High cavitation isn’t always high performance

Growth Madrigal
Aug 25, 2025
2 min read

Last quarter, a procurement head asked us if we could tool a 32-cavity mould for a precision connector program.

Their logic? More cavities = lower cost per part.

Our answer: Not always.

core problems with high cavitation injection moulding - Kamath Plastics

When more cavities multiply your problems

On paper, high cavitation sounds like efficiency. But in practice, the risks add up fast:

Cooling imbalances across cavities cause warpage and inconsistent dimensions.
Longer flow paths increase pressure drops, leading to short shots in certain cavities.
A single defect upstream (gate wear, thermal drift) can compromise the entire tool, not just one cavity.

The result? Instead of more output, you see higher rejection rates, unpredictable cycle times, and scrap costs that erode the savings you were chasing.

The hidden cost of downtime

OEMs often forget that high cavitation tools are harder and slower to validate. Each cavity must be qualified, measured, and proven for repeatability.

When even two cavities are out of spec, the tool can’t ship. Validation cycles stretch from weeks into months.

And once the tool is in production, maintenance downtime multiplies: one worn insert can take 16 cavities offline at once.

Where low-medium cavitation wins

At Kamath Plastics, we advise clients to align cavitation with program maturity and demand forecasts:

Pilot runs: Low cavitation (2–4 cavities) validates design and tooling faster, with tighter controls.
Growth phase: Medium cavitation (8–16 cavities) balances economies of scale with manageable validation.
High-volume, proven programs: Only then does high cavitation tooling justify the complexity and cost.