If China Galvanized Steel Roofing Sheet for sale is used for too long or not used for a long time, it may age. Why do you say that long-term construction or storage must be exposed to the sun? After a long period of exposure to light, aging will occur, which we can't avoid, but we can prevent the speed of aging in advance, so what should we do?
The first necessary condition for the aging or photochemical reaction of the color-coated plate is that the surface component of the low price color corrugated steel sheet can absorb the radiant energy; secondly, when the radiant energy absorbed by the molecule is greater than the molecular bond energy, the coating of the color-coated plate can be degraded. The shorter the wavelength of the light, the higher the energy it contains.
According to the above theory, the aging of the low price color corrugated steel sheet in the atmospheric environment is that the coating molecule absorbs energy in the ultraviolet light band of the solar light higher than its molecular bond energy, resulting in degradation of the coating molecule. As the coating film ages, the base body gradually loses, and the surface of the coating gradually becomes rough and loses light. This loss of the binder ultimately leaves relatively stable pigment particles which remain as unbonded powder on the surface of the coating film, a process known as pulverization.
In summary, polyester coatings with different coating thicknesses have great differences in aging resistance, thin coatings have poor aging resistance, and normal aging coatings have relatively good aging resistance.
Therefore, the method of reducing the production cost of the color-coated plate by reducing the coating is not feasible, which will inevitably bring serious quality problems. At the same time, it also demonstrates from the side that the coating thickness of the foreign cheap color corrugated steel sheet in stock importer clearly indicates the coating thickness.
