Plastics Extrusion - Pipe, Film & Profile worked example

Line Speed By Wall Thickness at 66% cooling and sizing efficiency: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop cooling and sizing efficiency to 66%, then walk the calculation through step by step. Estimate usable haul-off line speed from produced footage, run minutes, and a wall thickness or cooling efficiency allowance.

The inputs for this scenario

  • Good extruded length: 1,800 ft (held at the documented default)
  • Elapsed run time: 60 min (held at the documented default)
  • Cooling and sizing efficiency: 66 % (the input this scenario stresses; the baseline uses 92)

Working through the calculation

  • The calculation starts from the formula this tool documents: Raw line speed by wall thickness = good extruded length ÷ elapsed run time.
  • Usable line speed works out to 19.8 ft / min at these inputs, and this is the headline figure for the scenario.
  • Calculated line speed before losses works out to 30 ft / min at these inputs.
  • Cooling and sizing efficiency works out to 66 % at these inputs.
  • Elapsed run time works out to 60 min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where cooling and sizing efficiency sits at 92% and the headline result is 27.6 ft / min, this scenario comes in 28.26% below the baseline at 19.8 ft / min.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to cooling and sizing efficiency, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. The efficiency factor is a single lumped derate — it does not model tank length, water temperature, or vacuum level, so it guides rather than replaces a proper cooling calculation.

Results at a glance

  • Usable line speed: 19.8 ft / min (headline result)
  • Calculated line speed before losses: 30 ft / min
  • Cooling and sizing efficiency: 66 %
  • Elapsed run time: 60 min

Run it with your numbers

  • To rerun this with your own numbers, open the live Line Speed By Wall Thickness calculator, set cooling and sizing efficiency to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.