About 30 years ago, Wolfgang Oehm kicked off the efficiency movement in the plastics industry by developing the world’s first heat recovery system for plastic processing machines. Though the response was initially cautious, the focus on improving efficiency has, particularly in recent years, grown into a broad wave of system technology. A key factor driving this acceleration has been—and continues to be—rising energy prices. A wide variety of industry sectors have been swept up in this wave. The result is a multitude of new and, above all, further developments. Innovations have thus emerged in abundance, but widespread practical implementation has not kept pace with the speed of development. One could currently speak of a certain implementation backlog. Furthermore, the steps taken in these areas are smaller, while the scope of work to be addressed has become broader.
In addition to development activities in the new machinery and equipment sector, the existing stock of machinery and equipment has been identified as a field for optimization measures. This is certainly a very worthwhile area, as the existing stock far exceeds the number of new installations. The example of machine optimization using “EtaControl®” technology demonstrates that the results achievable here—for instance, in terms of energy optimization through the use of advanced technology—are very significant. This technology targets hydraulic plastic injection molding machines with a clamping force of more than 2,000 kilonewtons that are older than five years and are used for the production of technical parts. These machines often exhibit relatively high specific energy consumption. At the heart of this technology is controlled oil flow management that automatically and dynamically adapts to the machine’s energy requirements during the cycle and to the specific molded part. In a broad-scale field trial involving a wide variety of molded parts and machine types, power consumption reductions of up to 53 percent were achieved on injection molding machines. On average, the more than 400 machines equipped with this technology to date have achieved an average power savings rate of 36 percent, while maintaining the same cycle time and product quality!
The “EtaControl®” technology is based on a frequency control system newly developed by ONI, which is integrated into the existing control system of the injection molding machine. It does not interfere with the existing machine control system but operates independently. Process information such as signals from potential-free contacts regarding the cycle sequence, currents from the proportional valves, and analog pump signals are tapped from the machine as control parameters. A key advantage of this technology, in addition to significant energy savings, is that the performance of the injection molding machine is not restricted—it remains at 100 percent. A key switch allows the “EtaControl®” power adjustment function to be easily turned on or off while maintaining machine parameters and cycle times. Further benefits of this technology include a significantly reduced connected load, thereby relieving the transformer station; reduced strain on the cooling system, which leads to lower power consumption; and a massive reduction in noise levels, making a significant contribution to improving the working environment. This example clearly demonstrates that significant improvements can be achieved even in existing machinery.
There is therefore an abundance of optimization potential and application areas for modernizing technologies in existing facilities and, of course, in the realm of new machines and systems. Accordingly, there is ample room for innovation. Expectations are simply often too high! Further, faster, higher—yes, but in steps that users can actually handle! In between, we need healthy consolidation phases to gather experience with developments and make detailed improvements. In contrast, an excessive pace of development—ideally with parallel product lines—leaves users feeling confused rather than enthusiastic. What is needed, then, is a healthy mix of dynamic but not overzealous innovation forces and curious users interested in innovation. In this case, the players maintain a balance on the wave of innovation that is attractive and beneficial for everyone involved.
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