This test method measures the force required to separate a test strip of material containing the seal. It also identifies the mode of specimen failure.
PEEL STRENGTH TEST
PEEL / TENSILE STRENGTH TEST
Seal strength is a quantitative measure for use in process validation, process control, and capability. Seal strength is not only relevant to opening force and package integrity, but to measuring the packaging processes’ ability to produce consistent seals. Seal strength at some minimum level is a necessary package requirement, and at times it is desirable to limit the strength of the seal to facilitate opening.
The maximum seal force is important information, but for some applications, average force to open the seal may be useful, and in those cases also should be reported. A portion of the force measured when testing materials may be a bending component and not seal strength alone. A number of fixtures and techniques have been devised to hold samples at various angles to the pull direction to control this bending force. Because the effect of each of these on test results is varied, consistent use of one technique (Technique A: Unsupported, Technique B: Supported 90 deg, or Technique C: Supported 180 deg) throughout a test series is recommended.