The concept of ultrasonic welding
In ultrasonic welding the sonotrode comes into contact with one of the pieces being processed, pressure is applied and vibrating ultrasonic energy passes through the material and generates friction heat on the joint between the surfaces of the two pieces. The material melts and molecular bonds are created between the two pieces. When the vibrations stop, the plastic solidifies, and the two parts are welded together.
Given the high speed of the process (a few tenths of a second), this technology is much used in cases of substantial volumes, such as, for instance, in the automotive industry, in packaging and hygiene, in medicinal products, in the toy industry, in filters and in electrotechnics.
An ultrasonic welding system is made up of the following main parts:
Voltage generator: it feeds the transducer (or converter) which generates the mechanical vibration;
Transducer (or converter): it is highly efficient and transforms the electrical energy in ultrasonic mechanical vibration (20-40kHz);
Booster: it is a metallic extension which amplifies the transducer vibration towards the sonotrode and enables mounting of the system in a nodal point;
Sonotrode: it is the vibrating part which comes into contact with one of the parts which is to be welded; it transfers ultrasonic vibration of suitable amplitude;
Press: handling, positioning and force control system applied on the sonotrode by means of the booster;
Nest / anvil: it is the support of the lower part which is to be welded and can have variable shapes and functions depending on the specific application.
Advantages of ultrasonic welding
Many are the advantages of using ultrasonic assembly. It is fast, clean, efficient, repeatable and has low energy consumption. Solvents, adhesives, mechanical fasteners or external heat are not required.
Sonotrodes and the instruments of an ultrasonic welding system can be easily replaced and optimized, thus guaranteeing flexibility and versatility which are impossible in other assembly processes. This process can significantly increase production and reduce assembly costs.
Everywave ultrasonic welding systems
BOND:WAVE is an ultrasonic welding system for plastic and synthetic fabrics. It can be mounted on manual welding stations or integrated in automated production processes. It can be equipped with various types of boosters and sonotrodes, depending on the type of plastic / fabric which is to be welded. Special sonotrodes for welding metals are also available.
Sonotrodes for welding face masks and polymer materials
Everywave can design many types of welding sonotrodes for various applications and processes through FEM.
Some examples, which follow below, are typically used for welding surgical face masks:
Compatibility, remote control
The welding system is fed and managed by the Unitech Generator TiTAKO3 WELD, which can be controlled by a PLC through a I/O Multifunction connection and remote Ethernet Modbus TCP/IP interconnection (with Industry 4.0 standards)
For all the features of the generator: unitech-italia.com/titako
Each ultrasound system is entirely designed through FEM analysis to reach the maximum power, efficiency, reliability and quality welding results.
The electric parameters of the system for the welding cycle and automated operations can be programmed and managed by remote control.