Advanced ultrasonic welding components of co-pending application Ser. No. 12/925,652 are readily incorporated into new form-fill-seal machines, but owners of existing machines utilizing heat-seal stations were unsuccessful at swapping the sealing packages. Retrofit kits to a replace heat sealing station with an advanced ultrasonic sonotrode and anvil comprise: a housing; a linear rail fixed thereto; first and second bearing carriages being slidable upon the rail; and first and second fluidic muscles. Each of the fluidic muscles is mounted with a first end fixed to a respective housing wall, and a second end fixed to a respective bearing carriage, permitting actuation of each carriage through pressurization and depressurization of the muscles. The advanced anvil and sonotrode may be secured to respective carriages. In-line arrangements of anvil/sonotrode, bearing carriages, the first fluidic muscle, and the second fluidic muscle provides a narrow profile, permitting side-by-side kit installations for retrofits accomplishing duplex sealing on a horizontal machine.

A number of variations may include a product that may include a final part that may include a first part that may include a first face and may define at least one through hole and a second part that may include a second face, at least one stake, and at least one energy director that may be disposed between the first face and the second face wherein the first face and the second face may be abutted against one another and the at least one stake may be passed through the at least one through-hole and the first part and the second part have been ultrasonically staked and ultrasonically welded such that an ultrasonically welded interface may be formed between the first part and the second part.

In a method of using ultrasonic welding for fusion bonding of thermoplastic composites, an energy director is formed in place on a first thermoplastic substrate. The energy director can be protrusions arranged in a grid pattern over the entire weld region. The energy director can have protrusions of varying thicknesses to account for unevenness along the weld interface. Forming the energy director can be carried out by placing thermoplastic film on the first thermoplastic substrate, melting the thermoplastic film, and stamping the thermoplastic film with an energy director stamp. After the energy director is formed, the first thermoplastic substrate is ultrasonically welded to a second thermoplastic substrate with the energy director sandwiched between the first and second thermoplastic substrates.