What are the advantages of fixed pump injection molding machines?

Compared with servo-driven pump machines, fixed pump Injection Molding Machines are less expensive. They also require less electricity to operate. Servo-driven pumps are available in vane or internal gear designs. They are popular for their high system pressures and volumetric efficiency. They perform very efficiently when coupled with a VFD motor.

Fixed pump Injection Molding Machines have a hydraulic unit that consists of control valves, an oil pump and a motor. The hydraulic unit ensures the stability of the machine and ensures accurate operations. It also ensures the safety of the injection unit by preventing leaks.

The hydraulic unit can be a hydraulic oil type or a fixed displacement pump. In the case of a hydraulic oil type IMM, the pump needs to be coupled to the main electric motor. In the case of a fixed displacement pump, the oil is pumped to the full capacity of the machine. The oil pump also maintains pressure in the hydraulic system. Hence, the machine is efficient and stable.

The hydraulic system of an injection molding machine also works the same way as the whole machine. The hydraulic system has power matching features, ensuring efficient operation of the machine. During the final cooling stages of an injection molding machine, the VFD slows down the rotation of the pump. This prevents excessive heat production from the pump, thereby saving input energy to the molding machine. The VFD also compensates for internal system leakages.