Extrusion Line Throughput Calculator

Calculate required extrusion mass flow from final product cross-sectional area, solid density, and line speed.

Formula and method

Required output (kg/h) = final cross-sectional area (mm²) × line speed (m/min) × solid density (g/cm³) × 0.06.

Inputs and units

Obtain final net cross-sectional area from the drawing or CAD section, measured line speed at the product, and solid density for the exact conditioned grade or a validated product mass-per-length record.

Worked example

A 120 mm² profile at 18 m/min and 0.95 g/cm³ requires 123.12 kg/h; nominal mass is 0.114 kg/m.

When to use it

Use before line setup to reconcile product geometry and take-off speed with an extruder, feeder, gear pump, cooling, cutter, and winder capacity plan.

How to interpret the result

The result is the ideal net product flow. Compare it with measured gross output only after separately accounting for edge trim, startup scrap, coextrusion layers, tolerances, and yield.

Assumptions and limitations

The equation assumes a constant final section and density. It does not predict die swell, drawdown, melt pressure, actual extruder capacity, gauge variation, voids, foam expansion, or process stability.

Validation guidance

Cut and weigh a known finished length after conditioning. Compare measured mass per metre with the geometric value, then compare a timed gross output test on the same basis.

FAQ

Should I enter melt density?

No. This calculation converts the final cooled product section to mass per length, so use the appropriate solid-product density or a measured mass per length.

Sources

SPE Extrusion Division: Estimating Flow Rate of a Continuous Sheet Line · SPE Extrusion Division: Planning the Extrusion Line