Standard Test Method for Mechanical Seal Strength Testing for Round Cups and Bowl Containers with Flexible Peelable Lids
ASTM F2824 specifies parameters for testing the seal strength of packaged goods that are sealed with a flexible, peelable lid. The test method is similar to ASTM F88 for seal strength, however it uses the entire container instead of a small 1x1 inch sample specimen.
This test is run similar to a peel test. The specification suggests a 45 degree peeling angle, however other angles may be used as long as the practiced test method is properly documented and repeated.
The scope of this test is to determine how difficult or easy it is to open food packaging. Most of these seals are made using a heat sealing machine. Often times these automated packaging machines can become misaligned or mistimed and the seal will not adhere properly. There could also be issues with the adhesive that is being used. This is a great, general, all purpose test that requires minimal sample preparation.
Any type of typical round container shape can be used including circular, oval, or rectangular with round edges. The cup or bowl can also have multiple cavities or pockets as well. The test is designed and written in such a way that it is relatively general in terms of sample size and dimension. It is important that the technician correctly record which samples are being used and the exact test method.
A simple pinch grip attached to an articulated chain is perfect for gripping the peelable lid. A 90 degree peel fixture can be used below the sample in order to maintain a 90 degree angle for the entirety of the test.
The Seal Strength for a specific container and lid is given by a few different values. The first is the average peel strength which is usually taken from a middle portion of the data. The Maximum Seal Strength could also be given by the maximum load that is exhibited during the test which usually occurs during the beginning of the procedure.