Rotational Molding worked example

Demold Time at 7.2% sticking and cleanup allowance: a worked example

This worked example runs the demold time numbers for a tougher week than the baseline: 7.2% sticking and cleanup allowance instead of the typical 10%. Demold time is the labor spent at the cool station opening the rotomold, breaking any part-to-tool adhesion, extracting the finished part, and clearing the cavity for the next shot.

The inputs for this scenario

  • Parts to demold this batch: 120 units (held at the documented default)
  • Parts extracted per operator-hour: 12 units / hr (held at the documented default)
  • Sticking and cleanup allowance: 7.2 % (the input this scenario stresses; the baseline uses 10)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base demold time time = required work รท processing rate.
  • Adjusted run time works out to 10.72 hr at these inputs, and this is the headline figure for the scenario.
  • Base run time works out to 10 hr at these inputs.
  • Allowance applied works out to 7.2 % at these inputs.
  • Process rate works out to 12 pieces / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where sticking and cleanup allowance sits at 10% and the headline result is 11 hr, this scenario comes in 2.55% below the baseline at 10.72 hr.
  • Use it when scheduling the cool-and-strip station or costing parts with deep draws, tight releases, or molded-in hardware that slows extraction. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Adjusted run time: 10.72 hr (headline result)
  • Base run time: 10 hr
  • Allowance applied: 7.2 %
  • Process rate: 12 pieces / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Demold Time calculator, set sticking and cleanup allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.