Measure twice. Slice once.

Filament recycling

Filament Extrusion Rate Calculator

Convert a cooled filament diameter and linear haul-off speed into the mass rate that reaches the winder.

Inputs

Use cooled, measured filament diameter.
Use a documented or measured value for the actual blend.
Measure the finished strand after cooling.

What this tool calculates

Convert a cooled filament diameter and linear haul-off speed into the mass rate that reaches the winder.

Formula and method

Cross-sectional area = πd² ÷ 4. Volume rate = area × line speed. Mass rate = volume rate × solid density. Batch time = planned mass ÷ mass rate.

When to use it

Use this to compare a measured line speed with expected mass output, estimate run time, or spot a mismatch between weighed output and nominal diameter.

Worked example

At 1.75 mm, 1.24 g/cm³, and 2 m/min, the theoretical output is about 5.97 g/min or 0.358 kg/h. One kilogram takes about 2.79 hours at that steady rate.

Assumptions and limitations

The strand is solid, round, at the entered cooled diameter, and the line speed is steady. Density is for the finished blend. Die swell, voids, moisture bubbles, changing diameter, startup losses, and downtime make real output differ. Compare with a timed weigh test.

Common mistake

Do not use hot die-exit diameter; the mass-rate calculation belongs to the cooled filament that will be accepted and wound.

Continue the recycling workflow