Linear actuators for ultrasonic welding

The ultrasonic welding actuators are a key component in joining systems for thermoplastic materials. In an industrial system, the actuator has the task of ensuring the precise and controlled movement of the vibrating unit towards the workpiece, applying the force required for the correct transfer of ultrasonic energy. The ultrasound technology is characterised by efficiency, speed and precision, features that make the actuator a critical element in ensuring process quality and repeatability.

Function and operating principle

A linear actuator for ultrasonic welding works in conjunction with a ultrasound generator and a vibrating unit (transducer - booster - sonotrode), forming an integrated system capable of converting electrical energy into high-frequency mechanical vibrations. The actuator, through a electro-pneumatic drive, moves the vibrating unit in a vertical direction until it comes into contact with the workpiece, exerting constant pressure during the welding phase.

Sonomax actuators are characterised by their compact and modular design, which allows easy integration into production lines semi-automated o fully automated. Robust construction and no flexing during the welding cycle ensure stable performance over time.

Advantages over other systems

The use of ultrasonic welding actuators offers numerous advantages over traditional mechanical or thermal systems:

• High precision in strength and stroke control
• Repeatability of the process even in high volume production cycles
• Reducing cycle times thanks to the speed of intervention

Technical characteristics of Sonomax actuators

The Sonomax compact linear actuators are designed to work with the generators of the SX series e PSX series (with integrated PLC), operating on frequencies from 20 kHz, 30 kHz, 35 kHz e 40 kHz. Each model is equipped with:

• Low voltage servo-controlled solenoid valve
• High-precision digital pressure regulator with filter and semi-automatic or automatic condensate drain, or compact proportional solenoid valve
• Height or proximity sensor with adjustable interval to define the start of welding
• High-precision mechanical stop and end-of-cycle sensor
• Pneumatic cylinder sized for the vibrating mass, frequency and power involved
• Function of sonotrode/position alignment to ensure geometric consistency of the weld

Industrial applications

Ultrasonic welding actuators find application in a variety of sectors:

• Automotive: welding of lights, dashboards, tanks, clips, cable guides
• Medical: production of disposable devices, sterile containers, ventilation valves
• PackagingClosure of blisters, tubes, pouches and flexible packaging
• Filtrationsplicing of membranes and technical fabrics for air and liquid filters
• Technical textiles: packaging of PPE, aprons, masks
• Electronics and SensorsEncapsulation of sensors, micro-components and boards

Thanks to the modularity of Sonomax actuators, the system can be adapted to the most diverse production layouts, with direct installation on machine frames o customised desks.

Machine specifications, frequencies and powers

Optimal actuator performance depends on the correct combination of:

• Working frequency: 20 kHz (high power for large parts), 30 kHz (versatile applications), 35 kHz (balance between power and precision), 40 kHz (maximum precision for delicate components)
• Power rating of the generator (typically 400 W to 3000 W)
• Useful stroke of the actuator (up to 100 mm, depending on the model or with greater travel on request)
• Operating pressure of the pneumatic system (adjustable, typically between 2 and 6 bar)
• Structural rigidity of the frame to prevent deformation and leakage

Sonomax solutions for the Italian and European markets

With over 20 years of experience, Sonomax Srl develops reliable, high-performance actuators to meet the needs of OEMs, line integrators and R&D departments. The approach is strongly customisablewith solutions that perfectly match the customer's specifications. The native interface with the PSX generators enables full automation of welding cycles, improving productivity and traceability.

Sonomax also offers technical assistance, training e scheduled maintenanceto ensure long-term reliability and operational continuity.

Frequently asked questions (FAQ)