On most shop floors today, electric injection molding machines are becoming the norm, surpassing hydraulic machines, which long have been the most popular choice.
All-electric presses generally are rarely more than 700 tons, with 500 tons usually being the upper end. The machines today are more robust.
The electrification of injection molding machinery has happened at differing rates around the globe. The trend started two decades ago with Asian machinery manufacturers. European manufacturers joined the fray later.
In North America, about half of the units sold today are electric. That trend has been stable over the last decade. The smaller the machinery, the higher the percentage that are electric.
The cost of an electric injection molding press generally is about 20 percent more than a comparable hydraulic unit, though increased demand for smaller molds continues to narrow the cost gap. As a result, a growing number of injection molding shops are switching to electric presses to gain efficiencies and gain a competitive edge.
Leading companies tout all-electric options that offer fast acceleration of injection speed.
There are myriad applications for standard hydraulic and hybrid injection molding machines. However, several machine manufacturers are primarily focused on the manufacturing of all-electric machines. This trend also is driving advancements in technology. Larger tonnage electric molding machines, which once were too expensive to build, are becoming more common.
There are several reasons many shops are adding electric machines or even switching to an all-electric machine lineup.
Electric machines are cleaner, with no hydraulic oil, leaks or spills on the shop floor.
The clean and quiet working environment that you get with all electric injection molding machines make them a perfect option to use for food packaging and medical molders.
Electric machines also are energy efficient. When comparing running the same part and mold on a hydraulic machine versus an all-electric press, a shop can expect to see energy savings from 50% to 70% in most applications.
Many injection molders are operating electric machinery with updated software and internal communication systems that more easily facilitate increasing Industry 4.0 initiatives through auxiliary equipment such as mold temperature controllers, dryers, downstream automation, and packaging.
The electric machines also offer high repeatability and precision with closed-loop controls and linear motions. They also are extremely reliable.
Electric presses also do not have sticking valve issues, degrading oil issues, ambient temperature process fluctuations and noisy pumps.
While electric machines may one day be offered in larger tonnages, it would require changes that aren’t in place now. It is clear that all-electric injection molding machines will continue to be a popular option for many shops.