Evaluation on adhesion performance of polyethylene composite tape heat wound on anticorrosion coating of bends

For the adhesion of polyethylene composite tape heat wound on the anticorrosion coating of bends for 3PE straight pipe, the difference of adhesion performance in different positions of bends was systematically studied, and the influence laws of test temperature and hot water immersion aging on adhesion performance degradation of the anticorrosion coating were analyzed. The results show that the adhesion performance of bend coating in different areas varies greatly. With the increase of test temperature, the peel strength between the anticorrosion coating and pipe body decreases gradually, and the peel strength between the layers of heat wound composite tape is slightly lower than that of FBE underlying. Besides,with the increasing of immersion period in hot water at 50 ℃, the adhesion performance between the anticorrosion coating and the pipe is stable with slight fluctuations in the initial stage(0-60 d), and then decreases rapidly(60-120 d). Moreover,suggestions were put forward to improve the undulating anticorrosion surface in the lap zone, the air bubbles trapped in the middle of the anticorrosion coating and the hollowing in the weld zone, etc. Generally, the research results are of great reference significance for the safe service of anticorrosion coating of pipelines.