Rotational Molding worked example

Pigment/Additive Usage at 61% dry-blend transfer efficiency: a worked example

This worked example runs the pigment/additive usage numbers for a tougher week than the baseline: 61% dry-blend transfer efficiency instead of the typical 85%. Pigment and additive usage tells a rotational molder how much colorant, UV stabilizer, or antioxidant masterbatch actually has to be weighed out per batch, not just the theoretical loading rate on the spec sheet.

The inputs for this scenario

  • Total part surface area or shot weight covered: 500 units (held at the documented default)
  • Pigment/additive loading per unit of resin: 0.08 units (held at the documented default)
  • Dry-blend transfer efficiency: 61 % (the input this scenario stresses; the baseline uses 85)

Working through the calculation

  • The calculation starts from the formula this tool documents: Required pigment/additive usage = covered amount × use per unit ÷ transfer efficiency.
  • Required quantity works out to 65.57 units at these inputs, and this is the headline figure for the scenario.
  • Theoretical amount works out to 40 units at these inputs.
  • Loss allowance works out to 25.57 units at these inputs.
  • Efficiency works out to 61 % at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where dry-blend transfer efficiency sits at 85% and the headline result is 47.06 units, this scenario comes in 39.34% above the baseline at 65.57 units.
  • Use it when quoting a new colored part, ordering masterbatch for a run, or reconciling why your color usage runs higher than the loading rate suggests. 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

  • Required quantity: 65.57 units (headline result)
  • Theoretical amount: 40 units
  • Loss allowance: 25.57 units
  • Efficiency: 61 %

Run it with your numbers

  • To rerun this with your own numbers, open the live Pigment/Additive Usage calculator, set dry-blend transfer efficiency to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.