Meaning
Injection molding machines rely on a precise transition point from high-velocity filling to pressure-controlled packing. This transition is accomplished through cavity pressure switchover, which triggers the change in machine behavior when a sensor in the mold cavity registers a pre-set pressure threshold. It prevents the mold from overfilling, safeguarding against flash and tool damage during high-volume production.
Process Transition
Relying solely on screw position for the shift can cause part weight variations if the melt density fluctuates. The use of cavity pressure switchover ensures that the transition occurs at the same state of mold fill, regardless of viscosity shifts in the polymer batch. Melt temperature variations are compensated automatically by this closed-loop control method.
Quality Impact
Parts produced with inconsistent packing pressures exhibit dimensional instability and warpage. Molding shops utilize cavity pressure switchover to narrow the statistical spread of part weights, which directly reduces scrap rates during long production runs. Unstable processes that lack this control run the risk of generating short shots or flashed parts.
Financial Outcome
Reducing scrap directly affects the profitability of high-volume runs. Tooling wear is minimized when the transition pressure is kept below the yield limit of the steel mold, extending the useful lifetime of the injection tool. This reduces maintenance costs and downtime.
