Ultrasonic welding uses high-frequency sound waves to join materials together without melting them. It works by placing materials under pressure between a horn and anvil, which vibrate at ultrasonic frequencies, causing the materials' molecules to rub and form a solid bond. It is commonly used for plastics and dissimilar materials. Advantages are that it is faster than adhesives and leaves clean welds, while disadvantages are that it is limited to thin metals and not suitable for large welds. Applications include bonding thermoplastics in electronics, automotive, medical, and packaging industries.

1. ULTRASONIC
WELDING

2. Ultrasonic welding is a welding
technique whereby high-frequency
ultrasonic acoustic vibrations are
locally applied to work pieces being
held together under pressure to
create a solid state weld

4. MAIN PARTS
TRANSDUCER
Produces high frequency ultrasonic vibrations.
CONVERTOR
Converts the electrical signal into a mechanical vibration
BOOSTER
Modifies the amplitude of vibrations
SONOTRODE
Applies the mechanical vibrations to the parts to be welded

5. WORKING
The parts are placed between a fixed shaped nest (anvil)
and a sonotrode(horn) connected to a transducer, and a
~20KHz low-amplitude acoustic vibration is emitted.
Common frequencies used in ultrasonic welding of thermos
plastics are 15Khz, 20 Khz , 30 Khz, 35 Khz, 40 Khz and 70
Khz.
The ultrasonic energy melts the point contact between the
parts creating a joint.

6. Its commonly used for plastics and especially for
joining dissimilar materials
In ultrasonic welding , there are no connective bolts
, nails, soldering materials, or adhesives necessary
to bind the material together
For joining complex thermos plastics ultrasonic
welding equipment can be easily customized to fit
exact specification of the parts being welded

7. ADVANTAGES
1. It is much faster than conventional
adhesives or solvents.
2. Drying time is very quick
3. Site of weld is very clean and rarely
requires any touch-up work

8. DISADVANTAGES
1. This process is limited to small welds of
thin, malleable metals
Eg: Aluminium, Copper, Nickel..
2. Ultrasonic would not be used in welding,
pieces of a bicycle or automobile
together, due to the power levels required

9. APPLICATIONS
1. Very popular technique for bonding
thermoplastics
2. Industries including electrical and
computer, automobile and aerospace,
medical and packaging
3. microcircuit connections, sheet metal, foils,
ribbons and meshes are often joined using
ultrasonic welding
4. This type of welding is often used to build assemblies that are too
small, too complex, or too delicate for more common welding
techniques.