Sonotrode and anvil energy director grids for narrow/complex ultrasonic welds of improved durability

Abstract

A specially designed sonotrode and anvil are adapted to be used in combination for ultrasonic welding of work pieces, to produce a narrower weld region, but one exhibiting greater durability, thereby permitting use of less packaging material. The contact surfaces comprise a surface of the anvil having a plurality of energy directors, where the plurality of energy directors are arranged into a three-dimensional grid pattern to be capable of distributed vibration-transmissive contact. The energy directors may comprise a series of plateau surfaces being regularly spaced apart from each other in a first direction, and in a second direction that is orthogonal to the first direction, to form the grid pattern. The rectangular-shaped plateaus may be spaced apart by valleys. Engagement of the energy directors of the anvil with the corresponding surface of the sonotrode may cause minor elastic deformation of work pieces positioned therebetween prior to ultrasonic welding.

Claims

1. A horn and anvil combination for a form-fill-seal machine, for use in ultrasonic welding of thin film work pieces, to provide improved weld integrity in packaging liquids with reduced weld widths for reduced per-package material usage: said horn comprising: a plurality of energy directors spaced in a first direction to form a pattern, each of said, plurality of energy directors comprising a shaped plateau surface with each side of said shaped plateau surfaces configured to transition into an angled side surface; with each of said angled side surfaces of each said plateau surface connected with another side surface of an adjacent plateau surface to form a trough therebetween, except at an outer periphery of said horn; said anvil comprising: a plurality of energy directors spaced in a first direction to form a pattern, each of said plurality of energy directors comprising a shaped plateau surface with each side of said shaped plateau surface configured to transition into an angled side surface; with each of said angled side surfaces of each said plateau surface connected with another side surface of an adjacent plateau surface to form a trough therebetween, except at an outer periphery of said anvil; and wherein said plurality of energy directors of said horn and said plurality of energy directors of said anvil are configured for alignment to ultrasonically weld the work pieces, wherein said side surfaces of said horn interlock with corresponding said side surfaces of said anvil, to provide improved weld integrity with, reduced weld widths.

2. The horn and anvil combination according to claim 1 wherein said shaped plateau surface for each of said energy directors comprises a square-shaped plateau surface; and wherein said one or more side surfaces comprises a first angled side surface, a second angled side surface, a third angled side surface, and a fourth angled side surface for each of said square-shaped plateau surfaces, except at an outer periphery of said horn and except at an outer periphery of said anvil.

3. The horn and anvil combination according to claim 2 wherein said energy directors of said anvil have a spacing of approximately 0.020 inches, and have a depth from each said plateau surface to said trough of approximately 0.006 inches.

4. The horn and anvil combination according to claim 3 wherein each of said energy directors of said anvil have a width for said square-shaped plateau surfaces of approximately 0.008 inches.

5. The horn and anvil combination according to claim 4 wherein said trough comprises a radiused surface.

6. The horn and anvil combination according to claim 5 where in said interlocked energy directors of said horn and said anvil are configured to cause deformation of the work pieces to produce said improved weld integrity.

7. The horn and anvil combination according to claim 6 wherein each side of each of said rectangular-shaped plateau surfaces of said horn are oriented be at a 45 degree angle to a length-wise direction of said horn; and wherein each side of each of said rectangular-shaped plateau surfaces of said anvil are oriented be at a 45 degree angle to a length-wise direction of said anvil.

8. The horn and anvil combination according to claim 1 wherein said angled side surfaces for each said plateau surface is at a 45 degree angle with said plateau surface.

9. A horn and anvil combination, for use on a form-fill-seal machine: said horn comprising: a plurality of energy directors spaced in a first direction to form a pattern, each of said plurality of energy directors comprising a shaped plateau surface with each side of said shaped plateau surface configured to transition into an angled side surface; with each of said angled side surfaces of each said plateau surface connected with another side surface of an adjacent plateau surface to form a trough therebetween, except at an outer periphery of said horn; said anvil comprising: a plurality of energy directors spaced in a first direction to form a pattern, each of said plurality of energy directors comprising a shaped plateau surface with each side of said shaped plateau surface configured to transition into an angled side sin ace; with each of said angled side surfaces of each, said plateau surface connected with another side surface of an adjacent plateau surface to form a trough therebetween, except at an outer periphery of said anvil; and wherein said plurality of energy directors of said horn and said plurality of energy directors of said anvil are configured for alignment to ultrasonically weld thin film work pieces, wherein said side surfaces of said horn interlock with corresponding said side surfaces of said anvil, to provide improved weld integrity with reduced weld widths.

10. The horn and anvil combination according to claim 9 wherein said shaped plateau surface for each of said energy directors comprises a square-shaped plateau surface; and wherein said one or more side surfaces comprises a first angled side surface, a second angled side surface, a third angled side surface, and a fourth angled side surface for each of said square-shaped plateau surfaces, except at an outer periphery of said horn and except at an outer periphery of said anvil.

11. The horn and anvil combination according to claim 10 wherein said energy directors of said anvil have a spacing approximately 0.020 inches, and have a depth from each said plateau surface to said trough of approximately 0.006 inches.

12. The horn and anvil combination according to claim 11 wherein each of said energy directors of said anvil have a width for said square-shaped plateau surfaces of approximately 0.008 inches.

13. The horn and anvil combination according to claim 12 wherein said trough comprises a radiuses surface.

14. The born and anvil combination according to claim 13 wherein said interlocked energy directors of said horn and said anvil are configured to cause deformation of the work pieces to produce said improved weld integrity.

15. The horn and anvil combination according to claim 14 wherein each side of each of said rectangular-shaped plateau surfaces of said horn are oriented be at a 45 degree angle to a length-wise direction of said horn; and wherein each side of each of said rectangular-shaped plateau surfaces of said anvil are oriented be at a 45 degree angle to a length-wise direction of said anvil.

16. The horn and anvil combination according to claim 9 wherein said angled side surfaces for each said plateau surface is at a 45 degree angle with said plateau surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a side view of an ultrasonic welding machine, utilizing the arrangement of a converter with a booster, and a sonotrode/anvil of the present invention.

(2) FIG. 1B is a front view of the ultrasonic welding machine of FIG. 1A.

(3) FIG. 2 is an exploded view of a converter, a booster, a sonotrode, and the waffle-grid anvil used to weld straight patterns in one embodiment of the present invention.

(4) FIG. 2A is a side view of one embodiment of a horn containing a series of slotted openings.

(5) FIG. 3 is an isometric view of the waffle-grid anvil of the present invention.

(6) FIG. 4 is a top view of the anvil of FIG. 3.

(7) FIG. 5 is a side view of the anvil of FIG. 3.

(8) FIG. 6 is an end view of the anvil of FIG. 3.

(9) FIG. 7 is an enlarged detail view of anvil of FIG. 4.

(10) FIG. 8 is an enlarged detail view of the grid surface of the anvil of FIG. 7.

(11) FIG. 9 is a section cut through the anvil of FIG. 7, and is shown rotated 45 degrees clockwise.

(12) FIG. 9A a section cut through a alternative embodiment of the anvil of the present invention.

(13) FIG. 10A is a front view of an alternate embodiment of the horn of the present invention.

(14) FIG. 10B is a top view of the alternate embodiment of the horn of FIG. 10A.

(15) FIG. 10C is a bottom view of the alternate embodiment of the horn of FIG. 10A.

(16) FIG. 10D is a side view of the alternate embodiment of the horn of FIG. 10A.

(17) FIG. 10E is a section cut through the energy directors of the horn of FIG. 10A.

(18) FIG. 10F is a front view of a second alternate embodiment of the horn of the present invention.

(19) FIG. 10G is a side view of the alternate horn embodiment of FIG. 10F.

(20) FIG. 11A is a section cut through the anvil and sonotrode of the current invention, shown prior to engaging work pieces, where the engagement of sonotrode energy director plateaus are aligned with and butt against corresponding anvil energy directors plateaus.

(21) FIG. 11B shows alignment of the energy director plateaus of the sonotrode with those of the anvil, per the arrangement of FIG. 11A.

(22) FIG. 11C is a section cut through the anvil and sonotrode of the current invention, shown prior to engaging work pieces, where the engagement of sonotrode energy director plateaus are aligned to interlock with the anvil energy directors plateaus.

(23) FIG. 11D shows the interlocking alignment of the energy director plateaus of the sonotrode with those of the anvil, per the arrangement of FIG. 11C.

(24) FIG. 12 shows a prior art energy director utilized on work pieces prior to ultrasonic welding.

(25) FIG. 12A shows the prior art energy director of FIG. 12 after ultrasonic welding.

(26) FIG. 13 is an exploded view of a portion of an ultrasonic welding machine comprising converter, a booster, a sonotrode, and an alternative grid-surfaced anvil that may be used to produce contoured (non-linear) weld patterns.

(27) FIG. 14 shows a second alternative grid-surfaced anvil that may be used to produce non-linear weld geometries.

(28) FIG. 15 shows an alternative dual lane horn that accomplishes ultrasonic welding and accommodates a blade to cut through the center of the welded materials after welding in completed.

DETAILED DESCRIPTION OF INVENTION

(29) Ultrasonic welding is a process in which one or more pieces of material, very often being plastic material, mar be fused together without adhesives, mechanical fasteners, or the direct application of heat (which tends to distort larger areas that need to be welded), by instead subjecting the materials to high frequency, low amplitude vibrations. The material to be welded may have an area where the material or materials are lapped to form a seam that is sandwiched between what is typically a fixed or moveable anvil and a fixed or moveable sonotrode.

(30) As stated in the background, ultrasonic welding may be utilized for fusing metal parts, however, it is commonly used for the joining of plastic work pieces. The word plastic can refer, in the mechanical arts, to the stress/strain relationship where strain has exceeded a material-specific point at which further deformation results in a permanent change in shape, which is distinguishable from the technical description of the material plastic. Plastic material usually comprises polymers with a high molecular mass, and can be combined with other components to enhance the performance of the material for specific applications.

(31) Plastic materials fall into one of two categories-thermoplastic (or thermo-softening plastic) and thermosetting. A thermosetting polymer can be melted once only to take a certain shape, after which it cures irreversibly. Conversely, thermoplastics may be repeatedly softened or even melted upon application of sufficient heat. Thermoplastic materials may be further subdivided, based upon the structure of the polymer molecule, which determines its melting and welding characteristics, into amorphous and semi-crystalline thermoplastics. Some examples of amorphermous plastics are: acrylonitrile butadiene styrene (ABS), acrylic, polyvinylchloride (PVC), and polycarbonate (or Lexan). Some examples of semi-crystalline thermoplastic materials include: polyethylene plastic resin (PE), polypropylene (PP), polymide (PA), and polyester (linear ester plastics). The amorphous thermoplastic materials possess a randomly ordered molecular structure that is without a distinctive melting point, and therefore soften gradually to become rubbery before liquefying, and, also solidify gradually, with less of a tendency to warp or experience mold shrinkage. Conversely, semi-crystalline thermoplastics have a discrete melting point, and require a nigh level of heat energy to break down the crystalline structure at which melting occurs. The semi-crystalline thermoplastic materials, unlike amorphous polymers, remain solid until reaching its discrete melting temperature, after which they melt quickly, and also solidify quickly.

(32) Ultrasonic welding may be performed for similar materials, and sometimes even dissimilar materials, but to form a molecular bond for dissimilar materials generally requires chemical compatibility, meaning that the melt temperatures are roughly within 40 degrees Celsius and have similar molecular structure. Ultrasonic welding consists of mechanical vibrations causing friction between work piece materials that generates heat to melt the contact area therebetween, which results in the formation, upon cooling, of a homogenous molecular bond. The process requires a controlled amount of pressure to permit the vibrations to cause the friction heating, with that pressure being applied between the sonotrode and the anvil, which is the focal point of the current invention.

(33) The anvil may be secured to an appropriate fixture, while the sonotrode (otherwise known as a horn within the relevant art) comprises part of the critical array of equipment in ultrasonic welding machines known as the stack. The stack consists of a converter (also known as a transducer, but that term sometimes may also imply use as a sensor/detector), an optional booster, and the sonotrode. A converter is a device that converts one type of energy into another type of energy. Generally, the converter in the stack win either be a magnetostrictive transducer or a piezoelectric transducer. A magnetostrictive transducer uses electrical power to generate an electro-magnetic field that may cause the magnetostrictive material to vibrate. With a piezoelectric transducer, which is commonly used today, the supplied electrical power is directly converted, and more efficiently converted into longitudinal vibrations. A piezoelectric transducer consists of a number of piezoelectric ceramic discs that may be sandwiched between two metal blocks, termed front driver and back driver. Between each of the discs there is a thin metal plate, which forms the electrode. A sinusoidal electrical signaltypically 50 or 60 Hertz AC line current at 120-240 voltsis supplied to the generator or power supply. The generator or power supply then delivers a high voltage signal generally between 15,000 and 70000 hertz to the converter or transducer. The ceramic discs will expand and contract, producing an axial, peak-to-peak vibratory movement of generally between 12 to 25 m, and usually being at a frequency of either 20,000 Hertz or 35,000 Hertz, but with an often used frequency range of 15 kHz to 70 kHz. So, the transducer converts high frequency electrical energy to high frequency mechanical motion.

(34) The booster, being used as a mounting point for the stack, is also utilized to suitably alter the amplitude of the vibrations created by the transducer prior to being transmitted to the horn. The booster may either decrease or increase the amplitude of the vibrations, with such changes being known in ratio form as the gain. A one to three (1:3.0) booster triples the amplitude of the vibrations produced by the transducer, while a one to 0.5 (1:0.5) booster decreases the vibration amplitude by one-half. Boosters may be substituted in a stack to alter the gain in order to be suitable for a particular operation, as differences in the gain, may be needed for different material types and the type of work that is to be performed.

(35) The horn is the specially designed part of the stack that supplies the mechanical energy to the work pieces. It is typically made of aluminum, steel, or titanium. Aluminum tends to be used most often for low volume applications, as aluminum horns wear more quickly than ones made of titanium or steel, although some horns may be manufactured with a special hardened tip to resist local wear. Aluminum horns are also sometimes used when more rapid heat dissipation is needed. Additionally, multi-element composite horns may be used to weld parts.

(36) The length of the horn is a key aspect of its design. To ensure that the maximum vibration amplitude in the horn is in the longitudinal direction (away from the booster and toward the work pieces and anvil), the horn may contain a series of slotted openings 66 (see FIG. 2A). Also, the horn, like the booster, is a tuned component. Therefore, the wavelength of the vibrations and the length of the horn must be coordinated. In general, the length must be set to be close to an integer multiple of one-half of the wavelength being propagated through the material of the horn. Therefore the horn may be sized to be a half wavelength, a full wavelength, or multiple wavelengths in length. This arrangement ensures that sufficient amplitude will be delivered at the tip to cause adequate vibrations, in the form of expansion and contraction of the horn at its tip to create the frictional heating necessary for melting of the work pieces. This amplitude, for most horns, will typically be in the range of 30-120 m.

(37) All three elements of the stackconverter, booster, and sonotrodeare tuned to resonate at the same frequency, being the aforementioned ultrasonic frequencies. These rapid and low-amplitude frequencies, which are above the audible range, may be applied in a small welding zone to cause local melting of the thermoplastic material, due to absorption of the vibration energy. The application of ultrasonic vibrations may be for a predetermined amount of time, which is known as the weld time, or energy, which is known as the weld energy. Typically, the welding process generally requires less than one second, for fusing of the portion of the two parts on the joining line where the sonic energy is applied. To achieve adequate transmission of the vibrations from the horn through the work pieces, pressure is applied thereto by an anvil supported in a fixture, and through the use of a press.

(38) FIGS. 1A and 1B show an ultrasonic welding machine 100 utilizing the arrangement of a converter, a booster, press, and a sonotrode/anvil of the current invention. The booster 30 is often the means by which the stack is secured to the press 110, with it usually being secured to a flange or some other portion of the press 110. The converter 10 may be attached to one side of the booster 30, while the sonotrode (horn) 50 may be attached to the other side of the converter to be in proximity to the anvil 70. The material(s) that are to be fused together may be located upon anvil 70. A pneumatic system within the press 110 may cause the flange mounted stack to be translated downward so as to contact and apply pressure through the material(s) against anvil 70, during which time ultrasonic vibrations are emitted by the converter and resonate through the booster and sonotrode.

(39) FIG. 2 shows a first embodiment of the present invention, where the stack includes a converter 10, a booster 30, a sonotrode 50, and an anvil 70 that may be used to weld straight patterns. The converter 10 may be comprised of electrical connectors 11, 12, and 13. The converter 10 may also comprise a flat surface 15 from which protrudes a cylindrical connection means 16 that may be received in a corresponding cylindrical opening 31 in flat surface 32 of booster 30, for attachment of the converter to the booster. The booster 30 may have a flange 33 for use in securing the booster to press. The booster may have a second flat surface 35 with a cylindrical opening 36 therein, to receive a corresponding cylindrical protrusion 51 of the horn 50. Alternatively, the booster may have a cylindrical protrusion that is received by a cylindrical recess 51A, as seen for the alternative sonotrode 50A of FIG. 10A. The cylindrical protrusion 51 of the horn 50 may protrude from a rectangular block, having a length 53, a width 54, and a depth 55. The rectangular block may transition, at the depth 55, into a narrow rectangular block having a width 58, and being of sufficient length 59, inclusive of the filleted transition areas 52, to create a horn of total length 57. The horn 50 may have a contact surface 56 with a width 58 and length 53 designed for contact with anvil 70.

(40) The anvil 70, which may be seen in FIGS. 3-9, is configured to be supported in a fixture and be engaged by the surface 56 of sonotrode 50. Anvil 70 may be comprised of a mounting platform 71 having a width 72, length 73, and depth 74. The mounting platform 71 may be used to retain the anvil 70 in the mounting fixture. Protruding away from the mounting platform 71 may be a pedestal portion 75 that shares the same width 72 as the mounting platform, but may have a length 76 that may be shorter than, and be approximately centered upon, the length 73 of the mounting platform 71. The pedestal 75 may narrow, by a pair of radiused surfaces 77, into the engagement surface 78.

(41) As seen in the enlarged detail of the engagement surface 78 in FIGS. 7 and 8, and the section cut of FIG. 9, the engagement surface 78 of the anvil 70 comprises a specially constructed interface that is designed for receiving the vibrations emitted by the sonotrode 50 to create a narrower ultrasonic weld region which provides greater weld strength than is created by two flat continuous engagement surfaces. The engagement surface 78 comprises a plurality of specially crafted energy directors 79, but are not energy directors in the plain meaning as utilized within the relevant art. An energy director within the prior art is where the work pieces themselvesmeaning the parts to be ultrasonically weldedare created such that one part is flat and the other part comes to a sharp point (FIG. 12). In the case of the prior art energy director, with an example being shown by U.S. Pat. No. 6,066,216 to Ruppel, the pointed work piece was to provide a focal point for vibrations to produce frictional heat, and thereby provide a specific volume, of melted material to joint the two parts (FIG. 12A). With the invention herein, the anvil and sonotrode may comprise a plurality of specially constructed energy directors 79 that may be arranged into a coordinated three-dimensional grid pattern, being coordinated between the sonotrode and anvil, to thereby selectively increase the total surface area of the anvil that may be capable of distributing vibrations in a three-dimensional contact pattern of vibration-transmissive contact with the sonotrode, and which may also cause a minimal amount of deformation of the work pieces during the initial horn-to-anvil engagement (FIG. 11). The deformation may preferably be limited to a slight amount, and therefore be limited to remain within the elastic range of the material. The increase in surface area of contact may depend upon the width of the plateau surfaces used, as described hereinafter. The three-dimensional contact pattern may be ascertained by reference to FIG. 8, and FIGS. 9 and 10.

(42) The energy directors 79 of the anvil 70 may be regularly spaced apart from each other, as seen in FIG. 8. The energy directors 79 may preferably be spaced apart in a first direction that may parallel the weld line, and be similarly spaced apart in a second direction away from, or orthogonal to, the weld line to form the grid pattern. In a first embodiment, each of the energy directors 79 may comprise a plateau surface 80 that may be formed by a first angled side surface 81, a second angled side surface 82, a third angled side surface 83, and a fourth angled side surface 84, here the plateau surfaces 80 may comprise a rectangular-shape that may be oriented at a 45 degree angle to the weld line. At the meeting of adjacent side surfaces 81 and 82 of adjacent plateau surfaces 80, there may be a valley bottom or trough line 87 that may be oriented at a minus 45 degree angle with respect to the weld line and at the meeting of the adjacent side surfaces 83 and 84 of adjacent plateau surface 80, there may be a trough line 88 that may be oriented at a plus 45 degree angle with respect to the weld line.

(43) The rectangular-shaped plateau surface 80 lends itself very well to two different types of repetitive patterned engagement with the sonotrode described hereinafter however, other geometric plateau shapes may also be utilized, which would naturally alter the side-surface arrangement. Also, the rectangular-shaped plateau surfaces 80 may each be generally flat, although contoured plateau surfaces 80A, may alternatively be utilized, along with a filleted or radiused trough 87A, as seen in FIG. 9A.

(44) In a first embodiment, seen in FIG. 9, the energy directors 79 of the anvil 70 may have a span therebetween of approximately 0.020 inches, and have a depth from the plateau surface 80 to the troughs 87 or 88 of approximately 0.006 inches. The angled side surfaces may each be at an angle , that may be different for various configurations, but in the first embodiment, angled side surfaces 81, 84, 83, and 84 may be oriented such that the angle is a 45 degree angle, which, when resolved geometrically, would result in the width of the plateau surfaces 80 being 0.008 inches. Since the dimensions of the energy directors 79 may not necessarily be very large with respect to the material thicknesses being welded, the amount of deformation, discussed earlier, may similarly not be very large, and thus does not pose an issue as to tearing of the material of the work pieces, or even necessarily, issues relating to plastic deformation.

(45) The sonotrode 50 may have corresponding energy directors, as seen in FIGS. 10A-10E, and may similarly include plateau surfaces 60, as well as side surfaces 61, 62, 63, and 64. The improved sonotrode 50 and anvil 70 may be constructed to have engagement therebetween of energy directors comprising a greater surface area of contact between corresponding plateau surfaces and valleys, than the traditional flat surfaced sonotrode contacting a flat surfaced anvil. This increased surface area of contact, which may be seen from the engagement of the sonotrode and anvil with the work-pieces in FIG. 11 to cause minor elastic deformation prior to application of ultrasonic vibrations, results in more durable ultrasonic welding of two work pieces.

(46) In one embodiment of welding, being accomplished between the sonotrode and anvil of the present invention, alignment of the anvil and sonotrode, which is critical in each case, consists of having the energy director grids aligned so that the plateau surfaces of the sonotrode directly butt against plateau surfaces of the anvil (FIG. 11B). This focuses the vibration energy into a select grid pattern, so that when work pieces are inserted between the sonotrode and anvil (FIG. 11A), ultrasonic welding is achieved more rapidly and efficiently across the entire weld. The butt-surface alignment method is favorably used on thicker work pieces and thinner non-foil applications.

(47) In a second embodiment of welding according to the present invention, which is advantageous for thinner work pieces, dramatically improved weld durability is achieved by utilizing alignment between the energy director grids whereby the side surfaces of the sonotrode plateaus interlock with the side surfaces of the anvil plateaus (FIG. 11D) in a repeating 3-dimensional pattern, which may include minor elastic deformation of the work pieces. When the work pieces are inserted between the sonotrode and anvil (FIG. 11C), a three-dimensional weld results. The three-dimensional weld exhibits significantly improved durability over that of conventional ultrasonic welds. Depending on the length of the plateau surface utilized on both the anvil and sonotrode, the surface area of contact may be greater or less than the surface area of contact for flat engagement surfaces of the prior art welding machines. Even where the surface area of contact is somewhat less than that of the prior art flat engagement surfaces, increased durability of the weld results. However, where a relatively small plateau surface is used, perhaps being somewhat smaller than the one illustrated in FIGS. 9 and 11D, the surface area of contact would be significantly larger, and may therefore serve to further reduce the weld times and may also serve to further improve the weld quality/durability. The limiting case would be where the length of the plateau approaches zero, so that there would essentially be interlocking pyramid shapes, and for the sides being at a 45 degree slope, the result would be an increase in surface area of contact of approximately 41.4 percent (The mathematical formula for the surface area of a pyramid being Perimeter[Side Length][Base Area]). Another means of describing, and/or visualizing the energy director grids of the present invention, as seen in FIGS. 8-9 and 10E, is as a pyramid frustum.

(48) Since the alignment of the anvil and sonotrode in the interlocking alignment method is crucial for achieving the results offered herein, the horn 50E may preferably be designed to include a peripheral flange 65 at roughly the mid-plane of the horn. The flange 65 may permit mounting of the horn in closer proximity to the contact surface 56, rather than relying solely upon the mounting connection with the booster, or booster and converter. The need for this type of flanged horn for help with alignment is very pronounced for welding of very thin materials.

(49) FIG. 13 illustrates the usage of a sonotrode 50B and anvil 70B utilizing the energy directors of the present invention, to create an ultrasonic weld that does not follow a straight-line to create a linear weld in the form of an elongated weld having a rectangular-shaped periphery, and alternatively creates complex, nonlinear weld geometry upon a package to seal the package. FIG. 14 shows anvil 70D, which is capable of being used in the formation of yet another complex curved weld. These non-linear anvil/sonotrode combinations may be utilized to weld materials having a complex irregularly-shaped periphery, rather than the simple linear weld that is typically used, such as for a package of potato chips available at most vending machines. Use of these anvil/horn energy director grid combinations also allows for welding of materials to produce durable 3-dimensional geometries.

(50) Lastly, FIG. 15 shows an alternative dual lane horn 50C, having a first lane 50Ci and a second lane 50Cii. The dual lane horn 50C accomplishes ultrasonic welding according to the present invention, and also accommodates a blade, which may cut through the center of the welded materials along the weld line, after welding is completed, with the blade being able to bottom-out in the valley between the lanes.

(51) The examples and descriptions provided merely illustrate a preferred embodiment of the present invention. Those skilled in the art and having the benefit of the present disclosure will appreciate that further embodiments be implemented with various changes within the scope of the present invention. Other modifications, substitutions omissions and changes may be made in the design, size, materials used or proportions, operating conditions, assembly sequence, or arrangement or positioning of elements and members of the preferred embodiment without departing from the spirit of this invention.