ONEX RF Hybrid generators provide better process control and consistency
The RF Welding Machine Challenge
When sealing complex medical pouches, blood bags, urinary bags and similar products, high consistency and repeatability is required. However, this isn’t the case with most RF sealing systems using standard oscillator tube RF generators. Their low frequency and harmonics don’t allow efficient power coupling; tending to dissipate power, only transferring 30-70% of total power to the load (sealing dies). Aside from the basic inefficiency of the equipment, users also experience excessive down time mainly due to arcs and constant tuning of parameters and system components due to product and die changeovers on the same equipment.
ONEX RF Automation, Duarte, CA, specializes in the design and manufacture of manual and automated RF sealing systems for medical device, automotive and other manufacturing industries. Known for its focused solutions, ONEX RF looks outside the box to develop innovative and sound solutions for process challenges such as this one.
Onik Bogosyan, president of ONEX RF Automation, explains that to improve RF sealing system efficiency, coupling methods needed a technology upgrade. “Instead of typical loading to the heat source, (which constantly created arcs due to the sensitive product nature) we looked at a unique patented solution that uses solid state generator and direct coupling technology. This is similar to high end amplifier tuning as used to obtain maximum audio wattage for quality sound,” he says. “By direct coupling we were sure we would be able to transfer our amplified signal to the source with minimum loss in transaction and precisely control the power at the load in two sealing cycles.”
The concept of direct coupling allows the RF generator to transfer power direct to the load and with the servo controlled Auto Tuner system monitor the reflective power and constantly adjust the load impedance to achieve above 92% efficiency. The system runs more efficiently and consistently, while sealing the product to achieve maximum desired quality. The goal was to consistently deliver a more reliable and controllable process.
Moving to Hybrid Generator for RF Sealing
turned to their expertise in hybrid technology. The hybrid technology immediately eliminated the arcing, down time, maintenance and operator safety issues. This in turn, eliminated the issue of quick RF power degradation, producing high quality seals with consistency and repeatability previously unknown in the RF welding industry.
“The Hybrid RF generator provides a consistent 27.12MHz high frequency signal, which is efficiently is tuned to the load using auto tuner in addition to consistency the generator power is set via analogue signal from a PLC/PC based control system” Bogosyan says. “The Hybrid RF generator and auto tuner provide consistent seal with minimal power loss. The analog signal allows the power to be set and maintained precisely throughout the seal cycle, and be quickly changed to perform a different seal cycle. Based on our experience the system uses 50% less power than RF welders based on oscillator tube technology.”
“We tested this technology on a complex application sealing a sensitive medical product,” he adds. “The material was 0.009” thick and required very precise power control to prevent arcing or over-melting, in addition to the shape and size of the product, it had a valve port and a very small 0.032” diameter tubing welded onto the pouch. Initially, we’d done power calculations based on tube style generator which came to 2.3KW power for the parameter seal and 800W to weld the tubing. But, when we tested the dies using a conventional RF generator, we could not control the power efficiently and saw high variations, arcing and material burn. When we switched to solid state generator solid state technology, we were able to achieve excellent results from the first attempt and the system utilized 50% less power compared with Tube style generator.”
Bogosyan points out that having the output power controlled by an analog signal is essential sealing medical bags or pouches with multiple port seals or component assemblies. “In many similar applications where we sealed newly introduce medical materials we were able to tune and control the RF power precisely and perform film seal with less power and without use of external source of heat suggested by the film manufacturers, resulting in a high quality seal without burns or arcs, which would have been impossible using tube style RF generators,” he says.
ONEX RF Sealers come with solid state generator US patented solid state technology that use crystal oscillator instead of vacuum tubes. ONEX RF systems come in different platforms, RF-Shuttle X2, RF- Roto M1, RF-Star M2 and RF-Galaxy inline automated systems. ONEX RF systems allow easy and fast setup of process parameters stored in the PLC/PC based control system, accessed via touch-screen menus.
Because hybrid generator technology is far less sensitive to complex material formulations, it allows ONEX RF to easily provide medical users a way to expand the envelope regarding their end products. “We have accomplished applications that were virtually impossible to seal by creating RF welding fields,” Bogosyan says. “Hyprid oscillator tube technology easily adapts to applications that couldn't be successfully done using other systems.”
Expanding RF Welding Markets
ONEX RF systems are easy to operate and validate for all medical applications. ONEX RF sealers use solid built platform and are great fit for medical and automotive applications. “Operators can be easily trained on ONEX RF systems in a day,” he says. “Any manufacturer that needs optimal RF welding/sealing at half the energy and maintenance cost will benefit using ONEX RF systems, including automotive, packaging, military, office supply, recreational, flooring, air structure, pool liners and more.”
ONEX RF-Hybrid generator technology allows customers to achieve results far beyond standard tube style RF sealing machines resulting in higher quality products and repeatable processes. “This is a revolutionary process that has been proven with many systems already in the field,” Bogosyan says.
Any difficult situation gives birth to innovation. In late 2006 we were given our first RF welding project to seal a complex medical balloon. Having no RF experience and only specializing in automation systems we contacted a few RF welding system suppliers in the US and Europe. In the initial meetings with various suppliers we were given the promises and "no problem" familiar terms. Throughout the entire development time we could not get any sufficient information from the suppliers, it was like a secret mission, even basic theory of operations was given in bits and pieces. By the time we were ready to seal suddenly the easy project became a nightmare; the process arced every 10th cycle and we had to send the dies back to the supplier we had chosen to work with at the time. They promissed to make the process work before we could purchase the system. Weeks went by and finally after calling 100 times to get feedback they replied that they are not interested in the project. No support whatsoever, no sorry, yet our commitment to our customer was carved on a stone.
We then had to start all over, at first we contacted one the best RF Generator manufacturers in Germany and they refused to sell us anything due to the fact that we shared the same customer base and that we were considered a competitor, we than had to conduct more search in RF industry and finally we found a company that had patented Solid State technology who claimed to have most efficient process in RF sealing and forming. We contacted the company and sent the samples and after getting their commitment we designed and built an RF press and sent it with the dies for testing. 3 days later we got a call to fly and see the process. When we saw the process working, we just could not believe it. The RF sealer worked like a champ, no arcs, no variations, and seal looked just perfect. We were very happy with the results and thankful that they could help us on such a short notice. The rest was a history we finished our first RF rotary sealer and delivered to our customer's site. After completing the first project we saw a great oportunity to help customers in need that were in a similar situation.
Since then we have spent lots of hours in studying and analyzing old RF welding process problems and customer issues and by combining our extensive experience in automation and knowledge inherited from our colleagues in the High Frequency field, we have been able to design and manufacture state-of-the-art RF welding systems, that allow us to solve a most inconsistency and arcing problems in the industry.
By bringing science into play, we've been able to give our customers a solid process consistency in day-to-day operations.
We do not use the term "Black Magic" anymore since we can explain and show our customers how things work, which is rather the opposite of our cometitors in the RF sealing industry. By training our customers on ONEX RF systems we've been able to eliminate the need of constant tweaking, "Trial & Errors" or dependency on external resources (the so called "RF Experts") to make the process work.
ONEX RF prides itself on using quantitative analysis and statistical process controls to deliver repeatable and reliable process helping our customers make the best RF seal each time, every time.
ONEX RF Automation offers extensive experience in machine building and catheter tip forming and hole punching applications for our medical customers. ONEX RF is proud to introduce our latest tip forming equipment.
After extensive evaluation and analysis, we have identified the following as common problems with tip forming equipment:
- Process inconsistency
- Changeover difficulties
- Variations after changeover
We have developed patent pending solutions that eliminate most problems customers have in the field. Our new system is designed to form 4 catheters at a time. The forming operation is controlled by 2KW solid state generator and the process is controlled by an industrial PC controller.
The ONEX RF team has a thorough understanding of the medical field and process development, capability to design and manufacture equipment and processes that will ease your manufacturing problems, and dedication to provide our customers with unmatched customer service. We look forward to discussing your manufacturing needs with you and working with you to exceed your expectations.
Welcome to the ONEX RF Automation RF Sealing and HF Welding Blog. Our goal is to develop interesting article and ideas for the medical, automotive, industrial, aerospace, and packaging industries relating to this technology and how RF Welding systems can simplify manufacturing processes and deliver sustained ROI for those who use it.
ONEX RF Automation designs and manufactures RF welding systems, automated assembly machines, fluid handling systems, robotic assembly and packaging systems. Our systems are manual, semi-automated, or turn-key.
We supply solutions for the medical industry including blood bag sealing systems, ostomy bag sealing equipment, as well as HF sealing machines for collection bags and sample pouches.
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