An ultrasonic sonotrode is the part that is put in direct contact with the materials that needs to be either cut or welded. It is usually made of titanium, aluminium or steel, its shape and size varies according to the material and the type of soldering that is needed.
Our highly qualified mechanical department allows us to provide customers with a complete service by making standard and composite sonotrode solutions, starting with their initial design.
Fill in the form above if you want a free consultation by our team of experts.
Sonotrodes Varieties
There are two main types of sonotrode: circular and rectangular. Any sonotrode that is more than 75 mm long is often built with longitudinal slots that are parallel to the acoustic wave motion. These slots are necessary to vibrations only at the single longitudinal direction that will be employed to weld and to decouple any other transversal or diagonal vibratory modes that would reduce the system’s overall efficiency by dissipating mechanical energy.
The vibrating unit gets stress at a certain frequency from the piezoelectric transducer. The aforementioned frequency is chosen to coincide precisely with the resonance frequency of the entire group, which comprises the transducer, the booster and the sonotrode.
This is a necessary choice that facilitates the amplification of the transducer’s resonance: it produces an acoustic amplitude wave around 10 μm, which traverses the booster and the ultrasonic sonotrode to be amplified. It then arrives at the end of the horn, where oscillations get over 50 μm of amplitude.
Both the ultrasonic sonotrode and the booster may be compared to two springs when they vibrate longitudinally. When a spring is contracted, both sides move and shorten its overall length, when it is subjected to tension its two end sides get away from each other and increase its length.
Visit our dedicated page and get a free consultation by filling the form.
Ultrasonic Sonotrode Nodal Point
The phenomenon described above occurs in the booster and the sonotrode: each one of them contracts and expands when they vibrate. There is however an area in both components that never moves. This is called a nodal point.
The point’s exact position depends on the shape of the actual pieces. Nodal points are not subjected to displacement, yet they are the areas where mechanical stress is applied the most, since they are nonetheless exposed to forces that contract and dilate them. A nodal point possesses the fundamental property of not being subjected to ultrasonic vibrations and therefore any displacement. Such property is implemented by choosing the nodal point as a mechanical link to connect the vibrating system to a moving rail or a robotic arm.
This allows for the possibility to move the vibrant group without interfering with the ultrasonic waves that pass through it. Otherwise there would be a dissipation of mechanical energy on the mechanical joints and a consequent decrease of the total amplification factor.
Due to the high mechanical stress that the booster and ultrasonic are subjected to, they have to be assembled with sturdy alloys that conduct acoustic vibrations in an efficient manner.
Booster and sonotrode behavior depends mainly on their length, by changing said longitude, it is possible to vary their natural resonance frequency.
Visit our YouTube channel to watch Sonic Italia’s multiple applications.
Sonotrodes Testing Phase
Prior to delivery each component goes through a testing stage using specific instruments.
Ultrasonic vibration frequency and amplitude are checked during this stage.
The details and manufacturing of ultrasonic horns are often discussed with the final client in order to get the best results. We strongly believe that close collaboration with clients is the best way to develop outstanding products.
If you want a free consultation by our experienced staff, fill in the contact form.