FINAT Test Method No. 2 (FTM2) Peel Adhesion 90°

FINAT Test Method No. 2 (FTM 2) is used to investigate peel adhesion of laminates through an angle of 90° with a test speed of 300 mm per minute. Predominately used with laminates and packaging materials, it can also be used for coated laminates to investigate adhesion strengths.

FINAT (a abbreviation of the French title: Féderation Internationale des fabricants et transformateurs d'Adhésifs et Thermocollants sur papiers et autres supports) is the European association for the self-adhesive label industry. FTM 2 is commonly used in the packaging industry and to test other laminate materials. Understanding how packaging will hold up under real-world conditions is critical to ensuring that the products they contain reach their end user undamaged. 

System capacity will depend on the strength of the adhesive; however most tests to this standard will fall in the 1 kN and 5 kN capacity range, making this application perfect for a single column frame such as Instron's 34SC or 68SC. This test is performed by using the combination of an upper grip and lower peel fixture. For the upper grip, both pneumatic side action and advanced side action grips are optimal solutions. Both types of grips feature quick-change jaw faces that can be easily changed to accommodate different materials.

Maintaining exactly 90° from substrate to adherend is critical to properly performing this test. Instron's 90° or variable angle peel fixture can maintain precisely 90° by using a low force sliding table that is adjusted throughout the test. The fixture consists of a bearing mounted table, which is linked to the test system via a cable and pulley. As the crosshead is driven in the tensile direction, the cable pulls the table to maintain a constant 90° angle peel, and a dampening coil spring keeps the table from reacting to inertia caused by load peaks and troughs. This fixture is adaptable for both single and dual column frames.

• In practice, the test sample is attached to the test plate by removing the backing material from each strip and placing the material adhesive side down onto a clean test plate using light finger pressure. The specimen is rolled twice in each direction with the standard FINAT test roller to ensure proper contact. The adherend is pulled from the substrate to measure the peel strength, generally presented in an average load divided by the specimen width.

• For peel tests is is critical to use a high data acquisition rate in order to capture all peaks and troughs in the data, ensuring that all test events are represented in the results. Too low of a bandwidth may “dull” the results and lead to artificially low peel strength values. Instron’s 6800 series frames enable a data capture rate of up to 2.5kHz. With Bluehill Universal's Advanced Performance option, data acquisition rate can be increased to 5 kHz.