NONWOVENS

Herrmann adds a number of sophisticated, patented techniques to improve ultrasonic bonding and cutting. Non-contact/Non-Wear allows the exact positioning of the Converter/Booster/Horn Stack and eliminates any contact between the anvil drum and the Weld Horn.

During processing, the weld horn and anvil drum heat up and expand, resulting in an undesired reduction of the gap between the weld horn and the anvil drum. Especially when cutting, when the gap is reduced to less than 1 micron, this can lead to damaging contact between the weld horn and the drum.

MICRO GAP control compensates for the thermal influences and maintains a constant gap between Weld Horn and the drum.

MICRO GAP control.
MICRO GAP control is a technology based on three independently operating control modes, Operating together, they maintain consistent quality through compensation for the thermal influences.

Force Sensor for precise gap control.
The weld horn expands due to heat build up and applies more pressure to the processed material. An electrical force sensor, integrated in the actuator unit, determines the peak force once per revolution. The controller compares the actual value to the required target value and adjusts the position of the weld horn if necessary.

Automatic gap control through inductive Sensor.
An inductive sensor can be mounted in the anvil drum. Signals are transmitted wireless from the sensor to the controller. Differences of the target value are detected and compensated immediately. The gap between weld horn and anvil drum remains constant. Damaging contact between the weld horn and the drum is eliminated.

Voltage Control eliminates contact between the weld horn and the anvil drum.
Using Voltage Control, the weld horn and the anvil drum are part of a low voltage circuit. Before the weld horn touches the anvil drum, the circuit is closed and the MICRO GAP controller initiates a programmed retraction of the weld horn. Then the weld horn is automatically advanced again step by step until the next retraction is necessary. This loop ensures that a very small gap is precisely maintained. This feature is used in combination with the force sensor and the inductive sensor to eliminate contact between weld horn and anvil drum even in case of web breaks.