June 1, 2010
Dukane Expands Servo-Controlled Ultrasonic Welding Line for Medical Market
Dukane has expanded its novel line of iQ servo-controlled ultrasonic welding systems for medical applications and other high-value components. The new higher-frequency welders (30, 40, and 50 kHz) are targeted for smaller medical parts such as valves, ports, filters, and implant components. These new welders also employ the company’s new Melt Match technology which delivers greater repeatability, stronger welds, easier validation calibration, and lower manufacturing cost versus standard pneumatic welders.
“Our latest iQ Servo welders reduce the opportunity to create stress in small, thinwall components and facilitate optimum welding” says Michael Johnston, National Sales and Marketing Manager. For precision parts and more delicate components, the new products weld under lower force and thrust capacity. For example, the new models (30, 40, and 50 kHz) have a maximum thrust capacity of 150 lb. which is significantly lower than the 560 lb. for the recently introduced 20-kHz model. Similarly, the new welders have a trigger force of just 0.1 lb compared to 1 lb for the 20-kHz unit.
The new welder also features a stack positive index mechanism that locks in a programmable home position for reduced cycle time and setup optimization.
The new welders for smaller medical parts complement Dukane’s newly launched line of iQ servo-controlled ultrasonic welding systems which are an industry first. They too use Dukane’s Melt-Match® technology, a unique method that precisely controls the collapse speed profile during the weld. Collapsing too slow may cause material degradation while collapsing too fast may result in cold forming. Melt Match is unique because it precisely matches the collapse speed during the melt phase. As a result, the ultrasonic propagation penetrates deeper into the bond area and the affected heat zone is larger, resulting in superior bond strength. This contrasts to typical pneumatic welders that continue to travel during the hold phase, unlike a servo-controlled welder that can either stop and/or continue to collapse a specified distance and speed during the hold phase.
This high repeatability results in fewer rejects for manufacturers. In fact, testing shows that the average standard deviation of the bond strength for filter housing parts welded on a servo unit was 1.8% compared to 6.6% for those welded on a pneumatic machine.
The iQ servo-controlled welders also offer more consistent part height unlike pneumatic welders whose continuous travel during the hold phase may affect part height. The iQ servo welder “controls the entire process”, according to Johnston, and thus the collapse standard deviation of the iQ welder is three times better than that of a pneumatic machine.
Melt-Match® technology is driven by Dukane’s new patented iQ series digital power supply, the fastest in the industry. It boasts a data processing rate of 0.5 ms which is twice as fast as competitive systems. The technology also offers an important advantage for OEMs such as medical device manufacturers who must verify that weld process controls are in tolerance. The iQ unit incorporates a true programmable servo drive mechanism for speed control. As s result, validation of the servo motion is simplified. This compares to pneumatic welders that attempt to control the weld speed via air pressure through a proportional valve device. This can be problematic because actual collapse speed during welding is a variable and validating the air pressure does not ensure that collapse speed is accurate and consistent, according to Dukane.
The iQ servo welders are FDA compliant and feature a robust mechanical design and ultra-rigid support base. There are no operator-accessible settings and all mechanical adjustments require a tool. The elimination of compressed air helps to reduce clean room air filtration and significantly lowers manufacturing cost.