Peel tests are often used in packaging applications to determine the bond strength of freshness seals commonly found in food and medical packaging. We performed a 90 degree peel test to determine the force required to peel the freshness seal from a can of Pringles Potato Crisps.
The can of crisps was secured to a metal substrate using a fast acting liquid adhesive (custom fixtures can be designed to allow for faster specimen loading). The specimen was then screwed onto an adjustable peel fixture and the seal tip was secured to a vice grip connected to the machine crosshead (make sure to use the adjustment wheel on the peel fixture to center the specimen under the vice grip). Peel fixtures like the one used in this demonstration feature a sliding peel bed that connects to the moving actuator, allowing the specimen to remain in one position through the entire test. The peel fixture used in this demonstration is adjustable, allowing you to perform peel tests at different angle.
We moved the crosshead to peel the seal at a rate of 3 inches per minute. Because the force required to break the seal is larger than the average peel strength, we performed the test for a distance of 3 inches (the total distance required to completely remove the seal) rather than test to failure (which would have ended the test when after the initial seal break).