Building Materials Manufacturing worked example

Glass Annealing Time at 14% soak, cooling, and handling allowance: a worked example

What does the result look like when soak, cooling, and handling allowance reaches 14%? The full calculation is worked below with real intermediate numbers. a glass plant needs to reserve annealing or controlled cooling time before cutting, packing, or shipment

The inputs for this scenario

  • Glass load requiring annealing: 1,200 tons (unchanged)
  • Annealing lehr or cycle release rate: 150 tons / hr (unchanged)
  • Soak, cooling, and handling allowance: 14 % (raised for this scenario; the documented default is 12)

Working through the calculation

  • Applying the documented formula (Base glass annealing time = glass load requiring annealing รท annealing lehr or cycle release rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 9.12 hr annealing time for glass annealing time, the number this scenario is built around.
  • At this operating point the engine returns 8 hr annealing time for base glass annealing time.
  • At this operating point the engine returns 14 % for soak, cooling, and handling allowance.
  • At this operating point the engine returns 150 pieces / min for annealing lehr or cycle release rate.

How this compares with the baseline

  • Against the tool's baseline example, where soak, cooling, and handling allowance sits at 12% and the headline result is 8.96 hr annealing time, this scenario comes in 1.79% above the baseline at 9.12 hr annealing time.
  • A figure at this level is achievable when soak, cooling, and handling allowance is genuinely sustained, not just peaked for a shift. It assumes a single steady release rate and a flat allowance; it does not model glass thickness, composition, or strain-point differences that change the required cooling curve for specific products.

Results at a glance

  • Glass Annealing Time: 9.12 hr annealing time (headline result)
  • Base glass annealing time: 8 hr annealing time
  • Soak, cooling, and handling allowance: 14 %
  • Annealing lehr or cycle release rate: 150 pieces / min

Run it with your numbers

  • Every input above is editable in the live Glass Annealing Time calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.