Adhesion performance test is in accordance with the national standard GB/T 13448-2006 "Color-coated steel plate and steel strip test method" requirements of the bending test method, do 180 ° bending test. The instrument is a QZW T-bend testing machine. After the sample is bent 180° around its edge, the minimum number of pads (thickness is the same as the original plate) that the coating does not cause tape peeling and cracks is recorded as n T (such as 0T, 1T, 2T, 3T), and is evaluated according to the value of n The ability of the coating to resist cracking or falling off when the color-coated plate is bent.
In fact, the T-bend value without tape peeling and the T-bend value without cracks are different in value. Usually, the T-bend value without cracks is larger than the T-bend value without tape peeling. Therefore, there are two T-bend representations, which are named "tape peeling T-bend value" and "crack-free T-bend value" according to different observation standards. If there is no special instruction, the crack-free T-bend value is usually used to measure adhesion. That is, the crack-free T-bend value is referred to as the T-bend value.
