Ultrasonic anchoring of diaper elastics
The innovative process creates a tunnel between the two layers of nonwoven in which the stretched elastic thread is guided. By using ultrasonics specific bonding areas are created in which the thread is partially anchored, and after cutting the product the thread relaxes and is clamped by the weld spots. A wide range of material combinations, thread counts, diameters, elongations and production speeds have been successfully tested. Easy positioning of multiple threads is another advantage of this development.
Format-dependant tools no longer necessary
This new anchoring process can be executed intermittently or continuously. Further innovations in controlling the signal of the ultrasonic generator ULTRABOND allow for “triggering” the ultrasonic energy extremely fast in the right places. Thus format-dependent tools are no longer needed, as the areas to be bonded can be configured freely while rendering a format anvil drum unnecessary. With less costs for tools and less time for format changes, the Overall Equipment Efficiency (OEE) is increased.
The standardized ultrasonic tools, called sonotrodes, in the MICROBOND CSI system offer Herrmann Ultraschall's proven MICROGAP technology. Multi-dimensional process monitoring is possible by combining the generator signal feature with the MICROGAP technology, which controls the gap in the bonding area and ensures a constant bonding quality with direct system feedback.
CEO Thomas Herrmann: “This new fixation process we call Anchoring, will support our global customers even better as they strive to make their products softer and more sustainable.”
Elastic threads are widely used in the hygiene market to reach better body comfort for the waist area or leg cuffs. Using ultrasonic technology offers multiple advantages over gluing:
- softer touch which is what consumers want
- controlled and repeatable process with high production speeds and wide web widths
- excellent creep performance and splice processing
- better stretch performance of threads as they’re not exposed to any heat during the process