Continuous ultrasonic rotary welding
Ultrasonic welding allows for the assembly of two or more layers of materials that pass between a vibrating sonotrode and a rotary drum.

The figure below illustrates the ultrasonic welding technique. The rotary drum is usually made of tempered steel and has some raised sections machined into it.

The high-frequency mechanical action of the vibrating sonotrode and the compression force between the latter and the rotary drum generate heat due to the friction that is produced, directly in the area where the sonotrode comes into contact with the material.

The friction heat only welds the points where the sonotrode comes into contact with the material, providing the welded material with a high-grade of elasticity and absorbency. The very same properties that are required for medical staffs' coats, sterile clothing, nappies and other equipment used in the medical and clean room sectors.

Ultrasonic welding requires a lot less energy than thermal welding, which relies on heated rotary drums for joining the materials. As a result, ultrasonic welding is far more economical and does not require the use of consumables, adhesives, or mechanical fixing devices.