Servo Motor Injection Molding Machine

Completely electric IMM (Servo motor injection molding machine)

A full-electric injection molding machine is defined by the Plastics Industry Association. They used to be called the SPI. These machines use servo motors for at least three of the main axes. They power clamp movement, injection, and metering/plasticating. Hydraulics can still drive the other three axes. These are: mold height adjustment, ejection, and nozzle touch.

Kinetic-energy recovery systems are a feature of the most efficient machines (KERS). This patented method uses servo motors as generators. It collects all the energy lost during deceleration on each axis. Then, it transforms the energy back into electricity. The machine then uses the energy again. It uses it for control or heating.

Blended IMM

Hybrid injection molding machines have at least one electric-driven axis. They also have one or more of the three major axes powered by hydraulics. A typical illustration of this is a hydraulic device that has servo-driven metering. The largest energy consumer on any IMM, aside from barrel heating, is the metering. Consequently, it makes sense to meter using at least a servo-electric drive. Every movement on a servo-driven pump uses hydraulics. So, hybrid machines are not the same as machines with servo drives.

Servo hydraulic IMM that is driven

"Injection Molding Machine Manufacturer" call it an IMM. It is fully hydraulic and has a servo motor to power the hydraulic pump. They call it a servo-hydraulic machine. These devices typically have a fixed pump. But, they may also have variable pumps with swash plates (often DFEE or DFEC).

Typical hydraulic IMM with a pump with variable displacement

These machines have a variable displacement pump. It has a swash plate that the control can alter. This adjusts the pump's oil flow to match the hydraulic system's demand. The motor operates at a constant speed. The pumps will continue to run inactively and waste energy if the machine is stationary.

Energy effectiveness

This is unsurprising. Servo-driven pump systems are also known as servo-pump systems. They are much more energy efficient. This is true compared to systems that use a variable-displacement pump. They have a constant-speed motor. What then is the purpose of a servo pump? The pump machine has a servo-driven motor. It only turns when the hydraulics need oil.

Long cooling time

There is no pump movement and hence no energy consumption by the pump while no axis is in operation. The amount of energy saved varies greatly. It depends on the specific process point of the application. In contrast, an application with a long cooling time has a motor that would idle for seconds or minutes. But, a fast-cycling packaging application will have a smaller energy savings percentage.

Electric energy can't become hydraulic pressure. It also can't turn back into kinetic energy. So, full-electric machines have the highest energy efficiency. They turn electric energy directly into kinetic energy.

The following would be a very rough classification

Servo motor injection molding machines use 65% to 70% as much energy. Full-electric machines use 45% to 60% as much. Hydraulic machines with constant speed motors use 100%. Hybrid machines with only metering fully electric use 75% to 80%.