How to deal with it to avoid serious corrosion of color […]
How to deal with it to avoid serious corrosion of color-coated board?
After a period of use, due to the influence of various environmental factors, the coating performance and service life of the color-coated plate will be reduced, and it needs to be re-coated. The most basic requirement for regeneration is to have a certain Coated sheet factory adhesion with the original coating and good durability.
Outdoor color-coated panels can be divided into three categories according to the use environment!
The first type is used in the natural environment, which requires a certain anti-corrosion effect. For example: the construction site is isolated with color steel plates;
The second category, used in natural environments, has certain corrosion resistance and appearance effects. For example: outdoor activity board room;
The third category is used in some harsh environments and requires a certain number of anti-corrosion years.
The adhesion of different color-coated plates can be used to determine the coating system for the overcoating of color-coated plates. The coating surface of the polyester amino system contains a large amount of hydroxyl and amino groups. The color-coated panels of buildings are mostly semi-gloss coatings. The coating contains a large amount of filler or matting powder. The coating has a certain degree of roughness in a microscopic state. .. It is easy to hydrogen bond with the groups on the coating to realize the dovetail wedge effect and strong adhesion..
According to the theory of surface wetting, the surface tension of the selected repair layer must be lower than that of the color coating to facilitate wetting; the repair layer must contain polar groups that can form hydrogen bonds; the repair layer must contain a strong solvent to Enlarging the smoothness of the color coating and improving the adhesion between layers; at the same time, the repair coating can use a resin with a lower molecular weight or reduce the viscosity of the repair coating. The slow volatile solvent and low crosslinking rate coating can improve its application on the color coating board. On the adhesion.