Why do servo-driven injection molding machines produce less noise?

In traditional hydraulic presses with fixed-displacement pumps, the motor and pump run at full speed throughout the cycle; excess hydraulic pressure is continuously vented through the relief valve, generating persistent vibration and loud noise.
Hydraulic servo injection molding machines utilize a closed-loop, on-demand oil supply system, delivering power only during specific actions such as mold opening/closing and injection. During cooling and standby phases, the motor operates at low speed or enters a dormant state, significantly reducing noise caused by pressure relief surges.
1. Elimination of continuous relief-related vibration: Excess pressure is not constantly vented through the relief valve, significantly reducing vibration in hydraulic piping;
2. Dynamic load matching: Motor speed adjusts in real-time according to the process stage, avoiding the mechanical noise associated with constant high-speed operation;
3. Lower oil temperature: Hydraulic oil viscosity remains stable and the pump operates smoothly, reducing cavitation and abnormal noise;
4. Minimal hydraulic shock: Pressure changes are gradual, reducing noise caused by resonance in the piping and machine frame.
The machine's operating noise is significantly lower than that of standard hydraulic models, meeting environmental compliance standards for overseas factories and ensuring a more stable production environment.