Ultrasonic assembly is a fast, clean, efficient method of assembling or
processing rigid thermoplastic parts or films and synthetic fabrics.
Various ultrasonic assembly techniques are used to join plastic
components, replacing solvents, adhesives, mechanical fasteners, or
other consumables.
Advantages and benefits of the process using Branson equipment include:
Fast, clean
Energy efficient
High productivity with lower cost than many alternate assembly methods
Ease of interface with automated assembly line production.
No need for elaborate ventilation systems to remove fumes or heat
In designing for ultrasonics, many factors must be considered,
including material, overall part size, final requirements of the part
(e.g., appearance, hermeticity, load forces), and joint design. To
obtain acceptable, repeatable welded joints, three general design
guidelines must be followed to provide the following features in your
parts:
A small initial contact area between mating surfaces.
A means for aligning the mating parts.
Proper horn contact and placement.
The two major joint designs are the energy director (left) and the shear joint (right).
Tongue and groove
Textured surface
Chisel
Interrupted energy director
Energy director perpendicular to wall
For more information on designing for ultrasonic welding, click here.
Ultrasonic assembly depends on the transmission of energy through
thermoplastic parts to generate frictional heat at the joint area. The
structure of the polymer—amorphous or semi-crystalline—is an important
factor in weldability.
Ease of welding is a function of part size and geometry, joint design,
amplitude, and fixturing. Also affecting weldability are melt
temperature, melt or flow index, stiffness, and chemical makeup.
Click here for information on the weldability of thermoplastics.
Ultrasonic vibratory energy is used in several distinct assembly and finishing techniques in addition to welding as described below.
Staking
Ultrasonically melting and reforming a thermoplastic stud to mechanically lock a dissimilar material in place. Click here for information on ultrasonic staking.
Inserting
Embedding a metal component (such as a threaded insert) in a preformed hole in a thermoplastic part. Click here for information on ultrasonic insertion.
Spot welding
An assembly technique for joining two thermoplastic components at
localized points without the necessity for preformed holes or an energy
director. Click here for information on ultrasonic spot welding.
Swaging/ forming Mechanically capturing another component of an assembly by ultrasonically melting and reforming a ridge of plastic.
Degating
The separation of injection-molded parts from their runner systems using ultrasonic vibrations. Click here for information on ultrasonic degating.
Textile/film sealing
Textile and film sealing utilize ultrasonic energy to join thin
thermoplastic films, as well as knitted, woven, and nonwoven textiles.
For information on material characteristics of thermoplastic textiles
and films, click here.
Slitting
Using ultrasonic energy to slit and edge-seal knitted, woven, and
nonwoven thermoplastic materials, leaving smooth, sealed edges that
will not unravel.
Ultrasonic assembly is a fast, clean, efficient method of assembling or
processing rigid thermoplastic parts or films and synthetic fabrics.
Various ultrasonic assembly techniques are used to join plastic
components, replacing solvents, adhesives, mechanical fasteners, or
other consumables. 
In designing for ultrasonics, many factors must be considered,
including material, overall part size, final requirements of the part
(e.g., appearance, hermeticity, load forces), and joint design. To
obtain acceptable, repeatable welded joints, three general design
guidelines must be followed to provide the following features in your
parts:
Ultrasonically melting and reforming a thermoplastic stud to mechanically lock a dissimilar material in place. 
Embedding a metal component (such as a threaded insert) in a preformed hole in a thermoplastic part. 
An assembly technique for joining two thermoplastic components at
localized points without the necessity for preformed holes or an energy
director. 
Mechanically capturing another component of an assembly by ultrasonically melting and reforming a ridge of plastic.
The separation of injection-molded parts from their runner systems using ultrasonic vibrations. 
Textile and film sealing utilize ultrasonic energy to join thin
thermoplastic films, as well as knitted, woven, and nonwoven textiles.
For information on material characteristics of thermoplastic textiles
and films, 
Using ultrasonic energy to slit and edge-seal knitted, woven, and
nonwoven thermoplastic materials, leaving smooth, sealed edges that
will not unravel.
