According to the domestic level and current state of spraying aluminum sheet, there are the following deficiencies in quality:
Chromatic aberration
Different batches of paints have serious differences in color; non-disposable coherent operations, for batch coating, spraying time, paint temperature and humidity are also different, there will be color; and coating thickness error, after a certain number of years will also be used Color difference.
Processing
Domestic aluminum plates are often folded in order to pursue aesthetics despite the processing performance of the aluminum plate itself, and small cracks are generated at the folds. After a period of use, some safety problems are likely to occur.
Leveling
After the flattening of the domestic plate, the positive and negative waves of the flat plateau are as high as 4mm; after forming, the flat plateau is deformed by high-temperature spraying. Therefore, the surface of the sprayed board will be extremely uneven.
The main difference between the two lies in the different stages and processes of painting.
When the pre-roll coating is in the form of a substrate or a roll, it is passed through the pickling and equalizing process on the assembly line, and the thickness of the lacquer layer is controlled by a computer. The baking is completed in a relatively closed space by several baking and baking. After rolling, it is a roll of aluminum sheet with paint. If it is used according to the size of direct cutting and bending, you can construction.
Spraying is done according to the specifications specified in the construction drawings. After cutting and bending the aluminum plate without paint, it is painted with a spray gun.
For the metal aluminum curtain wall on the market, there are many varieties. For the coating layer, it is mainly divided into spray coating, pre-roll coating and electroplating. Comprehensive performance comparison is that spraying is far lower than pre-roll coating, pre-roll coating is lower than electroplating on some indicators; in space, domestic production is mainly spraying, foreign is pre-roll coating products dominated, and electroplating products are also early in foreign countries. Someone used it. Why does this happen at home and abroad? The main reasons are the following two aspects:
Capital, technology and equipment.
There are many domestic curtain wall companies, small scales, and a mixture of fish and dragons, and there is no shortage of workshop-style production. For a multi-billion dollar roller coating production line and strict technical support requirements, it is obviously not yet available.
Architectural concept and market concept factors. That is, man-made disasters. Building is a century-long plan. It is only talking about it. Everyone cares about immediate interests and does not speak about long-term benefits. (One example is a real estate project in Shanghai's Lujiazui. The price of more than one hundred and ten thousand square meters has only been pulled down by aluminum-plastic panels, reducing costs, and the results have been traded.) Owners and laymen, manufacturers have to fight prices, cut corners, lower wages, sacrifice quality, technology research and development and upgrading is even more nonsense, and the result is that the industry as a whole has stopped.
1***H** - refers to a pure aluminum plate containing 99% pure aluminum
2***H** - refers to aluminum copper alloy
3***H** - refers to aluminum manganese alloy
4***H**——Al-Si Alloy
5***H** - aluminum-magnesium alloy, can be used as a ship or bullet-proof aluminum.
H1* - static fire (also called later fire);
H2* - dynamic fire (continuous fire on the production line, also called the middle fire);
H3* - internal stress treatment;
H4* - The above three are all as long as the coating is 4.
H*2, H*4, H*6—the latter numbers are hardness ratios. The smaller the number, the lower the hardness;
Puki aluminum magnesium board is a pre-rolled coating board, not AA5754H44 base material for coating board. The performance of 2.0mm thickness products has been outstanding. It adopts continuous three-painting and three-baking technology, anti-aging and paint-removing, coating fluorine. Carbon resin content of 70% or more, galvanized steel ribs, flexible connection, high strength, no deformation
An external wall material provided by the China Insurance Company for a 10-year warranty
First, aluminum-magnesium alloy plate
1. Substrate Model: AA5754H44, Thickness: 2.0mm, Width: Standard 1100/1250mm, 750-1500mm, Length: Standard 1000-3000mm.
2. Substrate performance:
Tensile strength: 230MPa-280MPa
Yield strength: 180MPa
Elongation: 6%
Bending performance: the inner radius is 2 times the thickness of the plate
Second, the front coating
KYNAR500 (70% or more of fluorocarbon resin) advanced super weathering fluorocarbon resin top coat.
Third, coating, film thickness
The use of high-tech roller coating method; three consecutive coating three baking, coating thickness 40uM ± 3uM.
Fourth, the back of the primer
Chrome/etch paint
Fifth, processing
1. The ribs are made of galvanized steel sheet of 1.0. The connection uses structural adhesive/construction-specific adhesive tape.
2. The use of high-precision CNC folding, shearing, and punching machine tools, equipped with a special mold that meets the hemming performance of the sheet.
3. Wind pressure load and stiffener calculation, sample inspection.
2.0mmAA5754H44 fluorocarbon pre-roll coating aluminum magnesium alloy outer wall plate
8mm -50mm honeycomb inside/outside wall panels
0.5mm-1.5mm indoor ceiling ceiling
0.3~1.5mm indoor polyester pre-rolling board
Long, square, shaped metal ceiling
Aluminum alloy exterior aluminum sheet.