The galvanized sheet may be aged if it is used for too long or not used for a long time. Why do you say that? Long-term construction or storage will inevitably expose to sunlight. After long-term light exposure, aging will occur, which is inevitable, but we can prevent and reduce the aging speed in advance, so what should we do?
A necessary condition for the aging or photochemical reaction of the color-coated board is that the surface components of the color-coated board can absorb radiant energy. Secondly, when the radiation energy absorbed by the molecules is greater than the bond energy of the molecules, the coating of the color-coated board will degrade. The shorter the wavelength of light, the more energy it contains.
According to the above theory, the aging of the color-coated board in the atmospheric environment is that the ultraviolet light band energy absorbed by the coating molecules is higher than the molecular bond energy in the sunlight, resulting in the degradation of the coating molecules. With the aging of the coating film, the body of the substrate is gradually lost, and the surface of the coating gradually becomes rough and loses its luster. The loss of binder eventually leaves stable pigment particles that remain on the surface of the coating film as an unbound powder, a process called pulverization.
To sum up, the aging resistance of polyester color-coated boards with different coating thicknesses varies greatly, the aging resistance of thin-coated color-coated boards is poor, and the aging resistance of ordinary coating thicknesses is relatively good.
Furthermore, it is not feasible to reduce the production cost of color-coated sheets by thinning the coating, which will inevitably bring about serious quality problems. At the same time, it is also demonstrated from the side that it is necessary to clearly indicate the coating thickness in the order contract of foreign color-coated sheet importers.
With the development of my country’s construction industry, the related building materials industry has a broader space for development. Galvanized sheet has been recognized by many users in the market for its unique advantages.
Galvanized steel sheet is cold rolled or hot rolled, and the slender steel sheet is coated with a layer of zinc of varying thickness. The production of galvanized sheet concentrates the advantages of galvanized sheet and strip, so that the product is not only corrosion-resistant and beautiful, but also has high dimensional accuracy, good surface quality, easy processing and material saving. To a certain extent, the products can meet the needs of the public and better meet the needs of users.