Nothing relative about efficiency of drive controls
MACHINING & MACHINERY DRIVING EFFICIENCY
SUMITOMO DEMAG
Nothing relative about efficiency of drive controls
By Kris Thacker, Technical Sales Manager, Sumitomo( SHI) Demag
It is widely accepted that drive controls play a pivotal role in injection moulding machines. However, there remains some ambiguity about how significantly they influence overall performance. Kris Thacker, Technical Sales Manager, Sumitomo( SHI) Demag clarifies that drive controls are unquestionably fundamental to the machine’ s operational capabilities.
Over the years, drive technology has seen incremental improvements, leading to variations in performance across different models. Some drives are designed to achieve faster acceleration and enable quicker braking, enhancing productivity and cycle times. Others are engineered with a focus on energy efficiency, helping processors reduce power consumption and operational costs.
Ultimately, the choice of drive control can shape not only the speed and responsiveness of the machine, but also its energy profile and suitability for specific moulding applications. As drive technologies continue to evolve, understanding these distinctions becomes essential for optimising both performance and efficiency in injection moulding operations.
Tracking the evolution of efficiency
Controlling the injection pressure and process optimisation is essential for mouldability as this precise motion control is what the drive achieves. Much like a gearbox, the drive in every injection moulding machine transforms the rotational speed into a linear movement. The science is the same for all drives
Kris Thacker explains why drive controls are fundamental to the operational capabilities of injection moulding machines.
across the ages, whether it is hybrid, variable frequency, electric servos, electric belt, direct drives or allelectric drives.
The choice of drive in injection moulding used to be application dependent as the requirements for sector and processing applications need to factor in so many varying aspects. This included holding patterns, rapid changes in acceleration and deceleration, cooling times and component removal.
With the arrival of mass production and trade globalisation, the 1980s and 1990s machine hierarchy was characterised by widespread adoption of hydraulic drives. These were hydraulic fixed displacement or hydraulic variable displacement drives, and featured a motor, pump, valve and hydromotor. The fact many mould shops continue to use these machines is testament to their robustness and longevity.
However, a score of 0.46 for relative efficiency in today’ s manufacturing climate is not great. It means that more than half of the input energy is being wasted. This could be improved by optimising processing parameters. Yet, given the elevated energy costs, a relative efficiency rating of 0.46 strongly suggests that your current machine may have reached a point of significant inefficiency.
Switching to a model with an allelectric belt drive or direct drive will reduce cycle time, save energy and improve moulding precision and part quality. Resulting in long-term operational savings.
Sitting between all-electric and hydraulics are servo hydraulic systems. These provide a highperformance and more energyefficient alternative, while retaining the benefits of hydraulic force. Often achieving a relative efficiency rating of over 0.85, these moulding machines use a variable speed drive motor to drive either a fixed or variable displacement pump.
Found predominantly in advanced manufacturing, robotics, automotive and aerospace, the servo hydraulic market still supports manufacturers. Now, the focus is on the next generation of servo motors. These will be powered by drives that combine the power density of hydraulics with the precision, control, energy efficiency and smart connectivity of electric drives.
Optimised electric efficiency
At 0.92 relative efficiency, high torque electric direct drives represent the most consistent efficiency benchmark. Some of the
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