ASTM F88 Seal Strength Testing of Flexible Barrier Materials

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ASTM F88 Seal Strength Testing for Flexible Barrier Materials
ASTM F88 Seal Strength Testing of Flexible Barrier Materials

The ASTM F88 standard describes the test procedure for measuring the maximum seal strength of flexible barrier materials. These materials are often used in medical packaging. Sterilization is a major part of the medical device manufacturing industry. Therefore, manufacturers take care to produce properly sealed medical packaging. One way to test the quality of seal strength on packaging is through testing methods in ASTM F88.

Our engineers are familiar with the ASTM F88 test procedure and can guide you through the process and help you choose the best equipment.

What Is ASTM F88?

ASTM F88 is a testing standard for measurement of seal strength for flexible barrier materials in medical packaging. Seal strength is not only relevant to opening force and package integrity, but for measuring the packaging processes. It is common for confusion to arise regarding the difference between package seal strength and package integrity. Seal strength relates to the force required to separate two flexible components of the package. This can be measured through a peel test using a peel tester. Alone, this does not prove the integrity of the entire package, only the integrity of the seal strength of two components. Although further testing of the entire package may be necessary, the main cause for failing package strength tends to be through the seal.

How to Perform ASTM F88?

Cut a one inch wide strip of the seal from each of the 4 sides of the package with a sample cutter. Clamp each leg of the test specimen in a Peel Tester. Align the more rigid side of the sample to be clamped in the top grip. The seal should be tested at a rate of grip separation of 200 to 300 mm/min. (8 to 12 in./min). For each cycle, report the maximum force as the specimen is stressed to failure and identify the type of failure.

Important Considerations When Testing per ASTM F88

In ASTM F88 it is useful to know that Figure 1 describes three configurations for the test, but there are only two in reality. The two configurations are T-Peel where both adherends are flexible (let’s say with Tyvek and polyurethane), and a 180 degree peel where one adherend is flexible and the other is rigid (such as a thermoform PET tray).

Also, our engineers recommend pneumatic grips for ASTM F88 because the specimen ends must be aligned such that the peel interface is accurately perpendicular to the load center of the peel test machine. This accurate alignment is easier to achieve with pneumatic grips than with mechanical grips because mechanical grips must be twisted to tighten.

ASTM F88 Test Equipment

Get the Best Value Seal Strength Testing Equipment!

A 100 family test machine is recommended for ASTM F88. The 100-250 test machine consists of a 1100 N (250 lbf) vertical load frame, an electromechanical actuator, load cell, a test controller, test software and choice of peel grips. Our load cells measure loads accurately (+/- 0.5% of reading) from full scale rating to 1% of FS. A 10 lb load cell can be calibrated to measure 0.5 N (0.1 lb) to an accuracy of 0.0005 lb. Our load cells measure loads accurately (+/- 0.5% of reading) from full scale rating to 1% of FS.

ASTM F88 Peel Grips & Accessories

In order to get the best results from your peel testing, grips are an essential part of your purchase. The G240k or G227 are the best manual vice grips for ASTM F88. These are a lower cost option and produce great results. You may also consider purchasing pneumatic grips.

Pneumatic grips are helpful in getting the specimen well-aligned in the grips due to the foot activator giving you both hands free to hold the specimen. It is not easy to hold the specimen exactly perpendicular in the grips while you are cranking a manual vice grip. We offer specially configured ASTM F88 Pneumatic Grips for testing package seal strength. 

ASTM F88 Seal Strength Test Machine

Seal strength testers, or peel test machines, are universal test machines specially configured to determine the adhesive seal strength or the strength of the adhesive bond between two materials.

If you're looking to perform ASTM F88, give us a call and one of our engineers will help guide you through the ASTM F88 test process and help you choose the best test system configuration for your requirements.