Patched heat shrink sleeves or cable repair sheets are the most commonly used patched anti-corrosion products, but some problems cannot be avoided, such as the warping of the edges of heat shrink sleeves. Generally, this problem is caused by the following two factors.

     1. The width of the solvent-free epoxy primer on the surface of the steel pipe is not enough, or the primer is not applied at both ends. As a result, the edges of the heat shrink sleeve are not well adhered.

     2. It may be that the baking is not uniform, and the two ends of the heat shrink sleeve are not heated well, resulting in incomplete shrinkage on the steel pipe, so that the surface of the steel pipe cannot be bonded well. The baking is uniform, the heating is uneven, and the hot melt adhesive on the inner surface of the heat shrink sleeve is not completely melted. This situation is relatively common. Because many construction workers use it for the first time, they do not know how long it takes to complete the heating. Therefore, they often stop heating without heating in place.

      Solution: In the above two cases, first of all, we should try to paint the epoxy primer on the surface of the steel pipe as thin as possible. The width of the painting can appropriately exceed the width of the heat shrink sleeve. The heat shrink sleeve shrinks back and is not as wide as before, but we still recommend painting it a little wider. Another point is that when we heat-shrink the heat-shrinkable sleeve, we must fully bake it from the middle to the two ends, and heat it evenly until the glue on both ends of the heat-shrinkable sleeve evenly overflows.

热缩套边缘翘起的原因

   补口热缩套或者电缆修补片，是最为常用的补口防腐产品，但是也避免不了一些问题，比如热缩套边缘的翘起。一般形成这个问题的主要有下面两个因素导致。

    1，无溶剂环氧底漆在钢管表面涂刷的宽度不够，或者两端没有涂到底漆。导致热缩套的边缘没能很好的粘结住。

    2，可能是烘烤不均匀，热缩套两端未能很好受热，导致没有完全收缩到钢管上，这样就没法很好的粘结钢管表面。烘烤均匀，受热不均匀，热缩套内表面的热熔胶没完全融化。这种情况是比较常见的，由于好多施工人员第一次使用，就是不知道要加热多少时间才算完成，因此很多时候往往没有加热到位就停止加热了。

     解决方法：面对上面两种情况，首先我们要在钢管表面尽量把环氧底漆涂刷的薄一点，涂刷的宽度可以适当的超出热缩套的宽度。热缩套收缩回来，没有原来宽，但是我们还是建议要涂刷的稍微宽一点。另外还有一点是我们对热缩套加热烘烤时，由中间向两端烘烤一定要充分烘烤，加热要环向均匀，直至热缩套的两端有胶水均匀溢出。