Standard Test Method for Seal Strength of Flexible Barrier
Materials (Peel Test)

About ASTM-F88

ASTM-F88 is the standard used when performing peel tests on packaging. Peel tests determine ‘seal strength’ of the package, which is defined as the measure of the package seal’s ability to resist separation. Test results are not only related to package integrity, but also to measuring the packaging processes’ ability to produce consistent seals. Peel tests are commonly used for all types of packaging since seal strength is a necessary requirement.

According to the ASTM standard, “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, Technique B, or Technique C) throughout a test series is recommended.”

Fixtures and Techniques

Peel test

Technique A: Unsupported—Each tail of the specimen is secured in opposing grips and the seal remains unsupported while the test is being conducted. This is the method used by our Medical Package Testing (MPT) services.

Technique B: Supported 90° (By Hand)—Each tail of the specimen is secured in opposing grips and the seal remains hand-supported at a 90° perpendicular angle to the tails while the test is being conducted.

Technique C: Supported 180°—The least flexible tail is supported flat against a rigid alignment plate held in one grip. The more flexible tail is folded 180° over the seal and is held in the opposing grip while the test is being conducted.


1.1 This test method covers the measurement of the strength of seals in flexible barrier materials.

1.2 The test may be conducted on seals between a flexible material and a rigid material.

1.3 Seals tested in accordance with this test method may be from any source, laboratory or commercial.

1.4 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.

Join Us at ADLM 2024!

Booth #1153

Let's meet at the show!