The problem of uneven thickness of anti-corrosion coating on spiral steel pipes and how to deal with it

The problem of uneven thickness of anti-corrosion coating on spiral steel pipes and how to deal with it Spiral steel pipes are mainly used as fluid pipes and piling pipes. If the steel pipe is used for water drainage, it will generally undergo anti-corrosion treatment on the inner or outer surface. Common anti-corrosion treatments include 3pe anti-corrosion, epoxy coal tar anti-corrosion, and epoxy powder anti-corrosion. Wait, because the epoxy powder dipping process is troubled by adhesion problems, the epoxy powder dipping process has never been promoted. Now, with the successful development of the special phosphating solution for epoxy powder dipping, the adhesion problem of the epoxy powder dipping process has been overcome for the first time, and the emerging process of epoxy powder dipping has begun to appear. Analyzing the causes of uneven anti-corrosion coating thickness on spiral steel pipes, the uneven thickness of 3PE spiral steel pipe coatings is mainly reflected in the uneven thickness of test points on each side distributed in the circumferential direction. The industry standard SY/T0413-2002 has no rules for thickness uniformity. It stipulates the thickness value of the coating but requires that the thickness value of the coating cannot be lower than the thickness value of a point, rather than the average value of multiple test points. If the coating thickness is uneven during the coating process of spiral steel pipes, the coating material will inevitably be wasted. This is because when the thickness of the coating at the thinnest part reaches the specification, the thickness of the thick part will be greater than the Coating specification thickness. Moreover, uneven coating can easily cause the coating thickness at the thinnest part of the steel pipe to fail to meet the specifications. The main reasons for the uneven thickness during the production process are uneven material dispensing and bending of the steel pipe. An effective way to control the uneven coating of 3PE anti-corrosion pipes is to adjust several extrusion dies to make the anti-corrosion coating thickness in several places as uniform as possible and to prevent unqualified steel pipes from being coated online. Wrinkles on the surface of the coating: Extrusion and winding of the polyethylene material onto the steel pipe requires the use of a silicone roller. Improper adjustment during this process may cause wrinkles on the surface of the coating. In addition, the rupture of the melt film when the polyethylene material leaves the exit die during the extrusion process will also produce quality defects similar to wrinkles. The corresponding control methods for the causes of wrinkles include adjusting the hardness and pressure of the rubber roller and the pressure roller. From this perspective, appropriately increase the extrusion amount of polyethylene to control melting film rupture. Post time: Jan-29-2024