Overlay
In plastic ultrasonic welding, the molecules form new cross links
Ultrasonics activates the plastic molecules – friction heat is generated

Laminating of nonwoven materials using ultrasonics

The general principle of ultrasonic welding can also be applied to nonwoven materials. The thermoplastic fibers are activated by mechanical vibrations thus melting and bonding in pre-defined patterns. A weld tool, referred to as Sonotrode, transmits the vibration into the nonwoven material. In industrial applications, ultrasonic frequencies between 20 and 35 kHz are common, with amplitudes (tool travel distances) of 10 µm to 50 µm. Processing of nonwoven materials is often performed in continuous processes at high web speed. By application of rotary tools, it is possible to achieve processing speeds of up to 800 meters/minute. A specifically engraved drum is used as welding, embossing, or cutting anvil. The contour of the anvil drum focuses the energy and precisely defines the weld spots required for the respective product.

  • Ultrasonic joining of nonwoven materials is particularly suitable for:

    • Laminating of various layers
    • Embossing
    • Separating and seaming of edges
    • Perforating of web material

    With welding of web material it is important to keep the distance between the material and the sonotrode consistent. Only then good and uniform results are possible. To ensure this, we offer a patented machine controller. It controls the travel movement of the actuator or the sonotrode via a stepper motor with very high position resolution and thus achieves that the thermally caused change at the ultrasonic tool is compensated and the force between the sonotrode and the anvil drum with contour is always kept consistent.

  • Sonotrode travel via anvil drum with contour and gap control unit MicrogapControl
    Sonotrode travel via anvil drum with contour and gap control unit MicrogapControl

BASICS of PLASTICS

PDF, 376 kB BASICS of PLASTICS in download cart file in download cart
  • Layer bonding and ADL fixation (topsheet and acquisition distribution layer)
    Layer bonding and ADL fixation (topsheet and acquisition distribution layer)
    Shape-welding with maximum layer adhesion without hard edges
    Shape-welding with maximum layer adhesion without hard edges
  • Wing attachment
    Wing attachment for hygiene products – wing attachment
    Embossing, laminating, and clean cutting of pads
    Embossing, laminating, and clean cutting of pads
  • Side seams and leg cuffs – lamination of nonwoven and elastic materials
    Side seams and leg cuffs – lamination of nonwoven and elastic materials
    Attachment of diaper tabs to the diaper chassis and welding of the fastening system – tape
    Attachment of diaper tabs to the diaper chassis and welding of the fastening system – tape