The bottom layer of 3PE anti-corrosion is epoxy coating, the middle layer is polymer adhesive, and the surface layer is polyolefin. Adhesives can be modified polyolefins, which contain polar groups grafted onto the main chain of the polyolefin carbon bonds. In this way, the adhesive can not only be fused with the surface unmodified polyolefin, but also can use the polar group to react with the epoxy resin. This combination is characterized by the best bonding strength between the three coatings, and the performance and characteristics of each layer make the three coatings complementary. It is characterized by high cost and complex process.
A layer of epoxy powder (FBE>100um) (epoxy powder >100um means greater than 100 microns);
Two-layer adhesive (AD) 170～250um;
Three-layer polyethylene (PE) 2.5～3.7mm.
The three materials are integrated and firmly combined with the steel pipe to form an excellent anti-corrosion layer.
The 3PE anti-corrosion layer organically combines the anti-corrosion properties of the fused epoxy powder with the mechanical scratch protection properties of polyethylene, and at the same time solves the problem of polyethylene's sales. Due to the poor adhesion of the hot melt adhesive, the peeled polyethylene has a shielding effect on the cathodic protection. 3PE anti-corrosion layer has high requirements on the surface treatment state of the pipe, and the depth of the anchor pattern should reach 50μm～75μm. Whether the side will affect the cathodic stripping resistance and waterproof penetration ability of the anti-corrosion layer.
2PE anti-corrosion: one layer of adhesive (AD), two layers of polyethylene (PE), the two materials are integrated, the thickness of each layer is the same as that of the three layers of PE
SY/T0413-2002 Technical Standard for Polyethylene Anticorrosive Coating for Buried Steel Pipeline
GB/T23257-2009 Technical Standard for Polyethylene Anticorrosive Coating for Buried Steel Pipelines