Flexibility Test of Anti-Fog Coatings Using Cylindrical Bending Tester

After the coating is cured, use scissors to cut the PET film into a 3x3cm sample for the water contact angle and light transmittance haze test; cut the PET film into a l0x30cm sample for the adhesion, coating film flexibility, and wet abrasion resistance test try.

Using the method described in GB/T 6742-2007, test the sample with a cylindrical bending Tester. Put them together on a flat test bench, select a shaft with a suitable diameter and place it on the shaft support ring. Rotate the clamping screw of the test plate clockwise, loosen the clamping block of the test plate, between the bending part and the shaft rod, insert the sample between the two test plate clamping blocks from above, so that the coating to be tested faces away from the shaft bar, clamp the test panel. Let the test plate rest on the mandrel so that the sample is in a vertical position and in contact with the mandrel.

Turn the screw handle counterclockwise so that the sample is simultaneously in contact with the curved part. Bend the sample 180° at a constant speed within 1-2s, and observe the cracking and peeling of the coating on the sample immediately after bending. The test result is pass/fail, and the test is carried out sequentially with shaft rods of different diameters to determine the maximum shaft diameter at which the coating cracks or peels off.