May 12, 2014
Medical Diagnostic Test Strips Assembled using Servo Ultrasonic Welding
A leading medical device manufacturing company uses Dukane’s iQ Series Servo driven Ultrasonic Welding System to assemble Test Strips and gets sophisticated results. Assembling mini medical devices as test strips require precise, repeatable and consistent process control. The test strips are made of two thin layers of Polyethylene Terephthalate (PET) film. Between the two layers is a mesh membrane layer carrying the diagnostic chemical. Once assembled, the test strips are placed in an analyzer. These test strips measure Total Cholesterol, HDL, Glucose, and Triglycerides.
Prior to investing in iQ Servo Ultrasonic Welder, the biggest challenge for the manufacturer was a misalignment of thin PET films during the assembly process. Scrap rate was more than 30%. Dukane’s iQ Series Servo driven Ultrasonic Welding System with patented Melt-Match® technology, fixed part alignment problem and provided accurate, repeatable and reliable process control. As a result, scrap rate came down to less than 5%. iQ Series Servo Ultrasonic Welders have provided 20+ million cycles in less than three years by using a highly effective and efficient iQ Servo digital process control.
In general, Ultrasonic process allows thin film lamination to move through the assembly without product misalignment. Multiple parameters are available for defining triggering sequence for iQ Servo system. In this particular application,iQ Servo system is programmed to trigger by minimal force. Ultrasonic horn travels at a certain speed and then slows down to a programmed controlled speed prior to coming in contact with the part. When the system reaches programmed trigger force value, the horn’s downward movement stops completely and Ultrasound signal starts. Next, the system detects a programmed drop in force, indicating that parts have begun to melt and weld continues as servo motion restarts. Part compression continues for programmed distance and speed. The above feature to control horn speed and detect melt initiation reduces the unnecessary force on thin-film walls and improves weld quality.
In the final weld phase, Servo gives the flexibility to program dynamic and/or static hold. In this application, iQ Servo System has been programmed to provide ‘Static Hold’. As a result, the press holds its final weld position for a given amount of time, without moving. This gives materials enough time to solidify without misaligning. Horn then returns to the home position or top stroke ready for a new cycle. This was the most helpful feature for these thin PET strips.
Another major advantage of using iQ Servo system is the ability to duplicate a known process on multiple iQ Servo Systems without any variation in weld results. In this application, this feature was of major benefit for the manufacturing company. They were able to install multiple iQ Servo System with their growing need without investing extra time or effort in fine-tuning the process for each setup.
Along with great product Dukane’s sales and engineering team, collaboratively work with customers to provide with the best solution for their given application. For more information on iQ Series Servo Ultrasonic Welder and other Ultrasonic Welding products visit http://www.dukane.com/us/ or call 630-797-4900.