SA Instrumentation & Control | Volume 40 | September 2024

Image copyright: Beckhoff.

Drive technology on a packaging line for microbatteries

Only high-precision labelling reliably puts hearing aid batteries into a deep sleep. When packaging products as small as microbatteries, it goes without saying that precision is just as important as speed and efficiency. This is particularly true of hearing aid batteries, which can only maintain their performance by being hermetically sealed with a label to keep them in a state of deep sleep until they reach the end customer. High-precision labelling processes are key here, and this is where KOCH Pac-Systeme comes in with its packaging line equipped with Beckhoff technology for the end customer, VARTA. Pfalzgrafenweiler-based KOCH Pac-Systeme has been developing and implementing customer-specific, modular blister machines and packaging lines for the consumer goods, healthcare, and contact lens sectors for over 50 years. This also includes microbatteries, as in the case of the complete packaging line for VARTA in Ellwangen. The internationally active specialist in microbatteries uses this system to package hearing aid batteries with a special

technical feature. These zinc-air batteries lie completely dormant until they come into contact with atmospheric oxygen. Klaus Schöbel, head of Efficiency & Data Management at VARTA, explains exactly what this property of microbatteries means for packaging technology. “The positive terminal of the battery has air holes that facilitate contact with atmospheric oxygen; however, premature contact with air would cause the battery to dry out and lose its available capacity. To ensure the batteries can be delivered to the end customer without a loss of capacity, the holes have to be sealed airtight during the packaging process with protective film in the form of a label, essentially putting the batteries into a kind of deep sleep.” Jürgen Welker, director of Automation and Technology at KOCH Pac-Systeme, adds, “It is precisely this technique of being able to apply a high-quality seal with maximum precision that represents the special feature of this packaging line. A huge amount of development effort has been invested in the transfer technology and optical inspection systems to ensure that only

correctly sealed batteries are transported further in the process.”

Close cooperation for an optimal solution

The overall machine building responsibility for this sophisticated system lay with KOCH Pac-Systeme, where consistent modularisation meant that both standard machine modules, and specially developed workstations, could be used. These workstations were developed in close cooperation with VARTA to create an optimal overall solution. Michael Bühler, software engineer at KOCH Pac-Systeme, notes, “The optical control of the label position on the battery represents a clear example of where the expertise on both sides could be combined. We were able to come up with a self-optimising, camera-based system that can also handle the enormous variety of around 1500 packaging types, with an extremely low error rate of less than 0,02%.” Schöbel cites the data link to the ERP system as yet another special feature. “When the relevant production order is scanned in

22 September 2024 www.instrumentation.co.za