Electric Drives: Which One’s Right For Your Process?...

In today’s plastics processing machinery, the motive force powering the press can take several forms and technologies. Traditionally most machines were hydraulically driven, whereby a hydraulic pump driven by a fixed (constant-speed) electric motor powered most of the machines’ processes.  Over time, incremental improvements in efficiency, accuracy, and operating speeds were introduced. In the 1990s, a new technology became available for injection molding machines: The all-electric machine, which utilizes electric servo motors powering gears, racks, and ball screws to drive most of the machine functions.  The all-electric machines feature low noise, high-speed operation, and the freedom from certain issues associated with hydraulics, particularly those related to fluid handling and leaks within processing equipment. For all of the advantages of the all-electric machine, there are limitations, such as those associated with the machine’s capacity (tonnage) as well as increased maintenance requirements for physical components, due to wear on ball screws, belts, and gears.