Ultrasonic welding cylinders

The ultrasonic welding cylinders for the production of surgical masks that can be adapted to any type of rotary machine.

Due to high process speeds and reproducible weld results, the technology is mostly used for high-volume production in the textiles, medical, hygiene, filter, and general technical industries.

Optimized and repeatable weld results in terms of strength, tightness, and visual appearance can only be achieved if the combination of materials, the anvil profile, and the ultrasonic system are appropriately designed to match the process.

The resulting friction heat melts the material directly at the joining points of the individual material layers. Because of low energy consumption, the material undergoes very little thermal stress. The weld tools hardly heat up at all. The welded materials can be processed immediately, meaning that ultrasonic systems (or ultrasonic modules) can also be easily integrated into high-speed production lines.

Generation of ultrasonic vibrations

The ultrasonic generator converts the supply voltage into high frequency voltage of 20, 30, 35, 40, 70 kHz which is converted into mechanical vibrations in the converter using the piezoelectric effect.

The weld tool, referred to as sonotrode, transfers the vibrations into the joining area.

Tecnocut collaborates actively with the multinational Mecasonic the implantation of sets of integration of continuous ultrasonic welding technology.

How to develop competence in contour developments for anvil and anvil drum design?

To ensure ideal process sequences, the ultrasonic system, the material combinations, and the rotary anvil must be perfectly adjusted to one another. Correct design of the anvil drum structure represents the primary precondition for consistent weld results.

The anvil pattern is a critical factor for the required product design, particularly with regard to the contact pressure area, the geometry, and the embossing depth.

Tecnocut provides continuous support for their customers, from the first product idea through to technically sophisticated system solutions. The design of customized anvil drum structures for ideal weld quality is
backed up by near-production testing.

Which are the applications of ultrasonic welding technology?

For welding, laminating, embossing, perforating, and cutting of nonwovens, the efficient ultrasonic process ensures significant increase in productivity. Ultrasonics is completely fast and also saves energy because does not require additives. This makes any kinds of consumables, such as adhesive, unnecessary. In addition, standstill time due to cleaning of machines is prevented.

When welding nonwovens in combination with longitudinal seals, high-strength connections are established at the joint areas. Rotary ultrasonic systems are particularly suitable for joining applications in marginal areas.

Benefits / special features:

  • Additional web material transport
  • Fast processing
  • Tight and strong connection

When welding cross seals, instantaneous peak power must be precisely controlled and introduced into the joint areas in a minimum of time. For such applications, correct selection of the anvil geometry and the ultrasonic system is of particular importance.

Benefits / special features:

  • Consistent and uniformly strong connection
  • High product throughput per minute
  • Soft hand feel

Targeted joining of several layers of nonwovens by means of ultrasonics and an anvil drum with structure. Bonding of the material web is merely performed in “spots”, which prevents any adverse effects e.g. on filter properties or stretching behavior of elastic composites.

Benefits / special features:

  • Energy-saving
  • No adhesives required
  • Fast processing

With an engraved anvil drum a pattern structure is permanently embossed onto a textile surface through application of pressure. During this process additional design effects may be achieved, depending on color combinations of the material layers to be embossed.

Benefits / special features:

  • Textile hand feel is maintained
  • Low energy consumption
  • Color designs possible without additional print

Defined perforation of films and silicone layers by means of ultrasonics and an anvil drum. This ensures an increase in process speed compared to thermal processes, without any negative influence on the material.

Benefits / special features:

  • High process speeds
  • Process control
  • Fiber-free perforation

Cutting and simultaneous sealing of nonwovens in one single process ensures fiber-free joining of marginal areas. This technology is also used for splicing of material webs so that the joining point quality is suitable for end
products.

Benefits / special features:

  • Fiber-free welding of cutting edges
  • High production speeds
  • Material splices in end product-quality

Why continuous ultrasonic welding technology is the best way to achieve quality?

In ultrasonic welding mechanical vibrations are introduced into nonwovens under pressure. Molecular and boundary layer friction generates heat. Then the material starts to melt in individual spots. This reaction is accelerated by itself since the damping factor of the plasticized material increases and a larger proportion of the vibration energy is converted into heat.

The ultrasonic process is initiated by the stack. The stack is made up of the piezoelectric converter, the booster, and the weld tool (sonotrode).

The most important aspects are continuos web material, reproductibility and weld quality. Negative factors, such as thermal expansion, specific properties of the material to be processed, and different processing speeds have great influence on the quality of the weld result.

By means of a consistent reference/actual comparison of the force value, the MicrogapControl unit adjusts the weld gap accurately to less than 1 µm.
As a result, a constant and precise gap can be realized between the anvil drum with contour and the sonotrode.