In this test, the sample (usually in the form of a wire or strip) is wound along a heart rate. For wire samples with a diameter of less than 1mm, it can be wound on a wire rod whose diameter is 3 times the wire diameter; for wire rods with a diameter of more than 1mm, it can be wound on a wire rod with the same diameter as the wire diameter, each wound into 10~15 coils in close proximity. After winding, if the coating does not peel or peel off, it is qualified; otherwise, any peeling, chipping, flaky peeling, etc. are unqualified for bonding. In the test, the length and width of the sample, the bending rate, the uniformity of the bending action, etc. can be standardized for comparison. (Related instruments: adhesion Tester)