A method for fusion bonding of epoxy coating and three-layer polyethylene coating

Abstract

The invention discloses a fusion bonding method of an epoxy coating with a three-layer polyethylene coating, and belongs to the field of joint wrapping anticorrosion. The method comprises the following steps: first, removing the dirt on the surface of the three-layer polyethylene coating by water; then coating epoxy coating on the surface of the clean three-layer polyethylene coating, and heating at the temperature of 120- 260 DEG C for 20 s-20 min. The epoxy coating is a solvent-free two-component epoxy coating comprising a fatty chain structure with molecular chain length of about 36 carbon atoms. According to the invention, the three-layer polyethylene coating and epoxy coating are heated, so that the long fatty chain of the three-layer polyethylene coating and the long fatty chain of the epoxy coating twisted in the molten state and further form fusion bonding between the three-layer polyethylene anticorrosion coating and the oxygen coating; and the initial adhesion and durable adhesion of the coatings for the pipeline joint wrapping anticorrosion are improved, and the quality of joint wrapping anticorrosion is improved.

Description

technical field [0001] The invention relates to the field of anti-corrosion of joints, in particular to a method for melting and bonding an epoxy coating and a three-layer polyethylene coating, which is used in the anti-corrosion technology of pipeline joints. Background technique [0002] The quality of the anti-corrosion quality of the buried long-distance oil and gas pipeline is the key to the quality control of the pipeline anti-corrosion. Among the existing various filling materials, the solvent-free two-component epoxy coating has the advantages of simple coating process, easy repair, reliable inspection results, and no cathodic protection current shielding, so it has developed rapidly. [0003] At present, most buried long-distance pipelines use three-layer polyethylene anti-corrosion layers. Polyethylene is a typical non-polar material with low surface energy. Solvent-free two-component epoxy coatings for pipeline repair and corrosion protection are usually compose...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problem that the existing technology cannot improve the durable bonding force between the joint coatings and cannot meet the long-term service requirements of buried long-distance pipelines, the embodiment of the present invention provides an epoxy coating and a three-layer polyethylene coating Fusion bonding method, which uses a solvent-free two-component epoxy coating containing an aliphatic chain structure with a length of about 36 carbon atoms, and heats it at a high temperature to form a fusion bond with the three-layer polyethylene anti-corrosion coating. Bonded together in a knotted way, which improves the cohesion between the joint coating and the three-layer polyethylene coating, and ensures that the long-term high cohesion between the anti-corrosion coatings in the joint joint area of ​​the pipeline meets the requirements of buried The demand for long-term service of long-distance pipelines