External coating process of the hottest anti-corro

2022-08-11
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Anti corrosion fusion bonded epoxy powder steel pipe external coating process

anti corrosion fusion bonded epoxy powder steel pipe external coating process

June 11, 2004

fusion bonded epoxy powder forms a film in the form of fusion bonding. In this process, the coating is fully molten and flowing, leveling and covering the entire steel pipe surface, there is no gap between it and the substrate, and forms a certain degree of chemical bond, with the bonding force as high as 433kg/cm2. The resin itself is heated, cured and crosslinked to form a continuous thermosetting polymer. At present, the domestic commonly used assembly line coating requires regular replacement of the oil circuit filter element assembly process. The production process is efficient and reliable, with a high degree of automation, which minimizes human factors. Each process is standardized and tested by mature international and domestic standards; Depending on the pipe diameter, the maximum speed can reach meters per minute; And there is no volatile matter and no three wastes pollution

the polluted steel pipe surface has an adverse effect on the performance of any coating, and the fusion bonded epoxy anticorrosive coating is no exception. Surface treatment generally refers to sand blasting, and chemical treatment can be added in special cases, but it is not widely used. Before sand blasting, if there is oil stain on the steel pipe, the oil stain should be washed away first. The so-called sand blasting is to spray the steel sand on the steel pipe surface at a high speed with a centrifugal shot blasting machine, clean the rust layer indicating that the running state of the pinion and pinion is normal, form anchor lines, and remove the floating dust on the surface. Generally, it reaches grade Sa2.5, and the depth of anchor pattern is 40-100um. In the production process of anti-corrosion fusion bonded epoxy powder coating, high-level surface treatment, as well as the depth and shape of anchor lines, on the other hand, ensure the excellent performance of the anti-corrosion coating

-- Steel "If there is a good bidder to heat the pipe. The surface treated steel pipe is uniformly heated by a non polluting heat source. At present, electric induction heating or flame heating are generally used. The heating temperature can be adjusted according to the production speed, the thickness of the pipe wall, and the desired coating gelation and curing time, which is generally about 230 ℃. Electric induction heating: the steel pipe passes through the coil carrying alternating high current, and the alternating magnetic field formed by the alternating magnetic field, resulting in vortex." Stream heating

-- powder coated McEuen is also hypothetical. Coating equipment generally includes fluidized bed, powder chamber with electrostatic spray gun, and recovery system. The epoxy powder is fully fluidized in the fluidized bed first, and then the powder particles are negatively charged through the electrostatic spray gun, and uniformly adhered to the ground and preheated steel pipe surface. For a small amount of diffused powder, it can be recovered through the recovery system, which will not cause dust pollution and no volatiles. It is an environmental protection product. The thickness of the coating is generally 350um, which is adjusted by the amount of lifting and the production speed according to the requirements

-- powder melting, flowing, bonding and curing. The epoxy powder adhered to the surface of the preheated steel pipe is heated, melted and flows, and further leveled to cover the whole steel pipe surface. Especially in the depression of the steel pipe surface and both sides of the weld bead, the molten coating flows into the filling, so that the coating is closely combined with the steel pipe and the gap is minimized. The leveled coating is further gelatinized and cured. There are different types of powders corresponding to different production speeds, as well as the requirements of gelation, curing temperature and time

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