Roller coating process of an ultra-thick coating color-coated steel plate

Abstract

The invention discloses a roller coating process of an ultra-thick coating color-coated steel plate. The roller coating process comprises at least two primer coating steps and at least two finish paint coating steps. In the first primer coating step, the pressure between a primary coating roller and a primary coating material roller is controlled to be 1600-1800kg. After the first primer coating step, the steel plate is baked by a baking oven, the interior of the baking oven is divided into a first baking area, a second baking area, a third baking area, a fourth baking area and a fifth bakingarea in sequence in the moving direction of the steel pipe, wherein the baking temperature in each baking area is sequentially increased. In the second primer coating step, the pressure between a finish coating roller and a finish coating material roller is controlled to be 1600-1800kg. After the second primer coating step, the steel plate is baked by the baking oven. The moving speed of the steelplate is controlled within 55-65mpm in the first primer coating step, the second primer coating step and baking steps afterwards.

Description

technical field [0001] The invention relates to a roll coating process, in particular to a roll coating process for color-coated steel plates. Background technique [0002] The coating thickness of color-coated products is closely related to the corrosion resistance of the product. The thicker the coating, the better the corrosion resistance and weather resistance of the product. The thickness of the fluorocarbon coating increases from 20 microns to 50 microns. Fog and QUVB UV aging properties are more than doubled. [0003] At present, the film thickness of the two-coating and two-baking roller-coated color-coated product in the prior art ranges from 15 to 25 microns, and the thickest coating thickness that can be achieved by roller coating of this two-coated product does not exceed 30 microns. This is because, unlike spray coating, if the film thickness continues to increase when roller coating is used, not only will there be problems with coating, but also defects such a...

AI Technical Summary

Problems solved by technology

[0003] At present, the film thickness of the two-coating and two-baking roller-coated color-coated product in the prior art ranges from 15 to 25 microns, and the thickest coating thickness that can be achieved by roller coating of this two-coated product does not exceed 30 microns. This is because, unlike spray coating, when the film thickness continues to increase when the roller coating method is used for production, not only will there be problems with coating, but also defects such as streaks and bubbles will easily appear on the coating surface.

Therefore, thick coating products above 30 microns are generally achieved by three-coating or four-coating methods, but even with four coatings, the thickest film thickness that can be achieved cannot exceed 70 microns, because The performance and baking process of the first and second layers of coatings will have a more obvious impact on the surface of the subsequent coating when baking multiple coatings. The specific manifestations are poor interlayer adhesion and surface air bubbles. Especially the problem of surface air bubbles is very difficult to solve, which directly limits the thickness of each layer of the first and second layers of coating to no more than 15 microns, and the thickness of each layer of the third and fourth layers is generally only 15 microns. Can be around 20 microns

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