SPECIAL REPORT

If you are looking for ways to reduce the size of your shop floor’s carbon footprint—and who isn’t?—Alan Profit suggests you set your sights on ultrasonic welding equipment. As the director of Rainbow Medical Engineering Ltd. (Letchworth Garden City, Herts, UK; www.rainbow-medical.eu), which supplies ultrasonic processing systems, Profit can’t be called impartial. But he does point to a number of facts to back up his assertion.

“Depending on the joining technique with which it is compared, ultrasonic welding is superior in a number of ways,” says Profit. “You don’t run into any of the environmental issues such as flammability or toxicity that are typical of adhesives and solvents.” Laser welders are not as energy efficient as ultrasonic systems, he adds, and they are not as flexible in terms of the types of polymers that can be joined together. As for hot-plate welding and other thermal processes, they consume tremendous amounts of energy, notes Profit. The reason that ultrasonic welding has a much smaller carbon footprint than those techniques is because of its intermittent nature.

“Ultrasonic equipment only requires significant energy when the welding operation is being carried out,” says Profit. “The rest of the time it consumes a few hundred milliwatts just to keep the circuits running.” By contrast, thermal-based welding systems gobble up energy before, during, and after the work cycle. “Hot-plate welders typically have a start-up time of 20 minutes, and the platen is running more or less continuously to maintain a constant temperature,” says Profit.

Energy consumption has become a concern for all major companies, adds Luigi Martini, director of strategic technologies, pharmaceutical development, at GlaxoSmithKline Pharmaceuticals (Harlow, UK; www.gsk.com). He has coauthored an article on ultrasonic welding with Profit. “Pharmaceutical companies are taking the size of their carbon footprint very seriously,” says Martini. In some ways, the rediscovery of ultrasonic energy is like the rebirth of biodiesel, he adds. “Now that petroleum is becoming more difficult to recover, people are remembering that diesel used to be derived from vegetable oil and recycled fat,” explains Martini. “In the same way, industry ‘forgot’ that ultrasonic equipment uses very little energy. The expression ‘saving the environment using forgotten technology’ comes to my mind,” says Martini.

It seems safe to say that the technology’s green credentials won’t be forgotten much longer, however. Profit and Rainbow Medical intend to see to that.