ISO 2411 covers the coating adhesive strength of coated fabrics. This test is referred to as a “T-peel” test, because as the two adherends are pulled apart, they form the shape of a “T”. Specimens that are 75 mm wide are pulled at a rate of 100 mm/min. Common results are the mid-point value, mean, minimum and maximum peel strength values.
The challenges of testing to this standard are:
- Data rate used to capture peaks and troughs
- Gripping materials of varying thickness
- Eliminating slippage throughout the test
- Data rate used to capture peaks and troughs – Instron’s 5900 series frames enable data capture of up to 2.5 kHz to ensure that all fast changing test events are captured. Too low of a bandwidth may “dull” the system and lead to missed peaks and troughs, resulting in lower average strength values.
- Gripping materials of varying thickness – When testing an adhesive to a thick substrate, standard grips can result in a misaligned specimen. The advanced screw action grips can be adjusted and offset to ensure that the specimen remains centered in the load string.
- Eliminating slippage throughout the test – The advanced screw action grips employ a patented “quick-change” jaw face design which enables operators to easily change jaw faces to accommodate the needs of their materials. For specimens that experience thinning during the test, pneumatic grips can be used to maintain consistent gripping pressure throughout.
It is important to review ISO 2411:2000 in order to fully understand the test setup, procedure, and results requirements.