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AUXILIARIES: Servo-Controlled Ultrasonic Welders

From: Plastics Technology
Issue: October 2011

Dukane Corp.’s Ultrasonics Div., St. Charles, Ill., has expanded its novel line of iQ servo-controlled ultrasonic welders for medical applications and other high-value components. New high-frequency models (30, 40, and 50 kHz) are aimed at smaller parts such as valves, ports, filters, and implant components. There’s also a larger press platform (15-kHz and super 20-kHz) for larger medical parts. These join the existing 20-kHz iQ model.

The new smaller models come with 600 to 1800 W, and the new larger model is offered with 3300 to 5000 W. These welders use Dukane’s Melt-Match technology, which precisely controls the collapse speed profile during the weld. Collapsing too slowly can cause material degradation, while collapsing too quickly can result in cold forming. Melt-Match dynamically senses the start of melting during the weld and precisely matches collapse speed to the rate of melting of the plastic. This reportedly allows the ultrasonic energy to penetrate deeper into the bond area and creates a larger affected heat zone, resulting in a stronger bond. Servo control reportedly can vary the collapse speed much more rapidly than with pneumatic systems. True programmable speed control with servo drive is much more exact than with pneumatics, the company says, which is valuable for medical manufacturers who must validate their process controls.

Servo-controlled welding also is said to provide more consistent part height than standard pneumatic welding control. The standard deviation of collapse height is one-third of that with pneumatic control, according to Dukane. In addition, Dukane’s patented iQ series digital power supply is called “the fastest in the industry,” with a data-processing rate of 0.5 millisec, reportedly twice as fast and competing systems. (For more on servo welding control, see Plastics
Technology’s article in August.)