Rotational Molding worked example
Cooling Cycle Time at 12% cooling time safety allowance: a worked example
What does the result look like when cooling time safety allowance reaches 12%? The full calculation is worked below with real intermediate numbers. Use it when cooling cycle time in rotational molding is being added to next week's schedule and you need an honest hours estimate.
The inputs for this scenario
- Total heat to remove from part: 120 BTU-equivalent units (unchanged)
- Cooling heat removal rate: 12 units / hr (unchanged)
- Cooling time safety allowance: 12 % (raised for this scenario; the documented default is 10)
Working through the calculation
- Applying the documented formula (Base cooling cycle time time = required work รท processing rate) to the inputs above produces each figure below.
- At this operating point the engine returns 11.2 hr for adjusted run time, the number this scenario is built around.
- At this operating point the engine returns 10 hr for base run time.
- At this operating point the engine returns 12 % for allowance applied.
- At this operating point the engine returns 12 pieces / min for process rate.
How this compares with the baseline
- Against the tool's baseline example, where cooling time safety allowance sits at 10% and the headline result is 11 hr, this scenario comes in 1.82% above the baseline at 11.2 hr.
- A figure at this level is achievable when cooling time safety allowance is genuinely sustained, not just peaked for a shift. It assumes a steady cooling rate; real cooling is nonlinear and depends on air/water flow, mold material, and part geometry, so validate demold flatness and dimensions.
Results at a glance
- Adjusted run time: 11.2 hr (headline result)
- Base run time: 10 hr
- Allowance applied: 12 %
- Process rate: 12 pieces / min
Run it with your numbers
- Every input above is editable in the live Cooling Cycle Time calculator, which recalculates instantly and can be shared with the inputs intact.
Last reviewed 2026-05-12.