Decoupled II

Pressure Transition

Cavity pressure measurement determines the exact moment when the machine switches from velocity control to pressure control. When the molten polymer reaches the transducer tip, the rising force signals the machine controller to alter screw action. This feedback loop ensures that the cavity receives a consistent volume of resin even if the viscosity of the raw material varies between batches.

The result is a highly repeatable part weight and reduced warp.

Tooling Requirement

Specialized instrumentation must be installed in the mould plates to support this configuration. Piezoelectric or quartz transducers are positioned behind ejector pins or directly in the cavity wall to read the polymer pressure. Although this adds to the tooling cost, it reduces the scrap rate of expensive technical parts.

Melt Behaviour

Volumetric shrinkage is controlled more precisely because the pack phase starts at the exact same state of cavity fill. Fluctuations in the melt temperature or regrind percentage alter the flow resistance, but the switchover adapts automatically to these shifts. This prevents both short shots and flashing in the cavities.