The Lab · Process

Cooling Time

Measure one dimension across a range of cooling times. The tool finds where it stops moving, adds a margin, and shows the cycle seconds that come off — usually the cheapest cycle-time reduction on the machine.

Cooling-time series
Material
Melt °C
Mold °C
Cooling time (s)Dimension (mm)
Drawing tolerance (total band)

Enter at least two cooling-time / dimension points to find the minimum.

  • Each row is one cooling time, with hold time fixed at the value gate seal found.
  • Measure the same feature on every part, after it has stabilised at room temperature.
  • Keep lengthening cooling until the dimension stops moving.
  • Add the drawing tolerance to tighten what counts as stopped.
Predicted · not measuredCooling time from heat conduction

How long a wall of this thickness takes to conduct its heat into the mold, from the classical slab solution. It assumes a mold face held exactly at the mold temperature and one uniform wall — a boss or rib cools slower — and counts from the end of fill, so hold time is inside it. Set it beside the measured settle point: the measurement is the answer, this says whether it is in the right neighbourhood.

Part and material

Enter melt and mold °C in the study conditions above.

How to run this study

Find the shortest cooling time at which a dimension has stopped changing. Cooling is usually the largest block of the cycle, so this is often the cheapest cycle-time reduction available — and running below it makes dimensions follow the cycle rather than the process.

Procedure

  1. 01Start at a cooling time you are confident is longer than needed.
  2. 02Mold five shots to stabilise, then measure the same dimension on the last three and record the average. Measure at a consistent time after ejection — the part keeps moving.
  3. 03Reduce cooling time by a fixed increment and repeat.
  4. 04Continue down until the dimension starts changing between settings, then a little further.
  5. 05Enter each cooling-time / dimension pair. The tool finds where the dimension stops moving and adds an increment for margin.
  6. 06Enter the drawing tolerance if you have one — it tightens what counts as "stopped moving".