Bill Aurand, national sales manager, shares how ultrasonic welding meets the evolving needs of the medical industry.
Rinco Ultrasonics
Ultrasonic plastic welding has enjoyed widespread use as a joining technology in a wide range of end-use applications including the medical industry. It has evolved since its adoption in the early 1960s and today the process is considered fairly mature. However, the technology has witnessed breakthrough advancements over the years which have dramatically improved the performance and reliability of ultrasonics, ultimately enhancing the productivity, quality, and efficiency of the manufacturing process.
The ability to measure and control the part collapse during the weld was introduced in the 1980s and gave the technology a boost in reliability and consistency. The recent introduction of servo- driven ultrasonic actuators has also given the technology another quantum leap forward. Due to modern servo technology, the precision and flexibility of ultrasonic welding has been further enhanced to a level where meaningful weld parameter changes can be made during even the shortest of cycle times.
All of these technical advancements have delivered major improvements for the manufacturing of goods for multiple industries. One of the major benefactors of the unique capabilities of ultrasonic welding has been the medical field. Ultrasonic welding has adapted well to the medical industry’s need for high precision and cleanliness. As a result, this reliable bonding method has been used extensively to manufacture medical devices and components such as surgical instruments, liquid delivery components, hygiene products, and pharmaceutical delivery systems to name a few.
Process feedback and traceability
Rinco Ultrasonics
The ability to create hermetic seals with most thermoplastics without using adhesives or fasteners aligns well with the requirements of the medical industry. Of particular interest in the medical sector is the capability of an ultrasonic welding system to provide feedback on the weld process. Competitive assembly methods such as adhesives and thermal bonding are blind and offer no measurable proof that a quality seal has been created. The data available from ultrasonic welding systems, however, provides feedback throughout the weld process. This data is often closely monitored, with upper and lower limits set to flag suspect or bad welds.
Among the growing industry trends in medical device manufacturing is the ability to provide complete traceability of all process settings during the manufacturing of any specific part. The firm belief is that confirmation of process settings from start to finish of the various manufacturing processes will help to identify the root cause of any given product failure. Since detailed process data is available from most ultrasonic welders, this should be an easy task. Unfortunately, this hasn’t been the case. Most ultrasonic welding systems have historically allowed for the weld parameter settings to be deleted. So, the settings utilised on any given day of manufacturing can’t be confirmed.
The Rinco effect
Rinco is meeting the call of the medical market for traceability capability. The company recently released two new ultrasonic welders that are fully calibratable and offer permanent audit trails so users can track all system errors and adjustments.
The eMotion 2.0 (servo driven) and Standard 2.0 (pneumatic driven) are both ISO 13485 certified. For process traceability, the two welders offer an audit trail screen. On this screen is every process error, equipment fault, or process parameter adjustment that has ever occurred. Further, the information in the audit trail is non-volatile and cannot be deleted. This means that any process tampering that might occur, on third shift for example, can’t be denied. And because the password protection can be customised for each individual accessing the machine, precise identification of the source of the change is also available. This feature helps to remove any guesswork on determining whether an ultrasonic welder’s settings were responsible for a product failure.
The advantages and adaptability of ultrasonics in the medical sector is clearly illustrated in the latest applications. Two US-based medical OEMs are employing ultrasonics to improve quality and enhance productivity. A manufacturer of vacuum devices that remove fluids from the body in hospitals originally glued the parts together. Production was slow and gave no proof of a good assembly. The company has employed Rinco’s Standard machines and is now mass producing the devices at a rate approximately 10 times faster with superior quality results.
Another manufacturer of reagent carriers for blood analysis systems originally tried to make the cartridges with a competitor’s machine but had very poor results. Rinco’s machines, which are designed to have high precision and extreme system rigidity, made an impact on the quality of the parts. The company has since purchased dozens of machines from Rinco.
Ultrasonic welding offers many advantages for bonding thermoplastic materials. The process continues to evolve as technology advances and manufacturing requirements shift. New advanced features like audit trail capability makes the already precise and reliable process of ultrasonic welding an even better fit for use in demanding applications for the medical device market.