Thermoforming & Vacuum Formed Products worked example

Plug-Assist Speed at 65% line efficiency: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop line efficiency to 65%, then walk the calculation through step by step. Plug-assist speed measures how fast the plug pre-stretches heated sheet into the mold cavity before vacuum draws it home, and it is the single biggest lever on wall-thickness distribution in deep-draw thermoformed parts like cups, trays, and clamshells.

The inputs for this scenario

  • Formed parts completed this run: 1,200 units (held at the documented default)
  • Plug-assist forming runtime: 8 hr (held at the documented default)
  • Line efficiency (uptime x quality): 65 % (the input this scenario stresses; the baseline uses 90)

Working through the calculation

  • The calculation starts from the formula this tool documents: Raw plug-assist speed = completed output ÷ runtime.
  • Effective throughput works out to 97.5 ft / min at these inputs, and this is the headline figure for the scenario.
  • Raw throughput works out to 150 ft / min at these inputs.
  • Efficiency works out to 65 % at these inputs.
  • Runtime works out to 8 hr at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where line efficiency sits at 90% and the headline result is 135 ft / min, this scenario comes in 27.78% below the baseline at 97.5 ft / min.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to line efficiency, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It is a throughput average — it will not tell you whether the plug speed itself caused thin corners; only a wall-thickness map or gauge scan does that.

Results at a glance

  • Effective throughput: 97.5 ft / min (headline result)
  • Raw throughput: 150 ft / min
  • Efficiency: 65 %
  • Runtime: 8 hr

Run it with your numbers

  • To rerun this with your own numbers, open the live Plug-Assist Speed calculator, set line efficiency to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.