Appearance inspection of heat shrinkable sleeve

The main material of heat shrinkable winding tape is polyethylene, so it has the function of protection and anti-corrosion, which can reduce the possibility of pipe being corroded. After using it, the heat shrinkable sleeve can be judged whether its construction is successful through appearance inspection. The inspection methods are as follows:

1. Can be through the appearance inspection is and heat shrinkable sleeve edge bonding is not firm. Generally, the reason of the edge bonding is that the primer on the surface of the steel pipe is not uniform, and the heat shrinkable sleeve or the edge of the sleeve is not coated. When brushing the primer again, you can slightly paint the ratio and the sleeve width. Or the hot melt adhesive does not overflow evenly and does not work at the edge. The edge is warped, and the water can penetrate into it, so the sealing and anti-corrosion effect can not be achieved. If there are wrinkles on the surface of the sleeve, it needs to be baked again and flattened with rollers.

2. After the completion of construction, if bubbles are produced in 3PE coating, these bubbles can not exist under normal conditions. Know that the polyethylene coating with bubbles is more vulnerable to impact damage, the surface will be arched, damaged. At this time, it is necessary to roll the surface with rollers from the middle to both ends to drive out bubbles. In addition, the hollowing phenomenon of the heat shrinkable sleeve is unavoidable in the three-layer polyethylene joint coating, which can only allow the existence of small-scale hollowing. At present, the quantitative method is to link the allowable hollowing size with the allowable peel strength.

3. If the sleeve is cracked, it means that the construction has failed. At this time, it is necessary to clean them from the surface of the steel pipe and re select the heat shrinkable sleeve for construction.

To sum up, the appearance inspection of heat shrinkable sleeve can judge whether the construction is successful or not, also can judge their anticorrosion degree, and also can reduce the occurrence of accidents. Its inspection work is an indispensable work after construction, which is worthy of attention.