Injection Molding worked example

Regrind Percentage with regrind weight blended per shot of 30 g: a worked example

Push regrind weight blended per shot up to 30 g and the picture changes. This example computes every intermediate figure at that operating point. Use this to verify that your regrind blend ratio stays within the resin supplier maximum (typically 15% to 30%) and your internal quality specification.

The inputs for this scenario

  • Regrind weight blended per shot: 30 g (raised for this scenario; the documented default is 12)
  • Total shot weight (virgin plus regrind): 56 g (unchanged)

Working through the calculation

  • Applying the documented formula (Regrind percentage = (Regrind weight / Total shot weight) x 100) to the inputs above produces each figure below.
  • At this operating point the engine returns 53.57 % for rate, the number this scenario is built around.
  • At this operating point the engine returns -53.57 points for gap to target.
  • At this operating point the engine returns 30 count for affected count.
  • At this operating point the engine returns 56 count for total count.

How this compares with the baseline

  • Against the tool's baseline example, where regrind weight blended per shot sits at 12 g and the headline result is 21.43 %, this scenario comes in 150% above the baseline at 53.57 %.
  • It computes the percentage of a shot made up of regrind by dividing regrind weight by total shot weight and multiplying by 100. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Rate: 53.57 % (headline result)
  • Gap to target: -53.57 points
  • Affected count: 30 count
  • Total count: 56 count

Run it with your numbers

  • Every input above is editable in the live Regrind Percentage calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.