Plastic film · Laboratory data reduction
Flexible Package Seal Strength Calculator
Normalize maximum and average flexible-package peel force to N/mm and the common N/15 mm reporting basis.
Formula and method
Seal strength (N/mm) = peel force (N) ÷ specimen width (mm). N/15 mm result = seal strength (N/mm) × 15 mm.
Inputs and units
Enter the measured specimen width, maximum peel force, and the average force for the defined region of the seal trace. Keep sealing conditions, specimen orientation, test technique, unsupported tail length, separation rate, conditioning, and failure mode with the result.
Worked example
A 15 mm specimen with 8.4 N maximum and 6.6 N average force gives 8.4 N/15 mm peak and 6.6 N/15 mm average seal strength.
When to use it
Use after a flexible-package seal pull to normalize differently cut specimen widths or to verify laboratory/exported spreadsheet arithmetic.
How to interpret the result
Peak and average values are not interchangeable. Pair the normalized number with the failure mode because peel, cohesive rupture, material tear, elongation, and grip effects can produce different meaning.
Assumptions and limitations
Normalization does not make different test techniques or materials equivalent. The tool does not select a seal-window target, remove machine dynamics, identify seal leaks, or approve package integrity.
Validation guidance
Measure the actual cut width, confirm force units and the averaging region, review the curve and failure mode, preserve every valid replicate, and follow the current governing procedure for specimen preparation and reporting.
FAQ
Why show both N/mm and N/15 mm?
N/mm is a direct width normalization; N/15 mm is common in flexible-packaging records. Keeping both makes conversions explicit without changing the underlying force trace.