Electric drives with a difference

Electric drives are commonplace in many of today’s new injection moulding machines. However, not all electric drives are created equal and Sumitomo (SHI) Demag does things differently. Using high torque direct drives, they can achieve lower energy consumption and better performance than a traditional belt driven electrical axis. Yet, there are even more unique ways in which the German-Japanese moulding specialist applies the technology which elevates it above the competition.

UK Managing Director Nigel Flowers explains why their highly dynamic direct drives pack more power and precision. Increasing moulding reliability and repeatability, while simultaneously reducing energy consumption when compared to belt drives, Nigel highlights how the technology also reduces maintenance and unscheduled downtime costs.

Tailored to the exact requirements of injection moulding machines, Sumitomo (SHI) Demag is the only known global engineering firm operating in this sector to design and build its own drive motors in-house. The company even has an R&D centre entirely dedicated to drive development.

Conversely, it’s common practice for injection moulding machine builders and integrators to source their all-electric drives from external OEMs. This makes it more challenging to optimise the drive to support specific injection moulding requirements, source component replacements, exchange or access service support. 

In a best-case scenario, moulders might be able to source and switch out a power or control module. Yet, in most instances sourcing a new complete drive is the reality. Which of course significantly increases the cost.

Being able to source individual replacement boards offers a more sustainable solution valued by customers. Replacement parts are more accessible, with spares held in stock for immediate shipment.

Fewer mechanical moving parts lessens the chance of premature breakdowns. If something does need replacing, rather than switching out the entire drive, Sumitomo (SHI Demag has designed its drive to be modular. Allowing customers to replace the power module that has outted rather than all three. The cost difference is several hundred pounds versus several thousand for a complete drive replacement.

Drawing power only when it is needed, the company’s direct drive delivers higher injection power and a more dynamic response. Direct drive technology is also more energy efficient than conventional belt drive solutions and when compared to hydraulic drives. In many instances achieving energy savings exceeding 70 percent and even faster cycle times.  What’s more kinetic energy can be recovered and reused. For example, while the clamping unit is braking, energy generated can be used for plasticisation. 

“Our proficiency in designing and building injection moulding motors in-house for over 20 years underpins the Group’s precision difference,” notes Nigel. “Being able to draw upon this expertise ensures the best combination of technology and performance tailored to the machine type, sector, application and size.”