The Lab · Rheology

Cavity Balance

Run a short shot, weigh each cavity, enter the weights. The tool reports how far out of balance the tool is filling and which cavities lead and lag.

Short-shot weights
Material
Melt °C
Mold °C
Fill %
Cavity 1 (g)
Cavity 2 (g)
Cavity 3 (g)
Cavity 4 (g)
Enter all four cavity weights to compute imbalance.

How to run this study

Measure how uniformly a multi-cavity mold fills by comparing part weights from each cavity on a short shot. This exposes cavity-to-cavity variation and tells you whether the runner or process needs attention.

Procedure

  1. 01Set injection velocity to the optimal value from the viscosity-curve study. Disable pack/hold.
  2. 02Label each cavity so parts trace back to where they came from.
  3. 03Reduce shot size / transfer position to a short shot around 95% fill.
  4. 04Mold 5 shots to stabilize, then collect one part from each cavity and weigh them.
  5. 05Enter the fill % and each cavity weight — the tool reports imbalance and which cavities lead and lag.
  6. 06For a fuller picture, repeat at several fill levels (e.g. 20/40/60/80/95%) and compare the trend.