planes perpendicular to the direction of the welding heads 106, 108. The two welding heads 106, 108 are movable toward each other, like a jaw that opens and closes such that their exposed end welding surfaces 106a, 108a contact respective opposing surfaces of the part or part interface to be sealed. The respective ultrasonic energy transmitted from the transducers 102, 104 to the welding heads 106, 108, synchronized in frequency and phase, is output in opposite directions along the same dimension. Each of the dual ultrasonic welding triplets may include an optional amplitude modulator 140, 142, as shown in fig. 4A, that amplifies the energy emitted from the transducers 102, 104 before the energy enters the welding heads 106, 108. Also, the presence of enhancers 140, 142 is optional, and the configuration shown in fig. 5A and 6A lacks an amplitude modulator. In these configurations, the transducers 102, 104 are mounted directly to the bonding tools 506, 508 (fig. 5A) and the bonding tools 606, 608 (fig. 6A).

The controller 120 may be configured with one or more that are operatively coupled to the ultrasonic welding triplet and driver assembly 116. The controller 120 is configured such that the actuator assembly 116 presses the first and second welding surfaces 106a, 108a of the welding heads 106, 108 toward each other until the part 110 is contacted. A predetermined force may be applied to the bonding tools 106, 108, generally clamping the part 110 between the bonding surfaces 106a, 108b and holding the folded layers together. For example, the maximum force exerted by the welding head on part 110 may be set at 4500N, but the force is dependent on the thickness of the interface materialAnd the nature of the material itself. The controller 120 applies a first path of ultrasonic energy to the part 110 through the output of the first horn 106 and applies a second path of ultrasonic energy to the part 110 through the output of the second horn 108 such that when the first and second paths of ultrasonic energy are applied to both sides of the part 110 simultaneously, the frequencies and phases of the first and second paths of ultrasonic energy are synchronized to seal the layers together, such as 350a, 350B, 350c, 350d, 350e illustrated in fig. 3B. As mentioned above, an exemplary ultrasonic generator suitable for generating ultrasonic energy into a horn by a transducer is described in U.S. Pat. No. 7,475,801, which can be any iQ from Dukane ^TM Ultrasonic generators of wires are commercially available.

Synchronization of the two ultrasonic generators may be achieved by providing a communication connection between the two generators such that the outputs of the two generators to the transducers 102, 104 are synchronized in frequency and phase. Alternatively, it may be modified to the generator described in the above patent, and two outputs synchronized in frequency and phase may be provided to the respective transducers 102, 104. The generators (whether separate or integrated by dual outputs) may be arranged in a master-slave relationship, with one of the generators designated as the master generator. A Phase Lock Loop (PLL) is used to automatically Lock the Phase of the master generator to the feedback of its ultrasound triplet and the master generator instructs the slave generator via the communication connection to simulate the same Phase at zero crossings (0 or 180 degrees) and ignores the Phase and frequency feedback of the slave generator itself. This allows the slave generator phase to drift in the same way as the master generator. For example, due to thermal effects, phase drift may occur, thus allowing synchronization of the phases (and thus, in a sense, the frequency of zero crossings corresponding to the phase of the ultrasonic energy signal) in the two transducers 102, 104 by locking the phase of the slave generator to the master generator.

Fig. 7 illustrates example waveforms, not to scale, of synchronized ultrasonic energy applied to the first transducer 102 and the second transducer 104. Here, synchronization means that energy has the same frequency f1 and phase. The amplitude a may be the same or different for both welding heads. Depending on the thickness and application of the parts closest to the bonding tools 106, 108, different amplitudes may be applied by the first bonding tool 106 relative to the second bonding tool 108. Just as the frequency f1 is matched in the two welding heads 106, 108, the phases of the two energies are also time synchronized so that the zero crossings and the peak values of the energy over time coincide simultaneously, as shown by the dashed lines in fig. 7. The frequency f1 of the energy generated in one welding head 106 (or transducer 102) may be within 3Hz of the energy generated in the other welding head 108 (or transducer 104). The use of two synchronized horns reduces the energy attenuation through multiple layers by half, such as when sealing a gable top, as compared to a single horn configuration. For example, in a single triplet configuration, ultrasonic energy must pass through the 4-5 layers at the top of the chevron, thereby producing up to about 50% attenuation or loss of ultrasonic energy/amplitude. In contrast, when using a synchronous twin horn according to the present disclosure, the energy from one horn passes through only 2 or 2.5 layers (and similarly the energy from the other side passes through only half the number of layers as compared to a single stack structure), thus the energy/amplitude loss is only about 20-25%, resulting in a high quality weld or seal without scalding the seal layer or generating cosmetic blemishes on the outer surface of the seal.

It has been found that the frequency of the ultrasonic energy transmitted to the horn 106, 108 by the two transducers 102, 104 is between about 15-70kHz (e.g., ±10%). Particularly effective results are seen for 15kHz, 20kHz and 30 kHz. The frequency and phase of the ultrasonic energy transmitted to the welding heads 106, 108 by the two transducers 102, 104 to seal the part is synchronized in time such that the peak amplitude of the ultrasonic energy is transmitted simultaneously to both sides of the part to be sealed. The amplitude of the ultrasonic energy may be independently controlled at the two transducers 102, 104. Frequencies of 20-35kHz are particularly suitable for sealing smaller or thinner packages, while lower frequencies may be used for sealing larger or thicker packages.

A "scraping" configuration case is illustrated in fig. 5A to 5D. In this configuration, there are two transducers 102, 104 synchronized in frequency and phase as in the previous configuration, but the bonding heads 506, 508 are positioned so that their sides contact to press against the interface of the part to be sealed, such as a thin film with a thickness in the range of 10-20 μm or even over 100 μm, or a thin nonwoven film with a thickness that can vary along the length of the interface. The variation in thickness may be + -2 μm at unpredictable locations along the interface length. Thus, while the application of energy may be uniform, the thickness of the interface (e.g., the interface may be composed of only two layers sealed together) may vary along the length of the interface sealed together, creating a small leakage of the seal or a risk of causing uneven welding. When frequency and phase synchronized ultrasonic energy is transferred to the welding heads 506, 508 through the transducers 102, 104, the so-called wiping action balances the small mechanical Y-axis motion created by the vibration of the two welding heads 506, 508 relative to each other. These vibrations create a very short, rapid back and forth motion in the horns 506, 508, similar to a scraping motion, which has been found to produce a very high quality hermetic seal where the interface has a non-uniform thickness, such as when the interface is a thin film or a nonwoven film. The configurations shown in fig. 5A-5D also allow for milder control of the amplitude and force applied to the thin interface and allow for a wider process window.

In fig. 5A, each of the two ultrasonic welding triplets includes a transducer 102, 104 and a horn 506, 508. The welding heads 506, 508 are positioned adjacent to one another such that the respective side welding surfaces 506a, 508a of the welding heads move toward one another. These welding surfaces 506a, 508a are parallel to the Y-Z plane and extend a length along the Z axis. Ultrasonic energy is applied through the transducer 102 in the Y-axis direction and ultrasonic energy is applied through the second transducer 104 in the opposite direction in the Y-axis direction. The side surfaces 506a, 508a vibrate through each other when the part is positioned therebetween and ultrasonic energy synchronized in frequency and phase is simultaneously applied through the bonding tools 506, 508. The film or thin nonwoven forms a hermetic seal by passing ultrasonic energy through the horn 506, 508 only once. Only two welding heads 506, 508 and one channel are required to create a consistent hermetic seal without burn or cosmetic blemish or microscopic leakage. Although films or nonwovens have been described in these examples, the scratch welding methods disclosed herein may also be used to weld metal films, metal foils or thin metals, or films, nonwovens, or welding of metals. For example, scraping is particularly effective when metal seals are welded together, but also when seal welds of dissimilar materials are performed, such as sealing a nonwoven material to a metal film or foil.

In fig. 5B, a close-up of the two side welding surfaces 506a, 508a can be seen from the welding heads 506, 508. 506a has a raised long wheel on the weld side to create a smaller weld contact area than 508 a's flat weld side surface. In this manner, the part 110 is placed between the two welding heads 506, 508, and the side welding surface 506a acts as a "scratch" when rapidly moved back and forth in the Y-axis direction under the influence of ultrasound. An exemplary configuration can be seen in fig. 5C, in which the welding heads 506, 508 are in contact with one another. For example, the open end of the bag-setting component 110 requiring one end seal is positioned between the welding heads 506, 508, which will "scrape" the two-layer seal interface when ultrasonic energy is applied from opposite sides of the interface. The mechanical movement associated with ultrasonic energy generates heat that creates an airtight seal without appearance problems or microscopic leaks. Fig. 5D illustrates the separated bonding tools 506, 508. The part 110 seal is located in the gap between the two side welding surfaces 506a, 508a, which side welding surfaces 506a, 508a are driven toward each other in the X-axis direction until the side welding surfaces 506a, 508a contact the seal side of the part 110. When ultrasonic energy is applied into the welding heads 506, 508 through the transducers 102, 104, a force is applied to the welding heads 506, 508, creating a small mechanical vibration known as a scraping action along the melting point at the 110 seal where the welding surfaces 506a, 508a squeeze. Once the welding heads 506, 508 are retracted, an airtight seal is achieved at the seal 110 of the part, which requires only one cycle or action of the welding heads 506, 508 and one application of synchronized ultrasonic energy.

Another synchronized double horn configuration is illustrated in fig. 6A-6C, which is suitable for sealing parts having complex geometries, such as liquid bags, pillows, or containers with plastic or metal spouts. Here, the two transducers 102, 104 are positioned relative to a second contour welding head 608 and a first contour welding head 606 having an opening 612 (best shown in fig. 6C) to receive a part 332 to be sealed therein. The ends of the welding heads 606, 608 have knurled surfaces 608B (best shown in fig. 6B) to clamp around the part 332 (which may be, for example, a circular spout), which translates into ribbed welding surfaces 608a that receive the circular (or oval) part 332. The other weld head 608 has the same welding surface so that the weld heads press against each other, the part 332 remains in place, and the uniformly applied energy is uniformly distributed around the part to produce a consistent weld. The contour welding heads 606, 608 may be shaped to match the contours of any part geometry, including circular, elliptical, or any irregular geometry.

Another dual horn configuration is illustrated in fig. 8A and 8B. The two welding heads 806, 808 are of the rotary type, and those familiar with ultrasonic welding will understand the rotary welding heads and how to drive them, the details of which are not relevant to an understanding of this configuration. An example of a configuration including a rotary horn and a fixed anvil is shown in U.S. patent No. 10479025 issued on 11, 19, 2019, entitled "Apparatus for fabrication an elastic nonwoven material" which is incorporated herein by reference in its entirety. According to the concepts disclosed herein, two rotating bonding tools 806, 808 are presented as shown in fig. 8A, wherein the two bonding tools 806, 808 contact both sides of a part 810 having two layers of material 840a, 840b (more than two layers are also possible), such as multiple layers of nonwoven material to be joined or sealed together, and the part passes between the two bonding tools 806, 808 when the bonding tools are rotated at the same angular velocity ω1. As disclosed herein, the frequency and phase of the respective ultrasonic energy applied to the bonding tools 806, 808 are synchronized to produce a high quality seal or bond of the layers 840a, 840b of the part 810 in one pass through the bonding tools 806, 808. As the part 810 passes between the bonding tools 806, 808, a force may be applied to the layers 840a, 840b of the part 810 between the bonding tools 806, 808. The physical separation between layers 840a, 840B is exaggerated in fig. 8A and 8B1 for ease of illustration to illustrate how layers 840a, 840B are welded together by dual rotary bonding tools 806, 808 driven by respective transducers 102, 104. Each of the transducers 102, 104 is powered by a respective output of one or more ultrasonic generators as described above, thereby producing ultrasonic energy outputs of both that are synchronized in both frequency and phase. Thus, in this configuration, the angular velocity ω1 of the horn and the frequency and phase of the ultrasonic energy applied to each horn are synchronously matched.

The layers of material 840a, 840b of the part 810 are drawn between two bonding tools 806, 808, and the two bonding tools 806, 808 are loaded with ultrasonic energy having the same frequency and phase while rotating at the same angular velocity. By applying frequency and phase matched ultrasonic energy to both horns 806, 808 simultaneously, the amplitude of the energy is allowed to be reduced compared to a configuration having only one triplet, which expands the process window while also improving throughput (e.g., over 2000 feet/minute).

Also disclosed herein is an ultrasonic welding method for sealing multiple layers of a part together (forming an interface to be sealed). The method includes moving a first welding surface of a first welding head toward a second welding surface of a second welding head to close a gap between the first and second welding surfaces until the first and second welding surfaces contact a part, such as a part having a different number of layers along a portion of the part to be sealed. In response to contacting the part, the method applies a first path of ultrasonic energy output via a first horn and a second path of ultrasonic energy output via a second horn to a portion of the part between the two horns such that the frequencies and phases of the first and second paths of ultrasonic energy are synchronized while applying the first and second paths of ultrasonic energy to both sides of the part, thereby sealing the layers together. The first welding head and the second welding head are provided with protruding energy guide ribs at the top ends, and the protruding energy guide ribs correspond to each other. Importantly, the sealing of the seal is accomplished with only one closure and opening of the welding head, without causing any scalding, appearance problems, or leaving any air or liquid leakage along the interface. In contrast, conventional methods require multiple horn movements (e.g., three or more) to create a seal, are time consuming, and increase the risk of scalding, leaking, or create undesirable appearance issues, particularly in thinner areas of the interface (e.g., when sealing the roof top).

Aspects of the present disclosure may also be applied to so-called far field welding, where the area to be welded is located away from the welding head output or contact surface of the welding head, from where ultrasonic energy is transferred from the solid substrate to an area external to the welding head. In many applications, the location of the weld relative to the weld head contact area may be critical, as ultrasonic energy must pass through the material to reach the desired melted area. Near field and far field welding refer to the distance that ultrasonic energy is transferred from the weld head contact point to the weld interface. For example, a near field may be considered when the distance between the weld output or contact surface of the weld head and the weld interface to be welded is 1/4 inch (6 mm) or less. Conversely, when the distance is greater than 1/4 inch (6 mm), the weld may be considered far field. The welding near field is always the best if possible. This is because far field welding requires higher amplitude, longer welding time, and greater pressure to achieve an effect equivalent to near field welding. In general, far field welding is suggested only for amorphous resins that transmit energy better than semi-crystalline resins. However, with the dual horn configuration disclosed herein, the application of far field welding can be extended because energy can be applied simultaneously from both sides of the interface.

The twin-horn aspects disclosed herein may also be applied to an ultrasonic-assisted metal wiredrawing process or an ultrasonic-assisted metal forming process. Conventional wire drawing or forming processes only contemplate the use of one ultrasonic energy source applied to a hard steel die when drawing a wire or metal through the die. The pulling force is very high and eventually the die becomes dull and needs to be replaced. While the present disclosure contemplates applying multiple ultrasonic energy of synchronized frequency and phase to both sides of the die while pulling the wire or metal through the die by external pulling forces. The energy produces vibrations in the die, causing the die to act as a lubricant, thereby reducing the force required to draw wire through the die. The mold change time is prolonged, thereby improving the yield of the metal wire drawing or metal forming process.

Fig. 9A-9E illustrate an ultrasonic-assisted metal forming process using synchronized ultrasonic energy. For convenience, the "ultrasonic welding system" as used herein includes an ultrasonic-assisted metal forming process such as that shown in fig. 9A-9E. While these processes do not weld parts together in a conventional or conventional sense, they operate using the synchronous frequency principles disclosed herein and are included in the protection of ultrasonic welding systems. Fig. 9A shows an exemplary configuration of a drawing system 900 having a die 902, the die 902 having a plurality of ultrasonic welding triplets (including transducers and bonding heads) 904a, 904b, 904c, 904d, the ultrasonic welding triplets 904a, 904b, 904c, 904d applying ultrasonic energy synchronized in frequency and phase with respective portions of the die 902. In this example, the mold 902 operates as a horn that mechanically oscillates back and forth in a vibratory motion in accordance with the ultrasonic energy transferred into the mold by the transducers 904a, 904b, 904c, 904 d. Wire drawing and metal forming systems are well known in the art and the configuration of wire drawing and metal forming systems is well known to those skilled in the art and will not be reproduced here for ease of discussion. The basic configuration includes a die 902 of some sort, which in the example shown in fig. 1 is shaped such that when a wire of an initial gauge or thickness is pulled through a gap 915 in the die, typically by pulling, the gap 915 of the die 902 has an initial diameter that is greater than a final diameter such that the diameter of the wire 910 is reduced to a desired gauge or thickness when pulled through the die 902 (912). As the wire 910 is pulled through the gap 915 of the mold 902, the wire 910 is pressed against the first part contact surface 915 and the second part contact surface 917 of the mold 902. Here, the idea of the present invention is to apply energy (in this ultrasonic embodiment, non-resonant parts) to the mold 902 using a synchronous (in frequency and in phase) ultrasonic welding triplet, such that the parts of the mold 902 vibrate mechanically, producing a number of benefits over conventional wiredrawing techniques that do not use frequency synchronous ultrasonic energy. An example of a method for applying ultrasonic vibrations to a non-resonant part is disclosed in U.S. patent No. 9,993,843, entitled "Adapter for Ultrasonic Transducer Assembly (adapter for an ultrasonic transducer assembly)", which is incorporated herein by reference in its entirety.

In the assembly 900 shown in fig. 9A, there are four ultrasonic welding triplets 904a, 904b, 904c, 904d comprising transducers, the ultrasonic welding triplets 904a, 904b, 904c, 904d being arranged around the mold to apply energy into the mold 902 at the transducer locations. In practice, these ultrasonic welding triplets (e.g., 904a and 904d, or 904b and 9s04 c) may be deployed in pairs. In other words, while four ultrasonic welding triplets are shown in fig. 9A, a single pair triplets, such as 904a and 904d, are also contemplated. Also, in one embodiment, the energy is completely synchronized in frequency and phase, as shown by the example waveforms in the figure. In other embodiments, it is also possible to synchronize only the frequencies in the four ultrasonic welding stacks 904a, 904b, 904c, 904d, but to configure more than two different phases to be more efficient. While the representative waveforms shown in the figures are shown as having the same frequency and phase as each other, it should be understood that the phase between any transducers may be different or asynchronous. The synchronized energy applied through the die 902 (operating as a non-resonant part) via the transducers 904a, 904b, 904c, 904d causes the die 902 to mechanically vibrate rapidly (at or near the frequency of ultrasonic energy) to correspond to the on-line lubrication as the line is pulled through the gap 915 of the die 902. Less tension is required compared to conventional techniques because the rapidly vibrating "lubricated" die 902 allows the wire 910 to be pulled through the die more quickly and with less force and without the use of liquid or wet lubricants. Such drawing is referred to as dry drawing because no lubricant or liquid is used at the drawing-die interface to facilitate the drawing process. The wire 910 drawn by this method advantageously has a good smooth surface finish with few or no flaws and increases the drawing speed, reduces the drawing force, reduces or avoids the need to use any external lubricant at the wire-die interface. Wire 910 may be made of copper, aluminum, or any other conductive metal or metal alloy, and may be solid or stranded.

Returning to fig. 9A, when viewed from the left to right, the direction of wire stretching is from left to right, wherein the thicker portion of wire 910 stretches through the input portion of gap 915 of die 902 to create the thinner portion of wire 912 to the right of the output portion of die 902. Four ultrasonic welding triplets 904a, 904b, 904c, 904d are positioned around the die 902, the die 902 acting as a mechanically vibrating horn when ultrasonic energy is applied through the die 902 by the transducers. The top mold 904a is positioned adjacent to the top surface of the mold 902 and the bottom mold 904d is positioned adjacent to the bottom surface of the mold 902. The top die 904a and the bottom die 904d are arranged to direct their respective ultrasonic energy toward each other and toward a wire 910 that is pulled through the die 902. These energies are synchronized in frequency and optionally in phase. In addition, two other transducers 904b, 904c are disposed on the end surfaces above and below the output portion of the mold 902. These transducers 904b, 904c direct their respective ultrasonic energy parallel to each other and in a direction opposite to the direction of travel of the wire 910 through the die 902. This creates a coordinated ultrasonic energy situation within the mold 902 that all vibrate at the same frequency, which causes the surface interface between the mold 902 and the wire 910 to mechanically vibrate rapidly and uniformly in multiple directions. Without the synchronization frequency, the vibrations within the mold will be non-uniform, which will result in the wire having undesirable surface defects as it is pulled through the mold and/or experiencing different mechanical stresses or strains or non-uniform deformations along its diameter as it is pulled through the mold, resulting in one side of the wire being pulled out at a different rate than the other side of the wire.

Another ultrasonic-assisted metal forming process 920 is shown in fig. 9B, in which a metal part 930 is deep drawn with the aid of a die 922 and a punch 926. Three ultrasonic transducers 924a, 924b, 924c are disposed on die 922 and punch 926 to facilitate deep drawing operations on part 930. In this example, an ultrasonic triplet 924c is arranged adjacent to the punch 926 and directs ultrasonic energy in the same direction as the punch moves to complete the deep drawing process on the part 930. The other two ultrasonic welding triplets 924a, 924b are arranged to abut opposite surfaces of the die 922 such that the respective energies of the ultrasonic welding triplets 924a, 924b are directed toward each other and toward the part 930 being punched through the die interface. The ultrasonic frequencies of transducers 924a, 924b, 924c are synchronized, and the phases may also be selectively synchronized. Another alternative is that the phase of the ultrasonic energy applied by transducer 924c through ram 926 may be different relative to the synchronous phase of the energy applied by transducers 924a, 924b to the opposite side of die 922. The part 930 is received in a gap 925 of a mold 922. The mold 922 operates in a non-resonant manner with respect to the triplets 924a, 924b, similar to the mold 902 shown in fig. 9A. Mold 922 has a first part contact surface 935 and a second part contact surface 937, with first part contact surface 935 and second part contact surface 937 contacting part 930 as part 930 is subjected to a deep drawing process. The synchronous vibration of the mold 922 causes the part to vibrate back and forth relative to the mold at the first part contact surface 935 and the second part contact surface 937 (and other part contact surfaces in contact with the mold), primarily those surfaces involved in deforming or bending during deep drawing.

An ultrasonic-assisted extrusion metal forming process 940 is illustrated in fig. 9C, wherein as a metal part 950 is extruded through a gap 945 in a die 942, a metal part 950 is subjected to extrusion through the die 942 by a ram 946, the ram 946 exerting an urging force on the metal part 950. Similar to the assembly shown in fig. 9A, four ultrasonic welding triplets 944a, 944b, 944c, 944d are arranged around the output section of the die 942, and the ultrasonic energy outputs of the ultrasonic welding triplets 944a, 944b, 944c, 944d are synchronized in frequency, and optionally in phase. The physical arrangement of the ultrasonically welded triplets 944a, 944b, 944c, 944d in the assembly 940 is similar to the arrangement of triplets 904a, 904b, 904c, 904d shown in fig. 9A. Arrows indicate the direction of the respective ultrasonic energy output from the transducers of triplets 944a, 944b, 944c, 944d, and these ultrasonic energies through mold 942, which causes part 950 to be extruded through mold 942 by the force of impact of ram 946. At least four part contact surfaces 955a, 955b, 957a, 957b of mold 942 are in contact with corresponding surfaces of part 950 as they undergo a metal forming process.

The forge, ultrasonically assisted metal forming process 960 is illustrated in fig. 9D, wherein a metal part 970 is subjected to compressive forces by a mold 962. Four ultrasonic welding triplets 964a, 964b, 964c, 964d including transducers are arranged adjacent the mold 962, and ultrasonic energy of the ultrasonic welding triplets 964a, 964b, 964c, 964d are synchronized in frequency and optionally synchronized in phase. The top transducer 964a is disposed adjacent the top surface of the top of the mold 962 and directs its energy down into the piece 970. The bottom transducer 964c is disposed adjacent the bottom surface of the mold 962 and directs its energy upward into the piece 970 and toward the top transducer 964a. As shown in fig. 9D, a first side transducer 964D is disposed adjacent the left side of the bottom of the mold 962 and directs its energy into the mold 962 from left to right, as shown. The second side transducer 964b is arranged adjacent to the right side of the top of the mold 962 and directs its energy into the mold 962 from right to left and in a direction opposite the first side transducer 964 d. The part 970 is placed in the gap 965 and contacts at least the first part contact surface 975 of the mold 962 and the second part contact surface 977 of the mold 962, the mold again functioning like an ultrasonic non-resonant part/horn when ultrasonic energy is applied to the horn or mold 962. This arrangement produces a consistent and uniform vibration profile at the die part interface, allowing for uniform compression at a faster rate than conventional metal forging processes.

An ultrasonic assisted roll metal forming process 980 is illustrated in fig. 9E, wherein a part 990 is subjected to rolling forces by two rolls 982a, 982b. The piece 990 passes through the gap 985 between the rollers 982a, 982b in the direction of arrow a, thereby reducing its cross-sectional area. The feature 992 contacts a first feature contact surface 995 of the top roller 982a and a second feature contact surface 997 of the bottom roller 982b. The first ultrasonic triplet 984a is configured to abut the top roller 982a and the second ultrasonic triplet 984b is configured to abut the bottom roller 982b. The ultrasound triplets 984a, 984B are positioned to output their respective ultrasound energy in a direction B transverse or perpendicular to the direction of arrow a. This process 980 results in smoother rolling operations without the use of external lubricants and no defects on the surface of the part 990 being pulled through the rolls 982a, 982b.

Fig. 10 illustrates two example configurations of two packaging systems, in which any of the ultrasonic welding systems disclosed herein may be incorporated. As will be readily appreciated by those skilled in the packaging arts, the machine may be oriented such that the package or pouch or bag or other container filled with a substance (food, liquid, powder, etc.) is structured in either a horizontal or vertical direction. A horizontally disposed packaging system is referred to as a horizontal form, fill and seal (HFFS) packaging system, and a vertically disposed packaging system is referred to as a vertical form, fill and seal (VFFS) packaging system. Implementations and embodiments disclosed herein may be oriented horizontally or vertically and are equally applicable to HFFS and VFFS packaging systems. In the left hand diagram of fig. 10, an example VFFS packaging system 1000a is illustrated. In the right figure, an example HFFS packaging system 1000b is shown. It is reiterated that this illustrates a variety of configurations, and that one of ordinary skill in the packaging arts will understand that other configurations are variations of the configuration shown in fig. 10. These examples are for ease of discussion to illustrate that the ultrasonic welding system herein may be introduced into a packaging system to seal and that the finished part may also be cut into individual pieces.

The exemplary VFFS packaging system 1000a includes a film roll 1002, the film roll 1002 being conveyed in a vertical direction through a roller system toward a forming tube 1006, the product 1004 or any other substance filling a pouch or pocket or bag or container formed from film prior to entering a sealing unit 1012, the sealing unit 1012 optionally separating the film roll 1002 from the assembly. Any of the ultrasonic welding systems disclosed herein, particularly but not limited to those discussed in the subsequent figures, may be integrated as a sealing unit 1012 in a VFFS packaging system as shown in fig. 10.

The exemplary HFFS packaging system 1000b includes a roll of film 1020, which roll of film 1020 is fed through a series of rollers 1022 to a forming box 1030 where the film is folded to form pouches or other containers to hold products or substances 1026 fed by a belt conveyor 1024 to the forming box 1030. The product or substance 1026 enters the forming box 1030 and is contained therein in loose form until the seam is sealed at the top into a tubular package 1034. The pouches or packets 1048 to be formed enter an end seal and cut unit 1040 where the side seals of the pouches are sealed and slit to slit the packets or pouches into individual packages 1050 prior to delivery to a discharge conveyor 1042. To seal and slit the two open sides to form a single package, you 1040 repeat the method repeatedly when the package 1048 to be formed requires two passes of the method to fill the advertisement for the fee. For example, assembly 1040 may be rotated and may replace a corresponding portion of any of the ultrasonic welding systems disclosed herein. The ultrasonic welding system herein overcomes many of the drawbacks found in conventional closure and slitting assemblies, including the need for only a single pass, a higher air-tight effect, and improved throughput of the slitting of the package 1050. Additional benefits compared to conventional heat sealing techniques include: reducing machine downtime; without preheating or cooling, the ultrasonic energy can be immediately used for welding; the welding parameters can be changed in real time response; ultrasonic welding is gentle to the product and packaging material, and does not produce visual or other undesirable appearance defects at the sealing interface; no combustion of the package or material at the machine stop position; no film shrinkage; and no thermal effect on the product packaged in the pouch or container. Heat sealing typically leaves an average top of 13mm (1/2 ") wide; however, ultrasonic seals according to the present disclosure may produce seals as narrow as 1-2mm wide. The pouch or container can also be made smaller because a narrower high quality seal allows for less headspace requirements and without excessive oxygen or product (bag) being locked by a wider seal. Thus, smaller package sizes and smaller seal areas can save up to 25% of material.

Fig. 11A shows a perspective view of an ultrasonically assisted "cut and seal" assembly 1100 having dual ultrasonic transducers applying synchronized ultrasonic energy to a horn 1110 (as shown in fig. 12), the horn 1110 capturing a coil 1102 having multiple layers between the horn 1110 and anvils 1114a, 1114 b. In addition, in applications where welding power requirements are not high, the application of such a horn wiping action may also be configured such that the horn 1110 may be driven by a single ultrasonic transducer. This arrangement takes advantage of the "scraping" action described herein, which is particularly effective in sealing two or more films together in the web 1102. 11A, 11B, 11C, 11D, 11E, 11F, and 12, FIGS. 11A, 11B, 11C, 11D, 11E, 11F, and 12 illustrate how the horn 1110, transducers 1112a, 1112B, and anvils 1114a, 1114B cooperate to apply scratches to the web 1102 with ultrasonic energy while simultaneously sealing adjacent seals between two adjacent portions 1104 of the web 1102 in two locations. While also optionally performing a slitting operation to cut the area between the two sealing portions. Also, while these exemplary configurations are shown in a horizontal orientation for an HFFS packaging system, these examples are equally applicable to a VFFS packaging system and may be oriented vertically. Those familiar with film packaging systems will readily understand that orientation is not critical to achieving the novel and inventive concepts herein.

In this example, a plurality of pouches or pockets 1104d, 1104e, 1104f are made from a roll 1102 formed by filling or pouring (e.g., liquid, food, powder, etc.) between two films 1104a, 1104b or other materials, and then forming and sealing. So-called pillow pouches or bags are well known in the packaging industry and are conventionally formed along continuous rolls, conventionally using heat sealing, followed by slitting into individual packages. Only the structures and devices directly related to the practice and implementation of the claimed invention are described herein, and those skilled in the packaging arts, particularly those of skill in the pillow pouch packaging arts, will be familiar with the machines for filling, sealing and slitting packets.

The present disclosure improves the technology of pillow pouch packaging by incorporating at least two ultrasonic transducers 1112a, 1112b that apply frequency and phase synchronized ultrasonic energy to the horn 1110. An example of such a configuration can be seen in fig. 11A. The transducers 1112a, 1112b are mounted relative to the horn 1110 such that the transducers load respective ultrasonic energy onto the horn toward each other in a direction transverse to the direction of travel of the web 1102 (e.g., from left to right as indicated by arrow X). As the roll 1102 travels in the X-direction through the gap between the anvils 1114a, 1114b and the horn 1110, either the anvils 1114a, 1114b or the horn 1110, or both, move toward each other to sandwich the portion of the roll 1102a therebetween. Fig. 11C illustrates the coil portion 1102a almost ready to be clamped between the horn 1110 and the anvils 1114a, 1114 b. In fig. 11D, a portion 1102a of the coil can be seen sandwiched in a U-shape between a horn 1110 and anvils 1114a, 1114 b. As shown in fig. 11D, by moving the anvils 1114a, 1114B in the directions of arrows a and B, the anvils 1114a, 1114B are clamped together while the horn 1110 vibrates rapidly up and down in the bi-directional direction shown by arrow C. This rapid up and down mechanical movement of the horn caused by the synchronized ultrasonic energy applied by the transducers 1112a, 1112b (see FEA analysis in fig. 12) causes the first and second horn contact surfaces 11120a, 1120b (best shown in fig. 11E) to "scrape" the portions of the web 1110 trapped between the seam contact surfaces 1120a, 1120b and the corresponding anvils 1114a, 1114b, such that only one pass is required to create two seals (e.g., the trailing end of the leading bag 1104d and the leading end of the next bag 1102c on the roll 1102). The advancing web 1102 needs to pause the ultrasonic welding time and then can resume sealing the next advancing package 1104c. This rapid movement simultaneously creates two uniform seals at two locations on the 1102 roll layer. As shown in fig. 11E, a gap or slot 1130b is formed in the end 1122 of the horn 1110 that can accommodate an optional blade 1116 having a sharp tip 1124 that can cut a portion 1140 of the coil 1102 while two seals are formed at the horn interface or part engagement surfaces 1120a, 1120b, as best shown in fig. 11F. This dual action is called "cutting and sealing" because both operations are performed simultaneously, thereby increasing the throughput and speed of inter-bag slitting. The portion between the two seals is referred to as inter-seal gap 1102a. The anvil 1114a has a surface 1123, the surface 1123 pressing against the portion 1104 of the roll 1102 adjacent to a first portion contact surface 1120a of the horn 1110. The anvil 1114b also has a surface 1125, the surface 1125 pressing against the portion 1104 of the roll 1102 adjacent to the second part contact surface 1120b of the horn 1110.

Fig. 12 is a graphical representation of Finite Element Analysis (FEA) of the horn 1110 as the dual transducers 1112a, 1112b transmit synchronized ultrasonic energy into the horn 1110. The stress and strain of the metal of the bonding tool 1110 causes it to expand and contract rapidly, which creates a scraping action, allowing the interfaces 1120a, 1120b to move back and forth rapidly. This friction produces uniform thermal energy that rapidly creates an air seal at both locations on the web at the interface 1120a, 1120 b. The deformation of the metal is exaggerated in this model for ease of illustration.

Fig. 13A is a perspective view of an ultrasonic-assisted "cut and seal" assembly 1300 having dual ultrasonic transducers 1312a, 1312b that apply synchronized ultrasonic energy to a resonant horn 1310, with a multi-layer roll, such as roll 1102, sandwiched between the resonant horn 1310 and anvil 1314. The welding head 1310 may also be driven by a single ultrasonic transducer if the welding power used is not large. Fig. 14A is a perspective view of an ultrasonically assisted "cut and seal" assembly 1400 having dual ultrasonic transducers 1412a, 1412b that apply synchronized ultrasonic energy to a resonant horn 1410, with a multi-layered roll, such as roll 1102, sandwiched between the resonant horn 1410 and an anvil 1414. As can be seen by comparing fig. 13A and 14A, resonant horn 1310 in fig. 13A has short grooves 1311, 1313 formed along the end edges of horn 1310. As shown in fig. 13C, a resonant horn with a short groove near the output face has a node (region of least motion) near the inner side of the groove and an anti-node (region of greatest motion) on the outer surface of the horn. This movement produces a back and forth scraping action as shown in fig. 13C. The resonant horn 1410 in fig. 14A has an elongated slot 1411 formed along the body of the horn 1410, but the other components 1300, 1400 are identical. An optional blade 1316 is shown in anvil 1315, which may be used to slit between adjacent seals, the space between the seals being defined by a gap 1322 between the fingers of welding head 1310 and anvil 1314, as shown in fig. 13B. Fig. 13C illustrates two FEA images of bonding tool 1310 when out-of-phase ultrasonic energy is applied into the body of bonding tool 1310 through dual transducers 1312a, 1312 b. For ease of illustration, the deformation or displacement of bonding tool 1310 has been exaggerated, but the image illustrates how bonding tool 1310 moves rapidly back and forth in the directions of arrows a and B to create a wiping action on its end surfaces. The heat generated by the scraping generated by the ultrasonic energy when pressed against the anvil 1314 causes the films sandwiched between the horn 1310 and the anvil 1314 to be sealed and welded together. Such sealing may be accomplished by driving the welding head in and out or by continuously rotating the welding head, with the welding head contacting the film twice per revolution.

Fig. 14B illustrates two FEA images of a resonant horn 1410 shown in fig. 14A. Likewise, as the out-of-phase ultrasonic energy passes through the body of the welding head 1410 through the dual transducers 1412a, 1412b, the dual transducers 1412a, 1412b transmit ultrasonic energy having synchronized frequencies toward each other into the welding head 1410, exaggerating the direction of motion or deformation of the welding head 1410. The grooves 1411 deform slightly, thereby producing mechanical movement of the welding head 1410, referred to herein as scraping on the end faces of the welding head 1410, as they are pressed against the anvil 1414. The welding head 1410 may be driven into and out of, or rotated continuously, such that the welding head contacts the film twice per rotation. In fig. 14B, the horn expansion creates a node (area of minimal movement) and passes through the slot. As shown in fig. 14B, the anti-node (region of maximum motion) appears on the output face of the horn, creating a back and forth wiping action.

Fig. 15A is a top or bottom view of a prior art cutting blade 1502 sandwiched between two ultrasonically welded triad assemblies 1512a, 1512 b. Fig. 15B is a side view of the cutting blade 1502 and ultrasonic welding stack assemblies 1512a, 1512B shown in fig. 15A. The cutting blade 1502 has two cutting edges 1524a, 1524b with sharpness configured to cut through, for example, a block of food substance. The type of food substance is not important to the present disclosure. A disadvantage of this prior art approach is that the cutting blade 1502 is affected by multiple nodes (regions of minimal motion activity) along the axis (and cutting edge) of the blade 1502. As a result, there may be very poor cuts at and near these nodes. The embodiments shown in fig. 16-18 next eliminate these undesirable nodes along the cutting edge and ensure consistent amplitude of the cutting edge along the cutting blade. In addition, the cutting blade 1502 shown in fig. 15A and 15B is not suitable for cutting a material having a thickness equal to or greater than the height of the cutting blade 1502.

Fig. 16A is a perspective view of a rotatable resonant cutting blade 1602 of a synchronized cutting assembly 1600, the synchronized cutting assembly 1600 sandwiched between two ultrasonic welding stack assemblies 1612a, 1612b, the respective transducers of the ultrasonic welding stack assemblies 1612a, 1612b outputting synchronized ultrasonic energy (frequency and phase) into the cutting blade 1602, the cutting blade 1602 operating like a resonant horn. The horn shown in fig. 16A may also be driven by a single ultrasonic transducer at lower power requirements. Fig. 16B is a side view of the cutting blade assembly 1600 shown in fig. 16A. 16a. Fig. 16C is an end view of the cutting blade assembly 1600 shown in fig. 16A. In this example, cutting blade 1602 has an elongated slot similar to that shown in horn 1110 of fig. 11A, and is configurable to rotate about the axis of triplets 1612a, 1612b and cutting blade 1602. An example of such rotation is illustrated in fig. 17A to 17C. As the cutting blade 1602 cuts through the substance, both triad assemblies 1612a, 1612b simultaneously introduce synchronized ultrasonic energy into the cutting blade 1602, causing the blade 1602 to vibrate in a push-pull manner toward one triad 1612a and away from the other triad 1612b, and in a push-pull manner away from one triad 1612a and toward the other triad 1612 b. In addition to producing a consistent, uniform amplitude along the cutting edges 1624a, 1624b of the cutting blade 1602, another advantage of the blade 1602 is that it is capable of cutting material having a thickness that exceeds the height of the blade 1602. An example of this embodiment is shown in fig. 17.

Fig. 17A is a perspective view of the rotatable cutting blade assembly 1600 shown in fig. 16A, the rotatable cutting blade assembly 1600 cutting through thicker blocks 1700, such as food. Fig. 17B is an end view of the rotatable cutting blade assembly 1600 shown in fig. 17A, wherein double ultrasonic welding triad assemblies 1612a, 1612B are visible. Fig. 17C is a side view of the rotatable cutting blade assembly 1600 shown in fig. 17A. The entire cutting blade assembly 1600, along with the blade sets 1612a, 1612b, may be configured to rotate about an axis passing through the blade sets 1612a, 1612b and the blades 1602, which facilitates cutting through thick matter, even matter having a thickness exceeding the height of the blades 1602. When the blade 1602 is subjected to push-pull vibration to slice or cut through the substance 1700 by simultaneous application of synchronized energy from the triplets 1612a, 1612b, the blade 1602 may rotate slightly to ensure that the cut is straight and accommodates the non-flat profile of the blade 1602.

Fig. 18A is a functional diagram of a cutting blade 1602 configured to cut through a substance 1800 having a thickness T1 from a top or bottom cutting blade surface 1624a, 1624 b. In this example, T1 is less than the height of blade 1602, and either of the cutting surfaces 1624a, 1624b of cutting blade 1602 may be cutting substance 1800 into pieces, such as 1850a, 1850b, 1850c, etc.

Fig. 18B is a functional illustration of a cutting blade 1602 configured to cut through a substance 1802 having a thickness T2> > T1 and also greater than the height of the cutting blade 1602. This embodiment demonstrates that the synchronized ultrasonic energy can be applied to a cutting blade having a height less than the thickness of the material being cut using the synchronized ultrasonic stack herein to produce segmented material masses 1852a, 1852b, 1852c, etc.

Fig. 18C is a functional diagram showing how cutting blade 1602 can be rotated to cut mass 1804 at least twice per rotation of the entire cutting blade 1602 to produce segmented mass 1804a, 1804b, 1804C. During the first half of the rotation, one of the cutting blade edges 1624a cuts through the object 1804 and during the second half of the rotation, the other cutting blade edge 1624b cuts through the object 1804. The thickness of the substance 1804 is less than half the height of the cutting blade 1602 to ensure that rotation of the blade 1602 does not interfere with the passing substance 1804 moving relative to the blade 1602.

Fig. 19A-19C, 20A-20C, and 21 illustrate different types of paddle heads similar to those shown in fig. 12, 13A-13C, and 14A-14B. Because the paddle horn performs the "scraping" motion described above, its entire surface in contact with the part or parts to be welded is swiftly rubbed back and forth in the transverse direction (see arrows a and B in fig. 13C and 14B), ultrasonic energy may be applied to the part or parts to be welded across the entire exposed edge or end surface of the horn. The welding head shown in fig. 12, 13A-13C, and 14A-14B also has the advantage that the entire edge surface from one end of the welding head to the other can be used to apply ultrasonic energy to or into one or more parts to be welded. The paddle covers a much larger welding area allowing for longer or larger parts to be joined, such as a film attached to the top of the container, and it can complete two welding cycles when the paddle is rotated a single 360 degrees. In contrast to conventional sealing applications, there is no need for heat or no need to apply heat to the weld interface, and the ultrasonic energy is sufficient to bond the parts together, such as welding the film to the container, or welding two films together without the application of any heat energy. The paddle-like horn herein allows the horn to expand and contract along its transverse dimension (orthogonal to its axis of rotation) creating a "scraping" motion along the entire weld interface, whereas conventional expansion motions can only achieve a small and less reliable weld area.

The paddle heads disclosed herein are particularly effective in sealing non-uniform film layers, for example, when the total seal thickness varies along the length of the weld. In general, conventional approaches do not produce a uniform weld with such non-uniform thickness; however, with the ultrasonically driven paddle heads disclosed herein, the weld seal is uniform and sealed.

The horn may be made of metal and may be rigidly mounted to a fixed frame or structure such that rotation of the horn is uniform and not prone to wobble, which has the advantages of faster speed, higher weld quality, and better consistency and repeatability for applications involving packaging and non-woven applications requiring thousands of welds.

Fig. 19A and 119B illustrate two different blade "cross seal" type bonding tools 1910 having two elongated slots 1911 transverse to the axis of blade rotation. Bonding tool 1910 in fig. 19A has a plurality of protrusions 1936, while bonding tool 1910 in fig. 19B has a single protrusion 1934 along an edge surface of bonding tool 1910. The protrusions 1934 allow for the use of the same horn 1910 to weld a variety of different types of products, and can be designed such that the weld area is much larger than a conventional scratch-type horn. Ultrasonic energy is available along the axis of rotation of the horn throughout the length 1924 of the horn to achieve a large area weld. Dual ultrasonic modulators 1912a, 1912b, connected to respective dual ultrasonic transducers (e.g., transducers 2112a, 2112b as shown in fig. 21), apply synchronized ultrasonic energy to horn 1910 that reaches the entire end or edge face of horn 1910 on both sides of the paddle parallel to the axis of rotation. Fig. 19C is an enlarged illustration of a FEA analysis of bonding tool 1910, which illustrates how grooves 1911 allow bonding tool 1910 to expand and contract laterally along its axis of rotation to create a back-and-forth wiping motion along the entire face edge of bonding tool 1910. As bonding tool 1910 applies ultrasonic energy across bonding tool 1910, optional protrusions 1934, 136 rub back and forth rapidly along the entire welding surface with bonding tool 1910.

Fig. 20A, 20B, and 20C are schematic illustrations of FEA analysis (for ease of discussion) of a bonding tool 2010 having a different number of grooves 2011. The number of slots 2011 is commensurate with the length of the bonding tool 2010, the longer the bonding tool, the more slots 2011 open along its length as shown. In each case, welding is accomplished along the entire length 2024 of the exposed face edge of the bonding tool 2010. Dual ultrasonic modulators 2012a, 2012b connected to respective ultrasonic transducers (e.g., the transducers 2112a, 2112b as shown in fig. 21) apply synchronized ultrasonic energy to the horn 2010 that reaches the entire end or edge face of both sides of the paddle horn 2010 parallel to the axis of rotation.

Fig. 21 shows another type of paddle 2110 that is capable of performing a cross seam welding operation without the use of heat, with three key slots 2111 open to the welding head, with counterbores 2113 at each end of the three key slots to facilitate lateral movement (in the direction of arrow H) along the exposed edge surfaces 2130A, 2130B of the welding head 2110. The dual ultrasonic transducers 2112a, 2112b, coupled to ultrasonic modulators, apply synchronized ultrasonic energy to the horn 2110, which reaches the entire end or edge face on both sides of the paddle horn 2110 to effect welding and form a uniform seal along the entire length of the end or edge face on both sides of the horn 2110. Alternatively, if only one side is used for sealing, the first side may be changed to the other side as it wears. In this example, the horn will be flipped 180 degrees so that the unused side is available to continue sealing, effectively doubling the horn operating life.

The welding heads shown in fig. 13C, 14B, 16A, 19A-19C, 20A-20C, and 21 described above produce a wiping motion due to design principles discussed below. The sonotrode is designed with a natural resonance that is excited in operation. There are many resonances in structures of this size. Computer simulation may be used to tune the horn structure to have resonance of the desired direction of motion and uniformity, while keeping any other undesired resonance frequencies away from the desired resonance frequency.

It should be noted that these resonances exist in the horn structure independent of the amplitude modulator and transducer connected thereto. The purpose of the amplitude modulator is to provide mechanical support and to provide input vibrations along with the transducer to excite the natural resonances described above. Amplitude modulators and transducers have no significant effect on the direction of motion of the resonance, only on its amplitude.

Fig. 22 and 23 illustrate two prior art conventional longitudinally extending resonant horn designs in which the direction of motion of the structure is designed as the direction of horn elongation. Simple elongate ultrasonic horns have been used in the art for many years. In the FEA example of a prior art longitudinally extending horn 2210 shown in FIG. 22, vertically oriented horn 2210 has a height corresponding to a half wavelength (λ/2) of the applied ultrasonic frequency and has a node 2252 at an approximate center region (λ/4) of horn 2210. Regions of minimum or minimum amplitude and maximum or maximum strain at the nodes. Two anti-nodes 2250, 2254 occur at the top and bottom regions of the elongate bonding tool. An anti-node is a region with maximum amplitude and minimum strain. Because of the location of the nodes in the middle and the location of the anti-nodes at either end of bonding tool 2210, bonding tool 2210 extends along its length, as shown in fig. 22, to vibrate in an up-down direction at the frequency imposed by an ultrasonic transducer (not shown).

Similarly, fig. 23 shows a prior art transverse metal welding horn 2310 having a length corresponding to one wavelength (λ) of the applied ultrasonic frequency. Here, along the length of the weld head 2310, two nodes 2352, 2354 occur at approximately λ/4 and 3λ/4, and two anti-nodes 2356, 2358 are located at the ends of the weld head 2310 where they are typically secured to, for example, an amplitude modulator or other securing structure. Vibration occurs along segment 2362, producing an elongated motion of weld head 2310 along its length. The elongated motion created by the prior art bonding tool shown in fig. 22 and 23 will not create a wiping motion across the entire width of the bonding tool (e.g., its longest dimension) as disclosed herein, but only in a much smaller limited area.

A scratch-off type weld head using an elongated weld head but in contact with the sides produces a scratch effect, as shown in fig. 13A-14B and 19A-21. Fig. 24 illustrates a FEA analysis of a weld head 2400 similar to that shown above that produces a back and forth wiping action. The horn 2400 may be made of metal, including titanium, and is a vertically oriented horn having a height corresponding to one wavelength (λ) of the applied ultrasonic frequency (e.g., 20 kHz). Exemplary height dimensions include 4.6 inches/half wavelength (lambda/2) +/-0.25 inches, depending on the overall construction of the bonding tool. It should be emphasized that these dimensions are merely exemplary and those skilled in the art will know how to adjust the dimensions according to the wavelength and frequency of the applied ultrasonic energy using the teachings of the present disclosure. To create a scraping effect, two sets of nodes 2450, 2452 (regions of minimal or minimal amplitude and of maximal or maximal strain) are arranged at each λ/4 section along the height (1λ) of the welding head 2400. Instead, two anti-nodes 2454, 2456 are provided at either end 2430a, 2430b of the horn 2400. The welding head 2400 is fixed between the points 2440, 2442, for example by means of a respective amplitude modulator (not shown). Due to the location of the nodes 2450, 2452 and anti-nodes 2454, 2456, a single ultrasonic transducer (not shown) may drive the horn 2400 to produce a scraping action along the ends 2430a, 2430b, these nodes 2450, 2452 and anti-nodes 2454, 2456 cooperating even with a single ultrasonic transducer to produce a scraping action.

A plurality of grooves 2411 may be formed along the length of the weld head 2400, and as described above, the number of grooves may be related to the length of the weld head 2400.

For a dual-bearing paddle horn, the selection of one or both transducers is based on the desired input power level. If two transducers are used, the choice of push/push or push/pull is determined by the motion designed into the horn, whereas in two horn applications, push/push or push/pull may be chosen independently of the design of the horn. The two horn embodiments have the unique advantages described above in fig. 2-3B.

While some materials suitable for sealing or welding using the simultaneous twin horn ultrasonic energy application disclosed herein have been described herein, including plastics and nonwoven films, the present disclosure contemplates sealing or welding together other types of the same or different materials, including stand-up pouch packages made from polyester printed onto aluminum and then laminated to polyethylene, metals including aluminum, metal foils, fabrics, films, polyethylene coated fiberboard or liquid cardboard, and the like. The scraping motion or transverse seals herein, as well as all other materials particularly suitable for single layer plastic films, PLA, bioplastic, biopolymers, biodegradable polymers or recyclable materials, etc., are not particularly suitable materials for heat sealing, but can be effectively sealed by the application of ultrasonic energy. Thinner films may also be uniformly and consistently sealed according to the methods disclosed herein. Conventional heat sealing techniques can only be used with several types of films of a particular width weld and thickness, with the minimum weld width being much greater than the width allowed by the ultrasonic sealing technique disclosed herein.

Advantages of the systems and methods disclosed herein include:

the processing speed is increased: in contrast to conventional ultrasonic welding techniques that require multiple cycles and application of ultrasonic energy, the systems and methods herein require only one cycle to create an airtight seal for various packages, geometries, and materials.

Seals of the same or different materials are suitable: the hermetic seal is achieved at one time by synchronized ultrasonic energy applied by two opposing welding heads, regardless of the uniformity of the material or its thickness.

The process parameter window is widened, and the consistency and repeatability of welding results are improved: because both horns apply the same ultrasonic energy (same frequency and phase) at the same time, this effectively doubles the amplitude of the energy, enabling a wider process parameter window to be achieved as compared to conventional techniques.

The production workshop is cleaner, the process is more environment-friendly (ultrasonic welding requires much less energy than heat sealing technology): ultrasound uses less energy to create a seal in one second, such as 0.35 seconds or even faster, than heat sealing techniques that require the application of thermal energy to create a seal.

New materials can be used including bioplastic and materials with poor welding compatibility: the frequency and phase synchronized twin horn device, which can be combined with a scratch and vibrate horn design, significantly expands the range of combinations of material types, interfaces and geometries that can be used to produce consistently high quality seals.

Waste and delay are reduced; yield improvement: conventional techniques create inconsistent seals, sometimes with minor leaks, or may create burns or other cosmetic defects, requiring some parts to be scrapped, thereby reducing overall yield.

Narrower seals can save material: the interface or area to be sealed may be considerably smaller than conventional techniques, so that the total amount of material may be reduced. When sealing or welding millions of parts, a slight reduction in the material of each part results in a significant reduction in the total amount of material.

Eliminating channel leakage: conventional techniques may create minor leaks that may present a risk of air, pathogens, and/or molds, but the systems and methods of the present invention eliminate leaks without creating any cosmetic blemishes and without hot stamping at the interface of the seal. This may extend the shelf life of the product within the package/container and the product transportation distance may be longer. Compared to heat sealing, the ultrasonic technique of the present invention reduces the leakage rate from 1.5% to about 0.87-0.50%, saving millions of packages each year, thereby reducing landfill waste.

Reducing the complexity of the manufacturing process, such as welding the spout to the pouch, can be accomplished in a single pass or cycle using this technique. At present, the welding of the spout to the bag can be completed by three passes or cycles by adopting the traditional ultrasonic welding technology.

Ultrasonic energy (vibration) of the ultrasonic welding triplet may eliminate liquid or product impurities in the sealing area. Liquid residue between the two end seals on a vertical or horizontal packaging machine (e.g., in a brick box filling line) that is desired to be eliminated may also be eliminated.

Unlike heat sealing, ultrasonic sealing only generates heat in the sealing area, and does not exceed the sealing area. For applications such as wet foods containing proteins and sugar-containing beverages in sachets, e.g. salad or powdered products, it is important that no thermal energy is introduced into the contents during the sealing process. The use of ultrasonic energy according to the disclosure herein may prevent heat transfer into the product contents. In ultrasonic sealing, the molecular layers at the seal are already bonded together before heat conduction can diffuse into the package contents or materials. Using the ultrasound technique herein, the package may be more "gently" closed for the type of package and supply material. Shrinkage and leakage are minimized or completely eliminated. The vibratory motion of the ultrasonic technique herein may also cause potential contaminants to be removed in the sealed area by vibration. This is not possible with conventional heat sealing processes.

In addition, higher accuracy and numerical parameter control options can be obtained using the ultrasound techniques disclosed herein. Allowing for adjustment of temperature, pressure and time settings in view of the heat seal application; the ultrasound applications disclosed herein have the following parameters that can be adjusted with extremely high precision, as well as using digital control: operating frequency, die amplitude, welding mode (time, energy, or distance by collapse), speed, trigger force, sealing force, dwell time, reject limit, and data acquisition for quality assurance, traceability, and regulatory requirements.

As described above, the ultrasound embodiments disclosed herein result in smaller package sizes, smaller seal widths, and thus save material for each package. An example of this savings is illustrated in table 1 below:

TABLE 1

Table 2 below shows the total power savings, reducing the carbon footprint using the ultrasound embodiments disclosed herein:

the ultrasound embodiments disclosed herein are particularly applicable to single or composite materials having a single layer rather than multiple layers. But single materials are prone to film shrinkage due to thermal and mechanical instability of the support layer. As a result, the appearance of the sealed seam may be compromised. Ultrasonic sealing counteracts this by using a cold mold that effectively reduces or avoids downtime and consumables such as high temperature teflon tape that some conventional processes have difficulty avoiding. Ultrasonic energy is only required during the sealing time and therefore does not need to have high standby power consumption as in conventional heat sealing processes. The mold in ultrasound applications is ready for immediate use without having to first preheat.

Referring to fig. 25, an ultrasonic welding system 2500 in accordance with some embodiments of the present disclosure is illustrated. The system 2500 includes a first welding head 2510, a second welding head 2530, a plurality of transducers 2550A-2530D, a plurality of amplitude modulators 2560A-2560D, a controller 2570, and a memory 2580. As described herein, the system 2500 can be used to ultrasonically weld one or more parts (e.g., any of the exemplary parts described herein).

The first welding head 2510 and the second welding head 2530 are the same or similar to other welding heads described herein (e.g., welding head 1410). The first 2510 and second 2530 welding heads may be rotated 360 degrees about their respective longitudinal axes (e.g., by one or more motors or drives) such that the part to be welded may pass between the first 2510 and second 2530 welding heads and contact or conform to the respective part contact surfaces of the first 2510 and second 2530 welding heads. Transducers 2550A-2550D apply ultrasonic energy to first horn 2510 and second horn 2530 such that as a part passes between the respective part interfaces of first horn 2510 and second horn 2530, the respective part interfaces vibrate back and forth in a scraping motion to form a weld. The ultrasonic energy may be applied during rotation of first horn 2510 and second horn 2530.

A plurality of slots 2516a-2516B are formed along a major surface of first bonding tool 2510, identical or similar to slots 1411 (fig. 14A-14B) described above. A plurality of apertures 2518A-2518D also open along the same major surface of first bonding tool 2510. During a welding operation, the plurality of slots 2516a-2516b and the plurality of holes 2518a-2518d may deform slightly, thereby allowing mechanical movement of the weld head 2510, which is described herein as scraping on the first and second part contact surfaces 2512, 2514 of the weld head 2510.

26A-26B, a bonding tool one 2510 includes a first part contact surface 2512, a second part contact surface 2514, a plurality of slots 2516A-2516B and a plurality of holes 2518A-2518D. As described herein, first part contact surface 2512 and second part contact surface 2514 vibrate back and forth along their lengths in response to ultrasonic energy applied to horn one 2510 (e.g., via first transducer 2550A, second transducer 2550B, or both). As the first weld head 2510 rotates, the first and second part contact surfaces 2512, 2514 also rotate about the longitudinal axis of the first weld head 2510. For example, both the first part contact surface 2512 and the second part contact surface 2514 may contact a part or material (e.g., a film) during a single rotation of the horn one 2510 (360 degrees about the longitudinal axis).

As shown in fig. 26B, the first part contact surface 2512 of the first weld head 2510 includes a first part contact portion 2520A and a second part contact portion 2520B, the first part contact portion 2520A and the second part contact portion 2520B helping the first weld head 2510 contact the parts to be welded. When the first welding head 2510 is rotated, the first and second part contact portions 2520A, 2520B will contact the part to be welded and pull or push the part generally in the direction of rotation of the first welding head 2510. The first and second part contact portions 2520A, 2520B are each curved or angled (e.g., as opposed to straight or having a right angle) to help contact the parts to be welded. In other words, the curved or angled profile helps to contact (e.g., squeeze) the parts to be welded in a more gradual manner than if the portions were formed at right angles. This is particularly advantageous for welding relatively thin materials that may deform, tear or tear when contacted by weld head one 2510. The angle of the first part contact portion 2520A and the second part contact portion 2520B may be designed to be between about 1 degree and about 5 degrees, for example.

Second weld head 2530 is the same as or similar to first weld head 2510 described herein. As shown in fig. 27, the second weld head 2530 includes a first part contact surface 2532 and a second part contact surface 2534, the first part contact surface 2532 and the second part contact surface 2534 being the same as or similar to the first part contact surface 2512 and the second part contact surface 2514 of the first weld head 2510. The first and second part contact surfaces 2532, 2534 of the second weld head 2530 may have curved or angled part contact portions that are the same as or similar to the first weld head 2510 described above.

Referring again to fig. 25, a plurality of transducers 2550A-2530B, identical or similar to the other transducers described herein, apply ultrasonic energy to a first horn 2510 and a second horn 2530. In particular, in the example shown in fig. 25, a first transducer 2550A and a third transducer 2550C apply ultrasonic energy to a first horn 2510, while a second transducer 2550B and a fourth transducer 2550D apply ultrasonic energy to a second horn 2530. The first transducer 2550A is mounted at a first end of the first horn 2510, while the third transducer 2550C is mounted at a second end of the first horn 2510. Similarly, a second transducer 2550B is mounted on a first end of the second weld head 2530, while a fourth transducer 2550D is located on a second end of the second weld head 2530.

The plurality of modulators 2560A-2560D are identical or similar to the other modulators described herein and amplify the ultrasonic energy applied by the plurality of transducers 2550A-2550D. In the example shown in fig. 25, a first amplitude modulator 2560A is located between the first transducer 2550A and the first weld head 2510, a second amplitude modulator 2560B is located between the second transducer 2550B and the second weld head 2530, a third amplitude modulator 2560C is located between the third transducer 2550C and the first weld head 2510, and a fourth amplitude modulator 2560D is located between the fourth transducer 2550D and the first weld head 2510.

The system 2500 is illustrated in fig. 25 as including each of a first transducer 2550A, a second transducer 2550B, a third transducer 2550C, a fourth transducer 2550D, a first amplitude modulator 2560A, a second amplitude modulator 2560B, a third amplitude modulator 2560C, and a fourth amplitude modulator 2560D, but may also be configured as one or more alternative systems including less than four transducers and/or less than four amplitude modulators. For example, the first alternative system configuration may include only the first transducer 2550A and the second transducer 2550B, but not the third transducer 2550C, the fourth transducer 2550D, the first amplitude modulator 2560A, the second amplitude modulator 2560B, the third amplitude modulator 2560C, or the fourth amplitude modulator 2560D. In this first alternative system configuration, the first welding head 2510 is directly coupled to the first transducer 2550A, while the second welding head 2530 is directly coupled to the second transducer 2550B. As another example, the second alternative system configuration may include the first transducer 2550A, the second transducer 2250B, the first amplitude modulator 2560A, and the second amplitude modulator 2560B, but not the third transducer 2550C, the fourth transducer 2550D, the third amplitude modulator 2560C, or the fourth amplitude modulator 2560D. For example, the third alternative system configuration may include the first transducer, the second transducer, the third transducer, and the fourth transducer, but not the first amplitude modulator, the second amplitude modulator, the third amplitude modulator, and the fourth amplitude modulator.

The controller 2570 includes one or more processors 2572. The controller 2570 is generally used to control (e.g., activate) various components of the system 2500 (e.g., the transducers 2550A-2550D) and/or analyze data obtained and/or generated by the components of the system 2500. The processor 2572 may be a general purpose or special purpose processor or microprocessor. The controller 2570 may include any number of processors (e.g., one processor, two processors, five processors, ten processors, etc.), which may be in a single housing or mounted discretely apart from each other. The controller 2570 (or any other control system) or portion of the controller 2570 (e.g., the processor 2572 (or any other processor or portion of any other control system)) may be used to perform one or more steps of any method described and/or claimed herein. The controller 2570 may be centralized (within one such housing) or decentralized (physically distinct within two or more such housings). In such embodiments that include two or more housings that include the controller 2570, such housings may be mounted proximate to and/or remote from each other.

The memory 2580 stores machine readable instructions executable by the processor 2572 of the controller 2570. Memory 2580 may be any suitable computer-readable storage device or medium, such as a random or serial access memory device, hard disk drive, solid state drive, flash memory device, or the like. The system 2500 may include any suitable number of memory devices (e.g., one memory device, two memory devices, five memory devices, ten memory devices, etc.). As with the controller 2570, the memory 2580 may be centralized (within one such housing) or decentralized (physically distinct within two or more such housings).

As described herein, the controller 2570 can cause the plurality of transducers 2550A-2550D to apply ultrasonic energy to the first horn 2510 and the second horn 2530 can cause the corresponding part contact surfaces to vibrate back and forth in the same or different directions. Referring to fig. 27, the controller 2570 can move the first and second welding heads 2510, 2530, for example, in the direction of arrow a or arrow B or both. In some embodiments, the controller 2570 moves the first welding head 2510 in the direction of arrow a while (e.g., at a first time) moving the second welding head 2530 in the direction of arrow B. As shown, the direction of arrow a is opposite to the direction of arrow B. The controller 2570 may then move the first horn 2510 in the direction of arrow B. At the same time (e.g., at a second time after the first time), weld head two 2530 is moved in the direction of arrow a. This series of movements of welding heads one 2510 and two 2530 may be repeated one or more times. In such an embodiment, the motions of welding heads one 2510 and two 2530 may be considered out of phase.

In other embodiments, the controller 2570 moves the first welding head 2510 and the second welding head 2530 simultaneously (e.g., at a first time) in the direction of arrow a. In other words, in this embodiment, the first 2510 and second 2530 welding heads move in the same direction. In such an embodiment, the controller 2570 may also move the first 2510 and second 2530 welding heads simultaneously in the direction of arrow B (e.g., at a second time after the first time), and then repeat the series of movements one or more times. In such an embodiment, the motions of the first 2510 and second 2530 welding heads may be considered in phase.

In some embodiments, the controller 2570 controls the frequency and phase of the first path of ultrasonic energy applied to the first horn 2510 and the frequency and phase of the second path of ultrasonic energy applied to the second horn 2530, or any other combination.

In a first exemplary embodiment, the controller 2570 matches the frequency of a first path of ultrasonic energy applied to the horn first 2510 to the frequency of a second path of ultrasonic energy applied to the horn second 2530, and each path of ultrasonic waves is out of phase. In this example, the frequencies that match or synchronize are the same (e.g., both frequencies are about 20 kHz) or substantially the same (e.g., both frequencies differ from each other by within about ±2 Hz). The phase of the first path of ultrasonic energy applied to horn one 2510 is 180 degrees out of phase with the phase of the second path of ultrasonic energy applied to horn two 2530. When the applied ultrasonic energy is out of phase, welding heads one 2510 and two 2530 move in opposite directions (e.g., a first welding head 2510 moves in a first direction and a second welding head 2530 moves in a second direction opposite the first direction). The use of two welding heads (e.g., welding head one 2510 and welding head two 2530) provides a greater advantage than the use of one welding head and anvil, for example, when welding head one 2510 and welding head two 2530 are out of phase, which doubles the amplitude of the ultrasonic power applied to the part to be welded than if only one welding head were used.

In a second exemplary embodiment, the controller 2570 matches the frequency and phase of the first path of ultrasonic energy applied to the first horn 2510 to the frequency and phase of the second path of ultrasonic energy applied to the second horn 2530. The matching frequencies are the same (e.g., both frequencies are about 20 kHz) or substantially the same (e.g., both frequencies differ by within about ±2 Hz). When the phases of the applied ultrasonic energy match, the motions of welding head one 2510 and welding head two 2530 are synchronized (e.g., welding head one 2510 and welding head two 2530 move in the same direction at the same time).

In a third exemplary embodiment, the controller 2570 controls the frequency and phase of the first path of ultrasonic energy applied to the horn first 2510 and independently controls the frequency and phase of the second path of ultrasonic energy applied to the horn second 2530. For example, the controller 2570 may cause the ultrasonic frequencies of the two welding heads to be substantially the same or similar (e.g., both frequencies are within ±500 Hz). In one example, both frequencies are maintained at approximately 20kHz. While the phases are independent of each other (e.g., they are not matched or 180 degrees out of phase), the effective amplitude applied to the part to be welded is much higher than if only a single sonotrode were used (e.g., the amplitude of the two-horn solution is about 1.4 times the amplitude of a single horn than if only one of anvil and horn one 2510 and horn two 2530 were used).

In a fourth exemplary embodiment, the controller 2570 causes the frequency and phase of the first path of ultrasonic energy applied to the first horn 2510 to be substantially different from the frequency and phase of the second path of ultrasonic energy applied to the second horn 2530. In one non-limiting example, the first ultrasonic energy of horn one 2510 has a frequency of about 20kHz and the second ultrasonic energy of horn two 2530 has a frequency of about 35kHz.

The above first, second, third and fourth exemplary embodiments each assume a single controller 2570 is used, but it should be understood that multiple controllers identical or similar to 2570 may be used. For example, in the third and fourth exemplary embodiments, the first controller may be used for the first horn and the second controller may be used for the second horn.

Fig. 28 illustrates a method 2800 of welding parts according to some embodiments of the present disclosure. One or more steps or aspects of the method 2800 may be implemented using any element or aspect of the system 2500 described herein.

Step 2801 includes causing a first transducer to apply a first path of ultrasonic energy to horn first to vibrate a first part contact surface of horn first back and forth along its length. For example, the controller 2570 may cause the first transducer 2550A, the third transducer 2550C, or both to simultaneously apply a first path of ultrasonic energy to the horn one 2510. The first path of ultrasonic energy may have a first frequency controlled by the controller 2570.

Step 2802 includes causing a second transducer to apply a second path of ultrasonic energy to horn second to vibrate a second part contact surface of horn second back and forth along its length. For example, the controller 2570 may cause the second transducer 2550B, the fourth transducer 2550D, or both to simultaneously apply a second path of ultrasonic energy to the horn second 2530. The second path of ultrasonic energy may have a second frequency controlled by the controller 2570.

Step 2803 includes moving the part to be welded between a first part contact surface of a first weld head and a second part contact surface of a second weld head. For example, the controller 2570 may pass a part to be welded (e.g., a film) between the first part contact surface 2512 of the first horn 2510 and the second part contact surface 2532 of the second horn 2530. Alternatively, the controller 2570 may pass the part to be welded between the second part contact surface 2514 of the first weld head 2510 and the second part contact surface 2534 of the second weld head 2530. Step 2803 may occur before, after, or simultaneously with one or both of steps 2801 and 2802.

Step 2804 includes moving a first welding head in a first direction relative to a part to be welded at a first time. For example, the controller 2570 may move the first welding head 2510 in a first direction relative to the parts to be welded. Step 2804 may occur before, after, or concurrent with step 2801.

Step 2805 includes moving second welding head in a second direction relative to the part to be welded at a first time. As described herein, the second direction may be, for example, (1) different (e.g., opposite) from the first direction (out of phase) or (2) the same as the first direction (out of phase). Step 2805 may occur before, after, or simultaneously with one or both of steps 2804 and 2802.

The method 2800 may also include rotating the first and second welding heads about their respective longitudinal axes. For example, the controller 2570 may rotate the first welding head at a first rotational speed and the second welding head at a second rotational speed (e.g., via one or more motors or drivers). The first rotational speed and the second rotational speed may be the same or different.

One or more steps of method 2800 may be repeated one or more times to achieve multiple welds. For example, method 2800 may be repeated such that as the film passes between first and second bonding tools, each rotation of first and second bonding tools, the respective part contact surface of each bonding tool contacts the film twice.

Fig. 29 illustrates a FEA analysis of a back and forth wiping action similar to the horn 2910 described above. In this example, horn 2910 includes a first anti-node 2920A at a first end of horn 2910 (e.g., where ultrasonic energy is applied to horn 2910), a second anti-node 2920b at a second opposite end of horn 2910, a third anti-node 2920C at a first part contact surface of horn 2910, a fourth anti-node 2920d at a second part contact surface of horn 2910 opposite the first part contact surface, and anti-nodes 2920E-2920I. In addition, the nodes 2930A-2930J are located at different locations along the horn 2910. Specifically, nodes 2930A-2930E are located between the central longitudinal axis of the horn 2910 and the first part contact surface, while nodes 2930F-2930J are located between the central longitudinal axis of the horn 2910 and the second part contact surface. As described herein, an anti-node is a location in the horn 2910 where the amplitude of ultrasonic energy is at or near a maximum during operation. Instead, the node is where the amplitude of the ultrasonic energy is at or near the lowest point in the horn 2910 during operation.

One or more elements or forms or steps from one or more of the following claims 1-54, or any one or more parts thereof, may be combined with one or more elements or forms or steps from one or more of the other claims 1-54, or any one or more parts thereof, or combinations thereof, to form one or more additional embodiments and/or claims of the present disclosure.

Although the present disclosure has been described in terms of one or more specific embodiments or particular cases, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present disclosure. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the present disclosure. It is also claimed that other embodiments generated by any number of combinations of the features of the content according to the invention are also encompassed within the protection rights of the present application.

Claims

1. An ultrasonic welding system. The system is an ultrasonic transducer assembly comprising a horn and two transducers, the first and second transducers simultaneously applying ultrasonic energy to the same horn, the horn having two part contact surfaces, the first contact surface being opposite the second contact surface. The driving unit is effectively connected with the ultrasonic transducer assembly to realize the rotation of the welding head;

One or more controllers operatively coupled to the ultrasound transducer assembly and the drive unit, the one or more controllers operatively configurable to:

the drive unit is caused to rotate the horn such that the first part contact surface applies ultrasonic energy to the first part along the entire length of the first part contact surface because the first part contact surface vibrates back and forth along its length when a first path of ultrasonic energy is applied to the horn via the first transducer.

2. The system of claim 1, wherein a plurality of longitudinal slots are provided in the body of the paddle-shaped horn to facilitate the motion response of the horn part contact surface when the first ultrasonic energy is directed.

3. The system of claim 2, wherein the ultrasonic transducer is equipped with a second transducer configured to transfer a second path of ultrasonic energy to the horn, the one or more controllers configured to load the second path of ultrasonic energy to the horn simultaneously with the first path of ultrasonic energy, wherein the first path of ultrasonic energy and the second path of ultrasonic energy are synchronized in frequency and phase.

4. A system according to any one of claims 1 to 3, wherein the back and forth vibration is in a transverse direction parallel to the axis of rotation of the welding head.

5. The system of claim 2, wherein each of the elongate slots has a keyhole shape.

6. The system of any one of claims 1 to 5, wherein no external thermal energy is applied to the region when forming a weld or seal at the first part contact face.

7. A system as in claim 3, wherein the first and second ultrasonic energy are applied to the horn by first and second transducers, the first and second part contact surfaces of the horn vibrate back and forth with the direction of vibration of the contact surfaces along the axis of rotation of the horn, and the phase difference of the first and second ultrasonic energy is modulated to 180 degrees.

8. The system of claim 2, wherein the second part contact surface is on the opposite side of the weld head from the first part contact surface, and are 180 degrees apart from each other along the axis of rotation of the weld head.

9. The system of any of claims 1-8, wherein the second part contact surface is parallel to the first part contact surface.

10. The system of claim 9, further comprising a knife blade mechanism disposed between the first surface and the second surface of the anvil, the knife blade being driven by the one or more controllers to sever the first sealing region and the second sealing region at the same time as or after welding.

11. The welding head according to any one of claims 1 to 10, wherein the welding head is a resonant welding head.

12. A part manufactured using the system of any one of claims 1 to 11, wherein the part is composed of a single layer, a bio-plastic, a biodegradable or recyclable layer or material.

13. A method of vibrating a welding head relative to a part in contact with the welding head using an ultrasonic transducer, the method comprising the steps of:

applying a first path of ultrasonic energy through a first transducer to an ultrasonic transducer assembly comprising the first transducer and a horn having two contact surfaces: a first part contact surface and a second part engagement surface opposite thereto;

when the first path of ultrasonic energy is applied to the horn by the first transducer, the horn is rotated simultaneously with the application of ultrasonic energy along the entire length of the first part contact surface and the second part contact surface, causing the first part contact surface to vibrate back and forth along its length.

14. The method of claim 13, wherein the ultrasonic transducer assembly includes a second transducer that outputs a second path of ultrasonic energy, the first part contact surface of the horn vibrating back and forth in response to the application of two paths of ultrasonic energy by transducer one and transducer two.

15. The method of claim 14, further comprising applying the second path of ultrasonic energy simultaneously with the first path of ultrasonic energy through the horn, wherein the first path of ultrasonic energy and the second path of ultrasonic energy are synchronized in frequency and phase.

16. The method of any of claims 13 to 15, wherein the back and forth vibration direction is parallel to the weld head axis of rotation.

17. The method of any one of claims 13 to 16, further comprising the step of:

forming a first seal on the first part via the first part contact surface during rotation of the welding head; a second seal is formed on the second part via the second part contact surface.

18. The method of any of claims 13 to 17, wherein no external thermal energy is applied to the weld or seal at the first part contact surface when forming the weld or seal.

19. The method of claim 14, wherein the direction of movement of the vibration of the first part contact surface is along the direction of rotation of the horn, and wherein the phase of the first path of ultrasonic energy is 180 degrees out of phase with the phase of the second path of ultrasonic energy.

20. The method of claim 14 wherein the first part contact surface is parallel to the second part contact surface.

21. An ultrasonic welding system having an ultrasonic transducer assembly, the system comprising:

an ultrasonic transducer assembly includes a horn and a first transducer that can direct energy to the horn. The welding head forms a first part contact surface at the outer side edge along the length direction of the welding head, the outer side edge extending from the other side opposite to the contact surface is a second part contact surface, and the distance between the two outer side edges is the height;

wherein the horn has a height corresponding to an integer multiple of one wavelength λ of the applied ultrasonic energy and comprises at least two nodes and at least two anti-nodes, the corresponding node regions having a minimum amplitude and a maximum mechanical stress and the anti-node regions having a maximum amplitude and a minimum mechanical stress. Wherein a first node of the at least two nodes is disposed about λ/4 from the first part-engaging surface and a second node of the at least two nodes is disposed about λ/4 from the second surface, and wherein a first anti-node of the at least two anti-nodes is proximate the first part-engaging surface and a second anti-node of the at least two anti-nodes is proximate the second surface;

One or more controllers operatively coupling the ultrasound transducer assembly and the drive unit and operatively configured to:

the first transducer is used for directly or indirectly transmitting ultrasonic energy into the welding head through one or more amplitude modulators, so that the contact surface of the first part vibrates back and forth along the length, namely, the direction perpendicular to the height direction.

22. The ultrasonic welding system of claim 21, further comprising a second transducer configurable to apply ultrasonic energy having a same or different frequency and amplitude than ultrasonic energy applied by the first transducer.

23. The ultrasonic welding system of claim 21, wherein the integer is 1, and wherein the frequency of the ultrasonic energy is approximately 20kHz.

24. The system-sealed part of claim 23, which may be composed of a single layer, a bio-plastic, a biodegradable or recyclable film or material.

25. The system comprises:

the first welding head is provided with a first part contact surface;

a first ultrasonic transducer configured to apply ultrasonic energy to the first weld;

a second welding head having a second part contact surface, the second welding head being positioned relative to the first welding head such that a part to be welded can be positioned between the first part contact surface and the second part contact surface;

A second ultrasonic transducer configured to apply ultrasonic energy to the second weld;

the memory stores machine-readable instructions; and

a controller comprising one or more processors is configured to execute the machine-readable instructions to:

applying a first path of ultrasonic energy through a first welding head via the first transducer to vibrate a first part contact surface back and forth along its length;

moving the first welding head relative to the part to be welded along a first direction at a first time;

applying a second path of ultrasonic energy through the second transducer through the second horn to vibrate the second part contact surface back and forth along its length;

and enabling the welding head II to move along a second direction relative to the part to be welded at the first time.

26. The system of claim 25, wherein the first part contact surface of the first welding head comprises a first curved part contact portion and a second curved part contact portion, the first curved part contact portion and the second curved part contact portion configured to assist the first part engagement surface in engaging the part to be welded.

27. The system of claim 25, wherein the first part engagement surface of the first welding head comprises a first part contact portion having a first angle and a second part contact portion having a second angle, the first part contact portion and the second part contact portion configured to assist the first part engagement surface in engaging the part to be welded.

28. The system of claim 27, wherein the first angle and the second angle are between about 1 degree and about 5 degrees.

29. The system of any one of claims 25 to 28, wherein the first direction is different from the second direction.

30. The system of claim 29, wherein the first direction is opposite the second direction.

31. The system of claim 29 wherein the control system is further configured to move the welding head in the second direction a second time after the first time; and the second welding head moves along the first direction at the second time.

32. The system of any one of claims 25 to 28, wherein the first direction is the same as the second direction.

33. The system of claim 32, wherein the control system is further configured to move the first welding head and the second welding head in a third direction at a second time subsequent to the first time.

34. The system of any one of claims 25 to 28, wherein the controller is configurable such that the first path of ultrasonic energy has a first frequency and a first phase and such that the second path of ultrasonic energy has a second frequency and a second phase.

35. The system of claim 34, wherein the first frequency is the same as the second frequency and the first phase is the same as the second phase.

36. The system of claim 34, wherein the first frequency is the same as the second frequency and the first phase is different from the second phase.

37. The system of claim 34, wherein the first frequency is different from the second frequency and the first phase is different from the second phase.

38. The system of claim 37, wherein the first frequency and the second frequency are about 20kHz, and wherein a first path of ultrasonic energy has a first phase and a second path of ultrasonic energy has a second phase that does not match the first phase.

39. The system of claim 37, wherein the first frequency is approximately 20kHz and the second frequency is approximately 35kHz, and wherein the first path of ultrasonic energy has a first phase and the second path of ultrasonic energy has a second phase that does not match the first phase.

40. The system of any one of claims 25 to 39, further comprising:

a first amplitude modulator located between the first horn and the first ultrasonic transducer; and

And the second amplitude modulator is positioned between the second welding head and the second ultrasonic transducer.

41. The system of claim 40, further comprising:

a third ultrasonic transducer configured to apply ultrasonic energy into the first horn; and

a fourth ultrasonic transducer configured to apply ultrasonic energy into the second horn.

42. The system of claim 41, further comprising:

a third amplitude modulator located between the first horn and the third ultrasonic transducer; and

and a fourth amplitude modulator positioned between the second horn and the fourth ultrasonic transducer.

43. The system of any one of claims 25 to 39, further comprising:

44. The system of any of claims 25 to 43 wherein a first bonding tool is formed with a plurality of grooves along a major surface thereof and a second bonding tool is also formed with a plurality of grooves along a major surface thereof, at least some of the grooves having a length in a transverse direction perpendicular to the length to facilitate vibration of the first bonding tool and the second bonding tool.

45. The system of any of claims 25 to 44, wherein the first horn includes a third part contact surface opposite the first part contact surface and the second horn includes a fourth part contact surface opposite the second part contact surface, wherein the first path of ultrasonic energy causes the third part contact surface to vibrate back and forth along its length and the second path of ultrasonic energy causes the fourth part contact surface to vibrate back and forth along its length, and wherein the controller is further configured to rotate the first horn about its longitudinal axis while rotating the second horn about its longitudinal axis such that the part to be welded passes between the first part contact surface and the second part contact surface or between the third part contact surface and the fourth part contact surface.

46. The system of any of claims 25 to 45, wherein the controller is further configurable to rotate the first and second welding heads while applying the first path of ultrasonic energy to the first welding head and the second path of ultrasonic energy to the second welding head.

47. A method, comprising:

Applying a first path of ultrasonic energy to a first welding head by a first transducer so as to enable a first part contact surface of the first welding head to vibrate back and forth along the length of the first part contact surface;

applying a second path of ultrasonic energy to a second horn by a second transducer to vibrate a second part-engaging surface of the second horn back and forth along its length;

moving a part to be welded between a first part contact surface of a first welding head and a second part contact surface of a second welding head;

moving the welding head I at a first time along a first direction relative to the part to be welded; and

48. The method of claim 47, wherein the first direction is opposite the second direction.

49. The method of claim 48 further comprising moving the first weld head in the second direction a second time after the first time and moving the second weld head in the first direction at the second time.

50. The method of claim 47, wherein the first direction is the same as the second direction.

51. The method of claim 47, wherein the first path of ultrasonic energy has a first frequency and a first phase and the second path of ultrasonic energy has a second frequency and a second phase.

52. The method of claim 51, wherein the first frequency is the same as the second frequency and the first phase is the same as the second phase.

53. The method of claim 51, wherein the first frequency is different from the second frequency.

54. The method of claim 53, wherein the first frequency is about 20kHz and the second frequency is about 35kHz.