Originally Published MPMN April 2009

BREAKTHROUGHS

Servo-Controlled Welder Goes Head-to-Head with Pneumatic System

Shana Leonard

When it comes to welding, medical device OEMs face three main challenges, according to Dukane Corp.: process repeatability, the ability to validate and calibrate equipment, and manufacturing costs. With these challenges in mind, the company has introduced a servo-controlled ultrasonic welding system designed to address these issues more effectively than pneumatic systems.

To support its claims of servo superiority over pneumatic welders, Dukane enlisted the aid of a medical device manufacturer to conduct a comparison test. Evaluating process repeatability, the OEM performed a weld on a polycarbonate filter housing using Dukane’s servo-controlled system and then a pneumatic system. The OEM measured an average standard deviation of 6.6% by the pneumatic press and an average standard deviation of 1.9% with the servo welder, according to Dukane.
“The first thing that makes it work is having the ability to have precise control of the collapse speed, and we’re calling this Melt-Match technology,” says Mike Johnston, vice president, sales and marketing. “Unlike a pneumatic press, you have the ability to program that speed.” Johnston notes that verifying the repeatability of the collapse speed during the weld was also not previously possible with pneumatic systems.
Matching the collapse speed during the melt phase is also a critical determinant of bond strength, Johnston explains, because collapsing too slowly may result in material degradation while collapsing too quickly could cause cold forming. “What we discovered was that by optimizing speed during the melt collapse, we were able to create superior bonds,” he adds.
Along with ensuring process repeatability, Dukane sought to make the system easy to calibrate and cost-effective. To prevent accidental or unauthorized changes in calibration and validation, the welder was designed without operator controls on the machine. And, in contrast to pneumatic systems, the servo unit does not require compressed air for actuation. This feature can reduce energy costs and promotes sustainable manufacturing.

Contributing to the overall efficacy of the welder is the patented iQ series power supply. It boasts processing speeds of 0.5 ml/sec, which Dukane claims is the fastest in the industry. The system also employs iQ Explorer software and is equipped with such standard features as Ethernet connectivity, remote diagnostics, networking, multiple data storage options, and connection to SPC programs.

Dukane Corp., St. Charles, IL
www.dukcorp.com

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