According to GB / T23443-2009 national standard definition of aluminum veneer for building decoration, aluminum veneer refers to the veneer layer for building decoration, which is based on aluminum or aluminum alloy, processed and formed, and the decorative surface has a protective and decorative coating or anodizing film.
At present, electrostatic spraying technology is widely used in the industry when spraying aluminum veneer, because electrostatic spraying has high requirements on the temperature and humidity of the spray room. If the control is not good, the quality of the spray coating will be greatly affected. Electrostatic spraying is divided into "powder spraying" and "liquid spraying".
After painting, drying and natural cooling, quality inspection will be carried out before delivery, mainly including film thickness test and color difference test. The main topic here is film thickness detection, which usually uses a film thickness meter. Here are a few concepts to briefly introduce, "local film thickness", "average film thickness" and "minimum local film thickness". Among them, "local film thickness" refers to the arithmetic mean value of the measurement value obtained by not less than three times of film thickness measurement in an inspection surface with an area of not more than 1 cm on the decorative surface of aluminum veneer; "average film thickness" refers to the arithmetic mean value of the local film thickness measured at not less than five places (four corners and one center point) on the decorative surface of aluminum veneer; The "minimum local film thickness" is the minimum value among thousands of local film thickness values measured on the decorative surface of aluminum veneer, which is all very important parameters.
Aluminum Veneer Application: Pedestrian Bridges
In liquid spraying, the average film thickness of the second coating of fluorocarbon spraying shall be no less than 30 μ m (1 μ m is 1 μ m, 10-6 m), and the minimum local film thickness shall be 25 μ m; the average film thickness of the third coating of fluorocarbon shall be no less than 40 μ m, and the minimum local film thickness shall be no less than 34 μ m; the average film thickness of the fourth coating of fluorocarbon shall be no less than 65 μ m, and the minimum local film thickness shall be no less than 55 μ M. The average film thickness of polyester liquid spraying is more than or equal to 25 μ m, and the minimum local film thickness is more than or equal to 20 μ M.
In powder spraying, the minimum local film thickness of fluorocarbon spraying is more than or equal to 30 μ m, and that of polyester spraying is more than or equal to 40 μ M.
