3PE anticorrosive pipe is used in different working environment. In order to slow down or prevent the corrosion and deterioration of the pipe under the chemical and electrochemical action of the external medium or the metabolic activity of microorganisms, two or three layers of polyethylene (3PE) are coated on the outer wall of the pipe to achieve the anticorrosion of the pipe. The service life of 3PE anticorrosive pipe is extended by 3-5 times.
Polyethylene three-layer structure protective coating, also known as three-layer PE (3pe), is an advanced anti-corrosion technology introduced from abroad in recent years.
Its full name is fused epoxy/extruded polyethylene structural protective layer, which consists of three layers: the bottom layer is fused epoxy (> 80 micron); the middle layer is adhesive (170-250 micron); and the surface layer is extruded polyethylene (about 2 mm). The total thickness of the protective layer is about 1.8-3.7 mm. In the three-layer structure, the main function of fused epoxy powder coating is to form a continuous coating and bond directly with the surface of steel pipe, which has good chemical corrosion resistance and cathodic peeling resistance, and react with the active group of the intermediate layer adhesive to form chemical bonding, so as to ensure that the overall anti-corrosion coating has good performance at high temperature. Cohesiveness. Intermediate layer is usually copolymer binder, the main component of which is polyolefin. At present, vinyl copolymer binder is widely used. The polar functional groups of copolymer adhesives can react with the epoxy groups of fused epoxy powder coatings to form hydrogen bonds or chemical bonds, which can form a good bond between the middle layer and the bottom layer. The non-polar functional groups of ethylene have a good affinity with the surface layer polyethylene, so the middle layer and the surface layer also have good bonding properties.
The main function of polyethylene surface layer is mechanical protection and anti-corrosion. It has the same function as traditional two-layer structure polyethylene.