Package and Product Integrity Blog

ASTM has recently issued a new standard which tests the mechanical seal strength for round cups and bowl containers with flexible peel-able lids.  This test provides measured values for average seal strength, work and maximum seal strength when using a universal tester to separate the entire lid (cover/membrane) from a rigid or semi-rigid round container.

While the standard is specifically for round containers; oval, rectangular and circular containers with single or multiple cavities can be tested.  The test applies to various industries including food, chemical and pharmaceutical.   This test allows manufacturers of these containers to compare adhesives, seal methods and the affects of post sealing treatments such as aging or sterilization.

ASTM F2824 cites ASTM F88 which many of our customers are familiar with.  F88 tests a portion of a seal and provides an actual seal strength picture of the portion of the seal under test.  F2824 tests the entire seal by pulling the lid off at a rate of twelve (12) inches per minute while maintaining a peel angle of 45 degrees throughout the pull.

The 45 degree angle requires the test specimen to move during the test and in some cases requires a custom fixture to hold the container.  DDL is equipped to carry out this test and has several methods to create custom test fixtures for the best test results possible.

“A good example that helps people envision this test is peeling the foil lid off of a yogurt container” says Al Gale, Sales Engineer for DDL’s Product & Material Division.  “When you perform that simple act you can feel that the initial portion of the pull is harder than when you are in the middle of your pull and the pull gets harder again at the end.  This is exactly what our universal test sees and records during the test.”

The recent ASTM F2 Committee meeting was held in a unique location…Prague, Czech Republic, and I was fortunate enough to represent DDL at the meeting. Regardless of the remote location, the meeting included about 18 US representatives and 20 European representatives. All representatives attended the regular meeting of the committee as well as the workshop on “Flexible Barrier Packaging Test Methods as International Standards.”

The meeting agenda included regular subcommittee meetings of the F2 Committee with most of the discussion revolving around dye penetration leak test methods and environmental stressing of packaging. Some of the highlights included: modifying Test Method F1929, developing new standards for dye penetration and discussion on a method for evaluating the quality of seals in plastic cups with heat sealed lids.

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