Carbon Fiber Prepreg Out-Time Utilization Calculator

Track cumulative ambient exposure against allowable out-time to prevent prepreg degradation and scrappage.

Manufacturer-specified cumulative out-time limit at ambient conditions.
First ambient exposure, e.g., thawing or kitting time.
Second exposure such as layup pause; defaults to 0 if blank.
Third exposure such as inspection delay; defaults to 0 if blank.

Quality-control aid. Verify handling records and material specifications before releasing parts to cure or shipment.

Examples

  • Allowable 500 h, exposures 120 h + 60 h + 35 h ⇒ Total 215.00 h (43.00% utilisation), 285.00 h remaining, status Comfortable.
  • Allowable 200 h, exposures 140 h with other stages blank ⇒ Total 140.00 h (70.00% utilisation), 60.00 h remaining, status Watch list.

FAQ

Do freezer intervals reset the clock?

No. Allowable out-time is cumulative at ambient conditions; returning material to cold storage pauses the clock but does not reverse time already spent warm.

How should I treat multiple rolls?

Track each roll or kit separately because thawing cycles and layup pauses often differ by work order. Summing exposures by roll prevents inadvertent overuse.

What if a stage is unknown?

Leave the field blank or set it to zero, then investigate with traveler logs or time-stamped freezer data. Conservative defaults can be applied manually if documentation is weak.

Additional Information

  • Result unit: hours of ambient exposure plus utilisation percentage against the stated allowance.
  • Blank optional stages default to zero so unrecorded pauses do not inflate utilisation.
  • Status bands flag when exposure exceeds 70%, 90%, or 100% of the allowance to trigger QA actions.

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