Decoupled Injection Moulding Setup Principles for Technical Parts
Decoupled injection moulding decouples volumetric filling velocity from packing pressure to achieve tight tolerances and repeatable technical part production.
Hydraulic Pressure Limit
Meaning
Maximum operating thresholds for injection moulding cylinders define the safe force available to drive the screw and pack the cavity. The hydraulic pressure limit represents the point where the machine pump can no longer increase pressure without risking damage to seals or hoses. It dictates the maximum injection pressure and holding pressure the moulder can apply to the resin.
This boundary is set by the equipment manufacturer and cannot be exceeded during normal operation.
Equipment Capability
Machine specifications list the peak pressure the hydraulic system can sustain during the injection phase. Reaching the hydraulic pressure limit is common on older machines with lower limits due to pump wear or outdated valve designs. Knowing this ceiling is necessary when designing moulds for high viscosity polymers.
Process Control
Pressures reaching the system cap cause the screw speed to drop unexpectedly. When the process hits the hydraulic pressure limit, the machine cannot maintain the required flow rate, leading to short shots. Operators must monitor the pressure peaks to ensure the process remains within the linear range of the hydraulics.
Safety Margin
Protective relief valves open if the internal pressure spikes above the set limit. Exceeding the hydraulic pressure limit is prevented by this action which avoids catastrophic failure of the metal components or hydraulic lines. Regular calibration of these valves ensures the machine stays within its intended operating envelope.