The actual pressure applied should be higher than the full chamber pressure. During the injection process, the Crate Mould(FURNITUREMOULD) pressure rises sharply and eventually peaks. This peak is the so-called injection pressure. The injection pressure is significantly higher than the full chamber pressure.
The effect of pressure on the pressure: after the cavity is filled with plastic until the gate is completely cooled and closed for a period of time, the plastic in the cavity still needs relatively high-pressure support, ie maintaining pressure, the specific role is:
The amount of material near the gate is replenished and the uncured plastic in the mold cavity is controlled to flow back to the gate material source under residual pressure before the gate condensation is closed.
Prevent parts from shrinking and reduce vacuum bubbles.
Reduce the adhesion or bending deformation caused by excessive injection pressure of parts. Therefore, the holding pressure is usually 50% to 60% of the injection pressure. If the holding pressure or time is too long, the gate may be too large. The cold material on the flow violently hits the part, adding bright spots near the gate and extending the loop without any benefit.