What Is the ASTM F88 Peel Testing System Used For?

The ASTM F88 peel testing system is used to measure the seal strength of flexible packaging by pulling a sealed seam apart at a controlled angle and speed. It applies to pouches, sachets, lidding film, and other heat-sealed or adhesive-sealed packages, and it is most common in medical device packaging, food packaging, and pharmaceutical packaging, where the force needed to open a seal is both a quality and a safety characteristic. If your product is a flexible package with a peelable seal and you need a repeatable number for seal integrity, this is the test type you are looking for.

What ASTM F88 actually measures

ASTM F88 is the standard test method for seal strength of flexible barrier materials. In practice, a specimen is cut so that the two sealed layers can be separated, the unsealed tails are clamped in the grips of a force tester, and the seal is peeled apart at a specified angle (commonly around 90° or 180°, depending on the fixture and specimen) and a constant rate.

The tester records the force throughout the peel. Results are usually reported as:

• Peak force — the highest force reached during the peel, often the force to initiate seal separation.
• Average force — the mean force across the peeled length, useful for describing steady peel behavior.
• Force per unit width — force normalized to the specimen width, which makes results comparable between samples of different sizes.

Because seals rarely peel at a perfectly constant force, the shape of the force curve matters as much as the single number. A seal that peaks high and then drops sharply behaves differently from one that peels steadily.

What the system is made of

A working ASTM F88 setup is not just a force gauge. It generally combines:

C.S.C. Force Measurement, Inc. supplies force and torque systems from brands including Mark-10, Chatillon, Lloyd Instruments, and Mecmesin, and lists an ASTM F88 Peel Testing System among its featured products. That means the peel system is assembled from a tester plus the appropriate grips and fixtures rather than being a single fixed instrument.

Typical test flow

1. Prepare the specimen. Cut a strip across the seal so both sealed and unsealed portions are exposed, following the width and conditioning requirements of your test plan.
2. Load the specimen. Clamp the unsealed tails in the grips so the seal sits between them and the peel angle is correct.
3. Set the test parameters. Choose the crosshead speed and the data sampling rate; the standard specifies a rate, and your internal procedure may narrow it further.
4. Run the peel. The tester separates the seal and records force versus extension.
5. Review the curve. Identify peak and average force, note any spikes or plateaus, and compare against your specification.
6. Report. Record the result with the specimen width, speed, and peel angle so the number is reproducible.

Industries and applications

• Medical device packaging — sterile barrier pouches and trays where seal strength affects sterility maintenance and ease of aseptic presentation.
• Food packaging — snack bags, retort pouches, and lidding where seals must survive handling but still open cleanly.
• Pharmaceutical and healthcare — blister and pouch seals where consistent opening force is part of the user experience.
• Consumer and industrial flexible packaging — any heat-sealed or adhesive-sealed package with a peelable seam.

The common thread is a package that is opened by peeling rather than tearing or cutting, and a manufacturer that needs a defensible, repeatable seal-strength value.

What to confirm before buying or configuring

• The exact standard revision and method your customer or regulator expects, since peel angle, speed, and specimen geometry are specified there.
• Grip and fixture compatibility with your specimen width and seal orientation — a fixture that fits one pouch format may not fit another.
• Load cell range matched to the forces your seals actually produce, so you are not measuring near the bottom of the range.
• Software reporting that outputs peak, average, and force per unit width in the units your quality system uses.
• Calibration and service — C.S.C. states it provides ISO 17025 calibration services and factory-trained technicians who can perform preventive maintenance and repairs, which matters if the system will be part of an audited quality process.

If you already know your seal type, specimen width, and expected force range, the remaining decision is mostly about which tester and fixture combination fits your throughput and budget. If you are still defining the test, start by confirming the standard revision and the peel angle your application requires, because those two choices drive the fixture selection more than anything else.