Plastics Extrusion - Pipe, Film & Profile worked example

Regrind Blend Rate at 7.2% target or max regrind rate: a worked example

Suppose target or max regrind rate falls to 7.2%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Calculate regrind percentage from regrind pounds and total blend pounds for an extrusion recipe.

The inputs for this scenario

Regrind weight in blend: 400 lb (held at the documented default)
Total blend weight: 5,000 lb (held at the documented default)
Target or max regrind rate: 7.2 % (the input this scenario stresses; the baseline uses 10)

Working through the calculation

The calculation starts from the formula this tool documents: Regrind Blend Rate = regrind weight in blend ÷ total blend weight.
Regrind blend rate works out to 8 % at these inputs, and this is the headline figure for the scenario.
Gap to regrind target works out to -0.8 points at these inputs.
Regrind weight works out to 400 count at these inputs.
Total blend weight works out to 5,000 count at these inputs.

How this compares with the baseline

Against the tool's baseline example, where target or max regrind rate sits at 10% and the headline result is 8 %, this scenario lands almost exactly on the baseline at 8 %.
It computes the percentage of a blend that is regrind by weight and the point gap to your target or maximum allowed rate. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

Regrind blend rate: 8 % (headline result)
Gap to regrind target: -0.8 points
Regrind weight: 400 count
Total blend weight: 5,000 count

Run it with your numbers

To rerun this with your own numbers, open the live Regrind Blend Rate calculator, set target or max regrind rate to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.