Metal plate curtain wall has been used for decades, including aluminum veneer, aluminum-plastic composite plate and aluminum honeycomb plate. Among the three materials, the most commonly used are aluminum veneer and aluminum plastic plate. Aluminum veneer appeared first. Later, in the late 1960s and early 1970s, aluminum-plastic composite plate was invented in Germany and quickly became popular all over the world. What is the difference between aluminum plastic plate and aluminum veneer? Here, the aluminum veneer manufacturers in Eastern Europe make a simple comparison between the two materials:
1、 Materials and cost
Aluminum veneer generally adopts 2-4mm thick AA1100 pure aluminum plate or AA3003 and other high-quality aluminum alloy plate, and 2.5mm thick AA3003 aluminum alloy plate is generally used in China; Aluminum plastic composite board generally adopts 3-4mm three-layer structure, including upper and lower 0.5mm sandwiched with PVC or PE. We can see from the materials that the cost of aluminum-plastic composite plate must be much lower than that of aluminum veneer. In the market, the price of 4mm thick composite plate is more than 120 yuan / m2 lower than that of 2.5mm thick aluminum veneer. For a 10000 m3 project, the cost of using aluminum plastic plate is 1.2 million yuan lower than that of using aluminum veneer.
2、 Processing process
There are two kinds of aluminum veneers in the world: fluorocarbon spraying aluminum veneer and roller coating. There is no stick coating production line in China, so the processing process of veneer here mainly focuses on fluorocarbon spraying production. The production of aluminum veneer by spraying is divided into two steps: the first step is sheet metal processing. This process is mainly to process the aluminum veneer into the shape and size required for construction by cutting, folding, arc bending, welding, grinding and other processes. The second step is spraying. Spraying is to spray paint on the processed sheet metal. There are two types of spraying, one is manual spraying and the other is machine spraying. Machine spraying is generally only suitable for regular flat plates, but this kind of aluminum veneer is rarely used in actual use. Most domestic manufacturers use manual spraying. Manual spraying is a dangerous work, because the volatility and toxicity of paint are relatively strong, which is easy to cause chronic benzene poisoning and seriously affect people's health. One of the advantages of manual spraying is that the color can be selected regardless of the amount, and the roll coating of aluminum-plastic plate must reach a certain amount before processing. The processing process of aluminum-plastic plate is more complex than that of aluminum veneer. It mainly includes four processes: formation, coating, compounding and trimming. These four processes are automatic production except trimming. From its processing process, it can be seen that aluminum-plastic plate has certain advantages in environmental protection and safety. In addition, the sheet metal processing of aluminum veneer is simple, and some private workshops have also begun to set foot in it, which has seriously affected the stability of the market quality of aluminum veneer.
3、 Products
Item 2.5mm aluminum veneer 4mm thick aluminum plastic composite plate
Appearance quality: the flatness of the flat plate is not high, and it seems to have local concave convex. The flatness of the flat plate is relatively high, but the processing shape is limited;
But it can be processed into various irregular shapes; The spraying roller has good visual quality, color difference and film thickness deviation
Due to the instability of artificial technology, local color difference is not obvious, but the damage cannot be repaired locally.
And film thickness deviation; Local damage can be repaired.
Machine tensile strength 130 / mm 38-61n / mm2x
Mechanical elongation 5% - 10% 12% - 17%
Bending strength 84.2n/mm 34n / mm2
Elastic modulus 70.00n/mm2 26.136-49.050n/mm2
It can be seen from the above table that the appearance of aluminum veneer is worse than that of aluminum-plastic plate, but its mechanical properties are obviously better than that of aluminum-plastic plate, and its wind pressure resistance is also better than that of aluminum-plastic plate. However, in most areas of China, the wind pressure value of aluminum-plastic plate is completely bearable. Therefore, the use of aluminum veneer in engineering is a little overqualified.
4、 Construction process
The construction process of aluminum plastic plate and aluminum veneer is roughly the same. The biggest is not aluminum-plastic plate, but processed into the required shape and specification on the construction site, with a large degree of construction freedom. Aluminum veneer is processed and formed by Chinese manufacturers. Due to the accuracy of domestic equipment, we often encounter some small problems in the construction process. In addition, in terms of the guarantee of delivery date in the construction process, the batch production of aluminum-plastic composite plate is much faster than that of aluminum veneer, and the schedule guarantee system is also higher.
5、 Processing requirements
As a senior manufacturer, it must integrate scientific research, design and production. Senior manufacturers must first have an independent system, be able to quickly complete the basic design of products, have the corresponding scientific research ability, improve product shortcomings, develop new products and solve the problems encountered in reality, and then the requirements of production capacity. Requirements for sheet metal processing: a complete set of cutting, punching, bending and circular coiling machine for processing arc plates can realize the processing of sheet metal with various complex shapes with a basic size of 4m (many manufacturers can process more than 6m, but the longer the length, the worse the flatness). Aluminum argon arc welding and high-frequency welding nail equipment can ensure the high-quality completion of welding, corner sealing and reinforcing rib seed nail processes of formed aluminum plate; Mechanized grinding and polishing equipment and 6.6 × one point seven × 1m automatic pre-treatment tank and a set of 8 designed and produced exclusively × 3 meters and 8 meters × The 2m spraying room and oven can complete the processing of super large plates and long materials, and ensure that the product surface meets the film requirements of the substrate required for coating.
Spraying processing requirements: chemical pretreatment uses chemical solution to remove organic and inorganic stains on the metal surface. Then remove the natural oxide layer, and then use the chemical agent to produce the oxide film, so as to produce rust prevention and permanent paint adhesion on the metal surface. The domestic advanced automatic electrostatic spraying line is used for electrostatic coating. The fluorocarbon coating is sprayed on the metal base surface layer by layer according to the process requirements, and baked and solidified according to the specific temperature and time.
Quality assurance system requirements: high precision special testing instruments are used for quality inspection and packaging to strictly inspect the product quality, ensure that the dimensional accuracy of the product meets the enterprise standard, and the paint film quality meets the American aama-605 standard.
6、 Other aspects
1. The problem of lightning protection characteristics has been debated for a long time. People always think that aluminum veneer is pure aluminum and has better conductivity. To solve this problem, Germany's alusuisseingen GmbH conducted lightning resistance experiments of two materials in a military laboratory in Germany. The results show that the curtain wall connection mode adopted, whether aluminum plastic plate or aluminum veneer, can completely prevent lightning when lightning strikes; Under the action of continuous lightning current, melting is easy to occur at the lightning strike of metal plate or metal surface. Due to the good insulation of the middle polyethylene core layer, the damage caused by lightning is limited to the skin. From this point of view, the aluminum-plastic composite plate has better lightning resistance than the aluminum veneer.
2. The fireproof characteristic of aluminum veneer is non combustible, which is known to all. The early aluminum-plastic board was not fireproof, but with the development of aluminum-plastic board technology, the fireproof aluminum-plastic composite board produced has greatly improved its fireproof performance due to the addition of non-toxic and flame-retardant materials in its PE, which can fully meet the needs of engineering fire protection.
3. Residual value aluminum veneer has a certain residual value, but due to its high cost, it still causes much more waste than aluminum-plastic composite board with almost no residual value. To sum up the above analysis, aluminum veneer and aluminum-plastic composite plate have their own advantages, but from a large perspective, the application of aluminum-plastic plate should be more affordable and environmentally friendly.
