High performance is not always the only focus of production. Optimum flexibility is equally important.
Just ask Fichter Maschinen GmbH (FMG). An integrator, industrial machine builder and contract manufacturer based in Baden-Württemberg, Germany, FMG has balanced both of these priorities in each project for many years.
A project completed in early 2019 serves as a good example. At that time, FMG managers needed to develop separate machines that allowed a manufacturer to manually or automatically dispense one- and two-component potting compounds onto electronic parts to encapsulate and protect them from external influences like shock, vibration, moisture, corrosives, impact and extreme temperatures.
“The machines FMG designed are particularly interesting for companies that want to pot more flexibly, but not necessarily faster,” says Martin Baumann, an engineer at FMG. “This is best for manufacturers that need to switch between serial and manual operation for prototype production.”
At the heart of the FMG machines is a customized ViscoDuo-VM mixing system, which is made by ViscoTec Pumpen-u. Dosiertechnik GmbH and features a manual manipulator with a unique potting head. This head precisely mixes and dispenses both components of any standard two-component casting compound.
When needed, buffer tanks and a material degassing system can be installed to degas both compounds and ensure bubble-free potting. Additional accessories include air-drying units, inert gas loading and a circulation line that returns the material to the stirring vessel to avoid fillers sedimentation in the system.
Specially designed for FMG, the manual mixing system can be positioned in any axis with minimal operator effort for easy potting. This is possible because the force of the manipulator’s weight is offset by a rope pull balancer.
The automated version of the FMG machine features a six-axis cobot and a pallet storage system. During operation, the robot retrieves a pallet from storage and moves it into place. The robot then picks up the ViscoTec potting head and moves it along a grid on the pallet to pot a preprogrammed number of electronic parts. Once this is completed, the robot pushes the processed pallet back into storage and retrieves the next pallet to repeat the process.
Another key benefit of the ViscoTec system, according to Baumann, is its compact design allows it to be attached directly to the potting head. This saves FMG money on valves and pipes, and simplifies automation.
Because the ViscoTec system uses a progressive cavity pump, it is pulsation-free and offers 99 percent repeat accuracy. Its adjustable suck-back feature ensures that material stops cleanly and quickly, thereby preventing dripping or product accumulation. System modularity allows for large-scale potting, microdispensing and endless dosing.
Baumann is also impressed with the ViscoTec system’s versatility. For example, it can dispense standard casting compounds (polyurethanes, silicones, epoxies), moisture-sensitive or light-sensitive materials that are cured with UV light, as well as materials having a wide range of viscosities (up to 7 million megapascals) or mixing ratios (from 1-to-1 to 100-to-1).
For more information on manual or automated mixing systems, call 770-422-4281 or visit www.viscotec.de/en/products/dosing.
