The first prerequisite for the aging or photochemical
If the application of color steel coils is too long or not applied for a long time, it will cause aging, and long-term engineering construction or storage will be exposed to sunlight. Long-term direct exposure to light produces aging, which is hard to prevent, but people can usually prevent the aging rate from being reduced early. How should people do it?
The first prerequisite for the aging or photochemical reaction of the color steel coil is that the surface layer of the color steel coil can digest and absorb the radiation; secondly, when the radiant energy absorbed by the molecular structure absorbs more than the molecular structure bond energy, the color steel coil coating can dissolve. Because the light wavelength of the light source is less, the kinetic energy it contains is higher.
According to this basic theory, the embrittlement caused by the color steel coil in the air pollution is that the molecular structure of the coating absorbs and absorbs the kinetic energy of the ultraviolet light band in the natural light higher than the bond energy of the molecular structure, resulting in dissolution of the molecular structure of the plating layer. With the aging of the polyurethane coating, the base material itself is slowly missing, and the surface layer of the coating gradually becomes unsmooth and loses light. This type of loss of the base material leaves a relatively smooth paste body, which remains in the unbonded powder form to the surface of the polyurethane coating. This process is called delamination.
In general, there is a big difference in the anti-aging properties of the thin and thick polyester steel coils. The anti-aging work ability of the thin-coated color steel coils is weak, and the anti-aging characteristics of all normal thin and thick coatings are relatively good.