Release force of release film testing standards.

Trial scope: This method is used to test the permanent adhesion or peelability of release films

Definition: The release film peeling force is the force required to peel a pressure-sensitive material from a standard test plate at a certain angle and speed under certain conditions. It is tested after 20 minutes and 24 hours of bonding between the pressure-sensitive material and the standard test plate, and the latter is called the permanent peeling force.

Test instrument: A tensile tester or similar instrument, with a fixture capable of peeling pressure-sensitive materials at 180 °, a release film peeling speed of 300mm/min, and an accuracy of+2%. The test plate is made of glass or stainless steel with a smooth surface. A standard pressure roller (2KG).

Test sample: It should be a test strip taken from representative materials, with a width of 25mm and a length of at least 200mm along the instrument direction. The cut should be clean and straight, and at least 3 pieces of each material should be taken for testing. The test tape should be TESA7475.

Test conditions: temperature 23 ℃± 2 ℃, 50% RH ± 5% RH.

Test steps: Place the TESA7475 adhesive surface downwards and lightly press the adhesive strip onto the clean test board. Use a pressure roller to press back and forth at a speed of approximately 10mm/second twice, making the adhesive surface in close contact with the test board. (The release film needs to be pulled or fixed on the test board.) After the test strip is applied properly, it should be left for 20 minutes before testing. If permanent peeling force needs to be tested, it needs to be left for 24 hours. Debug the stripping angle to 180 °, set the speed to 300mm/min, and run the test on startup.

Test results: The peeling force is expressed in N/25MM (1KG=9.81N), and the average value is taken for each test strip. The bonding time is 20 minutes or 24 hours.